[llvm-dwarfdump] Verify compatible TAG for attributes.

[JDevlieghere]

Summary

Adds a verification that DW_AT_specification and DW_AT_abstract origin
reference a DIE with a compatible tag.

[dblaikie]

lib/DebugInfo/DWARF/DWARFVerifier.cpp

423 ↗

(On Diff #118340)

Can you use DWARFDie::getAttributeValueAsReferencedDie here, perhaps?

test/tools/llvm-dwarfdump/X86/verify_compatible_tags.s

23–24 ↗

(On Diff #118340)

Maybe this should have some more words about which one was expected & which one was actually found? (& maybe dumping whose DIEs or some reference to the DIE so the user knows where to look in the DWARF to find the DIEs in question?)

[JDevlieghere]

• Better error message

[JDevlieghere]

lib/DebugInfo/DWARF/DWARFVerifier.cpp

423 ↗

(On Diff #118340)

Unfortunately not, because this makes use of getUnitForOffset which in turn uses a list of units that isn't build when doing the verification.
Furthermore, this is (probably) slightly more efficient as we already have the attribute value and therefore do not need to do any indirections via the abbrev declaration.

[aprantl]

lib/DebugInfo/DWARF/DWARFVerifier.cpp

422 ↗

(On Diff #118410)

tags

[aprantl]

LGTM with outstanding nitpicks addressed and assuming David is happy with the patch.

lib/DebugInfo/DWARF/DWARFVerifier.cpp

434 ↗

(On Diff #118410)

<< "" ?

[aprantl]

test/tools/llvm-dwarfdump/X86/verify_compatible_tags.s

23 ↗

(On Diff #118410)

can you use CHECK-NEXT here to make the test even stricter?

[JDevlieghere]

• Feedback Adrian

[JDevlieghere]

• Use SmallSet<DWARFDie, 3> (running dsymutil over clang showed that there were never more than 3 elements in the set for valid DWARF).

[JDevlieghere]

Wrong diff got updated, back to previous version.

[JDevlieghere]

Rebase & address Dave's comment (via the mailing list).

[JDevlieghere]

Use separate vectors for compile and type units.

[JDevlieghere]

Rebase

[dblaikie]

llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp

115–119 ↗

(On Diff #165769)

This probably needs to ensure the newly added unit is added such that the vector remains in sorted order (so getUnitForOffset, etc, can rely on that sorted order for offset searches).

It could assert this (if the caller(s) you've added ensure this is true) or do a search/insert to keep things sorted.

Or, if you know you won't be using getUnitForOffset, etc, I guess it doesn't need to. Or if you have a phase where you're building the vector then a separate phase where you're using getUnitForOffset - you could add them all, then sort, then query - that's a bit more efficient that maintaining sorted order when you don't need it.

[JDevlieghere]

Make sure addUnit keeps the DWARFUnitVector sorted.

[JDevlieghere]

llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp

115–119 ↗

(On Diff #165769)

I've updated the patch to keep thing sorted, it seems like the least bug-prone as we keep the invariant. In the verifier we also build and use the vector at the same time, so sorting at the end is tricky (and would require more state if we want to enforce this, making it a less localized approach than simply sorting).

[dblaikie]

llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp

281–282 ↗

(On Diff #166072)

auto UnitUP = llvm::make_unique<DWARFTypeUnit>(...)

perhaps?

(I'd probably even roll it into the next line:

Unit = TypeUnitVector.addUnit(llvm::make_unique<DWARFTypeUnit>(...));

(similarly below for CompileUnit)

461–464 ↗

(On Diff #166072)

Should there be a positive case for tags are the same? (things like a member subprogram - DieTag and RefTag would both be subprogram?) Or a function defined in a namespace (I think GCC puts the declaration in a namespace, the definition at global scope - I forget what Clang does tehre - maybe it doesn't produce a declaration so there's nothing to check there?)

Have you run this check over a large codebase to see that it doesn't produce false positives?

[JDevlieghere]

• Add check for equal tags to cover case where both are subprograms, both are formal params.
• Ran verifier over clang, no errors.
• Ran verifier over GCC generated binary I had laying around, also no errors.

