[DWARFLinkerParallel] Add limited functionality to DWARFLinkerParallel.

[avl]

Summary

This patch is extracted from D96035, it adds support for the existing
DWARFLinker functionality. What is not supported yet:

1. Types deduplication(--odr mode).
2. Modules deduplication.
3. Generation of index tables.

run-time performance and memory requirements for clang binary --num-threads 16 :

----------------------------------------------------------------------------------
                                                      |  time, sec   |  mem, GB  |
----------------------------------------------------------------------------------
dsymutil --no-odr --accelerator None --linker llvm    |      44      |   18.0    |
----------------------------------------------------------------------------------
dsymutil --no-odr --accelerator None --linker apple   |     248      |   22.2    |
----------------------------------------------------------------------------------

run-time performance and memory requirements for clang binary --num-threads 1 :

----------------------------------------------------------------------------------
                                                      |  time, sec   |  mem, GB  |
----------------------------------------------------------------------------------
dsymutil --no-odr --accelerator None --linker llvm    |     242      |   17.2    |
----------------------------------------------------------------------------------
dsymutil --no-odr --accelerator None --linker apple   |     260      |   19.4    |
----------------------------------------------------------------------------------

The overall linking process looks like this:

parrallel_for_each(ObjectFile) {
  for_each (Compile Unit) {
    1. Load Clang modules.
  }

  parrallel_for_each(Compile Unit) {
    1. Load input DWARF for Compile Unit.
    2. Report warnings for Clang modules.
    3. Analyze live DIEs.
    4. Clone DIEs(Generate output DIEs and resulting DWARF tables).
        The result is set of sections corresponding to the current compile unit.
    5. Cleanup Input and Output DIEs.
  }

  Deallocate loaded Object file.
}

for_each (ObjectFile) {
  for_each (Compile Unit) {
    1. Set offsets to Compile Units DWARF sections.
    2. Sort offsets/attributes/patches to have a predictable result.
    3. Patch size/offsets fields.
    4. Generate index tables.
    5. Move DWARF sections of compile units into the resulting file.
 }
}

Every compile unit is processed separately, visited only once
(except case inter-CU references exist), and used data is freed
after the compile unit is processed. The resulting file is glued together
from the generated debug tables which correspond to separate compile units.

Handling inter-CU references: inter-CU references are hard to process
using only one pass. f.e. if CU1 references CU100 and CU100 references
CU1, we could not finish handling of CU1 until we finished CU100.
Thus we either need to load all CUs into the memory, either load CUs several
times. This implementation loads inter-connected CU into memory at the first
pass and processes them at the second pass.

Changes from the current implementation(making DWARFLinkerParallel to be binary incompatible with current DWARFLinker):

a) No common abbreviation table. Each compile unit has

its own abbreviation table. Generating common abbreviation table slowdowns parallel execution(This is a resource that is accessed many times from many threads). Abbreviation table does not take a lot of space, so it looks cheap to have separate abbreviations tables.
Later, it might be optimized a bit(by removing equal abbreviations tables).

b) .debug_frame. Already generated CIE records are not reused between object files

c) location expressions, containing type references, use fixed-length ULEB128 format as they need to be patched after reference body is generated.

d) live tracking algorithm does not depend on the order of DW_TAG_import_module nodes and in some cases keep more DIEs.

[clayborg]

a) No common abbreviation table. Each compile unit has its own abbreviation table. Generating common abbreviation table slowdowns parallel execution(This is a resource that is accessed many times from many threads). Abbreviation table does not take a lot of space, so it looks cheap to have separate abbreviations tables. Later, it might be optimized a bit(by removing equal abbreviations tables).

Can't we just let each compile unit generate its own abbrev table and then unique them into a single abbrev table at when we write out the .debug_info data? That way compile units can stay fast in parallel execution, and since we need to emit the compile units serially when generating the .debug_info, we can just have a map that maps CU specific abbrev codes to the global and final abbrev list? Then we end up with just one .debug_abbrev table in the end

[avl]

In D153268#4435883, @clayborg wrote:

a) No common abbreviation table. Each compile unit has its own abbreviation table. Generating common abbreviation table slowdowns parallel execution(This is a resource that is accessed many times from many threads). Abbreviation table does not take a lot of space, so it looks cheap to have separate abbreviations tables. Later, it might be optimized a bit(by removing equal abbreviations tables).

Can't we just let each compile unit generate its own abbrev table and then unique them into a single abbrev table at when we write out the .debug_info data? That way compile units can stay fast in parallel execution, and since we need to emit the compile units serially when generating the .debug_info, we can just have a map that maps CU specific abbrev codes to the global and final abbrev list? Then we end up with just one .debug_abbrev table in the end

The problem with this solution seems that when local abbreviation number would be replaced with global number(which is ULEB128 format) the DIEs offsets will be changed(because size of global number may differ from the size of local number). It will brake all sizes and references.

Also, currently CU is emitted(when we write out the .debug_info data) immediately. The global abbreviation table might be done in the very end after all CUs are emitted. That means we need to parse already emitted CU and update abbreviation numbers. It would probably slowdown execution.

The size of abbreviation table for clang binary having .debug_info 1.7G : 12.5K for DWARFLinker and 7.2M for DWARFLinkerParallel. i.e. new abbreviation table is approx 0.5% of overall .debug_info size. It looks relatively cheap. Though, any solution making .debug_abbrev shorter would certainly be good. Probably we might experiment with fixed length abbreviation numbers...

[avl]

Another solution might be to use abbreviation table from already generated CU for the next CU. So that in any concrete moment current CU owns abbreviation table, but finally single abbreviation table would be shared between several CUs. That way, there still would exist several tables but some of them would be shared. It would reduce current size of .debug_abbrev.

[clayborg]

In D153268#4435984, @avl wrote:

In D153268#4435883, @clayborg wrote:

a) No common abbreviation table. Each compile unit has its own abbreviation table. Generating common abbreviation table slowdowns parallel execution(This is a resource that is accessed many times from many threads). Abbreviation table does not take a lot of space, so it looks cheap to have separate abbreviations tables. Later, it might be optimized a bit(by removing equal abbreviations tables).

Can't we just let each compile unit generate its own abbrev table and then unique them into a single abbrev table at when we write out the .debug_info data? That way compile units can stay fast in parallel execution, and since we need to emit the compile units serially when generating the .debug_info, we can just have a map that maps CU specific abbrev codes to the global and final abbrev list? Then we end up with just one .debug_abbrev table in the end

The problem with this solution seems that when local abbreviation number would be replaced with global number(which is ULEB128 format) the DIEs offsets will be changed(because size of global number may differ from the size of local number). It will brake all sizes and references.

We make up DIEs to emit, but _as_ we emit the DIEs from a CU, can't we globalize the abbrev from the local CU as they are being emitted? Each abbrev could cache its global value if it has already been emitted from each CU. I am thinking that DIEs would have references to other DIEs using pointers when they are stored in intermediate form but this might not be true coming to think about it. If reference would need to be updated then this wouldn't work as you mentioned.

Also, currently CU is emitted(when we write out the .debug_info data) immediately. The global abbreviation table might be done in the very end after all CUs are emitted. That means we need to parse already emitted CU and update abbreviation numbers. It would probably slowdown execution.

Yeah, if DIE refs are done with hard coded offsets up front then this wouldn't work. A DWARF generator a created in python has references pointing to a DIE object so that it can ask that object for its offset when a reference is needed, and if it isn't available yet, it gets added to a fixup list for forward refs, and then they get fixed up in a post CU output phase. This is nice because I never have to worry about reference offsets as they "just work". I admit I am not as familiar with out the LLVM DWARFLinker does things.

The size of abbreviation table for clang binary having .debug_info 1.7G : 12.5K for DWARFLinker and 7.2M for DWARFLinkerParallel. i.e. new abbreviation table is approx 0.5% of overall .debug_info size. It looks relatively cheap. Though, any solution making .debug_abbrev shorter would certainly be good. Probably we might experiment with fixed length abbreviation numbers...

No real worry if the size isn't too big.

[clayborg]

In D153268#4436009, @avl wrote:

Another solution might be to use abbreviation table from already generated CU for the next CU. So that in any concrete moment current CU owns abbreviation table, but finally single abbreviation table would be shared between several CUs. That way, there still would exist several tables but some of them would be shared. It would reduce current size of .debug_abbrev.

I like this idea. Not needed for this patch, but sounds like a good idea.

[avl]

In D153268#4436350, @clayborg wrote:

In D153268#4435984, @avl wrote:

In D153268#4435883, @clayborg wrote:

a) No common abbreviation table. Each compile unit has its own abbreviation table. Generating common abbreviation table slowdowns parallel execution(This is a resource that is accessed many times from many threads). Abbreviation table does not take a lot of space, so it looks cheap to have separate abbreviations tables. Later, it might be optimized a bit(by removing equal abbreviations tables).

Can't we just let each compile unit generate its own abbrev table and then unique them into a single abbrev table at when we write out the .debug_info data? That way compile units can stay fast in parallel execution, and since we need to emit the compile units serially when generating the .debug_info, we can just have a map that maps CU specific abbrev codes to the global and final abbrev list? Then we end up with just one .debug_abbrev table in the end

The problem with this solution seems that when local abbreviation number would be replaced with global number(which is ULEB128 format) the DIEs offsets will be changed(because size of global number may differ from the size of local number). It will brake all sizes and references.

We make up DIEs to emit, but _as_ we emit the DIEs from a CU, can't we globalize the abbrev from the local CU as they are being emitted?

We can, but after abbrev numbers are globalized we need to update all size and reference fields and rewrite emitted DWARF.

Each abbrev could cache its global value if it has already been emitted from each CU. I am thinking that DIEs would have references to other DIEs using pointers when they are stored in intermediate form but this might not be true coming to think about it. If reference would need to be updated then this wouldn't work as you mentioned.

this patch uses Codegen DIE. It does not use pointers for references/sizes/offsets. These are absolute values:

DIE::setOffset()
DIE::setSize()
DIE::addValue(DIEAlloc, dwarf::Attribute(AttrSpec.Attr), dwarf::DW_FORM_ref_addr, DIEInteger(0x0)))

Also, currently CU is emitted(when we write out the .debug_info data) immediately. The global abbreviation table might be done in the very end after all CUs are emitted. That means we need to parse already emitted CU and update abbreviation numbers. It would probably slowdown execution.

Yeah, if DIE refs are done with hard coded offsets up front then this wouldn't work. A DWARF generator a created in python has references pointing to a DIE object so that it can ask that object for its offset when a reference is needed, and if it isn't available yet, it gets added to a fixup list for forward refs, and then they get fixed up in a post CU output phase. This is nice because I never have to worry about reference offsets as they "just work". I admit I am not as familiar with out the LLVM DWARFLinker does things.

Yes. that is the case - DIEs emitted before global abbreviations are known. This patch does similar fixup handling for references(write proper values later, when they are known). But that fixup occurs for fixed-size fields. For patching variable size fileds(like LEB128) it is necessary to rewrite already generated DWARF(as we need to shift data because of changed fields length).

The size of abbreviation table for clang binary having .debug_info 1.7G : 12.5K for DWARFLinker and 7.2M for DWARFLinkerParallel. i.e. new abbreviation table is approx 0.5% of overall .debug_info size. It looks relatively cheap. Though, any solution making .debug_abbrev shorter would certainly be good. Probably we might experiment with fixed length abbreviation numbers...

No real worry if the size isn't too big.

[avl]

In D153268#4436351, @clayborg wrote:

In D153268#4436009, @avl wrote:

Another solution might be to use abbreviation table from already generated CU for the next CU. So that in any concrete moment current CU owns abbreviation table, but finally single abbreviation table would be shared between several CUs. That way, there still would exist several tables but some of them would be shared. It would reduce current size of .debug_abbrev.

I like this idea. Not needed for this patch, but sounds like a good idea.

Though there is some difficulty with this solution. The binary content would be non-deterministic. As it can not be guaranteed which CU share which abbreviation table.

Do we need to preserve binary representation to be deterministic(byte to byte equal between runs)?

Probably we could use special dumping which would be deterministic? Like dumping from https://reviews.llvm.org/D124082. In spite of the fact that source files are not byte to byte equal - the contents of the dump would be byte to byte equal.

[JDevlieghere]

I don't have all of dsymutil paged in to do a really thorough/meaningful review of all the details. Even if I did I'm sure a bunch of stuff would slip through that would only be caught by real world qualification.

At a high level I think the approach makes sense. I've spent quite a bit of time thinking of alternatives and I cant't think of anything more efficient given the constraints that we have (i.e. not being able to keep all the input DWARF concurrently in memory).

As for the implementation itself:

• I like that you factored out things like the attribute cloning and I wonder if we could hoist this up and make it work with the non-parallel linker as well. I don't think we should go to extreme lengths to unify the two implementations, but even if we were to switch over to the new (parallel) implementation tomorrow, I expect the old one to be around for at least a few more years and I'd hate to have to maintain both.
• I wonder if we could make the stages more explicit. If I'm reading the code right, the data (i.e. the DIE) and the logic (i.e. the live analysis) are shared in the same class and we have to maintain state. I would prefer a design where the two are decoupled and the data moves through the different stages. The way I'm imagining this is to have a class for every stage, possibly with its own shared context, and then have the DIEs move through them one after the other. It's fine for the DIE to know what stage we're in, but it would avoid things like init and reset iteration.

I left some inline comments here and there but I definitely need to do another pass.

llvm/lib/DWARFLinkerParallel/DIEAttributeCloner.h

48

68

Let's make these Doxygen style comments as well.

llvm/lib/DWARFLinkerParallel/DWARFLinkerCompileUnit.h

26

This should be singular: i.e. Stage.

96

How about clear or reset?

262

We need the reinterpret_cast because the OutDieOffsetArray stores uint64_ts instead of std::atomic<uint64_t>. Why can't we store the latter?

[avl]

In D153268#4438509, @JDevlieghere wrote:

I don't have all of dsymutil paged in to do a really thorough/meaningful review of all the details. Even if I did I'm sure a bunch of stuff would slip through that would only be caught by real world qualification.

At a high level I think the approach makes sense. I've spent quite a bit of time thinking of alternatives and I cant't think of anything more efficient given the constraints that we have (i.e. not being able to keep all the input DWARF concurrently in memory).

As for the implementation itself:

• I like that you factored out things like the attribute cloning and I wonder if we could hoist this up and make it work with the non-parallel linker as well. I don't think we should go to extreme lengths to unify the two implementations, but even if we were to switch over to the new (parallel) implementation tomorrow, I expect the old one to be around for at least a few more years and I'd hate to have to maintain both.

yes, it would be good to have single implementation. But I do not see the simple way to do it.
Actually there are other cases using similar code. f.e.

llvm/unittests/DebugInfo/DWARF/DwarfGenerator.h
https://reviews.llvm.org/D130315 .

Thus, it would be useful if we have kind of DWARFLinkerBase library, containing general code for cloning, creating and emitting DIEs.
That library might be used by DWARFLinker, DWARFLinkerParallel, unittests for DebugInfo, BOLT.
Though, I think there are a lot of details which will make implementing that library difficult task.

Anyway, if we want to have single implementation for it then, probably, the best way would be to think of creating DWARFLinkerBase library.
That library should have base implementations for compile units, for code cloning, creating and emitting DIEs, this library should not depend on AsmPrinter.
What do you think?

• I wonder if we could make the stages more explicit. If I'm reading the code right, the data (i.e. the DIE) and the logic (i.e. the live analysis) are shared in the same class and we have to maintain state. I would prefer a design where the two are decoupled and the data moves through the different stages. The way I'm imagining this is to have a class for every stage, possibly with its own shared context, and then have the DIEs move through them one after the other. It's fine for the DIE to know what stage we're in, but it would avoid things like init and reset iteration.

If I understood correctly, it looks like the current picture is quite close to that description:

The CompileUnit contains data shared between stages and compile units know the current stage.
There is a separate class doing liveness analysys: DependencyTracker.
This class uses data keeping by CompileUnit(this data is shared context).
The result of liveness analysys is used by other stages that is why compile unit keeps the data.

We need "init" and "reset" functions as we need to erase data keeping by compile unit when we return to previous stages.
i.e. when we return to the previous stage we need to adapt shared context.
Probably instead of "init" and "reset" we need to name methods "sync shared context with the current stage" ?

llvm/lib/DWARFLinkerParallel/DWARFLinkerCompileUnit.h

262

std::atomic<> does not have copy constructor/operator. Because of this it could not be put into SmallVector.

[avl]

rebased. addressed comments.

[avl]

rebased.

[avl]

rebased.

[avl]

friendly ping.

[avl]

friendly ping.

[avl]

rebased.

[avl]

@JDevlieghere @aprantl

Does this patch require some changes?

Previous comment asks for refactoring attributes cloning. Should we create some DWARFLinkerBase library for this?

[JDevlieghere]

In D153268#4550774, @avl wrote:

@JDevlieghere @aprantl

Does this patch require some changes?

Previous comment asks for refactoring attributes cloning. Should we create some DWARFLinkerBase library for this?

No major concerns that block landing this. I still feel it would be great to unify stuff but we can do that incrementally after the patch has landed.

[avl]

Thank you for the review!

[avl]

rebased.

[avl]

rebased.

[nikic]

Reverted due to test failures on s390x, see e.g. https://lab.llvm.org/buildbot/#/builders/94/builds/16146.

llvm/include/llvm/CodeGen/DwarfStringPoolEntry.h

struct DwarfStringPoolEntry {
 
   MCSymbol *Symbol = nullptr;
   uint64_t Offset = 0;
   unsigned Index = 0;
 
   bool isIndexed() const { return Index != NotIndexed; }
 };
 
+/// DwarfStringPoolEntry with string keeping externally.
+struct DwarfStringPoolEntryWithExtString : public DwarfStringPoolEntry {
+  StringRef String;
+};
+
 /// DwarfStringPoolEntryRef: Dwarf string pool entry reference.
 ///
 /// Dwarf string pool entry keeps string value and its data.
 /// There are two variants how data are represented:
 ///
-///   1. By value - StringMapEntry<DwarfStringPoolEntry>.
-///   2. By pointer - StringMapEntry<DwarfStringPoolEntry *>.
+///   1. String data in pool  - StringMapEntry<DwarfStringPoolEntry>.
+///   2. External string data - DwarfStringPoolEntryWithExtString.
 ///
-/// The "By pointer" variant allows for reducing memory usage for the case
-/// when string pool entry does not have data: it keeps the null pointer
-/// and so no need to waste space for the full DwarfStringPoolEntry.
-/// It is recommended to use "By pointer" variant if not all entries
-/// of dwarf string pool have corresponding DwarfStringPoolEntry.
+/// The external data variant allows reducing memory usage for the case
+/// when string pool entry does not have data: string entry does not
+/// keep any data and so no need to waste space for the full
+/// DwarfStringPoolEntry. It is recommended to use external variant if not all
+/// entries of dwarf string pool have corresponding DwarfStringPoolEntry.
 
 class DwarfStringPoolEntryRef {
   /// Pointer type for "By value" string entry.
   using ByValStringEntryPtr = const StringMapEntry<DwarfStringPoolEntry> *;
 
-  /// Pointer type for "By pointer" string entry.
-  using ByPtrStringEntryPtr = const StringMapEntry<DwarfStringPoolEntry *> *;
+  /// Pointer type for external string entry.
+  using ExtStringEntryPtr = const DwarfStringPoolEntryWithExtString *;
 
   /// Pointer to the dwarf string pool Entry.
-  PointerUnion<ByValStringEntryPtr, ByPtrStringEntryPtr> MapEntry = nullptr;
+  PointerUnion<ByValStringEntryPtr, ExtStringEntryPtr> MapEntry = nullptr;
 
 public:
   DwarfStringPoolEntryRef() = default;
 
   /// ASSUMPTION: DwarfStringPoolEntryRef keeps pointer to \p Entry,
   /// thus specified entry mustn`t be reallocated.
   DwarfStringPoolEntryRef(const StringMapEntry<DwarfStringPoolEntry> &Entry)
       : MapEntry(&Entry) {}
 
   /// ASSUMPTION: DwarfStringPoolEntryRef keeps pointer to \p Entry,
   /// thus specified entry mustn`t be reallocated.
-  DwarfStringPoolEntryRef(const StringMapEntry<DwarfStringPoolEntry *> &Entry)
-      : MapEntry(&Entry) {
-    assert(cast<ByPtrStringEntryPtr>(MapEntry)->second != nullptr);
-  }
+  DwarfStringPoolEntryRef(const DwarfStringPoolEntryWithExtString &Entry)
+      : MapEntry(&Entry) {}
 
   explicit operator bool() const { return !MapEntry.isNull(); }
 
   /// \returns symbol for the dwarf string.
   MCSymbol *getSymbol() const {
     assert(getEntry().Symbol && "No symbol available!");
     return getEntry().Symbol;
   }
 
   /// \returns offset for the dwarf string.
   uint64_t getOffset() const { return getEntry().Offset; }
 
   /// \returns index for the dwarf string.
   unsigned getIndex() const {
     assert(getEntry().isIndexed() && "Index is not set!");
     return getEntry().Index;
   }
 
   /// \returns string.
   StringRef getString() const {
     if (isa<ByValStringEntryPtr>(MapEntry))
       return cast<ByValStringEntryPtr>(MapEntry)->first();
 
-    return cast<ByPtrStringEntryPtr>(MapEntry)->first();
+    return cast<ExtStringEntryPtr>(MapEntry)->String;
   }
 
   /// \returns the entire string pool entry for convenience.
   const DwarfStringPoolEntry &getEntry() const {
     if (isa<ByValStringEntryPtr>(MapEntry))
       return cast<ByValStringEntryPtr>(MapEntry)->second;
 
-    return *cast<ByPtrStringEntryPtr>(MapEntry)->second;
+    return *cast<ExtStringEntryPtr>(MapEntry);
   }
 
   bool operator==(const DwarfStringPoolEntryRef &X) const {
     return MapEntry.getOpaqueValue() == X.MapEntry.getOpaqueValue();
   }
 
   bool operator!=(const DwarfStringPoolEntryRef &X) const {
     return MapEntry.getOpaqueValue() != X.MapEntry.getOpaqueValue();
   }
 };
 
 } // end namespace llvm
 
 #endif

llvm/include/llvm/DWARFLinker/DWARFLinker.h

 
 class DwarfStreamer;
 using UnitListTy = std::vector<std::unique_ptr<CompileUnit>>;
 
 /// This class represents DWARF information for source file
 /// and its address map.
 class DWARFFile {
 public:
+  using UnloadCallbackTy = std::function<void(StringRef FileName)>;
   DWARFFile(StringRef Name, std::unique_ptr<DWARFContext> Dwarf,
             std::unique_ptr<AddressesMap> Addresses,
-            const std::vector<std::string> &Warnings)
+            const std::vector<std::string> &Warnings,
+            UnloadCallbackTy = nullptr)
       : FileName(Name), Dwarf(std::move(Dwarf)),
         Addresses(std::move(Addresses)), Warnings(Warnings) {}
 
   /// The object file name.
   StringRef FileName;
 
   /// The source DWARF information.
   std::unique_ptr<DWARFContext> Dwarf;

llvm/include/llvm/DWARFLinkerParallel/AddressesMap.h

 //===- AddressesMap.h -------------------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_DWARFLINKERPARALLEL_ADDRESSESMAP_H
 #define LLVM_DWARFLINKERPARALLEL_ADDRESSESMAP_H
 
 #include "llvm/ADT/AddressRanges.h"
+#include "llvm/DebugInfo/DWARF/DWARFContext.h"
 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
 #include "llvm/DebugInfo/DWARF/DWARFExpression.h"
+#include "llvm/DebugInfo/DWARF/DWARFUnit.h"
 #include <cstdint>
 
 namespace llvm {
 namespace dwarflinker_parallel {
 
 /// Mapped value in the address map is the offset to apply to the
 /// linked address.
 using RangesTy = AddressRangesMap;
public:
   /// account that Data is at \p BaseOffset in the .debug_info section.
   ///
   /// \returns true whether any reloc has been applied.
   virtual bool applyValidRelocs(MutableArrayRef<char> Data, uint64_t BaseOffset,
                                 bool IsLittleEndian) = 0;
 
   /// Erases all data.
   virtual void clear() = 0;
+
+  /// This function checks whether variable has DWARF expression containing
+  /// operation referencing live address(f.e. DW_OP_addr, DW_OP_addrx...).
+  /// \returns first is true if the expression has an operation referencing an
+  /// address.
+  ///          second is the relocation adjustment value if the live address is
+  ///          referenced.
+  std::pair<bool, std::optional<int64_t>>
+  getVariableRelocAdjustment(const DWARFDie &DIE) {
+    assert((DIE.getTag() == dwarf::DW_TAG_variable ||
+            DIE.getTag() == dwarf::DW_TAG_constant) &&
+           "Wrong type of input die");
+
+    const auto *Abbrev = DIE.getAbbreviationDeclarationPtr();
+
+    // Check if DIE has DW_AT_location attribute.
+    DWARFUnit *U = DIE.getDwarfUnit();
+    std::optional<uint32_t> LocationIdx =
+        Abbrev->findAttributeIndex(dwarf::DW_AT_location);
+    if (!LocationIdx)
+      return std::make_pair(false, std::nullopt);
+
+    // Get offset to the DW_AT_location attribute.
+    uint64_t AttrOffset =
+        Abbrev->getAttributeOffsetFromIndex(*LocationIdx, DIE.getOffset(), *U);
+
+    // Get value of the DW_AT_location attribute.
+    std::optional<DWARFFormValue> LocationValue =
+        Abbrev->getAttributeValueFromOffset(*LocationIdx, AttrOffset, *U);
+    if (!LocationValue)
+      return std::make_pair(false, std::nullopt);
+
+    // Check that DW_AT_location attribute is of 'exprloc' class.
+    // Handling value of location expressions for attributes of 'loclist'
+    // class is not implemented yet.
+    std::optional<ArrayRef<uint8_t>> Expr = LocationValue->getAsBlock();
+    if (!Expr)
+      return std::make_pair(false, std::nullopt);
+
+    // Parse 'exprloc' expression.
+    DataExtractor Data(toStringRef(*Expr), U->getContext().isLittleEndian(),
+                       U->getAddressByteSize());
+    DWARFExpression Expression(Data, U->getAddressByteSize(),
+                               U->getFormParams().Format);
+
+    bool HasLocationAddress = false;
+    uint64_t CurExprOffset = 0;
+    for (DWARFExpression::iterator It = Expression.begin();
+         It != Expression.end(); ++It) {
+      DWARFExpression::iterator NextIt = It;
+      ++NextIt;
+
+      const DWARFExpression::Operation &Op = *It;
+      switch (Op.getCode()) {
+      case dwarf::DW_OP_const2u:
+      case dwarf::DW_OP_const4u:
+      case dwarf::DW_OP_const8u:
+      case dwarf::DW_OP_const2s:
+      case dwarf::DW_OP_const4s:
+      case dwarf::DW_OP_const8s:
+        if (NextIt == Expression.end() || !isTlsAddressCode(NextIt->getCode()))
+          break;
+        [[fallthrough]];
+      case dwarf::DW_OP_addr: {
+        HasLocationAddress = true;
+        // Check relocation for the address.
+        if (std::optional<int64_t> RelocAdjustment =
+                getExprOpAddressRelocAdjustment(*U, Op,
+                                                AttrOffset + CurExprOffset,
+                                                AttrOffset + Op.getEndOffset()))
+          return std::make_pair(HasLocationAddress, *RelocAdjustment);
+      } break;
+      case dwarf::DW_OP_constx:
+      case dwarf::DW_OP_addrx: {
+        HasLocationAddress = true;
+        if (std::optional<uint64_t> AddressOffset =
+                DIE.getDwarfUnit()->getIndexedAddressOffset(
+                    Op.getRawOperand(0))) {
+          // Check relocation for the address.
+          if (std::optional<int64_t> RelocAdjustment =
+                  getExprOpAddressRelocAdjustment(
+                      *U, Op, *AddressOffset,
+                      *AddressOffset +
+                          DIE.getDwarfUnit()->getAddressByteSize()))
+            return std::make_pair(HasLocationAddress, *RelocAdjustment);
+        }
+      } break;
+      default: {
+        // Nothing to do.
+      } break;
+      }
+      CurExprOffset = Op.getEndOffset();
+    }
+
+    return std::make_pair(HasLocationAddress, std::nullopt);
+  }
+
+protected:
+  inline bool isTlsAddressCode(uint8_t DW_OP_Code) {
+    return DW_OP_Code == dwarf::DW_OP_form_tls_address ||
+           DW_OP_Code == dwarf::DW_OP_GNU_push_tls_address;
+  }
 };
 
 } // end of namespace dwarflinker_parallel
 } // end namespace llvm
 
 #endif // LLVM_DWARFLINKERPARALLEL_ADDRESSESMAP_H

llvm/include/llvm/DWARFLinkerParallel/DWARFFile.h

 /// May be used asynchroniously for reading.
 class DWARFFile {
 public:
   using UnloadCallbackTy = std::function<void(StringRef FileName)>;
 
   DWARFFile(StringRef Name, std::unique_ptr<DWARFContext> Dwarf,
             std::unique_ptr<AddressesMap> Addresses,
             const std::vector<std::string> &Warnings,
-            UnloadCallbackTy UnloadFunc = nullptr)
-      : FileName(Name), Dwarf(std::move(Dwarf)),
-        Addresses(std::move(Addresses)), Warnings(Warnings),
-        UnloadFunc(UnloadFunc) {
-    if (this->Dwarf)
-      Endianess = this->Dwarf->isLittleEndian() ? support::endianness::little
-                                                : support::endianness::big;
-  }
+            UnloadCallbackTy UnloadFunc = nullptr);
 
   /// Object file name.
   StringRef FileName;
 
   /// Source DWARF information.
   std::unique_ptr<DWARFContext> Dwarf;
 
   /// Helpful address information(list of valid address ranges, relocations).
   std::unique_ptr<AddressesMap> Addresses;
 
   /// Warnings for object file.
   const std::vector<std::string> &Warnings;
 
-  /// Endiannes of source DWARF information.
-  support::endianness Endianess = support::endianness::little;
-
   /// Callback to the module keeping object file to unload.
   UnloadCallbackTy UnloadFunc;
 
   /// Unloads object file and corresponding AddressesMap and Dwarf Context.
   void unload() {
     Addresses.reset();
     Dwarf.reset();
 

llvm/include/llvm/DWARFLinkerParallel/StringPool.h

 #include <string>
 #include <string_view>
 
 namespace llvm {
 namespace dwarflinker_parallel {
 
 /// StringEntry keeps data of the string: the length, external offset
 /// and a string body which is placed right after StringEntry.
-using StringEntry = StringMapEntry<DwarfStringPoolEntry *>;
+using StringEntry = StringMapEntry<std::nullopt_t>;
 
 class StringPoolEntryInfo {
 public:
   /// \returns Hash value for the specified \p Key.
   static inline uint64_t getHashValue(const StringRef &Key) {
     return xxh3_64bits(Key);
   }
 

llvm/include/llvm/DWARFLinkerParallel/StringTable.h

-//===- StringTable.h --------------------------------------------*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_DWARFLINKERPARALLEL_STRINGTABLE_H
-#define LLVM_DWARFLINKERPARALLEL_STRINGTABLE_H
-
-#include "llvm/ADT/SmallVector.h"
-#include "llvm/DWARFLinkerParallel/StringPool.h"
-
-namespace llvm {
-namespace dwarflinker_parallel {
-
-using StringsVector = SmallVector<StringEntry *>;
-
-/// This class prepares strings for emission into .debug_str table:
-/// translates string if necessary, assigns index and offset, keeps in order.
-class StringTable {
-public:
-  StringTable(StringPool &Strings,
-              std::function<StringRef(StringRef)> StringsTranslator)
-      : Strings(Strings), StringsTranslator(StringsTranslator) {}
-  ~StringTable() {}
-
-  /// Add string to the vector of strings which should be emitted.
-  /// Translate input string if neccessary, assign index and offset.
-  /// \returns updated string entry.
-  StringEntry *add(StringEntry *String) {
-    // Translate string if necessary.
-    if (StringsTranslator)
-      String = Strings.insert(StringsTranslator(String->first())).first;
-
-    // Store String for emission and assign index and offset.
-    if (String->getValue() == nullptr) {
-      DwarfStringPoolEntry *NewEntry =
-          Strings.getAllocatorRef().Allocate<DwarfStringPoolEntry>();
-
-      NewEntry->Symbol = nullptr;
-      NewEntry->Index = StringEntriesForEmission.size();
-
-      if (StringEntriesForEmission.empty())
-        NewEntry->Offset = 0;
-      else {
-        StringEntry *PrevString = StringEntriesForEmission.back();
-        NewEntry->Offset =
-            PrevString->getValue()->Offset + PrevString->getKeyLength() + 1;
-      }
-
-      String->getValue() = NewEntry;
-      StringEntriesForEmission.push_back(String);
-    }
-
-    return String;
-  }
-
-  /// Erase contents of StringsForEmission.
-  void clear() { StringEntriesForEmission.clear(); }
-
-  /// Enumerate all strings in sequential order and call \p Handler for each
-  /// string.
-  void forEach(function_ref<void(DwarfStringPoolEntryRef)> Handler) const {
-    for (const StringEntry *Entry : StringEntriesForEmission)
-      Handler(*Entry);
-  }
-
-  std::function<StringRef(StringRef)> getTranslator() {
-    return StringsTranslator;
-  }
-
-protected:
-  /// List of strings for emission.
-  StringsVector StringEntriesForEmission;
-
-  /// String pool for the translated strings.
-  StringPool &Strings;
-
-  /// Translator for the strings.
-  std::function<StringRef(StringRef)> StringsTranslator;
-};
-
-} // end of namespace dwarflinker_parallel
-} // end namespace llvm
-
-#endif // LLVM_DWARFLINKERPARALLEL_STRINGTABLE_H

llvm/include/llvm/DebugInfo/DWARF/DWARFDebugMacro.h

 
 namespace llvm {
 
 class raw_ostream;
 class DwarfStreamer;
 
 class DWARFDebugMacro {
   friend DwarfStreamer;
+  friend dwarflinker_parallel::CompileUnit;
 
   /// DWARFv5 section 6.3.1 Macro Information Header.
   enum HeaderFlagMask {
 #define HANDLE_MACRO_FLAG(ID, NAME) MACRO_##NAME = ID,
 #include "llvm/BinaryFormat/Dwarf.def"
   };
   struct MacroHeader {
     /// Macro version information number.

llvm/lib/DWARFLinker/DWARFLinker.cpp

DWARFLinker::getVariableRelocAdjustment(AddressesMap &RelocMgr,
   uint64_t CurExprOffset = 0;
   for (DWARFExpression::iterator It = Expression.begin();
        It != Expression.end(); ++It) {
     DWARFExpression::iterator NextIt = It;
     ++NextIt;
 
     const DWARFExpression::Operation &Op = *It;
     switch (Op.getCode()) {
+    case dwarf::DW_OP_const2u:
     case dwarf::DW_OP_const4u:
     case dwarf::DW_OP_const8u:
+    case dwarf::DW_OP_const2s:
     case dwarf::DW_OP_const4s:
     case dwarf::DW_OP_const8s:
       if (NextIt == Expression.end() || !isTlsAddressCode(NextIt->getCode()))
         break;
       [[fallthrough]];
     case dwarf::DW_OP_addr: {
       HasLocationAddress = true;
       // Check relocation for the address.

llvm/lib/DWARFLinker/DWARFLinkerCompileUnit.cpp

if (auto ExprLockBlock = Value->getAsBlock()) {
                                  U->getFormParams().Format);
 
       for (DWARFExpression::iterator It = Expression.begin();
            (It != Expression.end()) && !I.InDebugMap; ++It) {
         DWARFExpression::iterator NextIt = It;
         ++NextIt;
 
         switch (It->getCode()) {
+        case dwarf::DW_OP_const2u:
         case dwarf::DW_OP_const4u:
         case dwarf::DW_OP_const8u:
+        case dwarf::DW_OP_const2s:
         case dwarf::DW_OP_const4s:
         case dwarf::DW_OP_const8s:
           if (NextIt == Expression.end() ||
               NextIt->getCode() != dwarf::DW_OP_form_tls_address)
             break;
           [[fallthrough]];
         case dwarf::DW_OP_constx:
         case dwarf::DW_OP_addr:

llvm/lib/DWARFLinkerParallel/ArrayList.h

+//===- ArrayList.h ----------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_DWARFLINKERPARALLEL_ARRAYLIST_H
+#define LLVM_LIB_DWARFLINKERPARALLEL_ARRAYLIST_H
+
+#include "DWARFLinkerGlobalData.h"
+#include "llvm/Support/PerThreadBumpPtrAllocator.h"
+
+namespace llvm {
+namespace dwarflinker_parallel {
+
+/// This class is a simple list of T structures. It keeps elements as
+/// pre-allocated groups to save memory for each element's next pointer.
+/// It allocates internal data using specified per-thread BumpPtrAllocator.
+template <typename T, size_t ItemsGroupSize = 512> class ArrayList {
+public:
+  /// Copy specified \p Item into the list.
+  T &noteItem(const T &Item) {
+    assert(Allocator != nullptr);
+
+    ItemsGroup *CurGroup = LastGroup;
+
+    if (CurGroup == nullptr) {
+      // Allocate first ItemsGroup.
+      LastGroup = Allocator->Allocate<ItemsGroup>();
+      LastGroup->ItemsCount = 0;
+      LastGroup->Next = nullptr;
+      GroupsHead = LastGroup;
+      CurGroup = LastGroup;
+    }
+
+    if (CurGroup->ItemsCount == ItemsGroupSize) {
+      // Allocate next ItemsGroup if current one is full.
+      LastGroup = Allocator->Allocate<ItemsGroup>();
+      LastGroup->ItemsCount = 0;
+      LastGroup->Next = nullptr;
+      CurGroup->Next = LastGroup;
+      CurGroup = LastGroup;
+    }
+
+    // Copy item into the next position inside current ItemsGroup.
+    CurGroup->Items[CurGroup->ItemsCount] = Item;
+    return CurGroup->Items[CurGroup->ItemsCount++];
+  }
+
+  using ItemHandlerTy = function_ref<void(T &)>;
+
+  /// Enumerate all items and apply specified \p Handler to each.
+  void forEach(ItemHandlerTy Handler) {
+    for (ItemsGroup *CurGroup = GroupsHead; CurGroup != nullptr;
+         CurGroup = CurGroup->Next) {
+      for (size_t Idx = 0; Idx < CurGroup->ItemsCount; Idx++) {
+        Handler(CurGroup->Items[Idx]);
+      }
+    }
+  }
+
+  /// Check whether list is empty.
+  bool empty() { return GroupsHead == nullptr; }
+
+  /// Erase list.
+  void erase() {
+    GroupsHead = nullptr;
+    LastGroup = nullptr;
+  }
+
+  void setAllocator(parallel::PerThreadBumpPtrAllocator *Allocator) {
+    this->Allocator = Allocator;
+  }
+
+protected:
+  struct ItemsGroup {
+    std::array<T, ItemsGroupSize> Items;
+    ItemsGroup *Next = nullptr;
+    size_t ItemsCount = 0;
+  };
+
+  ItemsGroup *GroupsHead = nullptr;
+  ItemsGroup *LastGroup = nullptr;
+  parallel::PerThreadBumpPtrAllocator *Allocator = nullptr;
+};
+
+} // end of namespace dwarflinker_parallel
+} // end namespace llvm
+
+#endif // LLVM_LIB_DWARFLINKERPARALLEL_ARRAYLIST_H

llvm/lib/DWARFLinkerParallel/CMakeLists.txt

 add_llvm_component_library(LLVMDWARFLinkerParallel
+  DependencyTracker.cpp
+  DIEAttributeCloner.cpp
   DWARFEmitterImpl.cpp
+  DWARFFile.cpp
   DWARFLinker.cpp
+  DWARFLinkerCompileUnit.cpp
   DWARFLinkerImpl.cpp
+  DWARFLinkerUnit.cpp
   OutputSections.cpp
   StringPool.cpp
 
   ADDITIONAL_HEADER_DIRS
   ${LLVM_MAIN_INCLUDE_DIR}/llvm/DWARFLinkerParallel
 
   DEPENDS
   intrinsics_gen

llvm/lib/DWARFLinkerParallel/DIEAttributeCloner.h

+//===- DIEAttributeCloner.h -------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_DWARFLINKERPARALLEL_DIEATTRIBUTECLONER_H
+#define LLVM_LIB_DWARFLINKERPARALLEL_DIEATTRIBUTECLONER_H
+
+#include "ArrayList.h"
+#include "DIEGenerator.h"
+#include "DWARFLinkerCompileUnit.h"
+#include "DWARFLinkerGlobalData.h"
+
+namespace llvm {
+namespace dwarflinker_parallel {
+
+/// This class creates clones of input DIE attributes.
+/// It enumerates attributes of input DIE, creates clone for each
+/// attribute, adds cloned attribute to the output DIE.
+class DIEAttributeCloner {
+public:
+  DIEAttributeCloner(DIE *OutDIE, CompileUnit &CU,
+                     const DWARFDebugInfoEntry *InputDieEntry,
+                     DIEGenerator &Generator,
+                     std::optional<int64_t> FuncAddressAdjustment,
+                     std::optional<int64_t> VarAddressAdjustment,
+                     bool HasLocationExpressionAddress)
+      : OutDIE(OutDIE), CU(CU), DebugInfoOutputSection(CU.getSectionDescriptor(
+                                    DebugSectionKind::DebugInfo)),
+        InputDieEntry(InputDieEntry), Generator(Generator),
+        FuncAddressAdjustment(FuncAddressAdjustment),
+        VarAddressAdjustment(VarAddressAdjustment),
+        HasLocationExpressionAddress(HasLocationExpressionAddress) {
+    InputDIEIdx = CU.getDIEIndex(InputDieEntry);
+  }
+
+  /// Clone attributes of input DIE.
+  void clone();
+
+  /// Create abbreviations for the output DIE after all attributes are cloned.
+  unsigned finalizeAbbreviations(bool HasChildrenToClone);
+
+  /// Information gathered and exchanged between the various
+  /// clone*Attr helpers about the attributes of a particular DIE.
+  ///
+  /// Cannot be used concurrently.
+  struct AttributesInfo {
+    /// Names.
+    StringEntry *Name = nullptr;
+    StringEntry *MangledName = nullptr;
+    StringEntry *NameWithoutTemplate = nullptr;
+
+    /// Does the DIE have a low_pc attribute?
+    bool HasLowPc = false;
+
+    /// Is this DIE only a declaration?
+    bool IsDeclaration = false;
+
+    /// Does the DIE have a ranges attribute?
+    bool HasRanges = false;
+  };
+
+  AttributesInfo AttrInfo;
+
+protected:
+  /// Clone string attribute.
+  size_t
+  cloneStringAttr(const DWARFFormValue &Val,
+                  const DWARFAbbreviationDeclaration::AttributeSpec &AttrSpec);
+
+  /// Clone attribute referencing another DIE.
+  size_t
+  cloneDieRefAttr(const DWARFFormValue &Val,
+                  const DWARFAbbreviationDeclaration::AttributeSpec &AttrSpec);
+
+  /// Clone scalar attribute.
+  size_t
+  cloneScalarAttr(const DWARFFormValue &Val,
+                  const DWARFAbbreviationDeclaration::AttributeSpec &AttrSpec);
+
+  /// Clone block or exprloc attribute.
+  size_t
+  cloneBlockAttr(const DWARFFormValue &Val,
+                 const DWARFAbbreviationDeclaration::AttributeSpec &AttrSpec);
+
+  /// Clone address attribute.
+  size_t
+  cloneAddressAttr(const DWARFFormValue &Val,
+                   const DWARFAbbreviationDeclaration::AttributeSpec &AttrSpec);
+
+  /// Returns true if attribute should be skipped.
+  bool
+  shouldSkipAttribute(DWARFAbbreviationDeclaration::AttributeSpec AttrSpec);
+
+  /// Update patches offsets with the size of abbreviation number.
+  void
+  updatePatchesWithSizeOfAbbreviationNumber(unsigned SizeOfAbbreviationNumber) {
+    for (uint64_t *OffsetPtr : PatchesOffsets)
+      *OffsetPtr += SizeOfAbbreviationNumber;
+  }
+
+  /// Output DIE.
+  DIE *OutDIE = nullptr;
+
+  /// Compile unit for the output DIE.
+  CompileUnit &CU;
+
+  /// .debug_info section descriptor.
+  SectionDescriptor &DebugInfoOutputSection;
+
+  /// Input DIE entry.
+  const DWARFDebugInfoEntry *InputDieEntry = nullptr;
+
+  /// Input DIE index.
+  uint32_t InputDIEIdx = 0;
+
+  /// Output DIE generator.
+  DIEGenerator &Generator;
+
+  /// Relocation adjustment for the function address ranges.
+  std::optional<int64_t> FuncAddressAdjustment;
+
+  /// Relocation adjustment for the variable locations.
+  std::optional<int64_t> VarAddressAdjustment;
+
+  /// Indicates whether InputDieEntry has an location attribute
+  /// containg address expression.
+  bool HasLocationExpressionAddress = false;
+
+  /// Output offset after all attributes.
+  unsigned AttrOutOffset = 0;
+
+  /// Patches for the cloned attributes.
+  OffsetsPtrVector PatchesOffsets;
+};
+
+} // end of namespace dwarflinker_parallel
+} // end namespace llvm
+
+#endif // LLVM_LIB_DWARFLINKERPARALLEL_DIEATTRIBUTECLONER_H

llvm/lib/DWARFLinkerParallel/DIEAttributeCloner.cpp

+//=== DIEAttributeCloner.cpp ----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "DIEAttributeCloner.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
+
+namespace llvm {
+namespace dwarflinker_parallel {
+
+void DIEAttributeCloner::clone() {
+  DWARFUnit &U = CU.getOrigUnit();
+
+  // Extract and clone every attribute.
+  DWARFDataExtractor Data = U.getDebugInfoExtractor();
+
+  uint64_t Offset = InputDieEntry->getOffset();
+  // Point to the next DIE (generally there is always at least a NULL
+  // entry after the current one). If this is a lone
+  // DW_TAG_compile_unit without any children, point to the next unit.
+  uint64_t NextOffset = (InputDIEIdx + 1 < U.getNumDIEs())
+                            ? U.getDIEAtIndex(InputDIEIdx + 1).getOffset()
+                            : U.getNextUnitOffset();
+
+  // We could copy the data only if we need to apply a relocation to it. After
+  // testing, it seems there is no performance downside to doing the copy
+  // unconditionally, and it makes the code simpler.
+  SmallString<40> DIECopy(Data.getData().substr(Offset, NextOffset - Offset));
+  Data =
+      DWARFDataExtractor(DIECopy, Data.isLittleEndian(), Data.getAddressSize());
+
+  // Modify the copy with relocated addresses.
+  CU.getContaingFile().Addresses->applyValidRelocs(DIECopy, Offset,
+                                                   Data.isLittleEndian());
+
+  // Reset the Offset to 0 as we will be working on the local copy of
+  // the data.
+  Offset = 0;
+
+  const auto *Abbrev = InputDieEntry->getAbbreviationDeclarationPtr();
+  Offset += getULEB128Size(Abbrev->getCode());
+
+  // Set current output offset.
+  AttrOutOffset = OutDIE->getOffset();
+  for (const auto &AttrSpec : Abbrev->attributes()) {
+    // Check whether current attribute should be skipped.
+    if (shouldSkipAttribute(AttrSpec)) {
+      DWARFFormValue::skipValue(AttrSpec.Form, Data, &Offset,
+                                U.getFormParams());
+      continue;
+    }
+
+    // Note patches for attributes referencing other sections.
+    switch (AttrSpec.Attr) {
+    case dwarf::DW_AT_stmt_list: {
+      DebugInfoOutputSection.notePatchWithOffsetUpdate(
+          DebugOffsetPatch{AttrOutOffset, &CU.getSectionDescriptor(
+                                              DebugSectionKind::DebugLine)},
+          PatchesOffsets);
+    } break;
+    case dwarf::DW_AT_macros: {
+      DebugInfoOutputSection.notePatchWithOffsetUpdate(
+          DebugOffsetPatch{AttrOutOffset, &CU.getSectionDescriptor(
+                                              DebugSectionKind::DebugMacro)},
+          PatchesOffsets);
+    } break;
+    case dwarf::DW_AT_macro_info: {
+      DebugInfoOutputSection.notePatchWithOffsetUpdate(
+          DebugOffsetPatch{AttrOutOffset, &CU.getSectionDescriptor(
+                                              DebugSectionKind::DebugMacinfo)},
+          PatchesOffsets);
+    } break;
+    default: {
+    } break;
+    }
+
+    DWARFFormValue Val = AttrSpec.getFormValue();
+    Val.extractValue(Data, &Offset, U.getFormParams(), &U);
+
+    // Clone current attribute.
+    switch (AttrSpec.Form) {
+    case dwarf::DW_FORM_strp:
+    case dwarf::DW_FORM_line_strp:
+    case dwarf::DW_FORM_string:
+    case dwarf::DW_FORM_strx:
+    case dwarf::DW_FORM_strx1:
+    case dwarf::DW_FORM_strx2:
+    case dwarf::DW_FORM_strx3:
+    case dwarf::DW_FORM_strx4:
+      AttrOutOffset += cloneStringAttr(Val, AttrSpec);
+      break;
+    case dwarf::DW_FORM_ref_addr:
+    case dwarf::DW_FORM_ref1:
+    case dwarf::DW_FORM_ref2:
+    case dwarf::DW_FORM_ref4:
+    case dwarf::DW_FORM_ref8:
+    case dwarf::DW_FORM_ref_udata:
+      AttrOutOffset += cloneDieRefAttr(Val, AttrSpec);
+      break;
+    case dwarf::DW_FORM_data1:
+    case dwarf::DW_FORM_data2:
+    case dwarf::DW_FORM_data4:
+    case dwarf::DW_FORM_data8:
+    case dwarf::DW_FORM_udata:
+    case dwarf::DW_FORM_sdata:
+    case dwarf::DW_FORM_sec_offset:
+    case dwarf::DW_FORM_flag:
+    case dwarf::DW_FORM_flag_present:
+    case dwarf::DW_FORM_rnglistx:
+    case dwarf::DW_FORM_loclistx:
+    case dwarf::DW_FORM_implicit_const:
+      AttrOutOffset += cloneScalarAttr(Val, AttrSpec);
+      break;
+    case dwarf::DW_FORM_block:
+    case dwarf::DW_FORM_block1:
+    case dwarf::DW_FORM_block2:
+    case dwarf::DW_FORM_block4:
+    case dwarf::DW_FORM_exprloc:
+      AttrOutOffset += cloneBlockAttr(Val, AttrSpec);
+      break;
+    case dwarf::DW_FORM_addr:
+    case dwarf::DW_FORM_addrx:
+    case dwarf::DW_FORM_addrx1:
+    case dwarf::DW_FORM_addrx2:
+    case dwarf::DW_FORM_addrx3:
+    case dwarf::DW_FORM_addrx4:
+      AttrOutOffset += cloneAddressAttr(Val, AttrSpec);
+      break;
+    default:
+      CU.warn("unsupported attribute form " +
+                  dwarf::FormEncodingString(AttrSpec.Form) +
+                  " in DieAttributeCloner::clone(). Dropping.",
+              InputDieEntry);
+    }
+  }
+}
+
+bool DIEAttributeCloner::shouldSkipAttribute(
+    DWARFAbbreviationDeclaration::AttributeSpec AttrSpec) {
+  switch (AttrSpec.Attr) {
+  default:
+    return false;
+  case dwarf::DW_AT_low_pc:
+  case dwarf::DW_AT_high_pc:
+  case dwarf::DW_AT_ranges:
+    if (CU.getGlobalData().getOptions().UpdateIndexTablesOnly)
+      return false;
+
+    // Skip address attribute if we are in function scope and function does not
+    // reference live address.
+    return CU.getDIEInfo(InputDIEIdx).getIsInFunctionScope() &&
+           !FuncAddressAdjustment.has_value();
+  case dwarf::DW_AT_rnglists_base:
+    // In case !Update the .debug_addr table is not generated/preserved.
+    // Thus instead of DW_FORM_rnglistx the DW_FORM_sec_offset is used.
+    // Since DW_AT_rnglists_base is used for only DW_FORM_rnglistx the
+    // DW_AT_rnglists_base is removed.
+    return !CU.getGlobalData().getOptions().UpdateIndexTablesOnly;
+  case dwarf::DW_AT_str_offsets_base:
+    // DWARFLinker does not generate or keep .debug_str_offsets table.
+    return true;
+  case dwarf::DW_AT_loclists_base:
+    // In case !Update the .debug_addr table is not generated/preserved.
+    // Thus instead of DW_FORM_loclistx the DW_FORM_sec_offset is used.
+    // Since DW_AT_loclists_base is used for only DW_FORM_loclistx the
+    // DW_AT_loclists_base is removed.
+    return !CU.getGlobalData().getOptions().UpdateIndexTablesOnly;
+  case dwarf::DW_AT_location:
+  case dwarf::DW_AT_frame_base:
+    if (CU.getGlobalData().getOptions().UpdateIndexTablesOnly)
+      return false;
+
+    // When location expression contains an address: skip this attribute
+    // if it does not reference live address.
+    if (HasLocationExpressionAddress)
+      return !VarAddressAdjustment.has_value();
+
+    // Skip location attribute if we are in function scope and function does not
+    // reference live address.
+    return CU.getDIEInfo(InputDIEIdx).getIsInFunctionScope() &&
+           !FuncAddressAdjustment.has_value();
+  }
+}
+
+size_t DIEAttributeCloner::cloneStringAttr(
+    const DWARFFormValue &Val,
+    const DWARFAbbreviationDeclaration::AttributeSpec &AttrSpec) {
+  std::optional<const char *> String = dwarf::toString(Val);
+  if (!String) {
+    CU.warn("cann't read string attribute.");
+    return 0;
+  }
+
+  StringEntry *StringInPool =
+      CU.getGlobalData().getStringPool().insert(*String).first;
+  if (AttrSpec.Form == dwarf::DW_FORM_line_strp) {
+    DebugInfoOutputSection.notePatchWithOffsetUpdate(
+        DebugLineStrPatch{{AttrOutOffset}, StringInPool}, PatchesOffsets);
+    return Generator
+        .addStringPlaceholderAttribute(AttrSpec.Attr, dwarf::DW_FORM_line_strp)
+        .second;
+  }
+
+  DebugInfoOutputSection.notePatchWithOffsetUpdate(
+      DebugStrPatch{{AttrOutOffset}, StringInPool}, PatchesOffsets);
+
+  // Update attributes info.
+  if (AttrSpec.Attr == dwarf::DW_AT_name)
+    AttrInfo.Name = StringInPool;
+  else if (AttrSpec.Attr == dwarf::DW_AT_MIPS_linkage_name ||
+           AttrSpec.Attr == dwarf::DW_AT_linkage_name)
+    AttrInfo.MangledName = StringInPool;
+
+  return Generator
+      .addStringPlaceholderAttribute(AttrSpec.Attr, dwarf::DW_FORM_strp)
+      .second;
+}
+
+size_t DIEAttributeCloner::cloneDieRefAttr(
+    const DWARFFormValue &Val,
+    const DWARFAbbreviationDeclaration::AttributeSpec &AttrSpec) {
+  if (AttrSpec.Attr == dwarf::DW_AT_sibling)
+    return 0;
+
+  std::optional<std::pair<CompileUnit *, uint32_t>> RefDiePair =
+      CU.resolveDIEReference(Val);
+  if (!RefDiePair) {
+    // If the referenced DIE is not found,  drop the attribute.
+    CU.warn("cann't find referenced DIE.", InputDieEntry);
+    return 0;
+  }
+  assert(RefDiePair->first->getStage() >= CompileUnit::Stage::Loaded);
+  assert(RefDiePair->second != 0);
+
+  // Get output offset for referenced DIE.
+  uint64_t OutDieOffset =
+      RefDiePair->first->getDieOutOffset(RefDiePair->second);
+
+  // Examine whether referenced DIE is in current compile unit.
+  bool IsLocal = CU.getUniqueID() == RefDiePair->first->getUniqueID();
+
+  // Set attribute form basing on the kind of referenced DIE(local or not?).
+  dwarf::Form NewForm = IsLocal ? dwarf::DW_FORM_ref4 : dwarf::DW_FORM_ref_addr;
+
+  // Check whether current attribute references already cloned DIE inside
+  // the same compilation unit. If true - write the already known offset value.
+  if (IsLocal && (OutDieOffset != 0))
+    return Generator.addScalarAttribute(AttrSpec.Attr, NewForm, OutDieOffset)
+        .second;
+
+  // If offset value is not known at this point then create patch for the
+  // reference value and write dummy value into the attribute.
+  DebugInfoOutputSection.notePatchWithOffsetUpdate(
+      DebugDieRefPatch{AttrOutOffset, &CU, RefDiePair->first,
+                       RefDiePair->second},
+      PatchesOffsets);
+  return Generator.addScalarAttribute(AttrSpec.Attr, NewForm, 0xBADDEF).second;
+}
+
+size_t DIEAttributeCloner::cloneScalarAttr(
+    const DWARFFormValue &Val,
+    const DWARFAbbreviationDeclaration::AttributeSpec &AttrSpec) {
+  uint64_t Value;
+  // Check for the offset to the macro table. If offset is incorrect then we
+  // need to remove the attribute.
+  if (AttrSpec.Attr == dwarf::DW_AT_macro_info) {
+    if (std::optional<uint64_t> Offset = Val.getAsSectionOffset()) {
+      const DWARFDebugMacro *Macro =
+          CU.getContaingFile().Dwarf->getDebugMacinfo();
+      if (Macro == nullptr || !Macro->hasEntryForOffset(*Offset))
+        return 0;
+    }
+  }
+
+  if (AttrSpec.Attr == dwarf::DW_AT_macros) {
+    if (std::optional<uint64_t> Offset = Val.getAsSectionOffset()) {
+      const DWARFDebugMacro *Macro =
+          CU.getContaingFile().Dwarf->getDebugMacro();
+      if (Macro == nullptr || !Macro->hasEntryForOffset(*Offset))
+        return 0;
+    }
+  }
+
+  if (CU.getGlobalData().getOptions().UpdateIndexTablesOnly) {
+    if (auto OptionalValue = Val.getAsUnsignedConstant())
+      Value = *OptionalValue;
+    else if (auto OptionalValue = Val.getAsSignedConstant())
+      Value = *OptionalValue;
+    else if (auto OptionalValue = Val.getAsSectionOffset())
+      Value = *OptionalValue;
+    else {
+      CU.warn("unsupported scalar attribute form. Dropping attribute.",
+              InputDieEntry);
+      return 0;
+    }
+
+    if (AttrSpec.Attr == dwarf::DW_AT_declaration && Value)
+      AttrInfo.IsDeclaration = true;
+
+    if (AttrSpec.Form == dwarf::DW_FORM_loclistx)
+      return Generator.addLocListAttribute(AttrSpec.Attr, AttrSpec.Form, Value)
+          .second;
+
+    return Generator.addScalarAttribute(AttrSpec.Attr, AttrSpec.Form, Value)
+        .second;
+  }
+
+  dwarf::Form ResultingForm = AttrSpec.Form;
+  if (AttrSpec.Form == dwarf::DW_FORM_rnglistx) {
+    // DWARFLinker does not generate .debug_addr table. Thus we need to change
+    // all "addrx" related forms to "addr" version. Change DW_FORM_rnglistx
+    // to DW_FORM_sec_offset here.
+    std::optional<uint64_t> Index = Val.getAsSectionOffset();
+    if (!Index) {
+      CU.warn("cann't read the attribute. Dropping.", InputDieEntry);
+      return 0;
+    }
+    std::optional<uint64_t> Offset = CU.getOrigUnit().getRnglistOffset(*Index);
+    if (!Offset) {
+      CU.warn("cann't read the attribute. Dropping.", InputDieEntry);
+      return 0;
+    }
+
+    Value = *Offset;
+    ResultingForm = dwarf::DW_FORM_sec_offset;
+  } else if (AttrSpec.Form == dwarf::DW_FORM_loclistx) {
+    // DWARFLinker does not generate .debug_addr table. Thus we need to change
+    // all "addrx" related forms to "addr" version. Change DW_FORM_loclistx
+    // to DW_FORM_sec_offset here.
+    std::optional<uint64_t> Index = Val.getAsSectionOffset();
+    if (!Index) {
+      CU.warn("cann't read the attribute. Dropping.", InputDieEntry);
+      return 0;
+    }
+    std::optional<uint64_t> Offset = CU.getOrigUnit().getLoclistOffset(*Index);
+    if (!Offset) {
+      CU.warn("cann't read the attribute. Dropping.", InputDieEntry);
+      return 0;
+    }
+
+    Value = *Offset;
+    ResultingForm = dwarf::DW_FORM_sec_offset;
+  } else if (AttrSpec.Attr == dwarf::DW_AT_high_pc &&
+             InputDieEntry->getTag() == dwarf::DW_TAG_compile_unit) {
+    std::optional<uint64_t> LowPC = CU.getLowPc();
+    if (!LowPC)
+      return 0;
+    // Dwarf >= 4 high_pc is an size, not an address.
+    Value = CU.getHighPc() - *LowPC;
+  } else if (AttrSpec.Attr == dwarf::DW_AT_addr_base) {
+    DebugInfoOutputSection.notePatchWithOffsetUpdate(
+        DebugOffsetPatch{AttrOutOffset,
+                         &CU.getSectionDescriptor(DebugSectionKind::DebugAddr),
+                         true},
+        PatchesOffsets);
+
+    // Use size of .debug_addr header(8) as attribute value. The offset to
+    // .debug_addr would be added later while patching.
+    Value = 8;
+  } else if (AttrSpec.Form == dwarf::DW_FORM_sec_offset)
+    Value = *Val.getAsSectionOffset();
+  else if (AttrSpec.Form == dwarf::DW_FORM_sdata)
+    Value = *Val.getAsSignedConstant();
+  else if (auto OptionalValue = Val.getAsUnsignedConstant())
+    Value = *OptionalValue;
+  else {
+    CU.warn("unsupported scalar attribute form. Dropping attribute.",
+            InputDieEntry);
+    return 0;
+  }
+
+  if (AttrSpec.Attr == dwarf::DW_AT_ranges ||
+      AttrSpec.Attr == dwarf::DW_AT_start_scope) {
+    // Create patch for the range offset value.
+    DebugInfoOutputSection.notePatchWithOffsetUpdate(
+        DebugRangePatch{{AttrOutOffset},
+                        InputDieEntry->getTag() == dwarf::DW_TAG_compile_unit},
+        PatchesOffsets);
+    AttrInfo.HasRanges = true;
+  } else if (DWARFAttribute::mayHaveLocationList(AttrSpec.Attr) &&
+             dwarf::doesFormBelongToClass(AttrSpec.Form,
+                                          DWARFFormValue::FC_SectionOffset,
+                                          CU.getOrigUnit().getVersion())) {
+    int64_t AddrAdjustmentValue = 0;
+    if (VarAddressAdjustment)
+      AddrAdjustmentValue = *VarAddressAdjustment;
+    else if (FuncAddressAdjustment)
+      AddrAdjustmentValue = *FuncAddressAdjustment;
+
+    // Create patch for the location offset value.
+    DebugInfoOutputSection.notePatchWithOffsetUpdate(
+        DebugLocPatch{{AttrOutOffset}, AddrAdjustmentValue}, PatchesOffsets);
+  } else if (AttrSpec.Attr == dwarf::DW_AT_declaration && Value)
+    AttrInfo.IsDeclaration = true;
+
+  return Generator.addScalarAttribute(AttrSpec.Attr, ResultingForm, Value)
+      .second;
+}
+
+size_t DIEAttributeCloner::cloneBlockAttr(
+    const DWARFFormValue &Val,
+    const DWARFAbbreviationDeclaration::AttributeSpec &AttrSpec) {
+
+  size_t NumberOfPatchesAtStart = PatchesOffsets.size();
+
+  // If the block is a DWARF Expression, clone it into the temporary
+  // buffer using cloneExpression(), otherwise copy the data directly.
+  SmallVector<uint8_t, 32> Buffer;
+  ArrayRef<uint8_t> Bytes = *Val.getAsBlock();
+  if (DWARFAttribute::mayHaveLocationExpr(AttrSpec.Attr) &&
+      (Val.isFormClass(DWARFFormValue::FC_Block) ||
+       Val.isFormClass(DWARFFormValue::FC_Exprloc))) {
+    DWARFUnit &OrigUnit = CU.getOrigUnit();
+    DataExtractor Data(StringRef((const char *)Bytes.data(), Bytes.size()),
+                       OrigUnit.isLittleEndian(),
+                       OrigUnit.getAddressByteSize());
+    DWARFExpression Expr(Data, OrigUnit.getAddressByteSize(),
+                         OrigUnit.getFormParams().Format);
+
+    CU.cloneDieAttrExpression(Expr, Buffer, DebugInfoOutputSection,
+                              VarAddressAdjustment, PatchesOffsets);
+    Bytes = Buffer;
+  }
+
+  // The expression location data might be updated and exceed the original size.
+  // Check whether the new data fits into the original form.
+  dwarf::Form ResultForm = AttrSpec.Form;
+  if ((ResultForm == dwarf::DW_FORM_block1 && Bytes.size() > UINT8_MAX) ||
+      (ResultForm == dwarf::DW_FORM_block2 && Bytes.size() > UINT16_MAX) ||
+      (ResultForm == dwarf::DW_FORM_block4 && Bytes.size() > UINT32_MAX))
+    ResultForm = dwarf::DW_FORM_block;
+
+  size_t FinalAttributeSize;
+  if (AttrSpec.Form == dwarf::DW_FORM_exprloc)
+    FinalAttributeSize =
+        Generator.addLocationAttribute(AttrSpec.Attr, ResultForm, Bytes).second;
+  else
+    FinalAttributeSize =
+        Generator.addBlockAttribute(AttrSpec.Attr, ResultForm, Bytes).second;
+
+  // Update patches offsets with the size of length field for Bytes.
+  for (size_t Idx = NumberOfPatchesAtStart; Idx < PatchesOffsets.size();
+       Idx++) {
+    assert(FinalAttributeSize > Bytes.size());
+    *PatchesOffsets[Idx] +=
+        (AttrOutOffset + (FinalAttributeSize - Bytes.size()));
+  }
+
+  return FinalAttributeSize;
+}
+
+size_t DIEAttributeCloner::cloneAddressAttr(
+    const DWARFFormValue &Val,
+    const DWARFAbbreviationDeclaration::AttributeSpec &AttrSpec) {
+  if (AttrSpec.Attr == dwarf::DW_AT_low_pc)
+    AttrInfo.HasLowPc = true;
+
+  if (CU.getGlobalData().getOptions().UpdateIndexTablesOnly)
+    return Generator
+        .addScalarAttribute(AttrSpec.Attr, AttrSpec.Form, Val.getRawUValue())
+        .second;
+
+  // Cloned Die may have address attributes relocated to a
+  // totally unrelated value. This can happen:
+  //   - If high_pc is an address (Dwarf version == 2), then it might have been
+  //     relocated to a totally unrelated value (because the end address in the
+  //     object file might be start address of another function which got moved
+  //     independently by the linker).
+  //   - If address relocated in an inline_subprogram that happens at the
+  //     beginning of its inlining function.
+  //  To avoid above cases and to not apply relocation twice (in
+  //  applyValidRelocs and here), read address attribute from InputDIE and apply
+  //  Info.PCOffset here.
+
+  std::optional<DWARFFormValue> AddrAttribute =
+      CU.find(InputDieEntry, AttrSpec.Attr);
+  if (!AddrAttribute)
+    llvm_unreachable("Cann't find attribute");
+
+  std::optional<uint64_t> Addr = AddrAttribute->getAsAddress();
+  if (!Addr) {
+    CU.warn("cann't read address attribute value.");
+    return 0;
+  }
+
+  if (InputDieEntry->getTag() == dwarf::DW_TAG_compile_unit &&
+      AttrSpec.Attr == dwarf::DW_AT_low_pc) {
+    if (std::optional<uint64_t> LowPC = CU.getLowPc())
+      Addr = *LowPC;
+    else
+      return 0;
+  } else if (InputDieEntry->getTag() == dwarf::DW_TAG_compile_unit &&
+             AttrSpec.Attr == dwarf::DW_AT_high_pc) {
+    if (uint64_t HighPc = CU.getHighPc())
+      Addr = HighPc;
+    else
+      return 0;
+  } else {
+    if (VarAddressAdjustment)
+      *Addr += *VarAddressAdjustment;
+    else if (FuncAddressAdjustment)
+      *Addr += *FuncAddressAdjustment;
+  }
+
+  if (AttrSpec.Form == dwarf::DW_FORM_addr) {
+    return Generator.addScalarAttribute(AttrSpec.Attr, AttrSpec.Form, *Addr)
+        .second;
+  }
+
+  return Generator
+      .addScalarAttribute(AttrSpec.Attr, dwarf::Form::DW_FORM_addrx,
+                          CU.getAddrIndex(*Addr))
+      .second;
+}
+
+unsigned DIEAttributeCloner::finalizeAbbreviations(bool HasChildrenToClone) {
+  size_t SizeOfAbbreviationNumber =
+      Generator.finalizeAbbreviations(HasChildrenToClone);
+
+  // We need to update patches offsets after we know the size of the
+  // abbreviation number.
+  updatePatchesWithSizeOfAbbreviationNumber(SizeOfAbbreviationNumber);
+
+  // Add the size of the abbreviation number to the output offset.
+  AttrOutOffset += SizeOfAbbreviationNumber;
+
+  return AttrOutOffset;
+}
+
+} // end of namespace dwarflinker_parallel
+} // namespace llvm

llvm/lib/DWARFLinkerParallel/DIEGenerator.h

+//===- DIEGenerator.h -------------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_DWARFLINKERPARALLEL_DIEGENERATOR_H
+#define LLVM_LIB_DWARFLINKERPARALLEL_DIEGENERATOR_H
+
+#include "DWARFLinkerGlobalData.h"
+#include "DWARFLinkerUnit.h"
+#include "llvm/CodeGen/DIE.h"
+#include "llvm/Support/LEB128.h"
+
+namespace llvm {
+namespace dwarflinker_parallel {
+
+/// This class is a helper to create output DIE tree.
+class DIEGenerator {
+public:
+  DIEGenerator(BumpPtrAllocator &Allocator, DwarfUnit &CU)
+      : Allocator(Allocator), CU(CU) {}
+
+  /// Creates a DIE of specified tag \p DieTag and \p OutOffset.
+  DIE *createDIE(dwarf::Tag DieTag, uint32_t OutOffset) {
+    OutputDIE = DIE::get(Allocator, DieTag);
+
+    OutputDIE->setOffset(OutOffset);
+
+    return OutputDIE;
+  }
+
+  /// Adds a specified \p Child to the current DIE.
+  void addChild(DIE *Child) {
+    assert(Child != nullptr);
+    assert(OutputDIE != nullptr);
+
+    OutputDIE->addChild(Child);
+  }
+
+  /// Adds specified scalar attribute to the current DIE.
+  std::pair<DIEValue &, size_t> addScalarAttribute(dwarf::Attribute Attr,
+                                                   dwarf::Form AttrForm,
+                                                   uint64_t Value) {
+    return addAttribute(Attr, AttrForm, DIEInteger(Value));
+  }
+
+  /// Adds specified location attribute to the current DIE.
+  std::pair<DIEValue &, size_t> addLocationAttribute(dwarf::Attribute Attr,
+                                                     dwarf::Form AttrForm,
+                                                     ArrayRef<uint8_t> Bytes) {
+    DIELoc *Loc = new (Allocator) DIELoc;
+    for (auto Byte : Bytes)
+      static_cast<DIEValueList *>(Loc)->addValue(
+          Allocator, static_cast<dwarf::Attribute>(0), dwarf::DW_FORM_data1,
+          DIEInteger(Byte));
+    Loc->setSize(Bytes.size());
+
+    return addAttribute(Attr, AttrForm, Loc);
+  }
+
+  /// Adds specified block or exprloc attribute to the current DIE.
+  std::pair<DIEValue &, size_t> addBlockAttribute(dwarf::Attribute Attr,
+                                                  dwarf::Form AttrForm,
+                                                  ArrayRef<uint8_t> Bytes) {
+    // The expression location data might be updated and exceed the original
+    // size. Check whether the new data fits into the original form.
+    assert((AttrForm == dwarf::DW_FORM_block) ||
+           (AttrForm == dwarf::DW_FORM_exprloc) ||
+           (AttrForm == dwarf::DW_FORM_block1 && Bytes.size() <= UINT8_MAX) ||
+           (AttrForm == dwarf::DW_FORM_block2 && Bytes.size() <= UINT16_MAX) ||
+           (AttrForm == dwarf::DW_FORM_block4 && Bytes.size() <= UINT32_MAX));
+
+    DIEBlock *Block = new (Allocator) DIEBlock;
+    for (auto Byte : Bytes)
+      static_cast<DIEValueList *>(Block)->addValue(
+          Allocator, static_cast<dwarf::Attribute>(0), dwarf::DW_FORM_data1,
+          DIEInteger(Byte));
+    Block->setSize(Bytes.size());
+
+    return addAttribute(Attr, AttrForm, Block);
+  }
+
+  /// Adds specified location list attribute to the current DIE.
+  std::pair<DIEValue &, size_t> addLocListAttribute(dwarf::Attribute Attr,
+                                                    dwarf::Form AttrForm,
+                                                    uint64_t Value) {
+    return addAttribute(Attr, AttrForm, DIELocList(Value));
+  }
+
+  /// Adds string attribute with dummy offset to the current DIE.
+  std::pair<DIEValue &, size_t>
+  addStringPlaceholderAttribute(dwarf::Attribute Attr, dwarf::Form AttrForm) {
+    assert(AttrForm == dwarf::DW_FORM_strp ||
+           AttrForm == dwarf::DW_FORM_line_strp);
+    return addAttribute(Attr, AttrForm, DIEInteger(0xBADDEF));
+  }
+
+  /// Adds inplace string attribute to the current DIE.
+  std::pair<DIEValue &, size_t> addInplaceString(dwarf::Attribute Attr,
+                                                 StringRef String) {
+    DIEBlock *Block = new (Allocator) DIEBlock;
+    for (auto Byte : String.bytes())
+      static_cast<DIEValueList *>(Block)->addValue(
+          Allocator, static_cast<dwarf::Attribute>(0), dwarf::DW_FORM_data1,
+          DIEInteger(Byte));
+
+    static_cast<DIEValueList *>(Block)->addValue(
+        Allocator, static_cast<dwarf::Attribute>(0), dwarf::DW_FORM_data1,
+        DIEInteger(0));
+    Block->setSize(String.size() + 1);
+
+    DIEValue &ValueRef =
+        *OutputDIE->addValue(Allocator, Attr, dwarf::DW_FORM_string, Block);
+    return std::pair<DIEValue &, size_t>(ValueRef, String.size() + 1);
+  }
+
+  /// Creates appreviations for the current DIE. Returns value of
+  /// abbreviation number.
+  size_t finalizeAbbreviations(bool CHILDREN_yes) {
+    // Create abbreviations for output DIE.
+    DIEAbbrev NewAbbrev = OutputDIE->generateAbbrev();
+    if (CHILDREN_yes)
+      NewAbbrev.setChildrenFlag(dwarf::DW_CHILDREN_yes);
+
+    CU.assignAbbrev(NewAbbrev);
+    OutputDIE->setAbbrevNumber(NewAbbrev.getNumber());
+
+    return getULEB128Size(OutputDIE->getAbbrevNumber());
+  }
+
+protected:
+  template <typename T>
+  std::pair<DIEValue &, size_t> addAttribute(dwarf::Attribute Attr,
+                                             dwarf::Form AttrForm, T &&Value) {
+    DIEValue &ValueRef =
+        *OutputDIE->addValue(Allocator, Attr, AttrForm, std::forward<T>(Value));
+    unsigned ValueSize = ValueRef.sizeOf(CU.getFormParams());
+    return std::pair<DIEValue &, size_t>(ValueRef, ValueSize);
+  }
+
+  // Allocator for output DIEs and values.
+  BumpPtrAllocator &Allocator;
+
+  // Unit for the output DIE.
+  DwarfUnit &CU;
+
+  // OutputDIE.
+  DIE *OutputDIE = nullptr;
+};
+
+} // end of namespace dwarflinker_parallel
+} // end namespace llvm
+
+#endif // LLVM_LIB_DWARFLINKERPARALLEL_DIEGENERATOR_H

llvm/lib/DWARFLinkerParallel/DWARFEmitterImpl.h

 //===- DwarfEmitterImpl.h ---------------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIB_DWARFLINKERPARALLEL_DWARFEMITTERIMPL_H
 #define LLVM_LIB_DWARFLINKERPARALLEL_DWARFEMITTERIMPL_H
 
 #include "DWARFLinkerCompileUnit.h"
 #include "llvm/BinaryFormat/Swift.h"
 #include "llvm/CodeGen/AccelTable.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/DWARFLinkerParallel/DWARFLinker.h"
-#include "llvm/DWARFLinkerParallel/StringTable.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCInstrInfo.h"
 #include "llvm/MC/MCObjectFileInfo.h"
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCStreamer.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/Target/TargetMachine.h"

 ///   InitializeAllAsmPrinters();
 
 template <typename DataT> class AccelTable;
 class MCCodeEmitter;
 class DWARFDebugMacro;
 
 namespace dwarflinker_parallel {
 
-struct UnitStartSymbol {
-  unsigned UnitID = 0;
-  MCSymbol *Symbol = 0;
-};
-using UnitStartSymbolsTy = SmallVector<UnitStartSymbol>;
-using Offset2UnitMapTy = DenseMap<uint64_t, CompileUnit *>;
-
-struct RangeAttrPatch;
-struct LocAttrPatch;
-
-/// The Dwarf emission logic.
-///
-/// All interactions with the MC layer that is used to build the debug
-/// information binary representation are handled in this class.
+/// This class emits DWARF data to the output stream. It emits already
+/// generated section data and specific data, which could not be generated
+/// by CompileUnit.
 class DwarfEmitterImpl : public ExtraDwarfEmitter {
 public:
   DwarfEmitterImpl(DWARFLinker::OutputFileType OutFileType,
-                   raw_pwrite_stream &OutFile,
-                   std::function<StringRef(StringRef Input)> Translator,
-                   DWARFLinker::MessageHandlerTy Warning)
-      : OutFile(OutFile), OutFileType(OutFileType), Translator(Translator),
-        WarningHandler(Warning) {}
+                   raw_pwrite_stream &OutFile)
+      : OutFile(OutFile), OutFileType(OutFileType) {}
 
+  /// Initialize AsmPrinter data.
   Error init(Triple TheTriple, StringRef Swift5ReflectionSegmentName);
 
+  /// Returns triple of output stream.
+  const Triple &getTargetTriple() { return MC->getTargetTriple(); }
+
   /// Dump the file to the disk.
   void finish() override { MS->finish(); }
 
+  /// Returns AsmPrinter.
   AsmPrinter &getAsmPrinter() const override { return *Asm; }
 
-  /// Set the current output section to debug_info and change
-  /// the MC Dwarf version to \p DwarfVersion.
-  void switchToDebugInfoSection(unsigned DwarfVersion) {}
-
   /// Emit the swift_ast section stored in \p Buffer.
-  void emitSwiftAST(StringRef Buffer) override {}
+  void emitSwiftAST(StringRef Buffer) override;
 
   /// Emit the swift reflection section stored in \p Buffer.
   void emitSwiftReflectionSection(
       llvm::binaryformat::Swift5ReflectionSectionKind ReflSectionKind,
-      StringRef Buffer, uint32_t Alignment, uint32_t Size) override {}
-
-  void emitPaperTrailWarningsDie(DIE &Die) {}
+      StringRef Buffer, uint32_t Alignment, uint32_t) override;
 
-  void emitSectionContents(StringRef SecData, StringRef SecName) override {}
+  /// Emit specified section data.
+  void emitSectionContents(StringRef SecData, StringRef SecName) override;
 
-  MCSymbol *emitTempSym(StringRef SecName, StringRef SymName) override {
-    return nullptr;
-  }
+  /// Emit temporary symbol.
+  MCSymbol *emitTempSym(StringRef SecName, StringRef SymName) override;
 
+  /// Emit abbreviations.
   void emitAbbrevs(const SmallVector<std::unique_ptr<DIEAbbrev>> &Abbrevs,
-                   unsigned DwarfVersion) {}
-
-  void emitStrings(const StringTable &Strings) {}
-
-  void emitLineStrings(const StringTable &Strings) {}
-
-  void emitDebugNames(AccelTable<DWARF5AccelTableStaticData> &,
-                      UnitStartSymbolsTy &UnitOffsets) {}
-
-  void emitAppleNamespaces(AccelTable<AppleAccelTableStaticOffsetData> &) {}
-
-  void emitAppleNames(AccelTable<AppleAccelTableStaticOffsetData> &) {}
-
-  void emitAppleObjc(AccelTable<AppleAccelTableStaticOffsetData> &) {}
-
-  void emitAppleTypes(AccelTable<AppleAccelTableStaticTypeData> &) {}
-
-  MCSymbol *emitDwarfDebugRangeListHeader(const CompileUnit &Unit) {
-    return nullptr;
-  }
-
-  void emitDwarfDebugRangeListFragment(const CompileUnit &Unit,
-                                       const AddressRanges &LinkedRanges,
-                                       RangeAttrPatch &Patch) {}
-
-  void emitDwarfDebugRangeListFooter(const CompileUnit &Unit,
-                                     MCSymbol *EndLabel) {}
-
-  MCSymbol *emitDwarfDebugLocListHeader(const CompileUnit &Unit) {
-    return nullptr;
-  }
-
-  void emitDwarfDebugLocListFragment(
-      const CompileUnit &Unit,
-      const DWARFLocationExpressionsVector &LinkedLocationExpression,
-      LocAttrPatch &Patch) {}
-
-  void emitDwarfDebugLocListFooter(const CompileUnit &Unit,
-                                   MCSymbol *EndLabel) {}
+                   unsigned DwarfVersion);
 
-  void emitDwarfDebugArangesTable(const CompileUnit &Unit,
-                                  const AddressRanges &LinkedRanges) {}
+  /// Emit zero string into the .debug_str table.
+  void emitZeroString();
 
-  void translateLineTable(DataExtractor LineData, uint64_t Offset) {}
+  /// Emit strings into the .debug_str section.
+  void emitStrings(ArrayList<DebugStrPatch> &StringPatches,
+                   const StringEntryToDwarfStringPoolEntryMap &Strings,
+                   uint64_t &NextOffset);
+
+  /// Emit strings into the .debug_line_str section.
+  void emitLineStrings(ArrayList<DebugLineStrPatch> &StringPatches,
+                       const StringEntryToDwarfStringPoolEntryMap &Strings,
+                       uint64_t &NextOffset);
 
-  void emitLineTableForUnit(MCDwarfLineTableParams Params,
-                            StringRef PrologueBytes, unsigned MinInstLength,
-                            std::vector<DWARFDebugLine::Row> &Rows,
-                            unsigned AdddressSize) {}
+  /// Emit compile unit header.
+  void emitCompileUnitHeader(DwarfUnit &Unit);
 
-  void emitLineTableForUnit(const DWARFDebugLine::LineTable &LineTable,
-                            const CompileUnit &Unit, const StringTable &Strings,
-                            const StringTable &LineTableStrings) {}
-
-  void emitPubNamesForUnit(const CompileUnit &Unit) {}
-
-  void emitPubTypesForUnit(const CompileUnit &Unit) {}
-
-  void emitCIE(StringRef CIEBytes) {}
-
-  void emitFDE(uint32_t CIEOffset, uint32_t AddreSize, uint64_t Address,
-               StringRef Bytes) {}
-
-  void emitCompileUnitHeader(CompileUnit &Unit, unsigned DwarfVersion) {}
-
-  void emitDIE(DIE &Die) {}
-
-  void emitMacroTables(DWARFContext *Context,
-                       const Offset2UnitMapTy &UnitMacroMap,
-                       StringTable &Strings) {}
-
-  /// Returns size of generated .debug_line section.
-  uint64_t getDebugLineSectionSize() const { return LineSectionSize; }
-
-  /// Returns size of generated .debug_frame section.
-  uint64_t getDebugFrameSectionSize() const { return FrameSectionSize; }
-
-  /// Returns size of generated .debug_ranges section.
-  uint64_t getDebugRangesSectionSize() const { return RangesSectionSize; }
-
-  /// Returns size of generated .debug_rnglists section.
-  uint64_t getDebugRngListsSectionSize() const { return RngListsSectionSize; }
+  /// Emit DIE recursively.
+  void emitDIE(DIE &Die);
 
   /// Returns size of generated .debug_info section.
   uint64_t getDebugInfoSectionSize() const { return DebugInfoSectionSize; }
 
-  /// Returns size of generated .debug_macinfo section.
-  uint64_t getDebugMacInfoSectionSize() const { return MacInfoSectionSize; }
-
-  /// Returns size of generated .debug_macro section.
-  uint64_t getDebugMacroSectionSize() const { return MacroSectionSize; }
-
-  /// Returns size of generated .debug_loc section.
-  uint64_t getDebugLocSectionSize() const { return LocSectionSize; }
-
-  /// Returns size of generated .debug_loclists section.
-  uint64_t getDebugLocListsSectionSize() const { return LocListsSectionSize; }
-
 private:
-  inline void warn(const Twine &Warning, StringRef Context = "") {
-    if (WarningHandler)
-      WarningHandler(Warning, Context, nullptr);
-  }
-
-  void emitMacroTableImpl(const DWARFDebugMacro *MacroTable,
-                          const Offset2UnitMapTy &UnitMacroMap,
-                          StringPool &StringPool, uint64_t &OutOffset) {}
-
-  /// Emit piece of .debug_ranges for \p LinkedRanges.
-  void emitDwarfDebugRangesTableFragment(const CompileUnit &Unit,
-                                         const AddressRanges &LinkedRanges,
-                                         RangeAttrPatch &Patch) {}
-
-  /// Emit piece of .debug_rnglists for \p LinkedRanges.
-  void emitDwarfDebugRngListsTableFragment(const CompileUnit &Unit,
-                                           const AddressRanges &LinkedRanges,
-                                           RangeAttrPatch &Patch) {}
-
-  /// Emit piece of .debug_loc for \p LinkedRanges.
-  void emitDwarfDebugLocTableFragment(
-      const CompileUnit &Unit,
-      const DWARFLocationExpressionsVector &LinkedLocationExpression,
-      LocAttrPatch &Patch) {}
-
-  /// Emit piece of .debug_loclists for \p LinkedRanges.
-  void emitDwarfDebugLocListsTableFragment(
-      const CompileUnit &Unit,
-      const DWARFLocationExpressionsVector &LinkedLocationExpression,
-      LocAttrPatch &Patch) {}
+  // Enumerate all string patches and write them into the destination section.
+  // Order of patches is the same as in original input file. To avoid emitting
+  // the same string twice we accumulate NextOffset value. Thus if string
+  // offset smaller than NextOffset value then the patch is skipped (as that
+  // string was emitted earlier).
+  template <typename PatchTy>
+  void emitStringsImpl(ArrayList<PatchTy> &StringPatches,
+                       const StringEntryToDwarfStringPoolEntryMap &Strings,
+                       uint64_t &NextOffset, MCSection *OutSection);
+
+  MCSection *switchSection(StringRef SecName);
 
   /// \defgroup MCObjects MC layer objects constructed by the streamer
   /// @{
   std::unique_ptr<MCRegisterInfo> MRI;
   std::unique_ptr<MCAsmInfo> MAI;
   std::unique_ptr<MCObjectFileInfo> MOFI;
   std::unique_ptr<MCContext> MC;
   MCAsmBackend *MAB; // Owned by MCStreamer
   std::unique_ptr<MCInstrInfo> MII;
   std::unique_ptr<MCSubtargetInfo> MSTI;
   MCInstPrinter *MIP; // Owned by AsmPrinter
   MCCodeEmitter *MCE; // Owned by MCStreamer
   MCStreamer *MS;     // Owned by AsmPrinter
   std::unique_ptr<TargetMachine> TM;
   std::unique_ptr<AsmPrinter> Asm;
   /// @}
 
   /// The output file we stream the linked Dwarf to.
   raw_pwrite_stream &OutFile;
   DWARFLinker::OutputFileType OutFileType = DWARFLinker::OutputFileType::Object;
-  std::function<StringRef(StringRef Input)> Translator;
 
-  uint64_t RangesSectionSize = 0;
-  uint64_t RngListsSectionSize = 0;
-  uint64_t LocSectionSize = 0;
-  uint64_t LocListsSectionSize = 0;
-  uint64_t LineSectionSize = 0;
-  uint64_t FrameSectionSize = 0;
   uint64_t DebugInfoSectionSize = 0;
-  uint64_t MacInfoSectionSize = 0;
-  uint64_t MacroSectionSize = 0;
-
-  /// Keep track of emitted CUs and their Unique ID.
-  struct EmittedUnit {
-    unsigned ID;
-    MCSymbol *LabelBegin;
-  };
-  std::vector<EmittedUnit> EmittedUnitsTy;
-
-  /// Emit the pubnames or pubtypes section contribution for \p
-  /// Unit into \p Sec. The data is provided in \p Names.
-  void emitPubSectionForUnit(MCSection *Sec, StringRef Name,
-                             const CompileUnit &Unit,
-                             const std::vector<CompileUnit::AccelInfo> &Names);
-
-  DWARFLinker::MessageHandlerTy WarningHandler = nullptr;
 };
 
 } // end namespace dwarflinker_parallel
 } // end namespace llvm
 
 #endif // LLVM_LIB_DWARFLINKERPARALLEL_DWARFEMITTERIMPL_H

llvm/lib/DWARFLinkerParallel/DWARFEmitterImpl.cpp

Error DwarfEmitterImpl::init(Triple TheTriple,
 
   Asm.reset(TheTarget->createAsmPrinter(*TM, std::unique_ptr<MCStreamer>(MS)));
   if (!Asm)
     return createStringError(std::errc::invalid_argument,
                              "no asm printer for target %s",
                              TripleName.c_str());
   Asm->setDwarfUsesRelocationsAcrossSections(false);
 
-  RangesSectionSize = 0;
-  RngListsSectionSize = 0;
-  LocSectionSize = 0;
-  LocListsSectionSize = 0;
-  LineSectionSize = 0;
-  FrameSectionSize = 0;
   DebugInfoSectionSize = 0;
-  MacInfoSectionSize = 0;
-  MacroSectionSize = 0;
 
   return Error::success();
 }
 
+void DwarfEmitterImpl::emitSwiftAST(StringRef Buffer) {
+  MCSection *SwiftASTSection = MOFI->getDwarfSwiftASTSection();
+  SwiftASTSection->setAlignment(Align(32));
+  MS->switchSection(SwiftASTSection);
+  MS->emitBytes(Buffer);
+}
+
+/// Emit the swift reflection section stored in \p Buffer.
+void DwarfEmitterImpl::emitSwiftReflectionSection(
+    llvm::binaryformat::Swift5ReflectionSectionKind ReflSectionKind,
+    StringRef Buffer, uint32_t Alignment, uint32_t) {
+  MCSection *ReflectionSection =
+      MOFI->getSwift5ReflectionSection(ReflSectionKind);
+  if (ReflectionSection == nullptr)
+    return;
+  ReflectionSection->setAlignment(Align(Alignment));
+  MS->switchSection(ReflectionSection);
+  MS->emitBytes(Buffer);
+}
+
+void DwarfEmitterImpl::emitSectionContents(StringRef SecData,
+                                           StringRef SecName) {
+  if (MCSection *Section = switchSection(SecName)) {
+    MS->switchSection(Section);
+
+    MS->emitBytes(SecData);
+  }
+}
+
+MCSection *DwarfEmitterImpl::switchSection(StringRef SecName) {
+  return StringSwitch<MCSection *>(SecName)
+      .Case("debug_info", MC->getObjectFileInfo()->getDwarfInfoSection())
+      .Case("debug_abbrev", MC->getObjectFileInfo()->getDwarfAbbrevSection())
+      .Case("debug_line", MC->getObjectFileInfo()->getDwarfLineSection())
+      .Case("debug_loc", MC->getObjectFileInfo()->getDwarfLocSection())
+      .Case("debug_ranges", MC->getObjectFileInfo()->getDwarfRangesSection())
+      .Case("debug_frame", MC->getObjectFileInfo()->getDwarfFrameSection())
+      .Case("debug_aranges", MC->getObjectFileInfo()->getDwarfARangesSection())
+      .Case("debug_rnglists",
+            MC->getObjectFileInfo()->getDwarfRnglistsSection())
+      .Case("debug_loclists",
+            MC->getObjectFileInfo()->getDwarfLoclistsSection())
+      .Case("debug_macro", MC->getObjectFileInfo()->getDwarfMacroSection())
+      .Case("debug_macinfo", MC->getObjectFileInfo()->getDwarfMacinfoSection())
+      .Case("debug_addr", MC->getObjectFileInfo()->getDwarfAddrSection())
+      .Default(nullptr);
+}
+
+MCSymbol *DwarfEmitterImpl::emitTempSym(StringRef SecName, StringRef SymName) {
+  if (MCSection *Section = switchSection(SecName)) {
+    MS->switchSection(Section);
+    MCSymbol *Res = Asm->createTempSymbol(SymName);
+    Asm->OutStreamer->emitLabel(Res);
+    return Res;
+  }
+
+  return nullptr;
+}
+
+void DwarfEmitterImpl::emitAbbrevs(
+    const SmallVector<std::unique_ptr<DIEAbbrev>> &Abbrevs,
+    unsigned DwarfVersion) {
+  MS->switchSection(MOFI->getDwarfAbbrevSection());
+  MC->setDwarfVersion(DwarfVersion);
+  Asm->emitDwarfAbbrevs(Abbrevs);
+}
+
+void DwarfEmitterImpl::emitZeroString() {
+  Asm->OutStreamer->switchSection(MOFI->getDwarfStrSection());
+
+  // Emit a null terminator for zero String.
+  Asm->emitInt8(0);
+}
+
+template <typename PatchTy>
+void DwarfEmitterImpl::emitStringsImpl(
+    ArrayList<PatchTy> &StringPatches,
+    const StringEntryToDwarfStringPoolEntryMap &Strings, uint64_t &NextOffset,
+    MCSection *OutSection) {
+  Asm->OutStreamer->switchSection(OutSection);
+
+  // Enumerate all string patches and write them into the destination section.
+  StringPatches.forEach([&](const PatchTy &Patch) {
+    DwarfStringPoolEntryWithExtString *StringToEmit =
+        Strings.getExistingEntry(Patch.String);
+    assert(StringToEmit->isIndexed());
+
+    // Patches can refer the same strings. We use accumulated NextOffset
+    // to understand whether corresponding string is already emitted.
+    // Skip patch if string is already emitted.
+    if (StringToEmit->Offset >= NextOffset) {
+      NextOffset = StringToEmit->Offset + StringToEmit->String.size() + 1;
+      // Emit the string itself.
+      Asm->OutStreamer->emitBytes(StringToEmit->String);
+      // Emit a null terminator.
+      Asm->emitInt8(0);
+    }
+  });
+}
+
+void DwarfEmitterImpl::emitStrings(
+    ArrayList<DebugStrPatch> &StringPatches,
+    const StringEntryToDwarfStringPoolEntryMap &Strings, uint64_t &NextOffset) {
+  emitStringsImpl<DebugStrPatch>(StringPatches, Strings, NextOffset,
+                                 MOFI->getDwarfStrSection());
+}
+
+void DwarfEmitterImpl::emitLineStrings(
+    ArrayList<DebugLineStrPatch> &StringPatches,
+    const StringEntryToDwarfStringPoolEntryMap &Strings, uint64_t &NextOffset) {
+  emitStringsImpl<DebugLineStrPatch>(StringPatches, Strings, NextOffset,
+                                     MOFI->getDwarfLineStrSection());
+}
+
+void DwarfEmitterImpl::emitCompileUnitHeader(DwarfUnit &Unit) {
+  MS->switchSection(MOFI->getDwarfInfoSection());
+  MC->setDwarfVersion(Unit.getVersion());
+
+  // Emit size of content not including length itself. The size has already
+  // been computed in CompileUnit::computeOffsets(). Subtract 4 to that size to
+  // account for the length field.
+  Asm->emitInt32(Unit.getHeaderSize() + Unit.getOutUnitDIE()->getSize() - 4);
+  Asm->emitInt16(Unit.getVersion());
+
+  if (Unit.getVersion() >= 5) {
+    Asm->emitInt8(dwarf::DW_UT_compile);
+    Asm->emitInt8(Unit.getFormParams().AddrSize);
+    // Proper offset to the abbreviations table will be set later.
+    Asm->emitInt32(0);
+    DebugInfoSectionSize += 12;
+  } else {
+    // Proper offset to the abbreviations table will be set later.
+    Asm->emitInt32(0);
+    Asm->emitInt8(Unit.getFormParams().AddrSize);
+    DebugInfoSectionSize += 11;
+  }
+}
+
+void DwarfEmitterImpl::emitDIE(DIE &Die) {
+  MS->switchSection(MOFI->getDwarfInfoSection());
+  Asm->emitDwarfDIE(Die);
+  DebugInfoSectionSize += Die.getSize();
+}
+
 } // end of namespace dwarflinker_parallel
 } // namespace llvm

llvm/lib/DWARFLinkerParallel/DWARFFile.cpp

+//=== DWARFFile.cpp -------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/DWARFLinkerParallel/DWARFFile.h"
+#include "DWARFLinkerGlobalData.h"
+
+llvm::dwarflinker_parallel::DWARFFile::DWARFFile(
+    StringRef Name, std::unique_ptr<DWARFContext> Dwarf,
+    std::unique_ptr<AddressesMap> Addresses,
+    const std::vector<std::string> &Warnings,
+    DWARFFile::UnloadCallbackTy UnloadFunc)
+    : FileName(Name), Dwarf(std::move(Dwarf)), Addresses(std::move(Addresses)),
+      Warnings(Warnings), UnloadFunc(UnloadFunc) {}

llvm/lib/DWARFLinkerParallel/DWARFLinkerCompileUnit.h

 //===- DWARFLinkerCompileUnit.h ---------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIB_DWARFLINKERPARALLEL_DWARFLINKERCOMPILEUNIT_H
 #define LLVM_LIB_DWARFLINKERPARALLEL_DWARFLINKERCOMPILEUNIT_H
 
 #include "DWARFLinkerUnit.h"
 #include "llvm/DWARFLinkerParallel/DWARFFile.h"
-#include "llvm/DWARFLinkerParallel/DWARFLinker.h"
 #include <optional>
 
 namespace llvm {
 namespace dwarflinker_parallel {
 
-struct LinkContext;
-class DWARFFile;
+using OffsetToUnitTy = function_ref<CompileUnit *(uint64_t Offset)>;
 
 /// Stores all information related to a compile unit, be it in its original
 /// instance of the object file or its brand new cloned and generated DIE tree.
 class CompileUnit : public DwarfUnit {
 public:
-  CompileUnit(LinkContext &, unsigned ID, StringRef ClangModuleName,
-              DWARFFile &File,
-              DWARFLinker::SwiftInterfacesMapTy *,
-              UnitMessageHandlerTy WarningHandler)
-      : DwarfUnit(ID, ClangModuleName, WarningHandler), ContaingFile(File) {
-    FormParams.Version = 4;
-    FormParams.Format = dwarf::DWARF32;
-    FormParams.AddrSize = 4;
-    UnitName = ContaingFile.FileName;
+  /// The stages of new compile unit processing.
+  enum class Stage : uint8_t {
+    /// Created, linked with input DWARF file.
+    CreatedNotLoaded = 0,
+
+    /// Input DWARF is loaded.
+    Loaded,
+
+    /// Input DWARF is analysed(DIEs pointing to the real code section are
+    /// discovered, type names are assigned if ODR is requested).
+    LivenessAnalysisDone,
+
+    /// Output DWARF is generated.
+    Cloned,
+
+    /// Offsets inside patch records are updated.
+    PatchesUpdated,
+
+    /// Resources(Input DWARF, Output DWARF tree) are released.
+    Cleaned,
+  };
+
+  CompileUnit(LinkingGlobalData &GlobalData, unsigned ID,
+              StringRef ClangModuleName, DWARFFile &File,
+              OffsetToUnitTy UnitFromOffset)
+      : DwarfUnit(GlobalData, ID, ClangModuleName), File(File),
+        getUnitFromOffset(UnitFromOffset), Stage(Stage::CreatedNotLoaded) {
+    UnitName = File.FileName;
   }
 
-  CompileUnit(LinkContext &, DWARFUnit &OrigUnit, unsigned ID,
+  CompileUnit(LinkingGlobalData &GlobalData, DWARFUnit &OrigUnit, unsigned ID,
               StringRef ClangModuleName, DWARFFile &File,
-              UnitMessageHandlerTy WarningHandler)
-      : DwarfUnit(ID, ClangModuleName, WarningHandler),
-        ContaingFile(File), OrigUnit(&OrigUnit) {
+              OffsetToUnitTy UnitFromOffset)
+      : DwarfUnit(GlobalData, ID, ClangModuleName), File(File),
+        OrigUnit(&OrigUnit), getUnitFromOffset(UnitFromOffset),
+        Stage(Stage::CreatedNotLoaded) {
     DWARFDie CUDie = OrigUnit.getUnitDIE();
     if (!CUDie)
       return;
 
-    if (File.Dwarf)
-      Endianess = File.Dwarf->isLittleEndian() ? support::endianness::little
-                                               : support::endianness::big;
-
-    FormParams.Version = OrigUnit.getVersion();
-    FormParams.Format = dwarf::DWARF32;
-    FormParams.AddrSize = OrigUnit.getAddressByteSize();
+    setOutputFormat(OrigUnit);
 
     Language = dwarf::toUnsigned(CUDie.find(dwarf::DW_AT_language), 0);
-
-    UnitName = ContaingFile.FileName;
+    if (const char *CUName = CUDie.getName(DINameKind::ShortName))
+      UnitName = CUName;
+    else
+      UnitName = File.FileName;
     SysRoot = dwarf::toStringRef(CUDie.find(dwarf::DW_AT_LLVM_sysroot)).str();
   }
 
+  /// Returns stage of overall processing.
+  Stage getStage() const { return Stage; }
+
+  /// Set stage of overall processing.
+  void setStage(Stage Stage) { this->Stage = Stage; }
+
+  /// Loads unit line table.
+  void loadLineTable();
+
+  /// Returns name of the file for the \p FileIdx
+  /// from the unit`s line table.
+  StringEntry *getFileName(unsigned FileIdx, StringPool &GlobalStrings);
+
+  /// Returns DWARFFile containing this compile unit.
+  const DWARFFile &getContaingFile() const { return File; }
+
+  /// Load DIEs of input compilation unit. \returns true if input DIEs
+  /// successfully loaded.
+  bool loadInputDIEs();
+
+  /// Reset compile units data(results of liveness analysis, clonning)
+  /// if current stage greater than Stage::Loaded. We need to reset data
+  /// as we are going to repeat stages.
+  void maybeResetToLoadedStage();
+
+  /// Collect references to parseable Swift interfaces in imported
+  /// DW_TAG_module blocks.
+  void analyzeImportedModule(const DWARFDebugInfoEntry *DieEntry);
+
+  /// Navigate DWARF tree and set die properties.
+  void analyzeDWARFStructure() {
+    analyzeDWARFStructureRec(getUnitDIE().getDebugInfoEntry(), false, false);
+  }
+
+  /// Cleanup unneeded resources after compile unit is cloned.
+  void cleanupDataAfterClonning();
+
+  /// After cloning stage the output DIEs offsets are deallocated.
+  /// This method copies output offsets for referenced DIEs into DIEs patches.
+  void updateDieRefPatchesWithClonedOffsets();
+
+  /// Kinds of placement for the output die.
+  enum DieOutputPlacement : uint8_t {
+    NotSet = 0,
+
+    /// Corresponding DIE goes to the type table only.
+    /// NOTE: Not used yet.
+    TypeTable = 1,
+
+    /// Corresponding DIE goes to the plain dwarf only.
+    PlainDwarf = 2,
+
+    /// Corresponding DIE goes to type table and to plain dwarf.
+    /// NOTE: Not used yet.
+    Both = 3,
+
+    /// Corresponding DIE needs to examine parent to determine
+    /// the point of placement.
+    /// NOTE: Not used yet.
+    Parent = 4
+  };
+
+  /// Information gathered about source DIEs.
+  struct DIEInfo {
+    DIEInfo() = default;
+    DIEInfo(const DIEInfo &Other) { Flags = Other.Flags.load(); }
+    DIEInfo &operator=(const DIEInfo &Other) {
+      Flags = Other.Flags.load();
+      return *this;
+    }
+
+    /// Data member keeping various flags.
+    std::atomic<uint16_t> Flags = {0};
+
+    /// \returns Placement kind for the corresponding die.
+    DieOutputPlacement getPlacement() const {
+      return DieOutputPlacement(Flags & 0x7);
+    }
+
+    /// Sets Placement kind for the corresponding die.
+    void setPlacement(DieOutputPlacement Placement) {
+      auto InputData = Flags.load();
+      while (!Flags.compare_exchange_weak(InputData,
+                                          ((InputData & ~0x7) | Placement))) {
+      }
+    }
+
+    /// Unsets Placement kind for the corresponding die.
+    void unsetPlacement() {
+      auto InputData = Flags.load();
+      while (!Flags.compare_exchange_weak(InputData, (InputData & ~0x7))) {
+      }
+    }
+
+    /// Sets Placement kind for the corresponding die.
+    bool setPlacementIfUnset(DieOutputPlacement Placement) {
+      auto InputData = Flags.load();
+      if ((InputData & 0x7) == NotSet)
+        if (Flags.compare_exchange_weak(InputData, (InputData | Placement)))
+          return true;
+
+      return false;
+    }
+
+#define SINGLE_FLAG_METHODS_SET(Name, Value)                                   \
+  bool get##Name() const { return Flags & Value; }                             \
+  void set##Name() {                                                           \
+    auto InputData = Flags.load();                                             \
+    while (!Flags.compare_exchange_weak(InputData, InputData | Value)) {       \
+    }                                                                          \
+  }                                                                            \
+  void unset##Name() {                                                         \
+    auto InputData = Flags.load();                                             \
+    while (!Flags.compare_exchange_weak(InputData, InputData & ~Value)) {      \
+    }                                                                          \
+  }
+
+    /// DIE is a part of the linked output.
+    SINGLE_FLAG_METHODS_SET(Keep, 0x08)
+
+    /// DIE has children which are part of the linked output.
+    SINGLE_FLAG_METHODS_SET(KeepChildren, 0x10)
+
+    /// DIE is referenced by other DIE.
+    SINGLE_FLAG_METHODS_SET(ReferrencedBy, 0x20)
+
+    /// DIE is in module scope.
+    SINGLE_FLAG_METHODS_SET(IsInMouduleScope, 0x40)
+
+    /// DIE is in function scope.
+    SINGLE_FLAG_METHODS_SET(IsInFunctionScope, 0x80)
+
+    void unsetFlagsWhichSetDuringLiveAnalysis() {
+      auto InputData = Flags.load();
+      while (!Flags.compare_exchange_weak(
+          InputData, InputData & ~(0x7 | 0x8 | 0x10 | 0x20))) {
+      }
+    }
+
+    /// Erase all flags.
+    void eraseData() { Flags = 0; }
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+    LLVM_DUMP_METHOD void dump();
+#endif
+  };
+
+  /// \defgroup Group of functions returning DIE info.
+  ///
+  /// @{
+
+  /// \p Idx index of the DIE.
+  /// \returns DieInfo descriptor.
+  DIEInfo &getDIEInfo(unsigned Idx) { return DieInfoArray[Idx]; }
+
+  /// \p Idx index of the DIE.
+  /// \returns DieInfo descriptor.
+  const DIEInfo &getDIEInfo(unsigned Idx) const { return DieInfoArray[Idx]; }
+
+  /// \p Idx index of the DIE.
+  /// \returns DieInfo descriptor.
+  DIEInfo &getDIEInfo(const DWARFDebugInfoEntry *Entry) {
+    return DieInfoArray[getOrigUnit().getDIEIndex(Entry)];
+  }
+
+  /// \p Idx index of the DIE.
+  /// \returns DieInfo descriptor.
+  const DIEInfo &getDIEInfo(const DWARFDebugInfoEntry *Entry) const {
+    return DieInfoArray[getOrigUnit().getDIEIndex(Entry)];
+  }
+
+  /// \p Die
+  /// \returns PlainDieInfo descriptor.
+  DIEInfo &getDIEInfo(const DWARFDie &Die) {
+    return DieInfoArray[getOrigUnit().getDIEIndex(Die)];
+  }
+
+  /// \p Die
+  /// \returns PlainDieInfo descriptor.
+  const DIEInfo &getDIEInfo(const DWARFDie &Die) const {
+    return DieInfoArray[getOrigUnit().getDIEIndex(Die)];
+  }
+
+  /// \p Idx index of the DIE.
+  /// \returns DieInfo descriptor.
+  uint64_t getDieOutOffset(uint32_t Idx) {
+    return reinterpret_cast<std::atomic<uint64_t> *>(&OutDieOffsetArray[Idx])
+        ->load();
+  }
+
+  /// \p Idx index of the DIE.
+  /// \returns DieInfo descriptor.
+  void rememberDieOutOffset(uint32_t Idx, uint64_t Offset) {
+    reinterpret_cast<std::atomic<uint64_t> *>(&OutDieOffsetArray[Idx])
+        ->store(Offset);
+  }
+
+  /// @}
+
+  /// Returns value of DW_AT_low_pc attribute.
+  std::optional<uint64_t> getLowPc() const { return LowPc; }
+
+  /// Returns value of DW_AT_high_pc attribute.
+  uint64_t getHighPc() const { return HighPc; }
+
+  /// Returns true if there is a label corresponding to the specified \p Addr.
+  bool hasLabelAt(uint64_t Addr) const { return Labels.count(Addr); }
+
+  /// Add the low_pc of a label that is relocated by applying
+  /// offset \p PCOffset.
+  void addLabelLowPc(uint64_t LabelLowPc, int64_t PcOffset);
+
+  /// Resolve the DIE attribute reference that has been extracted in \p
+  /// RefValue. The resulting DIE might be in another CompileUnit.
+  /// \returns referenced die and corresponding compilation unit.
+  ///          compilation unit is null if reference could not be resolved.
+  std::optional<std::pair<CompileUnit *, uint32_t>>
+  resolveDIEReference(const DWARFFormValue &RefValue);
+  /// @}
+
+  /// Add a function range [\p LowPC, \p HighPC) that is relocated by applying
+  /// offset \p PCOffset.
+  void addFunctionRange(uint64_t LowPC, uint64_t HighPC, int64_t PCOffset);
+
+  /// Returns function ranges of this unit.
+  const RangesTy &getFunctionRanges() const { return Ranges; }
+
+  /// Clone and emit this compilation unit.
+  Error cloneAndEmit(std::optional<Triple> TargetTriple);
+
+  /// Clone and emit debug locations(.debug_loc/.debug_loclists).
+  Error cloneAndEmitDebugLocations();
+
+  /// Clone and emit ranges.
+  Error cloneAndEmitRanges();
+
+  /// Clone and emit debug macros(.debug_macinfo/.debug_macro).
+  Error cloneAndEmitDebugMacro();
+
+  // Clone input DIE entry.
+  DIE *cloneDIE(const DWARFDebugInfoEntry *InputDieEntry, uint64_t OutOffset,
+                std::optional<int64_t> FuncAddressAdjustment,
+                std::optional<int64_t> VarAddressAdjustment,
+                BumpPtrAllocator &Allocator);
+
+  // Clone and emit line table.
+  Error cloneAndEmitLineTable(Triple &TargetTriple);
+
+  /// Clone attribute location axpression.
+  void cloneDieAttrExpression(const DWARFExpression &InputExpression,
+                              SmallVectorImpl<uint8_t> &OutputExpression,
+                              SectionDescriptor &Section,
+                              std::optional<int64_t> VarAddressAdjustment,
+                              OffsetsPtrVector &PatchesOffsets);
+
+  /// Returns index(inside .debug_addr) of an address.
+  uint64_t getAddrIndex(uint64_t Addr) {
+    DenseMap<uint64_t, uint64_t>::iterator It = AddrIndexMap.find(Addr);
+    if (It == AddrIndexMap.end()) {
+      It = AddrIndexMap.insert(std::make_pair(Addr, Addrs.size())).first;
+      Addrs.push_back(Addr);
+    }
+    return It->second;
+  }
+
   /// \defgroup Helper methods to access OrigUnit.
   ///
   /// @{
 
   /// Returns paired compile unit from input DWARF.
   DWARFUnit &getOrigUnit() const {
     assert(OrigUnit != nullptr);
     return *OrigUnit;
#endif
   }
 
   std::optional<uint32_t> getDIEIndexForOffset(uint64_t Offset) {
     return OrigUnit->getDIEIndexForOffset(Offset);
   }
 
   /// @}
 
+  /// \defgroup Methods used for reporting warnings and errors:
+  ///
+  /// @{
+
+  void warn(const Twine &Warning, const DWARFDie *DIE = nullptr) {
+    GlobalData.warn(Warning, getUnitName(), DIE);
+  }
+
+  void warn(Error Warning, const DWARFDie *DIE = nullptr) {
+    handleAllErrors(std::move(Warning), [&](ErrorInfoBase &Info) {
+      GlobalData.warn(Info.message(), getUnitName(), DIE);
+    });
+  }
+
+  void warn(const Twine &Warning, const DWARFDebugInfoEntry *DieEntry) {
+    if (DieEntry != nullptr) {
+      DWARFDie DIE(&getOrigUnit(), DieEntry);
+      GlobalData.warn(Warning, getUnitName(), &DIE);
+      return;
+    }
+
+    GlobalData.warn(Warning, getUnitName());
+  }
+
+  void error(const Twine &Err, const DWARFDie *DIE = nullptr) {
+    GlobalData.warn(Err, getUnitName(), DIE);
+  }
+
+  void error(Error Err, const DWARFDie *DIE = nullptr) {
+    handleAllErrors(std::move(Err), [&](ErrorInfoBase &Info) {
+      GlobalData.error(Info.message(), getUnitName(), DIE);
+    });
+  }
+
+  /// @}
+
 private:
+  /// Navigate DWARF tree recursively and set die properties.
+  void analyzeDWARFStructureRec(const DWARFDebugInfoEntry *DieEntry,
+                                bool IsInModule, bool IsInFunction);
+
+  struct LinkedLocationExpressionsWithOffsetPatches {
+    DWARFLocationExpression Expression;
+    OffsetsPtrVector Patches;
+  };
+  using LinkedLocationExpressionsVector =
+      SmallVector<LinkedLocationExpressionsWithOffsetPatches>;
+
+  /// Emit debug locations.
+  void emitLocations(SectionDescriptor &DebugInfoSection,
+                     SectionDescriptor &OutLocationSection);
+
+  /// Emit location list header.
+  uint64_t emitLocListHeader(SectionDescriptor &OutLocationSection);
+
+  /// Emit location list fragment.
+  uint64_t emitLocListFragment(
+      const LinkedLocationExpressionsVector &LinkedLocationExpression,
+      SectionDescriptor &OutLocationSection);
+
+  /// Emit the .debug_addr section fragment for current unit.
+  Error emitDebugAddrSection();
+
+  /// Emit .debug_aranges.
+  void emitAranges(SectionDescriptor &DebugInfoSection,
+                   SectionDescriptor &OutArangesSection,
+                   AddressRanges &LinkedFunctionRanges);
+
+  /// Clone and emit .debug_ranges/.debug_rnglists.
+  void cloneAndEmitRangeList(SectionDescriptor &DebugInfoSection,
+                             SectionDescriptor &OutRangeSection,
+                             AddressRanges &LinkedFunctionRanges);
+
+  /// Emit range list header.
+  uint64_t emitRangeListHeader(SectionDescriptor &OutRangeSection);
+
+  /// Emit range list fragment.
+  void emitRangeListFragment(const AddressRanges &LinkedRanges,
+                             SectionDescriptor &OutRangeSection);
+
+  /// Insert the new line info sequence \p Seq into the current
+  /// set of already linked line info \p Rows.
+  void insertLineSequence(std::vector<DWARFDebugLine::Row> &Seq,
+                          std::vector<DWARFDebugLine::Row> &Rows);
+
+  /// Emits body for both macro sections.
+  void emitMacroTableImpl(const DWARFDebugMacro *MacroTable,
+                          uint64_t OffsetToMacroTable,
+                          SectionDescriptor &Section, bool hasDWARFv5Header);
+
   /// DWARFFile containing this compile unit.
-  DWARFFile &ContaingFile;
+  DWARFFile &File;
 
   /// Pointer to the paired compile unit from the input DWARF.
   DWARFUnit *OrigUnit = nullptr;
+
+  /// Line table for this unit.
+  const DWARFDebugLine::LineTable *LineTablePtr = nullptr;
+
+  /// Cached resolved paths from the line table.
+  /// The key is <UniqueUnitID, FileIdx>.
+  using ResolvedPathsMap = DenseMap<unsigned, StringEntry *>;
+  ResolvedPathsMap ResolvedFullPaths;
+  StringMap<StringEntry *> ResolvedParentPaths;
+
+  /// This field instructs compile unit to store DIE name with stripped
+  /// template parameters into the accelerator table.
+  bool CanStripTemplateName = false;
+
+  /// Address to index map.
+  DenseMap<uint64_t, uint64_t> AddrIndexMap;
+  /// Array of addresses which should be emitted into the .debug_addr section.
+  SmallVector<uint64_t> Addrs;
+
+  /// \defgroup Data Members accessed asinchroniously.
+  ///
+  /// @{
+  OffsetToUnitTy getUnitFromOffset;
+
+  std::optional<uint64_t> LowPc;
+  uint64_t HighPc = 0;
+
+  /// The ranges in that map are the PC ranges for functions in this unit,
+  /// associated with the PC offset to apply to the addresses to get
+  /// the linked address.
+  RangesTy Ranges;
+  std::mutex RangesMutex;
+
+  /// The DW_AT_low_pc of each DW_TAG_label.
+  SmallDenseMap<uint64_t, uint64_t, 1> Labels;
+  std::mutex LabelsMutex;
+
+  /// This field keeps current stage of overall compile unit processing.
+  std::atomic<Stage> Stage;
+
+  /// DIE info indexed by DIE index.
+  SmallVector<DIEInfo> DieInfoArray;
+  SmallVector<uint64_t> OutDieOffsetArray;
+  /// @}
 };
 