[JDevlieghere]

llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp

461–464 ↗

(On Diff #166072)

We didn't account for the case where the tags were the same, as you suggested. I ran the verifier on a ToT clang and on a gcc-generated binary (some xml lib I had around) and didn't see any false positives.

[dblaikie]

Sounds good - thanks!

[kito-cheng]

llvm/trunk/lib/DebugInfo/DWARF/DWARFVerifier.cpp

463

Hi Jonas:

Compiler will complain about fallthrough here:
lib/DebugInfo/DWARF/DWARFVerifier.cpp:477:5: warning: this statement may fall through [-Wimplicit-fallthrough=]

llvm/trunk/include/llvm/DebugInfo/DWARF/DWARFUnit.h

public:
   /// Read units from a .debug_info.dwo or .debug_types.dwo section.  Calls
   /// made before finishedInfoUnits() are assumed to be for .debug_info.dwo
   /// sections, calls after finishedInfoUnits() are for .debug_types.dwo
   /// sections.  Caller must not mix calls to addUnitsForSection and
   /// addUnitsForDWOSection.
   void addUnitsForDWOSection(DWARFContext &C, const DWARFSection &DWOSection,
                              DWARFSectionKind SectionKind, bool Lazy = false);
 
+  /// Add an existing DWARFUnit to this UnitVector. This is used by the DWARF
+  /// verifier to process unit separately.
+  DWARFUnit *addUnit(std::unique_ptr<DWARFUnit> Unit);
+
   /// Returns number of all units held by this instance.
   unsigned getNumUnits() const { return size(); }
   /// Returns number of units from all .debug_info[.dwo] sections.
   unsigned getNumInfoUnits() const {
     return NumInfoUnits == -1 ? size() : NumInfoUnits;
   }
   /// Returns number of units from all .debug_types[.dwo] sections.
   unsigned getNumTypesUnits() const { return size() - NumInfoUnits; }

llvm/trunk/lib/DebugInfo/DWARF/DWARFUnit.cpp

while (Data.isValidOffset(Offset)) {
     // If parsing failed, we're done with this section.
     if (!U)
       break;
     Offset = U->getNextUnitOffset();
     I = std::next(this->insert(I, std::move(U)));
   }
 }
 
+DWARFUnit *DWARFUnitVector::addUnit(std::unique_ptr<DWARFUnit> Unit) {
+  auto I = std::upper_bound(begin(), end(), Unit,
+                            [](const std::unique_ptr<DWARFUnit> &LHS,
+                               const std::unique_ptr<DWARFUnit> &RHS) {
+                              return LHS->getOffset() < RHS->getOffset();
+                            });
+  return this->insert(I, std::move(Unit))->get();
+}
+
 DWARFUnit *DWARFUnitVector::getUnitForOffset(uint32_t Offset) const {
   auto end = begin() + getNumInfoUnits();
   auto *CU =
       std::upper_bound(begin(), end, Offset,
                        [](uint32_t LHS, const std::unique_ptr<DWARFUnit> &RHS) {
                          return LHS < RHS->getNextUnitOffset();
                        });
   if (CU != end && (*CU)->getOffset() <= Offset)