 } // end of namespace dwarflinker_parallel
 } // end namespace llvm
 
 #endif // LLVM_LIB_DWARFLINKERPARALLEL_DWARFLINKERCOMPILEUNIT_H

llvm/lib/DWARFLinkerParallel/DWARFLinkerCompileUnit.cpp

+//=== DWARFLinkerCompileUnit.cpp ------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "DWARFLinkerCompileUnit.h"
+#include "DIEAttributeCloner.h"
+#include "DIEGenerator.h"
+#include "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/FormatVariadic.h"
+
+using namespace llvm;
+using namespace llvm::dwarflinker_parallel;
+
+void CompileUnit::loadLineTable() {
+  LineTablePtr = File.Dwarf->getLineTableForUnit(&getOrigUnit());
+}
+
+void CompileUnit::maybeResetToLoadedStage() {
+  if (getStage() <= Stage::Loaded)
+    return;
+
+  for (DIEInfo &DieInfo : DieInfoArray)
+    DieInfo.unsetFlagsWhichSetDuringLiveAnalysis();
+
+  LowPc = std::nullopt;
+  HighPc = 0;
+  Labels.clear();
+  Ranges.clear();
+
+  if (getStage() < Stage::Cloned) {
+    setStage(Stage::Loaded);
+    return;
+  }
+
+  AbbreviationsSet.clear();
+  Abbreviations.clear();
+  OutUnitDIE = nullptr;
+  AddrIndexMap.shrink_and_clear();
+  Addrs.clear();
+
+  for (uint64_t &Offset : OutDieOffsetArray)
+    Offset = 0;
+  eraseSections();
+
+  setStage(Stage::CreatedNotLoaded);
+}
+
+bool CompileUnit::loadInputDIEs() {
+  DWARFDie InputUnitDIE = getUnitDIE(false);
+  if (!InputUnitDIE)
+    return false;
+
+  // load input dies, resize Info structures array.
+  DieInfoArray.resize(getOrigUnit().getNumDIEs());
+  OutDieOffsetArray.resize(getOrigUnit().getNumDIEs(), 0);
+  return true;
+}
+
+void CompileUnit::analyzeDWARFStructureRec(const DWARFDebugInfoEntry *DieEntry,
+                                           bool IsInModule, bool IsInFunction) {
+  for (const DWARFDebugInfoEntry *CurChild = getFirstChildEntry(DieEntry);
+       CurChild && CurChild->getAbbreviationDeclarationPtr();
+       CurChild = getSiblingEntry(CurChild)) {
+    CompileUnit::DIEInfo &ChildInfo = getDIEInfo(CurChild);
+
+    if (IsInModule)
+      ChildInfo.setIsInMouduleScope();
+    if (IsInFunction)
+      ChildInfo.setIsInFunctionScope();
+
+    switch (CurChild->getTag()) {
+    case dwarf::DW_TAG_module:
+      ChildInfo.setIsInMouduleScope();
+      if (DieEntry->getTag() == dwarf::DW_TAG_compile_unit &&
+          dwarf::toString(find(CurChild, dwarf::DW_AT_name), "") !=
+              getClangModuleName())
+        analyzeImportedModule(CurChild);
+      break;
+    case dwarf::DW_TAG_subprogram:
+      ChildInfo.setIsInFunctionScope();
+      break;
+    default:
+      break;
+    }
+
+    if (IsInModule)
+      ChildInfo.setIsInMouduleScope();
+    if (IsInFunction)
+      ChildInfo.setIsInFunctionScope();
+
+    if (CurChild->hasChildren())
+      analyzeDWARFStructureRec(CurChild, ChildInfo.getIsInMouduleScope(),
+                               ChildInfo.getIsInFunctionScope());
+  }
+}
+
+StringEntry *CompileUnit::getFileName(unsigned FileIdx,
+                                      StringPool &GlobalStrings) {
+  if (LineTablePtr) {
+    if (LineTablePtr->hasFileAtIndex(FileIdx)) {
+      // Cache the resolved paths based on the index in the line table,
+      // because calling realpath is expensive.
+      ResolvedPathsMap::const_iterator It = ResolvedFullPaths.find(FileIdx);
+      if (It == ResolvedFullPaths.end()) {
+        std::string OrigFileName;
+        bool FoundFileName = LineTablePtr->getFileNameByIndex(
+            FileIdx, getOrigUnit().getCompilationDir(),
+            DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath,
+            OrigFileName);
+        (void)FoundFileName;
+        assert(FoundFileName && "Must get file name from line table");
+
+        // Second level of caching, this time based on the file's parent
+        // path.
+        StringRef FileName = sys::path::filename(OrigFileName);
+        StringRef ParentPath = sys::path::parent_path(OrigFileName);
+
+        // If the ParentPath has not yet been resolved, resolve and cache it for
+        // future look-ups.
+        StringMap<StringEntry *>::iterator ParentIt =
+            ResolvedParentPaths.find(ParentPath);
+        if (ParentIt == ResolvedParentPaths.end()) {
+          SmallString<256> RealPath;
+          sys::fs::real_path(ParentPath, RealPath);
+          ParentIt =
+              ResolvedParentPaths
+                  .insert({ParentPath, GlobalStrings.insert(RealPath).first})
+                  .first;
+        }
+
+        // Join the file name again with the resolved path.
+        SmallString<256> ResolvedPath(ParentIt->second->first());
+        sys::path::append(ResolvedPath, FileName);
+
+        It = ResolvedFullPaths
+                 .insert(std::make_pair(
+                     FileIdx, GlobalStrings.insert(ResolvedPath).first))
+                 .first;
+      }
+
+      return It->second;
+    }
+  }
+
+  return nullptr;
+}
+
+void CompileUnit::cleanupDataAfterClonning() {
+  AbbreviationsSet.clear();
+  ResolvedFullPaths.shrink_and_clear();
+  ResolvedParentPaths.clear();
+  DieInfoArray = SmallVector<DIEInfo>();
+  OutDieOffsetArray = SmallVector<uint64_t>();
+  AddrIndexMap.shrink_and_clear();
+  getOrigUnit().clear();
+}
+
+/// Collect references to parseable Swift interfaces in imported
+/// DW_TAG_module blocks.
+void CompileUnit::analyzeImportedModule(const DWARFDebugInfoEntry *DieEntry) {
+  if (getLanguage() != dwarf::DW_LANG_Swift)
+    return;
+
+  if (!GlobalData.getOptions().ParseableSwiftInterfaces)
+    return;
+
+  StringRef Path =
+      dwarf::toStringRef(find(DieEntry, dwarf::DW_AT_LLVM_include_path));
+  if (!Path.endswith(".swiftinterface"))
+    return;
+  // Don't track interfaces that are part of the SDK.
+  StringRef SysRoot =
+      dwarf::toStringRef(find(DieEntry, dwarf::DW_AT_LLVM_sysroot));
+  if (SysRoot.empty())
+    SysRoot = getSysRoot();
+  if (!SysRoot.empty() && Path.startswith(SysRoot))
+    return;
+  if (std::optional<DWARFFormValue> Val = find(DieEntry, dwarf::DW_AT_name)) {
+    Expected<const char *> Name = Val->getAsCString();
+    if (!Name) {
+      warn(Name.takeError());
+      return;
+    }
+
+    auto &Entry = (*GlobalData.getOptions().ParseableSwiftInterfaces)[*Name];
+    // The prepend path is applied later when copying.
+    SmallString<128> ResolvedPath;
+    if (sys::path::is_relative(Path))
+      sys::path::append(
+          ResolvedPath,
+          dwarf::toString(getUnitDIE().find(dwarf::DW_AT_comp_dir), ""));
+    sys::path::append(ResolvedPath, Path);
+    if (!Entry.empty() && Entry != ResolvedPath) {
+      DWARFDie Die = getDIE(DieEntry);
+      warn(Twine("conflicting parseable interfaces for Swift Module ") + *Name +
+               ": " + Entry + " and " + Path + ".",
+           &Die);
+    }
+    Entry = std::string(ResolvedPath.str());
+  }
+}
+
+void CompileUnit::updateDieRefPatchesWithClonedOffsets() {
+  SectionDescriptor &DebugInfoSection =
+      getSectionDescriptor(DebugSectionKind::DebugInfo);
+
+  DebugInfoSection.ListDebugDieRefPatch.forEach([](DebugDieRefPatch &Patch) {
+    Patch.RefDieIdxOrClonedOffset = Patch.RefCU.getPointer()->getDieOutOffset(
+        Patch.RefDieIdxOrClonedOffset);
+  });
+
+  DebugInfoSection.ListDebugULEB128DieRefPatch.forEach(
+      [](DebugULEB128DieRefPatch &Patch) {
+        Patch.RefDieIdxOrClonedOffset =
+            Patch.RefCU.getPointer()->getDieOutOffset(
+                Patch.RefDieIdxOrClonedOffset);
+      });
+
+  SectionDescriptor &DebugLocSection =
+      getSectionDescriptor(DebugSectionKind::DebugLoc);
+
+  DebugLocSection.ListDebugULEB128DieRefPatch.forEach(
+      [](DebugULEB128DieRefPatch &Patch) {
+        Patch.RefDieIdxOrClonedOffset =
+            Patch.RefCU.getPointer()->getDieOutOffset(
+                Patch.RefDieIdxOrClonedOffset);
+      });
+
+  SectionDescriptor &DebugLocListsSection =
+      getSectionDescriptor(DebugSectionKind::DebugLocLists);
+
+  DebugLocListsSection.ListDebugULEB128DieRefPatch.forEach(
+      [](DebugULEB128DieRefPatch &Patch) {
+        Patch.RefDieIdxOrClonedOffset =
+            Patch.RefCU.getPointer()->getDieOutOffset(
+                Patch.RefDieIdxOrClonedOffset);
+      });
+}
+
+std::optional<std::pair<CompileUnit *, uint32_t>>
+CompileUnit::resolveDIEReference(const DWARFFormValue &RefValue) {
+  if (std::optional<DWARFFormValue::UnitOffset> Ref =
+          *RefValue.getAsRelativeReference()) {
+    if (Ref->Unit != nullptr) {
+      // Referenced DIE is in current compile unit.
+
+      if (std::optional<uint32_t> RefDieIdx =
+              getDIEIndexForOffset(Ref->Unit->getOffset() + Ref->Offset))
+        return std::make_pair(this, *RefDieIdx);
+    } else if (CompileUnit *RefCU = getUnitFromOffset(Ref->Offset)) {
+      // Referenced DIE is in other compile unit.
+
+      // Check whether DIEs are loaded for that compile unit.
+      enum Stage ReferredCUStage = RefCU->getStage();
+      if (ReferredCUStage < Stage::Loaded || ReferredCUStage > Stage::Cloned)
+        return std::make_pair(RefCU, 0);
+
+      if (std::optional<uint32_t> RefDieIdx =
+              RefCU->getDIEIndexForOffset(Ref->Offset))
+        return std::make_pair(RefCU, *RefDieIdx);
+    }
+  }
+
+  return std::nullopt;
+}
+
+void CompileUnit::addFunctionRange(uint64_t FuncLowPc, uint64_t FuncHighPc,
+                                   int64_t PcOffset) {
+  std::lock_guard<std::mutex> Guard(RangesMutex);
+
+  Ranges.insert({FuncLowPc, FuncHighPc}, PcOffset);
+  if (LowPc)
+    LowPc = std::min(*LowPc, FuncLowPc + PcOffset);
+  else
+    LowPc = FuncLowPc + PcOffset;
+  this->HighPc = std::max(HighPc, FuncHighPc + PcOffset);
+}
+
+void CompileUnit::addLabelLowPc(uint64_t LabelLowPc, int64_t PcOffset) {
+  std::lock_guard<std::mutex> Guard(LabelsMutex);
+  Labels.insert({LabelLowPc, PcOffset});
+}
+
+Error CompileUnit::cloneAndEmitDebugLocations() {
+  if (getGlobalData().getOptions().UpdateIndexTablesOnly)
+    return Error::success();
+
+  if (getOrigUnit().getVersion() < 5) {
+    emitLocations(getSectionDescriptor(DebugSectionKind::DebugInfo),
+                  getSectionDescriptor(DebugSectionKind::DebugLoc));
+    return Error::success();
+  }
+
+  emitLocations(getSectionDescriptor(DebugSectionKind::DebugInfo),
+                getSectionDescriptor(DebugSectionKind::DebugLocLists));
+  return Error::success();
+}
+
+void CompileUnit::emitLocations(SectionDescriptor &DebugInfoSection,
+                                SectionDescriptor &OutLocationSection) {
+  if (!DebugInfoSection.ListDebugLocPatch.empty()) {
+    DWARFUnit &OrigUnit = getOrigUnit();
+
+    uint64_t OffsetAfterUnitLength = emitLocListHeader(OutLocationSection);
+
+    DebugInfoSection.ListDebugLocPatch.forEach([&](DebugLocPatch &Patch) {
+      // Get location expressions vector corresponding to the current
+      // attribute from the source DWARF.
+      uint64_t InputDebugLocSectionOffset = DebugInfoSection.getIntVal(
+          Patch.PatchOffset,
+          DebugInfoSection.getFormParams().getDwarfOffsetByteSize());
+      Expected<DWARFLocationExpressionsVector> OriginalLocations =
+          OrigUnit.findLoclistFromOffset(InputDebugLocSectionOffset);
+
+      if (!OriginalLocations) {
+        warn(OriginalLocations.takeError());
+        return;
+      }
+
+      LinkedLocationExpressionsVector LinkedLocationExpressions;
+      for (DWARFLocationExpression &CurExpression : *OriginalLocations) {
+        LinkedLocationExpressionsWithOffsetPatches LinkedExpression;
+
+        if (CurExpression.Range) {
+          // Relocate address range.
+          LinkedExpression.Expression.Range = {
+              CurExpression.Range->LowPC + Patch.AddrAdjustmentValue,
+              CurExpression.Range->HighPC + Patch.AddrAdjustmentValue};
+        }
+
+        DataExtractor Data(CurExpression.Expr, OrigUnit.isLittleEndian(),
+                           OrigUnit.getAddressByteSize());
+
+        DWARFExpression InputExpression(Data, OrigUnit.getAddressByteSize(),
+                                        OrigUnit.getFormParams().Format);
+        cloneDieAttrExpression(InputExpression,
+                               LinkedExpression.Expression.Expr,
+                               OutLocationSection, Patch.AddrAdjustmentValue,
+                               LinkedExpression.Patches);
+
+        LinkedLocationExpressions.push_back({LinkedExpression});
+      }
+
+      // Emit locations list table fragment corresponding to the CurLocAttr.
+      DebugInfoSection.apply(Patch.PatchOffset, dwarf::DW_FORM_sec_offset,
+                             OutLocationSection.OS.tell());
+      emitLocListFragment(LinkedLocationExpressions, OutLocationSection);
+    });
+
+    if (OffsetAfterUnitLength > 0) {
+      assert(OffsetAfterUnitLength -
+                 OutLocationSection.getFormParams().getDwarfOffsetByteSize() <
+             OffsetAfterUnitLength);
+      OutLocationSection.apply(
+          OffsetAfterUnitLength -
+              OutLocationSection.getFormParams().getDwarfOffsetByteSize(),
+          dwarf::DW_FORM_sec_offset,
+          OutLocationSection.OS.tell() - OffsetAfterUnitLength);
+    }
+  }
+}
+
+/// Emit debug locations(.debug_loc, .debug_loclists) header.
+uint64_t CompileUnit::emitLocListHeader(SectionDescriptor &OutLocationSection) {
+  if (getOrigUnit().getVersion() < 5)
+    return 0;
+
+  // unit_length.
+  OutLocationSection.emitUnitLength(0xBADDEF);
+  uint64_t OffsetAfterUnitLength = OutLocationSection.OS.tell();
+
+  // Version.
+  OutLocationSection.emitIntVal(5, 2);
+
+  // Address size.
+  OutLocationSection.emitIntVal(OutLocationSection.getFormParams().AddrSize, 1);
+
+  // Seg_size
+  OutLocationSection.emitIntVal(0, 1);
+
+  // Offset entry count
+  OutLocationSection.emitIntVal(0, 4);
+
+  return OffsetAfterUnitLength;
+}
+
+/// Emit debug locations(.debug_loc, .debug_loclists) fragment.
+uint64_t CompileUnit::emitLocListFragment(
+    const LinkedLocationExpressionsVector &LinkedLocationExpression,
+    SectionDescriptor &OutLocationSection) {
+  uint64_t OffsetBeforeLocationExpression = 0;
+
+  if (getOrigUnit().getVersion() < 5) {
+    uint64_t BaseAddress = 0;
+    if (std::optional<uint64_t> LowPC = getLowPc())
+      BaseAddress = *LowPC;
+
+    for (const LinkedLocationExpressionsWithOffsetPatches &LocExpression :
+         LinkedLocationExpression) {
+      if (LocExpression.Expression.Range) {
+        OutLocationSection.emitIntVal(
+            LocExpression.Expression.Range->LowPC - BaseAddress,
+            OutLocationSection.getFormParams().AddrSize);
+        OutLocationSection.emitIntVal(
+            LocExpression.Expression.Range->HighPC - BaseAddress,
+            OutLocationSection.getFormParams().AddrSize);
+      }
+
+      OutLocationSection.emitIntVal(LocExpression.Expression.Expr.size(), 2);
+      OffsetBeforeLocationExpression = OutLocationSection.OS.tell();
+      for (uint64_t *OffsetPtr : LocExpression.Patches)
+        *OffsetPtr += OffsetBeforeLocationExpression;
+
+      OutLocationSection.OS
+          << StringRef((const char *)LocExpression.Expression.Expr.data(),
+                       LocExpression.Expression.Expr.size());
+    }
+
+    // Emit the terminator entry.
+    OutLocationSection.emitIntVal(0,
+                                  OutLocationSection.getFormParams().AddrSize);
+    OutLocationSection.emitIntVal(0,
+                                  OutLocationSection.getFormParams().AddrSize);
+    return OffsetBeforeLocationExpression;
+  }
+
+  std::optional<uint64_t> BaseAddress;
+  for (const LinkedLocationExpressionsWithOffsetPatches &LocExpression :
+       LinkedLocationExpression) {
+    if (LocExpression.Expression.Range) {
+      // Check whether base address is set. If it is not set yet
+      // then set current base address and emit base address selection entry.
+      if (!BaseAddress) {
+        BaseAddress = LocExpression.Expression.Range->LowPC;
+
+        // Emit base address.
+        OutLocationSection.emitIntVal(dwarf::DW_LLE_base_addressx, 1);
+        encodeULEB128(getAddrIndex(*BaseAddress), OutLocationSection.OS);
+      }
+
+      // Emit type of entry.
+      OutLocationSection.emitIntVal(dwarf::DW_LLE_offset_pair, 1);
+
+      // Emit start offset relative to base address.
+      encodeULEB128(LocExpression.Expression.Range->LowPC - *BaseAddress,
+                    OutLocationSection.OS);
+
+      // Emit end offset relative to base address.
+      encodeULEB128(LocExpression.Expression.Range->HighPC - *BaseAddress,
+                    OutLocationSection.OS);
+    } else
+      // Emit type of entry.
+      OutLocationSection.emitIntVal(dwarf::DW_LLE_default_location, 1);
+
+    encodeULEB128(LocExpression.Expression.Expr.size(), OutLocationSection.OS);
+    OffsetBeforeLocationExpression = OutLocationSection.OS.tell();
+    for (uint64_t *OffsetPtr : LocExpression.Patches)
+      *OffsetPtr += OffsetBeforeLocationExpression;
+
+    OutLocationSection.OS << StringRef(
+        (const char *)LocExpression.Expression.Expr.data(),
+        LocExpression.Expression.Expr.size());
+  }
+
+  // Emit the terminator entry.
+  OutLocationSection.emitIntVal(dwarf::DW_LLE_end_of_list, 1);
+  return OffsetBeforeLocationExpression;
+}
+
+Error CompileUnit::emitDebugAddrSection() {
+  if (GlobalData.getOptions().UpdateIndexTablesOnly)
+    return Error::success();
+
+  if (getVersion() < 5)
+    return Error::success();
+
+  if (Addrs.empty())
+    return Error::success();
+
+  SectionDescriptor &OutAddrSection =
+      getSectionDescriptor(DebugSectionKind::DebugAddr);
+
+  // Emit section header.
+
+  //   Emit length.
+  OutAddrSection.emitUnitLength(0xBADDEF);
+  uint64_t OffsetAfterSectionLength = OutAddrSection.OS.tell();
+
+  //   Emit version.
+  OutAddrSection.emitIntVal(5, 2);
+
+  //   Emit address size.
+  OutAddrSection.emitIntVal(getFormParams().AddrSize, 1);
+
+  //   Emit segment size.
+  OutAddrSection.emitIntVal(0, 1);
+
+  // Emit addresses.
+  for (uint64_t AddrValue : Addrs)
+    OutAddrSection.emitIntVal(AddrValue, getFormParams().AddrSize);
+
+  // Patch section length.
+  OutAddrSection.apply(
+      OffsetAfterSectionLength -
+          OutAddrSection.getFormParams().getDwarfOffsetByteSize(),
+      dwarf::DW_FORM_sec_offset,
+      OutAddrSection.OS.tell() - OffsetAfterSectionLength);
+
+  return Error::success();
+}
+
+Error CompileUnit::cloneAndEmitRanges() {
+  if (getGlobalData().getOptions().UpdateIndexTablesOnly)
+    return Error::success();
+
+  // Build set of linked address ranges for unit function ranges.
+  AddressRanges LinkedFunctionRanges;
+  for (const AddressRangeValuePair &Range : getFunctionRanges())
+    LinkedFunctionRanges.insert(
+        {Range.Range.start() + Range.Value, Range.Range.end() + Range.Value});
+
+  emitAranges(getSectionDescriptor(DebugSectionKind::DebugInfo),
+              getSectionDescriptor(DebugSectionKind::DebugARanges),
+              LinkedFunctionRanges);
+
+  if (getOrigUnit().getVersion() < 5) {
+    cloneAndEmitRangeList(getSectionDescriptor(DebugSectionKind::DebugInfo),
+                          getSectionDescriptor(DebugSectionKind::DebugRange),
+                          LinkedFunctionRanges);
+    return Error::success();
+  }
+
+  cloneAndEmitRangeList(getSectionDescriptor(DebugSectionKind::DebugInfo),
+                        getSectionDescriptor(DebugSectionKind::DebugRngLists),
+                        LinkedFunctionRanges);
+  return Error::success();
+}
+
+void CompileUnit::cloneAndEmitRangeList(SectionDescriptor &DebugInfoSection,
+                                        SectionDescriptor &OutRangeSection,
+                                        AddressRanges &LinkedFunctionRanges) {
+  if (!DebugInfoSection.ListDebugRangePatch.empty()) {
+    std::optional<AddressRangeValuePair> CachedRange;
+    uint64_t OffsetAfterUnitLength = emitRangeListHeader(OutRangeSection);
+
+    DebugRangePatch *CompileUnitRangePtr = nullptr;
+    DebugInfoSection.ListDebugRangePatch.forEach([&](DebugRangePatch &Patch) {
+      if (Patch.IsCompileUnitRanges) {
+        CompileUnitRangePtr = &Patch;
+      } else {
+        // Get ranges from the source DWARF corresponding to the current
+        // attribute.
+        AddressRanges LinkedRanges;
+        uint64_t InputDebugRangesSectionOffset = DebugInfoSection.getIntVal(
+            Patch.PatchOffset,
+            DebugInfoSection.getFormParams().getDwarfOffsetByteSize());
+        if (Expected<DWARFAddressRangesVector> InputRanges =
+                getOrigUnit().findRnglistFromOffset(
+                    InputDebugRangesSectionOffset)) {
+          // Apply relocation adjustment.
+          for (const auto &Range : *InputRanges) {
+            if (!CachedRange || !CachedRange->Range.contains(Range.LowPC))
+              CachedRange =
+                  getFunctionRanges().getRangeThatContains(Range.LowPC);
+
+            // All range entries should lie in the function range.
+            if (!CachedRange) {
+              warn("inconsistent range data.");
+              continue;
+            }
+
+            // Store range for emiting.
+            LinkedRanges.insert({Range.LowPC + CachedRange->Value,
+                                 Range.HighPC + CachedRange->Value});
+          }
+        } else {
+          llvm::consumeError(InputRanges.takeError());
+          warn("invalid range list ignored.");
+        }
+
+        // Emit linked ranges.
+        DebugInfoSection.apply(Patch.PatchOffset, dwarf::DW_FORM_sec_offset,
+                               OutRangeSection.OS.tell());
+        emitRangeListFragment(LinkedRanges, OutRangeSection);
+      }
+    });
+
+    if (CompileUnitRangePtr != nullptr) {
+      // Emit compile unit ranges last to be binary compatible with classic
+      // dsymutil.
+      DebugInfoSection.apply(CompileUnitRangePtr->PatchOffset,
+                             dwarf::DW_FORM_sec_offset,
+                             OutRangeSection.OS.tell());
+      emitRangeListFragment(LinkedFunctionRanges, OutRangeSection);
+    }
+
+    if (OffsetAfterUnitLength > 0) {
+      assert(OffsetAfterUnitLength -
+                 OutRangeSection.getFormParams().getDwarfOffsetByteSize() <
+             OffsetAfterUnitLength);
+      OutRangeSection.apply(
+          OffsetAfterUnitLength -
+              OutRangeSection.getFormParams().getDwarfOffsetByteSize(),
+          dwarf::DW_FORM_sec_offset,
+          OutRangeSection.OS.tell() - OffsetAfterUnitLength);
+    }
+  }
+}
+
+uint64_t CompileUnit::emitRangeListHeader(SectionDescriptor &OutRangeSection) {
+  if (OutRangeSection.getFormParams().Version < 5)
+    return 0;
+
+  // unit_length.
+  OutRangeSection.emitUnitLength(0xBADDEF);
+  uint64_t OffsetAfterUnitLength = OutRangeSection.OS.tell();
+
+  // Version.
+  OutRangeSection.emitIntVal(5, 2);
+
+  // Address size.
+  OutRangeSection.emitIntVal(OutRangeSection.getFormParams().AddrSize, 1);
+
+  // Seg_size
+  OutRangeSection.emitIntVal(0, 1);
+
+  // Offset entry count
+  OutRangeSection.emitIntVal(0, 4);
+
+  return OffsetAfterUnitLength;
+}
+
+void CompileUnit::emitRangeListFragment(const AddressRanges &LinkedRanges,
+                                        SectionDescriptor &OutRangeSection) {
+  if (OutRangeSection.getFormParams().Version < 5) {
+    // Emit ranges.
+    uint64_t BaseAddress = 0;
+    if (std::optional<uint64_t> LowPC = getLowPc())
+      BaseAddress = *LowPC;
+
+    for (const AddressRange &Range : LinkedRanges) {
+      OutRangeSection.emitIntVal(Range.start() - BaseAddress,
+                                 OutRangeSection.getFormParams().AddrSize);
+      OutRangeSection.emitIntVal(Range.end() - BaseAddress,
+                                 OutRangeSection.getFormParams().AddrSize);
+    }
+
+    // Add the terminator entry.
+    OutRangeSection.emitIntVal(0, OutRangeSection.getFormParams().AddrSize);
+    OutRangeSection.emitIntVal(0, OutRangeSection.getFormParams().AddrSize);
+    return;
+  }
+
+  std::optional<uint64_t> BaseAddress;
+  for (const AddressRange &Range : LinkedRanges) {
+    if (!BaseAddress) {
+      BaseAddress = Range.start();
+
+      // Emit base address.
+      OutRangeSection.emitIntVal(dwarf::DW_RLE_base_addressx, 1);
+      encodeULEB128(getAddrIndex(*BaseAddress), OutRangeSection.OS);
+    }
+
+    // Emit type of entry.
+    OutRangeSection.emitIntVal(dwarf::DW_RLE_offset_pair, 1);
+
+    // Emit start offset relative to base address.
+    encodeULEB128(Range.start() - *BaseAddress, OutRangeSection.OS);
+
+    // Emit end offset relative to base address.
+    encodeULEB128(Range.end() - *BaseAddress, OutRangeSection.OS);
+  }
+
+  // Emit the terminator entry.
+  OutRangeSection.emitIntVal(dwarf::DW_RLE_end_of_list, 1);
+}
+
+void CompileUnit::emitAranges(SectionDescriptor &DebugInfoSection,
+                              SectionDescriptor &OutArangesSection,
+                              AddressRanges &LinkedFunctionRanges) {
+  if (LinkedFunctionRanges.empty())
+    return;
+
+  // Emit Header.
+  unsigned HeaderSize =
+      sizeof(int32_t) + // Size of contents (w/o this field
+      sizeof(int16_t) + // DWARF ARange version number
+      sizeof(int32_t) + // Offset of CU in the .debug_info section
+      sizeof(int8_t) +  // Pointer Size (in bytes)
+      sizeof(int8_t);   // Segment Size (in bytes)
+
+  unsigned TupleSize = OutArangesSection.getFormParams().AddrSize * 2;
+  unsigned Padding = offsetToAlignment(HeaderSize, Align(TupleSize));
+
+  OutArangesSection.emitOffset(0xBADDEF); // Aranges length
+  uint64_t OffsetAfterArangesLengthField = OutArangesSection.OS.tell();
+
+  OutArangesSection.emitIntVal(dwarf::DW_ARANGES_VERSION, 2); // Version number
+  OutArangesSection.notePatch(
+      DebugOffsetPatch{OutArangesSection.OS.tell(), &DebugInfoSection});
+  OutArangesSection.emitOffset(0xBADDEF); // Corresponding unit's offset
+  OutArangesSection.emitIntVal(OutArangesSection.getFormParams().AddrSize,
+                               1);    // Address size
+  OutArangesSection.emitIntVal(0, 1); // Segment size
+
+  for (size_t Idx = 0; Idx < Padding; Idx++)
+    OutArangesSection.emitIntVal(0, 1); // Padding
+
+  // Emit linked ranges.
+  for (const AddressRange &Range : LinkedFunctionRanges) {
+    OutArangesSection.emitIntVal(Range.start(),
+                                 OutArangesSection.getFormParams().AddrSize);
+    OutArangesSection.emitIntVal(Range.end() - Range.start(),
+                                 OutArangesSection.getFormParams().AddrSize);
+  }
+
+  // Emit terminator.
+  OutArangesSection.emitIntVal(0, OutArangesSection.getFormParams().AddrSize);
+  OutArangesSection.emitIntVal(0, OutArangesSection.getFormParams().AddrSize);
+
+  uint64_t OffsetAfterArangesEnd = OutArangesSection.OS.tell();
+
+  // Update Aranges lentgh.
+  OutArangesSection.apply(
+      OffsetAfterArangesLengthField -
+          OutArangesSection.getFormParams().getDwarfOffsetByteSize(),
+      dwarf::DW_FORM_sec_offset,
+      OffsetAfterArangesEnd - OffsetAfterArangesLengthField);
+}
+
+Error CompileUnit::cloneAndEmitDebugMacro() {
+  if (getOutUnitDIE() == nullptr)
+    return Error::success();
+
+  DWARFUnit &OrigUnit = getOrigUnit();
+  DWARFDie OrigUnitDie = OrigUnit.getUnitDIE();
+
+  // Check for .debug_macro table.
+  if (std::optional<uint64_t> MacroAttr =
+          dwarf::toSectionOffset(OrigUnitDie.find(dwarf::DW_AT_macros))) {
+    if (const DWARFDebugMacro *Table =
+            getContaingFile().Dwarf->getDebugMacro()) {
+      SectionDescriptor &OutSection =
+          getSectionDescriptor(DebugSectionKind::DebugMacro);
+      emitMacroTableImpl(Table, *MacroAttr, OutSection, true);
+    }
+  }
+
+  // Check for .debug_macinfo table.
+  if (std::optional<uint64_t> MacroAttr =
+          dwarf::toSectionOffset(OrigUnitDie.find(dwarf::DW_AT_macro_info))) {
+    if (const DWARFDebugMacro *Table =
+            getContaingFile().Dwarf->getDebugMacinfo()) {
+      SectionDescriptor &OutSection =
+          getSectionDescriptor(DebugSectionKind::DebugMacinfo);
+      emitMacroTableImpl(Table, *MacroAttr, OutSection, false);
+    }
+  }
+
+  return Error::success();
+}
+
+void CompileUnit::emitMacroTableImpl(const DWARFDebugMacro *MacroTable,
+                                     uint64_t OffsetToMacroTable,
+                                     SectionDescriptor &Section,
+                                     bool hasDWARFv5Header) {
+  bool DefAttributeIsReported = false;
+  bool UndefAttributeIsReported = false;
+  bool ImportAttributeIsReported = false;
+
+  for (const DWARFDebugMacro::MacroList &List : MacroTable->MacroLists) {
+    if (OffsetToMacroTable == List.Offset) {
+      // Write DWARFv5 header.
+      if (hasDWARFv5Header) {
+        // Write header version.
+        Section.emitIntVal(List.Header.Version, sizeof(List.Header.Version));
+
+        uint8_t Flags = List.Header.Flags;
+
+        // Check for OPCODE_OPERANDS_TABLE.
+        if (Flags &
+            DWARFDebugMacro::HeaderFlagMask::MACRO_OPCODE_OPERANDS_TABLE) {
+          Flags &=
+              ~DWARFDebugMacro::HeaderFlagMask::MACRO_OPCODE_OPERANDS_TABLE;
+          warn("opcode_operands_table is not supported yet.");
+        }
+
+        // Check for DEBUG_LINE_OFFSET.
+        std::optional<uint64_t> StmtListOffset;
+        if (Flags & DWARFDebugMacro::HeaderFlagMask::MACRO_DEBUG_LINE_OFFSET) {
+          // Get offset to the line table from the cloned compile unit.
+          for (auto &V : getOutUnitDIE()->values()) {
+            if (V.getAttribute() == dwarf::DW_AT_stmt_list) {
+              StmtListOffset = V.getDIEInteger().getValue();
+              break;
+            }
+          }
+
+          if (!StmtListOffset) {
+            Flags &= ~DWARFDebugMacro::HeaderFlagMask::MACRO_DEBUG_LINE_OFFSET;
+            warn("couldn`t find line table for macro table.");
+          }
+        }
+
+        // Write flags.
+        Section.emitIntVal(Flags, sizeof(Flags));
+
+        // Write offset to line table.
+        if (StmtListOffset) {
+          Section.notePatch(DebugOffsetPatch{
+              Section.OS.tell(),
+              &getSectionDescriptor(DebugSectionKind::DebugLine)});
+          // TODO: check that List.Header.getOffsetByteSize() and
+          // DebugOffsetPatch agree on size.
+          Section.emitIntVal(0xBADDEF, List.Header.getOffsetByteSize());
+        }
+      }
+
+      // Write macro entries.
+      for (const DWARFDebugMacro::Entry &MacroEntry : List.Macros) {
+        if (MacroEntry.Type == 0) {
+          encodeULEB128(MacroEntry.Type, Section.OS);
+          continue;
+        }
+
+        uint8_t MacroType = MacroEntry.Type;
+        switch (MacroType) {
+        default: {
+          bool HasVendorSpecificExtension =
+              (!hasDWARFv5Header &&
+               MacroType == dwarf::DW_MACINFO_vendor_ext) ||
+              (hasDWARFv5Header && (MacroType >= dwarf::DW_MACRO_lo_user &&
+                                    MacroType <= dwarf::DW_MACRO_hi_user));
+
+          if (HasVendorSpecificExtension) {
+            // Write macinfo type.
+            Section.emitIntVal(MacroType, 1);
+
+            // Write vendor extension constant.
+            encodeULEB128(MacroEntry.ExtConstant, Section.OS);
+
+            // Write vendor extension string.
+            Section.emitString(dwarf::DW_FORM_string, MacroEntry.ExtStr);
+          } else
+            warn("unknown macro type. skip.");
+        } break;
+        // debug_macro and debug_macinfo share some common encodings.
+        // DW_MACRO_define     == DW_MACINFO_define
+        // DW_MACRO_undef      == DW_MACINFO_undef
+        // DW_MACRO_start_file == DW_MACINFO_start_file
+        // DW_MACRO_end_file   == DW_MACINFO_end_file
+        // For readibility/uniformity we are using DW_MACRO_*.
+        case dwarf::DW_MACRO_define:
+        case dwarf::DW_MACRO_undef: {
+          // Write macinfo type.
+          Section.emitIntVal(MacroType, 1);
+
+          // Write source line.
+          encodeULEB128(MacroEntry.Line, Section.OS);
+
+          // Write macro string.
+          Section.emitString(dwarf::DW_FORM_string, MacroEntry.MacroStr);
+        } break;
+        case dwarf::DW_MACRO_define_strp:
+        case dwarf::DW_MACRO_undef_strp:
+        case dwarf::DW_MACRO_define_strx:
+        case dwarf::DW_MACRO_undef_strx: {
+          // DW_MACRO_*_strx forms are not supported currently.
+          // Convert to *_strp.
+          switch (MacroType) {
+          case dwarf::DW_MACRO_define_strx: {
+            MacroType = dwarf::DW_MACRO_define_strp;
+            if (!DefAttributeIsReported) {
+              warn("DW_MACRO_define_strx unsupported yet. Convert to "
+                   "DW_MACRO_define_strp.");
+              DefAttributeIsReported = true;
+            }
+          } break;
+          case dwarf::DW_MACRO_undef_strx: {
+            MacroType = dwarf::DW_MACRO_undef_strp;
+            if (!UndefAttributeIsReported) {
+              warn("DW_MACRO_undef_strx unsupported yet. Convert to "
+                   "DW_MACRO_undef_strp.");
+              UndefAttributeIsReported = true;
+            }
+          } break;
+          default:
+            // Nothing to do.
+            break;
+          }
+
+          // Write macinfo type.
+          Section.emitIntVal(MacroType, 1);
+
+          // Write source line.
+          encodeULEB128(MacroEntry.Line, Section.OS);
+
+          // Write macro string.
+          Section.emitString(dwarf::DW_FORM_strp, MacroEntry.MacroStr);
+          break;
+        }
+        case dwarf::DW_MACRO_start_file: {
+          // Write macinfo type.
+          Section.emitIntVal(MacroType, 1);
+          // Write source line.
+          encodeULEB128(MacroEntry.Line, Section.OS);
+          // Write source file id.
+          encodeULEB128(MacroEntry.File, Section.OS);
+        } break;
+        case dwarf::DW_MACRO_end_file: {
+          // Write macinfo type.
+          Section.emitIntVal(MacroType, 1);
+        } break;
+        case dwarf::DW_MACRO_import:
+        case dwarf::DW_MACRO_import_sup: {
+          if (!ImportAttributeIsReported) {
+            warn("DW_MACRO_import and DW_MACRO_import_sup are unsupported "
+                 "yet. remove.");
+            ImportAttributeIsReported = true;
+          }
+        } break;
+        }
+      }
+
+      return;
+    }
+  }
+}
+
+void CompileUnit::cloneDieAttrExpression(
+    const DWARFExpression &InputExpression,
+    SmallVectorImpl<uint8_t> &OutputExpression, SectionDescriptor &Section,
+    std::optional<int64_t> VarAddressAdjustment,
+    OffsetsPtrVector &PatchesOffsets) {
+  using Encoding = DWARFExpression::Operation::Encoding;
+
+  DWARFUnit &OrigUnit = getOrigUnit();
+  uint8_t OrigAddressByteSize = OrigUnit.getAddressByteSize();
+
+  uint64_t OpOffset = 0;
+  for (auto &Op : InputExpression) {
+    auto Desc = Op.getDescription();
+    // DW_OP_const_type is variable-length and has 3
+    // operands. Thus far we only support 2.
+    if ((Desc.Op.size() == 2 && Desc.Op[0] == Encoding::BaseTypeRef) ||
+        (Desc.Op.size() == 2 && Desc.Op[1] == Encoding::BaseTypeRef &&
+         Desc.Op[0] != Encoding::Size1))
+      warn("unsupported DW_OP encoding.");
+
+    if ((Desc.Op.size() == 1 && Desc.Op[0] == Encoding::BaseTypeRef) ||
+        (Desc.Op.size() == 2 && Desc.Op[1] == Encoding::BaseTypeRef &&
+         Desc.Op[0] == Encoding::Size1)) {
+      // This code assumes that the other non-typeref operand fits into 1 byte.
+      assert(OpOffset < Op.getEndOffset());
+      uint32_t ULEBsize = Op.getEndOffset() - OpOffset - 1;
+      assert(ULEBsize <= 16);
+
+      // Copy over the operation.
+      assert(!Op.getSubCode() && "SubOps not yet supported");
+      OutputExpression.push_back(Op.getCode());
+      uint64_t RefOffset;
+      if (Desc.Op.size() == 1) {
+        RefOffset = Op.getRawOperand(0);
+      } else {
+        OutputExpression.push_back(Op.getRawOperand(0));
+        RefOffset = Op.getRawOperand(1);
+      }
+      uint8_t ULEB[16];
+      uint32_t Offset = 0;
+      unsigned RealSize = 0;
+      // Look up the base type. For DW_OP_convert, the operand may be 0 to
+      // instead indicate the generic type. The same holds for
+      // DW_OP_reinterpret, which is currently not supported.
+      if (RefOffset > 0 || Op.getCode() != dwarf::DW_OP_convert) {
+        RefOffset += OrigUnit.getOffset();
+        uint32_t RefDieIdx = 0;
+        if (std::optional<uint32_t> Idx =
+                OrigUnit.getDIEIndexForOffset(RefOffset))
+          RefDieIdx = *Idx;
+
+        // Use fixed size for ULEB128 data, since we need to update that size
+        // later with the proper offsets. Use 5 for DWARF32, 9 for DWARF64.
+        ULEBsize = getFormParams().getDwarfOffsetByteSize() + 1;
+
+        RealSize = encodeULEB128(0xBADDEF, ULEB, ULEBsize);
+
+        Section.notePatchWithOffsetUpdate(
+            DebugULEB128DieRefPatch(OutputExpression.size(), this, this,
+                                    RefDieIdx),
+            PatchesOffsets);
+      } else
+        RealSize = encodeULEB128(Offset, ULEB, ULEBsize);
+
+      if (RealSize > ULEBsize) {
+        // Emit the generic type as a fallback.
+        RealSize = encodeULEB128(0, ULEB, ULEBsize);
+        warn("base type ref doesn't fit.");
+      }
+      assert(RealSize == ULEBsize && "padding failed");
+      ArrayRef<uint8_t> ULEBbytes(ULEB, ULEBsize);
+      OutputExpression.append(ULEBbytes.begin(), ULEBbytes.end());
+    } else if (!getGlobalData().getOptions().UpdateIndexTablesOnly &&
+               Op.getCode() == dwarf::DW_OP_addrx) {
+      if (std::optional<object::SectionedAddress> SA =
+              OrigUnit.getAddrOffsetSectionItem(Op.getRawOperand(0))) {
+        // DWARFLinker does not use addrx forms since it generates relocated
+        // addresses. Replace DW_OP_addrx with DW_OP_addr here.
+        // Argument of DW_OP_addrx should be relocated here as it is not
+        // processed by applyValidRelocs.
+        OutputExpression.push_back(dwarf::DW_OP_addr);
+        uint64_t LinkedAddress =
+            SA->Address + (VarAddressAdjustment ? *VarAddressAdjustment : 0);
+        if ((getEndianness() == support::endianness::little) !=
+            sys::IsLittleEndianHost)
+          sys::swapByteOrder(LinkedAddress);
+        ArrayRef<uint8_t> AddressBytes(
+            reinterpret_cast<const uint8_t *>(&LinkedAddress),
+            OrigAddressByteSize);
+        OutputExpression.append(AddressBytes.begin(), AddressBytes.end());
+      } else
+        warn("cann't read DW_OP_addrx operand.");
+    } else if (!getGlobalData().getOptions().UpdateIndexTablesOnly &&
+               Op.getCode() == dwarf::DW_OP_constx) {
+      if (std::optional<object::SectionedAddress> SA =
+              OrigUnit.getAddrOffsetSectionItem(Op.getRawOperand(0))) {
+        // DWARFLinker does not use constx forms since it generates relocated
+        // addresses. Replace DW_OP_constx with DW_OP_const[*]u here.
+        // Argument of DW_OP_constx should be relocated here as it is not
+        // processed by applyValidRelocs.
+        std::optional<uint8_t> OutOperandKind;
+        switch (OrigAddressByteSize) {
+        case 2:
+          OutOperandKind = dwarf::DW_OP_const2u;
+          break;
+        case 4:
+          OutOperandKind = dwarf::DW_OP_const4u;
+          break;
+        case 8:
+          OutOperandKind = dwarf::DW_OP_const8u;
+          break;
+        default:
+          warn(
+              formatv(("unsupported address size: {0}."), OrigAddressByteSize));
+          break;
+        }
+
+        if (OutOperandKind) {
+          OutputExpression.push_back(*OutOperandKind);
+          uint64_t LinkedAddress =
+              SA->Address + (VarAddressAdjustment ? *VarAddressAdjustment : 0);
+          if ((getEndianness() == support::endianness::little) !=
+              sys::IsLittleEndianHost)
+            sys::swapByteOrder(LinkedAddress);
+          ArrayRef<uint8_t> AddressBytes(
+              reinterpret_cast<const uint8_t *>(&LinkedAddress),
+              OrigAddressByteSize);
+          OutputExpression.append(AddressBytes.begin(), AddressBytes.end());
+        }
+      } else
+        warn("cann't read DW_OP_constx operand.");
+    } else {
+      // Copy over everything else unmodified.
+      StringRef Bytes =
+          InputExpression.getData().slice(OpOffset, Op.getEndOffset());
+      OutputExpression.append(Bytes.begin(), Bytes.end());
+    }
+    OpOffset = Op.getEndOffset();
+  }
+}
+
+Error CompileUnit::cloneAndEmit(std::optional<Triple> TargetTriple) {
+  BumpPtrAllocator Allocator;
+
+  DWARFDie OrigUnitDIE = getOrigUnit().getUnitDIE();
+  if (!OrigUnitDIE.isValid())
+    return Error::success();
+
+  CanStripTemplateName =
+      llvm::is_contained(getGlobalData().getOptions().AccelTables,
+                         DWARFLinker::AccelTableKind::Apple);
+
+  // Clone input DIE entry recursively.
+  DIE *OutCUDie = cloneDIE(OrigUnitDIE.getDebugInfoEntry(), getHeaderSize(),
+                           std::nullopt, std::nullopt, Allocator);
+  setOutUnitDIE(OutCUDie);
+
+  if (getGlobalData().getOptions().NoOutput || (OutCUDie == nullptr))
+    return Error::success();
+
+  assert(TargetTriple.has_value());
+  if (Error Err = cloneAndEmitLineTable(*TargetTriple))
+    return Err;
+
+  if (Error Err = cloneAndEmitDebugMacro())
+    return Err;
+
+  if (Error Err = emitDebugInfo(*TargetTriple))
+    return Err;
+
+  // ASSUMPTION: .debug_info section should already be emitted at this point.
+  // cloneAndEmitRanges & cloneAndEmitDebugLocations use .debug_info section
+  // data.
+
+  if (Error Err = cloneAndEmitRanges())
+    return Err;
+
+  if (Error Err = cloneAndEmitDebugLocations())
+    return Err;
+
+  if (Error Err = emitDebugAddrSection())
+    return Err;
+
+  return emitAbbreviations();
+}
+
+bool needToClone(CompileUnit::DIEInfo &Info) {
+  return Info.getKeep() || Info.getKeepChildren();
+}
+
+DIE *CompileUnit::cloneDIE(const DWARFDebugInfoEntry *InputDieEntry,
+                           uint64_t OutOffset,
+                           std::optional<int64_t> FuncAddressAdjustment,
+                           std::optional<int64_t> VarAddressAdjustment,
+                           BumpPtrAllocator &Allocator) {
+  uint32_t InputDieIdx = getDIEIndex(InputDieEntry);
+  CompileUnit::DIEInfo &Info = getDIEInfo(InputDieIdx);
+
+  if (!needToClone(Info))
+    return nullptr;
+
+  bool HasLocationExpressionAddress = false;
+  if (InputDieEntry->getTag() == dwarf::DW_TAG_subprogram) {
+    // Get relocation adjustment value for the current function.
+    FuncAddressAdjustment =
+        getContaingFile().Addresses->getSubprogramRelocAdjustment(
+            getDIE(InputDieEntry));
+  } else if (InputDieEntry->getTag() == dwarf::DW_TAG_variable) {
+    // Get relocation adjustment value for the current variable.
+    std::pair<bool, std::optional<int64_t>> LocExprAddrAndRelocAdjustment =
+        getContaingFile().Addresses->getVariableRelocAdjustment(
+            getDIE(InputDieEntry));
+
+    HasLocationExpressionAddress = LocExprAddrAndRelocAdjustment.first;
+    if (LocExprAddrAndRelocAdjustment.first &&
+        LocExprAddrAndRelocAdjustment.second)
+      VarAddressAdjustment = *LocExprAddrAndRelocAdjustment.second;
+  }
+
+  DIEGenerator DIEGenerator(Allocator, *this);
+  DIE *ClonedDIE = DIEGenerator.createDIE(InputDieEntry->getTag(), OutOffset);
+  rememberDieOutOffset(InputDieIdx, OutOffset);
+
+  // Clone Attributes.
+  DIEAttributeCloner AttributesCloner(
+      ClonedDIE, *this, InputDieEntry, DIEGenerator, FuncAddressAdjustment,
+      VarAddressAdjustment, HasLocationExpressionAddress);
+  AttributesCloner.clone();
+
+  bool HasChildrenToClone = Info.getKeepChildren();
+  OutOffset = AttributesCloner.finalizeAbbreviations(HasChildrenToClone);
+
+  if (HasChildrenToClone) {
+    // Recursively clone children.
+    for (const DWARFDebugInfoEntry *CurChild =
+             getFirstChildEntry(InputDieEntry);
+         CurChild && CurChild->getAbbreviationDeclarationPtr();
+         CurChild = getSiblingEntry(CurChild)) {
+      if (DIE *ClonedChild =
+              cloneDIE(CurChild, OutOffset, FuncAddressAdjustment,
+                       VarAddressAdjustment, Allocator)) {
+        OutOffset = ClonedChild->getOffset() + ClonedChild->getSize();
+        DIEGenerator.addChild(ClonedChild);
+      }
+    }
+
+    // Account for the end of children marker.
+    OutOffset += sizeof(int8_t);
+  }
+
+  // Update our size.
+  ClonedDIE->setSize(OutOffset - ClonedDIE->getOffset());
+  return ClonedDIE;
+}
+
+Error CompileUnit::cloneAndEmitLineTable(Triple &TargetTriple) {
+  const DWARFDebugLine::LineTable *InputLineTable =
+      getContaingFile().Dwarf->getLineTableForUnit(&getOrigUnit());
+  if (InputLineTable == nullptr) {
+    warn("cann't load line table.");
+    return Error::success();
+  }
+
+  DWARFDebugLine::LineTable OutLineTable;
+
+  // Set Line Table header.
+  OutLineTable.Prologue = InputLineTable->Prologue;
+  OutLineTable.Prologue.FormParams.AddrSize = getFormParams().AddrSize;
+
+  // Set Line Table Rows.
+  if (getGlobalData().getOptions().UpdateIndexTablesOnly) {
+    OutLineTable.Rows = InputLineTable->Rows;
+    // If all the line table contains is a DW_LNE_end_sequence, clear the line
+    // table rows, it will be inserted again in the DWARFStreamer.
+    if (OutLineTable.Rows.size() == 1 && OutLineTable.Rows[0].EndSequence)
+      OutLineTable.Rows.clear();
+
+    OutLineTable.Sequences = InputLineTable->Sequences;
+  } else {
+    // This vector is the output line table.
+    std::vector<DWARFDebugLine::Row> NewRows;
+    NewRows.reserve(InputLineTable->Rows.size());
+
+    // Current sequence of rows being extracted, before being inserted
+    // in NewRows.
+    std::vector<DWARFDebugLine::Row> Seq;
+
+    const auto &FunctionRanges = getFunctionRanges();
+    std::optional<AddressRangeValuePair> CurrRange;
+
+    // FIXME: This logic is meant to generate exactly the same output as
+    // Darwin's classic dsymutil. There is a nicer way to implement this
+    // by simply putting all the relocated line info in NewRows and simply
+    // sorting NewRows before passing it to emitLineTableForUnit. This
+    // should be correct as sequences for a function should stay
+    // together in the sorted output. There are a few corner cases that
+    // look suspicious though, and that required to implement the logic
+    // this way. Revisit that once initial validation is finished.
+
+    // Iterate over the object file line info and extract the sequences
+    // that correspond to linked functions.
+    for (DWARFDebugLine::Row Row : InputLineTable->Rows) {
+      // Check whether we stepped out of the range. The range is
+      // half-open, but consider accept the end address of the range if
+      // it is marked as end_sequence in the input (because in that
+      // case, the relocation offset is accurate and that entry won't
+      // serve as the start of another function).
+      if (!CurrRange || !CurrRange->Range.contains(Row.Address.Address)) {
+        // We just stepped out of a known range. Insert a end_sequence
+        // corresponding to the end of the range.
+        uint64_t StopAddress =
+            CurrRange ? CurrRange->Range.end() + CurrRange->Value : -1ULL;
+        CurrRange = FunctionRanges.getRangeThatContains(Row.Address.Address);
+        if (StopAddress != -1ULL && !Seq.empty()) {
+          // Insert end sequence row with the computed end address, but
+          // the same line as the previous one.
+          auto NextLine = Seq.back();
+          NextLine.Address.Address = StopAddress;
+          NextLine.EndSequence = 1;
+          NextLine.PrologueEnd = 0;
+          NextLine.BasicBlock = 0;
+          NextLine.EpilogueBegin = 0;
+          Seq.push_back(NextLine);
+          insertLineSequence(Seq, NewRows);
+        }
+
+        if (!CurrRange)
+          continue;
+      }
+
+      // Ignore empty sequences.
+      if (Row.EndSequence && Seq.empty())
+        continue;
+
+      // Relocate row address and add it to the current sequence.
+      Row.Address.Address += CurrRange->Value;
+      Seq.emplace_back(Row);
+
+      if (Row.EndSequence)
+        insertLineSequence(Seq, NewRows);
+    }
+
+    OutLineTable.Rows = std::move(NewRows);
+  }
+
+  return emitDebugLine(TargetTriple, OutLineTable);
+}
+
+void CompileUnit::insertLineSequence(std::vector<DWARFDebugLine::Row> &Seq,
+                                     std::vector<DWARFDebugLine::Row> &Rows) {
+  if (Seq.empty())
+    return;
+
+  if (!Rows.empty() && Rows.back().Address < Seq.front().Address) {
+    llvm::append_range(Rows, Seq);
+    Seq.clear();
+    return;
+  }
+
+  object::SectionedAddress Front = Seq.front().Address;
+  auto InsertPoint = partition_point(
+      Rows, [=](const DWARFDebugLine::Row &O) { return O.Address < Front; });
+
+  // FIXME: this only removes the unneeded end_sequence if the
+  // sequences have been inserted in order. Using a global sort like
+  // described in cloneAndEmitLineTable() and delaying the end_sequene
+  // elimination to DebugLineEmitter::emit() we can get rid of all of them.
+  if (InsertPoint != Rows.end() && InsertPoint->Address == Front &&
+      InsertPoint->EndSequence) {
+    *InsertPoint = Seq.front();
+    Rows.insert(InsertPoint + 1, Seq.begin() + 1, Seq.end());
+  } else {
+    Rows.insert(InsertPoint, Seq.begin(), Seq.end());
+  }
+
+  Seq.clear();
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+LLVM_DUMP_METHOD void CompileUnit::DIEInfo::dump() {
+  llvm::errs() << "{\n";
+  llvm::errs() << "  Placement: ";
+  switch (getPlacement()) {
+  case NotSet:
+    llvm::errs() << "NotSet\n";
+    break;
+  case TypeTable:
+    llvm::errs() << "TypeTable\n";
+    break;
+  case PlainDwarf:
+    llvm::errs() << "PlainDwarf\n";
+    break;
+  case Both:
+    llvm::errs() << "Both\n";
+    break;
+  case Parent:
+    llvm::errs() << "Parent\n";
+    break;
+  }
+
+  llvm::errs() << "  Keep: " << getKeep();
+  llvm::errs() << "  KeepChildren: " << getKeepChildren();
+  llvm::errs() << "  ReferrencedBy: " << getReferrencedBy();
+  llvm::errs() << "  IsInMouduleScope: " << getIsInMouduleScope();
+  llvm::errs() << "  IsInFunctionScope: " << getIsInFunctionScope();
+  llvm::errs() << "}\n";
+}
+#endif // if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)

llvm/lib/DWARFLinkerParallel/DWARFLinkerGlobalData.h

+//===- DWARFLinkerGlobalData.h ----------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_DWARFLINKERPARALLEL_DWARFLINKERGLOBALDATA_H
+#define LLVM_LIB_DWARFLINKERPARALLEL_DWARFLINKERGLOBALDATA_H
+
+#include "llvm/DWARFLinkerParallel/DWARFLinker.h"
+#include "llvm/DWARFLinkerParallel/StringPool.h"
+#include "llvm/Support/PerThreadBumpPtrAllocator.h"
+#include <map>
+
+namespace llvm {
+
+class DWARFDie;
+
+namespace dwarflinker_parallel {
+
+using TranslatorFuncTy = std::function<StringRef(StringRef)>;
+using MessageHandlerTy = std::function<void(
+    const Twine &Warning, StringRef Context, const DWARFDie *DIE)>;
+
+/// linking options
+struct DWARFLinkerOptions {
+  /// DWARF version for the output.
+  uint16_t TargetDWARFVersion = 0;
+
+  /// Generate processing log to the standard output.
+  bool Verbose = false;
+
+  /// Print statistics.
+  bool Statistics = false;
+
+  /// Verify the input DWARF.
+  bool VerifyInputDWARF = false;
+
+  /// Do not emit output.
+  bool NoOutput = false;
+
+  /// Do not unique types according to ODR
+  bool NoODR = false;
+
+  /// Update index tables.
+  bool UpdateIndexTablesOnly = false;
+
+  /// Whether we want a static variable to force us to keep its enclosing
+  /// function.
+  bool KeepFunctionForStatic = false;
+
+  /// Allow to generate valid, but non deterministic output.
+  bool AllowNonDeterministicOutput = false;
+
+  /// Number of threads.
+  unsigned Threads = 1;
+
+  /// The accelerator table kinds
+  SmallVector<DWARFLinker::AccelTableKind, 1> AccelTables;
+
+  /// Prepend path for the clang modules.
+  std::string PrependPath;
+
+  /// input verification handler(it might be called asynchronously).
+  DWARFLinker::InputVerificationHandlerTy InputVerificationHandler = nullptr;
+
+  /// A list of all .swiftinterface files referenced by the debug
+  /// info, mapping Module name to path on disk. The entries need to
+  /// be uniqued and sorted and there are only few entries expected
+  /// per compile unit, which is why this is a std::map.
+  /// this is dsymutil specific fag.
+  ///
+  /// (it might be called asynchronously).
+  DWARFLinker::SwiftInterfacesMapTy *ParseableSwiftInterfaces = nullptr;
+
+  /// A list of remappings to apply to file paths.
+  ///
+  /// (it might be called asynchronously).
+  DWARFLinker::ObjectPrefixMapTy *ObjectPrefixMap = nullptr;
+};
+
+class DWARFLinkerImpl;
+
+/// This class keeps data and services common for the whole linking process.
+class LinkingGlobalData {
+  friend DWARFLinkerImpl;
+
+public:
+  /// Returns global per-thread allocator.
+  parallel::PerThreadBumpPtrAllocator &getAllocator() { return Allocator; }
+
+  /// Returns global string pool.
+  StringPool &getStringPool() { return Strings; }
+
+  /// Set translation function.
+  void setTranslator(TranslatorFuncTy Translator) {
+    this->Translator = Translator;
+  }
+
+  /// Translate specified string.
+  StringRef translateString(StringRef String) {
+    if (Translator)
+      return Translator(String);
+
+    return String;
+  }
+
+  /// Returns linking options.
+  const DWARFLinkerOptions &getOptions() const { return Options; }
+
+  /// Set warning handler.
+  void setWarningHandler(MessageHandlerTy Handler) { WarningHandler = Handler; }
+
+  /// Set error handler.
+  void setErrorHandler(MessageHandlerTy Handler) { ErrorHandler = Handler; }
+
+  /// Report warning.
+  void warn(const Twine &Warning, StringRef Context,
+            const DWARFDie *DIE = nullptr) {
+    if (WarningHandler)
+      (WarningHandler)(Warning, Context, DIE);
+  }
+
+  /// Report warning.
+  void warn(Error Warning, StringRef Context, const DWARFDie *DIE = nullptr) {
+    handleAllErrors(std::move(Warning), [&](ErrorInfoBase &Info) {
+      warn(Info.message(), Context, DIE);
+    });
+  }
+
+  /// Report error.
+  void error(const Twine &Err, StringRef Context,
+             const DWARFDie *DIE = nullptr) {
+    if (ErrorHandler)
+      (ErrorHandler)(Err, Context, DIE);
+  }
+
+  /// Report error.
+  void error(Error Err, StringRef Context, const DWARFDie *DIE = nullptr) {
+    handleAllErrors(std::move(Err), [&](ErrorInfoBase &Info) {
+      error(Info.message(), Context, DIE);
+    });
+  }
+
+protected:
+  parallel::PerThreadBumpPtrAllocator Allocator;
+  StringPool Strings;
+  TranslatorFuncTy Translator;
+  DWARFLinkerOptions Options;
+  MessageHandlerTy WarningHandler;
+  MessageHandlerTy ErrorHandler;
+};
+
+} // end of namespace dwarflinker_parallel
+} // end namespace llvm
+
+#endif // LLVM_LIB_DWARFLINKERPARALLEL_DWARFLINKERGLOBALDATA_H

llvm/lib/DWARFLinkerParallel/DWARFLinkerImpl.h

 //===- DWARFLinkerImpl.h ----------------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIB_DWARFLINKERPARALLEL_DWARFLINKERIMPL_H
 #define LLVM_LIB_DWARFLINKERPARALLEL_DWARFLINKERIMPL_H
 
 #include "DWARFEmitterImpl.h"
 #include "DWARFLinkerCompileUnit.h"
+#include "StringEntryToDwarfStringPoolEntryMap.h"
 #include "llvm/ADT/AddressRanges.h"
 #include "llvm/CodeGen/AccelTable.h"
 #include "llvm/DWARFLinkerParallel/DWARFLinker.h"
 #include "llvm/DWARFLinkerParallel/StringPool.h"
-#include "llvm/DWARFLinkerParallel/StringTable.h"
 
 namespace llvm {
 namespace dwarflinker_parallel {
 
-using Offset2UnitMapTy = DenseMap<uint64_t, CompileUnit *>;
-
-struct RangeAttrPatch;
-struct LocAttrPatch;
-
+/// This class links debug info.
 class DWARFLinkerImpl : public DWARFLinker {
 public:
   DWARFLinkerImpl(MessageHandlerTy ErrorHandler,
                   MessageHandlerTy WarningHandler,
                   TranslatorFuncTy StringsTranslator)
-      : UniqueUnitID(0), ErrorHandler(ErrorHandler),
-        WarningHandler(WarningHandler),
-        OutputStrings(Strings, StringsTranslator) {}
+      : UniqueUnitID(0), DebugStrStrings(GlobalData),
+        DebugLineStrStrings(GlobalData) {
+    GlobalData.setTranslator(StringsTranslator);
+    GlobalData.setErrorHandler(ErrorHandler);
+    GlobalData.setWarningHandler(WarningHandler);
+  }
 
+  /// Create debug info emitter.
   Error createEmitter(const Triple &TheTriple, OutputFileType FileType,
                       raw_pwrite_stream &OutFile) override;
 
   ExtraDwarfEmitter *getEmitter() override;
 
   /// Add object file to be linked. Pre-load compile unit die. Call
   /// \p OnCUDieLoaded for each compile unit die. If specified \p File
   /// has reference to the Clang module then such module would be
   /// pre-loaded by \p Loader for !Update case.
   ///
   /// \pre NoODR, Update options should be set before call to addObjectFile.
   void addObjectFile(
       DWARFFile &File, ObjFileLoaderTy Loader = nullptr,
-      CompileUnitHandlerTy OnCUDieLoaded = [](const DWARFUnit &) {}) override {}
+
+      CompileUnitHandlerTy OnCUDieLoaded = [](const DWARFUnit &) {}) override;
 
   /// Link debug info for added files.
-  Error link() override {
-    reportWarning("LLVM parallel dwarflinker is not implemented yet.", "");
-    return Error::success();
-  }
+  Error link() override;
 
   /// \defgroup Methods setting various linking options:
   ///
   /// @{
   ///
 
   /// Allows to generate log of linking process to the standard output.
-  void setVerbosity(bool Verbose) override { Options.Verbose = Verbose; }
+  void setVerbosity(bool Verbose) override {
+    GlobalData.Options.Verbose = Verbose;
+  }
 
   /// Print statistics to standard output.
   void setStatistics(bool Statistics) override {
-    Options.Statistics = Statistics;
+    GlobalData.Options.Statistics = Statistics;
   }
 
   /// Verify the input DWARF.
   void setVerifyInputDWARF(bool Verify) override {
-    Options.VerifyInputDWARF = Verify;
+    GlobalData.Options.VerifyInputDWARF = Verify;
   }
 
   /// Do not unique types according to ODR.
-  void setNoODR(bool NoODR) override { Options.NoODR = NoODR; }
+  void setNoODR(bool) override {
+    // FIXME: set option when ODR mode will be supported.
+    // getOptions().NoODR = NoODR;
+    GlobalData.Options.NoODR = true;
+  }
 
   /// Update index tables only(do not modify rest of DWARF).
   void setUpdateIndexTablesOnly(bool UpdateIndexTablesOnly) override {
-    Options.UpdateIndexTablesOnly = UpdateIndexTablesOnly;
+    GlobalData.Options.UpdateIndexTablesOnly = UpdateIndexTablesOnly;
   }
 
   /// Allow generating valid, but non-deterministic output.
   void
   setAllowNonDeterministicOutput(bool AllowNonDeterministicOutput) override {
-    Options.AllowNonDeterministicOutput = AllowNonDeterministicOutput;
+    GlobalData.Options.AllowNonDeterministicOutput =
+        AllowNonDeterministicOutput;
   }
 
   /// Set to keep the enclosing function for a static variable.
   void setKeepFunctionForStatic(bool KeepFunctionForStatic) override {
-    Options.KeepFunctionForStatic = KeepFunctionForStatic;
+    GlobalData.Options.KeepFunctionForStatic = KeepFunctionForStatic;
   }
 
   /// Use specified number of threads for parallel files linking.
   void setNumThreads(unsigned NumThreads) override {
-    Options.Threads = NumThreads;
+    GlobalData.Options.Threads = NumThreads;
   }
 
   /// Add kind of accelerator tables to be generated.
   void addAccelTableKind(AccelTableKind Kind) override {
-    assert(!llvm::is_contained(Options.AccelTables, Kind));
-    Options.AccelTables.emplace_back(Kind);
+    assert(!llvm::is_contained(GlobalData.getOptions().AccelTables, Kind));
+    GlobalData.Options.AccelTables.emplace_back(Kind);
   }
 
   /// Set prepend path for clang modules.
   void setPrependPath(const std::string &Ppath) override {
-    Options.PrependPath = Ppath;
+    GlobalData.Options.PrependPath = Ppath;
   }
 
   /// Set estimated objects files amount, for preliminary data allocation.
   void setEstimatedObjfilesAmount(unsigned ObjFilesNum) override {
     ObjectContexts.reserve(ObjFilesNum);
   }
 
   /// Set verification handler which would be used to report verification
   /// errors.
   void
   setInputVerificationHandler(InputVerificationHandlerTy Handler) override {
-    Options.InputVerificationHandler = Handler;
+    GlobalData.Options.InputVerificationHandler = Handler;
   }
 
   /// Set map for Swift interfaces.
   void setSwiftInterfacesMap(SwiftInterfacesMapTy *Map) override {
-    Options.ParseableSwiftInterfaces = Map;
+    GlobalData.Options.ParseableSwiftInterfaces = Map;
   }
 
   /// Set prefix map for objects.
   void setObjectPrefixMap(ObjectPrefixMapTy *Map) override {
-    Options.ObjectPrefixMap = Map;
+    GlobalData.Options.ObjectPrefixMap = Map;
   }
 
   /// Set target DWARF version.
   Error setTargetDWARFVersion(uint16_t TargetDWARFVersion) override {
     if ((TargetDWARFVersion < 1) || (TargetDWARFVersion > 5))
       return createStringError(std::errc::invalid_argument,
                                "unsupported DWARF version: %d",
                                TargetDWARFVersion);
 
-    Options.TargetDWARFVersion = TargetDWARFVersion;
+    GlobalData.Options.TargetDWARFVersion = TargetDWARFVersion;
     return Error::success();
   }
   /// @}
 
 protected:
-  /// Reports Warning.
-  void reportWarning(const Twine &Warning, const DWARFFile &File,
-                     const DWARFDie *DIE = nullptr) const {
-    if (WarningHandler != nullptr)
-      WarningHandler(Warning, File.FileName, DIE);
-  }
+  /// Verify input DWARF file.
+  void verifyInput(const DWARFFile &File);
 
-  /// Reports Warning.
-  void reportWarning(const Twine &Warning, StringRef FileName,
-                     const DWARFDie *DIE = nullptr) const {
-    if (WarningHandler != nullptr)
-      WarningHandler(Warning, FileName, DIE);
-  }
+  /// Validate specified options.
+  Error validateAndUpdateOptions();
 
-  /// Reports Error.
-  void reportError(const Twine &Warning, StringRef FileName,
-                   const DWARFDie *DIE = nullptr) const {
-    if (ErrorHandler != nullptr)
-      ErrorHandler(Warning, FileName, DIE);
-  }
+  /// Take already linked compile units and glue them into single file.
+  void glueCompileUnitsAndWriteToTheOutput();
 
-  /// Returns next available unique Compile Unit ID.
-  unsigned getNextUniqueUnitID() { return UniqueUnitID.fetch_add(1); }
+  /// Increment counter for specified \p File.
+  void addBinHolderNameRef(DWARFFile &File);
+
+  /// Decrement counter for specified \p File and unload file if counter
+  /// becomes zero.
+  void unloadObjectFile(DWARFFile &File);
+
+  /// Hold the input and output of the debug info size in bytes.
+  struct DebugInfoSize {
+    uint64_t Input;
+    uint64_t Output;
+  };
 
+  friend class DependencyTracker;
   /// Keeps track of data associated with one object during linking.
   /// i.e. source file descriptor, compilation units, output data
   /// for compilation units common tables.
   struct LinkContext : public OutputSections {
     using UnitListTy = SmallVector<std::unique_ptr<CompileUnit>>;
 
     /// Keep information for referenced clang module: already loaded DWARF info
     /// of the clang module and a CompileUnit of the module.
     struct RefModuleUnit {
       RefModuleUnit(DWARFFile &File, std::unique_ptr<CompileUnit> Unit)
           : File(File), Unit(std::move(Unit)) {}
       RefModuleUnit(RefModuleUnit &&Other)
           : File(Other.File), Unit(std::move(Other.Unit)) {}
       RefModuleUnit(const RefModuleUnit &) = delete;
 
       DWARFFile &File;
       std::unique_ptr<CompileUnit> Unit;
     };
     using ModuleUnitListTy = SmallVector<RefModuleUnit>;
 
+    /// Global linking data.
+    LinkingGlobalData &GlobalData;
+
     /// Object file descriptor.
-    DWARFFile &File;
+    DWARFFile &InputDWARFFile;
 
     /// Set of Compilation Units(may be accessed asynchroniously for reading).
     UnitListTy CompileUnits;
 
     /// Set of Compile Units for modules.
     ModuleUnitListTy ModulesCompileUnits;
 
     /// Size of Debug info before optimizing.
     uint64_t OriginalDebugInfoSize = 0;
 
-    /// Output sections, common for all compilation units.
-    OutTablesFileTy OutDebugInfoBytes;
+    /// Flag indicating that all inter-connected units are loaded
+    /// and the dwarf linking process for these units is started.
+    bool InterCUProcessingStarted = false;
+
+    StringMap<uint64_t> &ClangModules;
+
+    std::optional<Triple> TargetTriple;
+
+    /// Flag indicating that new inter-connected compilation units were
+    /// discovered. It is used for restarting units processing
+    /// if new inter-connected units were found.
+    std::atomic<bool> HasNewInterconnectedCUs = {false};
+
+    /// Counter for compile units ID.
+    std::atomic<size_t> &UniqueUnitID;
+
+    LinkContext(LinkingGlobalData &GlobalData, DWARFFile &File,
+                StringMap<uint64_t> &ClangModules,
+                std::atomic<size_t> &UniqueUnitID,
+                std::optional<Triple> TargetTriple)
+        : GlobalData(GlobalData), InputDWARFFile(File),
+          ClangModules(ClangModules), TargetTriple(TargetTriple),
+          UniqueUnitID(UniqueUnitID) {
+      setGlobalData(&GlobalData);
 
-    /// Endianness for the final file.
-    support::endianness Endianess = support::endianness::little;
-
-    LinkContext(DWARFFile &File) : File(File) {
       if (File.Dwarf) {
         if (!File.Dwarf->compile_units().empty())
           CompileUnits.reserve(File.Dwarf->getNumCompileUnits());
-
-        Endianess = File.Dwarf->isLittleEndian() ? support::endianness::little
-                                                 : support::endianness::big;
       }
     }
 
+    /// Check whether specified \p CUDie is a Clang module reference.
+    /// if \p Quiet is false then display error messages.
+    /// \return first == true if CUDie is a Clang module reference.
+    ///         second == true if module is already loaded.
+    std::pair<bool, bool> isClangModuleRef(const DWARFDie &CUDie,
+                                           std::string &PCMFile,
+                                           unsigned Indent, bool Quiet);
+
+    /// If this compile unit is really a skeleton CU that points to a
+    /// clang module, register it in ClangModules and return true.
+    ///
+    /// A skeleton CU is a CU without children, a DW_AT_gnu_dwo_name
+    /// pointing to the module, and a DW_AT_gnu_dwo_id with the module
+    /// hash.
+    bool registerModuleReference(const DWARFDie &CUDie, ObjFileLoaderTy Loader,
+                                 CompileUnitHandlerTy OnCUDieLoaded,
+                                 unsigned Indent = 0);
+
+    /// Recursively add the debug info in this clang module .pcm
+    /// file (and all the modules imported by it in a bottom-up fashion)
+    /// to ModuleUnits.
+    Error loadClangModule(ObjFileLoaderTy Loader, const DWARFDie &CUDie,
+                          const std::string &PCMFile,
+                          CompileUnitHandlerTy OnCUDieLoaded,
+                          unsigned Indent = 0);
+
     /// Add Compile Unit corresponding to the module.
     void addModulesCompileUnit(RefModuleUnit &&Unit) {
       ModulesCompileUnits.emplace_back(std::move(Unit));
     }
 
-    /// Return Endiannes of the source DWARF information.
-    support::endianness getEndianness() { return Endianess; }
-
-    /// \returns pointer to compilation unit which corresponds \p Offset.
-    CompileUnit *getUnitForOffset(CompileUnit &CU, uint64_t Offset) const;
-  };
+    /// Computes the total size of the debug info.
+    uint64_t getInputDebugInfoSize() const {
+      uint64_t Size = 0;
 
-  /// linking options
-  struct DWARFLinkerOptions {
-    /// DWARF version for the output.
-    uint16_t TargetDWARFVersion = 0;
+      if (InputDWARFFile.Dwarf == nullptr)
+        return Size;
 
-    /// Generate processing log to the standard output.
-    bool Verbose = false;
+      for (auto &Unit : InputDWARFFile.Dwarf->compile_units())
+        Size += Unit->getLength();
 
-    /// Print statistics.
-    bool Statistics = false;
+      return Size;
+    }
 
-    /// Verify the input DWARF.
-    bool VerifyInputDWARF = false;
+    /// Link compile units for this context.
+    Error link();
 
-    /// Do not unique types according to ODR
-    bool NoODR = false;
+    /// Link specified compile unit until specified stage.
+    void linkSingleCompileUnit(
+        CompileUnit &CU,
+        enum CompileUnit::Stage DoUntilStage = CompileUnit::Stage::Cleaned);
 
-    /// Update index tables.
-    bool UpdateIndexTablesOnly = false;
+    /// Emit invariant sections.
+    Error emitInvariantSections();
 
-    /// Whether we want a static variable to force us to keep its enclosing
-    /// function.
-    bool KeepFunctionForStatic = false;
+    /// Clone and emit .debug_frame.
+    Error cloneAndEmitDebugFrame();
 
-    /// Allow to generate valid, but non deterministic output.
-    bool AllowNonDeterministicOutput = false;
+    /// Emit FDE record.
+    void emitFDE(uint32_t CIEOffset, uint32_t AddrSize, uint64_t Address,
+                 StringRef FDEBytes, SectionDescriptor &Section);
 
-    /// Number of threads.
-    unsigned Threads = 1;
+    /// Clone and emit paper trails.
+    Error cloneAndEmitPaperTrails();
 
-    /// The accelerator table kinds
-    SmallVector<AccelTableKind, 1> AccelTables;
+    std::function<CompileUnit *(uint64_t)> getUnitForOffset =
+        [&](uint64_t Offset) -> CompileUnit * {
+      auto CU = llvm::upper_bound(
+          CompileUnits, Offset,
+          [](uint64_t LHS, const std::unique_ptr<CompileUnit> &RHS) {
+            return LHS < RHS->getOrigUnit().getNextUnitOffset();
+          });
 
-    /// Prepend path for the clang modules.
-    std::string PrependPath;
+      return CU != CompileUnits.end() ? CU->get() : nullptr;
+    };
+  };
 
-    /// input verification handler(it might be called asynchronously).
-    InputVerificationHandlerTy InputVerificationHandler = nullptr;
+  /// Enumerate all compile units and assign offsets to their sections and
+  /// strings.
+  void assignOffsets();
+
+  /// Enumerate all compile units and assign offsets to their sections.
+  void assignOffsetsToSections();
+
+  /// Enumerate all compile units and assign offsets to their strings.
+  void assignOffsetsToStrings();
+
+  /// Enumerates specified string patches, assigns offset and index.
+  template <typename PatchTy>
+  void assignOffsetsToStringsImpl(
+      ArrayList<PatchTy> &Section, size_t &IndexAccumulator,
+      uint64_t &OffsetAccumulator,
+      StringEntryToDwarfStringPoolEntryMap &StringsForEmission);
+
+  /// Print statistic for processed Debug Info.
+  void printStatistic();
+
+  /// Enumerates sections for modules, invariant for object files, compile
+  /// units.
+  void forEachSectionsSet(
+      function_ref<void(OutputSections &SectionsSet)> SectionsSetHandler);
 
-    /// A list of all .swiftinterface files referenced by the debug
-    /// info, mapping Module name to path on disk. The entries need to
-    /// be uniqued and sorted and there are only few entries expected
-    /// per compile unit, which is why this is a std::map.
-    /// this is dsymutil specific fag.
-    ///
-    /// (it might be called asynchronously).
-    SwiftInterfacesMapTy *ParseableSwiftInterfaces = nullptr;
+  /// Enumerates all patches and update them with the correct values.
+  void patchOffsetsAndSizes();
 
-    /// A list of remappings to apply to file paths.
-    ///
-    /// (it might be called asynchronously).
-    ObjectPrefixMapTy *ObjectPrefixMap = nullptr;
-  } Options;
+  /// Enumerate all compile units and put their data into the output stream.
+  void writeDWARFToTheOutput();
 
   /// \defgroup Data members accessed asinchroniously.
   ///
   /// @{
 
   /// Unique ID for compile unit.
-  std::atomic<unsigned> UniqueUnitID;
-
-  /// Strings pool. Keeps all strings.
-  StringPool Strings;
+  std::atomic<size_t> UniqueUnitID;
 
-  /// error handler(it might be called asynchronously).
-  MessageHandlerTy ErrorHandler = nullptr;
-
-  /// warning handler(it might be called asynchronously).
-  MessageHandlerTy WarningHandler = nullptr;
+  /// BinaryHolderRefCounter counts whether references to the binary
+  /// files exist.
+  DenseMap<StringRef, uint32_t> BinaryHolderRefCounter;
+  std::mutex BinaryHolderRefMutex;
+
+  /// Mapping the PCM filename to the DwoId.
+  StringMap<uint64_t> ClangModules;
+  std::mutex ClangModulesMutex;
   /// @}
 
   /// \defgroup Data members accessed sequentially.
   ///
   /// @{
+  /// DwarfStringPoolEntries for .debug_str section.
+  StringEntryToDwarfStringPoolEntryMap DebugStrStrings;
 
-  /// Set of strings which should be emitted.
-  StringTable OutputStrings;
+  /// DwarfStringPoolEntries for .debug_line_str section.
+  StringEntryToDwarfStringPoolEntryMap DebugLineStrStrings;
 
   /// Keeps all linking contexts.
   SmallVector<std::unique_ptr<LinkContext>> ObjectContexts;
 
   /// The emitter of final dwarf file.
   std::unique_ptr<DwarfEmitterImpl> TheDwarfEmitter;
+
+  /// Overall compile units number.
+  uint64_t OverallNumberOfCU = 0;
+
+  /// Data global for the whole linking process.
+  LinkingGlobalData GlobalData;
   /// @}
 };
 
 } // end namespace dwarflinker_parallel
 } // end namespace llvm
 
 #endif // LLVM_LIB_DWARFLINKERPARALLEL_DWARFLINKERIMPL_H

llvm/lib/DWARFLinkerParallel/DWARFLinkerImpl.cpp

 //=== DWARFLinkerImpl.cpp -------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "DWARFLinkerImpl.h"
+#include "DIEGenerator.h"
+#include "DependencyTracker.h"
+#include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/Parallel.h"
+#include "llvm/Support/ThreadPool.h"
 
 namespace llvm {
 namespace dwarflinker_parallel {
 
-/// Similar to DWARFUnitSection::getUnitForOffset(), but returning our
-/// CompileUnit object instead.
-CompileUnit *
-DWARFLinkerImpl::LinkContext::getUnitForOffset(CompileUnit &CurrentCU,
-                                               uint64_t Offset) const {
-  if (CurrentCU.isClangModule())
-    return &CurrentCU;
-
-  auto CU = llvm::upper_bound(
-      CompileUnits, Offset,
-      [](uint64_t LHS, const std::unique_ptr<CompileUnit> &RHS) {
-        return LHS < RHS->getOrigUnit().getNextUnitOffset();
-      });
-
-  return CU != CompileUnits.end() ? CU->get() : nullptr;
-}
-
 Error DWARFLinkerImpl::createEmitter(const Triple &TheTriple,
                                      OutputFileType FileType,
                                      raw_pwrite_stream &OutFile) {
 
-  TheDwarfEmitter = std::make_unique<DwarfEmitterImpl>(
-      FileType, OutFile, OutputStrings.getTranslator(), WarningHandler);
+  TheDwarfEmitter = std::make_unique<DwarfEmitterImpl>(FileType, OutFile);
 
   return TheDwarfEmitter->init(TheTriple, "__DWARF");
 }
 
 ExtraDwarfEmitter *DWARFLinkerImpl::getEmitter() {
   return TheDwarfEmitter.get();
 }
 
+void DWARFLinkerImpl::addObjectFile(DWARFFile &File, ObjFileLoaderTy Loader,
+                                    CompileUnitHandlerTy OnCUDieLoaded) {
+  ObjectContexts.emplace_back(std::make_unique<LinkContext>(
+      GlobalData, File, ClangModules, UniqueUnitID,
+      (TheDwarfEmitter.get() == nullptr ? std::optional<Triple>(std::nullopt)
+                                        : TheDwarfEmitter->getTargetTriple())));
+
+  // Count references to source files.
+  addBinHolderNameRef(ObjectContexts.back()->InputDWARFFile);
+
+  if (ObjectContexts.back()->InputDWARFFile.Dwarf) {
+    for (const std::unique_ptr<DWARFUnit> &CU :
+         ObjectContexts.back()->InputDWARFFile.Dwarf->compile_units()) {
+      DWARFDie CUDie = CU->getUnitDIE();
+      OverallNumberOfCU++;
+
+      if (!CUDie)
+        continue;
+
+      OnCUDieLoaded(*CU);
+
+      // Register mofule reference.
+      if (!GlobalData.getOptions().UpdateIndexTablesOnly)
+        ObjectContexts.back()->registerModuleReference(CUDie, Loader,
+                                                       OnCUDieLoaded);
+    }
+  }
+}
+
+Error DWARFLinkerImpl::link() {
+  // reset compile unit unique ID counter.
+  UniqueUnitID = 0;
+
+  if (Error Err = validateAndUpdateOptions())
+    return Err;
+
+  if (GlobalData.getOptions().Verbose) {
+    for (std::unique_ptr<LinkContext> &Context : ObjectContexts) {
+      outs() << "OBJECT: " << Context->InputDWARFFile.FileName << "\n";
+
+      if (Context->InputDWARFFile.Dwarf) {
+        for (const std::unique_ptr<DWARFUnit> &OrigCU :
+             Context->InputDWARFFile.Dwarf->compile_units()) {
+          outs() << "Input compilation unit:";
+          DIDumpOptions DumpOpts;
+          DumpOpts.ChildRecurseDepth = 0;
+          DumpOpts.Verbose = GlobalData.getOptions().Verbose;
+          OrigCU->getUnitDIE().dump(outs(), 0, DumpOpts);
+        }
+      }
+    }
+  }
+
+  // Verify input DWARF if requested.
+  if (GlobalData.getOptions().VerifyInputDWARF) {
+    for (std::unique_ptr<LinkContext> &Context : ObjectContexts) {
+      if (Context->InputDWARFFile.Dwarf) {
+        if (GlobalData.getOptions().VerifyInputDWARF)
+          verifyInput(Context->InputDWARFFile);
+      }
+    }
+  }
+
+  // Set parallel options.
+  if (GlobalData.getOptions().Threads == 0)
+    parallel::strategy = optimal_concurrency(OverallNumberOfCU);
+  else
+    parallel::strategy = hardware_concurrency(GlobalData.getOptions().Threads);
+
+  // Link object files.
+  if (GlobalData.getOptions().Threads == 1) {
+    for (std::unique_ptr<LinkContext> &Context : ObjectContexts) {
+      // Link object file.
+      if (Error Err = Context->link())
+        GlobalData.error(std::move(Err), Context->InputDWARFFile.FileName);
+
+      unloadObjectFile(Context->InputDWARFFile);
+    }
+  } else {
+    ThreadPool Pool(parallel::strategy);
+    for (std::unique_ptr<LinkContext> &Context : ObjectContexts)
+      Pool.async([&]() {
+        // Link object file.
+        if (Error Err = Context->link())
+          GlobalData.error(std::move(Err), Context->InputDWARFFile.FileName);
+
+        unloadObjectFile(Context->InputDWARFFile);
+      });
+
+    Pool.wait();
+  }
+
+  // At this stage each compile units are cloned to their own set of debug
+  // sections. Now, update patches, assign offsets and assemble final file
+  // glueing debug tables from each compile unit.
+  glueCompileUnitsAndWriteToTheOutput();
+
+  return Error::success();
+}
+
+void DWARFLinkerImpl::verifyInput(const DWARFFile &File) {
+  assert(File.Dwarf);
+
+  raw_ostream &os = GlobalData.getOptions().Verbose ? errs() : nulls();
+  DIDumpOptions DumpOpts;
+  if (!File.Dwarf->verify(os, DumpOpts.noImplicitRecursion())) {
+    if (GlobalData.getOptions().InputVerificationHandler)
+      GlobalData.getOptions().InputVerificationHandler(File);
+  }
+}
+
+Error DWARFLinkerImpl::validateAndUpdateOptions() {
+  if (GlobalData.getOptions().TargetDWARFVersion == 0)
+    return createStringError(std::errc::invalid_argument,
+                             "target DWARF version is not set");
+
+  GlobalData.Options.NoOutput = TheDwarfEmitter.get() == nullptr;
+
+  if (GlobalData.getOptions().Verbose && GlobalData.getOptions().Threads != 1) {
+    GlobalData.Options.Threads = 1;
+    GlobalData.warn(
+        "set number of threads to 1 to make --verbose to work properly.", "");
+  }
+
+  return Error::success();
+}
+
+static bool isArchive(StringRef Name) { return Name.endswith(")"); }
+
+static StringRef getBinaryHolderName(StringRef Name) {
+  if (isArchive(Name))
+    return Name.substr(0, Name.rfind('('));
+
+  return Name;
+}
+
+void DWARFLinkerImpl::addBinHolderNameRef(DWARFFile &File) {
+  BinaryHolderRefCounter[getBinaryHolderName(File.FileName)]++;
+}
+
+void DWARFLinkerImpl::unloadObjectFile(DWARFFile &File) {
+  std::unique_lock<std::mutex> Guard(BinaryHolderRefMutex);
+
+  assert(BinaryHolderRefCounter[getBinaryHolderName(File.FileName)] != 0);
+
+  // we could not simply unload object file here.
+  // Object file might be a member of an archive.
+  // Unloading object file in such case would also
+  // unload containing archive. Thus we count references
+  // to the archive and unload it when there are no
+  // more unprocessed archive members.
+  BinaryHolderRefCounter[getBinaryHolderName(File.FileName)]--;
+
+  if (BinaryHolderRefCounter[getBinaryHolderName(File.FileName)] == 0)
+    File.unload();
+}
+
+/// Resolve the relative path to a build artifact referenced by DWARF by
+/// applying DW_AT_comp_dir.
+static void resolveRelativeObjectPath(SmallVectorImpl<char> &Buf, DWARFDie CU) {
+  sys::path::append(Buf, dwarf::toString(CU.find(dwarf::DW_AT_comp_dir), ""));
+}
+
+static uint64_t getDwoId(const DWARFDie &CUDie) {
+  auto DwoId = dwarf::toUnsigned(
+      CUDie.find({dwarf::DW_AT_dwo_id, dwarf::DW_AT_GNU_dwo_id}));
+  if (DwoId)
+    return *DwoId;
+  return 0;
+}
+
+static std::string
+remapPath(StringRef Path,
+          const DWARFLinker::ObjectPrefixMapTy &ObjectPrefixMap) {
+  if (ObjectPrefixMap.empty())
+    return Path.str();
+
+  SmallString<256> p = Path;
+  for (const auto &Entry : ObjectPrefixMap)
+    if (llvm::sys::path::replace_path_prefix(p, Entry.first, Entry.second))
+      break;
+  return p.str().str();
+}
+
+static std::string getPCMFile(const DWARFDie &CUDie,
+                              DWARFLinker::ObjectPrefixMapTy *ObjectPrefixMap) {
+  std::string PCMFile = dwarf::toString(
+      CUDie.find({dwarf::DW_AT_dwo_name, dwarf::DW_AT_GNU_dwo_name}), "");
+
+  if (PCMFile.empty())
+    return PCMFile;
+
+  if (ObjectPrefixMap)
+    PCMFile = remapPath(PCMFile, *ObjectPrefixMap);
+
+  return PCMFile;
+}
+
+std::pair<bool, bool> DWARFLinkerImpl::LinkContext::isClangModuleRef(
+    const DWARFDie &CUDie, std::string &PCMFile, unsigned Indent, bool Quiet) {
+  if (PCMFile.empty())
+    return std::make_pair(false, false);
+
+  // Clang module DWARF skeleton CUs abuse this for the path to the module.
+  uint64_t DwoId = getDwoId(CUDie);
+
+  std::string Name = dwarf::toString(CUDie.find(dwarf::DW_AT_name), "");
+  if (Name.empty()) {
+    if (!Quiet)
+      GlobalData.warn("anonymous module skeleton CU for " + PCMFile + ".",
+                      InputDWARFFile.FileName);
+    return std::make_pair(true, true);
+  }
+
+  if (!Quiet && GlobalData.getOptions().Verbose) {
+    outs().indent(Indent);
+    outs() << "Found clang module reference " << PCMFile;
+  }
+
+  auto Cached = ClangModules.find(PCMFile);
+  if (Cached != ClangModules.end()) {
+    // FIXME: Until PR27449 (https://llvm.org/bugs/show_bug.cgi?id=27449) is
+    // fixed in clang, only warn about DWO_id mismatches in verbose mode.
+    // ASTFileSignatures will change randomly when a module is rebuilt.
+    if (!Quiet && GlobalData.getOptions().Verbose && (Cached->second != DwoId))
+      GlobalData.warn(
+          Twine("hash mismatch: this object file was built against a "
+                "different version of the module ") +
+              PCMFile + ".",
+          InputDWARFFile.FileName);
+    if (!Quiet && GlobalData.getOptions().Verbose)
+      outs() << " [cached].\n";
+    return std::make_pair(true, true);
+  }
+
+  return std::make_pair(true, false);
+}
+
+/// If this compile unit is really a skeleton CU that points to a
+/// clang module, register it in ClangModules and return true.
+///
+/// A skeleton CU is a CU without children, a DW_AT_gnu_dwo_name
+/// pointing to the module, and a DW_AT_gnu_dwo_id with the module
+/// hash.
+bool DWARFLinkerImpl::LinkContext::registerModuleReference(
+    const DWARFDie &CUDie, ObjFileLoaderTy Loader,
+    CompileUnitHandlerTy OnCUDieLoaded, unsigned Indent) {
+  std::string PCMFile =
+      getPCMFile(CUDie, GlobalData.getOptions().ObjectPrefixMap);
+  std::pair<bool, bool> IsClangModuleRef =
+      isClangModuleRef(CUDie, PCMFile, Indent, false);
+
+  if (!IsClangModuleRef.first)
+    return false;
+
+  if (IsClangModuleRef.second)
+    return true;
+
+  if (GlobalData.getOptions().Verbose)
+    outs() << " ...\n";
+
+  // Cyclic dependencies are disallowed by Clang, but we still
+  // shouldn't run into an infinite loop, so mark it as processed now.
+  ClangModules.insert({PCMFile, getDwoId(CUDie)});
+
+  if (Error E =
+          loadClangModule(Loader, CUDie, PCMFile, OnCUDieLoaded, Indent + 2)) {
+    consumeError(std::move(E));
+    return false;
+  }
+  return true;
+}
+
+Error DWARFLinkerImpl::LinkContext::loadClangModule(
+    ObjFileLoaderTy Loader, const DWARFDie &CUDie, const std::string &PCMFile,
+    CompileUnitHandlerTy OnCUDieLoaded, unsigned Indent) {
+
+  uint64_t DwoId = getDwoId(CUDie);
+  std::string ModuleName = dwarf::toString(CUDie.find(dwarf::DW_AT_name), "");
+
+  /// Using a SmallString<0> because loadClangModule() is recursive.
+  SmallString<0> Path(GlobalData.getOptions().PrependPath);
+  if (sys::path::is_relative(PCMFile))
+    resolveRelativeObjectPath(Path, CUDie);
+  sys::path::append(Path, PCMFile);
+  // Don't use the cached binary holder because we have no thread-safety
+  // guarantee and the lifetime is limited.
+
+  if (Loader == nullptr) {
+    GlobalData.error("cann't load clang module: loader is not specified.",
+                     InputDWARFFile.FileName);
+    return Error::success();
+  }
+
+  auto ErrOrObj = Loader(InputDWARFFile.FileName, Path);
+  if (!ErrOrObj)
+    return Error::success();
+
+  std::unique_ptr<CompileUnit> Unit;
+  for (const auto &CU : ErrOrObj->Dwarf->compile_units()) {
+    OnCUDieLoaded(*CU);
+    // Recursively get all modules imported by this one.
+    auto ChildCUDie = CU->getUnitDIE();
+    if (!ChildCUDie)
+      continue;
+    if (!registerModuleReference(ChildCUDie, Loader, OnCUDieLoaded, Indent)) {
+      if (Unit) {
+        std::string Err =
+            (PCMFile +
+             ": Clang modules are expected to have exactly 1 compile unit.\n");
+        GlobalData.error(Err, InputDWARFFile.FileName);
+        return make_error<StringError>(Err, inconvertibleErrorCode());
+      }
+      // FIXME: Until PR27449 (https://llvm.org/bugs/show_bug.cgi?id=27449) is
+      // fixed in clang, only warn about DWO_id mismatches in verbose mode.
+      // ASTFileSignatures will change randomly when a module is rebuilt.
+      uint64_t PCMDwoId = getDwoId(ChildCUDie);
+      if (PCMDwoId != DwoId) {
+        if (GlobalData.getOptions().Verbose)
+          GlobalData.warn(
+              Twine("hash mismatch: this object file was built against a "
+                    "different version of the module ") +
+                  PCMFile + ".",
+              InputDWARFFile.FileName);
+        // Update the cache entry with the DwoId of the module loaded from disk.
+        ClangModules[PCMFile] = PCMDwoId;
+      }
+
+      // Empty modules units should not be cloned.
+      if (!ChildCUDie.hasChildren())
+        continue;
+
+      // Add this module.
+      Unit = std::make_unique<CompileUnit>(
+          GlobalData, *CU, UniqueUnitID.fetch_add(1), ModuleName, *ErrOrObj,
+          getUnitForOffset);
+    }
+  }
+
+  if (Unit) {
+    ModulesCompileUnits.emplace_back(RefModuleUnit{*ErrOrObj, std::move(Unit)});
+    // Preload line table, as it can't be loaded asynchronously.
+    ModulesCompileUnits.back().Unit->loadLineTable();
+  }
+
+  return Error::success();
+}
+
+Error DWARFLinkerImpl::LinkContext::link() {
+  InterCUProcessingStarted = false;
+  if (InputDWARFFile.Warnings.empty()) {
+    if (!InputDWARFFile.Dwarf)
+      return Error::success();
+
+    // Preload macro tables, as they can't be loaded asynchronously.
+    InputDWARFFile.Dwarf->getDebugMacinfo();
+    InputDWARFFile.Dwarf->getDebugMacro();
+
+    // Link modules compile units first.
+    parallelForEach(ModulesCompileUnits, [&](RefModuleUnit &RefModule) {
+      linkSingleCompileUnit(*RefModule.Unit);
+    });
+
+    // Check for live relocations. If there is no any live relocation then we
+    // can skip entire object file.
+    if (!GlobalData.getOptions().UpdateIndexTablesOnly &&
+        !InputDWARFFile.Addresses->hasValidRelocs()) {
+      if (GlobalData.getOptions().Verbose)
+        outs() << "No valid relocations found. Skipping.\n";
+      return Error::success();
+    }
+
+    OriginalDebugInfoSize = getInputDebugInfoSize();
+
+    // Create CompileUnit structures to keep information about source
+    // DWARFUnit`s, load line tables.
+    for (const auto &OrigCU : InputDWARFFile.Dwarf->compile_units()) {
+      // Load only unit DIE at this stage.
+      auto CUDie = OrigCU->getUnitDIE();
+      std::string PCMFile =
+          getPCMFile(CUDie, GlobalData.getOptions().ObjectPrefixMap);
+
+      // The !isClangModuleRef condition effectively skips over fully resolved
+      // skeleton units.
+      if (!CUDie || GlobalData.getOptions().UpdateIndexTablesOnly ||
+          !isClangModuleRef(CUDie, PCMFile, 0, true).first) {
+        CompileUnits.emplace_back(std::make_unique<CompileUnit>(
+            GlobalData, *OrigCU, UniqueUnitID.fetch_add(1), "", InputDWARFFile,
+            getUnitForOffset));
+
+        // Preload line table, as it can't be loaded asynchronously.
+        CompileUnits.back()->loadLineTable();
+      }
+    };
+
+    HasNewInterconnectedCUs = false;
+
+    // Link self-sufficient compile units and discover inter-connected compile
+    // units.
+    parallelForEach(CompileUnits, [&](std::unique_ptr<CompileUnit> &CU) {
+      linkSingleCompileUnit(*CU);
+    });
+
+    // Link all inter-connected units.
+    if (HasNewInterconnectedCUs) {
+      InterCUProcessingStarted = true;
+
+      do {
+        HasNewInterconnectedCUs = false;
+
+        // Load inter-connected units.
+        parallelForEach(CompileUnits, [&](std::unique_ptr<CompileUnit> &CU) {
+          if (CU->isInterconnectedCU()) {
+            CU->maybeResetToLoadedStage();
+            linkSingleCompileUnit(*CU, CompileUnit::Stage::Loaded);
+          }
+        });
+
+        // Do liveness analysis for inter-connected units.
+        parallelForEach(CompileUnits, [&](std::unique_ptr<CompileUnit> &CU) {
+          linkSingleCompileUnit(*CU, CompileUnit::Stage::LivenessAnalysisDone);
+        });
+      } while (HasNewInterconnectedCUs);
+
+      // Clone inter-connected units.
+      parallelForEach(CompileUnits, [&](std::unique_ptr<CompileUnit> &CU) {
+        linkSingleCompileUnit(*CU, CompileUnit::Stage::Cloned);
+      });
+
+      // Update patches for inter-connected units.
+      parallelForEach(CompileUnits, [&](std::unique_ptr<CompileUnit> &CU) {
+        linkSingleCompileUnit(*CU, CompileUnit::Stage::PatchesUpdated);
+      });
+
+      // Release data.
+      parallelForEach(CompileUnits, [&](std::unique_ptr<CompileUnit> &CU) {
+        linkSingleCompileUnit(*CU, CompileUnit::Stage::Cleaned);
+      });
+    }
+  }
+
+  if (!InputDWARFFile.Warnings.empty()) {
+    // Create compile unit with paper trail warnings.
+
+    Error ResultErr = Error::success();
+    // We use task group here as PerThreadBumpPtrAllocator should be called from
+    // the threads created by ThreadPoolExecutor.
+    parallel::TaskGroup TGroup;
+    TGroup.spawn([&]() {
+      if (Error Err = cloneAndEmitPaperTrails())
+        ResultErr = std::move(Err);
+    });
+    return ResultErr;
+  } else if (GlobalData.getOptions().UpdateIndexTablesOnly) {
+    // Emit Invariant sections.
+
+    if (Error Err = emitInvariantSections())
+      return Err;
+  } else if (!CompileUnits.empty()) {
+    // Emit .debug_frame section.
+
+    Error ResultErr = Error::success();
+    parallel::TaskGroup TGroup;
+    // We use task group here as PerThreadBumpPtrAllocator should be called from
+    // the threads created by ThreadPoolExecutor.
+    TGroup.spawn([&]() {
+      if (Error Err = cloneAndEmitDebugFrame())
+        ResultErr = std::move(Err);
+    });
+    return ResultErr;
+  }
+
+  return Error::success();
+}
+
+void DWARFLinkerImpl::LinkContext::linkSingleCompileUnit(
+    CompileUnit &CU, enum CompileUnit::Stage DoUntilStage) {
+  while (CU.getStage() < DoUntilStage) {
+    if (InterCUProcessingStarted != CU.isInterconnectedCU())
+      return;
+
+    switch (CU.getStage()) {
+    case CompileUnit::Stage::CreatedNotLoaded: {
+      // Load input compilation unit DIEs.
+      // Analyze properties of DIEs.
+      if (!CU.loadInputDIEs()) {
+        // We do not need to do liveness analysis for invalud compilation unit.
+        CU.setStage(CompileUnit::Stage::LivenessAnalysisDone);
+      } else {
+        CU.analyzeDWARFStructure();
+
+        // The registerModuleReference() condition effectively skips
+        // over fully resolved skeleton units. This second pass of
+        // registerModuleReferences doesn't do any new work, but it
+        // will collect top-level errors, which are suppressed. Module
+        // warnings were already displayed in the first iteration.
+        if (registerModuleReference(
+                CU.getOrigUnit().getUnitDIE(), nullptr,
+                [](const DWARFUnit &) {}, 0))
+          CU.setStage(CompileUnit::Stage::PatchesUpdated);
+        else
+          CU.setStage(CompileUnit::Stage::Loaded);
+      }
+    } break;
+
+    case CompileUnit::Stage::Loaded: {
+      // Mark all the DIEs that need to be present in the generated output.
+      // If ODR requested, build type names.
+      if (!DependencyTracker(*this).resolveDependenciesAndMarkLiveness(CU)) {
+        assert(HasNewInterconnectedCUs);
+        return;
+      }
+
+      CU.setStage(CompileUnit::Stage::LivenessAnalysisDone);
+    } break;
+
+    case CompileUnit::Stage::LivenessAnalysisDone:
+
+#ifndef NDEBUG
+      DependencyTracker::verifyKeepChain(CU);
+#endif
+
+      // Clone input compile unit.
+      if (CU.isClangModule() || GlobalData.getOptions().UpdateIndexTablesOnly ||
+          CU.getContaingFile().Addresses->hasValidRelocs()) {
+        if (Error Err = CU.cloneAndEmit(TargetTriple))
+          CU.error(std::move(Err));
+      }
+
+      CU.setStage(CompileUnit::Stage::Cloned);
+      break;
+
+    case CompileUnit::Stage::Cloned:
+      // Update DIEs referencies.
+      CU.updateDieRefPatchesWithClonedOffsets();
+      CU.setStage(CompileUnit::Stage::PatchesUpdated);
+      break;
+
+    case CompileUnit::Stage::PatchesUpdated:
+      // Cleanup resources.
+      CU.cleanupDataAfterClonning();
+      CU.setStage(CompileUnit::Stage::Cleaned);
+      break;
+
+    case CompileUnit::Stage::Cleaned:
+      assert(false);
+      break;
+    }
+  }
+}
+
+Error DWARFLinkerImpl::LinkContext::emitInvariantSections() {
+  if (GlobalData.getOptions().NoOutput)
+    return Error::success();
+
+  getSectionDescriptor(DebugSectionKind::DebugLoc).OS
+      << InputDWARFFile.Dwarf->getDWARFObj().getLocSection().Data;
+  getSectionDescriptor(DebugSectionKind::DebugLocLists).OS
+      << InputDWARFFile.Dwarf->getDWARFObj().getLoclistsSection().Data;
+  getSectionDescriptor(DebugSectionKind::DebugRange).OS
+      << InputDWARFFile.Dwarf->getDWARFObj().getRangesSection().Data;
+  getSectionDescriptor(DebugSectionKind::DebugRngLists).OS
+      << InputDWARFFile.Dwarf->getDWARFObj().getRnglistsSection().Data;
+  getSectionDescriptor(DebugSectionKind::DebugARanges).OS
+      << InputDWARFFile.Dwarf->getDWARFObj().getArangesSection();
+  getSectionDescriptor(DebugSectionKind::DebugFrame).OS
+      << InputDWARFFile.Dwarf->getDWARFObj().getFrameSection().Data;
+  getSectionDescriptor(DebugSectionKind::DebugAddr).OS
+      << InputDWARFFile.Dwarf->getDWARFObj().getAddrSection().Data;
+
+  return Error::success();
+}
+
+Error DWARFLinkerImpl::LinkContext::cloneAndEmitDebugFrame() {
+  if (GlobalData.getOptions().NoOutput)
+    return Error::success();
+
+  if (InputDWARFFile.Dwarf.get() == nullptr)
+    return Error::success();
+
+  const DWARFObject &InputDWARFObj = InputDWARFFile.Dwarf->getDWARFObj();
+
+  StringRef OrigFrameData = InputDWARFObj.getFrameSection().Data;
+  if (OrigFrameData.empty())
+    return Error::success();
+
+  RangesTy AllUnitsRanges;
+  for (std::unique_ptr<CompileUnit> &Unit : CompileUnits) {
+    for (auto CurRange : Unit->getFunctionRanges())
+      AllUnitsRanges.insert(CurRange.Range, CurRange.Value);
+  }
+
+  unsigned SrcAddrSize = InputDWARFObj.getAddressSize();
+
+  SectionDescriptor &OutSection =
+      getSectionDescriptor(DebugSectionKind::DebugFrame);
+
+  DataExtractor Data(OrigFrameData, InputDWARFObj.isLittleEndian(), 0);
+  uint64_t InputOffset = 0;
+
+  // Store the data of the CIEs defined in this object, keyed by their
+  // offsets.
+  DenseMap<uint64_t, StringRef> LocalCIES;
+
+  /// The CIEs that have been emitted in the output section. The actual CIE
+  /// data serves a the key to this StringMap.
+  StringMap<uint32_t> EmittedCIEs;
+
+  while (Data.isValidOffset(InputOffset)) {
+    uint64_t EntryOffset = InputOffset;
+    uint32_t InitialLength = Data.getU32(&InputOffset);
+    if (InitialLength == 0xFFFFFFFF)
+      return createFileError(InputDWARFObj.getFileName(),
+                             createStringError(std::errc::invalid_argument,
+                                               "Dwarf64 bits no supported"));
+
+    uint32_t CIEId = Data.getU32(&InputOffset);
+    if (CIEId == 0xFFFFFFFF) {
+      // This is a CIE, store it.
+      StringRef CIEData = OrigFrameData.substr(EntryOffset, InitialLength + 4);
+      LocalCIES[EntryOffset] = CIEData;
+      // The -4 is to account for the CIEId we just read.
+      InputOffset += InitialLength - 4;
+      continue;
+    }
+
+    uint64_t Loc = Data.getUnsigned(&InputOffset, SrcAddrSize);
+
+    // Some compilers seem to emit frame info that doesn't start at
+    // the function entry point, thus we can't just lookup the address
+    // in the debug map. Use the AddressInfo's range map to see if the FDE
+    // describes something that we can relocate.
+    std::optional<AddressRangeValuePair> Range =
+        AllUnitsRanges.getRangeThatContains(Loc);
+    if (!Range) {
+      // The +4 is to account for the size of the InitialLength field itself.
+      InputOffset = EntryOffset + InitialLength + 4;
+      continue;
+    }
+
+    // This is an FDE, and we have a mapping.
+    // Have we already emitted a corresponding CIE?
+    StringRef CIEData = LocalCIES[CIEId];
+    if (CIEData.empty())
+      return createFileError(
+          InputDWARFObj.getFileName(),
+          createStringError(std::errc::invalid_argument,
+                            "Inconsistent debug_frame content. Dropping."));
+
+    uint64_t OffsetToCIERecord = OutSection.OS.tell();
+
+    // Look if we already emitted a CIE that corresponds to the
+    // referenced one (the CIE data is the key of that lookup).
+    auto IteratorInserted =
+        EmittedCIEs.insert(std::make_pair(CIEData, OffsetToCIERecord));
+    OffsetToCIERecord = IteratorInserted.first->getValue();
+
+    // Emit CIE for this ID if it is not emitted yet.
+    if (IteratorInserted.second)
+      OutSection.OS << CIEData;
+
+    // Remember offset to the FDE record, so that we might update
+    // field referencing CIE record(containing OffsetToCIERecord),
+    // when final offsets are known. OffsetToCIERecord(which is written later)
+    // is local to the current .debug_frame section, it should be updated
+    // with final offset of the .debug_frame section.
+    OutSection.notePatch(
+        DebugOffsetPatch{OutSection.OS.tell() + 4, &OutSection, true});
+
+    // Emit the FDE with updated address and CIE pointer.
+    // (4 + AddrSize) is the size of the CIEId + initial_location
+    // fields that will get reconstructed by emitFDE().
+    unsigned FDERemainingBytes = InitialLength - (4 + SrcAddrSize);
+    emitFDE(OffsetToCIERecord, SrcAddrSize, Loc + Range->Value,
+            OrigFrameData.substr(InputOffset, FDERemainingBytes), OutSection);
+    InputOffset += FDERemainingBytes;
+  }
+
+  return Error::success();
+}
+
+/// Emit a FDE into the debug_frame section. \p FDEBytes
+/// contains the FDE data without the length, CIE offset and address
+/// which will be replaced with the parameter values.
+void DWARFLinkerImpl::LinkContext::emitFDE(uint32_t CIEOffset,
+                                           uint32_t AddrSize, uint64_t Address,
+                                           StringRef FDEBytes,
+                                           SectionDescriptor &Section) {
+  Section.emitIntVal(FDEBytes.size() + 4 + AddrSize, 4);
+  Section.emitIntVal(CIEOffset, 4);
+  Section.emitIntVal(Address, AddrSize);
+  Section.OS.write(FDEBytes.data(), FDEBytes.size());
+}
+
+Error DWARFLinkerImpl::LinkContext::cloneAndEmitPaperTrails() {
+
+  CompileUnits.emplace_back(
+      std::make_unique<CompileUnit>(GlobalData, UniqueUnitID.fetch_add(1), "",
+                                    InputDWARFFile, getUnitForOffset));
+
+  CompileUnit &CU = *CompileUnits.back();
+
+  BumpPtrAllocator Allocator;
+
+  DIEGenerator ParentGenerator(Allocator, CU);
+
+  SectionDescriptor &DebugInfoSection =
+      CU.getSectionDescriptor(DebugSectionKind::DebugInfo);
+  OffsetsPtrVector PatchesOffsets;
+
+  uint64_t CurrentOffset = CU.getHeaderSize();
+  DIE *CUDie =
+      ParentGenerator.createDIE(dwarf::DW_TAG_compile_unit, CurrentOffset);
+  CU.setOutUnitDIE(CUDie);
+
+  DebugInfoSection.notePatchWithOffsetUpdate(
+      DebugStrPatch{{CurrentOffset},
+                    GlobalData.getStringPool().insert("dsymutil").first},
+      PatchesOffsets);
+  CurrentOffset += ParentGenerator
+                       .addStringPlaceholderAttribute(dwarf::DW_AT_producer,
+                                                      dwarf::DW_FORM_strp)
+                       .second;
+
+  CurrentOffset +=
+      ParentGenerator
+          .addInplaceString(dwarf::DW_AT_name, InputDWARFFile.FileName)
+          .second;
+
+  size_t SizeAbbrevNumber = ParentGenerator.finalizeAbbreviations(true);
+  CurrentOffset += SizeAbbrevNumber;
+  for (uint64_t *OffsetPtr : PatchesOffsets)
+    *OffsetPtr += SizeAbbrevNumber;
+  for (const auto &Warning : CU.getContaingFile().Warnings) {
+    PatchesOffsets.clear();
+    DIEGenerator ChildGenerator(Allocator, CU);
+
+    DIE *ChildDie =
+        ChildGenerator.createDIE(dwarf::DW_TAG_constant, CurrentOffset);
+    ParentGenerator.addChild(ChildDie);
+
+    DebugInfoSection.notePatchWithOffsetUpdate(
+        DebugStrPatch{
+            {CurrentOffset},
+            GlobalData.getStringPool().insert("dsymutil_warning").first},
+        PatchesOffsets);
+    CurrentOffset += ChildGenerator
+                         .addStringPlaceholderAttribute(dwarf::DW_AT_name,
+                                                        dwarf::DW_FORM_strp)
+                         .second;
+
+    CurrentOffset +=
+        ChildGenerator
+            .addScalarAttribute(dwarf::DW_AT_artificial, dwarf::DW_FORM_flag, 1)
+            .second;
+
+    DebugInfoSection.notePatchWithOffsetUpdate(
+        DebugStrPatch{{CurrentOffset},
+                      GlobalData.getStringPool().insert(Warning).first},
+        PatchesOffsets);
+    CurrentOffset += ChildGenerator
+                         .addStringPlaceholderAttribute(
+                             dwarf::DW_AT_const_value, dwarf::DW_FORM_strp)
+                         .second;
+
+    SizeAbbrevNumber = ChildGenerator.finalizeAbbreviations(false);
+
+    CurrentOffset += SizeAbbrevNumber;
+    for (uint64_t *OffsetPtr : PatchesOffsets)
+      *OffsetPtr += SizeAbbrevNumber;
+
+    ChildDie->setSize(CurrentOffset - ChildDie->getOffset());
+  }
+
+  CurrentOffset += 1; // End of children
+  CUDie->setSize(CurrentOffset - CUDie->getOffset());
+
+  uint64_t UnitSize = 0;
+  UnitSize += CU.getHeaderSize();
+  UnitSize += CUDie->getSize();
+  CU.setUnitSize(UnitSize);
+
+  if (GlobalData.getOptions().NoOutput)
+    return Error::success();
+
+  if (Error Err = CU.emitDebugInfo(*TargetTriple))
+    return Err;
+
+  return CU.emitAbbreviations();
+}
+
+void DWARFLinkerImpl::glueCompileUnitsAndWriteToTheOutput() {
+  if (GlobalData.getOptions().NoOutput)
+    return;
+
+  // Go through all object files, all compile units and assign
+  // offsets to them.
+  assignOffsets();
+
+  // Patch size/offsets fields according to the assigned CU offsets.
+  patchOffsetsAndSizes();
+
+  // FIXME: Build accelerator tables.
+
+  // Write debug tables from all object files/compile units into the
+  // resulting file.
+  writeDWARFToTheOutput();
+
+  if (GlobalData.getOptions().Statistics)
+    printStatistic();
+}
+
+void DWARFLinkerImpl::printStatistic() {
+
+  // For each object file map how many bytes were emitted.
+  StringMap<DebugInfoSize> SizeByObject;
+
+  for (const std::unique_ptr<LinkContext> &Context : ObjectContexts) {
+    uint64_t AllDebugInfoSectionsSize = 0;
+
+    for (std::unique_ptr<CompileUnit> &CU : Context->CompileUnits)
+      AllDebugInfoSectionsSize +=
+          CU->getSectionDescriptor(DebugSectionKind::DebugInfo)
+              .getContents()
+              .size();
+
+    SizeByObject[Context->InputDWARFFile.FileName].Input =
+        Context->OriginalDebugInfoSize;
+    SizeByObject[Context->InputDWARFFile.FileName].Output =
+        AllDebugInfoSectionsSize;
+  }
+
+  // Create a vector sorted in descending order by output size.
+  std::vector<std::pair<StringRef, DebugInfoSize>> Sorted;
+  for (auto &E : SizeByObject)
+    Sorted.emplace_back(E.first(), E.second);
+  llvm::sort(Sorted, [](auto &LHS, auto &RHS) {
+    return LHS.second.Output > RHS.second.Output;
+  });
+
+  auto ComputePercentange = [](int64_t Input, int64_t Output) -> float {
+    const float Difference = Output - Input;
+    const float Sum = Input + Output;
+    if (Sum == 0)
+      return 0;
+    return (Difference / (Sum / 2));
+  };
+
+  int64_t InputTotal = 0;
+  int64_t OutputTotal = 0;
+  const char *FormatStr = "{0,-45} {1,10}b  {2,10}b {3,8:P}\n";
+
+  // Print header.
+  outs() << ".debug_info section size (in bytes)\n";
+  outs() << "----------------------------------------------------------------"
+            "---------------\n";
+  outs() << "Filename                                           Object       "
+            "  dSYM   Change\n";
+  outs() << "----------------------------------------------------------------"
+            "---------------\n";
+
+  // Print body.
+  for (auto &E : Sorted) {
+    InputTotal += E.second.Input;
+    OutputTotal += E.second.Output;
+    llvm::outs() << formatv(
+        FormatStr, sys::path::filename(E.first).take_back(45), E.second.Input,
+        E.second.Output, ComputePercentange(E.second.Input, E.second.Output));
+  }
+  // Print total and footer.
+  outs() << "----------------------------------------------------------------"
+            "---------------\n";
+  llvm::outs() << formatv(FormatStr, "Total", InputTotal, OutputTotal,
+                          ComputePercentange(InputTotal, OutputTotal));
+  outs() << "----------------------------------------------------------------"
+            "---------------\n\n";
+}
+
+void DWARFLinkerImpl::assignOffsets() {
+  parallel::TaskGroup TGroup;
+  TGroup.spawn([&]() { assignOffsetsToStrings(); });
+  TGroup.spawn([&]() { assignOffsetsToSections(); });
+}
+
+void DWARFLinkerImpl::assignOffsetsToStrings() {
+  size_t CurDebugStrIndex = 1; // start from 1 to take into account zero entry.
+  uint64_t CurDebugStrOffset =
+      1; // start from 1 to take into account zero entry.
+  size_t CurDebugLineStrIndex = 0;
+  uint64_t CurDebugLineStrOffset = 0;
+
+  // To save space we do not create any separate string table.
+  // We use already allocated string patches and assign offsets
+  // to them in the natural order.
+  // ASSUMPTION: strings should be stored into .debug_str/.debug_line_str
+  // sections in the same order as they were assigned offsets.
+
+  forEachSectionsSet([&](OutputSections &SectionsSet) {
+    SectionsSet.forEach([&](SectionDescriptor &OutSection) {
+      assignOffsetsToStringsImpl(OutSection.ListDebugStrPatch, CurDebugStrIndex,
+                                 CurDebugStrOffset, DebugStrStrings);
+
+      assignOffsetsToStringsImpl(OutSection.ListDebugLineStrPatch,
+                                 CurDebugLineStrIndex, CurDebugLineStrOffset,
+                                 DebugLineStrStrings);
+    });
+  });
+}
+
+template <typename PatchTy>
+void DWARFLinkerImpl::assignOffsetsToStringsImpl(
+    ArrayList<PatchTy> &Patches, size_t &IndexAccumulator,
+    uint64_t &OffsetAccumulator,
+    StringEntryToDwarfStringPoolEntryMap &StringsForEmission) {
+
+  // Enumerates all patches, adds string into the
+  // StringEntry->DwarfStringPoolEntry map, assign offset and index to the
+  // string if it is not indexed yet.
+  Patches.forEach([&](PatchTy &Patch) {
+    DwarfStringPoolEntryWithExtString *Entry =
+        StringsForEmission.add(Patch.String);
+    assert(Entry != nullptr);
+
+    if (!Entry->isIndexed()) {
+      Entry->Offset = OffsetAccumulator;
+      OffsetAccumulator += Entry->String.size() + 1;
+      Entry->Index = IndexAccumulator++;
+    }
+  });
+}
+
+void DWARFLinkerImpl::assignOffsetsToSections() {
+  std::array<uint64_t, SectionKindsNum> SectionSizesAccumulator = {0};
+
+  forEachSectionsSet([&](OutputSections &UnitSections) {
+    UnitSections.assignSectionsOffsetAndAccumulateSize(SectionSizesAccumulator);
+  });
+}
+
+void DWARFLinkerImpl::forEachSectionsSet(
+    function_ref<void(OutputSections &)> SectionsSetHandler) {
+  // Handle all modules first(before regular compilation units).
+  for (const std::unique_ptr<LinkContext> &Context : ObjectContexts)
+    for (LinkContext::RefModuleUnit &ModuleUnit : Context->ModulesCompileUnits)
+      SectionsSetHandler(*ModuleUnit.Unit);
+
+  for (const std::unique_ptr<LinkContext> &Context : ObjectContexts) {
+    // Handle common sections.
+    SectionsSetHandler(*Context);
+
+    // Handle compilation units.
+    for (std::unique_ptr<CompileUnit> &CU : Context->CompileUnits)
+      SectionsSetHandler(*CU);
+  }
+}
+
+void DWARFLinkerImpl::patchOffsetsAndSizes() {
+  forEachSectionsSet([&](OutputSections &SectionsSet) {
+    SectionsSet.forEach([&](SectionDescriptor &OutSection) {
+      SectionsSet.applyPatches(OutSection, DebugStrStrings,
+                               DebugLineStrStrings);
+    });
+  });
+}
+
+void DWARFLinkerImpl::writeDWARFToTheOutput() {
+  bool HasAbbreviations = false;
+  uint64_t DebugStrNextOffset = 0;
+  uint64_t DebugLineStrNextOffset = 0;
+
+  // Emit zero length string. Accelerator tables does not work correctly
+  // if the first string is not zero length string.
+  TheDwarfEmitter->emitZeroString();
+  DebugStrNextOffset++;
+
+  forEachSectionsSet([&](OutputSections &Sections) {
+    Sections.forEach([&](SectionDescriptor &OutSection) {
+      if (OutSection.getContents().empty())
+        return;
+
+      if (!HasAbbreviations &&
+          OutSection.getKind() == DebugSectionKind::DebugAbbrev) {
+        HasAbbreviations = true;
+      }
+
+      // Emit section content.
+      TheDwarfEmitter->emitSectionContents(OutSection.getContents(),
+                                           OutSection.getName());
+
+      // Pass through string patches and emit them in order.
+      if (!OutSection.ListDebugStrPatch.empty())
+        TheDwarfEmitter->emitStrings(OutSection.ListDebugStrPatch,
+                                     DebugStrStrings, DebugStrNextOffset);
+
+      if (!OutSection.ListDebugLineStrPatch.empty())
+        TheDwarfEmitter->emitLineStrings(OutSection.ListDebugLineStrPatch,
+                                         DebugLineStrStrings,
+                                         DebugLineStrNextOffset);
+    });
+  });
+
+  if (!HasAbbreviations) {
+    const SmallVector<std::unique_ptr<DIEAbbrev>> Abbreviations;
+    TheDwarfEmitter->emitAbbrevs(Abbreviations, 3);
+  }
+}
+
 } // end of namespace dwarflinker_parallel
 } // namespace llvm

llvm/lib/DWARFLinkerParallel/DWARFLinkerUnit.h

 //===- DWARFLinkerUnit.h ----------------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIB_DWARFLINKERPARALLEL_DWARFLINKERUNIT_H
 #define LLVM_LIB_DWARFLINKERPARALLEL_DWARFLINKERUNIT_H
 
+#include "DWARFLinkerGlobalData.h"
 #include "OutputSections.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/CodeGen/DIE.h"
+#include "llvm/DWARFLinkerParallel/DWARFLinker.h"
 #include "llvm/DWARFLinkerParallel/StringPool.h"
 #include "llvm/DebugInfo/DWARF/DWARFUnit.h"
 #include "llvm/Support/LEB128.h"
 
 namespace llvm {
 namespace dwarflinker_parallel {
 
-using UnitMessageHandlerTy = function_ref<void(
-    const Twine &Error, StringRef Context, const DWARFDie *DIE)>;
-
-/// Each unit keeps output data as a file with debug tables
-/// corresponding to the concrete unit.
-using OutTablesFileTy = SmallString<0>;
+class DwarfUnit;
+using MacroOffset2UnitMapTy = DenseMap<uint64_t, DwarfUnit *>;
 
 /// Base class for all Dwarf units(Compile unit/Type table unit).
 class DwarfUnit : public OutputSections {
 public:
   virtual ~DwarfUnit() {}
-  DwarfUnit(unsigned ID, StringRef ClangModuleName,
-            UnitMessageHandlerTy WarningHandler)
-      : ID(ID), ClangModuleName(ClangModuleName),
-        WarningHandler(WarningHandler) {
-    FormParams.Version = 4;
-    FormParams.Format = dwarf::DWARF32;
-    FormParams.AddrSize = 4;
+  DwarfUnit(LinkingGlobalData &GlobalData, unsigned ID,
+            StringRef ClangModuleName)
+      : GlobalData(GlobalData), ID(ID), ClangModuleName(ClangModuleName),
+        OutUnitDIE(nullptr) {
+    setGlobalData(&GlobalData);
   }
 
-  /// Endiannes for the compile unit.
-  support::endianness getEndianness() const { return Endianess; }
-
-  /// Return DWARF version.
-  uint16_t getVersion() const { return FormParams.Version; }
-
-  /// Return size of header of debug_info table.
-  uint16_t getHeaderSize() const { return FormParams.Version >= 5 ? 12 : 11; }
-
-  /// Return size of address.
-  uint8_t getAddressByteSize() const { return FormParams.AddrSize; }
-
-  /// Return size of reference.
-  uint8_t getRefAddrByteSize() const { return FormParams.getRefAddrByteSize(); }
-
-  /// Return format of the Dwarf(DWARF32 or DWARF64).
-  /// TODO: DWARF64 is not currently supported.
-  dwarf::DwarfFormat getDwarfFormat() const { return FormParams.Format; }
-
   /// Unique id of the unit.
   unsigned getUniqueID() const { return ID; }
 
   /// Return language of this unit.
   uint16_t getLanguage() const { return Language; }
 
   /// Set size of this(newly generated) compile unit.
   void setUnitSize(uint64_t UnitSize) { this->UnitSize = UnitSize; }
 
   /// Returns size of this(newly generated) compile unit.
   uint64_t getUnitSize() const { return UnitSize; }
 
   /// Returns this unit name.
   StringRef getUnitName() const { return UnitName; }
 
   /// Return the DW_AT_LLVM_sysroot of the compile unit or an empty StringRef.
   StringRef getSysRoot() { return SysRoot; }
 
-  /// Create a Die for this unit.
-  void setOutputDIE(DIE *UnitDie) { NewUnit = UnitDie; }
-
-  /// Return Die for this compile unit.
-  DIE *getOutputUnitDIE() const { return NewUnit; }
-
   /// Return true if this compile unit is from Clang module.
   bool isClangModule() const { return !ClangModuleName.empty(); }
 
   /// Return Clang module name;
   const std::string &getClangModuleName() const { return ClangModuleName; }
 
-  /// Returns generated file keeping debug tables for this compile unit.
-  OutTablesFileTy &getOutDwarfBits() { return OutDebugInfoBits; }
+  /// Return global data.
+  LinkingGlobalData &getGlobalData() { return GlobalData; }
+
+  /// Returns true if unit is inter-connected(it references/referenced by other
+  /// unit).
+  bool isInterconnectedCU() const { return IsInterconnectedCU; }
+
+  /// Mark this unit as inter-connected(it references/referenced by other unit).
+  void setInterconnectedCU() { IsInterconnectedCU = true; }
+
+  /// Adds \p Abbrev into unit`s abbreviation table.
+  void assignAbbrev(DIEAbbrev &Abbrev);
+
+  /// Returns abbreviations for this compile unit.
+  const std::vector<std::unique_ptr<DIEAbbrev>> &getAbbreviations() const {
+    return Abbreviations;
+  }
 
-  /// Erases generated file keeping debug tables for this compile unit.
-  void eraseDwarfBits() { OutDebugInfoBits = OutTablesFileTy(); }
+  /// Returns output unit DIE.
+  DIE *getOutUnitDIE() { return OutUnitDIE; }
 
-  MCSymbol *getLabelBegin() { return LabelBegin; }
-  void setLabelBegin(MCSymbol *S) { LabelBegin = S; }
+  /// Set output unit DIE.
+  void setOutUnitDIE(DIE *UnitDie) { OutUnitDIE = UnitDie; }
 
-  /// Error reporting methods.
+  /// \defgroup Methods used to emit unit's debug info:
+  ///
   /// @{
+  /// Emit unit's abbreviations.
+  Error emitAbbreviations();
 
-  void reportWarning(const Twine &Warning,
-                     const DWARFDie *Die = nullptr) const {
-    if (WarningHandler)
-      WarningHandler(Warning, getUnitName(), Die);
-  }
-  void reportWarning(Error Warning) const {
-    handleAllErrors(std::move(Warning), [&](ErrorInfoBase &Info) {
-      if (WarningHandler)
-        WarningHandler(Info.message(), getUnitName(), nullptr);
-    });
-  }
+  /// Emit .debug_info section for unit DIEs.
+  Error emitDebugInfo(Triple &TargetTriple);
+
+  /// Emit .debug_line section.
+  Error emitDebugLine(Triple &TargetTriple,
+                      const DWARFDebugLine::LineTable &OutLineTable);
   /// @}
 
   /// This structure keeps fields which would be used for creating accelerator
   /// table.
   struct AccelInfo {
     AccelInfo(StringEntry *Name, const DIE *Die, bool SkipPubSection = false);
     AccelInfo(StringEntry *Name, const DIE *Die, uint32_t QualifiedNameHash,
               bool ObjCClassIsImplementation);
struct AccelInfo {
 
     /// Is this an ObjC class implementation?
     bool ObjcClassImplementation = false;
 
     /// Cloned Die containing acceleration info.
     const DIE *Die = nullptr;
   };
 
+  /// \defgroup Methods used for reporting warnings and errors:
+  ///
+  /// @{
+  void warn(const Twine &Warning) { GlobalData.warn(Warning, getUnitName()); }
+
+  void error(const Twine &Err) { GlobalData.warn(Err, getUnitName()); }
+  /// @}
+
 protected:
-  /// Unique ID for the unit.
-  unsigned ID = 0;
+  /// Emit single abbreviation entry.
+  void emitDwarfAbbrevEntry(const DIEAbbrev &Abbrev,
+                            SectionDescriptor &AbbrevSection);
 
-  /// Properties of the unit.
-  dwarf::FormParams FormParams;
+  /// Linking global data.
+  LinkingGlobalData &GlobalData;
 
-  /// DIE for newly generated compile unit.
-  DIE *NewUnit = nullptr;
+  /// Unique ID for the unit.
+  unsigned ID = 0;
 
   /// The DW_AT_language of this unit.
   uint16_t Language = 0;
 
   /// The name of this unit.
   std::string UnitName;
 
   /// The DW_AT_LLVM_sysroot of this unit.
   std::string SysRoot;
 
   /// If this is a Clang module, this holds the module's name.
   std::string ClangModuleName;
 
   uint64_t UnitSize = 0;
 
-  /// Elf file containg generated debug tables for this compile unit.
-  OutTablesFileTy OutDebugInfoBits;
-
-  /// Endiannes for this compile unit.
-  support::endianness Endianess = support::endianness::little;
-
-  MCSymbol *LabelBegin = nullptr;
-
   /// true if current unit references_to/is_referenced by other unit.
   std::atomic<bool> IsInterconnectedCU = {false};
 
-  UnitMessageHandlerTy WarningHandler;
+  /// FoldingSet that uniques the abbreviations.
+  FoldingSet<DIEAbbrev> AbbreviationsSet;
+
+  /// Storage for the unique Abbreviations.
+  std::vector<std::unique_ptr<DIEAbbrev>> Abbreviations;
+
+  /// Output unit DIE.
+  DIE *OutUnitDIE = nullptr;
 };
 
 } // end of namespace dwarflinker_parallel
 } // end namespace llvm
 
 #endif // LLVM_LIB_DWARFLINKERPARALLEL_DWARFLINKERUNIT_H

llvm/lib/DWARFLinkerParallel/DWARFLinkerUnit.cpp

+//===- DWARFLinkerUnit.cpp ------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "DWARFLinkerUnit.h"
+#include "DWARFEmitterImpl.h"
+#include "DebugLineSectionEmitter.h"
+
+namespace llvm {
+namespace dwarflinker_parallel {
+
+void DwarfUnit::assignAbbrev(DIEAbbrev &Abbrev) {
+  // Check the set for priors.
+  FoldingSetNodeID ID;
+  Abbrev.Profile(ID);
+  void *InsertToken;
+
+  DIEAbbrev *InSet = AbbreviationsSet.FindNodeOrInsertPos(ID, InsertToken);
+  // If it's newly added.
+  if (InSet) {
+    // Assign existing abbreviation number.
+    Abbrev.setNumber(InSet->getNumber());
+  } else {
+    // Add to abbreviation list.
+    Abbreviations.push_back(
+        std::make_unique<DIEAbbrev>(Abbrev.getTag(), Abbrev.hasChildren()));
+    for (const auto &Attr : Abbrev.getData())
+      Abbreviations.back()->AddAttribute(Attr);
+    AbbreviationsSet.InsertNode(Abbreviations.back().get(), InsertToken);
+    // Assign the unique abbreviation number.
+    Abbrev.setNumber(Abbreviations.size());
+    Abbreviations.back()->setNumber(Abbreviations.size());
+  }
+}
+
+Error DwarfUnit::emitAbbreviations() {
+  const std::vector<std::unique_ptr<DIEAbbrev>> &Abbrevs = getAbbreviations();
+  if (Abbrevs.empty())
+    return Error::success();
+
+  SectionDescriptor &AbbrevSection =
+      getSectionDescriptor(DebugSectionKind::DebugAbbrev);
+
+  // For each abbreviation.
+  for (const auto &Abbrev : Abbrevs)
+    emitDwarfAbbrevEntry(*Abbrev, AbbrevSection);
+
+  // Mark end of abbreviations.
+  encodeULEB128(0, AbbrevSection.OS);
+
+  return Error::success();
+}
+
+void DwarfUnit::emitDwarfAbbrevEntry(const DIEAbbrev &Abbrev,
+                                     SectionDescriptor &AbbrevSection) {
+  // Emit the abbreviations code (base 1 index.)
+  encodeULEB128(Abbrev.getNumber(), AbbrevSection.OS);
+
+  // Emit the abbreviations data.
+  // Emit its Dwarf tag type.
+  encodeULEB128(Abbrev.getTag(), AbbrevSection.OS);
+
+  // Emit whether it has children DIEs.
+  encodeULEB128((unsigned)Abbrev.hasChildren(), AbbrevSection.OS);
+
+  // For each attribute description.
+  const SmallVectorImpl<DIEAbbrevData> &Data = Abbrev.getData();
+  for (unsigned i = 0, N = Data.size(); i < N; ++i) {
+    const DIEAbbrevData &AttrData = Data[i];
+
+    // Emit attribute type.
+    encodeULEB128(AttrData.getAttribute(), AbbrevSection.OS);
+
+    // Emit form type.
+    encodeULEB128(AttrData.getForm(), AbbrevSection.OS);
+
+    // Emit value for DW_FORM_implicit_const.
+    if (AttrData.getForm() == dwarf::DW_FORM_implicit_const)
+      encodeSLEB128(AttrData.getValue(), AbbrevSection.OS);
+  }
+
+  // Mark end of abbreviation.
+  encodeULEB128(0, AbbrevSection.OS);
+  encodeULEB128(0, AbbrevSection.OS);
+}
+
+Error DwarfUnit::emitDebugInfo(Triple &TargetTriple) {
+  DIE *OutUnitDIE = getOutUnitDIE();
+  if (OutUnitDIE == nullptr)
+    return Error::success();
+
+  // FIXME: Remove dependence on DwarfEmitterImpl/AsmPrinter and emit DIEs
+  // directly.
+
+  SectionDescriptor &OutSection =
+      getSectionDescriptor(DebugSectionKind::DebugInfo);
+  DwarfEmitterImpl Emitter(DWARFLinker::OutputFileType::Object, OutSection.OS);
+  if (Error Err = Emitter.init(TargetTriple, "__DWARF"))
+    return Err;
+
+  // Emit compile unit header.
+  Emitter.emitCompileUnitHeader(*this);
+  size_t OffsetToAbbreviationTableOffset =
+      (getFormParams().Version >= 5) ? 8 : 6;
+  OutSection.notePatch(
+      DebugOffsetPatch{OffsetToAbbreviationTableOffset,
+                       &getSectionDescriptor(DebugSectionKind::DebugAbbrev)});
+
+  // Emit DIEs.
+  Emitter.emitDIE(*OutUnitDIE);
+  Emitter.finish();
+
+  // Set start offset ans size for .debug_info section.
+  OutSection.setSizesForSectionCreatedByAsmPrinter();
+  return Error::success();
+}
+
+Error DwarfUnit::emitDebugLine(Triple &TargetTriple,
+                               const DWARFDebugLine::LineTable &OutLineTable) {
+  DebugLineSectionEmitter DebugLineEmitter(TargetTriple, *this);
+
+  return DebugLineEmitter.emit(OutLineTable);
+}
+
+} // end of namespace dwarflinker_parallel
+} // end of namespace llvm

llvm/lib/DWARFLinkerParallel/DebugLineSectionEmitter.h

+//===- DebugLineSectionEmitter.h --------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_DWARFLINKERPARALLEL_DEBUGLINESECTIONEMITTER_H
+#define LLVM_LIB_DWARFLINKERPARALLEL_DEBUGLINESECTIONEMITTER_H
+
+#include "DWARFEmitterImpl.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/DWARFLinkerParallel/AddressesMap.h"
+#include "llvm/DWARFLinkerParallel/DWARFLinker.h"
+#include "llvm/DebugInfo/DWARF/DWARFObject.h"
+#include "llvm/MC/MCTargetOptionsCommandFlags.h"
+#include "llvm/MC/TargetRegistry.h"
+
+namespace llvm {
+namespace dwarflinker_parallel {
+
+/// This class emits specified line table into the .debug_line section.
+class DebugLineSectionEmitter {
+public:
+  DebugLineSectionEmitter(const Triple &TheTriple, DwarfUnit &U)
+      : TheTriple(TheTriple), U(U) {}
+
+  Error emit(const DWARFDebugLine::LineTable &LineTable) {
+    // FIXME: remove dependence on MCDwarfLineAddr::encode.
+    // As we reuse MCDwarfLineAddr::encode, we need to create/initialize
+    // some MC* classes.
+    if (Error Err = init(TheTriple))
+      return Err;
+
+    // Get descriptor for output .debug_line section.
+    SectionDescriptor &OutSection =
+        U.getSectionDescriptor(DebugSectionKind::DebugLine);
+
+    // unit_length.
+    OutSection.emitUnitLength(0xBADDEF);
+    uint64_t OffsetAfterUnitLength = OutSection.OS.tell();
+
+    // Emit prologue.
+    emitLineTablePrologue(LineTable.Prologue, OutSection);
+
+    // Emit rows.
+    emitLineTableRows(LineTable, OutSection);
+    uint64_t OffsetAfterEnd = OutSection.OS.tell();
+
+    // Update unit length field with actual length value.
+    assert(OffsetAfterUnitLength -
+               OutSection.getFormParams().getDwarfOffsetByteSize() <
+           OffsetAfterUnitLength);
+    OutSection.apply(OffsetAfterUnitLength -
+                         OutSection.getFormParams().getDwarfOffsetByteSize(),
+                     dwarf::DW_FORM_sec_offset,
+                     OffsetAfterEnd - OffsetAfterUnitLength);
+
+    return Error::success();
+  }
+
+private:
+  Error init(Triple TheTriple) {
+    std::string ErrorStr;
+    std::string TripleName;
+
+    // Get the target.
+    const Target *TheTarget =
+        TargetRegistry::lookupTarget(TripleName, TheTriple, ErrorStr);
+    if (!TheTarget)
+      return createStringError(std::errc::invalid_argument, ErrorStr.c_str());
+    TripleName = TheTriple.getTriple();
+
+    // Create all the MC Objects.
+    MRI.reset(TheTarget->createMCRegInfo(TripleName));
+    if (!MRI)
+      return createStringError(std::errc::invalid_argument,
+                               "no register info for target %s",
+                               TripleName.c_str());
+
+    MCTargetOptions MCOptions = mc::InitMCTargetOptionsFromFlags();
+    MAI.reset(TheTarget->createMCAsmInfo(*MRI, TripleName, MCOptions));
+    if (!MAI)
+      return createStringError(std::errc::invalid_argument,
+                               "no asm info for target %s", TripleName.c_str());
+
+    MSTI.reset(TheTarget->createMCSubtargetInfo(TripleName, "", ""));
+    if (!MSTI)
+      return createStringError(std::errc::invalid_argument,
+                               "no subtarget info for target %s",
+                               TripleName.c_str());
+
+    MC.reset(new MCContext(TheTriple, MAI.get(), MRI.get(), MSTI.get(), nullptr,
+                           nullptr, true, "__DWARF"));
+
+    return Error::success();
+  }
+
+  void emitLineTablePrologue(const DWARFDebugLine::Prologue &P,
+                             SectionDescriptor &Section) {
+    // version (uhalf).
+    Section.emitIntVal(P.getVersion(), 2);
+    if (P.getVersion() == 5) {
+      // address_size (ubyte).
+      Section.emitIntVal(P.getAddressSize(), 1);
+
+      // segment_selector_size (ubyte).
+      Section.emitIntVal(P.SegSelectorSize, 1);
+    }
+
+    // header_length.
+    Section.emitOffset(0xBADDEF);
+
+    uint64_t OffsetAfterPrologueLength = Section.OS.tell();
+    emitLineTableProloguePayload(P, Section);
+    uint64_t OffsetAfterPrologueEnd = Section.OS.tell();
+
+    // Update prologue length field with actual length value.
+    Section.apply(OffsetAfterPrologueLength -
+                      Section.getFormParams().getDwarfOffsetByteSize(),
+                  dwarf::DW_FORM_sec_offset,
+                  OffsetAfterPrologueEnd - OffsetAfterPrologueLength);
+  }
+
+  void
+  emitLineTablePrologueV2IncludeAndFileTable(const DWARFDebugLine::Prologue &P,
+                                             SectionDescriptor &Section) {
+    // include_directories (sequence of path names).
+    for (const DWARFFormValue &Include : P.IncludeDirectories) {
+      std::optional<const char *> IncludeStr = dwarf::toString(Include);
+      if (!IncludeStr) {
+        U.warn("cann't read string from line table.");
+        return;
+      }
+
+      Section.emitString(Include.getForm(), *IncludeStr);
+    }
+    // The last entry is followed by a single null byte.
+    Section.emitIntVal(0, 1);
+
+    // file_names (sequence of file entries).
+    for (const DWARFDebugLine::FileNameEntry &File : P.FileNames) {
+      std::optional<const char *> FileNameStr = dwarf::toString(File.Name);
+      if (!FileNameStr) {
+        U.warn("cann't read string from line table.");
+        return;
+      }
+
+      // A null-terminated string containing the full or relative path name of a
+      // source file.
+      Section.emitString(File.Name.getForm(), *FileNameStr);
+      // An unsigned LEB128 number representing the directory index of a
+      // directory in the include_directories section.
+      encodeULEB128(File.DirIdx, Section.OS);
+      // An unsigned LEB128 number representing the (implementation-defined)
+      // time of last modification for the file, or 0 if not available.
+      encodeULEB128(File.ModTime, Section.OS);
+      // An unsigned LEB128 number representing the length in bytes of the file,
+      // or 0 if not available.
+      encodeULEB128(File.Length, Section.OS);
+    }
+    // The last entry is followed by a single null byte.
+    Section.emitIntVal(0, 1);
+  }
+
+  void
+  emitLineTablePrologueV5IncludeAndFileTable(const DWARFDebugLine::Prologue &P,
+                                             SectionDescriptor &Section) {
+    if (P.IncludeDirectories.empty()) {
+      // directory_entry_format_count(ubyte).
+      Section.emitIntVal(0, 1);
+    } else {
+      // directory_entry_format_count(ubyte).
+      Section.emitIntVal(1, 1);
+
+      // directory_entry_format (sequence of ULEB128 pairs).
+      encodeULEB128(dwarf::DW_LNCT_path, Section.OS);
+      encodeULEB128(P.IncludeDirectories[0].getForm(), Section.OS);
+    }
+
+    // directories_count (ULEB128).
+    encodeULEB128(P.IncludeDirectories.size(), Section.OS);
+    // directories (sequence of directory names).
+    for (auto Include : P.IncludeDirectories) {
+      std::optional<const char *> IncludeStr = dwarf::toString(Include);
+      if (!IncludeStr) {
+        U.warn("cann't read string from line table.");
+        return;
+      }
+
+      Section.emitString(Include.getForm(), *IncludeStr);
+    }
+
+    if (P.FileNames.empty()) {
+      // file_name_entry_format_count (ubyte).
+      Section.emitIntVal(0, 1);
+    } else {
+      // file_name_entry_format_count (ubyte).
+      Section.emitIntVal(2, 1);
+
+      // file_name_entry_format (sequence of ULEB128 pairs).
+      encodeULEB128(dwarf::DW_LNCT_path, Section.OS);
+      encodeULEB128(P.FileNames[0].Name.getForm(), Section.OS);
+
+      encodeULEB128(dwarf::DW_LNCT_directory_index, Section.OS);
+      encodeULEB128(dwarf::DW_FORM_data1, Section.OS);
+    }
+
+    // file_names_count (ULEB128).
+    encodeULEB128(P.FileNames.size(), Section.OS);
+
+    // file_names (sequence of file name entries).
+    for (auto File : P.FileNames) {
+      std::optional<const char *> FileNameStr = dwarf::toString(File.Name);
+      if (!FileNameStr) {
+        U.warn("cann't read string from line table.");
+        return;
+      }
+
+      // A null-terminated string containing the full or relative path name of a
+      // source file.
+      Section.emitString(File.Name.getForm(), *FileNameStr);
+      Section.emitIntVal(File.DirIdx, 1);
+    }
+  }
+
+  void emitLineTableProloguePayload(const DWARFDebugLine::Prologue &P,
+                                    SectionDescriptor &Section) {
+    // minimum_instruction_length (ubyte).
+    Section.emitIntVal(P.MinInstLength, 1);
+    if (P.FormParams.Version >= 4) {
+      // maximum_operations_per_instruction (ubyte).
+      Section.emitIntVal(P.MaxOpsPerInst, 1);
+    }
+    // default_is_stmt (ubyte).
+    Section.emitIntVal(P.DefaultIsStmt, 1);
+    // line_base (sbyte).
+    Section.emitIntVal(P.LineBase, 1);
+    // line_range (ubyte).
+    Section.emitIntVal(P.LineRange, 1);
+    // opcode_base (ubyte).
+    Section.emitIntVal(P.OpcodeBase, 1);
+
+    // standard_opcode_lengths (array of ubyte).
+    for (auto Length : P.StandardOpcodeLengths)
+      Section.emitIntVal(Length, 1);
+
+    if (P.FormParams.Version < 5)
+      emitLineTablePrologueV2IncludeAndFileTable(P, Section);
+    else
+      emitLineTablePrologueV5IncludeAndFileTable(P, Section);
+  }
+
+  void emitLineTableRows(const DWARFDebugLine::LineTable &LineTable,
+                         SectionDescriptor &Section) {
+
+    MCDwarfLineTableParams Params;
+    Params.DWARF2LineOpcodeBase = LineTable.Prologue.OpcodeBase;
+    Params.DWARF2LineBase = LineTable.Prologue.LineBase;
+    Params.DWARF2LineRange = LineTable.Prologue.LineRange;
+
+    SmallString<128> EncodingBuffer;
+
+    if (LineTable.Rows.empty()) {
+      // We only have the dummy entry, dsymutil emits an entry with a 0
+      // address in that case.
+      MCDwarfLineAddr::encode(*MC, Params, std::numeric_limits<int64_t>::max(),
+                              0, EncodingBuffer);
+      Section.OS.write(EncodingBuffer.c_str(), EncodingBuffer.size());
+      return;
+    }
+
+    // Line table state machine fields
+    unsigned FileNum = 1;
+    unsigned LastLine = 1;
+    unsigned Column = 0;
+    unsigned IsStatement = 1;
+    unsigned Isa = 0;
+    uint64_t Address = -1ULL;
+
+    unsigned RowsSinceLastSequence = 0;
+
+    for (const DWARFDebugLine::Row &Row : LineTable.Rows) {
+      int64_t AddressDelta;
+      if (Address == -1ULL) {
+        Section.emitIntVal(dwarf::DW_LNS_extended_op, 1);
+        encodeULEB128(Section.getFormParams().AddrSize + 1, Section.OS);
+        Section.emitIntVal(dwarf::DW_LNE_set_address, 1);
+        Section.emitIntVal(Row.Address.Address,
+                           Section.getFormParams().AddrSize);
+        AddressDelta = 0;
+      } else {
+        AddressDelta =
+            (Row.Address.Address - Address) / LineTable.Prologue.MinInstLength;
+      }
+
+      // FIXME: code copied and transformed from
+      // MCDwarf.cpp::EmitDwarfLineTable. We should find a way to share this
+      // code, but the current compatibility requirement with classic dsymutil
+      // makes it hard. Revisit that once this requirement is dropped.
+
+      if (FileNum != Row.File) {
+        FileNum = Row.File;
+        Section.emitIntVal(dwarf::DW_LNS_set_file, 1);
+        encodeULEB128(FileNum, Section.OS);
+      }
+      if (Column != Row.Column) {
+        Column = Row.Column;
+        Section.emitIntVal(dwarf::DW_LNS_set_column, 1);
+        encodeULEB128(Column, Section.OS);
+      }
+
+      // FIXME: We should handle the discriminator here, but dsymutil doesn't
+      // consider it, thus ignore it for now.
+
+      if (Isa != Row.Isa) {
+        Isa = Row.Isa;
+        Section.emitIntVal(dwarf::DW_LNS_set_isa, 1);
+        encodeULEB128(Isa, Section.OS);
+      }
+      if (IsStatement != Row.IsStmt) {
+        IsStatement = Row.IsStmt;
+        Section.emitIntVal(dwarf::DW_LNS_negate_stmt, 1);
+      }
+      if (Row.BasicBlock)
+        Section.emitIntVal(dwarf::DW_LNS_set_basic_block, 1);
+
+      if (Row.PrologueEnd)
+        Section.emitIntVal(dwarf::DW_LNS_set_prologue_end, 1);
+
+      if (Row.EpilogueBegin)
+        Section.emitIntVal(dwarf::DW_LNS_set_epilogue_begin, 1);
+
+      int64_t LineDelta = int64_t(Row.Line) - LastLine;
+      if (!Row.EndSequence) {
+        MCDwarfLineAddr::encode(*MC, Params, LineDelta, AddressDelta,
+                                EncodingBuffer);
+        Section.OS.write(EncodingBuffer.c_str(), EncodingBuffer.size());
+        EncodingBuffer.resize(0);
+        Address = Row.Address.Address;
+        LastLine = Row.Line;
+        RowsSinceLastSequence++;
+      } else {
+        if (LineDelta) {
+          Section.emitIntVal(dwarf::DW_LNS_advance_line, 1);
+          encodeSLEB128(LineDelta, Section.OS);
+        }
+        if (AddressDelta) {
+          Section.emitIntVal(dwarf::DW_LNS_advance_pc, 1);
+          encodeULEB128(AddressDelta, Section.OS);
+        }
+        MCDwarfLineAddr::encode(*MC, Params,
+                                std::numeric_limits<int64_t>::max(), 0,
+                                EncodingBuffer);
+        Section.OS.write(EncodingBuffer.c_str(), EncodingBuffer.size());
+        EncodingBuffer.resize(0);
+        Address = -1ULL;
+        LastLine = FileNum = IsStatement = 1;
+        RowsSinceLastSequence = Column = Isa = 0;
+      }
+    }
+
+    if (RowsSinceLastSequence) {
+      MCDwarfLineAddr::encode(*MC, Params, std::numeric_limits<int64_t>::max(),
+                              0, EncodingBuffer);
+      Section.OS.write(EncodingBuffer.c_str(), EncodingBuffer.size());
+      EncodingBuffer.resize(0);
+    }
+  }
+
+  Triple TheTriple;
+  DwarfUnit &U;
+
+  std::unique_ptr<MCRegisterInfo> MRI;
+  std::unique_ptr<MCAsmInfo> MAI;
+  std::unique_ptr<MCContext> MC;
+  std::unique_ptr<MCSubtargetInfo> MSTI;
+};
+
+} // end of namespace dwarflinker_parallel
+} // end namespace llvm
+
+#endif // LLVM_LIB_DWARFLINKERPARALLEL_DEBUGLINESECTIONEMITTER_H

llvm/lib/DWARFLinkerParallel/DependencyTracker.h

+//===- "DependencyTracker.h" ------------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_DWARFLINKERPARALLEL_DEPENDENCYTRACKER_H
+#define LLVM_LIB_DWARFLINKERPARALLEL_DEPENDENCYTRACKER_H
+
+#include "DWARFLinkerCompileUnit.h"
+#include "DWARFLinkerImpl.h"
+#include "llvm/ADT/SmallVector.h"
+
+namespace llvm {
+class DWARFDebugInfoEntry;
+class DWARFDie;
+
+namespace dwarflinker_parallel {
+
+/// This class discovers DIEs dependencies and marks "live" DIEs.
+class DependencyTracker {
+public:
+  DependencyTracker(DWARFLinkerImpl::LinkContext &Context) : Context(Context) {}
+
+  /// Recursively walk the \p DIE tree and look for DIEs to keep. Store that
+  /// information in \p CU's DIEInfo.
+  ///
+  /// This function is the entry point of the DIE selection algorithm. It is
+  /// expected to walk the DIE tree and(through the mediation of
+  /// Context.File.Addresses) ask for relocation adjustment value on each
+  /// DIE that might be a 'root DIE'.
+  ///
+  /// Returns true if all dependencies are correctly discovered. Inter-CU
+  /// dependencies cannot be discovered if referenced CU is not analyzed yet.
+  /// If that is the case this method returns false.
+  bool resolveDependenciesAndMarkLiveness(CompileUnit &CU);
+
+  /// Recursively walk the \p DIE tree and check "keepness" information.
+  /// It is an error if parent node does not have "keep" flag, while
+  /// child have one. This function dump error at stderr in that case.
+#ifndef NDEBUG
+  static void verifyKeepChain(CompileUnit &CU);
+#endif
+
+protected:
+  struct RootEntryTy {
+    RootEntryTy(CompileUnit &CU, const DWARFDebugInfoEntry *RootEntry)
+        : CU(CU), RootEntry(RootEntry) {}
+
+    // Compile unit keeping root entry.
+    CompileUnit &CU;
+
+    // Root entry.
+    const DWARFDebugInfoEntry *RootEntry;
+  };
+
+  using RootEntriesListTy = SmallVector<RootEntryTy>;
+
+  /// This function navigates DIEs tree starting from specified \p Entry.
+  /// It puts 'root DIE' into the worklist.
+  void collectRootsToKeep(CompileUnit &CU, const DWARFDebugInfoEntry *Entry);
+
+  /// Returns true if specified variable references live code section.
+  bool isLiveVariableEntry(CompileUnit &CU, const DWARFDebugInfoEntry *Entry);
+
+  /// Returns true if specified subprogram references live code section.
+  bool isLiveSubprogramEntry(CompileUnit &CU, const DWARFDebugInfoEntry *Entry);
+
+  /// Examine worklist and mark all 'root DIE's as kept.
+  bool markLiveRootsAsKept();
+
+  /// Mark whole DIE tree as kept recursively.
+  bool markDIEEntryAsKeptRec(const RootEntryTy &RootItem, CompileUnit &CU,
+                             const DWARFDebugInfoEntry *Entry);
+
+  /// Check referenced DIEs and add them into the worklist if neccessary.
+  bool maybeAddReferencedRoots(const RootEntryTy &RootItem, CompileUnit &CU,
+                               const DWARFDebugInfoEntry *Entry);
+
+  /// Add 'root DIE' into the worklist.
+  void addItemToWorklist(CompileUnit &CU, const DWARFDebugInfoEntry *Entry);
+
+  /// Set kind of placement(whether it goes into type table, plain dwarf or
+  /// both) for the specified die \p DieIdx.
+  void setDIEPlacementAndTypename(CompileUnit::DIEInfo &Info);
+
+  /// Flag indicating whether liveness information should be examined.
+  bool TrackLiveness = false;
+
+  /// List of CU, Entry pairs which are 'root DIE's.
+  RootEntriesListTy RootEntriesWorkList;
+
+  /// Link context for the analyzed CU.
+  DWARFLinkerImpl::LinkContext &Context;
+};
+
+} // end namespace dwarflinker_parallel
+} // end namespace llvm
+
+#endif // LLVM_LIB_DWARFLINKERPARALLEL_DEPENDENCYTRACKER_H