llvm/trunk/lib/DebugInfo/DWARF/DWARFVerifier.cpp

unsigned DWARFVerifier::verifyUnitSection(const DWARFSection &S,
   const DWARFObject &DObj = DCtx.getDWARFObj();
   DWARFDataExtractor DebugInfoData(DObj, S, DCtx.isLittleEndian(), 0);
   unsigned NumDebugInfoErrors = 0;
   uint32_t OffsetStart = 0, Offset = 0, UnitIdx = 0;
   uint8_t UnitType = 0;
   bool isUnitDWARF64 = false;
   bool isHeaderChainValid = true;
   bool hasDIE = DebugInfoData.isValidOffset(Offset);
-  DWARFUnitVector UnitVector{};
+  DWARFUnitVector TypeUnitVector;
+  DWARFUnitVector CompileUnitVector;
   while (hasDIE) {
     OffsetStart = Offset;
     if (!verifyUnitHeader(DebugInfoData, &Offset, UnitIdx, UnitType,
                           isUnitDWARF64)) {
       isHeaderChainValid = false;
       if (isUnitDWARF64)
         break;
     } else {
       DWARFUnitHeader Header;
       Header.extract(DCtx, DebugInfoData, &OffsetStart, SectionKind);
-      std::unique_ptr<DWARFUnit> Unit;
+      DWARFUnit *Unit;
       switch (UnitType) {
       case dwarf::DW_UT_type:
       case dwarf::DW_UT_split_type: {
-        Unit.reset(new DWARFTypeUnit(
+        Unit = TypeUnitVector.addUnit(llvm::make_unique<DWARFTypeUnit>(
             DCtx, S, Header, DCtx.getDebugAbbrev(), &DObj.getRangeSection(),
             DObj.getStringSection(), DObj.getStringOffsetSection(),
             &DObj.getAppleObjCSection(), DObj.getLineSection(),
-            DCtx.isLittleEndian(), false, UnitVector));
+            DCtx.isLittleEndian(), false, TypeUnitVector));
         break;
       }
       case dwarf::DW_UT_skeleton:
       case dwarf::DW_UT_split_compile:
       case dwarf::DW_UT_compile:
       case dwarf::DW_UT_partial:
       // UnitType = 0 means that we are verifying a compile unit in DWARF v4.
       case 0: {
-        Unit.reset(new DWARFCompileUnit(
+        Unit = CompileUnitVector.addUnit(llvm::make_unique<DWARFCompileUnit>(
             DCtx, S, Header, DCtx.getDebugAbbrev(), &DObj.getRangeSection(),
             DObj.getStringSection(), DObj.getStringOffsetSection(),
             &DObj.getAppleObjCSection(), DObj.getLineSection(),
-            DCtx.isLittleEndian(), false, UnitVector));
+            DCtx.isLittleEndian(), false, CompileUnitVector));
         break;
       }
       default: { llvm_unreachable("Invalid UnitType."); }
       }
       NumDebugInfoErrors += verifyUnitContents(*Unit);
     }
     hasDIE = DebugInfoData.isValidOffset(Offset);
     ++UnitIdx;
if (Optional<ArrayRef<uint8_t>> Expr = AttrValue.Value.getAsBlock()) {
       // Verify location list.
       if (auto DebugLoc = DCtx.getDebugLoc())
         if (auto LocList = DebugLoc->getLocationListAtOffset(*LocOffset))
           for (const auto &Entry : LocList->Entries)
             VerifyLocationExpr({Entry.Loc.data(), Entry.Loc.size()});
     }
     break;
   }
-
+  case DW_AT_specification:
+  case DW_AT_abstract_origin: {
+    if (auto ReferencedDie = Die.getAttributeValueAsReferencedDie(Attr)) {
+      auto DieTag = Die.getTag();
+      auto RefTag = ReferencedDie.getTag();
+      if (DieTag == RefTag)
+        break;
+      if (DieTag == DW_TAG_inlined_subroutine && RefTag == DW_TAG_subprogram)
+        break;
+      if (DieTag == DW_TAG_variable && RefTag == DW_TAG_member)
+        break;
+      ReportError("DIE with tag " + TagString(DieTag) + " has " +
+                  AttributeString(Attr) +
+                  " that points to DIE with "
+                  "incompatible tag " +
+                  TagString(RefTag));
+    }
+  }
   default:
     break;
   }
   return NumErrors;
 }
 
 unsigned DWARFVerifier::verifyDebugInfoForm(const DWARFDie &Die,
                                             DWARFAttribute &AttrValue) {