llvm/lib/DWARFLinkerParallel/DependencyTracker.cpp

+//=== DependencyTracker.cpp -----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "DependencyTracker.h"
+#include "llvm/Support/FormatVariadic.h"
+
+namespace llvm {
+namespace dwarflinker_parallel {
+
+#ifndef NDEBUG
+/// A broken link in the keep chain. By recording both the parent and the child
+/// we can show only broken links for DIEs with multiple children.
+struct BrokenLink {
+  BrokenLink(DWARFDie Parent, DWARFDie Child) : Parent(Parent), Child(Child) {}
+  DWARFDie Parent;
+  DWARFDie Child;
+};
+
+/// Verify the keep chain by looking for DIEs that are kept but who's parent
+/// isn't.
+void DependencyTracker::verifyKeepChain(CompileUnit &CU) {
+  SmallVector<DWARFDie> Worklist;
+  Worklist.push_back(CU.getOrigUnit().getUnitDIE());
+
+  // List of broken links.
+  SmallVector<BrokenLink> BrokenLinks;
+
+  while (!Worklist.empty()) {
+    const DWARFDie Current = Worklist.back();
+    Worklist.pop_back();
+
+    if (!Current.isValid())
+      continue;
+
+    const bool CurrentDieIsKept = CU.getDIEInfo(Current).getKeep() ||
+                                  CU.getDIEInfo(Current).getKeepChildren();
+
+    for (DWARFDie Child : reverse(Current.children())) {
+      Worklist.push_back(Child);
+
+      const bool ChildDieIsKept = CU.getDIEInfo(Child).getKeep() ||
+                                  CU.getDIEInfo(Child).getKeepChildren();
+      if (!CurrentDieIsKept && ChildDieIsKept)
+        BrokenLinks.emplace_back(Current, Child);
+    }
+  }
+
+  if (!BrokenLinks.empty()) {
+    for (BrokenLink Link : BrokenLinks) {
+      WithColor::error() << formatv(
+          "Found invalid link in keep chain between {0:x} and {1:x}\n",
+          Link.Parent.getOffset(), Link.Child.getOffset());
+
+      errs() << "Parent:";
+      Link.Parent.dump(errs(), 0, {});
+      CU.getDIEInfo(Link.Parent).dump();
+
+      errs() << "Child:";
+      Link.Child.dump(errs(), 2, {});
+      CU.getDIEInfo(Link.Child).dump();
+    }
+    report_fatal_error("invalid keep chain");
+  }
+}
+#endif
+
+bool DependencyTracker::resolveDependenciesAndMarkLiveness(CompileUnit &CU) {
+  // We do not track liveness inside Clang modules. We also do not track
+  // liveness if UpdateIndexTablesOnly is requested.
+  TrackLiveness = !(CU.isClangModule() ||
+                    CU.getGlobalData().getOptions().UpdateIndexTablesOnly);
+  RootEntriesWorkList.clear();
+
+  // Search for live root DIEs.
+  collectRootsToKeep(CU, CU.getDebugInfoEntry(0));
+
+  // Mark live DIEs as kept.
+  return markLiveRootsAsKept();
+}
+
+void DependencyTracker::collectRootsToKeep(CompileUnit &CU,
+                                           const DWARFDebugInfoEntry *Entry) {
+  if (!TrackLiveness) {
+    addItemToWorklist(CU, Entry);
+    return;
+  }
+
+  switch (Entry->getTag()) {
+  case dwarf::DW_TAG_subprogram:
+  case dwarf::DW_TAG_label:
+    if (isLiveSubprogramEntry(CU, Entry)) {
+      addItemToWorklist(CU, Entry);
+      break;
+    }
+    [[fallthrough]];
+  case dwarf::DW_TAG_compile_unit:
+  case dwarf::DW_TAG_namespace:
+  case dwarf::DW_TAG_module:
+  case dwarf::DW_TAG_lexical_block: {
+    for (const DWARFDebugInfoEntry *CurChild = CU.getFirstChildEntry(Entry);
+         CurChild && CurChild->getAbbreviationDeclarationPtr();
+         CurChild = CU.getSiblingEntry(CurChild))
+      collectRootsToKeep(CU, CurChild);
+  } break;
+  case dwarf::DW_TAG_constant:
+  case dwarf::DW_TAG_variable: {
+    if (isLiveVariableEntry(CU, Entry))
+      addItemToWorklist(CU, Entry);
+  } break;
+  case dwarf::DW_TAG_base_type: {
+    addItemToWorklist(CU, Entry);
+  } break;
+  case dwarf::DW_TAG_imported_module:
+  case dwarf::DW_TAG_imported_declaration:
+  case dwarf::DW_TAG_imported_unit: {
+    addItemToWorklist(CU, Entry);
+  } break;
+  default:
+    // Nothing to do.
+    break;
+  }
+}
+
+bool DependencyTracker::markLiveRootsAsKept() {
+  bool Res = true;
+
+  while (!RootEntriesWorkList.empty()) {
+    RootEntryTy CurrentItem = RootEntriesWorkList.pop_back_val();
+
+    if (!markDIEEntryAsKeptRec(CurrentItem, CurrentItem.CU,
+                               CurrentItem.RootEntry))
+      Res = false;
+  }
+
+  return Res;
+}
+
+bool DependencyTracker::markDIEEntryAsKeptRec(
+    const RootEntryTy &RootItem, CompileUnit &CU,
+    const DWARFDebugInfoEntry *Entry) {
+  if (Entry->getAbbreviationDeclarationPtr() == nullptr)
+    return true;
+
+  CompileUnit::DIEInfo &Info = CU.getDIEInfo(Entry);
+
+  if (Info.getKeep())
+    return true;
+
+  // Mark parents as 'KeepChildren'.
+  std::optional<uint32_t> ParentIdx = Entry->getParentIdx();
+  while (ParentIdx) {
+    const DWARFDebugInfoEntry *ParentEntry = CU.getDebugInfoEntry(*ParentIdx);
+    CompileUnit::DIEInfo &ParentInfo = CU.getDIEInfo(*ParentIdx);
+    if (ParentInfo.getKeepChildren())
+      break;
+    ParentInfo.setKeepChildren();
+    ParentIdx = ParentEntry->getParentIdx();
+  }
+
+  // Mark current DIE as kept.
+  Info.setKeep();
+  setDIEPlacementAndTypename(Info);
+
+  // Set liveness information.
+  switch (Entry->getTag()) {
+  case dwarf::DW_TAG_constant:
+  case dwarf::DW_TAG_variable: {
+    isLiveVariableEntry(CU, Entry);
+  } break;
+  case dwarf::DW_TAG_subprogram:
+  case dwarf::DW_TAG_label: {
+    isLiveSubprogramEntry(CU, Entry);
+  } break;
+  default:
+    // Nothing to do.
+    break;
+  }
+
+  // Analyse referenced DIEs.
+  bool Res = true;
+  if (!maybeAddReferencedRoots(RootItem, CU, Entry))
+    Res = false;
+
+  // Navigate children.
+  for (const DWARFDebugInfoEntry *CurChild = CU.getFirstChildEntry(Entry);
+       CurChild && CurChild->getAbbreviationDeclarationPtr();
+       CurChild = CU.getSiblingEntry(CurChild)) {
+    if (!markDIEEntryAsKeptRec(RootItem, CU, CurChild))
+      Res = false;
+  }
+
+  return Res;
+}
+
+bool DependencyTracker::maybeAddReferencedRoots(
+    const RootEntryTy &RootItem, CompileUnit &CU,
+    const DWARFDebugInfoEntry *Entry) {
+  const auto *Abbrev = Entry->getAbbreviationDeclarationPtr();
+  if (Abbrev == nullptr)
+    return true;
+
+  DWARFUnit &Unit = CU.getOrigUnit();
+  DWARFDataExtractor Data = Unit.getDebugInfoExtractor();
+  uint64_t Offset = Entry->getOffset() + getULEB128Size(Abbrev->getCode());
+
+  // For each DIE attribute...
+  for (const auto &AttrSpec : Abbrev->attributes()) {
+    DWARFFormValue Val(AttrSpec.Form);
+    if (!Val.isFormClass(DWARFFormValue::FC_Reference) ||
+        AttrSpec.Attr == dwarf::DW_AT_sibling) {
+      DWARFFormValue::skipValue(AttrSpec.Form, Data, &Offset,
+                                Unit.getFormParams());
+      continue;
+    }
+    Val.extractValue(Data, &Offset, Unit.getFormParams(), &Unit);
+
+    // Resolve reference.
+    std::optional<std::pair<CompileUnit *, uint32_t>> RefDie =
+        CU.resolveDIEReference(Val);
+    if (!RefDie) {
+      CU.warn("cann't find referenced DIE", Entry);
+      continue;
+    }
+
+    if (CU.getUniqueID() == RefDie->first->getUniqueID()) {
+      // Check if referenced DIE entry is already kept.
+      if (RefDie->first->getDIEInfo(RefDie->second).getKeep())
+        continue;
+
+      // If referenced DIE is inside current compilation unit.
+      const DWARFDebugInfoEntry *RefEntry =
+          RefDie->first->getDebugInfoEntry(RefDie->second);
+
+      if (RootItem.RootEntry->getTag() == dwarf::DW_TAG_compile_unit)
+        addItemToWorklist(*RefDie->first, RefEntry);
+      else {
+        uint64_t RootStartOffset = RootItem.RootEntry->getOffset();
+        uint64_t RootEndOffset;
+        if (std::optional<uint32_t> SiblingIdx =
+                RootItem.RootEntry->getSiblingIdx()) {
+          RootEndOffset =
+              RootItem.CU.getDebugInfoEntry(*SiblingIdx)->getOffset();
+        } else {
+          RootEndOffset = RootItem.CU.getOrigUnit().getNextUnitOffset();
+        }
+
+        // Do not put item in work list if it is an ancestor of RootItem.
+        // (since we will visit and mark it as kept during normal traversing of
+        // RootItem children)
+        if (RootStartOffset > RefEntry->getOffset() ||
+            RefEntry->getOffset() >= RootEndOffset)
+          addItemToWorklist(*RefDie->first, RefEntry);
+      }
+    } else if (Context.InterCUProcessingStarted && RefDie->second != 0) {
+      // If referenced DIE is in other compilation unit and
+      // it is safe to navigate other units DIEs.
+      addItemToWorklist(*RefDie->first,
+                        RefDie->first->getDebugInfoEntry(RefDie->second));
+    } else {
+      // Delay resolving reference.
+      RefDie->first->setInterconnectedCU();
+      CU.setInterconnectedCU();
+      Context.HasNewInterconnectedCUs = true;
+      return false;
+    }
+  }
+
+  return true;
+}
+
+// Returns true if the specified DIE type allows removing children.
+static bool childrenCanBeRemoved(uint32_t Tag) {
+  switch (Tag) {
+  default:
+    return true;
+  case dwarf::DW_TAG_class_type:
+  case dwarf::DW_TAG_common_block:
+  case dwarf::DW_TAG_lexical_block:
+  case dwarf::DW_TAG_structure_type:
+  case dwarf::DW_TAG_subprogram:
+  case dwarf::DW_TAG_subroutine_type:
+  case dwarf::DW_TAG_union_type:
+  case dwarf::DW_TAG_array_type:
+    return false;
+  }
+  llvm_unreachable("Invalid Tag");
+}
+
+void DependencyTracker::addItemToWorklist(CompileUnit &CU,
+                                          const DWARFDebugInfoEntry *Entry) {
+  if (Entry->getAbbreviationDeclarationPtr() == nullptr)
+    return;
+
+  const DWARFDebugInfoEntry *EntryToAdd = Entry;
+
+  // If parent does not allow children removing then use that parent as a root
+  // DIE.
+  std::optional<uint32_t> ParentIdx = Entry->getParentIdx();
+  while (ParentIdx) {
+    const DWARFDebugInfoEntry *ParentEntry = CU.getDebugInfoEntry(*ParentIdx);
+    if (childrenCanBeRemoved(ParentEntry->getTag()))
+      break;
+    EntryToAdd = ParentEntry;
+    ParentIdx = ParentEntry->getParentIdx();
+  }
+
+  // Check if the DIE entry is already kept.
+  if (CU.getDIEInfo(EntryToAdd).getKeep())
+    return;
+
+  RootEntriesWorkList.emplace_back(CU, EntryToAdd);
+}
+
+bool DependencyTracker::isLiveVariableEntry(CompileUnit &CU,
+                                            const DWARFDebugInfoEntry *Entry) {
+  DWARFDie DIE = CU.getDIE(Entry);
+  CompileUnit::DIEInfo &Info = CU.getDIEInfo(DIE);
+
+  if (TrackLiveness) {
+    const auto *Abbrev = DIE.getAbbreviationDeclarationPtr();
+
+    // Global variables with constant value can always be kept.
+    if (!Info.getIsInFunctionScope() &&
+        Abbrev->findAttributeIndex(dwarf::DW_AT_const_value))
+      return true;
+
+    // See if there is a relocation to a valid debug map entry inside this
+    // variable's location. The order is important here. We want to always check
+    // if the variable has a location expression address.
+    // However, we don't want a static variable in a function to force us to
+    // keep the enclosing function, unless requested explicitly.
+    std::pair<bool, std::optional<int64_t>> LocExprAddrAndRelocAdjustment =
+        CU.getContaingFile().Addresses->getVariableRelocAdjustment(DIE);
+
+    if (!LocExprAddrAndRelocAdjustment.second)
+      return false;
+
+    if ((Info.getIsInFunctionScope()) &&
+        !LLVM_UNLIKELY(CU.getGlobalData().getOptions().KeepFunctionForStatic))
+      return false;
+  }
+
+  if (CU.getGlobalData().getOptions().Verbose) {
+    outs() << "Keeping variable DIE:";
+    DIDumpOptions DumpOpts;
+    DumpOpts.ChildRecurseDepth = 0;
+    DumpOpts.Verbose = CU.getGlobalData().getOptions().Verbose;
+    DIE.dump(outs(), 8 /* Indent */, DumpOpts);
+  }
+
+  return true;
+}
+
+bool DependencyTracker::isLiveSubprogramEntry(
+    CompileUnit &CU, const DWARFDebugInfoEntry *Entry) {
+  DWARFDie DIE = CU.getDIE(Entry);
+
+  std::optional<uint64_t> LowPc;
+  std::optional<uint64_t> HighPc;
+  std::optional<int64_t> RelocAdjustment;
+
+  if (TrackLiveness) {
+    LowPc = dwarf::toAddress(DIE.find(dwarf::DW_AT_low_pc));
+    if (!LowPc)
+      return false;
+
+    if (DIE.getTag() == dwarf::DW_TAG_subprogram) {
+      // Validate subprogram address range.
+
+      HighPc = DIE.getHighPC(*LowPc);
+      if (!HighPc) {
+        CU.warn("function without high_pc. Range will be discarded.", &DIE);
+        return false;
+      }
+
+      if (*LowPc > *HighPc) {
+        CU.warn("low_pc greater than high_pc. Range will be discarded.", &DIE);
+        return false;
+      }
+    } else if (DIE.getTag() == dwarf::DW_TAG_variable) {
+      // FIXME: dsymutil-classic compat. dsymutil-classic doesn't consider
+      // labels that don't fall into the CU's aranges. This is wrong IMO. Debug
+      // info generation bugs aside, this is really wrong in the case of labels,
+      // where a label marking the end of a function will have a PC == CU's
+      // high_pc.
+      if (dwarf::toAddress(
+              CU.getOrigUnit().getUnitDIE().find(dwarf::DW_AT_high_pc))
+              .value_or(UINT64_MAX) <= LowPc)
+        return false;
+
+      if (!CU.hasLabelAt(*LowPc))
+        CU.addLabelLowPc(*LowPc, *RelocAdjustment);
+    }
+
+    RelocAdjustment =
+        CU.getContaingFile().Addresses->getSubprogramRelocAdjustment(DIE);
+    if (!RelocAdjustment)
+      return false;
+  }
+
+  if (CU.getGlobalData().getOptions().Verbose) {
+    outs() << "Keeping subprogram DIE:";
+    DIDumpOptions DumpOpts;
+    DumpOpts.ChildRecurseDepth = 0;
+    DumpOpts.Verbose = CU.getGlobalData().getOptions().Verbose;
+    DIE.dump(outs(), 8 /* Indent */, DumpOpts);
+  }
+
+  if (!TrackLiveness || DIE.getTag() == dwarf::DW_TAG_label)
+    return true;
+
+  CU.addFunctionRange(*LowPc, *HighPc, *RelocAdjustment);
+  return true;
+}
+
+void DependencyTracker::setDIEPlacementAndTypename(CompileUnit::DIEInfo &Info) {
+  Info.setPlacement(CompileUnit::PlainDwarf);
+}
+
+} // end of namespace dwarflinker_parallel
+} // namespace llvm

llvm/lib/DWARFLinkerParallel/OutputSections.h

 //===- OutputSections.h -----------------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIB_DWARFLINKERPARALLEL_OUTPUTSECTIONS_H
 #define LLVM_LIB_DWARFLINKERPARALLEL_OUTPUTSECTIONS_H
 
+#include "ArrayList.h"
+#include "StringEntryToDwarfStringPoolEntryMap.h"
+#include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/BinaryFormat/Dwarf.h"
+#include "llvm/CodeGen/DwarfStringPoolEntry.h"
+#include "llvm/DWARFLinkerParallel/StringPool.h"
+#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
+#include "llvm/DebugInfo/DWARF/DWARFObject.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/Endian.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/LEB128.h"
+#include "llvm/Support/MemoryBufferRef.h"
+#include "llvm/Support/raw_ostream.h"
 #include <array>
 #include <cstdint>
 
 namespace llvm {
 namespace dwarflinker_parallel {
 
-/// This class keeps offsets to the debug sections. Any object which is
-/// supposed to be emitted into the debug section should use this class to
-/// track debug sections offsets.
-class OutputSections {
-public:
-  /// List of tracked debug sections.
-  enum class DebugSectionKind : uint8_t {
-    DebugInfo = 0,
-    DebugLine,
-    DebugFrame,
-    DebugRange,
-    DebugRngLists,
-    DebugLoc,
-    DebugLocLists,
-    DebugARanges,
-    DebugAbbrev,
-    DebugMacinfo,
-    DebugMacro,
-  };
-  constexpr static size_t SectionKindsNum = 11;
+/// List of tracked debug tables.
+  DebugAddr,
+  NumberOfEnumEntries // must be last
+};
+constexpr static size_t SectionKindsNum =
+    static_cast<size_t>(DebugSectionKind::NumberOfEnumEntries);
+
+/// Recognise the table name and match it with the DebugSectionKind.
+std::optional<DebugSectionKind> parseDebugTableName(StringRef Name);
+
+/// Return the name of the section.
+const StringLiteral &getSectionName(DebugSectionKind SectionKind);
+
+/// There are fields(sizes, offsets) which should be updated after
+/// sections are generated. To remember offsets and related data
+/// the descendants of SectionPatch structure should be used.
+
+struct SectionPatch {
+  uint64_t PatchOffset = 0;
+};
+
+/// This structure is used to update strings offsets into .debug_str.
+struct DebugStrPatch : SectionPatch {
+  StringEntry *String = nullptr;
+};
+
+/// This structure is used to update strings offsets into .debug_line_str.
+struct DebugLineStrPatch : SectionPatch {
+  StringEntry *String = nullptr;
+};
+
+/// This structure is used to update range list offset into
+/// .debug_ranges/.debug_rnglists.
+struct DebugRangePatch : SectionPatch {
+  /// Indicates patch which points to immediate compile unit's attribute.
+  bool IsCompileUnitRanges = false;
 
-  /// Recognise the section name and match it with the DebugSectionKind.
-  static std::optional<DebugSectionKind> parseDebugSectionName(StringRef Name);
+/// This structure is used to update location list offset into
+/// .debug_loc/.debug_loclists.
+struct DebugLocPatch : SectionPatch {
+  int64_t AddrAdjustmentValue = 0;
+};
+
+/// This structure is used to update offset with start of another section.
+struct SectionDescriptor;
+struct DebugOffsetPatch : SectionPatch {
+  DebugOffsetPatch(uint64_t PatchOffset, SectionDescriptor *SectionPtr,
+                   bool AddLocalValue = false)
+      : SectionPatch({PatchOffset}), SectionPtr(SectionPtr, AddLocalValue) {}
+
+  PointerIntPair<SectionDescriptor *, 1> SectionPtr;
+};
+
+/// This structure is used to update reference to the DIE.
+struct DebugDieRefPatch : SectionPatch {
+  DebugDieRefPatch(uint64_t PatchOffset, CompileUnit *SrcCU, CompileUnit *RefCU,
+                   uint32_t RefIdx);
+
+  PointerIntPair<CompileUnit *, 1> RefCU;
+  uint64_t RefDieIdxOrClonedOffset;
+};
+
+/// This structure is used to update reference to the DIE of ULEB128 form.
+struct DebugULEB128DieRefPatch : SectionPatch {
+  DebugULEB128DieRefPatch(uint64_t PatchOffset, CompileUnit *SrcCU,
+                          CompileUnit *RefCU, uint32_t RefIdx);
+
+  PointerIntPair<CompileUnit *, 1> RefCU;
+  uint64_t RefDieIdxOrClonedOffset;
+};
+
+/// Type for section data.
+using OutSectionDataTy = SmallString<0>;
+
+/// Type for list of pointers to patches offsets.
+using OffsetsPtrVector = SmallVector<uint64_t *>;
+
+class OutputSections;
+
+/// This structure is used to keep data of the concrete section.
+/// Like data bits, list of patches, format.
+struct SectionDescriptor {
+  friend OutputSections;
+
+  SectionDescriptor() : OS(Contents) {}
+
+  /// Erase whole section contents(data bits, list of patches, format).
+  void erase();
 
   /// When objects(f.e. compile units) are glued into the single file,
   /// the debug sections corresponding to the concrete object are assigned
-  /// with offsets inside the whole file. This method returns offset
-  /// to the \p SectionKind debug section, corresponding to this object.
-  uint64_t getStartOffset(DebugSectionKind SectionKind) const {
-    return Offsets[static_cast<
+  /// with offsets inside the whole file. This field keeps offset
+  /// to the debug section, corresponding to this object.
+  uint64_t StartOffset;
+
+  /// Stream which stores data to the Contents.
+  raw_svector_ostream OS;
+
+  /// Section patches.
+#define ADD_PATCHES_LIST(T)                                                    \
+  T &notePatch(const T &Patch) { return List##T.noteItem(Patch); }             \
+  ArrayList<T> List##T;
+
+  ADD_PATCHES_LIST(DebugStrPatch)
+  ADD_PATCHES_LIST(DebugLineStrPatch)
+  ADD_PATCHES_LIST(DebugRangePatch)
+  ADD_PATCHES_LIST(DebugLocPatch)
+  ADD_PATCHES_LIST(DebugDieRefPatch)
+  ADD_PATCHES_LIST(DebugULEB128DieRefPatch)
+  ADD_PATCHES_LIST(DebugOffsetPatch)
+
+  /// Offsets to some fields are not known at the moment of noting patch.
+  /// In that case we remember pointers to patch offset to update them later.
+  template <typename T>
+  void notePatchWithOffsetUpdate(const T &Patch,
+                                 OffsetsPtrVector &PatchesOffsetsList) {
+    PatchesOffsetsList.emplace_back(&notePatch(Patch).PatchOffset);
+  }
+
+  /// Some sections are emitted using AsmPrinter. In that case "Contents"
+  /// member of SectionDescriptor contains elf file. This method searches
+  /// for section data inside elf file and remember offset to it.
+  void setSizesForSectionCreatedByAsmPrinter();
+
+  /// Returns section content.
+  StringRef getContents() {
+    if (SectionOffsetInsideAsmPrinterOutputStart == 0)
+      return StringRef(Contents.data(), Contents.size());
+
+    return Contents.slice(SectionOffsetInsideAsmPrinterOutputStart,
+                          SectionOffsetInsideAsmPrinterOutputEnd);
+  }
+
+  /// Emit unit length into the current section contents.
+  void emitUnitLength(uint64_t Length) {
+    maybeEmitDwarf64Mark();
+    emitIntVal(Length, getFormParams().getDwarfOffsetByteSize());
+  }
+
+  /// Emit DWARF64 mark into the current section contents.
+  void maybeEmitDwarf64Mark() {
+    if (getFormParams().Format != dwarf::DWARF64)
+      return;
+    emitIntVal(dwarf::DW_LENGTH_DWARF64, 4);
+  }
+
+  /// Emit specified offset value into the current section contents.
+  void emitOffset(uint64_t Val) {
+    emitIntVal(Val, getFormParams().getDwarfOffsetByteSize());
+  }
+
+  /// Emit specified integer value into the current section contents.
+  void emitIntVal(uint64_t Val, unsigned Size);
+
+  /// Emit specified string value into the current section contents.
+  void emitString(dwarf::Form StringForm, const char *StringVal);
+
+  /// Emit specified inplace string value into the current section contents.
+  void emitInplaceString(StringRef String) {
+    OS << String;
+    emitIntVal(0, 1);
+  }
+
+  /// Emit string placeholder into the current section contents.
+  void emitStringPlaceholder() {
+    // emit bad offset which should be updated later.
+    emitOffset(0xBADDEF);
+  }
+
+  /// Write specified \p Value of \p AttrForm to the \p PatchOffset.
+  void apply(uint64_t PatchOffset, dwarf::Form AttrForm, uint64_t Val);
+
+  /// Returns section kind.
+  DebugSectionKind getKind() { return SectionKind; }
+
+  /// Returns section name.
+  const StringLiteral &getName() const { return getSectionName(SectionKind); }
+
+  /// Returns endianess used by section.
+  support::endianness getEndianess() const { return Endianess; };
+
+  /// Returns FormParams used by section.
+  dwarf::FormParams getFormParams() const { return Format; }
+
+  /// Returns integer value of \p Size located by specified \p PatchOffset.
+  uint64_t getIntVal(uint64_t PatchOffset, unsigned Size);
+
+  void setGlobalData(LinkingGlobalData *GlobalData) {
+    this->GlobalData = GlobalData;
+    ListDebugStrPatch.setAllocator(&GlobalData->getAllocator());
+    ListDebugLineStrPatch.setAllocator(&GlobalData->getAllocator());
+    ListDebugRangePatch.setAllocator(&GlobalData->getAllocator());
+    ListDebugLocPatch.setAllocator(&GlobalData->getAllocator());
+    ListDebugDieRefPatch.setAllocator(&GlobalData->getAllocator());
+    ListDebugULEB128DieRefPatch.setAllocator(&GlobalData->getAllocator());
+    ListDebugOffsetPatch.setAllocator(&GlobalData->getAllocator());
+  }
+
+protected:
+  /// Writes integer value \p Val of \p Size by specified \p PatchOffset.
+  void applyIntVal(uint64_t PatchOffset, uint64_t Val, unsigned Size);
+
+  /// Writes integer value \p Val of ULEB128 format by specified \p PatchOffset.
+  void applyULEB128(uint64_t PatchOffset, uint64_t Val);
+
+  /// Writes integer value \p Val of SLEB128 format by specified \p PatchOffset.
+  void applySLEB128(uint64_t PatchOffset, uint64_t Val);
+
+  /// Sets output format.
+  void setOutputFormat(dwarf::FormParams Format,
+                       support::endianness Endianess) {
+    this->Format = Format;
+    this->Endianess = Endianess;
+  }
+
+  LinkingGlobalData *GlobalData = nullptr;
+
+  /// The section kind.
+  DebugSectionKind SectionKind;
+
+  /// Section data bits.
+  OutSectionDataTy Contents;
+
+  /// Some sections are generated using AsmPrinter. The real section data
+  /// located inside elf file in that case. Following fields points to the
+  /// real section content inside elf file.
+  size_t SectionOffsetInsideAsmPrinterOutputStart = 0;
+  size_t SectionOffsetInsideAsmPrinterOutputEnd = 0;
+
+  /// Output format.
+  dwarf::FormParams Format = {4, 4, dwarf::DWARF32};
+  support::endianness Endianess = support::endianness::little;
+};
+
+/// This class keeps contents and offsets to the debug sections. Any objects
+/// which is supposed to be emitted into the debug sections should use this
+/// class to track debug sections offsets and keep sections data.
+class OutputSections {
+public:
+  OutputSections() {
+    for (size_t Idx = 0; Idx < SectionKindsNum; ++Idx)
+      SectionDescriptors[Idx].SectionKind = static_cast<DebugSectionKind>(Idx);
+  }
+
+  /// Sets output format for all keeping sections.
+  void setOutputFormat(DWARFUnit &OriginalUnit) {
+    setOutputFormat(OriginalUnit.getFormParams(),
+                    OriginalUnit.isLittleEndian() ? support::endianness::little
+                                                  : support::endianness::big);
+  }
+
+  /// Sets output format for all keeping sections.
+  void setOutputFormat(dwarf::FormParams Format,
+                       support::endianness Endianess) {
+    this->Format = Format;
+    this->Endianess = Endianess;
+
+    for (size_t Idx = 0; Idx < SectionKindsNum; ++Idx) {
+      SectionDescriptors[Idx].Format = Format;
+      SectionDescriptors[Idx].Endianess = Endianess;
+    }
+  }
+
+  void setGlobalData(LinkingGlobalData *GlobalData) {
+    this->GlobalData = GlobalData;
+    for (size_t Idx = 0; Idx < SectionKindsNum; ++Idx)
+      SectionDescriptors[Idx].setGlobalData(GlobalData);
+  }
+
+  /// Returns descriptor for the specified section of \p SectionKind.
+  const SectionDescriptor &
+  getSectionDescriptor(DebugSectionKind SectionKind) const {
+    return SectionDescriptors[static_cast<
+        typename std::underlying_type<DebugSectionKind>::type>(SectionKind)];
+  }
+
+  /// Returns descriptor for the specified section of \p SectionKind.
+  SectionDescriptor &getSectionDescriptor(DebugSectionKind SectionKind) {
+    return SectionDescriptors[static_cast<
         typename std::underlying_type<DebugSectionKind>::type>(SectionKind)];
   }
 
-  /// Set offset to the start of specified \p SectionKind debug section,
-  /// corresponding to this object.
-  void setStartOffset(DebugSectionKind SectionKind, uint64_t Offset) {
-    Offsets[static_cast<typename std::underlying_type<DebugSectionKind>::type>(
-        SectionKind)] = Offset;
+  /// Erases data of all sections.
+  void eraseSections() {
+    for (SectionDescriptor &CurSection : SectionDescriptors)
+      CurSection.erase();
+  }
+
+  /// Enumerate all sections and call \p Handler for each.
+  void forEach(function_ref<void(SectionDescriptor &)> Handler) {
+    for (size_t Idx = 0; Idx < SectionKindsNum; ++Idx)
+      Handler(SectionDescriptors[Idx]);
+  }
+
+  /// Enumerate all sections, for each section set current offset
+  /// (kept by \p SectionSizesAccumulator), update current offset with section
+  /// length.
+  void assignSectionsOffsetAndAccumulateSize(
+      std::array<uint64_t, SectionKindsNum> &SectionSizesAccumulator) {
+    for (size_t Idx = 0; Idx < SectionKindsNum; ++Idx) {
+      SectionDescriptor &Section = SectionDescriptors[Idx];
+      Section.StartOffset = SectionSizesAccumulator[Idx];
+      SectionSizesAccumulator[Idx] += Section.getContents().size();
     }
+  }
+
+  /// Enumerate all sections, for each section apply all section patches.
+  void applyPatches(SectionDescriptor &Section,
+                    StringEntryToDwarfStringPoolEntryMap &DebugStrStrings,
+                    StringEntryToDwarfStringPoolEntryMap &DebugLineStrStrings);
+
+  /// Endiannes for the sections.
+  support::endianness getEndianness() const { return Endianess; }
+
+  /// Return DWARF version.
+  uint16_t getVersion() const { return Format.Version; }
+
+  /// Return size of header of debug_info table.
+  uint16_t getHeaderSize() const { return Format.Version >= 5 ? 12 : 11; }
+
+  /// Return size of address.
+  const dwarf::FormParams &getFormParams() const { return Format; }
 
 protected:
-  /// Offsets to the debug sections composing this object.
-  std::array<uint64_t, SectionKindsNum> Offsets = {0};
+  LinkingGlobalData *GlobalData = nullptr;
+
+  /// Format for sections.
+  dwarf::FormParams Format = {4, 4, dwarf::DWARF32};
+
+  /// Endiannes for sections.
+  support::endianness Endianess = support::endianness::little;
+
+  /// All keeping sections.
+  std::array<SectionDescriptor, SectionKindsNum> SectionDescriptors;
 };
 
 } // end of namespace dwarflinker_parallel
 } // end namespace llvm
 
 #endif // LLVM_LIB_DWARFLINKERPARALLEL_OUTPUTSECTIONS_H

llvm/lib/DWARFLinkerParallel/OutputSections.cpp

 //=== OutputSections.cpp --------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "OutputSections.h"
+#include "DWARFLinkerCompileUnit.h"
 #include "llvm/ADT/StringSwitch.h"
 
 namespace llvm {
 namespace dwarflinker_parallel {
 
-std::optional<OutputSections::DebugSectionKind>
-OutputSections::parseDebugSectionName(llvm::StringRef SecName) {
-  return llvm::StringSwitch<std::optional<OutputSections::DebugSectionKind>>(
-             SecName)
-      .Case("debug_info", DebugSectionKind::DebugInfo)
-      .Case("debug_line", DebugSectionKind::DebugLine)
-      .Case("debug_frame", DebugSectionKind::DebugFrame)
-      .Case("debug_ranges", DebugSectionKind::DebugRange)
-      .Case("debug_rnglists", DebugSectionKind::DebugRngLists)
-      .Case("debug_loc", DebugSectionKind::DebugLoc)
-      .Case("debug_loclists", DebugSectionKind::DebugLocLists)
-      .Case("debug_aranges", DebugSectionKind::DebugARanges)
-      .Case("debug_abbrev", DebugSectionKind::DebugAbbrev)
-      .Case("debug_macinfo", DebugSectionKind::DebugMacinfo)
-      .Case("debug_macro", DebugSectionKind::DebugMacro)
+static constexpr StringLiteral SectionNames[SectionKindsNum] = {
+    "debug_info",     "debug_line",    "debug_frame",    "debug_ranges",
+    "debug_rnglists", "debug_loc",     "debug_loclists", "debug_aranges",
+    "debug_abbrev",   "debug_macinfo", "debug_macro",    "debug_addr",
+};
+
+const StringLiteral &getSectionName(DebugSectionKind SectionKind) {
+  return SectionNames[static_cast<uint8_t>(SectionKind)];
+}
+
+std::optional<DebugSectionKind> parseDebugTableName(llvm::StringRef SecName) {
+  return llvm::StringSwitch<std::optional<DebugSectionKind>>(
+             SecName.substr(SecName.find_first_not_of("._")))
+      .Case(getSectionName(DebugSectionKind::DebugInfo),
+            DebugSectionKind::DebugInfo)
+      .Case(getSectionName(DebugSectionKind::DebugLine),
+            DebugSectionKind::DebugLine)
+      .Case(getSectionName(DebugSectionKind::DebugFrame),
+            DebugSectionKind::DebugFrame)
+      .Case(getSectionName(DebugSectionKind::DebugRange),
+            DebugSectionKind::DebugRange)
+      .Case(getSectionName(DebugSectionKind::DebugRngLists),
+            DebugSectionKind::DebugRngLists)
+      .Case(getSectionName(DebugSectionKind::DebugLoc),
+            DebugSectionKind::DebugLoc)
+      .Case(getSectionName(DebugSectionKind::DebugLocLists),
+            DebugSectionKind::DebugLocLists)
+      .Case(getSectionName(DebugSectionKind::DebugARanges),
+            DebugSectionKind::DebugARanges)
+      .Case(getSectionName(DebugSectionKind::DebugAbbrev),
+            DebugSectionKind::DebugAbbrev)
+      .Case(getSectionName(DebugSectionKind::DebugMacinfo),
+            DebugSectionKind::DebugMacinfo)
+      .Case(getSectionName(DebugSectionKind::DebugMacro),
+            DebugSectionKind::DebugMacro)
+      .Case(getSectionName(DebugSectionKind::DebugAddr),
+            DebugSectionKind::DebugAddr)
       .Default(std::nullopt);
 
   return std::nullopt;
 }
 
+DebugDieRefPatch::DebugDieRefPatch(uint64_t PatchOffset, CompileUnit *SrcCU,
+                                   CompileUnit *RefCU, uint32_t RefIdx)
+    : SectionPatch({PatchOffset}),
+      RefCU(RefCU, (SrcCU != nullptr) &&
+                       (SrcCU->getUniqueID() == RefCU->getUniqueID())),
+      RefDieIdxOrClonedOffset(RefIdx) {}
+
+DebugULEB128DieRefPatch::DebugULEB128DieRefPatch(uint64_t PatchOffset,
+                                                 CompileUnit *SrcCU,
+                                                 CompileUnit *RefCU,
+                                                 uint32_t RefIdx)
+    : SectionPatch({PatchOffset}),
+      RefCU(RefCU, SrcCU->getUniqueID() == RefCU->getUniqueID()),
+      RefDieIdxOrClonedOffset(RefIdx) {}
+
+void SectionDescriptor::erase() {
+  StartOffset = 0;
+  Contents = OutSectionDataTy();
+  ListDebugStrPatch.erase();
+  ListDebugLineStrPatch.erase();
+  ListDebugRangePatch.erase();
+  ListDebugLocPatch.erase();
+  ListDebugDieRefPatch.erase();
+  ListDebugULEB128DieRefPatch.erase();
+  ListDebugOffsetPatch.erase();
+}
+
+void SectionDescriptor::setSizesForSectionCreatedByAsmPrinter() {
+  if (Contents.empty())
+    return;
+
+  MemoryBufferRef Mem(Contents, "obj");
+  Expected<std::unique_ptr<object::ObjectFile>> Obj =
+      object::ObjectFile::createObjectFile(Mem);
+  if (!Obj) {
+    consumeError(Obj.takeError());
+    Contents.clear();
+    return;
+  }
+
+  for (const object::SectionRef &Sect : (*Obj).get()->sections()) {
+    Expected<StringRef> SectNameOrErr = Sect.getName();
+    if (!SectNameOrErr) {
+      consumeError(SectNameOrErr.takeError());
+      continue;
+    }
+
+    if (std::optional<DebugSectionKind> SectKind =
+            parseDebugTableName(*SectNameOrErr)) {
+      if (*SectKind == SectionKind) {
+        Expected<StringRef> Data = Sect.getContents();
+        if (!Data) {
+          consumeError(SectNameOrErr.takeError());
+          Contents.clear();
+          return;
+        }
+
+        SectionOffsetInsideAsmPrinterOutputStart =
+            Data->data() - Contents.data();
+        SectionOffsetInsideAsmPrinterOutputEnd =
+            SectionOffsetInsideAsmPrinterOutputStart + Data->size();
+      }
+    }
+  }
+
+  return;
+}
+
+void SectionDescriptor::emitIntVal(uint64_t Val, unsigned Size) {
+  switch (Size) {
+  case 1: {
+    uint8_t ShortVal = static_cast<uint8_t>(Val);
+    OS.write(reinterpret_cast<const char *>(&ShortVal), Size);
+  } break;
+  case 2: {
+    uint16_t ShortVal = static_cast<uint16_t>(Val);
+    ShortVal = support::endian::byte_swap(ShortVal, getEndianess());
+    OS.write(reinterpret_cast<const char *>(&ShortVal), Size);
+  } break;
+  case 4: {
+    uint32_t ShortVal = static_cast<uint32_t>(Val);
+    ShortVal = support::endian::byte_swap(ShortVal, getEndianess());
+    OS.write(reinterpret_cast<const char *>(&ShortVal), Size);
+  } break;
+  case 8: {
+    uint64_t ShortVal = static_cast<uint64_t>(Val);
+    ShortVal = support::endian::byte_swap(ShortVal, getEndianess());
+    OS.write(reinterpret_cast<const char *>(&ShortVal), Size);
+  } break;
+  default:
+    llvm_unreachable("Unsupported integer type size");
+  }
+}
+
+void SectionDescriptor::emitString(dwarf::Form StringForm,
+                                   const char *StringVal) {
+  assert(StringVal != nullptr);
+
+  switch (StringForm) {
+  case dwarf::DW_FORM_string: {
+    emitInplaceString(GlobalData->translateString(StringVal));
+  } break;
+  case dwarf::DW_FORM_strp: {
+    notePatch(DebugStrPatch{
+        {OS.tell()}, GlobalData->getStringPool().insert(StringVal).first});
+    emitStringPlaceholder();
+  } break;
+  case dwarf::DW_FORM_line_strp: {
+    notePatch(DebugLineStrPatch{
+        {OS.tell()}, GlobalData->getStringPool().insert(StringVal).first});
+    emitStringPlaceholder();
+  } break;
+  default:
+    llvm_unreachable("Unsupported string form");
+    break;
+  };
+}
+
+void SectionDescriptor::apply(uint64_t PatchOffset, dwarf::Form AttrForm,
+                              uint64_t Val) {
+  switch (AttrForm) {
+  case dwarf::DW_FORM_strp:
+  case dwarf::DW_FORM_line_strp: {
+    applyIntVal(PatchOffset, Val, Format.getDwarfOffsetByteSize());
+  } break;
+
+  case dwarf::DW_FORM_ref_addr: {
+    applyIntVal(PatchOffset, Val, Format.getRefAddrByteSize());
+  } break;
+  case dwarf::DW_FORM_ref1: {
+    applyIntVal(PatchOffset, Val, 1);
+  } break;
+  case dwarf::DW_FORM_ref2: {
+    applyIntVal(PatchOffset, Val, 2);
+  } break;
+  case dwarf::DW_FORM_ref4: {
+    applyIntVal(PatchOffset, Val, 4);
+  } break;
+  case dwarf::DW_FORM_ref8: {
+    applyIntVal(PatchOffset, Val, 8);
+  } break;
+
+  case dwarf::DW_FORM_data1: {
+    applyIntVal(PatchOffset, Val, 1);
+  } break;
+  case dwarf::DW_FORM_data2: {
+    applyIntVal(PatchOffset, Val, 2);
+  } break;
+  case dwarf::DW_FORM_data4: {
+    applyIntVal(PatchOffset, Val, 4);
+  } break;
+  case dwarf::DW_FORM_data8: {
+    applyIntVal(PatchOffset, Val, 8);
+  } break;
+  case dwarf::DW_FORM_udata: {
+    applyULEB128(PatchOffset, Val);
+  } break;
+  case dwarf::DW_FORM_sdata: {
+    applySLEB128(PatchOffset, Val);
+  } break;
+  case dwarf::DW_FORM_sec_offset: {
+    applyIntVal(PatchOffset, Val, Format.getDwarfOffsetByteSize());
+  } break;
+  case dwarf::DW_FORM_flag: {
+    applyIntVal(PatchOffset, Val, 1);
+  } break;
+
+  default:
+    llvm_unreachable("Unsupported attribute form");
+    break;
+  }
+}
+
+uint64_t SectionDescriptor::getIntVal(uint64_t PatchOffset, unsigned Size) {
+  assert(PatchOffset < getContents().size());
+  switch (Size) {
+  case 1: {
+    return support::endian::read<uint8_t>(
+        const_cast<char *>(getContents().data() + PatchOffset), Endianess);
+  }
+  case 2: {
+    return support::endian::read<uint16_t>(
+        const_cast<char *>(getContents().data() + PatchOffset), Endianess);
+  }
+  case 4: {
+    return support::endian::read<uint32_t>(
+        const_cast<char *>(getContents().data() + PatchOffset), Endianess);
+  }
+  case 8: {
+    return support::endian::read<uint64_t>(
+        const_cast<char *>(getContents().data() + PatchOffset), Endianess);
+  }
+  }
+  llvm_unreachable("Unsupported integer type size");
+  return 0;
+}
+
+void SectionDescriptor::applyIntVal(uint64_t PatchOffset, uint64_t Val,
+                                    unsigned Size) {
+  assert(PatchOffset < getContents().size());
+
+  switch (Size) {
+  case 1: {
+    support::endian::write(
+        const_cast<char *>(getContents().data() + PatchOffset),
+        static_cast<uint8_t>(Val), Endianess);
+  } break;
+  case 2: {
+    support::endian::write(
+        const_cast<char *>(getContents().data() + PatchOffset),
+        static_cast<uint16_t>(Val), Endianess);
+  } break;
+  case 4: {
+    support::endian::write(
+        const_cast<char *>(getContents().data() + PatchOffset),
+        static_cast<uint32_t>(Val), Endianess);
+  } break;
+  case 8: {
+    support::endian::write(
+        const_cast<char *>(getContents().data() + PatchOffset),
+        static_cast<uint64_t>(Val), Endianess);
+  } break;
+  default:
+    llvm_unreachable("Unsupported integer type size");
+  }
+}
+
+void SectionDescriptor::applyULEB128(uint64_t PatchOffset, uint64_t Val) {
+  assert(PatchOffset < getContents().size());
+
+  uint8_t ULEB[16];
+  uint8_t DestSize = Format.getDwarfOffsetByteSize() + 1;
+  uint8_t RealSize = encodeULEB128(Val, ULEB, DestSize);
+
+  memcpy(const_cast<char *>(getContents().data() + PatchOffset), ULEB,
+         RealSize);
+}
+
+/// Writes integer value \p Val of SLEB128 format by specified \p PatchOffset.
+void SectionDescriptor::applySLEB128(uint64_t PatchOffset, uint64_t Val) {
+  assert(PatchOffset < getContents().size());
+
+  uint8_t SLEB[16];
+  uint8_t DestSize = Format.getDwarfOffsetByteSize() + 1;
+  uint8_t RealSize = encodeSLEB128(Val, SLEB, DestSize);
+
+  memcpy(const_cast<char *>(getContents().data() + PatchOffset), SLEB,
+         RealSize);
+}
+
+void OutputSections::applyPatches(
+    SectionDescriptor &Section,
+    StringEntryToDwarfStringPoolEntryMap &DebugStrStrings,
+    StringEntryToDwarfStringPoolEntryMap &DebugLineStrStrings) {
+
+  Section.ListDebugStrPatch.forEach([&](DebugStrPatch &Patch) {
+    DwarfStringPoolEntryWithExtString *Entry =
+        DebugStrStrings.getExistingEntry(Patch.String);
+    assert(Entry != nullptr);
+
+    Section.apply(Patch.PatchOffset, dwarf::DW_FORM_strp, Entry->Offset);
+  });
+
+  Section.ListDebugLineStrPatch.forEach([&](DebugLineStrPatch &Patch) {
+    DwarfStringPoolEntryWithExtString *Entry =
+        DebugLineStrStrings.getExistingEntry(Patch.String);
+    assert(Entry != nullptr);
+
+    Section.apply(Patch.PatchOffset, dwarf::DW_FORM_line_strp, Entry->Offset);
+  });
+
+  SectionDescriptor *RangeSection = nullptr;
+  if (Format.Version >= 5)
+    RangeSection = &getSectionDescriptor(DebugSectionKind::DebugRngLists);
+  else
+    RangeSection = &getSectionDescriptor(DebugSectionKind::DebugRange);
+  Section.ListDebugRangePatch.forEach([&](DebugRangePatch &Patch) {
+    uint64_t FinalValue =
+        Section.getIntVal(Patch.PatchOffset, Format.getDwarfOffsetByteSize());
+    FinalValue += RangeSection->StartOffset;
+
+    Section.apply(Patch.PatchOffset, dwarf::DW_FORM_sec_offset, FinalValue);
+  });
+
+  SectionDescriptor *LocationSection = nullptr;
+  if (Format.Version >= 5)
+    LocationSection = &getSectionDescriptor(DebugSectionKind::DebugLocLists);
+  else
+    LocationSection = &getSectionDescriptor(DebugSectionKind::DebugLoc);
+  Section.ListDebugLocPatch.forEach([&](DebugLocPatch &Patch) {
+    uint64_t FinalValue =
+        Section.getIntVal(Patch.PatchOffset, Format.getDwarfOffsetByteSize());
+    FinalValue += LocationSection->StartOffset;
+
+    Section.apply(Patch.PatchOffset, dwarf::DW_FORM_sec_offset, FinalValue);
+  });
+
+  Section.ListDebugDieRefPatch.forEach([&](DebugDieRefPatch &Patch) {
+    uint64_t FinalOffset = Patch.RefDieIdxOrClonedOffset;
+    dwarf::Form FinalForm = dwarf::DW_FORM_ref4;
+
+    if (!Patch.RefCU.getInt()) {
+      FinalForm = dwarf::DW_FORM_ref_addr;
+      FinalOffset += Patch.RefCU.getPointer()
+                         ->getSectionDescriptor(DebugSectionKind::DebugInfo)
+                         .StartOffset;
+    }
+    Section.apply(Patch.PatchOffset, FinalForm, FinalOffset);
+  });
+
+  Section.ListDebugULEB128DieRefPatch.forEach(
+      [&](DebugULEB128DieRefPatch &Patch) {
+        assert(Patch.RefCU.getInt());
+        Section.apply(Patch.PatchOffset, dwarf::DW_FORM_udata,
+                      Patch.RefDieIdxOrClonedOffset);
+      });
+
+  Section.ListDebugOffsetPatch.forEach([&](DebugOffsetPatch &Patch) {
+    uint64_t FinalValue = Patch.SectionPtr.getPointer()->StartOffset;
+    if (Patch.SectionPtr.getInt())
+      FinalValue +=
+          Section.getIntVal(Patch.PatchOffset, Format.getDwarfOffsetByteSize());
+
+    Section.apply(Patch.PatchOffset, dwarf::DW_FORM_sec_offset, FinalValue);
+  });
+}
+
 } // end of namespace dwarflinker_parallel
 } // end of namespace llvm

llvm/lib/DWARFLinkerParallel/StringEntryToDwarfStringPoolEntryMap.h

+//===- StringEntryToDwarfStringPoolEntryMap.h -------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_DWARFLINKERPARALLEL_STRINGENTRYTODWARFSTRINGPOOLENTRYMAP_H
+#define LLVM_LIB_DWARFLINKERPARALLEL_STRINGENTRYTODWARFSTRINGPOOLENTRYMAP_H
+
+#include "DWARFLinkerGlobalData.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/DWARFLinkerParallel/StringPool.h"
+
+namespace llvm {
+namespace dwarflinker_parallel {
+
+/// This class creates a DwarfStringPoolEntry for the corresponding StringEntry.
+class StringEntryToDwarfStringPoolEntryMap {
+public:
+  StringEntryToDwarfStringPoolEntryMap(LinkingGlobalData &GlobalData)
+      : GlobalData(GlobalData) {}
+  ~StringEntryToDwarfStringPoolEntryMap() {}
+
+  /// Create DwarfStringPoolEntry for specified StringEntry if necessary.
+  /// Initialize DwarfStringPoolEntry with initial values.
+  DwarfStringPoolEntryWithExtString *add(StringEntry *String) {
+    DwarfStringPoolEntriesTy::iterator it = DwarfStringPoolEntries.find(String);
+
+    if (it == DwarfStringPoolEntries.end()) {
+      DwarfStringPoolEntryWithExtString *DataPtr =
+          GlobalData.getAllocator()
+              .Allocate<DwarfStringPoolEntryWithExtString>();
+      DataPtr->String = GlobalData.translateString(String->getKey());
+      DataPtr->Index = DwarfStringPoolEntry::NotIndexed;
+      DataPtr->Offset = 0;
+      DataPtr->Symbol = nullptr;
+      it = DwarfStringPoolEntries.insert(std::make_pair(String, DataPtr)).first;
+    }
+
+    assert(it->second != nullptr);
+    return it->second;
+  }
+
+  /// Returns already existed DwarfStringPoolEntry for the specified
+  /// StringEntry.
+  DwarfStringPoolEntryWithExtString *
+  getExistingEntry(StringEntry *String) const {
+    DwarfStringPoolEntriesTy::const_iterator it =
+        DwarfStringPoolEntries.find(String);
+
+    assert(it != DwarfStringPoolEntries.end());
+    assert(it->second != nullptr);
+    return it->second;
+  }
+
+  /// Erase contents of StringsForEmission.
+  void clear() { DwarfStringPoolEntries.clear(); }
+
+protected:
+  using DwarfStringPoolEntriesTy =
+      DenseMap<StringEntry *, DwarfStringPoolEntryWithExtString *>;
+  DwarfStringPoolEntriesTy DwarfStringPoolEntries;
+
+  LinkingGlobalData &GlobalData;
+};
+
+} // end of namespace dwarflinker_parallel
+} // end namespace llvm
+
+#endif // LLVM_LIB_DWARFLINKERPARALLEL_STRINGENTRYTODWARFSTRINGPOOLENTRYMAP_H

llvm/test/tools/dsymutil/ARM/DWARFLinkerParallel/dwarf5-dwarf4-combination-macho.test

+; This test checks to ensure that if a DWARF v5 and DWARF v4 object file is used to
+; generate a dsym, dsymutil correctly outputs the debug information, by keeping
+; the DWARF v5 and DWARF v4 debug info distinct, and that all the section headers
+; have the correct format.
+
+; 1.o was produced with the source file:
+
+; a.cpp
+; __attribute__((section("1,__text_foo"))) void foo() {}
+;
+; int foo2(int a) {
+;     return a+5;
+; }
+; int main () {
+;     return 1;
+; }
+
+; clang -g -c -O1 a.cpp -Xclang -gdwarf-5 -o 1.o
+
+; 2.o was produced with the following source file:
+
+; b.cpp
+; __attribute__((section("1,__text_foo2"))) void foo2() {}
+;
+; int bar(int x) {
+;     int y = x + 2;
+;     return y;
+; }
+
+; clang -g -c -O1 b.cpp -gdwarf-4 -o 2.o
+
+
+RUN: rm -rf %t.dir && mkdir -p %t.dir
+RUN: dsymutil --linker llvm -y %p/../dummy-debug-map-amr64.map \
+RUN:   -oso-prepend-path=%p/../../Inputs/DWARF5-DWARF4-combination \
+RUN:   -o %t.dir/dwarf5-dwarf4-combination-macho.dSYM
+RUN: llvm-dwarfdump %t.dir/dwarf5-dwarf4-combination-macho.dSYM \
+RUN:   -a --verbose | FileCheck %s
+
+
+CHECK:.debug_abbrev contents:
+CHECK-NEXT: Abbrev table for offset: 0x00000000
+
+CHECK: .debug_info contents:
+CHECK: 0x00000000: Compile Unit: length = 0x00000061, format = DWARF32, version = 0x0005, unit_type = DW_UT_compile, abbr_offset = 0x0000, addr_size = 0x08 
+CHECK: DW_AT_ranges [DW_FORM_sec_offset] (0x[[RANGELIST_OFFSET:[0-9a-f]+]]
+CHECK-NEXT:                  [0x[[RANGELIST_OFFSET_START:[0-9a-f]+]], 0x[[RANGELIST_OFFSET_END:[0-9a-f]+]]))
+CHECK-NEXT: DW_AT_addr_base [DW_FORM_sec_offset]      (0x00000008)
+CHECK: 0x00000037:   DW_TAG_subprogram [2] * (0x0000000c)
+CHECK-NEXT:  DW_AT_low_pc [DW_FORM_addrx]     (indexed (00000000) address = 0x[[#%.16x,LOCLIST_LOWPC:]])
+CHECK: 0x0000004d:     DW_TAG_formal_parameter [3]   (0x00000037)
+CHECK-NEXT:                   DW_AT_location [DW_FORM_sec_offset]   (0x[[LOCLIST_OFFSET:[0-9a-f]+]]: 
+CHECK-NEXT:                      [0x[[#%.16x,LOCLIST_PAIR_START:]], 0x[[#%.16x,LOCLIST_PAIR_END:]]): [[LOCLIST_EXPR:.*]]
+CHECK-NEXT:                      [0x[[#%.16x,LOCLIST_PAIR_START2:]], 0x[[#%.16x,LOCLIST_PAIR_END2:]]): [[LOCLIST_EXPR2:.*]])
+
+CHECK: 0x00000065: Compile Unit: length = 0x00000072, format = DWARF32, version = 0x0004, abbr_offset = 0x0058, addr_size = 0x08 
+CHECK:              DW_AT_low_pc [DW_FORM_addr]       (0x[[#%.16x,RANGE_LOWPC:]])
+CHECK-NEXT:              DW_AT_ranges [DW_FORM_sec_offset] (0x00000000
+CHECK-NEXT:                 [0x[[#%.16x,RANGE_START:]], 0x[[#%.16x,RANGE_END:]]))
+CHECK: 0x00000097:   DW_TAG_subprogram {{.*}} * (0x00000070)
+CHECK-NEXT:                DW_AT_low_pc [DW_FORM_addr]     (0x[[#%.16x,LOC_LOWPC:]])
+CHECK: 0x000000b4:     DW_TAG_formal_parameter [3]   (0x00000097)
+CHECK-NEXT:                  DW_AT_location [DW_FORM_sec_offset]   (0x[[LOC_OFFSET:[0-9a-f]+]]: 
+CHECK-NEXT:                     [0x[[#%.16x,LOC_PAIR_START:]], 0x[[#%.16x,LOC_PAIR_END:]]): [[LOC_EXPR:.*]]
+CHECK-NEXT:                     [0x[[#%.16x,LOC_PAIR_START2:]], 0x[[#%.16x,LOC_PAIR_END2:]]): [[LOC_EXPR2:.*]])
+
+CHECK: .debug_loc contents:
+CHECK-NEXT: 0x[[LOC_OFFSET]]:
+CHECK-NEXT:            (0x[[#sub(LOC_PAIR_START,LOC_LOWPC)]], 0x[[#sub(LOC_PAIR_END,LOC_LOWPC)]]): [[LOC_EXPR:.*]]
+CHECK-NEXT:            (0x[[#sub(LOC_PAIR_START2,LOC_LOWPC)]], 0x[[#sub(LOC_PAIR_END2,LOC_LOWPC)]]): [[LOC_EXPR2:.*]]
+
+CHECK: .debug_loclists contents:
+CHECK-NEXT: 0x00000000: locations list header: length = 0x00000018, format = DWARF32, version = 0x0005, addr_size = 0x08, seg_size = 0x00, offset_entry_count = 0x00000000
+CHECK-NEXT: 0x[[LOCLIST_OFFSET]]: 
+CHECK-NEXT:            DW_LLE_base_addressx   (0x0000000000000000)
+CHECK-NEXT:            DW_LLE_offset_pair     (0x[[#sub(LOCLIST_PAIR_START,LOCLIST_LOWPC)]], 0x[[#sub(LOCLIST_PAIR_END,LOCLIST_LOWPC)]])
+CHECK-NEXT:            DW_LLE_offset_pair     (0x[[#sub(LOCLIST_PAIR_START2,LOCLIST_LOWPC)]], 0x[[#sub(LOCLIST_PAIR_END2,LOCLIST_LOWPC)]])
+CHECK-NEXT:            DW_LLE_end_of_list     ()
+
+CHECK: .debug_line contents:
+CHECK-NEXT: debug_line[0x00000000]
+CHECK-NEXT: Line table prologue:
+CHECK-NEXT:     total_length: 0x00000048
+CHECK-NEXT:           format: DWARF32
+CHECK-NEXT:          version: 5
+CHECK-NEXT:     address_size: 8
+CHECK-NEXT:  seg_select_size: 0
+CHECK-NEXT:  prologue_length: 0x00000025
+CHECK-NEXT:  min_inst_length: 1
+CHECK-NEXT: max_ops_per_inst: 1
+CHECK-NEXT:  default_is_stmt: 1
+CHECK-NEXT:        line_base: -5
+CHECK-NEXT:       line_range: 14
+CHECK-NEXT:      opcode_base: 13
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_copy] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_advance_pc] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_advance_line] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_file] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_column] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_negate_stmt] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_basic_block] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_const_add_pc] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_fixed_advance_pc] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_prologue_end] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_epilogue_begin] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_isa] = 1
+CHECK-NEXT: include_directories[  0] =  .debug_line_str[0x00000000] = "/Users/shubham/Development/test109275485"
+CHECK-NEXT: file_names[  0]:
+CHECK-NEXT:            name:  .debug_line_str[0x00000029] = "a.cpp"
+CHECK-NEXT:       dir_index: 0
+
+CHECK: debug_line[0x0000004c]
+CHECK-NEXT: Line table prologue:
+CHECK-NEXT:     total_length: 0x0000003b
+CHECK-NEXT:           format: DWARF32
+CHECK-NEXT:          version: 4
+CHECK-NEXT:  prologue_length: 0x0000001d
+CHECK-NEXT:  min_inst_length: 1
+CHECK-NEXT: max_ops_per_inst: 1
+CHECK-NEXT:  default_is_stmt: 1
+CHECK-NEXT:        line_base: -5
+CHECK-NEXT:       line_range: 14
+CHECK-NEXT:      opcode_base: 13
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_copy] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_advance_pc] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_advance_line] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_file] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_column] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_negate_stmt] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_basic_block] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_const_add_pc] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_fixed_advance_pc] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_prologue_end] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_epilogue_begin] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_isa] = 1
+CHECK-NEXT: file_names[  1]:
+CHECK-NEXT:            name: "b.cpp"
+CHECK-NEXT:       dir_index: 0
+CHECK-NEXT:        mod_time: 0x00000000
+CHECK-NEXT:          length: 0x00000000
+
+CHECK: .debug_str contents:
+
+CHECK: .debug_line_str contents:
+CHECK-NEXT: 0x00000000: "/Users/shubham/Development/test109275485"
+CHECK-NEXT: 0x00000029: "a.cpp"
+
+CHECK: .debug_ranges contents:
+CHECK-NEXT: 00000000 [[#sub(RANGE_START,RANGE_LOWPC)]] [[#sub(RANGE_END,RANGE_LOWPC)]]
+
+CHECK: .debug_rnglists contents:
+CHECK-NEXT: 0x00000000: range list header: length = 0x0000000e, format = DWARF32, version = 0x0005, addr_size = 0x08, seg_size = 0x00, offset_entry_count = 0x00000000
+CHECK-NEXT: ranges:
+CHECK-NEXT: [[RANGELIST_OFFSET]]: [DW_RLE_base_addressx]:  0x0000000000000000
+CHECK-NEXT: 0x0000000e: [DW_RLE_offset_pair  ]: {{.*}}[0x[[RANGELIST_OFFSET_START]], 0x[[RANGELIST_OFFSET_END]])
+CHECK-NEXT: 0x00000011: [DW_RLE_end_of_list  ]

llvm/test/tools/dsymutil/ARM/DWARFLinkerParallel/dwarf5-macho.test

+; This test checks to that DWARF v5 debug info can be correctly linked
+; into a dSYM bundle by dsymutil, with the correct section names and DWARF v5
+; headers for the different sections.
+
+; 1.o was produced with the source file:
+
+; a.cpp
+; __attribute__((section("1,__text_foo"))) void foo() {}
+;
+; int foo2(int a) {
+;     return a+5;
+; }
+; int main () {
+;     return 1;
+; }
+
+; clang -g -c -O1 a.cpp -Xclang -gdwarf-5 -o 1.o
+
+
+RUN: rm -rf %t.dir && mkdir -p %t.dir
+RUN: dsymutil --linker llvm -y %p/../dummy-debug-map-amr64.map \
+RUN:   -oso-prepend-path=%p/../../Inputs/DWARF5 -o %t.dir/dwarf5-macho.dSYM
+RUN: llvm-dwarfdump %t.dir/dwarf5-macho.dSYM -a --verbose | FileCheck %s
+
+CHECK:.debug_abbrev contents:
+CHECK-NEXT: Abbrev table for offset: 0x00000000
+
+CHECK: .debug_info contents:
+CHECK-NEXT: Compile Unit: length = 0x00000061, format = DWARF32, version = 0x0005, unit_type = DW_UT_compile, abbr_offset = 0x0000, addr_size = 0x08 
+CHECK: DW_AT_ranges [DW_FORM_sec_offset] (0x[[RANGELIST_OFFSET:[0-9a-f]+]]
+CHECK-NEXT:                  [0x[[RANGELIST_OFFSET_START:[0-9a-f]+]], 0x[[RANGELIST_OFFSET_END:[0-9a-f]+]]))
+CHECK-NEXT: DW_AT_addr_base [DW_FORM_sec_offset]      (0x00000008)
+CHECK: 0x00000037:   DW_TAG_subprogram [2] * (0x0000000c)
+CHECK-NEXT:  DW_AT_low_pc [DW_FORM_addrx]     (indexed (00000000) address = 0x[[#%.16x,LOCLIST_LOWPC:]])
+CHECK: 0x0000004d:     DW_TAG_formal_parameter [3]   (0x00000037)
+CHECK-NEXT:                   DW_AT_location [DW_FORM_sec_offset]   (0x[[LOC_OFFSET:[0-9a-f]+]]: 
+CHECK-NEXT:                      [0x[[#%.16x,LOCLIST_PAIR_START:]], 0x[[#%.16x,LOCLIST_PAIR_END:]]): [[LOCLIST_EXPR:.*]]
+CHECK-NEXT:                      [0x[[#%.16x,LOCLIST_PAIR_START2:]], 0x[[#%.16x,LOCLIST_PAIR_END2:]]): [[LOCLIST_EXPR2:.*]])
+
+CHECK: .debug_loclists contents:
+CHECK-NEXT: 0x00000000: locations list header: length = 0x00000018, format = DWARF32, version = 0x0005, addr_size = 0x08, seg_size = 0x00, offset_entry_count = 0x00000000
+CHECK-NEXT: 0x[[LOC_OFFSET]]: 
+CHECK-NEXT:            DW_LLE_base_addressx   (0x0000000000000000)
+CHECK-NEXT:            DW_LLE_offset_pair     (0x[[#sub(LOCLIST_PAIR_START,LOCLIST_LOWPC)]], 0x[[#sub(LOCLIST_PAIR_END,LOCLIST_LOWPC)]])
+CHECK-NEXT:            DW_LLE_offset_pair     (0x[[#sub(LOCLIST_PAIR_START2,LOCLIST_LOWPC)]], 0x[[#sub(LOCLIST_PAIR_END2,LOCLIST_LOWPC)]])
+CHECK-NEXT:            DW_LLE_end_of_list     ()
+
+CHECK: .debug_line contents:
+CHECK-NEXT: debug_line[0x00000000]
+CHECK-NEXT: Line table prologue:
+CHECK-NEXT:     total_length: 0x00000048
+CHECK-NEXT:           format: DWARF32
+CHECK-NEXT:          version: 5
+CHECK-NEXT:     address_size: 8
+CHECK-NEXT:  seg_select_size: 0
+CHECK-NEXT:  prologue_length: 0x00000025
+CHECK-NEXT:  min_inst_length: 1
+CHECK-NEXT: max_ops_per_inst: 1
+CHECK-NEXT:  default_is_stmt: 1
+CHECK-NEXT:        line_base: -5
+CHECK-NEXT:       line_range: 14
+CHECK-NEXT:      opcode_base: 13
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_copy] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_advance_pc] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_advance_line] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_file] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_column] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_negate_stmt] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_basic_block] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_const_add_pc] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_fixed_advance_pc] = 1
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_prologue_end] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_epilogue_begin] = 0
+CHECK-NEXT: standard_opcode_lengths[DW_LNS_set_isa] = 1
+CHECK-NEXT: include_directories[  0] =  .debug_line_str[0x00000000] = "/Users/shubham/Development/test109275485"
+CHECK-NEXT: file_names[  0]:
+CHECK-NEXT:            name:  .debug_line_str[0x00000029] = "a.cpp"
+CHECK-NEXT:       dir_index: 0
+
+
+CHECK: .debug_str contents:
+
+CHECK: .debug_line_str contents:
+CHECK-NEXT: 0x00000000: "/Users/shubham/Development/test109275485"
+CHECK-NEXT: 0x00000029: "a.cpp"
+
+CHECK: .debug_rnglists contents:
+CHECK-NEXT: 0x00000000: range list header: length = 0x0000000e, format = DWARF32, version = 0x0005, addr_size = 0x08, seg_size = 0x00, offset_entry_count = 0x00000000
+CHECK-NEXT: ranges:
+CHECK-NEXT: [[RANGELIST_OFFSET]]: [DW_RLE_base_addressx]:  0x0000000000000000
+CHECK-NEXT: 0x0000000e: [DW_RLE_offset_pair  ]: {{.*}}[0x[[RANGELIST_OFFSET_START]], 0x[[RANGELIST_OFFSET_END]])
+CHECK-NEXT: 0x00000011: [DW_RLE_end_of_list  ]

llvm/test/tools/dsymutil/ARM/DWARFLinkerParallel/fat-dylib-update.test

+# REQUIRES: object-emission,system-darwin
+# RUN: dsymutil --linker llvm -oso-prepend-path %p/../..  %p/../../Inputs/fat-test.arm.dylib -o %t.dSYM
+# RUN: llvm-dwarfdump -a -v %t.dSYM/Contents/Resources/DWARF/fat-test.arm.dylib | FileCheck %s
+# RUN: dsymutil --linker llvm -u %t.dSYM
+# RUN: llvm-dwarfdump -a -v %t.dSYM/Contents/Resources/DWARF/fat-test.arm.dylib | FileCheck %s
+# RUN: dsymutil --linker llvm -u %t.dSYM -o %t1.dSYM
+# RUN: llvm-dwarfdump -a -v %t1.dSYM/Contents/Resources/DWARF/fat-test.arm.dylib | FileCheck %s
+
+CHECK: /Contents/Resources/DWARF/fat-test.arm.dylib(armv7): file format Mach-O arm
+
+CHECK: .debug_info contents:
+CHECK:  Compile Unit: length = 0x00000034, format = DWARF32, version = 0x0002, abbr_offset = 0x0000, addr_size = 0x04 (next unit at 0x00000038)
+CHECK:  DW_TAG_compile_unit [1] *
+CHECK:    DW_AT_producer [DW_FORM_strp] ( .debug_str[0x00000001] = "clang version 3.8.0 (trunk 243776)")
+CHECK:    DW_AT_language [DW_FORM_data2]  (DW_LANG_C99)
+CHECK:    DW_AT_name [DW_FORM_strp] ( .debug_str[0x00000024] = "fat-test.c")
+CHECK:    DW_AT_stmt_list [DW_FORM_data4] (0x00000000)
+CHECK:    DW_AT_comp_dir [DW_FORM_strp] ( .debug_str[0x0000002f] = "/Inputs")
+CHECK:    DW_TAG_variable [2]
+CHECK:      DW_AT_name [DW_FORM_strp] ( .debug_str[0x00000037] = "armv7_var")
+CHECK:      DW_AT_type [DW_FORM_ref4] (cu + 0x0030 => {0x00000030}
+CHECK:      DW_AT_external [DW_FORM_flag] (0x01)
+CHECK:      DW_AT_decl_file [DW_FORM_data1] ("/Inputs/fat-test.c")
+CHECK:      DW_AT_decl_line [DW_FORM_data1] (23)
+CHECK:      DW_AT_location [DW_FORM_block1] (DW_OP_addr 0x1000)
+CHECK:    DW_TAG_base_type [3]
+CHECK:      DW_AT_name [DW_FORM_strp] ( .debug_str[0x00000041] = "int")
+CHECK:      DW_AT_encoding [DW_FORM_data1]  (DW_ATE_signed)
+CHECK:      DW_AT_byte_size [DW_FORM_data1] (0x04)
+CHECK:    NULL
+
+
+CHECK: .debug_line contents:
+CHECK: Line table prologue:
+CHECK:     total_length: 0x0000002a
+CHECK:          version: 2
+CHECK:  prologue_length: 0x00000021
+CHECK:  min_inst_length: 1
+CHECK:  default_is_stmt: 1
+CHECK:        line_base: -5
+CHECK:       line_range: 14
+CHECK:      opcode_base: 13
+
+CHECK: /Contents/Resources/DWARF/fat-test.arm.dylib(armv7s):  file format Mach-O arm
+
+CHECK: .debug_info contents:
+CHECK:  Compile Unit: length = 0x00000034, format = DWARF32, version = 0x0002, abbr_offset = 0x0000, addr_size = 0x04 (next unit at 0x00000038)
+CHECK:  DW_TAG_compile_unit [1] *
+CHECK:    DW_AT_producer [DW_FORM_strp] ( .debug_str[0x00000001] = "clang version 3.8.0 (trunk 243776)")
+CHECK:    DW_AT_language [DW_FORM_data2]  (DW_LANG_C99)
+CHECK:    DW_AT_name [DW_FORM_strp] ( .debug_str[0x00000024] = "fat-test.c")
+CHECK:    DW_AT_stmt_list [DW_FORM_data4] (0x00000000)
+CHECK:    DW_AT_comp_dir [DW_FORM_strp] ( .debug_str[0x0000002f] = "/Inputs")
+CHECK:    DW_TAG_variable [2]
+CHECK:      DW_AT_name [DW_FORM_strp] ( .debug_str[0x00000037] = "armv7s_var")
+CHECK:      DW_AT_type [DW_FORM_ref4] (cu + 0x0030 => {0x00000030}
+CHECK:      DW_AT_external [DW_FORM_flag] (0x01)
+CHECK:      DW_AT_decl_file [DW_FORM_data1] ("/Inputs/fat-test.c")
+CHECK:      DW_AT_decl_line [DW_FORM_data1] (21)
+CHECK:      DW_AT_location [DW_FORM_block1] (DW_OP_addr 0x1000)
+CHECK:    DW_TAG_base_type [3]
+CHECK:      DW_AT_name [DW_FORM_strp] ( .debug_str[0x00000042] = "int")
+CHECK:      DW_AT_encoding [DW_FORM_data1]  (DW_ATE_signed)
+CHECK:      DW_AT_byte_size [DW_FORM_data1] (0x04)
+CHECK:    NULL
+
+CHECK: .debug_line contents:
+CHECK: Line table prologue:
+CHECK:     total_length: 0x0000002a
+CHECK:          version: 2
+CHECK:  prologue_length: 0x00000021
+CHECK:  min_inst_length: 1
+CHECK:  default_is_stmt: 1
+CHECK:        line_base: -5
+CHECK:       line_range: 14
+CHECK:      opcode_base: 13
+
+CHECK: /Contents/Resources/DWARF/fat-test.arm.dylib(arm64): file format Mach-O arm64
+
+CHECK: .debug_info contents:
+CHECK:  Compile Unit: length = 0x00000038, format = DWARF32, version = 0x0002, abbr_offset = 0x0000, addr_size = 0x08 (next unit at 0x0000003c)
+CHECK:  DW_TAG_compile_unit [1] *
+CHECK:    DW_AT_producer [DW_FORM_strp] ( .debug_str[0x00000001] = "clang version 3.8.0 (trunk 243776)")
+CHECK:    DW_AT_language [DW_FORM_data2]  (DW_LANG_C99)
+CHECK:    DW_AT_name [DW_FORM_strp] ( .debug_str[0x00000024] = "fat-test.c")
+CHECK:    DW_AT_stmt_list [DW_FORM_data4] (0x00000000)
+CHECK:    DW_AT_comp_dir [DW_FORM_strp] ( .debug_str[0x0000002f] = "/Inputs")
+CHECK:    DW_TAG_variable [2]
+CHECK:      DW_AT_name [DW_FORM_strp] ( .debug_str[0x00000037] = "arm64_var")
+CHECK:      DW_AT_type [DW_FORM_ref4] (cu + 0x0034 => {0x00000034}
+CHECK:      DW_AT_external [DW_FORM_flag] (0x01)
+CHECK:      DW_AT_decl_file [DW_FORM_data1] ("/Inputs/fat-test.c")
+CHECK:      DW_AT_decl_line [DW_FORM_data1] (25)
+CHECK:      DW_AT_location [DW_FORM_block1] (DW_OP_addr 0x4000)
+CHECK:    DW_TAG_base_type [3]
+CHECK:      DW_AT_name [DW_FORM_strp] ( .debug_str[0x00000041] = "int")
+CHECK:      DW_AT_encoding [DW_FORM_data1]  (DW_ATE_signed)
+CHECK:      DW_AT_byte_size [DW_FORM_data1] (0x04)
+CHECK:    NULL
+
+CHECK: .debug_line contents:
+CHECK: Line table prologue:
+CHECK:     total_length: 0x0000002a
+CHECK:          version: 2
+CHECK:  prologue_length: 0x00000021
+CHECK:  min_inst_length: 1
+CHECK:  default_is_stmt: 1
+CHECK:        line_base: -5
+CHECK:       line_range: 14
+CHECK:      opcode_base: 13

llvm/test/tools/dsymutil/ARM/DWARFLinkerParallel/obfuscated.test

+REQUIRES: system-darwin
+
+RUN: dsymutil --linker llvm --symbol-map %p/../../Inputs/obfuscated.map %p/../../Inputs/obfuscated.arm64 -f -o - \
+RUN:     | llvm-dwarfdump -v - \
+RUN:     | FileCheck %s
+
+RUN: dsymutil --linker llvm --symbol-map %p/../../Inputs/obfuscated.map %p/../../Inputs/obfuscated.arm64 -f -o - \
+RUN:     | llvm-dwarfdump -v - \
+RUN:     | FileCheck --check-prefix=NOHIDDEN %s
+
+RUN: dsymutil --linker llvm --symbol-map %p/../../Inputs/obfuscated.2.map %p/../../Inputs/obfuscated.2.arm64 -f -o - \
+RUN:     | llvm-dwarfdump -v - \
+RUN:     | FileCheck --check-prefix=NOHIDDEN %s
+
+// Run with plist and make sure dsymutil finds it.
+RUN: mkdir -p %t.dSYM/Contents/Resources/DWARF/
+RUN: mkdir -p %t.mapdir
+RUN: cp %p/../../Inputs/obfuscated.arm64 %t.dSYM/Contents/Resources/DWARF/
+RUN: cp %p/../../Inputs/E828A486-8433-3A5E-B6DB-A6294D28133D.plist %t.dSYM/Contents/Resources/
+RUN: cp %p/../../Inputs/obfuscated.map %t.mapdir/506AA50A-6B26-3B37-86D2-DC6EBD57B720.bcsymbolmap
+RUN: dsymutil --linker llvm --symbol-map %t.mapdir %t.dSYM 2>&1 | FileCheck --check-prefix=OBFUSCATING %s
+
+// Run without plist and make sure dsymutil doesn't crash.
+RUN: rm %t.dSYM/Contents/Resources/E828A486-8433-3A5E-B6DB-A6294D28133D.plist
+RUN: dsymutil --linker llvm --symbol-map %t.mapdir %t.dSYM 2>&1 | FileCheck --check-prefix=NOTOBFUSCATING %s
+
+OBFUSCATING-NOT: not unobfuscating
+
+NOTOBFUSCATING: not unobfuscating
+
+NOHIDDEN-NOT: __hidden#
+
+CHECK: .debug_info contents:
+
+CHECK: DW_TAG_compile_unit [1] *
+CHECK:    DW_AT_producer [DW_FORM_strp]    ( {{.*}} "Apple LLVM version 7.0.0 (clang-700.2.38.2)")
+CHECK:    DW_AT_name [DW_FORM_strp]        ( {{.*}} "main.c")
+CHECK:    DW_AT_comp_dir [DW_FORM_strp]    ( {{.*}} "/Users/steven/dev/alpena/tests/src")
+CHECK:    DW_TAG_subprogram [2]
+CHECK:      DW_AT_name [DW_FORM_strp]      ( {{.*}} "main")
+
+CHECK:  DW_TAG_compile_unit [1] *
+CHECK:    DW_AT_producer [DW_FORM_strp]    ( {{.*}} "Apple LLVM version 7.0.0 (clang-700.2.38.2)")
+CHECK:    DW_AT_name [DW_FORM_strp]        ( {{.*}} "one.c")
+CHECK:    DW_AT_comp_dir [DW_FORM_strp]    ( {{.*}} "/Users/steven/dev/alpena/tests/src")
+CHECK:    DW_TAG_subprogram [2]
+CHECK:      DW_AT_name [DW_FORM_strp]      ( {{.*}} "one")
+
+CHECK:  DW_TAG_compile_unit [1] *
+CHECK:    DW_AT_producer [DW_FORM_strp]    ( {{.*}} "Apple LLVM version 7.0.0 (clang-700.2.38.2)")
+CHECK:    DW_AT_name [DW_FORM_strp]        ( {{.*}} "two.c")
+CHECK:    DW_AT_comp_dir [DW_FORM_strp]    ( {{.*}} "/Users/steven/dev/alpena/tests/src")
+CHECK:    DW_TAG_subprogram [2]
+CHECK:      DW_AT_name [DW_FORM_strp]      ( {{.*}} "two")
+
+CHECK:  DW_TAG_compile_unit [1] *
+CHECK:    DW_AT_producer [DW_FORM_strp]    ( {{.*}} "Apple LLVM version 7.0.0 (clang-700.2.38.2)")
+CHECK:    DW_AT_name [DW_FORM_strp]        ( {{.*}} "three.c")
+CHECK:    DW_AT_comp_dir [DW_FORM_strp]    ( {{.*}} "/Users/steven/dev/alpena/tests/src")
+CHECK:    DW_TAG_subprogram [2]
+CHECK:      DW_AT_name [DW_FORM_strp]      ( {{.*}} "three")
+
+CHECK:  DW_TAG_compile_unit [1] *
+CHECK:    DW_AT_producer [DW_FORM_strp]    ( {{.*}} "Apple LLVM version 7.0.0 (clang-700.2.38.2)")
+CHECK:    DW_AT_name [DW_FORM_strp]        ( {{.*}} "four.c")
+CHECK:    DW_AT_stmt_list [DW_FORM_data4]  (0x0000011e)
+CHECK:    DW_AT_comp_dir [DW_FORM_strp]    ( {{.*}} "/Users/steven/dev/alpena/tests/src")
+CHECK:    DW_TAG_subprogram [2]
+CHECK:      DW_AT_name [DW_FORM_strp]      ( {{.*}} "four")
+
+CHECK:  DW_TAG_compile_unit [1] *
+CHECK:    DW_AT_producer [DW_FORM_strp]    ( {{.*}} "Apple LLVM version 7.0.0 (clang-700.2.38.2)")
+CHECK:    DW_AT_name [DW_FORM_strp]        ( {{.*}} "five.c")
+CHECK:    DW_AT_comp_dir [DW_FORM_strp]    ( {{.*}} "/Users/steven/dev/alpena/tests/src")
+CHECK:    DW_TAG_subprogram [2]
+CHECK:      DW_AT_name [DW_FORM_strp]      ( {{.*}} "five")
+
+CHECK:  DW_TAG_compile_unit [1] *
+CHECK:    DW_AT_producer [DW_FORM_strp]    ( {{.*}} "Apple LLVM version 7.0.0 (clang-700.2.38.2)")
+CHECK:    DW_AT_name [DW_FORM_strp]        ( {{.*}} "six.c")
+CHECK:    DW_AT_comp_dir [DW_FORM_strp]    ( {{.*}} "/Users/steven/dev/alpena/tests/src")
+CHECK:    DW_TAG_subprogram [2]
+CHECK:      DW_AT_name [DW_FORM_strp]      ( {{.*}} "six")
+
+CHECK: .debug_line contents:
+CHECK: file_names[  1]:
+CHECK:            name: "main.c"
+CHECK:       dir_index: 0
+CHECK:        mod_time: 0x00000000
+CHECK: file_names[  1]:
+CHECK:            name: "one.c"
+CHECK:       dir_index: 0
+CHECK:        mod_time: 0x00000000
+CHECK:          length: 0x00000000
+CHECK: file_names[  1]:
+CHECK:            name: "two.c"
+CHECK:       dir_index: 0
+CHECK:        mod_time: 0x00000000
+CHECK:          length: 0x00000000
+CHECK: file_names[  1]:
+CHECK:            name: "three.c"
+CHECK:       dir_index: 0
+CHECK:        mod_time: 0x00000000
+CHECK:          length: 0x00000000
+CHECK: file_names[  1]:
+CHECK:            name: "four.c"
+CHECK:       dir_index: 0
+CHECK:        mod_time: 0x00000000
+CHECK:          length: 0x00000000
+CHECK: file_names[  1]:
+CHECK:            name: "five.c"
+CHECK:       dir_index: 0
+CHECK:        mod_time: 0x00000000
+CHECK:          length: 0x00000000
+CHECK: file_names[  1]:
+CHECK:            name: "six.c"
+CHECK:       dir_index: 0
+CHECK:        mod_time: 0x00000000
+CHECK:          length: 0x00000000

llvm/test/tools/dsymutil/ARM/call-pc-reloc.test

 # Adding `-isysroot $(xcrun -sdk iphoneos.internal -show-sdk-path)` can fix
 # linker warnings when building on macOS.
 $ clang -arch arm64 main.cpp -o main.arm64.o -c -g -O2
 $ clang -arch arm64 main.arm64.o -o main.arm64 -g
 
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/call_pc/main.arm64 -o %t.dSYM
 RUN: llvm-dwarfdump %t.dSYM | FileCheck %s -implicit-check-not=DW_AT_call_pc
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/call_pc/main.arm64 -o %t.dSYM
+RUN: llvm-dwarfdump %t.dSYM | FileCheck %s -implicit-check-not=DW_AT_call_pc
+
 CHECK: DW_AT_call_pc (0x0000000100007f94)

llvm/test/tools/dsymutil/ARM/dwarf5-addr_base.test

 
 ; clang -g -c -O1 c.cpp -gdwarf-5 -o 3.o
 
 
 RUN: rm -rf %t.dir && mkdir -p %t.dir
 RUN: dsymutil -y %p/dummy-debug-map-amr64.map -oso-prepend-path=%p/../Inputs/DWARF5-addr_base -o %t.dir/dwarf5-addr_base.dSYM
 RUN: llvm-dwarfdump %t.dir/dwarf5-addr_base.dSYM -a --verbose | FileCheck %s
 
+RUN: dsymutil --linker llvm -y %p/dummy-debug-map-amr64.map \
+RUN:   -oso-prepend-path=%p/../Inputs/DWARF5-addr_base \
+RUN:   -o %t.dir/dwarf5-addr_base.dSYM
+RUN: llvm-dwarfdump %t.dir/dwarf5-addr_base.dSYM -a --verbose | FileCheck %s
+
 RUN: dsymutil --update -y %p/dummy-debug-map-amr64.map -oso-prepend-path=%p/../Inputs/DWARF5-addr_base -o %t.dir/dwarf5-addr_base.dSYM
 RUN: llvm-dwarfdump %t.dir/dwarf5-addr_base.dSYM -a --verbose | FileCheck %s --check-prefix=UPD
 
+RUN: dsymutil --linker llvm --update -y %p/dummy-debug-map-amr64.map \
+RUN:   -oso-prepend-path=%p/../Inputs/DWARF5-addr_base \
+RUN:   -o %t.dir/dwarf5-addr_base.dSYM
+RUN: llvm-dwarfdump %t.dir/dwarf5-addr_base.dSYM -a --verbose | \
+RUN:   FileCheck %s --check-prefix=UPD
+
 CHECK: .debug_info contents:
 CHECK-NEXT: 0x00000000: Compile Unit: length = 0x00000061, format = DWARF32, version = 0x0005, unit_type = DW_UT_compile, abbr_offset = 0x0000, addr_size = 0x08 (next unit at 0x00000065)
 
 CHECK: 0x0000000c: DW_TAG_compile_unit [1] *
 CHECK:               DW_AT_addr_base [DW_FORM_sec_offset]      (0x00000008)
 
 CHECK: 0x00000037:   DW_TAG_subprogram [2] * (0x0000000c)
 CHECK-NEXT:                DW_AT_low_pc [DW_FORM_addrx]    (indexed (00000000) address = 0x[[ADDR1:[0-9a-f]+]])
 
 
-CHECK: 0x00000065: Compile Unit: length = 0x00000061, format = DWARF32, version = 0x0005, unit_type = DW_UT_compile, abbr_offset = 0x0000, addr_size = 0x08 (next unit at 0x000000ca)
+CHECK: 0x00000065: Compile Unit: length = 0x00000061, format = DWARF32, version = 0x0005, unit_type = DW_UT_compile, abbr_offset = 0x00{{00|58}}, addr_size = 0x08 (next unit at 0x000000ca)
 
 CHECK: 0x00000071: DW_TAG_compile_unit [1] *
 CHECK:              DW_AT_addr_base [DW_FORM_sec_offset]      (0x00000018)
 
 CHECK: 0x0000009c:   DW_TAG_subprogram [2] * (0x00000071)
 CHECK-NEXT:                 DW_AT_low_pc [DW_FORM_addrx]    (indexed (00000000) address = 0x[[ADDR2:[0-9a-f]+]])
 
-CHECK: 0x000000ca: Compile Unit: length = 0x0000005a, format = DWARF32, version = 0x0005, unit_type = DW_UT_compile, abbr_offset = 0x0000, addr_size = 0x08 (next unit at 0x00000128)
+CHECK: 0x000000ca: Compile Unit: length = 0x0000005a, format = DWARF32, version = 0x0005, unit_type = DW_UT_compile, abbr_offset = 0x00{{00|b0}}, addr_size = 0x08 (next unit at 0x00000128)
 
-CHECK: 0x000000d6: DW_TAG_compile_unit [5] *
+CHECK: 0x000000d6: DW_TAG_compile_unit {{.*}} *
 CHECK: DW_AT_addr_base [DW_FORM_sec_offset]      (0x00000028)
 
 CHECK: 0x000000fa:   DW_TAG_subprogram [2] * (0x000000d6)
 CHECK-NEXT:                 DW_AT_low_pc [DW_FORM_addrx]    (indexed (00000000) address = 0x[[ADDR3:[0-9a-f]+]])
 
 CHECK: .debug_addr contents:
 CHECK-NEXT: 0x00000000: Address table header: length = 0x0000000c, format = DWARF32, version = 0x0005, addr_size = 0x08, seg_size = 0x00
 CHECK-NEXT: Addrs: [

 
 UPD: 0x00000071:   DW_TAG_subprogram [3] * (0x0000000c)
 UPD-NEXT:                 DW_AT_low_pc [DW_FORM_addrx]    (indexed (00000002) address = 0x0000000000000008)
 
 UPD: 0x00000094:   DW_TAG_subprogram [5]   (0x0000000c)
 UPD-NEXT:                 DW_AT_low_pc [DW_FORM_addrx]    (indexed (00000003) address = 0x0000000000000010)
 
 
-UPD: 0x000000ae: Compile Unit: length = 0x00000098, format = DWARF32, version = 0x0005, unit_type = DW_UT_compile, abbr_offset = 0x0000, addr_size = 0x08 (next unit at 0x0000014a)
+UPD: 0x000000ae: Compile Unit: length = 0x00000098, format = DWARF32, version = 0x0005, unit_type = DW_UT_compile, abbr_offset = 0x00{{00|97}}, addr_size = 0x08 (next unit at 0x0000014a)
 
 UPD: 0x000000ba: DW_TAG_compile_unit [1] *
 UPD:              DW_AT_addr_base [DW_FORM_sec_offset]      (0x00000008)
 
 UPD: 0x000000ea:   DW_TAG_subprogram [2]   (0x000000ba)
 UPD-NEXT:                 DW_AT_low_pc [DW_FORM_addrx]    (indexed (00000000) address = 0x0000000000000018)
 
 UPD: 0x000000fc:   DW_TAG_subprogram [3] * (0x000000ba)
 UPD-NEXT:                 DW_AT_low_pc [DW_FORM_addrx]    (indexed (00000001) address = 0x0000000000000000)
 
 UPD: 0x0000011f:   DW_TAG_subprogram [3] * (0x000000ba)
 UPD-NEXT:                 DW_AT_low_pc [DW_FORM_addrx]    (indexed (00000002) address = 0x0000000000000008)
 
-UPD: 0x0000014a: Compile Unit: length = 0x0000005b, format = DWARF32, version = 0x0005, unit_type = DW_UT_compile, abbr_offset = 0x0000, addr_size = 0x08 (next unit at 0x000001a9)
+UPD: 0x0000014a: Compile Unit: length = 0x0000005b, format = DWARF32, version = 0x0005, unit_type = DW_UT_compile, abbr_offset = 0x0{{000|111}}, addr_size = 0x08 (next unit at 0x000001a9)
 
-UPD: 0x00000156: DW_TAG_compile_unit [7] *
+UPD: 0x00000156: DW_TAG_compile_unit {{.*}} *
 UPD: DW_AT_addr_base [DW_FORM_sec_offset]      (0x00000008)
 
-UPD: 0x0000017e:   DW_TAG_subprogram [3] * (0x00000156)
+UPD: 0x0000017e:   DW_TAG_subprogram {{.*}} * (0x00000156)
 UPD-NEXT:                 DW_AT_low_pc [DW_FORM_addrx]    (indexed (00000000) address = 0x0000000000000018)
 
 UPD: .debug_addr contents:
 UPD-NEXT: 0x00000000: Address table header: length = 0x00000024, format = DWARF32, version = 0x0005, addr_size = 0x08, seg_size = 0x00
 UPD-NEXT: Addrs: [
 UPD-NEXT: 0x0000000000000018
 UPD-NEXT: 0x0000000000000000
 UPD-NEXT: 0x0000000000000008

llvm/test/tools/dsymutil/ARM/dwarf5-addrx-0x0-last.test

 DEBUGADDR: 0x0000000000000000
 DEBUGADDR: ]
 
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/dwarf5/dwarf5-addrx-0x0-last.out -o %t.dSYM 2>&1 | FileCheck %s --allow-empty
 RUN: llvm-dwarfdump --verify %t.dSYM 2>&1 | FileCheck %s
 RUN: llvm-dwarfdump --verbose -debug-info %t.dSYM | FileCheck %s --check-prefix DEBUGINFO
 RUN: llvm-dwarfdump --verbose -debug-line %t.dSYM | FileCheck %s --check-prefix DEBUGLINE
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs \
+RUN:   %p/../Inputs/private/tmp/dwarf5/dwarf5-addrx-0x0-last.out \
+RUN:   -o %t.dSYM 2>&1 | FileCheck %s --allow-empty
+RUN: llvm-dwarfdump --verify %t.dSYM 2>&1 | FileCheck %s
+RUN: llvm-dwarfdump --verbose -debug-info %t.dSYM | FileCheck %s --check-prefix DEBUGINFO
+RUN: llvm-dwarfdump --verbose -debug-line %t.dSYM | FileCheck %s --check-prefix DEBUGLINE
+
+
 CHECK-NOT: error:
 
 DEBUGINFO:   DW_TAG_subprogram
 DEBUGINFO:     DW_AT_low_pc [DW_FORM_addrx]      (indexed (00000000) address = 0x0000000100003f4c)
 DEBUGINFO:     DW_AT_high_pc [DW_FORM_data4]   (0x00000054)
 DEBUGINFO:     DW_AT_name [DW_FORM_strp]       ( .debug_str[0x0000011c] = "main")
 
 DEBUGLINE:  0x0000000100003f4c   4   0  {{.*}}  is_stmt
 DEBUGLINE:  0x0000000100003f6c   5  17  {{.*}}  is_stmt prologue_end
 DEBUGLINE:  0x0000000100003f70   5  22  {{.*}}
 DEBUGLINE:  0x0000000100003f74   5   7  {{.*}}
 DEBUGLINE:  0x0000000100003f78   6   3  {{.*}}  is_stmt
 DEBUGLINE:  0x0000000100003f84   7   3  {{.*}}  is_stmt
 DEBUGLINE:  0x0000000100003f94   9   3  {{.*}}  is_stmt epilogue_begin
 DEBUGLINE:  0x0000000100003fa0   9   3  {{.*}}  is_stmt end_sequence

llvm/test/tools/dsymutil/ARM/empty-map.test

 # RUN: dsymutil -f -oso-prepend-path=%p/../Inputs -y %s -o - 2>&1 | FileCheck %s
 
+# RUN: dsymutil --linker llvm -f -oso-prepend-path=%p/../Inputs -y %s -o - 2>&1 | FileCheck %s
+
 ---
 triple:          'thumbv7-apple-darwin'
 ...
 
 # CHECK: warning: no debug symbols in executable (-arch armv7)

llvm/test/tools/dsymutil/ARM/extern-alias.test

 _foo _baz
 
 $ xcrun --sdk iphoneos clang -g private_extern.c -c -o private_extern.o -target arm64-apple-ios14.0
 $ xcrun --sdk iphoneos clang -g main.c -c -o main.o -target arm64-apple-ios14.0
 $ xcrun --sdk iphoneos clang private_extern.o main.o -target arm64-apple-ios14.0 -o private_extern.out -Xlinker -alias_list -Xlinker alias_list
 
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/private_extern/private_extern.out -o %t.dSYM --verbose | FileCheck %s
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/extern/extern.out -o %t.dSYM --verbose | FileCheck %s
+
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/private_extern/private_extern.out -o %t.dSYM --verbose | FileCheck %s
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/extern/extern.out -o %t.dSYM --verbose | FileCheck %s
+
 CHECK-NOT: could not find object file symbol for symbol _baz
 CHECK: { sym: _baz, objAddr: 0x0, binAddr: 0x100007F58, size: 0x0 }
 CHECK: { sym: _foo, objAddr: 0x0, binAddr: 0x100007F58, size: 0x20 }

llvm/test/tools/dsymutil/ARM/fat-arch-name.test

 # RUN: dsymutil -no-output %p/../Inputs/fat-test.arm.dylib -o /dev/null -verbose 2>&1 | FileCheck %s
 
+# RUN: dsymutil --linker llvm -no-output %p/../Inputs/fat-test.arm.dylib -o /dev/null -verbose 2>&1 | FileCheck %s
+
 # We detect thumb triples from the binaries, because those are the only ones
 # that are guaranteed to be able to generate a Target instance (for example
 # we would detect armv7m-apple-darwin as non-thumb triple, but you can't
 # instantiate a Target from that). In the user-visible architecture names, and
 # in the lipo invocation, we need to rewrite the thumb arch names to the arm
 # ones.
 
 # CHECK: warning: no debug symbols in executable (-arch armv7)

llvm/test/tools/dsymutil/ARM/fat-arch-not-found.test

 # RUN: dsymutil -f -oso-prepend-path=%p/../Inputs -y %s -o - 2>&1 | FileCheck %s
+#
+# RUN: dsymutil --linker llvm -f -oso-prepend-path=%p/../Inputs -y %s -o - 2>&1 | FileCheck %s
 
 ---
 triple:          'armv7-apple-darwin'
 objects:
   - filename: libfat-test.a(fat-test.o)
     symbols:
       - { sym: _armv7_var, objAddr: 0x0, binAddr: 0x1000, size: 0x4 }
 ...
 
 # CHECK: libfat-test.a(fat-test.o): No object file for requested architecture
 

llvm/test/tools/dsymutil/ARM/inlined-low_pc.c

 /* Compiled with: clang -arch=arm64 -O2 -g -c inlined_low_pc.c */
 
 static int foo(int i) { return 42 + i; }
 int bar(int a) { return foo(a); }
 
 // RUN: dsymutil -f -y %p/dummy-debug-map-amr64.map -oso-prepend-path %p/../Inputs/inlined-low_pc -o - | llvm-dwarfdump - | FileCheck %s
 
+// RUN: dsymutil --linker llvm -f -y %p/dummy-debug-map-amr64.map \
+// RUN: -oso-prepend-path %p/../Inputs/inlined-low_pc -o - | \
+// RUN: llvm-dwarfdump - | FileCheck %s
+
 // CHECK: DW_TAG_subprogram
 // CHECK: DW_AT_low_pc{{.*}}0x0000000000010000
 // CHECK: DW_AT_name{{.*}}"bar"
 // CHECK-NOT: NULL
 // CHECK: DW_TAG_inlined_subroutine
 // CHECK-NEXT: DW_AT_abstract_origin{{.*}}"foo"
 // CHECK-NEXT: DW_AT_low_pc{{.*}}0x0000000000010000
 

llvm/test/tools/dsymutil/ARM/preload.test

 $ cat foo.c
 void start(void) asm("start");
 void start(void) {}
 $ xcrun clang -c -o foo.o foo.c -g3
 $ xcrun clang -o foo foo.o -g3 -Wl,-preload -nodefaultlibs
 
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/preload/foo -o %t.dSYM
 RUN: llvm-nm %p/../Inputs/private/tmp/preload/foo | FileCheck %s
 RUN: llvm-nm %t.dSYM/Contents/Resources/DWARF/foo | FileCheck %s
+
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/preload/foo -o %t.dSYM
+RUN: llvm-nm %p/../Inputs/private/tmp/preload/foo | FileCheck %s
+RUN: llvm-nm %t.dSYM/Contents/Resources/DWARF/foo | FileCheck %s
+
 CHECK: start

llvm/test/tools/dsymutil/ARM/scattered.c

-RUN: dsymutil -y %p/dummy-debug-map.map -oso-prepend-path %p/../Inputs/scattered-reloc/ -f -o - | llvm-dwarfdump -debug-info - | FileCheck %s
+RUN: dsymutil -y %p/dummy-debug-map.map -oso-prepend-path \
+RUN:  %p/../Inputs/scattered-reloc/ -f -o - | \
+RUN:  llvm-dwarfdump -debug-info - | FileCheck %s
+
+RUN: dsymutil --linker llvm -y %p/dummy-debug-map.map \
+RUN:  -oso-prepend-path %p/../Inputs/scattered-reloc/ -f -o - \
+RUN:  | llvm-dwarfdump -debug-info - | FileCheck %s
 
 // See Inputs/scattered-reloc/scattered.s to see how this test
 // actually works.
 int bar = 42;
 
 CHECK: DW_TAG_variable
 CHECK-NOT: DW_TAG
 CHECK: DW_AT_name{{.*}}
 "bar" CHECK - NOT : DW_TAG
-                        CHECK : DW_AT_location{{.*}}(DW_OP_addr 0x10010)

llvm/test/tools/dsymutil/ARM/thumb.c

 // RUN: dsymutil -f -oso-prepend-path=%p/.. %p/../Inputs/thumb.armv7m -o - | llvm-dwarfdump - | FileCheck %s
 // RUN: dsymutil -arch armv7m -f -oso-prepend-path=%p/.. %p/../Inputs/thumb.armv7m -o - | llvm-dwarfdump - | FileCheck %s
 
+// RUN: dsymutil --linker llvm -f -oso-prepend-path=%p/.. \
+// RUN:  %p/../Inputs/thumb.armv7m -o - | llvm-dwarfdump - | FileCheck %s
+// RUN: dsymutil --linker llvm -arch armv7m -f -oso-prepend-path=%p/.. \
+// RUN:  %p/../Inputs/thumb.armv7m -o - | llvm-dwarfdump - | FileCheck %s
+
 /* Compile with:
    clang -c thumb.c -arch armv7m -g
    clang thumb.o -o thumb.armv7m -arch armv7m -nostdlib -static -Wl,-e,_start
 */
 
 void start() {
 }
 
 CHECK: DW_AT_name{{.*}}"thumb.c"
 CHECK: DW_AT_name{{.*}}"start"

llvm/test/tools/dsymutil/X86/DWARFLinkerParallel/basic-linking-bundle.test

+RUN: rm -rf %t
+RUN: mkdir -p %t/dsymdest
+RUN: cat %p/../../Inputs/basic.macho.x86_64 > %t/basic.macho.x86_64
+
+RUN: dsymutil --linker llvm -accelerator=Pub -oso-prepend-path=%p/../.. %t/basic.macho.x86_64
+
+Check that the object file in the bundle exists and is sane:
+RUN: llvm-dwarfdump -a %t/basic.macho.x86_64.dSYM/Contents/Resources/DWARF/basic.macho.x86_64 | FileCheck %S/basic-linking-x86.test
+
+Check that we don't create an empty Remarks directory if there are no remarks.
+RUN: not ls %t/basic.macho.x86_64.dSYM/Contents/Resources/Remarks
+
+Check that llvm-dwarfdump -a recognizes the bundle as a dSYM:
+RUN: llvm-dwarfdump -a %t/basic.macho.x86_64.dSYM | FileCheck %S/basic-linking-x86.test
+
+RUN: FileCheck %s --input-file %t/basic.macho.x86_64.dSYM/Contents/Info.plist
+
+RUN: dsymutil --linker llvm -oso-prepend-path=%p/../.. %t/basic.macho.x86_64 -o %t/dsymdest/basic.macho.x86_64.dSYM
+RUN: llvm-dwarfdump -a %t/dsymdest/basic.macho.x86_64.dSYM/Contents/Resources/DWARF/basic.macho.x86_64 | FileCheck %S/basic-linking-x86.test
+RUN: FileCheck %s --input-file %t/dsymdest/basic.macho.x86_64.dSYM/Contents/Info.plist
+
+CHECK: <?xml version="1.0" encoding="UTF-8"?>
+CHECK-NEXT: <!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+CHECK-NEXT: <plist version="1.0">
+CHECK-NEXT:         <dict>
+CHECK-NEXT:                 <key>CFBundleDevelopmentRegion</key>
+CHECK-NEXT:                 <string>English</string>
+CHECK-NEXT:                 <key>CFBundleIdentifier</key>
+CHECK-NEXT:                 <string>com.apple.xcode.dsym.basic.macho.x86_64</string>
+CHECK-NEXT:                 <key>CFBundleInfoDictionaryVersion</key>
+CHECK-NEXT:                 <string>6.0</string>
+CHECK-NEXT:                 <key>CFBundlePackageType</key>
+CHECK-NEXT:                 <string>dSYM</string>
+CHECK-NEXT:                 <key>CFBundleSignature</key>
+CHECK-NEXT:                 <string>????</string>
+CHECK-NEXT:                 <key>CFBundleShortVersionString</key>
+CHECK-NEXT:                 <string>1.0</string>
+CHECK-NEXT:                 <key>CFBundleVersion</key>
+CHECK-NEXT:                 <string>1</string>
+CHECK-NEXT:         </dict>
+CHECK-NEXT: </plist>

llvm/test/tools/dsymutil/X86/DWARFLinkerParallel/basic-linking-x86.test

 RUN: cat %p/../../Inputs/basic.macho.x86_64 > %t1
-RUN: dsymutil --linker llvm --no-output -accelerator=Pub -f -oso-prepend-path=%p/../.. %t1 2>&1 | FileCheck %s --allow-empty
+RUN: dsymutil --linker llvm -accelerator=Pub -f -oso-prepend-path=%p/../.. %t1
+RUN: llvm-dwarfdump -a %t1.dwarf | FileCheck %s
+RUN: dsymutil --linker llvm -accelerator=Pub -f -o %t2 -oso-prepend-path=%p/../.. %p/../../Inputs/basic.macho.x86_64
+RUN: llvm-dwarfdump -a %t2 | FileCheck %s
+RUN: dsymutil --linker llvm -accelerator=Pub -f -o - -oso-prepend-path=%p/../.. %p/../../Inputs/basic.macho.x86_64 | llvm-dwarfdump -a - | FileCheck %s --check-prefixes=CHECK,BASIC
+RUN: dsymutil --linker llvm -accelerator=Pub -f -o - -oso-prepend-path=%p/../.. %p/../../Inputs/basic-archive.macho.x86_64 | llvm-dwarfdump -a - | FileCheck %s --check-prefixes=CHECK,ARCHIVE
+RUN: dsymutil --linker llvm -accelerator=Pub -dump-debug-map -oso-prepend-path=%p/../.. %p/../../Inputs/basic.macho.x86_64 | dsymutil -accelerator=Pub -f -y -o - - | llvm-dwarfdump -a - | FileCheck %s --check-prefixes=CHECK,BASIC
+RUN: dsymutil --linker llvm -accelerator=Pub -dump-debug-map -oso-prepend-path=%p/../.. %p/../../Inputs/basic-archive.macho.x86_64 | dsymutil -accelerator=Pub -f -o - -y - | llvm-dwarfdump -a - | FileCheck %s --check-prefixes=CHECK,ARCHIVE
 
-#CHECK: LLVM parallel dwarflinker is not implemented yet.
+CHECK: file format Mach-O 64-bit x86-64
+
+CHECK: debug_info contents
+
+CHECK:  Compile Unit:
+
+CHECK:  DW_TAG_compile_unit
+CHECK:    DW_AT_producer ("Apple LLVM version 6.0 (clang-600.0.39) (based on LLVM 3.5svn)")
+CHECK:    DW_AT_language (DW_LANG_C99)
+CHECK:    DW_AT_name ("basic1.c")
+CHECK:    DW_AT_stmt_list (0x00000000)
+CHECK:    DW_AT_comp_dir ("/Inputs")
+CHECK:    DW_AT_low_pc (0x0000000100000ea0)
+CHECK:    DW_TAG_subprogram
+CHECK:    DW_AT_name ("main")
+CHECK:      DW_AT_decl_file ("/Inputs{{[/\\]}}basic1.c")
+CHECK:      DW_AT_decl_line (23)
+CHECK:      DW_AT_prototyped (0x01)
+CHECK:      DW_AT_type (0x00000063
+CHECK:      DW_AT_external (0x01)
+CHECK:      DW_AT_accessibility (DW_ACCESS_public)
+CHECK:      DW_AT_low_pc (0x0000000100000ea0)
+CHECK:      DW_AT_high_pc (0x0000000100000ec4)
+CHECK:      DW_AT_frame_base (DW_OP_reg6 RBP)
+CHECK:      DW_TAG_formal_parameter
+CHECK:        DW_AT_name ("argc")
+CHECK:        DW_AT_decl_file ("/Inputs{{[/\\]}}basic1.c")
+CHECK:        DW_AT_decl_line (23)
+CHECK:        DW_AT_type (0x00000063
+CHECK:        DW_AT_location (DW_OP_fbreg -8)
+CHECK:      DW_TAG_formal_parameter
+CHECK:        DW_AT_name ("argv")
+CHECK:        DW_AT_decl_file ("/Inputs{{[/\\]}}basic1.c")
+CHECK:        DW_AT_decl_line (23)
+CHECK:        DW_AT_type (0x0000006a
+CHECK:        DW_AT_location (DW_OP_fbreg -16)
+CHECK:      NULL
+CHECK:    DW_TAG_base_type
+CHECK:      DW_AT_name ("int")
+CHECK:      DW_AT_encoding (DW_ATE_signed)
+CHECK:      DW_AT_byte_size (0x04)
+CHECK:    DW_TAG_pointer_type
+CHECK:      DW_AT_type (0x0000006f
+CHECK:    DW_TAG_pointer_type
+CHECK:      DW_AT_type (0x00000074
+CHECK:    DW_TAG_const_type
+CHECK:      DW_AT_type (0x00000079
+CHECK:    DW_TAG_base_type
+CHECK:      DW_AT_name ("char")
+CHECK:      DW_AT_encoding (DW_ATE_signed_char)
+CHECK:      DW_AT_byte_size (0x01)
+CHECK:    NULL
+
+CHECK:  Compile Unit:
+
+CHECK:  DW_TAG_compile_unit
+CHECK:   DW_AT_producer ("Apple LLVM version 6.0 (clang-600.0.39) (based on LLVM 3.5svn)")
+CHECK:   DW_AT_name ("basic2.c")
+CHECK:   DW_AT_stmt_list (0x0000003f)
+CHECK:   DW_AT_comp_dir ("/Inputs")
+CHECK:   DW_AT_low_pc (0x0000000100000ed0)
+CHECK:    DW_TAG_base_type
+CHECK:      DW_AT_name ("int")
+CHECK:    DW_TAG_variable
+CHECK:      DW_AT_name ("private_int")
+CHECK:      DW_AT_type (0x000000a7
+CHECK:      DW_AT_decl_file ("/Inputs{{[/\\]}}basic2.c")
+BASIC:      DW_AT_location (DW_OP_addr 0x100001008)
+ARCHIVE:    DW_AT_location (DW_OP_addr 0x100001004)
+CHECK:    DW_TAG_variable
+CHECK:      DW_AT_name ("baz")
+CHECK:      DW_AT_type (0x000000a7
+CHECK:      DW_AT_decl_file ("/Inputs{{[/\\]}}basic2.c")
+CHECK:      DW_AT_location (DW_OP_addr 0x100001000)
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_name ("foo")
+CHECK:      DW_AT_decl_file ("/Inputs{{[/\\]}}basic2.c")
+CHECK:      DW_AT_type (0x000000a7
+CHECK:      DW_AT_low_pc (0x0000000100000ed0)
+CHECK:      DW_AT_high_pc (0x0000000100000f19)
+CHECK:      DW_AT_frame_base (DW_OP_reg6 RBP)
+CHECK:      DW_TAG_formal_parameter
+CHECK:        DW_AT_name ("arg")
+CHECK:        DW_AT_type (0x000000a7
+CHECK:        DW_AT_location (DW_OP_fbreg -4)
+CHECK:      NULL
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_name ("inc")
+CHECK:      DW_AT_type (0x000000a7
+CHECK:      DW_AT_low_pc (0x0000000100000f20)
+CHECK:      DW_AT_high_pc (0x0000000100000f37)
+CHECK:      DW_AT_frame_base (DW_OP_reg6 RBP)
+CHECK:    NULL
+
+CHECK:  Compile Unit:
+
+CHECK:  DW_TAG_compile_unit
+CHECK:    DW_AT_producer ("Apple LLVM version 6.0 (clang-600.0.39) (based on LLVM 3.5svn)")
+CHECK:    DW_AT_name ("basic3.c")
+CHECK:    DW_AT_stmt_list (0x00000093)
+CHECK:    DW_AT_comp_dir ("/Inputs")
+CHECK:    DW_AT_low_pc (0x0000000100000f40)
+CHECK:    DW_TAG_variable
+CHECK:      DW_AT_name ("val")
+CHECK:      DW_AT_type (0x00000162
+CHECK:      DW_AT_decl_file ("/Inputs{{[/\\]}}basic3.c")
+BASIC:      DW_AT_location (DW_OP_addr 0x100001004)
+ARCHIVE:    DW_AT_location (DW_OP_addr 0x100001008)
+CHECK:    DW_TAG_volatile_type
+CHECK:      DW_AT_type (0x00000167
+CHECK:    DW_TAG_base_type
+CHECK:      DW_AT_name ("int")
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_name ("bar")
+CHECK:      DW_AT_type (0x00000167
+CHECK:      DW_AT_low_pc (0x0000000100000f40)
+CHECK:      DW_AT_high_pc (0x0000000100000f84)
+CHECK:      DW_AT_frame_base (DW_OP_reg6 RBP)
+CHECK:      DW_TAG_formal_parameter
+CHECK:        DW_AT_name ("arg")
+CHECK:        DW_AT_type (0x00000167
+CHECK:        DW_AT_location (DW_OP_fbreg -8)
+CHECK:      NULL
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_name ("inc")
+CHECK:      DW_AT_type (0x00000167
+CHECK:      DW_AT_low_pc (0x0000000100000f90)
+CHECK:      DW_AT_high_pc (0x0000000100000fa9)
+CHECK:      DW_AT_frame_base (DW_OP_reg6 RBP)
+
+CHECK:    NULL
+
+CHECK-NOT: .debug_loc contents
+
+CHECK:.debug_aranges contents:
+CHECK-NEXT:Address Range Header: length = 0x0000002c, format = DWARF32, version = 0x0002, cu_offset = 0x00000000, addr_size = 0x08, seg_size = 0x00
+CHECK-NEXT:[0x0000000100000ea0, 0x0000000100000ec4)
+CHECK-NEXT:Address Range Header: length = 0x0000003c, format = DWARF32, version = 0x0002, cu_offset = 0x00000081, addr_size = 0x08, seg_size = 0x00
+CHECK-NEXT:[0x0000000100000ed0, 0x0000000100000f19)
+CHECK-NEXT:[0x0000000100000f20, 0x0000000100000f37)
+CHECK-NEXT:Address Range Header: length = 0x0000003c, format = DWARF32, version = 0x0002, cu_offset = 0x00000126, addr_size = 0x08, seg_size = 0x00
+CHECK-NEXT:[0x0000000100000f40, 0x0000000100000f84)
+CHECK-NEXT:[0x0000000100000f90, 0x0000000100000fa9)
+
+CHECK: .debug_line contents:
+CHECK: file_names[  1]:
+CHECK-NEXT: name: "basic1.c"
+CHECK-NEXT: dir_index: 0
+CHECK: Address            Line   Column File   ISA Discriminator OpIndex Flags
+CHECK-NEXT: ------------------ ------ ------ ------ --- ------------- ------- -------------
+CHECK-NEXT: 0x0000000100000ea0     23      0      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000eb6     24      0      1   0             0       0  is_stmt prologue_end
+CHECK-NEXT: 0x0000000100000ec4     24      0      1   0             0       0  is_stmt end_sequence
+
+CHECK: file_names[  1]:
+CHECK-NEXT: name: "basic2.c"
+CHECK-NEXT: dir_index: 0
+CHECK: Address            Line   Column File   ISA Discriminator OpIndex Flags
+CHECK-NEXT: ------------------ ------ ------ ------ --- ------------- ------- -------------
+CHECK-NEXT: 0x0000000100000ed0     19      0      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000ee2     20      0      1   0             0       0  is_stmt prologue_end
+CHECK-NEXT: 0x0000000100000f19     20      0      1   0             0       0  is_stmt end_sequence
+CHECK-NEXT: 0x0000000100000f20     14      0      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000f24     15      0      1   0             0       0  is_stmt prologue_end
+CHECK-NEXT: 0x0000000100000f37     15      0      1   0             0       0  is_stmt end_sequence
+
+CHECK: file_names[  1]:
+CHECK-NEXT: name: "basic3.c"
+CHECK-NEXT: dir_index: 0
+CHECK: Address            Line   Column File   ISA Discriminator OpIndex Flags
+CHECK-NEXT: ------------------ ------ ------ ------ --- ------------- ------- -------------
+CHECK-NEXT: 0x0000000100000f40     16      0      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000f4b     17      0      1   0             0       0  is_stmt prologue_end
+CHECK-NEXT: 0x0000000100000f58     18      0      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000f6c     19      0      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000f7b     20      0      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000f84     20      0      1   0             0       0  is_stmt end_sequence
+CHECK-NEXT: 0x0000000100000f90     11      0      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000f9b     12      0      1   0             0       0  is_stmt prologue_end
+CHECK-NEXT: 0x0000000100000fa9     12      0      1   0             0       0  is_stmt end_sequence

llvm/test/tools/dsymutil/X86/DWARFLinkerParallel/basic-lto-dw4-linking-x86.test

+RUN: dsymutil --linker llvm -f -o - -oso-prepend-path=%p/../.. %p/../../Inputs/basic-lto-dw4.macho.x86_64 | llvm-dwarfdump -a - | FileCheck %s
+
+CHECK: file format Mach-O 64-bit x86-64
+
+CHECK: debug_info contents
+
+CHECK:  Compile Unit: {{.*}} version = 0x0004
+CHECK:  DW_TAG_compile_unit
+CHECK:    DW_AT_producer ("clang version 3.7.0 ")
+CHECK:    DW_AT_language (DW_LANG_C99)
+CHECK:    DW_AT_name ("basic1.c")
+CHECK:    DW_AT_stmt_list (0x00000000)
+CHECK:    DW_AT_comp_dir ("/Inputs")
+CHECK:    DW_AT_low_pc (0x0000000100000f40)
+CHECK:    DW_AT_high_pc (0x0000000100000f4b)
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_low_pc (0x0000000100000f40)
+CHECK:      DW_AT_high_pc (0x0000000100000f4b)
+CHECK:      DW_AT_frame_base (DW_OP_reg6 RBP)
+CHECK:      DW_AT_name ("main")
+CHECK:      DW_AT_decl_file ("/Inputs{{[/\\]}}basic1.c")
+CHECK:      DW_AT_prototyped (true)
+CHECK:      DW_AT_type (0x00000000000000a1
+CHECK:      DW_AT_external (true)
+CHECK:      DW_TAG_formal_parameter
+CHECK:        DW_AT_location (DW_OP_reg5 RDI, DW_OP_piece 0x4)
+CHECK:        DW_AT_name ("argc")
+CHECK:        DW_AT_decl_file ("/Inputs{{[/\\]}}basic1.c")
+CHECK:        DW_AT_type (0x00000000000000a1
+CHECK:      DW_TAG_formal_parameter
+CHECK:        DW_AT_location (DW_OP_reg4 RSI)
+CHECK:        DW_AT_name ("argv")
+CHECK:        DW_AT_type (0x00000060
+CHECK:      NULL
+CHECK:    DW_TAG_pointer_type
+CHECK:       DW_AT_type (0x00000065
+CHECK:    DW_TAG_pointer_type
+CHECK:    DW_TAG_const_type
+CHECK:    DW_TAG_base_type
+CHECK:      DW_AT_name ("char")
+CHECK:      DW_AT_encoding (DW_ATE_signed_char)
+CHECK:      DW_AT_byte_size (0x01)
+CHECK:    NULL
+
+CHECK:  Compile Unit:{{.*}} version = 0x0004
+
+CHECK:  DW_TAG_compile_unit
+CHECK:    DW_AT_producer ("clang version 3.7.0 ")
+CHECK:    DW_AT_language (DW_LANG_C99)
+CHECK:    DW_AT_name ("basic2.c")
+CHECK:    DW_AT_stmt_list (0x00000044)
+CHECK:    DW_AT_low_pc (0x0000000100000f50)
+CHECK:    DW_AT_high_pc (0x0000000100000f87)
+CHECK:    DW_TAG_base_type
+CHECK:      DW_AT_name ("int")
+CHECK:    DW_TAG_variable
+CHECK:      DW_AT_name ("baz")
+CHECK:      DW_AT_location (DW_OP_addr 0x100001000)
+CHECK:    DW_TAG_variable
+CHECK:      DW_AT_name ("private_int")
+CHECK:      DW_AT_decl_file ("/Inputs{{[/\\]}}basic2.c")
+CHECK:      DW_AT_location (DW_OP_addr 0x100001008)
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_name ("inc")
+CHECK:      DW_AT_type (0x000000a1
+CHECK:      DW_AT_inline (DW_INL_inlined)
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_low_pc (0x0000000100000f50)
+CHECK:      DW_AT_high_pc (0x0000000100000f87)
+CHECK:      DW_AT_frame_base (DW_OP_reg6 RBP)
+CHECK:      DW_AT_name ("foo")
+CHECK:      DW_AT_decl_file ("/Inputs{{[/\\]}}basic2.c")
+CHECK:      DW_AT_prototyped (true)
+CHECK:      DW_AT_type (0x000000a1
+CHECK:      DW_TAG_formal_parameter
+CHECK:        DW_AT_location (0x00000000
+CHECK:          [0x0000000100000f50, 0x0000000100000f5c): DW_OP_reg5 RDI, DW_OP_piece 0x4)
+CHECK:        DW_AT_name ("arg")
+CHECK:        DW_AT_type (0x000000a1
+CHECK:      DW_TAG_inlined_subroutine
+CHECK:        DW_AT_abstract_origin (0x000000d2 "inc")
+CHECK:        DW_AT_low_pc (0x0000000100000f61)
+CHECK:        DW_AT_high_pc (0x0000000100000f70)
+CHECK:      NULL
+CHECK:    NULL
+
+CHECK:  Compile Unit: {{.*}} version = 0x0004
+
+CHECK:  DW_TAG_compile_unit
+CHECK:    DW_AT_producer ("clang version 3.7.0 ")
+CHECK:    DW_AT_name ("basic3.c")
+CHECK:    DW_AT_stmt_list (0x0000009a)
+CHECK:    DW_AT_low_pc (0x0000000100000f90)
+CHECK:    DW_AT_high_pc (0x0000000100000fb4)
+CHECK:    DW_TAG_variable
+CHECK:      DW_AT_name ("val")
+CHECK:      DW_AT_decl_file ("/Inputs{{[/\\]}}basic3.c")
+CHECK:      DW_AT_location (DW_OP_addr 0x100001004)
+CHECK:    DW_TAG_volatile_type
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_name ("inc")
+CHECK:      DW_AT_inline (DW_INL_inlined)
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_low_pc (0x0000000100000f90)
+CHECK:      DW_AT_high_pc (0x0000000100000fb4)
+CHECK:      DW_AT_frame_base (DW_OP_reg6 RBP)
+CHECK:      DW_AT_name ("bar")
+CHECK:      DW_TAG_formal_parameter
+CHECK:        DW_AT_location (0x00000025
+CHECK:          [0x0000000100000f90, 0x0000000100000f9f): DW_OP_reg5 RDI, DW_OP_piece 0x4
+CHECK:          [0x0000000100000fa9, 0x0000000100000fad): DW_OP_reg5 RDI, DW_OP_piece 0x4)
+CHECK:        DW_AT_name ("arg")
+CHECK:      DW_TAG_inlined_subroutine
+CHECK:        DW_AT_abstract_origin (0x0000015f "inc")
+CHECK:        DW_AT_ranges (0x00000000
+CHECK:           [0x0000000100000f94, 0x0000000100000f9a)
+CHECK:           [0x0000000100000f9f, 0x0000000100000fa7))
+
+CHECK:      NULL
+CHECK:    NULL
+
+
+CHECK: .debug_loc contents:
+CHECK-NEXT: 0x00000000:
+CHECK-NEXT:              (0x0000000000000000, 0x000000000000000c): DW_OP_reg5 RDI, DW_OP_piece 0x4
+CHECK-NOT: :
+CHECK:      0x00000025:
+CHECK-NEXT:              (0x0000000000000000, 0x000000000000000f): DW_OP_reg5 RDI, DW_OP_piece 0x4
+CHECK-NEXT:              (0x0000000000000019, 0x000000000000001d): DW_OP_reg5 RDI, DW_OP_piece 0x4
+
+
+CHECK: .debug_aranges contents:
+CHECK-NEXT: Address Range Header: length = 0x0000002c, format = DWARF32, version = 0x0002, cu_offset = 0x00000000, addr_size = 0x08, seg_size = 0x00
+CHECK-NEXT: [0x0000000100000f40,  0x0000000100000f4b)
+CHECK-NEXT: Address Range Header: length = 0x0000002c, format = DWARF32, version = 0x0002, cu_offset = 0x00000077, addr_size = 0x08, seg_size = 0x00
+CHECK-NEXT: [0x0000000100000f50, 0x0000000100000f87)
+CHECK-NEXT: Address Range Header: length = 0x0000002c, format = DWARF32, version = 0x0002, cu_offset = 0x0000011b, addr_size = 0x08, seg_size = 0x00
+CHECK-NEXT: [0x0000000100000f90, 0x0000000100000fb4)
+
+CHECK: .debug_line contents:
+CHECK: file_names[  1]:
+CHECK-NEXT: name: "basic1.c"
+CHECK-NEXT: dir_index: 0
+CHECK: Address            Line   Column File   ISA Discriminator OpIndex Flags
+CHECK-NEXT: ------------------ ------ ------ ------ --- ------------- ------- -------------
+CHECK-NEXT: 0x0000000100000f40     26      0      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000f44     27     10      1   0             0       0  is_stmt prologue_end
+CHECK-NEXT: 0x0000000100000f49     27      3      1   0             0       0
+CHECK-NEXT: 0x0000000100000f4b     27      3      1   0             0       0  end_sequence
+
+CHECK: file_names[  1]:
+CHECK-NEXT: name: "basic2.c"
+CHECK-NEXT: dir_index: 0
+CHECK: Address            Line   Column File   ISA Discriminator OpIndex Flags
+CHECK-NEXT: ------------------ ------ ------ ------ --- ------------- ------- -------------
+CHECK-NEXT: 0x0000000100000f50     19      0      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000f54     20     18      1   0             0       0  is_stmt prologue_end
+CHECK-NEXT: 0x0000000100000f5a     20     17      1   0             0       0
+CHECK-NEXT: 0x0000000100000f5c     20     10      1   0             0       0
+CHECK-NEXT: 0x0000000100000f61     15     10      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000f70     20     23      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000f74     20     36      1   0             0       0
+CHECK-NEXT: 0x0000000100000f83     20     31      1   0             0       0
+CHECK-NEXT: 0x0000000100000f85     20      3      1   0             0       0
+CHECK-NEXT: 0x0000000100000f87     20      3      1   0             0       0  end_sequence
+
+CHECK: file_names[  1]:
+CHECK-NEXT: name: "basic3.c"
+CHECK-NEXT: dir_index: 0
+CHECK: Address            Line   Column File   ISA Discriminator OpIndex Flags
+CHECK-NEXT: ------------------ ------ ------ ------ --- ------------- ------- -------------
+CHECK-NEXT: 0x0000000100000f90     16      0      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000f94     12     10      1   0             0       0  is_stmt prologue_end
+CHECK-NEXT: 0x0000000100000f9a     17      7      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000f9f     12     10      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000fa7     20      1      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000fa9     19     18      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000fab     19     10      1   0             0       0
+CHECK-NEXT: 0x0000000100000fb2     20      1      1   0             0       0  is_stmt
+CHECK-NEXT: 0x0000000100000fb4     20      1      1   0             0       0  is_stmt end_sequence
+
+CHECK-NOT: .debug_pubnames contents:
+CHECK-NOT: .debug_pubtypes contents:

llvm/test/tools/dsymutil/X86/DWARFLinkerParallel/basic-lto-linking-x86.test

+RUN: dsymutil --linker llvm -f -o - -oso-prepend-path=%p/../.. %p/../../Inputs/basic-lto.macho.x86_64 | llvm-dwarfdump -a - | FileCheck %s
+RUN: dsymutil --linker llvm -oso-prepend-path=%p/../.. -dump-debug-map %p/../../Inputs/basic-lto.macho.x86_64 | dsymutil -f -o - -y - | llvm-dwarfdump -a - | FileCheck %s
+
+CHECK: file format Mach-O 64-bit x86-64
+
+CHECK: debug_info contents
+
+CHECK:  Compile Unit:
+
+CHECK:  DW_TAG_compile_unit
+CHECK:    DW_AT_producer ("Apple LLVM version 6.0 (clang-600.0.39) (based on LLVM 3.5svn)")
+CHECK:    DW_AT_language (DW_LANG_C99)
+CHECK:    DW_AT_name ("basic1.c")
+CHECK:    DW_AT_stmt_list (0x00000000)
+CHECK:    DW_AT_comp_dir ("/Inputs")
+CHECK:    DW_AT_low_pc (0x0000000100000f40)
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_name ("main")
+CHECK:      DW_AT_decl_file ("/Inputs{{[/\\]}}basic1.c")
+CHECK:      DW_AT_decl_line (23)
+CHECK:      DW_AT_prototyped (0x01)
+CHECK:      DW_AT_type (0x00000063
+CHECK:      DW_AT_external (0x01)
+CHECK:      DW_AT_accessibility (DW_ACCESS_public)
+CHECK:      DW_AT_low_pc (0x0000000100000f40)
+CHECK:      DW_AT_high_pc (0x0000000100000f4b)
+CHECK:      DW_AT_frame_base (DW_OP_reg6 RBP)
+CHECK:      DW_TAG_formal_parameter
+CHECK:        DW_AT_name ("argc")
+CHECK:        DW_AT_type (0x00000063
+CHECK:        DW_AT_location (DW_OP_reg5 RDI, DW_OP_piece 0x4)
+CHECK:      DW_TAG_formal_parameter
+CHECK:        DW_AT_name ("argv")
+CHECK:        DW_AT_type (0x0000006a
+CHECK:        DW_AT_location (DW_OP_reg4 RSI)
+CHECK:      NULL
+CHECK:    DW_TAG_base_type
+CHECK:      DW_AT_name ("int")
+CHECK:      DW_AT_encoding (DW_ATE_signed)
+CHECK:      DW_AT_byte_size (0x04)
+CHECK:    DW_TAG_pointer_type
+CHECK:      DW_AT_type (0x0000006f
+CHECK:    DW_TAG_pointer_type
+CHECK:      DW_AT_type (0x00000074
+CHECK:    DW_TAG_const_type
+CHECK:      DW_AT_type (0x00000079
+CHECK:    DW_TAG_base_type
+CHECK:      DW_AT_name ("char")
+CHECK:      DW_AT_encoding (DW_ATE_signed_char)
+CHECK:      DW_AT_byte_size (0x01)
+CHECK:    NULL
+
+CHECK:  Compile Unit:
+
+CHECK:  DW_TAG_compile_unit
+CHECK:    DW_AT_producer ("Apple LLVM version 6.0 (clang-600.0.39) (based on LLVM 3.5svn)")
+CHECK:    DW_AT_name ("basic2.c")
+CHECK:    DW_AT_stmt_list (0x0000003e)
+CHECK:    DW_AT_comp_dir ("/Inputs")
+CHECK:   DW_AT_low_pc (0x0000000100000f50)
+CHECK:    DW_TAG_variable
+CHECK:      DW_AT_name ("private_int")
+CHECK:      DW_AT_type (0x0000000000000063
+CHECK:      DW_AT_decl_file ("/Inputs{{[/\\]}}basic2.c")
+CHECK:      DW_AT_location (DW_OP_addr 0x100001008)
+CHECK:    DW_TAG_variable
+CHECK:      DW_AT_name ("baz")
+CHECK:      DW_AT_type (0x0000000000000063
+CHECK:      DW_AT_location (DW_OP_addr 0x100001000)
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_name ("foo")
+CHECK:      DW_AT_type (0x0000000000000063
+CHECK:      DW_AT_low_pc (0x0000000100000f50)
+CHECK:      DW_AT_high_pc (0x0000000100000f89)
+CHECK:      DW_AT_frame_base (DW_OP_reg6 RBP)
+CHECK:      DW_TAG_formal_parameter
+CHECK:        DW_AT_name ("arg")
+CHECK:        DW_AT_type (0x0000000000000063
+CHECK:        DW_AT_location (0x00000000
+CHECK:          [0x0000000100000f50, 0x0000000100000f5e): DW_OP_reg5 RDI, DW_OP_piece 0x4)
+CHECK:[[INC1:0x[0-9a-f]*]]{{.*}}DW_TAG_inlined_subroutine
+CHECK:        DW_AT_abstract_origin (0x00000128 "inc")
+CHECK:        DW_AT_low_pc (0x0000000100000f63)
+CHECK:        DW_AT_high_pc (0x0000000100000f72)
+CHECK:        DW_AT_call_line (20)
+CHECK:      NULL
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_name ("inc")
+CHECK:      DW_AT_type (0x0000000000000063
+CHECK:      DW_AT_inline (DW_INL_inlined)
+CHECK:    NULL
+
+CHECK:  Compile Unit:
+
+CHECK:  DW_TAG_compile_unit
+CHECK:    DW_AT_producer ("Apple LLVM version 6.0 (clang-600.0.39) (based on LLVM 3.5svn)")
+CHECK:    DW_AT_name ("basic3.c")
+CHECK:    DW_AT_stmt_list (0x0000007e)
+CHECK:    DW_AT_comp_dir ("/Inputs")
+CHECK:    DW_AT_low_pc (0x0000000100000f90)
+CHECK:    DW_TAG_variable
+CHECK:      DW_AT_name ("val")
+CHECK:      DW_AT_type (0x00000176
+CHECK:      DW_AT_decl_file ("/Inputs{{[/\\]}}basic3.c")
+CHECK:      DW_AT_location (DW_OP_addr 0x100001004)
+CHECK:    DW_TAG_volatile_type
+CHECK:      DW_AT_type (0x0000000000000063
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_name ("bar")
+CHECK:      DW_AT_type (0x0000000000000063
+CHECK:      DW_AT_low_pc (0x0000000100000f90)
+CHECK:      DW_AT_high_pc (0x0000000100000fb4)
+CHECK:      DW_AT_frame_base (DW_OP_reg6 RBP)
+CHECK:      DW_TAG_formal_parameter
+CHECK:        DW_AT_name ("arg")
+CHECK:        DW_AT_type (0x0000000000000063
+CHECK:        DW_AT_location (0x00000025
+CHECK:          [0x0000000100000f90, 0x0000000100000f9f): DW_OP_reg5 RDI, DW_OP_piece 0x4
+CHECK:          [0x0000000100000fa9, 0x0000000100000fad): DW_OP_reg5 RDI, DW_OP_piece 0x4)
+CHECK:      DW_TAG_lexical_block
+CHECK:        DW_AT_low_pc (0x0000000100000f94)
+CHECK:        DW_AT_high_pc (0x0000000100000fa7)
+CHECK:[[INC2:0x[0-9a-f]*]]{{.*}}DW_TAG_inlined_subroutine
+CHECK:          DW_AT_abstract_origin (0x000001d4 "inc")
+CHECK:          DW_AT_ranges (0x00000000
+CHECK:             [0x0000000100000f94, 0x0000000100000f9a)
+CHECK:             [0x0000000100000f9f, 0x0000000100000fa7))
+CHECK:        NULL
+CHECK:      NULL
+CHECK:    DW_TAG_subprogram
+CHECK:      DW_AT_name ("inc")
+CHECK:      DW_AT_type (0x0000000000000063
+CHECK:    NULL
+
+CHECK: .debug_loc contents:
+CHECK-NEXT: 0x00000000:
+CHECK-NEXT:              (0x0000000000000000, 0x000000000000000e): DW_OP_reg5 RDI, DW_OP_piece 0x4
+CHECK-NOT: :
+CHECK:      0x00000025:
+CHECK-NEXT:              (0x0000000000000000, 0x000000000000000f): DW_OP_reg5 RDI, DW_OP_piece 0x4
+CHECK-NEXT:              (0x0000000000000019, 0x000000000000001d): DW_OP_reg5 RDI, DW_OP_piece 0x4
+
+CHECK: .debug_aranges contents:
+CHECK-NEXT: Address Range Header: length = 0x0000002c, format = DWARF32, version = 0x0002, cu_offset = 0x00000000, addr_size = 0x08, seg_size = 0x00
+CHECK-NEXT: [0x0000000100000f40, 0x0000000100000f4b)
+CHECK-NEXT: Address Range Header: length = 0x0000002c, format = DWARF32, version = 0x0002, cu_offset = 0x00000081, addr_size = 0x08, seg_size = 0x00
+CHECK-NEXT: [0x0000000100000f50, 0x0000000100000f89)
+CHECK-NEXT: Address Range Header: length = 0x0000002c, format = DWARF32, version = 0x0002, cu_offset = 0x0000013a, addr_size = 0x08, seg_size = 0x00
+CHECK-NEXT: [0x0000000100000f90, 0x0000000100000fb4)
+
+
+CHECK: .debug_line contents
+CHECK: file_names[  1]:
+CHECK-NEXT: name: "basic1.c"
+CHECK-NEXT: dir_index: 0
+CHECK: 0x0000000100000f40     23      0      1   0             0       0  is_stmt
+CHECK: 0x0000000100000f44     24      0      1   0             0       0  is_stmt prologue_end
+CHECK: 0x0000000100000f4b     24      0      1   0             0       0  is_stmt end_sequence
+
+CHECK: file_names[  1]:
+CHECK-NEXT: name: "basic2.c"
+CHECK-NEXT: dir_index: 0
+CHECK: 0x0000000100000f50     19      0      1   0             0       0  is_stmt
+CHECK: 0x0000000100000f54     20      0      1   0             0       0  is_stmt prologue_end
+CHECK: 0x0000000100000f63     15      0      1   0             0       0  is_stmt
+CHECK: 0x0000000100000f72     20      0      1   0             0       0  is_stmt
+CHECK: 0x0000000100000f89     20      0      1   0             0       0  is_stmt end_sequence
+
+CHECK: file_names[  1]:
+CHECK-NEXT: name: "basic3.c"
+CHECK-NEXT: dir_index: 0
+CHECK: 0x0000000100000f90     16      0      1   0             0       0  is_stmt
+CHECK: 0x0000000100000f94     12      0      1   0             0       0  is_stmt prologue_end
+CHECK: 0x0000000100000f9a     17      0      1   0             0       0  is_stmt
+CHECK: 0x0000000100000f9f     12      0      1   0             0       0  is_stmt
+CHECK: 0x0000000100000fa7     20      0      1   0             0       0  is_stmt
+CHECK: 0x0000000100000fa9     19      0      1   0             0       0  is_stmt
+CHECK: 0x0000000100000fb2     20      0      1   0             0       0  is_stmt
+CHECK: 0x0000000100000fb4     20      0      1   0             0       0  is_stmt end_sequence
+
+CHECK-NOT: .debug_pubnames contents:
+CHECK-NOT: .debug_pubtypes contents:

llvm/test/tools/dsymutil/X86/DWARFLinkerParallel/basic-with-libfat-test.test

+RUN: cat %p/../../Inputs/basic-with-libfat-test.macho.x86_64 > %t1
+RUN: dsymutil --linker llvm -f -oso-prepend-path=%p/../.. %t1
+RUN: llvm-dwarfdump %t1.dwarf | FileCheck %s
+
+The test binary was created by force-linking the libfat-test.a fat archive
+with the basic linking test archive, like so:
+$ clang -all_load libfat-test.a libbasic.a basic1.macho.x86_64.o -Wl,-dead_strip -u _x86_64_var
+
+CHECK: DW_AT_name{{.*}}"x86_64_var"
+CHECK: DW_AT_name{{.*}}"basic2.c"
+CHECK: DW_AT_name{{.*}}"basic3.c"
+CHECK: DW_AT_name{{.*}}"basic1.c"

llvm/test/tools/dsymutil/X86/DWARFLinkerParallel/empty_range.s

+# This test verifies that an empty range list in the .debug_ranges section
+# doesn't crash dsymutil. As clang does not produce this kind of debug
+# info anymore, we used this hand-crafted assembly file to produce a testcase
+# Compile with:
+#        llvm-mc -triple x86_64-apple-darwin -filetype=obj -o 1.o empty_range.o
+
+# RUN: dsymutil --linker llvm -f -y %p/../dummy-debug-map.map -oso-prepend-path %p/../../Inputs/empty_range -o - | llvm-dwarfdump -debug-info - | FileCheck %s
+
+        .section  __TEXT,__text,regular,pure_instructions
+  .macosx_version_min 10, 11
+  .globl  __Z3foov
+  .align  4, 0x90
+__Z3foov:                               ## @_Z3foov
+Lfunc_begin0:
+  pushq %rbp
+  movq  %rsp, %rbp
+  popq  %rbp
+  retq
+Lfunc_end0:
+  .section  __DWARF,__debug_abbrev,regular,debug
+Lsection_abbrev:
+  .byte 1                       ## Abbreviation Code
+  .byte 17                      ## DW_TAG_compile_unit
+  .byte 1                       ## DW_CHILDREN_yes
+  .byte 0                       ## EOM(1)
+  .byte 0                       ## EOM(2)
+  .byte 2                       ## Abbreviation Code
+  .byte 46                      ## DW_TAG_subprogram
+  .byte 0                       ## DW_CHILDREN_no
+  .byte 17                      ## DW_AT_low_pc
+  .byte 1                       ## DW_FORM_addr
+        .byte   0x55                    ## DW_AT_ranges
+        .byte   6                       ## DW_FORM_data4
+  .byte 0                       ## EOM(1)
+  .byte 0                       ## EOM(2)
+  .byte 0                       ## EOM(3)
+  .section  __DWARF,__debug_info,regular,debug
+Lsection_info:
+  .long 22                      ## Length of Unit
+  .short  2                       ## DWARF version number
+  .long 0                       ## Offset Into Abbrev. Section
+  .byte 8                       ## Address Size (in bytes)
+  .byte 1                       ## Abbrev [1]  DW_TAG_compile_unit
+  .byte 2                       ## Abbrev [2] DW_TAG_subprogram
+  .quad Lfunc_begin0            ## DW_AT_low_pc
+        .long   0                       ## DW_AT_ranges (pointing at an empty entry)
+  .byte 0                       ## End Of Children Mark
+  .section  __DWARF,__debug_ranges,regular,debug
+Ldebug_range:
+        .long 0
+        .long 0
+
+# CHECK-NOT:  DW_TAG_compile_unit

llvm/test/tools/dsymutil/X86/DWARFLinkerParallel/frame-1.test

+# RUN: rm -rf %t
+# RUN: mkdir -p %t
+# RUN: llc -filetype=obj %p/../../Inputs/frame-dw2.ll -o %t/frame-dw2.o
+# RUN: dsymutil --linker llvm -f -oso-prepend-path=%t -y %s -o - | \
+# RUN:   llvm-dwarfdump -debug-frame - | FileCheck %s
+
+# This test is meant to verify that identical CIEs will get reused
+# in the same file but not inbetween files. For this to happen, we
+# link twice the same file using this made-up debug map:
+
+---
+triple:          'i386-apple-darwin'
+objects:
+  - filename: frame-dw2.o
+    symbols:
+      - { sym: _bar, objAddr: 0x0, binAddr: 0x1000, size: 0x12 }
+      - { sym: _baz, objAddr: 0x0, binAddr: 0x2000, size: 0x12 }
+  - filename: frame-dw2.o
+    symbols:
+      - { sym: _bar, objAddr: 0x0, binAddr: 0x3000, size: 0x12 }
+      - { sym: _baz, objAddr: 0x0, binAddr: 0x4000, size: 0x12 }
+...
+
+# CHECK: .debug_frame contents:
+# CHECK: 00000000 {{[0-9a-f]*}} ffffffff CIE
+# CHECK-NOT: FDE
+# CHECK:  FDE cie=00000000 pc=00001000...00001
+# CHECK-NOT: FDE
+# CHECK:  FDE cie=00000000 pc=00002000...00002
+# CHECK:  [[CIECU2:[0-9a-f]*]] {{[0-9a-f]*}} ffffffff CIE
+# CHECK-NOT: FDE
+# CHECK:  FDE cie=[[CIECU2]] pc=00003000...00003
+# CHECK-NOT: FDE
+# CHECK:  FDE cie=[[CIECU2]] pc=00004000...00004
+# CHECK-NOT: FDE
+# CHECK: .eh_frame contents:

llvm/test/tools/dsymutil/X86/DWARFLinkerParallel/frame-2.test

+# RUN: rm -rf %t
+# RUN: mkdir -p %t
+# RUN: llc -filetype=obj %p/../../Inputs/frame-dw2.ll -o %t/frame-dw2.o
+# RUN: llc -filetype=obj %p/../../Inputs/frame-dw4.ll -o %t/frame-dw4.o
+# RUN: dsymutil --linker llvm -f -oso-prepend-path=%t -y %s -o - | \
+# RUN:   llvm-dwarfdump -debug-frame - | FileCheck %s
+
+# Check the handling of multiple different CIEs. To have CIEs that
+# appear to be different, use a dwarf2 version of the file along with
+# a dwarf 4 version. The CIE header version (and layout) will be different.
+---
+triple:          'i386-apple-darwin'
+objects:
+  - filename: frame-dw2.o
+    symbols:
+      - { sym: _bar, objAddr: 0x0, binAddr: 0x1000, size: 0x12 }
+      - { sym: _baz, objAddr: 0x0, binAddr: 0x2000, size: 0x12 }
+  - filename: frame-dw4.o
+    symbols:
+      - { sym: _baz, objAddr: 0x0, binAddr: 0x3000, size: 0x12 }
+  - filename: frame-dw2.o
+    symbols:
+      - { sym: _bar, objAddr: 0x0, binAddr: 0x4000, size: 0x12 }
+...
+
+# CHECK: .debug_frame contents:
+# CHECK: 00000000 {{[0-9a-f]*}} ffffffff CIE
+# CHECK-NEXT: Format: DWARF32
+# CHECK-NEXT: Version:{{.*}}1
+# CHECK-NOT: FDE
+# CHECK:  FDE cie=00000000 pc=00001000...00001
+# CHECK-NOT: FDE
+# CHECK:  FDE cie=00000000 pc=00002000...00002
+# CHECK-NOT: FDE
+# CHECK: [[CIEDW4:[0-9a-f]*]] 00000010 ffffffff CIE
+# CHECK-NEXT: Format: DWARF32
+# CHECK-NEXT: Version:{{.*}}4
+# CHECK-NOT: FDE
+# CHECK:  FDE cie=[[CIEDW4]] pc=00003000...00003
+# CHECK: [[CIEDW1_2:[0-9a-f]*]] 00000010 ffffffff CIE
+# CHECK-NEXT: Format: DWARF32
+# CHECK-NEXT: Version:{{.*}}1
+# CHECK-NOT: FDE
+# CHECK:  FDE cie=[[CIEDW1_2]] pc=00004000...00004
+# CHECK-NOT: FDE
+# CHECK: .eh_frame contents:

llvm/test/tools/dsymutil/X86/DWARFLinkerParallel/multiple-inputs.test

 RUN: rm -rf %t
 RUN: mkdir -p %t
 
-RUN: cat %p/../Inputs/basic.macho.x86_64 > %t/basic.macho.x86_64
-RUN: cat %p/../Inputs/basic-archive.macho.x86_64 > %t/basic-archive.macho.x86_64
-RUN: cat %p/../Inputs/basic-lto.macho.x86_64 > %t/basic-lto.macho.x86_64
-RUN: cat %p/../Inputs/basic-lto-dw4.macho.x86_64 > %t/basic-lto-dw4.macho.x86_64
+RUN: cat %p/../../Inputs/basic.macho.x86_64 > %t/basic.macho.x86_64
+RUN: cat %p/../../Inputs/basic-archive.macho.x86_64 > %t/basic-archive.macho.x86_64
+RUN: cat %p/../../Inputs/basic-lto.macho.x86_64 > %t/basic-lto.macho.x86_64
+RUN: cat %p/../../Inputs/basic-lto-dw4.macho.x86_64 > %t/basic-lto-dw4.macho.x86_64
 
 # Multiple inputs in flat mode
-RUN: dsymutil -f -oso-prepend-path=%p/.. %t/basic.macho.x86_64 %t/basic-archive.macho.x86_64 %t/basic-lto.macho.x86_64 %t/basic-lto-dw4.macho.x86_64
+RUN: dsymutil --linker llvm -f -oso-prepend-path=%p/../.. %t/basic.macho.x86_64 %t/basic-archive.macho.x86_64 %t/basic-lto.macho.x86_64 %t/basic-lto-dw4.macho.x86_64
 RUN: llvm-dwarfdump -a %t/basic.macho.x86_64.dwarf \
 RUN: | FileCheck %S/basic-linking-x86.test --check-prefixes=CHECK,BASIC
 RUN: llvm-dwarfdump -a %t/basic-archive.macho.x86_64.dwarf \
 RUN: | FileCheck %S/basic-linking-x86.test --check-prefixes=CHECK,ARCHIVE
 RUN: llvm-dwarfdump -a %t/basic-lto.macho.x86_64.dwarf | FileCheck %S/basic-lto-linking-x86.test
 RUN: llvm-dwarfdump -a %t/basic-lto-dw4.macho.x86_64.dwarf | FileCheck %S/basic-lto-dw4-linking-x86.test
 
 # Multiple inputs that end up in the same named bundle
-RUN: dsymutil -oso-prepend-path=%p/.. %t/basic.macho.x86_64 %t/basic-archive.macho.x86_64 %t/basic-lto.macho.x86_64 %t/basic-lto-dw4.macho.x86_64 -o %t.dSYM
+RUN: dsymutil --linker llvm -oso-prepend-path=%p/../.. %t/basic.macho.x86_64 %t/basic-archive.macho.x86_64 %t/basic-lto.macho.x86_64 %t/basic-lto-dw4.macho.x86_64 -o %t.dSYM
 RUN: llvm-dwarfdump -a %t.dSYM/Contents/Resources/DWARF/basic.macho.x86_64 \
 RUN: | FileCheck %S/basic-linking-x86.test --check-prefixes=CHECK,BASIC
 RUN: llvm-dwarfdump -a %t.dSYM/Contents/Resources/DWARF/basic-archive.macho.x86_64 \
 RUN: | FileCheck %S/basic-linking-x86.test --check-prefixes=CHECK,ARCHIVE
 RUN: llvm-dwarfdump -a %t.dSYM/Contents/Resources/DWARF/basic-lto.macho.x86_64 | FileCheck %S/basic-lto-linking-x86.test
 RUN: llvm-dwarfdump -a %t.dSYM/Contents/Resources/DWARF/basic-lto-dw4.macho.x86_64 | FileCheck %S/basic-lto-dw4-linking-x86.test
 
 # Multiple inputs in a named bundle in flat mode... impossible.
-RUN: not dsymutil -f -oso-prepend-path=%p/.. %t/basic.macho.x86_64 %t/basic-archive.macho.x86_64 %t/basic-lto.macho.x86_64 %t/basic-lto-dw4.macho.x86_64 -o %t.dSYM 2>&1 | FileCheck %s
+RUN: not dsymutil --linker llvm -f -oso-prepend-path=%p/../.. %t/basic.macho.x86_64 %t/basic-archive.macho.x86_64 %t/basic-lto.macho.x86_64 %t/basic-lto-dw4.macho.x86_64 -o %t.dSYM 2>&1 | FileCheck %s
 
 CHECK: error: cannot use -o with multiple inputs in flat mode
-

llvm/test/tools/dsymutil/X86/alias.test

 # RUN: dsymutil -f -oso-prepend-path=%p/../Inputs/alias \
 # RUN: %p/../Inputs/alias/foobar -o - | llvm-dwarfdump - 2>&1 | FileCheck %s
+
+# RUN: dsymutil --linker llvm -f -oso-prepend-path=%p/../Inputs/alias \
+# RUN: %p/../Inputs/alias/foobar -o - | llvm-dwarfdump - 2>&1 | FileCheck %s
+
 # CHECK-NOT: could not find object file symbol for symbol
 # CHECK: DW_AT_name ("foo.c")
 # CHECK: DW_AT_name ("bar.c")
 
 # Source:
 #   $ cat foo.c
 #   int foo = 1;
 #   $ cat bar.c

llvm/test/tools/dsymutil/X86/call-site-entry-linking.test

 RUN: dsymutil -oso-prepend-path=%p %p/Inputs/call-site-entry.macho.x86_64 -o %t.dSYM
 RUN: llvm-dwarfdump %t.dSYM | FileCheck %s -implicit-check-not=DW_AT_call_return_pc
 
+RUN: dsymutil --linker llvm -oso-prepend-path=%p %p/Inputs/call-site-entry.macho.x86_64 -o %t.dSYM
+RUN: llvm-dwarfdump %t.dSYM | FileCheck %s -implicit-check-not=DW_AT_call_return_pc
+
 CHECK: DW_AT_call_return_pc  (0x0000000100000fa4)

llvm/test/tools/dsymutil/X86/call-site-entry-reloc.test

 
 The test requires the return PC to match a relocation (in this case the
 DW_AT_high_pc of main). Without this change the value would get relocated
 twice.
 
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/call_return_pc/call -o %t.dSYM
 RUN: llvm-dwarfdump %t.dSYM | FileCheck %s -implicit-check-not=DW_AT_call_return_pc
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/call_return_pc/call -o %t.dSYM
+RUN: llvm-dwarfdump %t.dSYM | FileCheck %s -implicit-check-not=DW_AT_call_return_pc
+
 CHECK: DW_AT_call_return_pc  (0x0000000100000f72)
 CHECK: DW_AT_call_return_pc  (0x0000000100000f78)

llvm/test/tools/dsymutil/X86/common-sym-multi.test

 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/common/common.x86_64 -f -o - | llvm-dwarfdump -debug-info - | FileCheck %s
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/common/common.x86_64 -dump-debug-map | FileCheck %s --check-prefix DEBUGMAP
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/common/common.x86_64 -f -o - | llvm-dwarfdump -debug-info - | FileCheck %s
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/common/common.x86_64 -dump-debug-map | FileCheck %s --check-prefix DEBUGMAP
+
 The test was compiled from two source files:
 $ cd /private/tmp/common
 $ cat common1.c
 int i[1000];
 int main() {
   return i[1];
 }
 $ cat common2.c

llvm/test/tools/dsymutil/X86/common-sym.test

 RUN: dsymutil -oso-prepend-path %p/.. %p/../Inputs/common.macho.x86_64 -f -o - | llvm-dwarfdump -v -debug-info - | FileCheck %s
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/.. %p/../Inputs/common.macho.x86_64 -f -o - | llvm-dwarfdump -v -debug-info - | FileCheck %s
+
 The test was compiled from a single source:
 $ cat common.c 
 char common[16];
 int main() { return 0;}
 void bar() {}
 $ clang -g -c common.c -o common.macho.x86_64.o
 $ clang common.macho.x86_64.o -o common.macho.x86_64
 

llvm/test/tools/dsymutil/X86/custom-line-table.test

 # RUN: dsymutil -oso-prepend-path %p/../Inputs -y %s -f -o - | llvm-dwarfdump - --debug-line | FileCheck %s
+#
+# RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs -y %s -f -o - | llvm-dwarfdump - --debug-line | FileCheck %s
 
 # This test runs dsymutil on an object file with non-standard (as far
 # as llvm is concerned) line table settings.
 
 ---
 triple:          'x86_64-apple-darwin'
 objects:
   - filename: basic2-custom-linetable.macho.x86_64.o

llvm/test/tools/dsymutil/X86/darwin-bundle.test

 REQUIRES: system-darwin
 
 RUN: rm -rf %t
 RUN: mkdir -p %t/dsymdest
 RUN: cat %p/../Inputs/basic.macho.x86_64 > %t/basic.macho.x86_64
 RUN: cat %p/../Inputs/Info.plist > %t/Info.plist
 
 RUN: dsymutil -oso-prepend-path=%p/.. %t/basic.macho.x86_64 -o %t/dsymdest/basic.macho.x86_64.dSYM
 RUN: FileCheck %s --input-file %t/dsymdest/basic.macho.x86_64.dSYM/Contents/Info.plist
 
 RUN: dsymutil -oso-prepend-path=%p/.. %t/basic.macho.x86_64 -toolchain "toolchain&and'some<symbols" -o %t/dsymdest/basic.macho.x86_64.dSYM
 RUN: FileCheck %s --input-file %t/dsymdest/basic.macho.x86_64.dSYM/Contents/Info.plist --check-prefix=CHECK --check-prefix=TOOLCHAIN
 
+RUN: dsymutil --linker llvm -oso-prepend-path=%p/.. %t/basic.macho.x86_64 -o %t/dsymdest/basic.macho.x86_64.dSYM
+RUN: FileCheck %s --input-file %t/dsymdest/basic.macho.x86_64.dSYM/Contents/Info.plist
+
+RUN: dsymutil --linker llvm -oso-prepend-path=%p/.. %t/basic.macho.x86_64 -toolchain "toolchain&and'some<symbols" -o %t/dsymdest/basic.macho.x86_64.dSYM
+RUN: FileCheck %s --input-file %t/dsymdest/basic.macho.x86_64.dSYM/Contents/Info.plist --check-prefix=CHECK --check-prefix=TOOLCHAIN
+
+
 CHECK: <?xml version="1.0" encoding="UTF-8"?>
 CHECK-NEXT: <!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
 CHECK-NEXT: <plist version="1.0">
 CHECK-NEXT:         <dict>
 CHECK-NEXT:                 <key>CFBundleDevelopmentRegion</key>
 CHECK-NEXT:                 <string>English</string>
 CHECK-NEXT:                 <key>CFBundleIdentifier</key>
 CHECK-NEXT:                 <string>com.apple.xcode.dsym.Foo&amp;Bar</string>

llvm/test/tools/dsymutil/X86/dead-stripped.cpp

 // RUN: dsymutil -f -y %p/dummy-debug-map.map -oso-prepend-path %p/../Inputs/dead-stripped -o - | llvm-dwarfdump - --debug-info | FileCheck %s --implicit-check-not "{{DW_AT_low_pc|DW_AT_high_pc|DW_AT_location|DW_TAG|NULL}}"
 
+// RUN: dsymutil --linker llvm -f -y %p/dummy-debug-map.map -oso-prepend-path \
+// RUN: %p/../Inputs/dead-stripped -o - | llvm-dwarfdump - --debug-info | \
+// RUN: FileCheck %s --implicit-check-not \
+// RUN: "{{DW_AT_low_pc|DW_AT_high_pc|DW_AT_location|DW_TAG|NULL}}"
+
 // The test was compiled with:
 // clang++ -O2 -g -c dead-strip.cpp -o 1.o
 
 // The goal of the test is to exercise dsymutil's behavior in presence of
 // functions/variables that have been dead-stripped by the linker but
 // that are still present in the linked debug info (in this case because
 // they have been DW_TAG_import'd in another namespace).
 

llvm/test/tools/dsymutil/X86/debug-loc-base-addr.test

 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/baseaddr/loc1.x86_64 -f -o - | llvm-dwarfdump --debug-info - | FileCheck %s
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/baseaddr/loc1.x86_64 -f -o - | llvm-dwarfdump --debug-info - | FileCheck %s
+
 The test was compiled from a single source:
 $ cat loc1.cpp
 int f1(int i, int j) {
   int x = 5;
   int y = 3;
   int r = i + j;
   int undef;
   x = undef;

llvm/test/tools/dsymutil/X86/dwarf4-linetable.test

 # RUN: dsymutil -f -oso-prepend-path=%p/../Inputs/ -y %s -o - | llvm-dwarfdump -debug-line - | FileCheck %s
 
+# RUN: dsymutil --linker llvm -f -oso-prepend-path=%p/../Inputs/ -y %s -o - | llvm-dwarfdump -debug-line - | FileCheck %s
+
 # Source:
 #   int main() {
 #     return 0;
 #   }
 # Compile with:
 #   clang -gdwarf-4 dwarf4.c -c -o dwarf4.o
 
 ---

llvm/test/tools/dsymutil/X86/dwarf5-addrx.test

 
 RUN: llvm-dwarfdump --verbose %t.dSYM | FileCheck %s --check-prefix DWARF
 
 RUN: dsymutil --update -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/dwarf5/dwarf5-addrx.out -o %t.dSYM 2>&1 | FileCheck %s --allow-empty
 RUN: llvm-dwarfdump --verify %t.dSYM 2>&1 | FileCheck %s
 
 RUN: llvm-dwarfdump --verbose %t.dSYM | FileCheck %s --check-prefix UPDATE-DWARF
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/dwarf5/dwarf5-addrx.out -o %t.dSYM 2>&1 | FileCheck %s --allow-empty
+RUN: llvm-dwarfdump --verify %t.dSYM 2>&1 | FileCheck %s
+
+RUN: llvm-dwarfdump --verbose %t.dSYM | FileCheck %s --check-prefix DWARF
+
+RUN: dsymutil --linker llvm --update -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/dwarf5/dwarf5-addrx.out -o %t.dSYM 2>&1 | FileCheck %s --allow-empty
+RUN: llvm-dwarfdump --verify %t.dSYM 2>&1 | FileCheck %s
+
+RUN: llvm-dwarfdump --verbose %t.dSYM | FileCheck %s --check-prefix UPDATE-DWARF
+
+
 CHECK-NOT: error:
 
 DWARF: DW_TAG_compile_unit
 DWARF:   DW_AT_name [DW_FORM_strp]  {{.*}}     "dwarf5-addrx.c"
 DWARF:   DW_AT_low_pc [DW_FORM_addrx]      (indexed (00000000) address = 0x0000000100000eb0)
 DWARF:   DW_AT_high_pc [DW_FORM_data4]   (0x00000103)
 DWARF:   DW_AT_addr_base [DW_FORM_sec_offset]      (0x00000008)
 DWARF:   DW_TAG_subprogram

llvm/test/tools/dsymutil/X86/dwarf5-call-site-entry-reloc.test

 
 ## The test requires the return PC to match a relocation (in this case the
 ## DW_AT_high_pc of main). Without this change the value would get relocated
 ## twice.
 
 #RUN: dsymutil -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
 #RUN: llvm-dwarfdump %t.dSYM | FileCheck %s -implicit-check-not=DW_AT_call_return_pc
 
+#RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
+#RUN: llvm-dwarfdump %t.dSYM | FileCheck %s -implicit-check-not=DW_AT_call_return_pc
+
 #CHECK: DW_AT_call_return_pc  (0x0000000100000f72)
 #CHECK: DW_AT_call_return_pc  (0x0000000100000f78)
 
 ---
 triple:          'x86_64-apple-darwin'
 objects:
   - filename:        'call-dwarf5.o'
     timestamp:       1675373912
     symbols:
       - { sym: _foo, objAddr: 0x0, binAddr: 0x100000F69, size: 0x2 }
       - { sym: _bar, objAddr: 0x2, binAddr: 0x100000F6B, size: 0x7 }
       - { sym: _main, objAddr: 0x9, binAddr: 0x100000F72, size: 0x6 }
 ...

llvm/test/tools/dsymutil/X86/dwarf5-dw-op-addrx.test

 #RUN: dsymutil -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
 #RUN: llvm-dwarfdump --verify  %t.dSYM | FileCheck %s
 #RUN: llvm-dwarfdump -a --verbose  %t.dSYM | FileCheck %s --check-prefix DWARF-CHECK
 
 #RUN: dsymutil --update -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
 #RUN: llvm-dwarfdump --verify  %t.dSYM | FileCheck %s
 #RUN: llvm-dwarfdump -a --verbose  %t.dSYM | FileCheck %s --check-prefix UPD-DWARF-CHECK
 
+#RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
+#RUN: llvm-dwarfdump --verify  %t.dSYM | FileCheck %s
+#RUN: llvm-dwarfdump -a --verbose  %t.dSYM | FileCheck %s --check-prefix DWARF-CHECK
+
+#RUN: dsymutil --linker llvm --update -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
+#RUN: llvm-dwarfdump --verify  %t.dSYM | FileCheck %s
+#RUN: llvm-dwarfdump -a --verbose  %t.dSYM | FileCheck %s --check-prefix UPD-DWARF-CHECK
+
 #CHECK: No errors.
 
 #DWARF-CHECK: DW_TAG_compile_unit
 #DWARF-CHECK: DW_AT_name {{.*}}"dwarf5-dw-op-addrx.c"
 #DWARF-CHECK: DW_AT_low_pc {{.*}}0x0000000100000fb0
 #DWARF-CHECK: DW_TAG_variable
 #DWARF-CHECK:   DW_AT_name {{.*}}"arr"
 #DWARF-CHECK:   DW_AT_location {{.*}}(DW_OP_addr 0x100001000)

llvm/test/tools/dsymutil/X86/dwarf5-linetable.test

 # RUN: dsymutil -f -oso-prepend-path=%p/../Inputs/ -y %s -o - | llvm-dwarfdump -debug-line -debug-line-str --verbose - | FileCheck %s
 
+# RUN: dsymutil --linker llvm -f -oso-prepend-path=%p/../Inputs/ -y %s -o - | llvm-dwarfdump -debug-line -debug-line-str --verbose - | FileCheck %s
+
 # Source:
 #   int main() {
 #     return 0;
 #   }
 # Compile with:
 #   clang -gdwarf-5 dwarf5-linetable.c -c -o dwarf5-linetable.o
 
 ---

llvm/test/tools/dsymutil/X86/dwarf5-loclists.test

 #RUN: dsymutil -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
 #RUN: llvm-dwarfdump --verify  %t.dSYM | FileCheck %s
 #RUN: llvm-dwarfdump -a --verbose  %t.dSYM | FileCheck %s --check-prefix DWARF-CHECK
 
 #RUN: dsymutil --update -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
 #RUN: llvm-dwarfdump --verify  %t.dSYM | FileCheck %s
 #RUN: llvm-dwarfdump -a --verbose  %t.dSYM | FileCheck %s --check-prefix UPD-DWARF-CHECK
 
+#RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
+#RUN: llvm-dwarfdump --verify  %t.dSYM | FileCheck %s
+#RUN: llvm-dwarfdump -a --verbose  %t.dSYM | FileCheck %s --check-prefix DWARF-CHECK
+
+#RUN: dsymutil --linker llvm --update -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
+#RUN: llvm-dwarfdump --verify  %t.dSYM | FileCheck %s
+#RUN: llvm-dwarfdump -a --verbose  %t.dSYM | FileCheck %s --check-prefix UPD-DWARF-CHECK
+
 #CHECK: No errors.
 
 #DWARF-CHECK: DW_TAG_formal_parameter
 #DWARF-CHECK: DW_AT_name {{.*}} "dwarf5-loclists.c"
 #DWARF-CHECK-NOT: DW_AT_loclists_base
 #DWARF-CHECK: DW_TAG_formal_parameter
 #DWARF-CHECK:   DW_AT_location [DW_FORM_sec_offset]   (0x0000000c:
 #DWARF-CHECK:     [0x0000000100000f70, 0x0000000100000f87): DW_OP_reg5 RDI

llvm/test/tools/dsymutil/X86/dwarf5-rnglists.test

 ## }
 
 ## $ clang -gdwarf-5 dwarf5-rnglists.c -c -O2 -o dwarf5-rnglists.o
 ## $ clang -gdwarf-5 dwarf5-rnglists.o -o dwarf5-rnglists
 
 #RUN: dsymutil -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
 #RUN: llvm-dwarfdump --verify  %t.dSYM | FileCheck %s
 #RUN: llvm-dwarfdump -a --verbose  %t.dSYM | FileCheck %s --check-prefix DWARF-CHECK
-#
+
 #RUN: dsymutil --update -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
 #RUN: llvm-dwarfdump --verify  %t.dSYM | FileCheck %s
 #RUN: llvm-dwarfdump -a --verbose  %t.dSYM | FileCheck %s --check-prefix UPD-DWARF-CHECK
 
+#RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
+#RUN: llvm-dwarfdump --verify  %t.dSYM | FileCheck %s
+#RUN: llvm-dwarfdump -a --verbose  %t.dSYM | FileCheck %s --check-prefix DWARF-CHECK
+
+#RUN: dsymutil --linker llvm --update -oso-prepend-path %p/../Inputs -y %s -o %t.dSYM
+#RUN: llvm-dwarfdump --verify  %t.dSYM | FileCheck %s
+#RUN: llvm-dwarfdump -a --verbose  %t.dSYM | FileCheck %s --check-prefix UPD-DWARF-CHECK
+
 #CHECK: No errors.
 
 #DWARF-CHECK: DW_TAG_compile_unit
 #DWARF-CHECK:   DW_AT_addr_base [DW_FORM_sec_offset]      (0x00000008)
 #DWARF-CHECK: DW_TAG_lexical_block
 #DWARF-CHECK:   DW_AT_ranges [DW_FORM_sec_offset]     (0x0000000c
 #DWARF-CHECK:      [0x0000000100000f79, 0x0000000100000f96)
 #DWARF-CHECK:      [0x0000000100000fad, 0x0000000100000fb4))

llvm/test/tools/dsymutil/X86/eh_frame.test

 $ clang eh_frame.cpp -g -c -o eh_frame.o
 $ ld -no_compact_unwind eh_frame.o -o eh_frame.out
 
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/eh_frame/eh_frame.out -o %t.dSYM
 RUN: llvm-dwarfdump --verify %t.dSYM
 RUN: llvm-otool -s __TEXT __eh_frame %p/../Inputs/private/tmp/eh_frame/eh_frame.out | FileCheck %s
 RUN: llvm-otool -s __TEXT __eh_frame %t.dSYM/Contents/Resources/DWARF/eh_frame.out | FileCheck %s
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/eh_frame/eh_frame.out -o %t.dSYM
+RUN: llvm-dwarfdump --verify %t.dSYM
+RUN: llvm-otool -s __TEXT __eh_frame %p/../Inputs/private/tmp/eh_frame/eh_frame.out | FileCheck %s
+RUN: llvm-otool -s __TEXT __eh_frame %t.dSYM/Contents/Resources/DWARF/eh_frame.out | FileCheck %s
+
 CHECK: 14 00 00 00 00 00 00 00 01 7a 52 00 01 78 10 01
 CHECK: 10 0c 07 08 90 01 00 00

llvm/test/tools/dsymutil/X86/empty-CU.test

 RUN: llvm-mc %p/../Inputs/empty-CU.s -filetype obj -triple x86_64-apple-darwin -o %t.o
 RUN: dsymutil --update -f %t.o -o - | llvm-dwarfdump -v - -debug-info | FileCheck %s
 
+RUN: dsymutil --linker llvm --update -f %t.o -o - | llvm-dwarfdump -v - -debug-info | FileCheck %s
+
 CHECK: .debug_info contents:
 CHECK: 0x00000000: Compile Unit: length = 0x00000008, format = DWARF32, version = 0x0003, abbr_offset = 0x0000, addr_size = 0x04 (next unit at 0x0000000c)
 
 CHECK: 0x0000000b: DW_TAG_compile_unit [1]

llvm/test/tools/dsymutil/X86/fat-archive-input-i386.test

 # RUN: dsymutil -f -oso-prepend-path=%p/../Inputs -y %s -o - | llvm-dwarfdump -debug-info - | FileCheck %s
 
+# RUN: dsymutil --linker llvm -f -oso-prepend-path=%p/../Inputs -y %s -o - | llvm-dwarfdump -debug-info - | FileCheck %s
+
 ---
 triple:          'i386-apple-darwin'
 objects:
   - filename: libfat-test.a(fat-test.o)
     symbols:
       - { sym: _i386_var, objAddr: 0x0, binAddr: 0x1000, size: 0x4 }
 ...
 
 # CHECK: .debug_info contents:
 # CHECK: DW_TAG_variable
 # CHECK-NOT: {{DW_TAG|NULL}}
 # CHECK:  DW_AT_name{{.*}}"i386_var"
 

llvm/test/tools/dsymutil/X86/fat-object-input-x86_64.test

 # RUN: dsymutil -f -oso-prepend-path=%p/../Inputs -y %s -o - | llvm-dwarfdump -debug-info - | FileCheck %s
 
+# RUN: dsymutil --linker llvm -f -oso-prepend-path=%p/../Inputs -y %s -o - | llvm-dwarfdump -debug-info - | FileCheck %s
+
 ---
 triple:          'x86_64-apple-darwin'
 objects:
   - filename: fat-test.o
     symbols:
       - { sym: _x86_64_var, objAddr: 0x0, binAddr: 0x1000, size: 0x4 }
 ...
 
 # CHECK: .debug_info contents:
 # CHECK: DW_TAG_variable
 # CHECK-NOT: {{DW_TAG|NULL}}
 # CHECK:  DW_AT_name{{.*}}"x86_64_var"
 

llvm/test/tools/dsymutil/X86/fat-object-input-x86_64h.test

 # RUN: dsymutil -f -oso-prepend-path=%p/../Inputs -y %s -o - | llvm-dwarfdump -debug-info - | FileCheck %s
 
+# RUN: dsymutil --linker llvm -f -oso-prepend-path=%p/../Inputs -y %s -o - | llvm-dwarfdump -debug-info - | FileCheck %s
+
 ---
 triple:          'x86_64h-apple-darwin'
 objects:
   - filename: fat-test.o
     symbols:
       - { sym: _x86_64h_var, objAddr: 0x0, binAddr: 0x1000, size: 0x4 }
 ...
 
 # CHECK: .debug_info contents:
 # CHECK: DW_TAG_variable
 # CHECK-NOT: {{DW_TAG|NULL}}
 # CHECK:  DW_AT_name{{.*}}"x86_64h_var"
 

llvm/test/tools/dsymutil/X86/generate-empty-CU.test

 # RUN: dsymutil -f -o - -oso-prepend-path=%p/.. -y %s | llvm-dwarfdump -v - | FileCheck %s
 
+# RUN: dsymutil --linker llvm -f -o - -oso-prepend-path=%p/.. -y %s | llvm-dwarfdump -v - | FileCheck %s
+
 # This test on links the Dwarf for an LTO binary and on purpose doesn't retain
-# any symbol in the second CU out of 3. To be valid DWARF ssymutil must not
+# any symbol in the second CU out of 3. To be valid DWARF dsymutil must not
 # generate an empty CU but omit it.
 
 ---
 triple:          'x86_64-apple-darwin'
 objects:
   - filename:        /Inputs/basic-lto.macho.x86_64.o
     timestamp:       1417654896
     symbols:
       - { sym: _main, objAddr: 0x0000000000000000, binAddr: 0x0000000100000F40, size: 0x00000010 }
       - { sym: _bar, objAddr: 0x0000000000000050, binAddr: 0x0000000100000F90, size: 0x00000024 }
 ...
 
 .debug_info contents:
 CHECK: Compile Unit: length = 0x0000007d, format = DWARF32, version = 0x0002, abbr_offset = 0x0000, addr_size = 0x08 (next unit at 0x00000081)
 
 CHECK: DW_TAG_compile_unit
 CHECK:        DW_AT_name {{.*}} "basic1.c"
 CHECK:   DW_TAG_subprogram
                 DW_AT_name {{.*}} "main"
 
-CHECK: 0x00000081: Compile Unit: length = 0x00000089, format = DWARF32, version = 0x0002, abbr_offset = 0x0000, addr_size = 0x08 (next unit at 0x0000010e)
+CHECK: 0x00000081: Compile Unit: length = 0x00000089, format = DWARF32, version = 0x0002, abbr_offset = 0x00{{00|53}}, addr_size = 0x08 (next unit at 0x0000010e)
 
 CHECK: DW_TAG_compile_unit
 CHECK:        DW_AT_name {{.*}} "basic3.c"
 
-CHECK:   DW_TAG_subprogram [7] *
+CHECK:   DW_TAG_subprogram
 CHECK:          DW_AT_name {{.*}} = "bar"
+
+CHECK-NOT: DW_TAG_compile_unit

llvm/test/tools/dsymutil/X86/global_downgraded_to_static.c

 // REQUIRES : system-darwin
-// RUN: dsymutil -oso-prepend-path %p/.. -dump-debug-map %p/../Inputs/global_downgraded_to_static.x86_64 2>&1 | FileCheck %s
+// RUN: dsymutil -oso-prepend-path %p/.. -dump-debug-map \
+// RUN: %p/../Inputs/global_downgraded_to_static.x86_64 2>&1 | FileCheck %s
+//
+// RUN: dsymutil --linker llvm -oso-prepend-path %p/.. -dump-debug-map \
+// RUN: %p/../Inputs/global_downgraded_to_static.x86_64 2>&1 | FileCheck %s
 //
 //  To build:
 //    clang -g -c -DFILE1 global_downgraded_to_static.c -o 1.o
 //    clang -g -c -DFILE2 global_downgraded_to_static.c -o 2.o
 //    ld -r -exported_symbol _foo 1.o -o 1.r.o
 //    clang 1.r.o 2.o -o global_downgraded_to_static.x86_64
 
 #if defined(FILE1)

llvm/test/tools/dsymutil/X86/inlined-static-variable.cpp

 // RUN: dsymutil -f -y %p/dummy-debug-map.map -oso-prepend-path %p/../Inputs/inlined-static-variable -o - | llvm-dwarfdump - | FileCheck %s --implicit-check-not "{{DW_AT_low_pc|DW_AT_high_pc|DW_AT_location|DW_TAG|NULL}}"
 
+// RUN: dsymutil --linker llvm -f -y %p/dummy-debug-map.map -oso-prepend-path \
+// RUN: %p/../Inputs/inlined-static-variable -o - | llvm-dwarfdump - | \
+// RUN: FileCheck %s --implicit-check-not \
+// RUN: "{{DW_AT_low_pc|DW_AT_high_pc|DW_AT_location|DW_TAG|NULL}}"
+
 // clang -g -c inlined-static-variable.cpp -o 4.o
 
 // The functions removed and not_removed are not in the debug map and are
 // considered dead, but they are also inlined into the function foo which is
 // in the debug map. Those function-local globals are alive and thus should
 // have locations in the debug info even if their functions do not.
 
 inline __attribute__((always_inline)) int removed() {

llvm/test/tools/dsymutil/X86/keep-func.test

 $ clang++ -O2 -g main.cpp -c -o main.o
 $ clang++ main.o -o main.out
 
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/keep_func/main.out -o %t.omit.dSYM
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/keep_func/main.out -o %t.keep.dSYM -keep-function-for-static
 RUN: llvm-dwarfdump %t.omit.dSYM | FileCheck %s --check-prefix OMIT
 RUN: llvm-dwarfdump %t.keep.dSYM | FileCheck %s --check-prefix KEEP
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/keep_func/main.out -o %t.omit.dSYM
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/keep_func/main.out -o %t.keep.dSYM -keep-function-for-static
+RUN: llvm-dwarfdump %t.omit.dSYM | FileCheck %s --check-prefix OMIT
+RUN: llvm-dwarfdump %t.keep.dSYM | FileCheck %s --check-prefix KEEP
+
 KEEP:     DW_AT_name  ("MyDummyVar")
 KEEP:     DW_AT_name  ("FOO_VAR_TYPE")
 KEEP:     DW_AT_name  ("x1")
 KEEP:     DW_AT_name  ("x2")
 
 OMIT-NOT: DW_AT_name  ("MyDummyVar")
 OMIT-NOT: DW_AT_name  ("FOO_VAR_TYPE")
 OMIT-NOT: DW_AT_name  ("x1")
 OMIT-NOT: DW_AT_name  ("x2")

llvm/test/tools/dsymutil/X86/label.test

 # RUN: dsymutil -oso-prepend-path %p/../Inputs -y %s -f -o - | llvm-dwarfdump - --debug-info | FileCheck %s
 
+# RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs -y %s -f -o - | llvm-dwarfdump - --debug-info | FileCheck %s
+
 # Compile with:
 #  echo -e ".global _foo;\nfoo:\nnop" | clang -x assembler -g - -c -o /tmp/label.o
 
 # CHECK: DW_TAG_label
 # CHECK-NEXT: DW_AT_name  ("foo")
 
 ---
 triple:          'x86_64-apple-darwin'
 objects:
   - filename: label.o
     symbols:
       - { sym: _foo, objAddr: 0x0, binAddr: 0x1000, size: 0x1 }
 ...
 

llvm/test/tools/dsymutil/X86/label2.test

 $ cat label.c
 int main(int argc, char **argv) {
     if (argc) {
         goto foobar;
     }
     return 1;
 foobar:
     return 0;
 }
 
 $ clang -g label.c -c -o label.o
 $ clang label.o -o label.out
 
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/label/label.out -o %t.dSYM
 RUN: llvm-dwarfdump %t.dSYM | FileCheck %s
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/label/label.out -o %t.dSYM
+RUN: llvm-dwarfdump %t.dSYM | FileCheck %s
+
 CHECK:      DW_TAG_label
 CHECK-NEXT:   DW_AT_name    ("foobar")
 CHECK-NEXT:   DW_AT_decl_file       ("/tmp/label{{[/\\]}}label.c")
 CHECK-NEXT:   DW_AT_decl_line       (6)
 CHECK-NEXT:   DW_AT_low_pc  (0x0000000100003f9d)

llvm/test/tools/dsymutil/X86/lc_build_version.test

 # RUN: dsymutil -f %p/../Inputs/lc_build_version.x86_64 -o - \
 # RUN:   -oso-prepend-path=%p/.. | obj2yaml | FileCheck %s
 
+# RUN: dsymutil --linker llvm -f %p/../Inputs/lc_build_version.x86_64 -o - \
+# RUN:   -oso-prepend-path=%p/.. | obj2yaml | FileCheck %s
+
 CHECK: LoadCommands:
 CHECK:   - cmd:             LC_BUILD_VERSION
 CHECK-NEXT:    cmdsize:         24
 CHECK-NEXT:    platform:        1
 CHECK-NEXT:    minos:           658944
 CHECK-NEXT:    sdk:             658944
 CHECK-NEXT:    ntools:          0
 CHECK-NEXT:   - cmd:             LC_BUILD_VERSION

llvm/test/tools/dsymutil/X86/location-expression.test

 ## This test checks that size of DW_AT_location attribute
 ## of the DW_FORM_block1 form is correctly written to the
 ## output.
 
 # RUN: yaml2obj %s -o %t.o
 # RUN: echo '---' > %t2.map
 # RUN: echo "triple:          'x86_64-apple-darwin'" >> %t2.map
 # RUN: echo 'objects:'  >> %t2.map
 # RUN: echo " -  filename: '%t.o'" >> %t2.map
 # RUN: echo '    symbols:' >> %t2.map
 # RUN: echo '      - { sym: __Z3foov, objAddr: 0x0, binAddr: 0x10000, size: 0x10 }' >> %t2.map
 # RUN: echo '...' >> %t2.map
 # RUN: dsymutil -y %t2.map -f -o - | llvm-dwarfdump -a --verbose - | FileCheck %s
+# RUN: dsymutil --linker llvm -y %t2.map -f -o - | llvm-dwarfdump -a --verbose - | FileCheck %s
 
 # CHECK: file format Mach-O 64-bit x86-64
 # CHECK: .debug_info contents:
 # CHECK: Compile Unit:
 # CHECK: DW_TAG_compile_unit
 # CHECK: DW_AT_name{{.*}}"CU1"
 # CHECK: 0x0000001b:   DW_TAG_variable
 # CHECK: DW_AT_name {{.*}}"var1"
 # CHECK: DW_AT_type {{.*}}"class1"
-# CHECK:   DW_AT_location [DW_FORM_block1]  (DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address)
+# CHECK:   DW_AT_location [DW_FORM_block1]  (DW_OP_const8u 0x{{.*}}, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address)
 # CHECK: 0x000000ab:   DW_TAG_variable
 # CHECK: DW_AT_name {{.*}}"var2"
 # CHECK: DW_AT_type {{.*}}"class1"
-# CHECK:   DW_AT_location [DW_FORM_block]  (DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address)
+# CHECK:   DW_AT_location [DW_FORM_block]  (DW_OP_const8u 0x{{.*}}, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address, DW_OP_const8u 0x2000, DW_OP_form_tls_address)
 # CHECK: 0x00000146:   DW_TAG_variable
 # CHECK: DW_AT_name {{.*}}"var3"
 # CHECK: DW_AT_type {{.*}}"class1"
 #
 
 --- !mach-o
 FileHeader:
   magic:      0xFEEDFACF
Sections:
         reserved3: 0x00000000
       - sectname:  __debug_info
         segname:   __DWARF
         addr:      0x000000000000100
         size:      0x15e
         offset:    0x00000410
         align:     0
         reloff:    0x00000600
-        nreloc:    1
+        nreloc:    2
         flags:     0x02000000
         reserved1: 0x00000000
         reserved2: 0x00000000
         reserved3: 0x00000000
         relocations:
-          - address:         0x1FC
+          - address:         0x30
+            symbolnum:       1
+            pcrel:           true
+            length:          3
+            extern:          true
+            type:            0
+            scattered:       false
+            value:           0
+          - address:         0xc2
             symbolnum:       1
             pcrel:           true
             length:          3
             extern:          true
             type:            0
             scattered:       false
             value:           0
   - cmd:             LC_SYMTAB

llvm/test/tools/dsymutil/X86/mismatch.m

clang -cc1 -emit-obj -fmodules -fmodule-map-file=modules.modulemap \
       -fdisable-module-hash mismatch.m -o /dev/null
 */
 
 // RUN: rm -rf %t.dir && mkdir %t.dir
 // RUN: cp %p/../Inputs/mismatch/1.o %p/../Inputs/mismatch/mismatch.pcm %t.dir
 // RUN: cp %p/../Inputs/mismatch/1.o %t.dir/2.o
 // RUN: dsymutil --verbose -f -oso-prepend-path=%t.dir \
 // RUN:   -y %p/dummy-debug-map.map -o %t.bin 2>&1 | FileCheck %s
+// RUN: dsymutil --linker llvm --verbose -f -oso-prepend-path=%t.dir \
+// RUN:   -y %p/dummy-debug-map.map -o %t.bin 2>&1 | FileCheck %s
 
 @import mismatch;
 
 void f() {}
 // Mismatch after importing the module.
 // CHECK: warning: hash mismatch
 // Mismatch in the cache.
 // CHECK: warning: hash mismatch
 // CHECK: cached

llvm/test/tools/dsymutil/X86/modules-dwarf-version.m

 /* Compile with (using the module from the modules.m teastcase):
    clang -c -fmodules -fmodule-map-file=modules.modulemap \
      -gdwarf-2 -gmodules -fmodules-cache-path=. \
      -Xclang -fdisable-module-hash modules.m -o 1.o
 */
 
 // RUN: rm -rf %t.dir
 // RUN: mkdir %t.dir
 // RUN: cp %p/../Inputs/modules/Bar.pcm %t.dir
 // RUN: cp %p/../Inputs/modules-dwarf-version/1.o %t.dir
 // RUN: dsymutil -verify -f -oso-prepend-path=%t.dir \
 // RUN:   -y %p/dummy-debug-map.map -o - \
 // RUN:     | llvm-dwarfdump --debug-info - | FileCheck %s
+// RUN: dsymutil --linker llvm -verify -f -oso-prepend-path=%t.dir \
+// RUN:   -y %p/dummy-debug-map.map -o - \
+// RUN:     | llvm-dwarfdump --debug-info - | FileCheck %s
 
 @import Bar;
 int main(int argc, char **argv) {
   struct Bar bar;
   bar.value = argc;
   return bar.value;
 }
 
 // CHECK: Compile Unit: {{.*}}version = 0x0004
 // CHECK: Compile Unit: {{.*}}version = 0x0002

llvm/test/tools/dsymutil/X86/modules-empty.m

 /* Compile with:
    cat >modules.modulemap <<EOF
      module Empty {
        header "Empty.h"
      }
 EOF
    touch Empty.h
    clang -c -fmodules -fmodule-map-file=modules.modulemap \
      -g -gmodules -fmodules-cache-path=. \
      -Xclang -fdisable-module-hash modules-empty.m -o 1.o
 */
 
 // RUN: rm -rf %t.dir
 // RUN: mkdir %t.dir
-// RUN: cp %p/../Inputs/modules-empty/1.o %p/../Inputs/modules-empty/Empty.pcm %t.dir
+// RUN: cp %p/../Inputs/modules-empty/1.o %p/../Inputs/modules-empty/Empty.pcm \
+// RUN: %t.dir
 // RUN: dsymutil -f -oso-prepend-path=%t.dir \
 // RUN:   -verify \
 // RUN:   -y %p/dummy-debug-map.map -o - \
 // RUN:     | llvm-dwarfdump --debug-info - | FileCheck %s
+// RUN: dsymutil --linker llvm -f -oso-prepend-path=%t.dir \
+// RUN:   -verify \
+// RUN:   -y %p/dummy-debug-map.map -o - \
+// RUN:     | llvm-dwarfdump --debug-info - | FileCheck %s
 
 #include "Empty.h"
 int main() {
   return 0;
 }
 
 // The empty CU from the pcm should not get copied into the dSYM.
 // CHECK: DW_TAG_compile_unit
 // CHECK-NOT: DW_TAG_compile_unit
 

llvm/test/tools/dsymutil/X86/multiple-inputs.test

 RUN: | FileCheck %S/basic-linking-x86.test --check-prefixes=CHECK,ARCHIVE
 RUN: llvm-dwarfdump -a %t.dSYM/Contents/Resources/DWARF/basic-lto.macho.x86_64 | FileCheck %S/basic-lto-linking-x86.test
 RUN: llvm-dwarfdump -a %t.dSYM/Contents/Resources/DWARF/basic-lto-dw4.macho.x86_64 | FileCheck %S/basic-lto-dw4-linking-x86.test
 
 # Multiple inputs in a named bundle in flat mode... impossible.
 RUN: not dsymutil -f -oso-prepend-path=%p/.. %t/basic.macho.x86_64 %t/basic-archive.macho.x86_64 %t/basic-lto.macho.x86_64 %t/basic-lto-dw4.macho.x86_64 -o %t.dSYM 2>&1 | FileCheck %s
 
 CHECK: error: cannot use -o with multiple inputs in flat mode
-

llvm/test/tools/dsymutil/X86/object-prefix-path.test

 RUN: rm -rf %t.dir && mkdir %t.dir && mkdir %t.dir/ModuleCacheRenamed
 RUN: cp %p/../Inputs/module-warnings/1.o %t.dir
 RUN: cp %p/../Inputs/module-warnings/Foo.pcm %t.dir/ModuleCacheRenamed
 
 RUN: dsymutil -verify -f -oso-prepend-path=%t.dir -y \
 RUN:   %p/dummy-debug-map.map -o %t \
 RUN:   -object-prefix-map=/ModuleCache=/ModuleCacheRenamed \
 RUN:   2>&1 | FileCheck %s
 
+RUN: dsymutil --linker llvm -verify -f -oso-prepend-path=%t.dir -y \
+RUN:   %p/dummy-debug-map.map -o %t \
+RUN:   -object-prefix-map=/ModuleCache=/ModuleCacheRenamed \
+RUN:   2>&1 | FileCheck %s
+
 CHECK:     warning: {{.*}}Bar.pcm:
 CHECK-NOT: warning: {{.*}}Foo.pcm:

llvm/test/tools/dsymutil/X86/op-convert-offset.test

 # $ llvm-link op-convert-offset1.bc op-convert-offset0.bc -o op-convert-offset.ll -S
 # $ xcrun clang -c op-convert-offset.ll -O0 -arch x86_64
 # $ xcrun clang -g op-convert-offset.o -O0 -arch x86_64 -o op-convert-offset
 
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/op-convert-offset/op-convert-offset -o %t.dSYM 2>&1
 RUN: llvm-dwarfdump %p/../Inputs/private/tmp/op-convert-offset/op-convert-offset.o 2>&1 | FileCheck %s --check-prefix OBJ
 RUN: llvm-dwarfdump %t.dSYM 2>&1 | FileCheck %s --check-prefix DSYM
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs \
+RUN:  %p/../Inputs/private/tmp/op-convert-offset/op-convert-offset \
+RUN:  -o %t.dSYM 2>&1
+RUN: llvm-dwarfdump \
+RUN:   %p/../Inputs/private/tmp/op-convert-offset/op-convert-offset.o 2>&1 \
+RUN:   | FileCheck %s --check-prefix OBJ
+RUN: llvm-dwarfdump %t.dSYM 2>&1 | FileCheck %s --check-prefix DSYM
+
 OBJ: 0x0000007d:   DW_TAG_base_type
 OBJ:                 DW_AT_name      ("DW_ATE_unsigned_1")
 OBJ:                 DW_AT_encoding  (DW_ATE_unsigned)
 OBJ:                 DW_AT_byte_size (0x01)
 
 OBJ: 0x00000094:     DW_TAG_formal_parameter
 OBJ:                   DW_AT_location        (DW_OP_breg2 RCX+0, DW_OP_constu 0xff, DW_OP_and, DW_OP_convert (0x0000007d) "DW_ATE_unsigned_1", DW_OP_convert (0x00000081) "DW_ATE_unsigned_8", DW_OP_stack_value)
 OBJ:                   DW_AT_name    ("b")
 OBJ:                   DW_AT_type    (0x000000af "_Bool")
 
 DSYM: 0x0000009a:   DW_TAG_base_type
 DSYM:                 DW_AT_name      ("DW_ATE_unsigned_1")
 DSYM:                 DW_AT_encoding  (DW_ATE_unsigned)
 DSYM:                 DW_AT_byte_size (0x01)
 
 DSYM: 0x000000ba:     DW_TAG_formal_parameter
 DSYM:                   DW_AT_location        (DW_OP_breg2 RCX+0, DW_OP_constu 0xff, DW_OP_and, DW_OP_convert (0x0000009a) "DW_ATE_unsigned_1", DW_OP_convert (0x000000a1) "DW_ATE_unsigned_8", DW_OP_stack_value)
 DSYM:                   DW_AT_name    ("b")
-DSYM:                   DW_AT_type    (0x000000d8 "_Bool")
+DSYM:                   DW_AT_type    (0x000000d{{8|a}} "_Bool")

llvm/test/tools/dsymutil/X86/op-convert.test

 # RUN: dsymutil -f -o %t --verify -oso-prepend-path=%p/../Inputs -y %s
 # RUN: llvm-dwarfdump %t | FileCheck %s
 
+# RUN: dsymutil --linker llvm -f -o %t --verify -oso-prepend-path=%p/../Inputs -y %s
+# RUN: llvm-dwarfdump %t | FileCheck %s
+
 ---
 triple:          'x86_64-apple-darwin'
 objects:
   - filename: op-convert.macho.x86_64
     symbols:
       - { sym: _foo, objAddr: 0x0, binAddr: 0x1000, size: 0x4 }
 ...
 

llvm/test/tools/dsymutil/X86/papertrail-warnings.test

 RUN: env RC_DEBUG_OPTIONS=1 dsymutil -f %p/../Inputs/basic.macho.x86_64 -o - | llvm-dwarfdump -v - | FileCheck -DMSG=%errc_ENOENT %s
 
+RUN: env RC_DEBUG_OPTIONS=1 dsymutil --linker llvm -f %p/../Inputs/basic.macho.x86_64 -o - | llvm-dwarfdump -v - | FileCheck -DMSG=%errc_ENOENT %s
+
 CHECK: .debug_info contents:
 CHECK:  Compile Unit:
 CHECK:  DW_TAG_compile_unit [1] *
 CHECK:    DW_AT_producer {{.*}}"dsymutil
 CHECK:    DW_AT_name {{.*}}"/Inputs/basic1.macho.x86_64.o"
 CHECK:    DW_TAG_constant [2]
 CHECK:      DW_AT_name {{.*}}"dsymutil_warning"
 CHECK:      DW_AT_artificial [DW_FORM_flag] (0x01)

llvm/test/tools/dsymutil/X86/reflection-dump.test

 RUN: rm -rf %t.dir && mkdir -p %t.dir/tmp
 RUN: cp %p/../Inputs/main.yaml %t.dir
 RUN: cp %p/../Inputs/test.yaml %t.dir
 RUN: cp %p/../Inputs/reflection_metadata.yaml %t.dir
 RUN: yaml2obj %p/../Inputs/main.yaml -o %t.dir/main
 RUN: yaml2obj %p/../Inputs/test.yaml -o %t.dir/tmp/test-1.o
 RUN: yaml2obj %p/../Inputs/reflection_metadata.yaml -o %t.dir/tmp/reflection_metadata-1.o
 
 RUN: dsymutil -oso-prepend-path=%t.dir %t.dir/main -o %t.dir/main.dSYM
 RUN: llvm-objdump -s %t.dir/main.dSYM/Contents/Resources/DWARF/main | FileCheck %s
 
+RUN: dsymutil --linker llvm -oso-prepend-path=%t.dir %t.dir/main -o %t.dir/main.dSYM
+RUN: llvm-objdump -s %t.dir/main.dSYM/Contents/Resources/DWARF/main | FileCheck %s
+
 REQUIRES: host-byteorder-little-endian
 
 
 CHECK: Contents of section __DWARF,__swift5_assocty:
 CHECK-NEXT: 10000e000 00000000 fcffffff 01000000 08000000  ................
 CHECK-NEXT: 10000e010 f0ffffff ecffffff 00000000 fcffffff  ................
 CHECK-NEXT: 10000e020 01000000 08000000 f0ffffff ecffffff  ................
 

llvm/test/tools/dsymutil/X86/remarks-linking-archive.text

 RUN: rm -rf %t
 RUN: mkdir -p %t
 RUN: cat %p/../Inputs/remarks/basic.macho.remarks.archive.x86_64 > %t/basic.macho.remarks.archive.x86_64
 
 RUN: dsymutil -oso-prepend-path=%p/../Inputs -remarks-prepend-path=%p/../Inputs %t/basic.macho.remarks.archive.x86_64
 
 Check that the remark file in the bundle exists and is sane:
 RUN: llvm-bcanalyzer -dump %t/basic.macho.remarks.archive.x86_64.dSYM/Contents/Resources/Remarks/basic.macho.remarks.archive.x86_64 | FileCheck %s
 
+RUN: dsymutil --linker llvm -oso-prepend-path=%p/../Inputs -remarks-prepend-path=%p/../Inputs %t/basic.macho.remarks.archive.x86_64
+
+Check that the remark file in the bundle exists and is sane:
+RUN: llvm-bcanalyzer -dump %t/basic.macho.remarks.archive.x86_64.dSYM/Contents/Resources/Remarks/basic.macho.remarks.archive.x86_64 | FileCheck %s
+
 Check that we don't error if we're missing remark files from an archive, but we warn instead.
 Instead of creating a new binary, just remove the remarks prepend path.
 RUN: dsymutil -oso-prepend-path=%p/../Inputs %t/basic.macho.remarks.archive.x86_64 2>&1 | FileCheck %s --check-prefix=CHECK-MISSING
 
+RUN: dsymutil --linker llvm -oso-prepend-path=%p/../Inputs %t/basic.macho.remarks.archive.x86_64 2>&1 | FileCheck %s --check-prefix=CHECK-MISSING
+
 CHECK: <Meta
 CHECK: <Remark Num
 CHECK: <Remark Num
 CHECK: <Remark Num
 CHECK: <Remark Num
 CHECK: <Remark Num
 CHECK: <Remark Num
 CHECK: <Remark Num

llvm/test/tools/dsymutil/X86/remarks-linking-bundle-empty.test

 RUN: rm -rf %t
 RUN: mkdir -p %t
 RUN: cat %p/../Inputs/remarks/basic.macho.remarks.empty.x86_64 > %t/basic.macho.remarks.empty.x86_64
 
 RUN: dsymutil -oso-prepend-path=%p/../Inputs -remarks-prepend-path=%p/../Inputs %t/basic.macho.remarks.empty.x86_64
 
 Check that the remark file in the bundle does not exist:
 RUN: not cat %t/basic.macho.remarks.empty.x86_64.dSYM/Contents/Resources/Remarks/basic.macho.remarks.empty.x86_64 2>&1
+
+RUN: dsymutil --linker llvm -oso-prepend-path=%p/../Inputs -remarks-prepend-path=%p/../Inputs %t/basic.macho.remarks.empty.x86_64
+
+Check that the remark file in the bundle does not exist:
+RUN: not cat %t/basic.macho.remarks.empty.x86_64.dSYM/Contents/Resources/Remarks/basic.macho.remarks.empty.x86_64 2>&1

llvm/test/tools/dsymutil/X86/remarks-linking-bundle.test

 RUN: rm -rf %t
 RUN: mkdir -p %t
 RUN: cat %p/../Inputs/remarks/basic.macho.remarks.x86_64 > %t/basic.macho.remarks.x86_64
 
 RUN: dsymutil -oso-prepend-path=%p/../Inputs -remarks-prepend-path=%p/../Inputs %t/basic.macho.remarks.x86_64
 
 Check that the remark file in the bundle exists and is sane:
 RUN: llvm-bcanalyzer -dump %t/basic.macho.remarks.x86_64.dSYM/Contents/Resources/Remarks/basic.macho.remarks.x86_64 | FileCheck %s
 
+RUN: dsymutil --linker llvm -oso-prepend-path=%p/../Inputs -remarks-prepend-path=%p/../Inputs %t/basic.macho.remarks.x86_64
+
+Check that the remark file in the bundle exists and is sane:
+RUN: llvm-bcanalyzer -dump %t/basic.macho.remarks.x86_64.dSYM/Contents/Resources/Remarks/basic.macho.remarks.x86_64 | FileCheck %s
+
 Now emit it in a different format: YAML.
 RUN: dsymutil -remarks-output-format=yaml -oso-prepend-path=%p/../Inputs -remarks-prepend-path=%p/../Inputs %t/basic.macho.remarks.x86_64
 RUN: cat %t/basic.macho.remarks.x86_64.dSYM/Contents/Resources/Remarks/basic.macho.remarks.x86_64 | FileCheck %s --check-prefix=CHECK-YAML
 
+RUN: dsymutil --linker llvm -remarks-output-format=yaml -oso-prepend-path=%p/../Inputs -remarks-prepend-path=%p/../Inputs %t/basic.macho.remarks.x86_64
+RUN: cat %t/basic.macho.remarks.x86_64.dSYM/Contents/Resources/Remarks/basic.macho.remarks.x86_64 | FileCheck %s --check-prefix=CHECK-YAML
+
 CHECK: <Meta
 CHECK: <Remark Num
 CHECK: <Remark Num
 CHECK: <Remark Num
 CHECK: <Remark Num
 CHECK: <Remark Num
 CHECK: <Remark Num
 CHECK: <Remark Num

llvm/test/tools/dsymutil/X86/remarks-linking-fat-bundle.test

 REQUIRES: system-darwin
 
 RUN: rm -rf %t
 RUN: mkdir -p %t
 RUN: cat %p/../Inputs/remarks/fat.macho.remarks.x86 > %t/fat.macho.remarks.x86
 
 RUN: dsymutil -oso-prepend-path=%p/../Inputs -remarks-prepend-path=%p/../Inputs %t/fat.macho.remarks.x86
 
 Check that the remark files in the bundle exist and are all sane:
 RUN: llvm-bcanalyzer -dump %t/fat.macho.remarks.x86.dSYM/Contents/Resources/Remarks/fat.macho.remarks.x86-x86_64h | FileCheck %s
 RUN: llvm-bcanalyzer -dump %t/fat.macho.remarks.x86.dSYM/Contents/Resources/Remarks/fat.macho.remarks.x86-x86_64 | FileCheck %s
 RUN: llvm-bcanalyzer -dump %t/fat.macho.remarks.x86.dSYM/Contents/Resources/Remarks/fat.macho.remarks.x86-i386 | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-i386
 
+RUN: dsymutil --linker llvm -oso-prepend-path=%p/../Inputs -remarks-prepend-path=%p/../Inputs %t/fat.macho.remarks.x86
+
+Check that the remark files in the bundle exist and are all sane:
+RUN: llvm-bcanalyzer -dump %t/fat.macho.remarks.x86.dSYM/Contents/Resources/Remarks/fat.macho.remarks.x86-x86_64h | FileCheck %s
+RUN: llvm-bcanalyzer -dump %t/fat.macho.remarks.x86.dSYM/Contents/Resources/Remarks/fat.macho.remarks.x86-x86_64 | FileCheck %s
+RUN: llvm-bcanalyzer -dump %t/fat.macho.remarks.x86.dSYM/Contents/Resources/Remarks/fat.macho.remarks.x86-i386 | FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-i386
+
 CHECK: <Meta
 CHECK: <Remark Num
 CHECK: <Remark Num
 CHECK-i386: <Remark Num
 CHECK-NOT: <Remark Num

llvm/test/tools/dsymutil/X86/reproducer.test

 # Create a reproducer.
 RUN: env DSYMUTIL_REPRODUCER_PATH=%t.repro dsymutil -gen-reproducer -f -o %t.generate -oso-prepend-path=%t %t/Inputs/basic.macho.x86_64 2>&1 | FileCheck %s --check-prefixes=REPRODUCER
 RUN: llvm-dwarfdump -a %t.generate | FileCheck %s
 
 # Remove the input files and verify that was successful.
 RUN: rm -rf %t
 RUN: not dsymutil -f -o %t.error -oso-prepend-path=%t %t/Inputs/basic.macho.x86_64 2>&1 | FileCheck %s --check-prefix=ERROR
 
+RUN: not dsymutil --linker llvm -f -o %t.error -oso-prepend-path=%t %t/Inputs/basic.macho.x86_64 2>&1 | FileCheck %s --check-prefix=ERROR
+
 # Use the reproducer.
 RUN: dsymutil -use-reproducer %t.repro -f -o - -oso-prepend-path=%t %t/Inputs/basic.macho.x86_64 | llvm-dwarfdump -a - | FileCheck %s
 
+RUN: dsymutil --linker llvm -use-reproducer %t.repro -f -o - -oso-prepend-path=%t %t/Inputs/basic.macho.x86_64 | llvm-dwarfdump -a - | FileCheck %s
+
 # Using a reproducer takes precedence.
 RUN: dsymutil -gen-reproducer -use-reproducer %t.repro -f -o - -oso-prepend-path=%t %t/Inputs/basic.macho.x86_64 | llvm-dwarfdump -a - | FileCheck %s
 
+RUN: dsymutil --linker llvm -gen-reproducer -use-reproducer %t.repro -f -o - -oso-prepend-path=%t %t/Inputs/basic.macho.x86_64 | llvm-dwarfdump -a - | FileCheck %s
+
 CHECK: .debug_info
 CHECK:  DW_TAG_compile_unit
 CHECK-NEXT:    DW_AT_producer ("Apple LLVM version 6.0 (clang-600.0.39) (based on LLVM 3.5svn)")
 CHECK-NEXT:    DW_AT_language (DW_LANG_C99)
 CHECK-NEXT:    DW_AT_name ("basic1.c")
 CHECK-NEXT:    DW_AT_stmt_list (0x00000000)
 CHECK-NEXT:    DW_AT_comp_dir ("/Inputs")
 CHECK-NEXT:    DW_AT_low_pc (0x0000000100000ea0)

llvm/test/tools/dsymutil/X86/statistics.test

 # RUN: dsymutil -statistics -oso-prepend-path=%p/.. %p/../Inputs/basic.macho.x86_64 %p/../Inputs/basic-archive.macho.x86_64 %p/../Inputs/basic-lto.macho.x86_64 %p/../Inputs/basic-lto-dw4.macho.x86_64 -o %t 2>&1 | FileCheck %s
+# RUN: dsymutil --linker llvm -statistics -oso-prepend-path=%p/.. %p/../Inputs/basic.macho.x86_64 %p/../Inputs/basic-archive.macho.x86_64 %p/../Inputs/basic-lto.macho.x86_64 %p/../Inputs/basic-lto-dw4.macho.x86_64 -o %t 2>&1 | FileCheck %s
 #
 # CHECK: -------------------------------------------------------------------------------
 # CHECK-NEXT: Filename                                           Object         dSYM   Change
 # CHECK-NEXT: -------------------------------------------------------------------------------
 # CHECK-DAG: basic2.macho.x86_64.o {{[0-9]+}}b {{[0-9]+}}b{{.*}}{{[0-9]+}}.{{[0-9]+}}%
 # CHECK-DAG: basic3.macho.x86_64.o {{[0-9]+}}b {{[0-9]+}}b{{.*}}{{[0-9]+}}.{{[0-9]+}}%
 # CHECK-DAG: basic1.macho.x86_64.o {{[0-9]+}}b {{[0-9]+}}b{{.*}}{{[0-9]+}}.{{[0-9]+}}%
 # CHECK: -------------------------------------------------------------------------------

llvm/test/tools/dsymutil/X86/swift-ast-x86_64.test

 RUN: dsymutil -oso-prepend-path %p/.. %p/../Inputs/swift-ast.macho.x86_64 -o %T/swift-ast.dSYM -verbose -no-swiftmodule-timestamp | FileCheck %s --check-prefix=DSYMUTIL
 RUN: dsymutil -oso-prepend-path %p/.. %p/../Inputs/swift-ast.macho.x86_64 -o %T/swift-ast.dSYM -verbose | FileCheck %s --check-prefix=DSYMUTIL
 RUN: llvm-readobj --sections --section-data %T/swift-ast.dSYM/Contents/Resources/DWARF/swift-ast.macho.x86_64 | FileCheck %s --check-prefix=READOBJ
 RUN: llvm-dwarfdump --show-section-sizes %T/swift-ast.dSYM/Contents/Resources/DWARF/swift-ast.macho.x86_64 | FileCheck %s --check-prefix=DWARFDUMP
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/.. %p/../Inputs/swift-ast.macho.x86_64 -o %T/swift-ast.dSYM -verbose -no-swiftmodule-timestamp | FileCheck %s --check-prefix=DSYMUTIL
+RUN: dsymutil --linker llvm -oso-prepend-path %p/.. %p/../Inputs/swift-ast.macho.x86_64 -o %T/swift-ast.dSYM -verbose | FileCheck %s --check-prefix=DSYMUTIL
+RUN: llvm-readobj --sections --section-data %T/swift-ast.dSYM/Contents/Resources/DWARF/swift-ast.macho.x86_64 | FileCheck %s --check-prefix=READOBJ
+RUN: llvm-dwarfdump --show-section-sizes %T/swift-ast.dSYM/Contents/Resources/DWARF/swift-ast.macho.x86_64 | FileCheck %s --check-prefix=DWARFDUMP
+
+
 The tested object file has been created by the dummy Swift code:
 let x = 1
 
 Compiled with:
   swiftc /tmp/test.swift -Onone -target x86_64-apple-macosx10.9 -c
   ld swift-ast.o -add_ast_path Inputs/swift-ast.swiftmodule -arch x86_64 -lSystem -macosx_version_min 10.9.0
 
 DSYMUTIL: filename:{{.*}}swift-ast.swiftmodule

llvm/test/tools/dsymutil/X86/swift-dwarf-loc.test

 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/swift-dwarf-loc.macho.x86_64 -no-output -verbose | FileCheck %s
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/swift-dwarf-loc.macho.x86_64 -no-output -verbose | FileCheck %s
+
 This test checks that dsymutil generates a valid dwarf location for a symbol with no flags set.
 
 The following IR was compiled for x86_64-apple:
 ; ModuleID = '-'
 source_filename = "-"
 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-apple-macosx10.12"
 

llvm/test/tools/dsymutil/X86/tail-call-linking.test

 RUN: dsymutil -oso-prepend-path=%p %p/Inputs/tail-call.macho.x86_64 -o %t.dSYM
 RUN: llvm-dwarfdump %t.dSYM | FileCheck %s -implicit-check-not=DW_AT_call_pc
 
+RUN: dsymutil --linker llvm -oso-prepend-path=%p %p/Inputs/tail-call.macho.x86_64 -o %t.dSYM
+RUN: llvm-dwarfdump %t.dSYM | FileCheck %s -implicit-check-not=DW_AT_call_pc
+
 CHECK: DW_AT_call_pc  (0x0000000100000f95)

llvm/test/tools/dsymutil/X86/thinlto.test

 {
   function2();
 }
 
 $ xcrun clang++ -g -flto=thin -O2 foo.cpp bar.cpp -c
 $ xcrun clang++ -flto=thin foo.o bar.o -Xlinker -object_path_lto -Xlinker lto -shared -o foobar.dylib
 
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/thinlto/foobar.dylib -o %t.dSYM 2>&1 | FileCheck %s --allow-empty
+
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/thinlto/foobar.dylib -o %t.dSYM 2>&1 | FileCheck %s --allow-empty
+
 CHECK-NOT: could not find object file symbol for symbol __ZZ9function2vE12magic_static
 CHECK-NOT: could not find object file symbol for symbol __ZGVZ9function2vE12magic_static

llvm/test/tools/dsymutil/X86/timestamp-mismatch.test

 RUN: mkdir -p %t/Inputs
 RUN: cp %p/../Inputs/basic.macho.x86_64 %t/Inputs
 RUN: cp %p/../Inputs/basic1.macho.x86_64.o %t/Inputs
 RUN: cp %p/../Inputs/basic2.macho.x86_64.o %t/Inputs
 RUN: cp %p/../Inputs/basic3.macho.x86_64.o %t/Inputs
 RUN: dsymutil -oso-prepend-path=%t %t/Inputs/basic.macho.x86_64 -o %t.dSYM 2>&1 | FileCheck %s
 
+RUN: dsymutil --linker llvm -oso-prepend-path=%t %t/Inputs/basic.macho.x86_64 -o %t.dSYM 2>&1 | FileCheck %s
+
 CHECK: warning: {{.*}}/Inputs/basic1.macho.x86_64.o: timestamp mismatch between object file ({{.*}}) and debug map ({{.*}})
 CHECK: warning: {{.*}}/Inputs/basic2.macho.x86_64.o: timestamp mismatch between object file ({{.*}}) and debug map ({{.*}})
 CHECK: warning: {{.*}}/Inputs/basic3.macho.x86_64.o: timestamp mismatch between object file ({{.*}}) and debug map ({{.*}})

llvm/test/tools/dsymutil/X86/tls-variable.test

 ## This test checks that thread local storage variables
 ## are preserved.
 
 # RUN: yaml2obj %s -o %t.o
 # RUN: echo '---' > %t2.map
 # RUN: echo "triple:          'x86_64-apple-darwin'" >> %t2.map
 # RUN: echo 'objects:'  >> %t2.map
 # RUN: echo " -  filename: '%t.o'" >> %t2.map
 # RUN: echo '    symbols:' >> %t2.map
 # RUN: echo '      - { sym: __Z3foov, objAddr: 0x0, binAddr: 0x10000, size: 0x10 }' >> %t2.map
 # RUN: echo '...' >> %t2.map
 # RUN: dsymutil -y %t2.map --keep-function-for-static -f -o - | llvm-dwarfdump -a - | FileCheck %s
+# RUN: dsymutil --linker llvm -y %t2.map --keep-function-for-static -f -o - | llvm-dwarfdump -a - | FileCheck %s
 
 # CHECK: file format Mach-O 64-bit x86-64
 # CHECK: .debug_info contents:
 # CHECK: Compile Unit:
 # CHECK: DW_TAG_compile_unit
 # CHECK: DW_AT_name{{.*}}"CU1"
 # CHECK: DW_TAG_subprogram
 # CHECK: DW_AT_name{{.*}}"foo"

llvm/test/tools/dsymutil/X86/union-fwd-decl.test

 $ clang++ -O0 -g use.cpp -c -o use.o
 $ clang++ use.o container.o -o a.out
 
 Note that the link order in the last command matters for this test.
 
 RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/union/a.out -o %t.dSYM
 RUN: llvm-dwarfdump %t.dSYM | FileCheck %s
 
+RUN: dsymutil --linker llvm -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/union/a.out -o %t.dSYM
+RUN: llvm-dwarfdump %t.dSYM | FileCheck %s
+
 CHECK: DW_TAG_compile_unit
 
 CHECK:          DW_AT_name      ("Container_ivars")
 CHECK-NEXT:     DW_AT_declaration       (true)
 
 CHECK: DW_TAG_compile_unit
 
 CHECK:          DW_AT_name      ("Container_ivars")
 CHECK-NEXT:     DW_AT_byte_size (0x01)
 CHECK-NEXT:     DW_AT_decl_file ("{{.*}}container.cpp")
 CHECK-NEXT:     DW_AT_decl_line (4)

llvm/test/tools/dsymutil/X86/verify.test

 # RUN: not dsymutil -verify-dwarf=all -verbose -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefixes=VERBOSE-INPUT-FAIL
 
 # VERBOSE-INPUT-FAIL-DAG: error: Abbreviation declaration contains multiple DW_AT_language attributes.
 # QUIET-INPUT-FAIL-DAG: warning: input verification failed
 # QUIET-OUTPUT-FAIL-DAG: error: output verification failed
 # QUIET-SUCCESS-NOT: input verification failed
 # QUIET-SUCCESS-NOT: output verification failed
 # BOGUS: error: invalid verify type specified: 'bogus'
+#
+# Positive tests in regular and verbose mode.
+# RUN: dsymutil --linker llvm -verify -oso-prepend-path=%p/.. %p/../Inputs/basic.macho.x86_64 %p/../Inputs/basic-archive.macho.x86_64 %p/../Inputs/basic-lto.macho.x86_64 %p/../Inputs/basic-lto-dw4.macho.x86_64 -o %t 2>&1 | FileCheck %s --allow-empty --check-prefix=QUIET-SUCCESS
+# RUN: dsymutil --linker llvm -verify -verbose -oso-prepend-path=%p/.. %p/../Inputs/basic.macho.x86_64 %p/../Inputs/basic-archive.macho.x86_64 %p/../Inputs/basic-lto.macho.x86_64 %p/../Inputs/basic-lto-dw4.macho.x86_64 -o %t 2>&1 | FileCheck %s --check-prefixes=QUIET-SUCCESS,VERBOSE
+#
+# # Negative output tests in regular and verbose mode.
+# (Invalid object generated from ../Inputs/invalid.s by modified the low PC.)
+# RUN: not dsymutil --linker llvm -verify -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefix=QUIET-OUTPUT-FAIL
+# RUN: not dsymutil --linker llvm -verify-dwarf=output -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefix=QUIET-OUTPUT-FAIL
+# RUN: not dsymutil --linker llvm -verify -verbose -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefixes=QUIET-OUTPUT-FAIL,VERBOSE
+#
+# # Negative input & output tests in regular and verbose mode. Only output failures result in a non-zero exit code.
+# RUN: dsymutil --linker llvm -verify-dwarf=input -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefix=QUIET-INPUT-FAIL
+# RUN: dsymutil --linker llvm -verify-dwarf=input -verbose -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefix=QUIET-INPUT-FAIL
+# RUN: dsymutil --linker llvm -verify-dwarf=none -verbose -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefixes=QUIET-SUCCESS
+# RUN: not dsymutil --linker llvm -verify-dwarf=bogus -verbose -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefixes=BOGUS
+# RUN: not dsymutil --linker llvm -verify-dwarf=all -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefixes=QUIET-OUTPUT-FAIL,QUIET-INPUT-FAIL
+# RUN: not dsymutil --linker llvm -verify-dwarf=all -verbose -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefixes=VERBOSE-INPUT-FAIL
+
 
 ---
 triple:          'x86_64-apple-darwin'
 objects:
   - filename:        invalid.o
     timestamp:       1518197670
     symbols:
       - { sym: _main, objAddr: 0x0000000000000010, binAddr: 0x0000000100000FB0, size: 0x00000008 }
       - { sym: _g, objAddr: 0x0000000000000000, binAddr: 0x0000000100000FA0, size: 0x00000010 }
 ...

llvm/test/tools/llvm-dwarfutil/ELF/X86/DWARFLinkerParallel/gc-default.test

-## This test checks that debug info related to deleted code (marked with
-## default tombstone value) is removed.
-
-# RUN: yaml2obj %s -o %t.o
-# RUN: llvm-dwarfutil --linker llvm %t.o %t1.out 2>&1 | FileCheck %s --allow-empty
-
-#CHECK: LLVM parallel dwarflinker is not implemented yet.
-
---- !ELF
-FileHeader:
-  Class:    ELFCLASS64
-  Data:     ELFDATA2LSB
-  Type:     ET_REL
-  Machine:  EM_X86_64
-Sections:
-  - Name:            .text
-    Type:            SHT_PROGBITS
-    Flags:           [ SHF_ALLOC, SHF_EXECINSTR ]
-    Address:         0x1000
-    Size:            0x1b
-DWARF:
-  debug_abbrev:
-    - Table:
-      - Tag:      DW_TAG_compile_unit
-        Children: DW_CHILDREN_yes
-        Attributes:
-          - Attribute: DW_AT_producer
-            Form:      DW_FORM_string
-          - Attribute: DW_AT_language
-            Form:      DW_FORM_data2
-          - Attribute: DW_AT_name
-            Form:      DW_FORM_string
-          - Attribute: DW_AT_low_pc
-            Form:      DW_FORM_addr
-          - Attribute: DW_AT_high_pc
-            Form:      DW_FORM_data8
-      - Tag:      DW_TAG_subprogram
-        Children: DW_CHILDREN_no
-        Attributes:
-          - Attribute: DW_AT_name
-            Form:      DW_FORM_string
-          - Attribute: DW_AT_low_pc
-            Form:      DW_FORM_addr
-          - Attribute: DW_AT_high_pc
-            Form:      DW_FORM_data8
-          - Attribute: DW_AT_type
-            Form:      DW_FORM_ref4
-      - Tag:      DW_TAG_class_type
-        Children: DW_CHILDREN_yes
-        Attributes:
-          - Attribute: DW_AT_name
-            Form:      DW_FORM_string
-      - Tag:      DW_TAG_member
-        Children: DW_CHILDREN_no
-        Attributes:
-          - Attribute: DW_AT_type
-            Form:      DW_FORM_ref4
-          - Attribute: DW_AT_name
-            Form:      DW_FORM_string
-      - Tag:      DW_TAG_class_type
-        Children: DW_CHILDREN_no
-        Attributes:
-          - Attribute: DW_AT_name
-            Form:      DW_FORM_string
-          - Attribute: DW_AT_declaration
-            Form:      DW_FORM_flag_present
-      - Tag:      DW_TAG_class_type
-        Children: DW_CHILDREN_yes
-        Attributes:
-          - Attribute: DW_AT_name
-            Form:      DW_FORM_string
-          - Attribute: DW_AT_declaration
-            Form:      DW_FORM_flag_present
-      - Tag:      DW_TAG_template_type_parameter
-        Children: DW_CHILDREN_no
-        Attributes:
-          - Attribute: DW_AT_type
-            Form:      DW_FORM_ref4
-      - Tag:      DW_TAG_base_type
-        Children: DW_CHILDREN_no
-        Attributes:
-          - Attribute: DW_AT_name
-            Form:      DW_FORM_string
-  debug_info:
-    - Version: 4
-      Entries:
-        - AbbrCode: 1
-          Values:
-            - CStr: by_hand
-            - Value:  0x04
-            - CStr: CU1
-            - Value:  0x1000
-            - Value:  0x1b
-        - AbbrCode: 3
-          Values:
-            - CStr: class1
-        - AbbrCode: 4
-          Values:
-            - Value:  0x0000006c
-            - CStr: member1
-        - AbbrCode: 0
-        - AbbrCode: 3
-          Values:
-            - CStr: class2
-        - AbbrCode: 4
-          Values:
-            - Value:  0x0000006c
-            - CStr: member1
-        - AbbrCode: 0
-        - AbbrCode: 3
-          Values:
-            - CStr: class3
-        - AbbrCode: 4
-          Values:
-            - Value:  0x0000006c
-            - CStr: member1
-        - AbbrCode: 0
-        - AbbrCode: 8
-          Values:
-            - CStr: int
-        - AbbrCode: 2
-          Values:
-            - CStr: foo1
-            - Value:  0x1000
-            - Value:  0x10
-            - Value:  0x0000002a
-        - AbbrCode: 2
-          Values:
-            - CStr: foo2
-            - Value:  0x0
-            - Value:  0x100
-            - Value:  0x00000040
-        - AbbrCode: 0
-...

llvm/test/tools/llvm-dwarfutil/ELF/X86/dwarf4-macro-short.test

 ## This test checks DWARFv4 DW_MACINFO_start_file
 ## , DW_MACINFO_end_file, DW_MACINFO_define,
 ## DW_MACINFO_UNDEF attributes.
 
 # RUN: yaml2obj %s -o %t.o
 # RUN: llvm-dwarfutil %t.o %t1
 # RUN: llvm-dwarfdump --verify %t1 | FileCheck --check-prefix=VERIFY %s
 # RUN: llvm-dwarfdump -a %t1 | FileCheck %s
 
+# RUN: llvm-dwarfutil --linker llvm %t.o %t1
+# RUN: llvm-dwarfdump --verify %t1 | FileCheck --check-prefix=VERIFY %s
+# RUN: llvm-dwarfdump -a %t1 | FileCheck %s
+
 # VERIFY: No errors.
 
 ##  Content:        "03000201064400020744000400":
 #
 ##  .byte   3    # DW_MACINFO_start_file
 ##  .byte   0    # Line Number
 ##  .byte   2    # File Number
 ##  .byte   1    # DW_MACINFO_define

llvm/test/tools/llvm-dwarfutil/ELF/X86/dwarf4-macro.test

 ## }
 
 ## Check that macro table preserved during garbage collection.
 #
 #RUN: llvm-dwarfutil --garbage-collection %p/Inputs/dwarf4-macro.out %t1
 #RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
 #RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefix=MACINFO
 
+#RUN: llvm-dwarfutil --linker llvm --garbage-collection %p/Inputs/dwarf4-macro.out %t1
+#RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+#RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefix=MACINFO
+
 ## Check that macro table preserved during simple copying.
 #
 #RUN: llvm-dwarfutil --no-garbage-collection %p/Inputs/dwarf4-macro.out %t1
 #RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
 #RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefix=MACINFO
 
+#RUN: llvm-dwarfutil --linker llvm --no-garbage-collection %p/Inputs/dwarf4-macro.out %t1
+#RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+#RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefix=MACINFO
+
 ## Check that macro table preserved during updating accelerator tables.
 #RUN: llvm-dwarfutil --no-garbage-collection --build-accelerator=DWARF %p/Inputs/dwarf4-macro.out %t1
 #RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
-#RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefixes=MACINFO,NAMES
+#RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefixes=MACINFO
+
+#RUN: llvm-dwarfutil --linker llvm --no-garbage-collection --build-accelerator=DWARF %p/Inputs/dwarf4-macro.out %t1
+#RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+#RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefixes=MACINFO
 
 #CHECK: No errors.
 
 #MACINFO: .debug_info contents
 #MACINFO: DW_TAG_compile_unit
 #MACINFO: DW_AT_name        ("main.cpp")
 #MACINFO: DW_AT_macro_info (0x[[MAIN_MACRO_OFFSET:[0-9a-f]*]]
 #MACINFO: DW_TAG_compile_unit

 #MACINFO-NEXT: DW_MACINFO_define - lineno: 0 macro: __STDC_HOSTED__ 1
 #MACINFO-NEXT: DW_MACINFO_define - lineno: 0 macro: __cplusplus 201402L
 #MACINFO-NEXT: DW_MACINFO_define - lineno: 0 macro: __STDCPP_DEFAULT_NEW_ALIGNMENT__ 16UL
 #MACINFO-NEXT: DW_MACINFO_define - lineno: 0 macro: __STDCPP_THREADS__ 1
 #MACINFO-NEXT: DW_MACINFO_define - lineno: 0 macro: __STDC_UTF_16__ 1
 #MACINFO-NEXT: DW_MACINFO_define - lineno: 0 macro: __STDC_UTF_32__ 1
 #MACINFO-NEXT: DW_MACINFO_define - lineno: 0 macro: __GCC_HAVE_DWARF2_CFI_ASM 1
 
-
-#NAMES: .debug_names contents
-#NAMES: Name Index

llvm/test/tools/llvm-dwarfutil/ELF/X86/dwarf5-addresses.test

 ## Test that DWARFv5 address attributes and address expression operands
 ## are handled correctly, specifically:
 ## 1. DW_FORM_addrx is correctly recognized and converted into the DW_FORM_addr
 ##    in --garbage-collection case or correctly preserved in --no-garbage-collection case.
 ## 2. DW_OP_addrx is correctly recognized and converted into the DW_OP_addr
 ##    in --garbage-collection case or correctly preserved in --no-garbage-collection case.
 ## 3. DW_OP_constx is correctly recognized and converted into the DW_OP_const[*]u
 ##    in --garbage-collection case or correctly preserved in --no-garbage-collection case.
 
 # RUN: yaml2obj %s -o %t.o
 
 # RUN: llvm-dwarfutil %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix DWARF-CHECK
-#
+
+# RUN: llvm-dwarfutil --linker llvm %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix DWARF-CHECK
+
 # RUN: llvm-dwarfutil --no-garbage-collection %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix UPD-DWARF-CHECK
-#
+
+# RUN: llvm-dwarfutil --linker llvm --no-garbage-collection %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix UPD-DWARF-CHECK
+
 # RUN: llvm-dwarfutil --no-garbage-collection --build-accelerator=DWARF %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix UPD-DWARF-CHECK
 
+# RUN: llvm-dwarfutil --linker llvm --no-garbage-collection --build-accelerator=DWARF %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix UPD-DWARF-CHECK
+
 #CHECK: No errors.
 
 #DWARF-CHECK: DW_TAG_compile_unit
 #DWARF-CHECK:   DW_AT_name [DW_FORM_strp]  {{.*}}     "CU1"
 #DWARF-CHECK:   DW_AT_low_pc [DW_FORM_addrx]      (indexed (00000000) address = 0x0000000000001130)
 #DWARF-CHECK:   DW_AT_high_pc [DW_FORM_data8]   (0x0000000000000060)
 #DWARF-CHECK:   DW_TAG_subprogram
 #DWARF-CHECK:     DW_AT_name  [DW_FORM_strp] {{.*}}   "foo1"

llvm/test/tools/llvm-dwarfutil/ELF/X86/dwarf5-attributes.test

 ## Test that DWARFv5 DW_FORM_implicit_const is correctly recognized
 ## and copied into the result.
 
 # RUN: yaml2obj %s -o %t.o
 
 # RUN: llvm-dwarfutil %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s --check-prefix VERIFY-CHECK
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s
-#
+
+# RUN: llvm-dwarfutil --linker llvm %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s --check-prefix VERIFY-CHECK
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s
+
 # RUN: llvm-dwarfutil --no-garbage-collection %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s --check-prefix VERIFY-CHECK
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s
-#
+
+# RUN: llvm-dwarfutil --linker llvm --no-garbage-collection %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s --check-prefix VERIFY-CHECK
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s
+
 # RUN: llvm-dwarfutil --no-garbage-collection --build-accelerator=DWARF %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s --check-prefix VERIFY-CHECK
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s
 
+# RUN: llvm-dwarfutil --linker llvm --no-garbage-collection --build-accelerator=DWARF %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s --check-prefix VERIFY-CHECK
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s
+
 #VERIFY-CHECK: No errors.
 
 #CHECK: .debug_abbrev
 #CHECK: DW_TAG_compile_unit
 #CHECK: DW_TAG_subprogram
 #CHECK: DW_TAG_base_type
 #CHECK: DW_TAG_variable
 #CHECK: DW_AT_name

llvm/test/tools/llvm-dwarfutil/ELF/X86/dwarf5-line-str.test

 ## Test that DWARFv5 DW_FORM_line_strp and corresponding .debug_line_str
 ## table are correctly recognized and copied into the result.
 
 # RUN: yaml2obj %s -o %t.o
 
 # RUN: llvm-dwarfutil %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s --check-prefix VERIFY-CHECK
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s
-#
+
 # RUN: llvm-dwarfutil --no-garbage-collection %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s --check-prefix VERIFY-CHECK
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s
-#
+
 # RUN: llvm-dwarfutil --no-garbage-collection --build-accelerator=DWARF %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s --check-prefix VERIFY-CHECK
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s
 
+# RUN: llvm-dwarfutil --linker llvm %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s --check-prefix VERIFY-CHECK
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s
+
+# RUN: llvm-dwarfutil --linker llvm --no-garbage-collection %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s --check-prefix VERIFY-CHECK
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s
+
+# RUN: llvm-dwarfutil --linker llvm --no-garbage-collection --build-accelerator=DWARF %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s --check-prefix VERIFY-CHECK
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s
+
 #VERIFY-CHECK: No errors.
 
 #CHECK: .debug_info
 #CHECK: DW_TAG_compile_unit
 #CHECK: DW_TAG_subprogram
 #CHECK: DW_AT_name [DW_FORM_line_strp]  ( .debug_line_str[0x00000000] = "foo1")
 #CHECK: .debug_line
 #CHECK: include_directories[  0] =  .debug_line_str[0x00000000] = "foo1"

llvm/test/tools/llvm-dwarfutil/ELF/X86/dwarf5-loclists.test

 # RUN: llvm-dwarfutil --no-garbage-collection %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix UPD-DWARF-CHECK
 
 # RUN: llvm-dwarfutil --no-garbage-collection --build-accelerator=DWARF %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix UPD-DWARF-CHECK
 
+# RUN: llvm-dwarfutil --linker llvm %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix DWARF-CHECK
+
+# RUN: llvm-dwarfutil --linker llvm --no-garbage-collection %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix UPD-DWARF-CHECK
+
+# RUN: llvm-dwarfutil --linker llvm --no-garbage-collection --build-accelerator=DWARF %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix UPD-DWARF-CHECK
+
 #CHECK: No errors.
 
 #DWARF-CHECK: DW_TAG_compile_unit
 #DWARF-CHECK: DW_AT_name {{.*}}"CU1"
 #DWARF-CHECK-NOT: DW_AT_loclists_base
 #DWARF-CHECK: DW_TAG_variable
 #DWARF-CHECK: DW_AT_name {{.*}}"var1"
 #DWARF-CHECK: DW_AT_location [DW_FORM_sec_offset]      (0x0000000c:

llvm/test/tools/llvm-dwarfutil/ELF/X86/dwarf5-macro-opcodeop.test

 ## This test checks that error is reported if opcode_operands_table_flag
 ## is used.
 
 # RUN: yaml2obj %s -o %t.o
 # RUN: llvm-dwarfutil %t.o %t1 2>&1 | FileCheck --check-prefix=ERR %s
 # RUN: llvm-dwarfdump --verify %t1 | FileCheck --check-prefix=VERIFY %s
 # RUN: llvm-dwarfdump -a %t1 | FileCheck %s
 
+# RUN: llvm-dwarfutil --linker llvm %t.o %t1 2>&1 | FileCheck --check-prefix=ERR %s
+# RUN: llvm-dwarfdump --verify %t1 | FileCheck --check-prefix=VERIFY %s
+# RUN: llvm-dwarfdump -a %t1 | FileCheck %s
+
 # ERR: error: opcode_operands_table is not supported
 
 # VERIFY: No errors.
 
 ##  Content:        "05000403000200":
 #
 ##  .short  5    # Macro information version
 ##  .byte   0    # Flags: 32 bit

llvm/test/tools/llvm-dwarfutil/ELF/X86/dwarf5-macro-short.test

 ## This test checks DWARFv5 DW_MACRO_start_file,
 ## DW_MACRO_end_file, DW_MACRO_define, DW_MACRO_undef,
 ## DW_MACRO_define_strp, DW_MACRO_undef_strp,
 ## DW_MACRO_define_strx, DW_MACRO_undef_strx attributes.
 
 # RUN: yaml2obj %s -o %t.o
 # RUN: llvm-dwarfutil %t.o %t1 2>&1 | FileCheck --check-prefix=WARN %s
 # RUN: llvm-dwarfdump --verify %t1 | FileCheck --check-prefix=VERIFY %s
 # RUN: llvm-dwarfdump -a %t1 | FileCheck %s
 
+# RUN: llvm-dwarfutil --linker llvm %t.o %t1 2>&1 | FileCheck --check-prefix=WARN %s
+# RUN: llvm-dwarfdump --verify %t1 | FileCheck --check-prefix=VERIFY %s
+# RUN: llvm-dwarfdump -a %t1 | FileCheck %s
+
 # WARN: warning: DW_MACRO_define_strx unsupported yet. Convert to DW_MACRO_define_strp.
 # WARN: warning: DW_MACRO_undef_strx unsupported yet. Convert to DW_MACRO_undef_strp.
 # WARN: warning: DW_MACRO_import and DW_MACRO_import_sup are unsupported yet. remove.
 
 # VERIFY: No errors.
 
 ##  Content:        "05000003000201004400020144000503000000000604000000000b03000c040007000000000400":
 #

llvm/test/tools/llvm-dwarfutil/ELF/X86/dwarf5-macro.test

 ## }
 
 ## Check that macro table preserved during garbage collection.
 #
 #RUN: llvm-dwarfutil --garbage-collection %p/Inputs/dwarf5-macro.out %t1
 #RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
 #RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefix=MACRO
 
+#RUN: llvm-dwarfutil --linker llvm --garbage-collection %p/Inputs/dwarf5-macro.out %t1
+#RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+#RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefix=MACRO
+
 ## Check that macro table preserved during simple copying.
 #
 #RUN: llvm-dwarfutil --no-garbage-collection %p/Inputs/dwarf5-macro.out %t1
 #RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
 #RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefix=MACRO
 
+#RUN: llvm-dwarfutil --linker llvm --no-garbage-collection %p/Inputs/dwarf5-macro.out %t1
+#RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+#RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefix=MACRO
+
 ## Check that macro table preserved during updating accelerator tables.
 #RUN: llvm-dwarfutil --no-garbage-collection --build-accelerator=DWARF %p/Inputs/dwarf5-macro.out %t1
 #RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
-#RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefixes=MACRO,NAMES
+#RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefixes=MACRO
+
+#RUN: llvm-dwarfutil --linker llvm --no-garbage-collection --build-accelerator=DWARF %p/Inputs/dwarf5-macro.out %t1
+#RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+#RUN: llvm-dwarfdump -a  %t1 | FileCheck %s --check-prefixes=MACRO
 
 #CHECK: No errors.
 
 #MACRO: .debug_info contents
 #MACRO: DW_TAG_compile_unit
 #MACRO: DW_AT_name        ("main.cpp")
 #MACRO: DW_AT_stmt_list   (0x[[LINE_TABLE_MAIN:[0-9a-f]*]])
 #MACRO: DW_AT_macros (0x[[MAIN_MACRO_OFFSET:[0-9a-f]*]]

 #MACRO-NEXT: DW_MACRO_define_str{{[px]}} - lineno: 0 macro: __STDC__ 1
 #MACRO-NEXT: DW_MACRO_define_str{{[px]}} - lineno: 0 macro: __STDC_HOSTED__ 1
 #MACRO-NEXT: DW_MACRO_define_str{{[px]}} - lineno: 0 macro: __cplusplus 201402L
 #MACRO-NEXT: DW_MACRO_define_str{{[px]}} - lineno: 0 macro: __STDCPP_DEFAULT_NEW_ALIGNMENT__ 16UL
 #MACRO-NEXT: DW_MACRO_define_str{{[px]}} - lineno: 0 macro: __STDCPP_THREADS__ 1
 #MACRO-NEXT: DW_MACRO_define_str{{[px]}} - lineno: 0 macro: __STDC_UTF_16__ 1
 #MACRO-NEXT: DW_MACRO_define_str{{[px]}} - lineno: 0 macro: __STDC_UTF_32__ 1
 #MACRO-NEXT: DW_MACRO_define_str{{[px]}} - lineno: 0 macro: __GCC_HAVE_DWARF2_CFI_ASM 1
-
-#NAMES: .debug_names contents
-#NAMES: Name Index

llvm/test/tools/llvm-dwarfutil/ELF/X86/dwarf5-rnglists.test

 ## Test that DWARFv5 .debug_rnglists is correctly recognized
 ## and converted into the DW_FORM_sec_offset form in --garbage-collection
 ## case or correctly preserved in --no-garbage-collection case.
 
 # RUN: yaml2obj %s -o %t.o
 
 # RUN: llvm-dwarfutil %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix DWARF-CHECK
 
+# RUN: llvm-dwarfutil --linker llvm %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix DWARF-CHECK
+
 # RUN: llvm-dwarfutil --no-garbage-collection %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix UPD-DWARF-CHECK
 
+# RUN: llvm-dwarfutil --linker llvm --no-garbage-collection %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix UPD-DWARF-CHECK
+
 # RUN: llvm-dwarfutil --no-garbage-collection --build-accelerator=DWARF %t.o %t1
 # RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
 # RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix UPD-DWARF-CHECK
 
+# RUN: llvm-dwarfutil --linker llvm --no-garbage-collection --build-accelerator=DWARF %t.o %t1
+# RUN: llvm-dwarfdump -verify %t1 | FileCheck %s
+# RUN: llvm-dwarfdump -a --verbose %t1 | FileCheck %s --check-prefix UPD-DWARF-CHECK
+
 #CHECK: No errors.
 
 #DWARF-CHECK: DW_TAG_compile_unit
 #DWARF-CHECK:   DW_AT_name [DW_FORM_strp]  {{.*}}     "CU1"
 #DWARF-CHECK:   DW_AT_low_pc [DW_FORM_addrx]      (indexed (00000000) address = 0x0000000000001130)
 #DWARF-CHECK:   DW_AT_ranges [DW_FORM_sec_offset] (0x[[CURANGE_OFF:[0-9a-f]*]]
 #DWARF-CHECK:   [0x0000000000001130, 0x0000000000001170))
 #DWARF-CHECK:   DW_TAG_subprogram

llvm/test/tools/llvm-dwarfutil/ELF/X86/gc-default.test

 ## This test checks that debug info related to deleted code (marked with
 ## default tombstone value) is removed.
 
 # RUN: yaml2obj %s -o %t.o
 
 # RUN: llvm-dwarfutil %t.o - | llvm-dwarfdump -a - | FileCheck %s --check-prefixes=CHECK,CHECK-GC
 
 # RUN: llvm-dwarfutil --linker apple %t.o - | llvm-dwarfdump -a - | FileCheck %s --check-prefixes=CHECK,CHECK-GC
 
+# RUN: llvm-dwarfutil --linker llvm %t.o - | llvm-dwarfdump -a - | FileCheck %s --check-prefixes=CHECK,CHECK-GC
+
 # RUN: llvm-dwarfutil --garbage-collection %t.o - | llvm-dwarfdump -a - | FileCheck %s --check-prefixes=CHECK,CHECK-GC
 
 # RUN: llvm-dwarfutil --no-garbage-collection --garbage-collection %t.o - | llvm-dwarfdump -a - | FileCheck %s --check-prefixes=CHECK,CHECK-GC
 
 # RUN: llvm-dwarfutil --garbage-collection --no-garbage-collection %t.o - | llvm-dwarfdump -a - | FileCheck %s --check-prefixes=CHECK,CHECK-NOGC
 
+# RUN: llvm-dwarfutil --linker llvm --garbage-collection --no-garbage-collection %t.o - | llvm-dwarfdump -a - | FileCheck %s --check-prefixes=CHECK,CHECK-NOGC
+
 # RUN: llvm-dwarfutil %t.o --tombstone=universal - | llvm-dwarfdump -a - | FileCheck %s --check-prefixes=CHECK,CHECK-GC
 
+# RUN: llvm-dwarfutil --linker llvm %t.o --tombstone=universal - | llvm-dwarfdump -a - | FileCheck %s --check-prefixes=CHECK,CHECK-GC
+
 # CHECK: DW_TAG_compile_unit
 # CHECK: DW_AT_name{{.*}}"CU1"
 # CHECK: DW_TAG_class_type
 # CHECK: DW_AT_name{{.*}}"class1"
 # CHECK-GC-NOT: DW_TAG_class_type
 # CHECK-GC-NOT: "class2"
 # CHECK-GC-NOT: "class3"
 # CHECK-NOGC: DW_TAG_class_type

llvm/test/tools/llvm-dwarfutil/ELF/X86/gc-func-overlapping-address-ranges.test

 ## This test checks that overlapping function address ranges
 ## are combined during --garbage-collection optimisation.
 
 # RUN: yaml2obj %s -o %t.o
 # RUN: llvm-dwarfutil --garbage-collection %t.o %t1
 # RUN: llvm-dwarfdump -a %t1 | FileCheck %s
 
+# RUN: llvm-dwarfutil --linker llvm --garbage-collection %t.o %t1
+# RUN: llvm-dwarfdump -a %t1 | FileCheck %s
+
 # CHECK: DW_TAG_compile_unit
 # CHECK: DW_AT_name{{.*}}"CU1"
 # CHECK: DW_AT_low_pc{{.*}}0000000000001000
 # CHECK: DW_AT_ranges
 # CHECK: [0x0000000000001000, 0x000000000000102d)
 # CHECK: [0x0000000000002002, 0x000000000000200d)
 # CHECK: [0x000000000000201b, 0x000000000000202a)
 # CHECK: [0x0000000000003002, 0x0000000000003007)

llvm/test/tools/llvm-dwarfutil/ELF/X86/gc-maxpc.test

 ## This test checks that debug info related to deleted code (marked with
 ## tombstone=maxpc) is removed.
 
 ## RUN: yaml2obj %s -o %t.o
 
 # RUN: llvm-dwarfutil --tombstone=maxpc --garbage-collection %t.o - | llvm-dwarfdump -a - | FileCheck %s
 # RUN: llvm-dwarfutil --tombstone=universal --garbage-collection %t.o - | llvm-dwarfdump -a - | FileCheck %s
 
+# RUN: llvm-dwarfutil --linker llvm --tombstone=maxpc --garbage-collection %t.o - | llvm-dwarfdump -a - | FileCheck %s
+# RUN: llvm-dwarfutil --linker llvm --tombstone=universal --garbage-collection %t.o - | llvm-dwarfdump -a - | FileCheck %s
+
 # CHECK: DW_TAG_compile_unit
 # CHECK: DW_AT_name{{.*}}"CU1"
 # CHECK: DW_TAG_class_type
 # CHECK: DW_AT_name{{.*}}"class1"
 # CHECK-NOT: DW_TAG_class_type
 # CHECK-NOT: "class2"
 # CHECK-NOT: "class3"
 # CHECK: DW_TAG_subprogram

llvm/test/tools/llvm-dwarfutil/ELF/X86/gc-no-garbage.test

 ## This test checks that debug info removal optimization (--garbage-collection)
 ## does not affect files which do not have dead debug info.
 
 # RUN: yaml2obj %s -o %t.o
 # RUN: llvm-dwarfutil --tombstone=maxpc --garbage-collection %t.o - | llvm-dwarfdump -a - | FileCheck %s
 
+# RUN: llvm-dwarfutil --linker llvm --tombstone=maxpc --garbage-collection %t.o - | llvm-dwarfdump -a - | FileCheck %s
+
 # CHECK: DW_TAG_compile_unit
 # CHECK: DW_AT_name{{.*}}"CU1"
 # CHECK: DW_TAG_class_type
 # CHECK: DW_AT_name{{.*}}"class1"
 # CHECK: DW_TAG_class_type
 # CHECK: "class2"
 # CHECK: DW_TAG_subprogram
 # CHECK: DW_AT_name{{.*}}"foo1"

llvm/test/tools/llvm-dwarfutil/ELF/X86/gc-unit-overlapping-address-ranges.test

 ## This test checks that overlapping compile unit address ranges
 ## are ignored (i.e. left unchanged) by --garbage-collection
 ## optimisation.
 
 # RUN: yaml2obj %s -o %t.o
 # RUN: llvm-dwarfutil --garbage-collection %t.o %t1
 # RUN: llvm-dwarfdump -a %t1 | FileCheck %s
 
+# RUN: llvm-dwarfutil --linker llvm --garbage-collection %t.o %t1
+# RUN: llvm-dwarfdump -a %t1 | FileCheck %s
+
 # CHECK: DW_TAG_compile_unit
 # CHECK: DW_AT_name{{.*}}"CU1"
 # CHECK: DW_TAG_class_type
 # CHECK: DW_AT_name{{.*}}"class1"
 # CHECK: DW_TAG_subprogram
 # CHECK: DW_AT_name{{.*}}"foo1"
 # CHECK: DW_AT_low_pc{{.*}}0x0000000000001000
 # CHECK: DW_AT_high_pc{{.*}}0x0000000000001010

llvm/test/tools/llvm-dwarfutil/ELF/X86/verify.test

 ## This test checks that debug info contained in the source file is properly
 ## verified by --verify after copying. If --no-garbage-collection is
 ## specified then the verification should fail, otherwise the verification
 ## should succeed.
 
 # RUN: yaml2obj %s -o %t.o
 
 ## Verify resulting debug info after --garbage-collection optimisation.
 # RUN: llvm-dwarfutil %t.o %t1 --verify
+# RUN: llvm-dwarfutil --linker llvm %t.o %t1 --verify
 
 ## Verify separate debug file after --garbage-collection optimisation.
 # RUN: llvm-dwarfutil %t.o --separate-debug-file %t1 --verify
+# RUN: llvm-dwarfutil --linker llvm %t.o --separate-debug-file %t1 --verify
 
 ## Verify not optimised resulting debug info.
 # RUN: not llvm-dwarfutil --no-garbage-collection %t.o %t1 --verify 2>&1 | FileCheck %s -DFILE=%t1
+# RUN: not llvm-dwarfutil --linker llvm --no-garbage-collection %t.o %t1 --verify 2>&1 | FileCheck %s -DFILE=%t1
 
 ## Verify not optimised resulting separate debug file.
 # RUN: not llvm-dwarfutil --no-garbage-collection %t.o --separate-debug-file %t1 --verify 2>&1 | FileCheck %s -DFILE=%t1.debug
+# RUN: not llvm-dwarfutil --linker llvm --no-garbage-collection %t.o --separate-debug-file %t1 --verify 2>&1 | FileCheck %s -DFILE=%t1.debug
 
 ## Check that verification is disabled when destination is stdout.
 # RUN: llvm-dwarfutil %t.o - --verify 2>&1 | FileCheck %s --check-prefix=CHECK-STDOUT
+# RUN: llvm-dwarfutil --linker llvm %t.o - --verify 2>&1 | FileCheck %s --check-prefix=CHECK-STDOUT
 
 # CHECK: error: '[[FILE]]': output verification failed
 # CHECK-STDOUT: warning: verification skipped because writing to stdout
 
 --- !ELF
 FileHeader:
   Class:    ELFCLASS64
   Data:     ELFDATA2LSB

llvm/tools/dsymutil/BinaryHolder.h

private:
     DenseMap<KeyTy, std::unique_ptr<ObjectEntry>> MemberCache;
     std::mutex MemberCacheMutex;
   };
 
   Expected<const ObjectEntry &>
   getObjectEntry(StringRef Filename, TimestampTy Timestamp = TimestampTy());
 
   void clear();
+  void eraseObjectEntry(StringRef Filename);
 
 private:
   /// Cache of static archives. Objects that are part of a static archive are
   /// stored under this object, rather than in the map below.
   StringMap<std::unique_ptr<ArchiveEntry>> ArchiveCache;
   std::mutex ArchiveCacheMutex;
 
   /// Object entries for objects that are not in a static archive.

llvm/tools/dsymutil/BinaryHolder.cpp

 
 void BinaryHolder::clear() {
   std::lock_guard<std::mutex> ArchiveLock(ArchiveCacheMutex);
   std::lock_guard<std::mutex> ObjectLock(ObjectCacheMutex);
   ArchiveCache.clear();
   ObjectCache.clear();
 }
 
+void BinaryHolder::eraseObjectEntry(StringRef Filename) {
+  if (Verbose)
+    WithColor::note() << "erasing '" << Filename << "' from cache\n";
+
+  if (isArchive(Filename)) {
+    StringRef ArchiveFilename = getArchiveAndObjectName(Filename).first;
+    std::lock_guard<std::mutex> Lock(ArchiveCacheMutex);
+    ArchiveCache.erase(ArchiveFilename);
+    return;
+  }
+
+  std::lock_guard<std::mutex> Lock(ObjectCacheMutex);
+  ObjectCache.erase(Filename);
+}
+
 } // namespace dsymutil
 } // namespace llvm

llvm/tools/dsymutil/DwarfLinkerForBinary.cpp

static void dumpDIE(const DWARFDie *DIE, bool Verbose) {
   WithColor::note() << "    in DIE:\n";
   DIE->dump(errs(), 6 /* Indent */, DumpOpts);
 }
 
 /// Report a warning to the user, optionally including information about a
 /// specific \p DIE related to the warning.
 void DwarfLinkerForBinary::reportWarning(Twine Warning, Twine Context,
                                          const DWARFDie *DIE) const {
-  std::lock_guard<std::mutex> Guard(ErrorHandlerMutex);
+  // FIXME: implement warning logging which does not block other threads.
+  if (ErrorHandlerMutex.try_lock()) {
     warn(Warning, Context);
     dumpDIE(DIE, Options.Verbose);
+    ErrorHandlerMutex.unlock();
+  }
 }
 
 void DwarfLinkerForBinary::reportError(Twine Error, Twine Context,
                                        const DWARFDie *DIE) const {
-  std::lock_guard<std::mutex> Guard(ErrorHandlerMutex);
+  // FIXME: implement error logging which does not block other threads.
+  if (ErrorHandlerMutex.try_lock()) {
     error(Error, Context);
     dumpDIE(DIE, Options.Verbose);
+    ErrorHandlerMutex.unlock();
+  }
 }
 
 ErrorOr<const object::ObjectFile &>
 DwarfLinkerForBinary::loadObject(const DebugMapObject &Obj,
                                  const Triple &Triple) {
   auto ObjectEntry =
       BinHolder.getObjectEntry(Obj.getObjectFilename(), Obj.getTimestamp());
   if (!ObjectEntry) {

 DwarfLinkerForBinary::loadObject(const DebugMapObject &Obj,
                                  const DebugMap &DebugMap,
                                  remarks::RemarkLinker &RL) {
   auto ErrorOrObj = loadObject(Obj, DebugMap.getTriple());
   std::unique_ptr<OutDWARFFile> Res;
 
   if (ErrorOrObj) {
     Res = std::make_unique<OutDWARFFile>(
-        Obj.getObjectFilename(), DWARFContext::create(*ErrorOrObj),
+        Obj.getObjectFilename(),
+        DWARFContext::create(
+            *ErrorOrObj, DWARFContext::ProcessDebugRelocations::Process,
+            nullptr, "",
+            [&](Error Err) {
+              handleAllErrors(std::move(Err), [&](ErrorInfoBase &Info) {
+                reportError(Info.message());
+              });
+            },
+            [&](Error Warning) {
+              handleAllErrors(std::move(Warning), [&](ErrorInfoBase &Info) {
+                reportWarning(Info.message());
+              });
+            }),
         std::make_unique<AddressesMap>(*this, *ErrorOrObj, Obj),
-        Obj.empty() ? Obj.getWarnings() : EmptyWarnings);
+        Obj.empty() ? Obj.getWarnings() : EmptyWarnings,
+        [&](StringRef FileName) { BinHolder.eraseObjectEntry(FileName); });
 
     Error E = RL.link(*ErrorOrObj);
     if (Error NewE = handleErrors(
             std::move(E), [&](std::unique_ptr<FileError> EC) -> Error {
               return remarksErrorHandler(Obj, *this, std::move(EC));
             }))
       return errorToErrorCode(std::move(NewE));
 

 std::optional<int64_t> DwarfLinkerForBinary::AddressManager<AddressesMapBase>::
     getExprOpAddressRelocAdjustment(DWARFUnit &U,
                                     const DWARFExpression::Operation &Op,
                                     uint64_t StartOffset, uint64_t EndOffset) {
   switch (Op.getCode()) {
   default: {
     assert(false && "Specified operation does not have address operand");
   } break;
+  case dwarf::DW_OP_const2u:
   case dwarf::DW_OP_const4u:
   case dwarf::DW_OP_const8u:
+  case dwarf::DW_OP_const2s:
   case dwarf::DW_OP_const4s:
   case dwarf::DW_OP_const8s:
   case dwarf::DW_OP_addr: {
     return hasValidRelocationAt(ValidDebugInfoRelocs, StartOffset, EndOffset);
   } break;
   case dwarf::DW_OP_constx:
   case dwarf::DW_OP_addrx: {
     return hasValidRelocationAt(ValidDebugAddrRelocs, StartOffset, EndOffset);

llvm/tools/llvm-dwarfutil/DebugInfoLinker.cpp

if (std::optional<uint64_t> LowPC =
                          DIE.getDwarfUnit()->getAddressByteSize()))
         // Relocation value for the linked binary is 0.
         return 0;
     }
 
     return std::nullopt;
   }
 
-  std::optional<int64_t> getExprOpAddressRelocAdjustment(
-      DWARFUnit &U, const DWARFExpression::Operation &Op, uint64_t StartOffset,
-      uint64_t EndOffset) override {
+  std::optional<int64_t>
+  getExprOpAddressRelocAdjustment(DWARFUnit &U,
+                                  const DWARFExpression::Operation &Op,
+                                  uint64_t, uint64_t) override {
     switch (Op.getCode()) {
     default: {
       assert(false && "Specified operation does not have address operand");
     } break;
+    case dwarf::DW_OP_const2u:
     case dwarf::DW_OP_const4u:
     case dwarf::DW_OP_const8u:
+    case dwarf::DW_OP_const2s:
     case dwarf::DW_OP_const4s:
     case dwarf::DW_OP_const8s:
     case dwarf::DW_OP_addr: {
       if (!isDeadAddress(Op.getRawOperand(0), U.getVersion(), Opts.Tombstone,
                          U.getAddressByteSize()))
         // Relocation value for the linked binary is 0.
         return 0;
     } break;
static std::string getMessageForDeletedAcceleratorTables(
   Message += "' will be deleted as no accelerator tables are requested";
 
   return Message;
 }
 
 template <typename Linker, typename OutDwarfFile, typename AddressMapBase>
 Error linkDebugInfoImpl(object::ObjectFile &File, const Options &Options,
                         raw_pwrite_stream &OutStream) {
+  std::mutex ErrorHandlerMutex;
+
   auto ReportWarn = [&](const Twine &Message, StringRef Context,
                         const DWARFDie *Die) {
-    warning(Message, Context);
-
-    if (!Options.Verbose || !Die)
+    // FIXME: implement warning logging which does not block other threads.
+    if (!ErrorHandlerMutex.try_lock())
       return;
 
+    warning(Message, Context);
+    if (Options.Verbose && Die) {
       DIDumpOptions DumpOpts;
       DumpOpts.ChildRecurseDepth = 0;
       DumpOpts.Verbose = Options.Verbose;
 
       WithColor::note() << "    in DIE:\n";
       Die->dump(errs(), /*Indent=*/6, DumpOpts);
+    }
+    ErrorHandlerMutex.unlock();
   };
   auto ReportErr = [&](const Twine &Message, StringRef Context,
                        const DWARFDie *) {
+    // FIXME: implement error logging which does not block other threads.
+    if (!ErrorHandlerMutex.try_lock())
+      return;
+
     WithColor::error(errs(), Context) << Message << '\n';
+    ErrorHandlerMutex.unlock();
   };
 
   // Create DWARF linker.
   std::unique_ptr<Linker> DebugInfoLinker =
       Linker::createLinker(ReportErr, ReportWarn);
 
   Triple TargetTriple = File.makeTriple();
   if (Error Err = DebugInfoLinker->createEmitter(
           TargetTriple, Linker::OutputFileType::Object, OutStream))
     return Err;
 
   DebugInfoLinker->setEstimatedObjfilesAmount(1);
   DebugInfoLinker->setNumThreads(Options.NumThreads);
   DebugInfoLinker->setNoODR(!Options.DoODRDeduplication);
   DebugInfoLinker->setVerbosity(Options.Verbose);
   DebugInfoLinker->setUpdateIndexTablesOnly(!Options.DoGarbageCollection);
 
   std::vector<std::unique_ptr<OutDwarfFile>> ObjectsForLinking(1);
   std::vector<std::string> EmptyWarnings;
 
   // Add object files to the DWARFLinker.
-  std::unique_ptr<DWARFContext> Context = DWARFContext::create(File);
+  std::unique_ptr<DWARFContext> Context = DWARFContext::create(
+      File, DWARFContext::ProcessDebugRelocations::Process, nullptr, "",
+      [&](Error Err) {
+        handleAllErrors(std::move(Err), [&](ErrorInfoBase &Info) {
+          ReportErr(Info.message(), "", nullptr);
+        });
+      },
+      [&](Error Warning) {
+        handleAllErrors(std::move(Warning), [&](ErrorInfoBase &Info) {
+          ReportWarn(Info.message(), "", nullptr);
+        });
+      });
   std::unique_ptr<ObjFileAddressMap<AddressMapBase>> AddressesMap(
       std::make_unique<ObjFileAddressMap<AddressMapBase>>(*Context, Options,
                                                           File));
 
   ObjectsForLinking[0] =
       std::make_unique<OutDwarfFile>(File.getFileName(), std::move(Context),
                                      std::move(AddressesMap), EmptyWarnings);
 

llvm/unittests/CodeGen/DwarfStringPoolEntryRefTest.cpp

 
 bool isEntryEqual(const DwarfStringPoolEntry &LHS,
                   const DwarfStringPoolEntry &RHS) {
   return LHS.Symbol == RHS.Symbol && LHS.Offset == RHS.Offset &&
          LHS.Index == RHS.Index;
 }
 
 TEST(DwarfStringPoolEntryRefTest, TestShortEntry) {
-  BumpPtrAllocator Allocator;
-  DwarfStringPoolEntry DwarfEntry1 = {nullptr, 0, 0};
-  StringMapEntry<DwarfStringPoolEntry *> *StringEntry1 =
-      StringMapEntry<DwarfStringPoolEntry *>::create("Key1", Allocator,
-                                                     &DwarfEntry1);
-
-  EXPECT_TRUE(StringEntry1->getKey() == "Key1");
-  EXPECT_TRUE(StringEntry1->second->Symbol == nullptr);
-  EXPECT_TRUE(StringEntry1->second->Offset == 0);
-  EXPECT_TRUE(StringEntry1->second->Index == 0);
+  DwarfStringPoolEntryWithExtString DwarfEntry1 = {{nullptr, 0, 0}, "Key1"};
 
-  DwarfStringPoolEntryRef Ref1(*StringEntry1);
+  DwarfStringPoolEntryRef Ref1(DwarfEntry1);
   EXPECT_TRUE(Ref1.getString() == "Key1");
   EXPECT_TRUE(Ref1.getOffset() == 0);
   EXPECT_TRUE(Ref1.getIndex() == 0);
   EXPECT_TRUE(isEntryEqual(Ref1.getEntry(), DwarfEntry1));
 
-  DwarfStringPoolEntryRef Ref2(*StringEntry1);
+  DwarfStringPoolEntryRef Ref2(DwarfEntry1);
   EXPECT_TRUE(Ref2.getString() == "Key1");
   EXPECT_TRUE(Ref2.getOffset() == 0);
   EXPECT_TRUE(isEntryEqual(Ref2.getEntry(), DwarfEntry1));
   EXPECT_TRUE(Ref1 == Ref2);
   EXPECT_FALSE(Ref1 != Ref2);
 
-  DwarfStringPoolEntry DwarfEntry2 = {nullptr, 0x1000, 1};
-  StringMapEntry<DwarfStringPoolEntry *> *StringEntry2 =
-      StringMapEntry<DwarfStringPoolEntry *>::create("Key2", Allocator,
-                                                     &DwarfEntry2);
-  EXPECT_TRUE(StringEntry2->getKey() == "Key2");
-  EXPECT_TRUE(StringEntry2->second->Symbol == nullptr);
-  EXPECT_TRUE(StringEntry2->second->Offset == 0x1000);
-  EXPECT_TRUE(StringEntry2->second->Index == 1);
+  DwarfStringPoolEntryWithExtString DwarfEntry2 = {{nullptr, 0x1000, 1},
+                                                   "Key2"};
 
-  DwarfStringPoolEntryRef Ref3(*StringEntry2);
+  DwarfStringPoolEntryRef Ref3(DwarfEntry2);
   EXPECT_TRUE(Ref3.getString() == "Key2");
   EXPECT_TRUE(Ref3.getOffset() == 0x1000);
   EXPECT_TRUE(Ref3.getIndex() == 1);
   EXPECT_TRUE(isEntryEqual(Ref3.getEntry(), DwarfEntry2));
   EXPECT_TRUE(Ref1 != Ref3);
 }
 
 TEST(DwarfStringPoolEntryRefTest, CompareFullAndShort) {
   BumpPtrAllocator Allocator;
 
-  DwarfStringPoolEntry DwarfEntry1 = {nullptr, 0, 0};
-  StringMapEntry<DwarfStringPoolEntry *> *StringEntry1 =
-      StringMapEntry<DwarfStringPoolEntry *>::create("Key1", Allocator,
-                                                     &DwarfEntry1);
-  DwarfStringPoolEntryRef Ref1(*StringEntry1);
+  DwarfStringPoolEntryWithExtString DwarfEntry1 = {{nullptr, 0, 0}, "Key1"};
+  DwarfStringPoolEntryRef Ref1(DwarfEntry1);
 
   StringMapEntry<DwarfStringPoolEntry> *StringEntry2 =
       StringMapEntry<DwarfStringPoolEntry>::create(
           "Key1", Allocator, DwarfStringPoolEntry{nullptr, 0, 0});
   DwarfStringPoolEntryRef Ref2(*StringEntry2);
 
   EXPECT_FALSE(Ref1 == Ref2);
 }

llvm/unittests/DWARFLinkerParallel/CMakeLists.txt

 set(LLVM_LINK_COMPONENTS
   DWARFLinkerParallel
   Support
   )
 
 add_llvm_unittest(DWARFLinkerParallelTests
   DWARFLinkerTest.cpp
   StringPoolTest.cpp
-  StringTableTest.cpp
   )
 
 target_link_libraries(DWARFLinkerParallelTests PRIVATE LLVMTestingSupport)
 
 add_dependencies(DWARFLinkerParallelTests intrinsics_gen)

llvm/unittests/DWARFLinkerParallel/StringPoolTest.cpp

TEST(StringPoolTest, TestStringPool) {
   // threads created by ThreadPoolExecutor. Use TaskGroup to run on
   // ThreadPoolExecutor threads.
   parallel::TaskGroup tg;
 
   tg.spawn([&]() {
     std::pair<StringEntry *, bool> Entry = Strings.insert("test");
     EXPECT_TRUE(Entry.second);
     EXPECT_TRUE(Entry.first->getKey() == "test");
-    EXPECT_TRUE(Entry.first->second == nullptr);
 
     StringEntry *EntryPtr = Entry.first;
 
     Entry = Strings.insert("test");
     EXPECT_FALSE(Entry.second);
     EXPECT_TRUE(Entry.first->getKey() == "test");
-    EXPECT_TRUE(Entry.first->second == nullptr);
     EXPECT_TRUE(EntryPtr == Entry.first);
 
     Entry = Strings.insert("test2");
     EXPECT_TRUE(Entry.second);
     EXPECT_TRUE(Entry.first->getKey() == "test2");
-    EXPECT_TRUE(Entry.first->second == nullptr);
     EXPECT_TRUE(EntryPtr != Entry.first);
   });
 }
 
 TEST(StringPoolTest, TestStringPoolParallel) {
   StringPool Strings;
 
   // Add data.
   parallelFor(0, 1000, [&](size_t Idx) {
     std::pair<StringEntry *, bool> Entry = Strings.insert(std::to_string(Idx));
     EXPECT_TRUE(Entry.second);
     EXPECT_TRUE(Entry.first->getKey() == std::to_string(Idx));
-    EXPECT_TRUE(Entry.first->second == nullptr);
   });
 
   // Check data.
   parallelFor(0, 1000, [&](size_t Idx) {
     std::pair<StringEntry *, bool> Entry = Strings.insert(std::to_string(Idx));
     EXPECT_FALSE(Entry.second);
     EXPECT_TRUE(Entry.first->getKey() == std::to_string(Idx));
-    EXPECT_TRUE(Entry.first->second == nullptr);
   });
 }
 
 } // anonymous namespace

llvm/unittests/DWARFLinkerParallel/StringTableTest.cpp

-//===- llvm/unittest/DWARFLinkerParallel/StringTableTest.cpp --------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/DWARFLinkerParallel/StringTable.h"
-#include "llvm/Support/Parallel.h"
-#include "gtest/gtest.h"
-#include <cstdlib>
-
-using namespace llvm;
-using namespace dwarflinker_parallel;
-
-namespace {
-
-TEST(StringPoolTest, TestStringTable) {
-  struct StringDescription {
-    const char *Str = nullptr;
-    uint64_t Idx = 0;
-    uint64_t Offset = 0;
-  };
-
-  SmallVector<StringDescription> InputStrings = {
-      {"first", 0, 0}, {"second", 1, 6}, {"third", 2, 13}};
-
-  StringPool Strings;
-  StringTable OutStrings(Strings, nullptr);
-
-  // StringPool uses PerThreadBumpPtrAllocator which should be accessed from
-  // threads created by ThreadPoolExecutor. Use TaskGroup to run on
-  // ThreadPoolExecutor threads.
-  parallel::TaskGroup tg;
-
-  tg.spawn([&]() {
-    // Check string insertion.
-    StringEntry *FirstPtr = Strings.insert(InputStrings[0].Str).first;
-    StringEntry *SecondPtr = Strings.insert(InputStrings[1].Str).first;
-    StringEntry *ThirdPtr = Strings.insert(InputStrings[2].Str).first;
-
-    FirstPtr = OutStrings.add(FirstPtr);
-    SecondPtr = OutStrings.add(SecondPtr);
-    ThirdPtr = OutStrings.add(ThirdPtr);
-
-    // Check fields of inserted strings.
-    EXPECT_TRUE(FirstPtr->getKey() == InputStrings[0].Str);
-    EXPECT_TRUE(FirstPtr->getValue()->Offset == InputStrings[0].Offset);
-    EXPECT_TRUE(FirstPtr->getValue()->Index == InputStrings[0].Idx);
-
-    EXPECT_TRUE(SecondPtr->getKey() == InputStrings[1].Str);
-    EXPECT_TRUE(SecondPtr->getValue()->Offset == InputStrings[1].Offset);
-    EXPECT_TRUE(SecondPtr->getValue()->Index == InputStrings[1].Idx);
-
-    EXPECT_TRUE(ThirdPtr->getKey() == InputStrings[2].Str);
-    EXPECT_TRUE(ThirdPtr->getValue()->Offset == InputStrings[2].Offset);
-    EXPECT_TRUE(ThirdPtr->getValue()->Index == InputStrings[2].Idx);
-
-    // Check order enumerated strings.
-    uint64_t CurIdx = 0;
-    std::function<void(DwarfStringPoolEntryRef)> checkStr =
-        [&](DwarfStringPoolEntryRef Entry) {
-          EXPECT_TRUE(Entry.getEntry().isIndexed());
-          EXPECT_TRUE(Entry.getIndex() == CurIdx);
-          EXPECT_TRUE(Entry.getOffset() == InputStrings[CurIdx].Offset);
-          EXPECT_TRUE(Entry.getString() == InputStrings[CurIdx].Str);
-
-          CurIdx++;
-        };
-
-    OutStrings.forEach(checkStr);
-  });
-}
-
-TEST(StringPoolTest, TestStringTableWithTranslator) {
-  std::string Word;
-  std::function<StringRef(StringRef)> TranslatorFunc =
-      [&](StringRef InputString) -> StringRef {
-    Word.clear();
-    for (auto Sym : InputString)
-      Word.insert(Word.begin(), Sym);
-    Word += '0';
-    return Word;
-  };
-
-  StringPool Strings;
-  StringTable OutStrings(Strings, TranslatorFunc);
-
-  // StringPool uses PerThreadBumpPtrAllocator which should be accessed from
-  // threads created by ThreadPoolExecutor. Use TaskGroup to run on
-  // ThreadPoolExecutor threads.
-  parallel::TaskGroup tg;
-
-  tg.spawn([&]() {
-    StringEntry *FirstPtr = Strings.insert("first").first;
-    StringEntry *SecondPtr = Strings.insert("second").first;
-    StringEntry *ThirdPtr = Strings.insert("third").first;
-
-    FirstPtr = OutStrings.add(FirstPtr);
-    SecondPtr = OutStrings.add(SecondPtr);
-    ThirdPtr = OutStrings.add(ThirdPtr);
-
-    EXPECT_TRUE(FirstPtr->getKey() == "tsrif0");
-    EXPECT_TRUE(FirstPtr->getValue()->Offset == 0);
-    EXPECT_TRUE(FirstPtr->getValue()->Index == 0);
-
-    EXPECT_TRUE(SecondPtr->getKey() == "dnoces0");
-    EXPECT_TRUE(SecondPtr->getValue()->Offset == 7);
-    EXPECT_TRUE(SecondPtr->getValue()->Index == 1);
-
-    EXPECT_TRUE(ThirdPtr->getKey() == "driht0");
-    EXPECT_TRUE(ThirdPtr->getValue()->Offset == 15);
-    EXPECT_TRUE(ThirdPtr->getValue()->Index == 2);
-  });
-}
-
-} // anonymous namespace