llvm/trunk/test/tools/llvm-dwarfdump/X86/verify_compatible_tags.s

+# RUN: llvm-mc %s -filetype obj -triple x86_64-apple-darwin -o - \
+# RUN: | not llvm-dwarfdump -v -verify - \
+# RUN: | FileCheck %s
+
+# Source:
+#
+#   void f1() {}
+#   __attribute__((always_inline)) void f2() {
+#     f1();
+#   }
+#   int main() {
+#     f2();
+#   }
+#
+# Compile with:
+#
+#   $ clang -g inlined.c -O0 -S -o inlined.s
+#
+#   Manually patch the DW_AT_abstract_origin to point to the
+#   DW_TAG_base_type and DW_TAG_compile_unit respectively.
+
+# CHECK: error: DIE with tag DW_TAG_subprogram has DW_AT_abstract_origin that points to DIE with incompatible tag DW_TAG_base_type
+# CHECK: DW_TAG_subprogram
+
+# CHECK: error: DIE with tag DW_TAG_inlined_subroutine has DW_AT_abstract_origin that points to DIE with incompatible tag DW_TAG_compile_unit
+# CHECK: DW_TAG_inlined_subroutine
+
+  .section  __TEXT,__text,regular,pure_instructions
+  .macosx_version_min 10, 13
+  .globl  _f1                     ## -- Begin function f1
+  .p2align  4, 0x90
+_f1:                                    ## @f1
+Lfunc_begin0:
+  .file 1 "inlined.c"
+  .loc  1 1 0                   ## inlined.c:1:0
+  .cfi_startproc
+## BB#0:                                ## %entry
+  pushq %rbp
+  .cfi_def_cfa_offset 16
+  .cfi_offset %rbp, -16
+  movq  %rsp, %rbp
+  .cfi_def_cfa_register %rbp
+Ltmp0:
+  .loc  1 1 12 prologue_end     ## inlined.c:1:12
+  popq  %rbp
+  retq
+Ltmp1:
+Lfunc_end0:
+  .cfi_endproc
+                                        ## -- End function
+  .globl  _f2                     ## -- Begin function f2
+  .p2align  4, 0x90
+_f2:                                    ## @f2
+Lfunc_begin1:
+  .loc  1 3 0                   ## inlined.c:3:0
+  .cfi_startproc
+## BB#0:                                ## %entry
+  pushq %rbp
+  .cfi_def_cfa_offset 16
+  .cfi_offset %rbp, -16
+  movq  %rsp, %rbp
+  .cfi_def_cfa_register %rbp
+Ltmp2:
+  .loc  1 4 3 prologue_end      ## inlined.c:4:3
+  callq _f1
+  .loc  1 5 1                   ## inlined.c:5:1
+  popq  %rbp
+  retq
+Ltmp3:
+Lfunc_end1:
+  .cfi_endproc
+                                        ## -- End function
+  .globl  _main                   ## -- Begin function main
+  .p2align  4, 0x90
+_main:                                  ## @main
+Lfunc_begin2:
+  .loc  1 7 0                   ## inlined.c:7:0
+  .cfi_startproc
+## BB#0:                                ## %entry
+  pushq %rbp
+  .cfi_def_cfa_offset 16
+  .cfi_offset %rbp, -16
+  movq  %rsp, %rbp
+  .cfi_def_cfa_register %rbp
+Ltmp4:
+  .loc  1 4 3 prologue_end      ## inlined.c:4:3
+  callq _f1
+  xorl  %eax, %eax
+Ltmp5:
+  .loc  1 9 1                   ## inlined.c:9:1
+  popq  %rbp
+  retq
+Ltmp6:
+Lfunc_end2:
+  .cfi_endproc
+                                        ## -- End function
+  .section  __DWARF,__debug_str,regular,debug
+Linfo_string:
+  .asciz  "clang version 6.0.0 (trunk 315286) (llvm/trunk 315291)" ## string offset=0
+  .asciz  "inlined.c"             ## string offset=55
+  .asciz  "/private/tmp"          ## string offset=65
+  .asciz  "f1"                    ## string offset=78
+  .asciz  "f2"                    ## string offset=81
+  .asciz  "main"                  ## string offset=84
+  .asciz  "int"                   ## string offset=89
+  .section  __DWARF,__debug_abbrev,regular,debug
+Lsection_abbrev:
+  .byte 1                       ## Abbreviation Code
+  .byte 17                      ## DW_TAG_compile_unit
+  .byte 1                       ## DW_CHILDREN_yes
+  .byte 37                      ## DW_AT_producer
+  .byte 14                      ## DW_FORM_strp
+  .byte 19                      ## DW_AT_language
+  .byte 5                       ## DW_FORM_data2
+  .byte 3                       ## DW_AT_name
+  .byte 14                      ## DW_FORM_strp
+  .byte 16                      ## DW_AT_stmt_list
+  .byte 23                      ## DW_FORM_sec_offset
+  .byte 27                      ## DW_AT_comp_dir
+  .byte 14                      ## DW_FORM_strp
+  .byte 17                      ## DW_AT_low_pc
+  .byte 1                       ## DW_FORM_addr
+  .byte 18                      ## DW_AT_high_pc
+  .byte 6                       ## DW_FORM_data4
+  .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 18                      ## DW_AT_high_pc
+  .byte 6                       ## DW_FORM_data4
+  .byte 64                      ## DW_AT_frame_base
+  .byte 24                      ## DW_FORM_exprloc
+  .byte 3                       ## DW_AT_name
+  .byte 14                      ## DW_FORM_strp
+  .byte 58                      ## DW_AT_decl_file
+  .byte 11                      ## DW_FORM_data1
+  .byte 59                      ## DW_AT_decl_line
+  .byte 11                      ## DW_FORM_data1
+  .byte 63                      ## DW_AT_external
+  .byte 25                      ## DW_FORM_flag_present
+  .byte 0                       ## EOM(1)
+  .byte 0                       ## EOM(2)
+  .byte 3                       ## Abbreviation Code
+  .byte 46                      ## DW_TAG_subprogram
+  .byte 0                       ## DW_CHILDREN_no
+  .byte 17                      ## DW_AT_low_pc
+  .byte 1                       ## DW_FORM_addr
+  .byte 18                      ## DW_AT_high_pc
+  .byte 6                       ## DW_FORM_data4
+  .byte 64                      ## DW_AT_frame_base
+  .byte 24                      ## DW_FORM_exprloc
+  .byte 49                      ## DW_AT_abstract_origin
+  .byte 19                      ## DW_FORM_ref4
+  .byte 0                       ## EOM(1)
+  .byte 0                       ## EOM(2)
+  .byte 4                       ## Abbreviation Code
+  .byte 46                      ## DW_TAG_subprogram
+  .byte 0                       ## DW_CHILDREN_no
+  .byte 3                       ## DW_AT_name
+  .byte 14                      ## DW_FORM_strp
+  .byte 58                      ## DW_AT_decl_file
+  .byte 11                      ## DW_FORM_data1
+  .byte 59                      ## DW_AT_decl_line
+  .byte 11                      ## DW_FORM_data1
+  .byte 63                      ## DW_AT_external
+  .byte 25                      ## DW_FORM_flag_present
+  .byte 32                      ## DW_AT_inline
+  .byte 11                      ## DW_FORM_data1
+  .byte 0                       ## EOM(1)
+  .byte 0                       ## EOM(2)
+  .byte 5                       ## Abbreviation Code
+  .byte 46                      ## DW_TAG_subprogram
+  .byte 1                       ## DW_CHILDREN_yes
+  .byte 17                      ## DW_AT_low_pc
+  .byte 1                       ## DW_FORM_addr
+  .byte 18                      ## DW_AT_high_pc
+  .byte 6                       ## DW_FORM_data4
+  .byte 64                      ## DW_AT_frame_base
+  .byte 24                      ## DW_FORM_exprloc
+  .byte 3                       ## DW_AT_name
+  .byte 14                      ## DW_FORM_strp
+  .byte 58                      ## DW_AT_decl_file
+  .byte 11                      ## DW_FORM_data1
+  .byte 59                      ## DW_AT_decl_line
+  .byte 11                      ## DW_FORM_data1
+  .byte 73                      ## DW_AT_type
+  .byte 19                      ## DW_FORM_ref4
+  .byte 63                      ## DW_AT_external
+  .byte 25                      ## DW_FORM_flag_present
+  .byte 0                       ## EOM(1)
+  .byte 0                       ## EOM(2)
+  .byte 6                       ## Abbreviation Code
+  .byte 29                      ## DW_TAG_inlined_subroutine
+  .byte 0                       ## DW_CHILDREN_no
+  .byte 49                      ## DW_AT_abstract_origin
+  .byte 19                      ## DW_FORM_ref4
+  .byte 17                      ## DW_AT_low_pc
+  .byte 1                       ## DW_FORM_addr
+  .byte 18                      ## DW_AT_high_pc
+  .byte 6                       ## DW_FORM_data4
+  .byte 88                      ## DW_AT_call_file
+  .byte 11                      ## DW_FORM_data1
+  .byte 89                      ## DW_AT_call_line
+  .byte 11                      ## DW_FORM_data1
+  .byte 0                       ## EOM(1)
+  .byte 0                       ## EOM(2)
+  .byte 7                       ## Abbreviation Code
+  .byte 36                      ## DW_TAG_base_type
+  .byte 0                       ## DW_CHILDREN_no
+  .byte 3                       ## DW_AT_name
+  .byte 14                      ## DW_FORM_strp
+  .byte 62                      ## DW_AT_encoding
+  .byte 11                      ## DW_FORM_data1
+  .byte 11                      ## DW_AT_byte_size
+  .byte 11                      ## DW_FORM_data1
+  .byte 0                       ## EOM(1)
+  .byte 0                       ## EOM(2)
+  .byte 0                       ## EOM(3)
+  .section  __DWARF,__debug_info,regular,debug
+Lsection_info:
+Lcu_begin0:
+  .long 139                     ## Length of Unit
+  .short  4                       ## DWARF version number
+Lset0 = Lsection_abbrev-Lsection_abbrev ## Offset Into Abbrev. Section
+  .long Lset0
+  .byte 8                       ## Address Size (in bytes)
+  .byte 1                       ## Abbrev [1] 0xb:0x84 DW_TAG_compile_unit
+  .long 0                       ## DW_AT_producer
+  .short  12                      ## DW_AT_language
+  .long 55                      ## DW_AT_name
+Lset1 = Lline_table_start0-Lsection_line ## DW_AT_stmt_list
+  .long Lset1
+  .long 65                      ## DW_AT_comp_dir
+  .quad Lfunc_begin0            ## DW_AT_low_pc
+Lset2 = Lfunc_end2-Lfunc_begin0         ## DW_AT_high_pc
+  .long Lset2
+  .byte 2                       ## Abbrev [2] 0x2a:0x15 DW_TAG_subprogram
+  .quad Lfunc_begin0            ## DW_AT_low_pc
+Lset3 = Lfunc_end0-Lfunc_begin0         ## DW_AT_high_pc
+  .long Lset3
+  .byte 1                       ## DW_AT_frame_base
+  .byte 86
+  .long 78                      ## DW_AT_name
+  .byte 1                       ## DW_AT_decl_file
+  .byte 1                       ## DW_AT_decl_line
+                                        ## DW_AT_external
+  .byte 3                       ## Abbrev [3] 0x3f:0x13 DW_TAG_subprogram
+  .quad Lfunc_begin1            ## DW_AT_low_pc
+Lset4 = Lfunc_end1-Lfunc_begin1         ## DW_AT_high_pc
+  .long Lset4
+  .byte 1                       ## DW_AT_frame_base
+  .byte 86
+  .long 135                     ## DW_AT_abstract_origin
+  .byte 4                       ## Abbrev [4] 0x52:0x8 DW_TAG_subprogram
+  .long 81                      ## DW_AT_name
+  .byte 1                       ## DW_AT_decl_file
+  .byte 2                       ## DW_AT_decl_line
+                                        ## DW_AT_external
+  .byte 1                       ## DW_AT_inline
+  .byte 5                       ## Abbrev [5] 0x5a:0x2d DW_TAG_subprogram
+  .quad Lfunc_begin2            ## DW_AT_low_pc
+Lset5 = Lfunc_end2-Lfunc_begin2         ## DW_AT_high_pc
+  .long Lset5
+  .byte 1                       ## DW_AT_frame_base
+  .byte 86
+  .long 84                      ## DW_AT_name
+  .byte 1                       ## DW_AT_decl_file
+  .byte 6                       ## DW_AT_decl_line
+  .long 135                     ## DW_AT_type
+                                        ## DW_AT_external
+  .byte 6                       ## Abbrev [6] 0x73:0x13 DW_TAG_inlined_subroutine
+  .long 11                      ## DW_AT_abstract_origin
+  .quad Ltmp4                   ## DW_AT_low_pc
+Lset6 = Ltmp5-Ltmp4                     ## DW_AT_high_pc
+  .long Lset6
+  .byte 1                       ## DW_AT_call_file
+  .byte 8                       ## DW_AT_call_line
+  .byte 0                       ## End Of Children Mark
+  .byte 7                       ## Abbrev [7] 0x87:0x7 DW_TAG_base_type
+  .long 89                      ## DW_AT_name
+  .byte 5                       ## DW_AT_encoding
+  .byte 4                       ## DW_AT_byte_size
+  .byte 0                       ## End Of Children Mark
+  .section  __DWARF,__debug_ranges,regular,debug
+Ldebug_range:
+  .section  __DWARF,__debug_macinfo,regular,debug
+Ldebug_macinfo:
+Lcu_macro_begin0:
+  .byte 0                       ## End Of Macro List Mark
+  .section  __DWARF,__apple_names,regular,debug
+Lnames_begin:
+  .long 1212240712              ## Header Magic
+  .short  1                       ## Header Version
+  .short  0                       ## Header Hash Function
+  .long 3                       ## Header Bucket Count
+  .long 3                       ## Header Hash Count
+  .long 12                      ## Header Data Length
+  .long 0                       ## HeaderData Die Offset Base
+  .long 1                       ## HeaderData Atom Count
+  .short  1                       ## DW_ATOM_die_offset
+  .short  6                       ## DW_FORM_data4
+  .long -1                      ## Bucket 0
+  .long 0                       ## Bucket 1
+  .long 2                       ## Bucket 2
+  .long 5863324                 ## Hash in Bucket 1
+  .long 2090499946              ## Hash in Bucket 1
+  .long 5863325                 ## Hash in Bucket 2
+  .long LNames1-Lnames_begin    ## Offset in Bucket 1
+  .long LNames0-Lnames_begin    ## Offset in Bucket 1
+  .long LNames2-Lnames_begin    ## Offset in Bucket 2
+LNames1:
+  .long 78                      ## f1
+  .long 1                       ## Num DIEs
+  .long 42
+  .long 0
+LNames0:
+  .long 84                      ## main
+  .long 1                       ## Num DIEs
+  .long 90
+  .long 0
+LNames2:
+  .long 81                      ## f2
+  .long 2                       ## Num DIEs
+  .long 63
+  .long 115
+  .long 0
+  .section  __DWARF,__apple_objc,regular,debug
+Lobjc_begin:
+  .long 1212240712              ## Header Magic
+  .short  1                       ## Header Version
+  .short  0                       ## Header Hash Function
+  .long 1                       ## Header Bucket Count
+  .long 0                       ## Header Hash Count
+  .long 12                      ## Header Data Length
+  .long 0                       ## HeaderData Die Offset Base
+  .long 1                       ## HeaderData Atom Count
+  .short  1                       ## DW_ATOM_die_offset
+  .short  6                       ## DW_FORM_data4
+  .long -1                      ## Bucket 0
+  .section  __DWARF,__apple_namespac,regular,debug
+Lnamespac_begin:
+  .long 1212240712              ## Header Magic
+  .short  1                       ## Header Version
+  .short  0                       ## Header Hash Function
+  .long 1                       ## Header Bucket Count
+  .long 0                       ## Header Hash Count
+  .long 12                      ## Header Data Length
+  .long 0                       ## HeaderData Die Offset Base
+  .long 1                       ## HeaderData Atom Count
+  .short  1                       ## DW_ATOM_die_offset
+  .short  6                       ## DW_FORM_data4
+  .long -1                      ## Bucket 0
+  .section  __DWARF,__apple_types,regular,debug
+Ltypes_begin:
+  .long 1212240712              ## Header Magic
+  .short  1                       ## Header Version
+  .short  0                       ## Header Hash Function
+  .long 1                       ## Header Bucket Count
+  .long 1                       ## Header Hash Count
+  .long 20                      ## Header Data Length
+  .long 0                       ## HeaderData Die Offset Base
+  .long 3                       ## HeaderData Atom Count
+  .short  1                       ## DW_ATOM_die_offset
+  .short  6                       ## DW_FORM_data4
+  .short  3                       ## DW_ATOM_die_tag
+  .short  5                       ## DW_FORM_data2
+  .short  4                       ## DW_ATOM_type_flags
+  .short  11                      ## DW_FORM_data1
+  .long 0                       ## Bucket 0
+  .long 193495088               ## Hash in Bucket 0
+  .long Ltypes0-Ltypes_begin    ## Offset in Bucket 0
+Ltypes0:
+  .long 89                      ## int
+  .long 1                       ## Num DIEs
+  .long 135
+  .short  36
+  .byte 0
+  .long 0
+
+.subsections_via_symbols
+  .section  __DWARF,__debug_line,regular,debug
+Lsection_line:
+Lline_table_start0: