[BTF] Add BTF DebugInfo

[yonghong-song]

Summary

This patch adds BPF Debug Format (BTF) as a standalone
LLVM debuginfo. The BTF related sections are directly
generated from IR. The BTF debuginfo is generated
only when the compilation target is BPF.

What is BTF?

First, the BPF is a linux kernel virtual machine
and widely used for tracing, networking and security.

https://www.kernel.org/doc/Documentation/networking/filter.txt
https://cilium.readthedocs.io/en/v1.2/bpf/

BTF is the debug info format for BPF, introduced in the below
linux patch

https://github.com/torvalds/linux/commit/69b693f0aefa0ed521e8bd02260523b5ae446ad7#diff-06fb1c8825f653d7e539058b72c83332

in the patch set mentioned in the below lwn article.

https://lwn.net/Articles/752047/

The BTF format is specified in the above github commit.
In summary, its layout looks like

struct btf_header
type subsection (a list of types)
string subsection (a list of strings)

With such information, the kernel and the user space is able to
pretty print a particular bpf map key/value. One possible example below:

Withtout BTF:
  key: [ 0x01, 0x01, 0x00, 0x00 ]
With BTF:
  key: struct t { a : 1; b : 1; c : 0}
where struct is defined as
  struct t { char a; char b; short c; };

How BTF is generated?

Currently, the BTF is generated through pahole.

https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=68645f7facc2eb69d0aeb2dd7d2f0cac0feb4d69

and available in pahole v1.12

https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=4a21c5c8db0fcd2a279d067ecfb731596de822d4

Basically, the bpf program needs to be compiled with -g with
dwarf sections generated. The pahole is enhanced such that
a .BTF section can be generated based on dwarf. This format
of the .BTF section matches the format expected by
the kernel, so a bpf loader can just take the .BTF section
and load it into the kernel.

https://github.com/torvalds/linux/commit/8a138aed4a807ceb143882fb23a423d524dcdb35

The .BTF section layout is also specified in this patch:
with file include/llvm/BinaryFormat/BTF.h.

What use cases this patch tries to address?

Currently, only the bpf instruction stream is required to
pass to the kernel. The kernel verifies it, jits it if configured
to do so, attaches it to a particular kernel attachment point,
and later executes when a particular event happens.

This patch tries to expand BTF to support two more use cases below:

(1). BPF supports subroutine calls.
     During performance analysis, it would be good to
     differentiate which call is hot instead of just
     providing a virtual address. This would require to
     pass a unique identifier for each subroutine to
     the kernel, the subroutine name is a natual choice.
(2). If a particular jitted instruction is hot, we want
     user to know which source line this jitted instruction
     belongs to. This would require the source information
     is available to various profiling tools.

Note that in a single ELF file,

. there may be multiple loadable bpf programs,
. for a particular to-be-loaded bpf instruction stream,
  its instructions may come from multiple PROGBITS sections,
  the bpf loader needs to merge them together to a single
  consecutive insn stream before loading to the kernel.

For example:

section .text: subroutines funcFoo
section _progA: calling funcFoo
section _progB: calling funcFoo

The bpf loader could construct two loadable bpf instruction
streams and load them into the kernel:

. _progA funcFoo
. _progB funcFoo

So per ELF section function offset and instruction offset
will need to be adjusted before passing to the kernel, and
the kernel essentially expect only one code section regardless
of how many in the ELF file.

What do we propose and Why?

To support the above two use cases, we propose to
add an additional section, .BTF.ext, to the ELF file
which is the input of the bpf loader. A different section
is preferred since loader may need to manipulate it before
loading part of its data to the kernel.

The .BTF.ext section has a similar header to the .BTF section
and it contains two subsections for func_info and line_info.

. the func_info maps the func insn byte offset to a func
  type in the .BTF type subsection.
. the line_info maps the insn byte offset to a line info.
. both func_info and line_info subsections are organized
  by ELF PROGBITS AX sections.

pahole is not a good place to implement .BTF.ext as
pahole is mostly for structure hole information and more
importantly, we want to pass the actual code to the kernel.

. bpf program typically is small so storage overhead
  should be small.
. in bpf land, it is totally possible that
  an application loads the bpf program into the
  kernel and then that application quits, so
  holding debug info by the user space application
  is not practical as you may not even know who
  loads this bpf program.
. having source codes directly kept by kernel
  would ease deployment since the original source
  code does not need ship on every hosts and
  kernel-devel package does not need to be
  deployed even if kernel headers are used.

LLVM is a good place to implement.

. The only reliable time to get the source code is
  during compilation time. This will result in both more
  accurate information and easier deployment as
  stated in the above.
. Another consideration is for JIT. The project like bcc
  (https://github.com/iovisor/bcc)
  use MCJIT to compile a C program into bpf insns and
  load them to the kernel. The llvm generated BTF sections
  will be readily available for such cases as well.

Design and implementation of emiting .BTF/.BTF.ext sections

The BTF debuginfo format is defined. Both .BTF and .BTF.ext
sections are generated directly from IR when both
"-target bpf" and "-g" are specified. Note that
dwarf sections are still generated as dwarf is used
by user space tools like llvm-objdump etc. for BPF target.

This patch also contains tests to verify generated
.BTF and .BTF.ext sections for all supported types, func_info
and line_info subsections. The patch is also tested
against linux kernel bpf sample tests and selftests.

Signed-off-by: Yonghong Song <[e-mail]>

[yonghong-song]

change a few struct/func test cases so names are shown as ascii instead of bytes.

[aprantl]

include/llvm/BinaryFormat/BTF.h

47

These names don't follow the LLVM coding guidelines.
Perhaps these enums should have underlying types?
enum : uint32_t or something?

include/llvm/MC/MCObjectFileInfo.h

213

/// BTF-specific sections. (BTF is ...)

392

same as above

lib/CodeGen/AsmPrinter/BTFDebug.cpp

208

There are suspiciously few comments in most of these functions. Is what they are doing really obvious?

420

This function looks like it would fit better in DebugInfoFinder?http://llvm.org/doxygen/classllvm_1_1DebugInfoFinder.html

I would also check how Verifier.cpp does this and whether it could be factored out.

lib/CodeGen/AsmPrinter/BTFDebug.h

120

please add doxygen comments to all member functions that aren't obvious getter/setters and such.

151

This is a little long for an inline definition, perhaps move to .cpp file?

151

doxygen comment?

[yonghong-song]

Fixed various stylish issues pointed out by Adrian.

[yonghong-song]

I did not use DebugInfoFinder or refactor Verifier.cpp to type visiting. There are a couple of reasons for this.

. DebugInfoFinder tries to collect all information for a module and process them together.
. The BTF type processing is very similar to Dwarf and Codeview. 
  In Dwarf, getDIE() is used to check whether a type->DIE has been done or not. If it has,
  that type will not be processed further. 
  Similarly, for CodeView, TypeIndices variable is used to check whether a type -> Index has
  been done or not. If it has, that type will be skipped.
. The current BTF type processing may skip some types during traversal. With DebugInfoFinder approach,
  it will be hard to find which type should be skipped without recursive traversing again.... It may be
  just some space waste, but not ideal.
. With DebugInfoFinder, the type information will need to be collected before the first subprogram
  is processed. Not sure whether all type information is available or not.

I feel refactoring Verifier.cpp to provide a common interface for visiting the type hierarchy is better.
But it looks like complicated and it probably should be done in a different patch. This common
interface could be used by BTF, CodeView and Dwarf as all of them have such a code pattern.
@aprantl what do you think? Maybe I missed something here?

[yonghong-song]

@aprantl @dblaikie Just pinging. Any comments? Thanks!

[aprantl]

@dblaikie / @echristo: Since this is specific to the BTF target, should the code be moved to that target's directory, so clients that don't build the BTF target don't need to pay the code size penalty? Is that something we do / can do at the AsmPrinter level?

[aprantl]

Otherwise I think this is mostly looking good now.

[yonghong-song]

. rebase on latest trunk as there is a conflict and people need to resolve manually otherwise
. fix a small bug related to StringRef usage where StringRef is constructed with a local std::string and after function return local std::string is deallocated, StringRef may not hold correct values.

[yonghong-song]

kernel BTF verifier requires if a FUNC kind is a subprogram, all its arguments must be valid identifier.
Using SP RetainedNodes instead DbgValues so we can get all argument local variables even if they
are not used in the function body. Added a test case to test such a scenario.

[yonghong-song]

the previous revision used SP retained nodes instead of dbgValues. So remove the use of header file DbgEntityHistoryCalculator.h.

[yonghong-song]

If we want to move BTFDebug.h and BTFDebug.cpp to lib/Target/BPF, the header files BTFDebug.h and DebugHandlerBase.h needs to be exposed. In the future, other header files like DbgEntityHistoryCalculator.h may need to be exposed as well as BTF itself may evolve.

@dblaikie @echristo What is your opinion on this patch? Thanks!

[yonghong-song]

emit record size for funcInfo and lineinfo to make funcinfo/lineinfo subsections extensible.

[yonghong-song]

fix a bug in calculating the func_info/debug_info with newly added record size in subsections.

[ast]

Eric, David, any objections to land it now?
It's orthogonal to everything else in the llvm land and we'll keep working on it for foreseeable future.
All comments were addressed and any further refactoring requests can be done later.
I'd like to avoid sitting on it for too long, since a bunch of folks in bpf community are waiting on it.
We have two large sets of kernel patches that depend on it.
We'd like to land llvm bits first, so our kernel test bots can do testing with latest llvm trunk and latest kernel tree asap.

[yonghong-song]

previous we may generate two line_info record for the first insn in a function: the line info based subprogram line and the line info based on the debugloc of the first insn. This is confusing. Now let us just generate one. for the first insn of the function, if the debugloc is available, use that to generate the line info. Otherwise, use the subprogram line to generate a line info record for BTF.

[yonghong-song]

Hi, @echristo, just a ping. Not sure whether you got some time or not to look at this patch. Thanks!

[yonghong-song]

@echristo, just ping. Did you get some time to take a look at this patch? Thanks!

[aprantl]

Meanwhile, have you looked into what it would take to make the BTF part of AsmPrinter link only if the BTF target is being built?

[yonghong-song]

@aprantl I just tried. The following is the change which works by using a stub BPFDebug when BPF target is not specified.

diff --git a/lib/CodeGen/AsmPrinter/BTFDebugStub.cpp b/lib/CodeGen/AsmPrinter/BTFDebugStub.cpp
new file mode 100644
index 00000000000..f27e9c5c75f
--- /dev/null
+++ b/lib/CodeGen/AsmPrinter/BTFDebugStub.cpp
@@ -0,0 +1,46 @@
+//===- llvm/lib/CodeGen/AsmPrinter/BTFDebugStub.cpp -------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file is a stub for BTF generation support. The real implementation
+/// is at BTFDebug.cpp which will be included if BPF target is built.
+///
+//===----------------------------------------------------------------------===//
+
+#include "DebugHandlerBase.h"
+
+namespace llvm {
+
+/// Collect and emit BTF information.
+class BTFDebug : public DebugHandlerBase {
+
+protected:
+  /// Gather pre-function debug information.
+  void beginFunctionImpl(const MachineFunction *MF) override {};
+
+  /// Post process after all instructions in this function are processed.
+  void endFunctionImpl(const MachineFunction *MF) override {};
+
+public:
+  BTFDebug(AsmPrinter *AP);
+
+  void setSymbolSize(const MCSymbol *Symbol, uint64_t Size) override {}
+
+  /// Process beginning of an instruction.
+  void beginInstruction(const MachineInstr *MI) override {
+    DebugHandlerBase::beginInstruction(MI);
+  };
+
+  /// Complete all the types and emit the BTF sections.
+  void endModule() override {};
+};
+
+BTFDebug::BTFDebug(AsmPrinter *AP) : DebugHandlerBase(AP) {}
+
+} // end namespace llvm
diff --git a/lib/CodeGen/AsmPrinter/CMakeLists.txt b/lib/CodeGen/AsmPrinter/CMakeLists.txt
index 24c5d33a120..e12fbf92c77 100644
--- a/lib/CodeGen/AsmPrinter/CMakeLists.txt
+++ b/lib/CodeGen/AsmPrinter/CMakeLists.txt
@@ -1,3 +1,14 @@
+# depends on whether BPF target is built or not
+# eitheer BTFDebug.cpp or BTFDebugStub.cpp is included,
+# but not both.
+set(LLVM_OPTIONAL_SOURCES "BTFDebug.cpp" "BTFDebugStub.cpp")
+list(FIND LLVM_TARGETS_TO_BUILD "BPF" idx)
+if( NOT idx LESS 0 )
+set(BTFDebug_File "BTFDebug.cpp")
+else()
+set(BTFDebug_File "BTFDebugStub.cpp")
+endif()
+
 add_llvm_library(LLVMAsmPrinter
   AccelTable.cpp
   AddressPool.cpp
@@ -24,7 +35,7 @@ add_llvm_library(LLVMAsmPrinter
   WinException.cpp
   CodeViewDebug.cpp
   WasmException.cpp
-  BTFDebug.cpp
+  ${BTFDebug_File}
 
   DEPENDS
   intrinsics_gen

This adds complexity to make file and it adds one more file BTFDebugStub.cpp. I personally think this is not a good approach.
But please let me know what you think and I can implement this if you think it is good.

[aprantl]

In D53736#1300772, @yonghong-song wrote:

@aprantl I just tried. The following is the change which works by using a stub BPFDebug when BPF target is not specified.

diff --git a/lib/CodeGen/AsmPrinter/BTFDebugStub.cpp b/lib/CodeGen/AsmPrinter/BTFDebugStub.cpp
new file mode 100644
index 00000000000..f27e9c5c75f
--- /dev/null
+++ b/lib/CodeGen/AsmPrinter/BTFDebugStub.cpp
@@ -0,0 +1,46 @@
+//===- llvm/lib/CodeGen/AsmPrinter/BTFDebugStub.cpp -------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file is a stub for BTF generation support. The real implementation
+/// is at BTFDebug.cpp which will be included if BPF target is built.
+///
+//===----------------------------------------------------------------------===//
+
+#include "DebugHandlerBase.h"
+
+namespace llvm {
+
+/// Collect and emit BTF information.
+class BTFDebug : public DebugHandlerBase {
+
+protected:
+  /// Gather pre-function debug information.
+  void beginFunctionImpl(const MachineFunction *MF) override {};
+
+  /// Post process after all instructions in this function are processed.
+  void endFunctionImpl(const MachineFunction *MF) override {};
+
+public:
+  BTFDebug(AsmPrinter *AP);
+
+  void setSymbolSize(const MCSymbol *Symbol, uint64_t Size) override {}
+
+  /// Process beginning of an instruction.
+  void beginInstruction(const MachineInstr *MI) override {
+    DebugHandlerBase::beginInstruction(MI);
+  };
+
+  /// Complete all the types and emit the BTF sections.
+  void endModule() override {};
+};
+
+BTFDebug::BTFDebug(AsmPrinter *AP) : DebugHandlerBase(AP) {}
+
+} // end namespace llvm
diff --git a/lib/CodeGen/AsmPrinter/CMakeLists.txt b/lib/CodeGen/AsmPrinter/CMakeLists.txt
index 24c5d33a120..e12fbf92c77 100644
--- a/lib/CodeGen/AsmPrinter/CMakeLists.txt
+++ b/lib/CodeGen/AsmPrinter/CMakeLists.txt
@@ -1,3 +1,14 @@
+# depends on whether BPF target is built or not
+# eitheer BTFDebug.cpp or BTFDebugStub.cpp is included,
+# but not both.
+set(LLVM_OPTIONAL_SOURCES "BTFDebug.cpp" "BTFDebugStub.cpp")
+list(FIND LLVM_TARGETS_TO_BUILD "BPF" idx)
+if( NOT idx LESS 0 )
+set(BTFDebug_File "BTFDebug.cpp")
+else()
+set(BTFDebug_File "BTFDebugStub.cpp")
+endif()
+
 add_llvm_library(LLVMAsmPrinter
   AccelTable.cpp
   AddressPool.cpp
@@ -24,7 +35,7 @@ add_llvm_library(LLVMAsmPrinter
   WinException.cpp
   CodeViewDebug.cpp
   WasmException.cpp
-  BTFDebug.cpp
+  ${BTFDebug_File}
 
   DEPENDS
   intrinsics_gen

This adds complexity to make file and it adds one more file BTFDebugStub.cpp. I personally think this is not a good approach.
But please let me know what you think and I can implement this if you think it is good.

LLVM code size is an actual problem, and since this code only makes sense when the BTF target is present, I think that we should make sure that it's only there when it's needed. Since you don't seem too happy with detecting the BTF target in the AsmPrinter CMake file, perhaps defining the interface in AsmPrinter, moving the implementation to the target directory and having a unique_ptr to the implementation in AsmPrinter would be more elegant?

[yonghong-song]

@aprantl I just prototyped to move BTF generation to BPF backend. This indeed works. The BPF backend
already extends AsmPrinter (in BPFAsmPrinter), which makes changes easier.
The main changes are below:

1. Add an override interface EmitBTF in AsmPrinter and change HandlerInfo to protected as EmitBTF will access this member.

diff --git a/include/llvm/CodeGen/AsmPrinter.h b/include/llvm/CodeGen/AsmPrinter.h
index 14bc0816782..19ff4c2270d 100644

• a/include/llvm/CodeGen/AsmPrinter.h

+++ b/include/llvm/CodeGen/AsmPrinter.h
@@ -137,6 +137,7 @@ private:

static char ID;

+protected:

struct HandlerInfo {
  AsmPrinterHandler *Handler;
  const char *TimerName;

@@ -425,6 +426,11 @@ public:

/// instructions in verbose mode.
virtual void emitImplicitDef(const MachineInstr *MI) const;

+ / Targets can override this to output BTF.
+ / Currently, only BPF target does this.
+ virtual void EmitBTF(const char *DbgTimerName, const char *DbgTimerDescription,
+ const char *GroupName, const char *GroupDescription) {};
+

2. Move BTFDebug.{cpp,h} to lib/Target/BPF directory. And AsmPrinter.cpp change

looks like below:
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 1a5bbd06033..8b1332ba9a5 100644

• a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -12,8 +12,6 @@
===----------------------------------------------------------------------===

#include "llvm/CodeGen/AsmPrinter.h"
-#include "AsmPrinterHandler.h"
-#include "BTFDebug.h"
#include "CodeViewDebug.h"
#include "DwarfDebug.h"
#include "DwarfException.h"
@@ -37,6 +35,7 @@
#include "llvm/BinaryFormat/COFF.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/BinaryFormat/ELF.h"
+#include "llvm/CodeGen/AsmPrinterHandler.h"
#include "llvm/CodeGen/GCMetadata.h"
#include "llvm/CodeGen/GCMetadataPrinter.h"
#include "llvm/CodeGen/GCStrategy.h"
@@ -313,12 +312,8 @@ bool AsmPrinter::doInitialization(Module &M) {

  Handlers.push_back(HandlerInfo(DD, DbgTimerName, DbgTimerDescription,
                                 DWARFGroupName, DWARFGroupDescription));
}

• const Triple &TT = TM.getTargetTriple();
• if (TT.getArch() == Triple::bpfel || TT.getArch() == Triple::bpfeb) {
• Handlers.push_back(HandlerInfo(new BTFDebug(this),
• DbgTimerName, DbgTimerDescription,
• BTFGroupName, BTFGroupDescription));
• }

+
+ EmitBTF(DbgTimerName, DbgTimerDescription, BTFGroupName, BTFGroupDescription);

}
 
switch (MAI->getExceptionHandlingType()) {

3. Since BPFDebug extends DebugHandlerBase, so I have to move lib/CodeGen/AsmPrinter/DebugHandlerBase.h

to include/llvm/CodeGen directory. The same happens lib/CodeGen/AsmPrinter/DbgEntityHistoryCalculator.h
and lib/CodeGen/AsmPrinter/AsmPrinterHandler.h to include/llvm/CodeGen directory.
As a result, a lot of files under lib/CodeGen/AsmPrinter needs to be changed to reflect the new include
location.

4. The BPFAsmPrinter simply implements the override function.

diff --git a/lib/Target/BPF/BPFAsmPrinter.cpp b/lib/Target/BPF/BPFAsmPrinter.cpp
index 705211b486b..6dc25f7d708 100644

• a/lib/Target/BPF/BPFAsmPrinter.cpp

+++ b/lib/Target/BPF/BPFAsmPrinter.cpp
@@ -16,6 +16,7 @@
#include "BPFInstrInfo.h"
#include "BPFMCInstLower.h"
#include "BPFTargetMachine.h"
+#include "BTFDebug.h"
#include "InstPrinter/BPFInstPrinter.h"
#include "llvm/CodeGen/AsmPrinter.h"
#include "llvm/CodeGen/MachineConstantPool.h"
@@ -49,6 +50,8 @@ public:

                           raw_ostream &O) override;
 
void EmitInstruction(const MachineInstr *MI) override;

+ void EmitBTF(const char *DbgTimerName, const char *DbgTimerDescription,
+ const char *GroupName, const char *GroupDescription) override;
};
} // namespace

@@ -131,6 +134,13 @@ void BPFAsmPrinter::EmitInstruction(const MachineInstr *MI) {

EmitToStreamer(*OutStreamer, TmpInst);

}

+void BPFAsmPrinter::EmitBTF(const char *DbgTimerName, const char *DbgTimerDescription,
+ const char *GroupName, const char *GroupDescription) {
+ Handlers.push_back(HandlerInfo(new BTFDebug(this),
+ DbgTimerName, DbgTimerDescription,
+ GroupName, GroupDescription));
+}
+
// Force static initialization.

I think this approach is better. But since it will move a few private header files to public include,
maybe you can comment whether this is okay or not. If it is considered at this point moving these private headers to public headers is premature,
I can implement cmake detection mechanism and we can refactor later if necessary.
Please let me know.

[aprantl]

Since BPFDebug extends DebugHandlerBase, so I have to move lib/CodeGen/AsmPrinter/DebugHandlerBase.h to include/llvm/CodeGen directory. The same happens lib/CodeGen/AsmPrinter/DbgEntityHistoryCalculator.h and lib/CodeGen/AsmPrinter/AsmPrinterHandler.h to include/llvm/CodeGen directory. As a result, a lot of files under lib/CodeGen/AsmPrinter needs to be changed to reflect the new include location.

@dblaikie: any ideas for how to best get the layering right here?

[yonghong-song]

Added BTFDebugStub.cpp and changed CMakefile such that if BPF target is not built, the stub will be used so we can reduce the binary size.
Also added BTF_KIND_FUNC_PROTO per discussion with Edward Cree.

[yonghong-song]

@aprantl @dblaikie I just updated a revision with cmakefile change such that a simple stub in BTFDebugStub.cpp will be included if BPF target is not in build target list. This can be used if you decided that it is not good idea to expose private debuginfo headers at this moment. Thanks!

[MaskRay]

lib/CodeGen/AsmPrinter/BTFDebug.cpp

143

const DINode *

145

cast if you don't think it can be null. LLVM_ENABLE_ASSERTIONS builds have assert() in cast()

196

cast

491

dyn_cast + assert can just be replaced by cast

lib/CodeGen/AsmPrinter/BTFDebug.h

172

StringRef

200

Must these maps be ordered?

203

Consider StringMap

[yonghong-song]

Address Fangrui's comments:

• using "cast" instead of "dyn_cast" and removed a few assertions.
• change argument of addString from std::string to StringRef.
• change std::map to std::unordered_map in several instances as we do not really care its ordering.
• Do not really understand the pros/cons of StringMap vs. std::map, but anyway changed FileContent to use StringMap.

[yonghong-song]

@MaskRay does this patch addressed your comments?
@dblaikie @echristo I currently included BTFDebug.cpp in build only if BPF is in the target list. This is intended to reduce the final binary size. Another approach is to put BTFDebug.cpp in lib/Target/BPF directory. But that involves exposing several private headers in lib/CodeGen/AsmPrinter directory. if the refactoring is anticipated to involve nontrivial work, maybe we can first use the CMakefile tweaking approach and we can have another patch to deal with refactoring? Please let me know your thought. Thanks!

[yonghong-song]

The kernel change has been merged to the kernel bpf-next tree.

https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=740baecd811f8e0be7475e952a0f3174b82d813b

It would be great if we can resolve this patch soon so people can just clone llvm trunk, without applying additional out-of-tree patches, for trying and testing purpose.
Thanks!

[yonghong-song]

Pinging...
@MaskRay could you check whether your comment is properly addressed or not?
@dblaikie could you check whether the current way to handle code size is proper or not and what is the way forward?
Thanks both of you for attention in this patch!

[MaskRay]

Sorry for my slow response. Since this revision proposes to extend the currently supported debug info formats from 2 to 3 (hope I didn't get it wrong), this comes with code size increase and greater maintenance cost (people have to ensure the 3 debug formats continue working when they make changes to the common interface), so please be a bit patient for the slower review process:)
I find that there hasn't been actual discussion on the mailing list https://lists.llvm.org/pipermail/llvm-dev/2018-November/127953.html What about making a follow-up to remind people of that RFC? http://llvmweekly.org/ is also a great place to attract more attention.

Since you are proposing a format similar to CTF (Compact C Type Format), which is used by dtrace. Users on the platforms supporting dtrace may shed some light: Solaris, Mac OS X (since 10.5), FreeBSD (2008), NetBSD (2010), OpenBSD (ongoing since 2016). ctfconvert ctfmerge ctfdump are tools used widely by dtrace but it doesn't seem they need direct support from the compiler.

I'm still learning these stuff to understand better about the whole picture.

Note that dwarf sections are still generated as dwarf is used by user space tools like llvm-objdump etc. for BPF target.

If it is the case, it seems there is no size benefit of object files. I also wonder if https://facebookmicrosites.github.io/bpf/blog/2018/11/14/btf-enhancement.html is related to this revision. That article compares the sizes of BTF and DWARF.
BTF type descriptors does not seem to improve much compared with DWARF, but the deduplicated result is impressive (137x reduction).
I am not an expert on DWARF but I have a feeling that we can probably get a similar reduction rate by leveraging a similar technique to deduplicate DWARF. (For the pass 2 mentioned in that article I think it is a form of DFA minimalization)

[ast]

In D53736#1307616, @MaskRay wrote:

I find that there hasn't been actual discussion on the mailing list

at this point we're no longer looking for feedback on the format itself.
Since BTF already ships as part of linux kernel we cannot change the core format anymore.
Only future BTF extensions are up for discussion.
If you're interested in participating I suggest to subscribe to netdev mailing list.
That's where any BTF/BPF discussions were and will be happening.

BTF type descriptors does not seem to improve much compared with DWARF, but the deduplicated result is impressive (137x reduction).

BTF is tightly coupled with BPF ISA. It's not a traditional debug format like dwarf and not like Solari's CTF.
Linux kernel loads the BTF description and verifies it, since it's about to start using BTF for _safety_ decisions.
It's not debug-info only format.

The latest version of pahole already can convert dwarf to BTF.
But we need tight integration of BTF with llvm's BPF backend to be able to provide func_info and line_info directly into .BTF and .BTF.ext sections
(in this patch set) and for symbolic struct field references (future work).

We don't expect BTF to be used with anything but BPF ISA.

[yonghong-song]

Thanks for the review! A few comments for some of your concerns.

I find that there hasn't been actual discussion on the mailing list https://lists.llvm.org/pipermail/llvm-dev/2018-November/127953.html What about making a follow-up to remind people of that RFC? http://llvmweekly.org/ is also a great place to attract more attention.

This is regarding to the format (using auto vs. using explicit type). I do not have a strong preference on this and I just follow some general guideline e.g., using it in iterators, using it if it would just repeat the same already-appeared type name, using a particular "auto" usage pattern just because somebody else already used it that way during my code study.... Let me know what I need to change in this regard.

I'm still learning these stuff to understand better about the whole picture.

The whole BPF and BTF discussion happens in netdev mailing list https://www.spinics.net/lists/netdev/. You are more than welcome to participate in the discussion. The commit message of this patch provided some limited information about what is BTF and why we want to implement in LLVM.

Note that dwarf sections are still generated as dwarf is used by user space tools like llvm-objdump etc. for BPF target.

The size benefit is not our goal. As stated in commit message, dwarf is used for user space application and BTF is used for kernel.
The size benefit you mentioned in https://facebookmicrosites.github.io/bpf/blog/2018/11/14/btf-enhancement.html is part of work
for compile-once run-everywhere bpf program, presented at linux plumbers conference 2018.
(http://vger.kernel.org/lpc-bpf.html, see the slide under "compile-once run-everywhere BPF program).

[yonghong-song]

@aprantl @echristo @dblaikie Since Adrian has reviewed the patch extensively and the only remaining issue is for possible refactoring and there is no other change request, I would like to merge the patch within a few days. Please do voice out if you have any further change requests. After the merge, I will file a RFE in bugzilla for possible refactoring work so we do not lose track of it. Thanks!

[yonghong-song]

The patch has been reverted.

[yonghong-song]

The previous brief commit (reverted minutes later) shows some compilation failures with the patch.
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/40411
The reason is I implemented in a simpler BTFDebug class in BTFDebugStub.cpp which causing mangled name slightly different between BTFDebugStub.cpp and AsmPrinter.cpp.
This new updated patch fixed the issue and now it builds properly on x86 only platform with the failed test case configuration.

[yonghong-song]

• skip empty inline asm instruction when generating line info.
• implement new mechanism for bitfield described at kernel patch set https://www.spinics.net/lists/netdev/msg540044.html This removed the old implementation marked with FIXME.

[yonghong-song]

In one of my earlier comments, I mentioned it is possible to push the implementation into BPF target directory with the need
moving three private headers to include/llvm/CodeGen directory.
I did not get opinion whether that implementation is preferred or not, but I feel that maybe it is a good idea just to go ahead
with a diff which may facilitate discussion and move review/discussion faster.
I created another diff, https://reviews.llvm.org/D55752, which did this implementation.

[yonghong-song]

@echristo @aprantl @dblaikie This patch has stuck in this state for more than one month and did not make progress.
I have suggested a possible way to move some header files to include directory and then we will be
able to move BTFDebug.{cpp,h} under BPF directory. I have implemented this approach with the
following three patches for easy to see pro and cons of two approaches:

(1) https://reviews.llvm.org/D55755, moving header files
(2) https://reviews.llvm.org/D55756, changes some fields from private to protected
(3) https://reviews.llvm.org/D55752, changes only under target BPF

The new patch series tried to minimize the changes outside the BPF target.
I will really appreciate if you can timely review this patch and related other "competing" patches.
Thanks!

[yonghong-song]

The alternative method (put most of implementation under lib/Target/BPF with slight refactoring at the core) is used. Abandon this one.

include/llvm/BinaryFormat/BTF.h

+//===-- llvm/BinaryFormat/BTF.h ---------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file contains the layout of .BTF and .BTF.ext ELF sections.
+///
+/// The binary layout for .BTF section:
+///   struct Header
+///   Type and Str subsections
+/// The Type subsection is a collection of types with type id starting with 1.
+/// The Str subsection is simply a collection of strings.
+///
+/// The binary layout for .BTF.ext section:
+///   struct ExtHeader
+///   FuncInfo and LineInfo subsections
+/// The FuncInfo subsection is defined as below:
+///   BTFFuncInfo Size
+///   struct SecFuncInfo for ELF section #1
+///   A number of struct BPFFuncInfo for ELF section #1
+///   struct SecFuncInfo for ELF section #2
+///   A number of struct BPFFuncInfo for ELF section #2
+///   ...
+/// The LineInfo subsection is defined as below:
+///   BPFLineInfo Size
+///   struct SecLineInfo for ELF section #1
+///   A number of struct BPFLineInfo for ELF section #1
+///   struct SecLineInfo for ELF section #2
+///   A number of struct BPFLineInfo for ELF section #2
+///   ...
+///
+/// The section formats are also defined at
+///    https://github.com/torvalds/linux/blob/master/include/uapi/linux/btf.h
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_BINARYFORMAT_BTF_H
+#define LLVM_BINARYFORMAT_BTF_H
+
+namespace llvm {
+namespace BTF {
+
+enum : uint32_t { MAGIC = 0xeB9F, VERSION = 1 };
+
+/// Sizes in bytes of various things in the BTF format.
+enum {
+  HeaderSize = 24,
+  ExtHeaderSize = 24,
+  CommonTypeSize = 12,
+  BTFArraySize = 12,
+  BTFEnumSize = 8,
+  BTFMemberSize = 12,
+  BTFParamSize = 8,
+  SecFuncInfoSize = 8,
+  SecLineInfoSize = 8,
+  BPFFuncInfoSize = 8,
+  BPFLineInfoSize = 16
+};
+
+/// The .BTF section header definition.
+struct Header {
+  uint16_t Magic;  ///< Magic value
+  uint8_t Version; ///< Version number
+  uint8_t Flags;   ///< Extra flags
+  uint32_t HdrLen; ///< Length of this header
+
+  /// All offsets are in bytes relative to the end of this header.
+  uint32_t TypeOff; ///< Offset of type section
+  uint32_t TypeLen; ///< Length of type section
+  uint32_t StrOff;  ///< Offset of string section
+  uint32_t StrLen;  ///< Length of string section
+};
+
+enum : uint32_t {
+  MAX_TYPE = 0xffff,        ///< Max # of type identifier
+  MAX_NAME_OFFSET = 0xffff, ///< Max offset into the string section
+  MAX_VLEN = 0xffff         ///< Max # of struct/union/enum members or func args
+};
+
+enum TypeKinds : uint8_t {
+#define HANDLE_BTF_KIND(ID, NAME) BTF_KIND_##NAME = ID,
+#include "llvm/BinaryFormat/BTF.def"
+};
+
+/// The BTF common type definition. Different kinds may have
+/// additional information after this structure data.
+struct CommonType {
+  /// Type name offset in the string table.
+  uint32_t NameOff;
+
+  /// "Info" bits arrangement:
+  /// Bits  0-15: vlen (e.g. # of struct's members)
+  /// Bits 16-23: unused
+  /// Bits 24-27: kind (e.g. int, ptr, array...etc)
+  /// Bits 28-30: unused
+  /// Bit     31: kind_flag, currently used by
+  ///             struct, union and fwd
+  uint32_t Info;
+
+  /// "Size" is used by INT, ENUM, STRUCT and UNION.
+  /// "Size" tells the size of the type it is describing.
+  ///
+  /// "Type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,
+  /// FUNC and FUNC_PROTO.
+  /// "Type" is a type_id referring to another type.
+  union {
+    uint32_t Size;
+    uint32_t Type;
+  };
+};
+
+// For some specific BTF_KIND, "struct CommonType" is immediately
+// followed by extra data.
+
+// BTF_KIND_INT is followed by a u32 and the following
+// is the 32 bits arrangement:
+// BTF_INT_ENCODING(VAL) : (((VAL) & 0x0f000000) >> 24)
+// BTF_INT_OFFSET(VAL) : (((VAL & 0x00ff0000)) >> 16)
+// BTF_INT_BITS(VAL) : ((VAL) & 0x000000ff)
+
+/// Attributes stored in the INT_ENCODING.
+enum : uint8_t { INT_SIGNED = (1 << 0), INT_CHAR = (1 << 1), INT_BOOL = (1 << 2) };
+
+/// BTF_KIND_ENUM is followed by multiple "struct BTFEnum".
+/// The exact number of btf_enum is stored in the vlen (of the
+/// info in "struct CommonType").
+struct BTFEnum {
+  uint32_t NameOff; ///< Enum name offset in the string table
+  int32_t Val;      ///< Enum member value
+};
+
+/// BTF_KIND_ARRAY is followed by one "struct BTFArray".
+struct BTFArray {
+  uint32_t ElemType;  ///< Element type
+  uint32_t IndexType; ///< Index type
+  uint32_t Nelems;    ///< Number of elements for this array
+};
+
+/// BTF_KIND_STRUCT and BTF_KIND_UNION are followed
+/// by multiple "struct BTFMember".  The exact number
+/// of BTFMember is stored in the vlen (of the info in
+/// "struct CommonType").
+///
+/// If the struct/union contains any bitfield member,
+/// the Offset below represents BitOffset (bits 0 - 23)
+/// and BitFieldSize(bits 24 - 31) with BitFieldSize = 0
+/// for non bitfield members. Otherwise, the Offset
+/// represents the BitOffset.
+struct BTFMember {
+  uint32_t NameOff; ///< Member name offset in the string table
+  uint32_t Type;    ///< Member type
+  uint32_t Offset;  ///< BitOffset or BitOffset+BitFieldSize
+};
+
+/// BTF_KIND_FUNC_PROTO are followed by multiple "struct BTFParam".
+/// The exist number of BTFParam is stored in the vlen (of the info
+/// in "struct CommonType").
+struct BTFParam {
+  uint32_t NameOff;
+  uint32_t Type;
+};
+
+/// The .BTF.ext section header definition.
+struct ExtHeader {
+  uint16_t Magic;
+  uint8_t Version;
+  uint8_t Flags;
+  uint32_t HdrLen;
+
+  uint32_t FuncInfoOff; ///< Offset of func info section
+  uint32_t FuncInfoLen; ///< Length of func info section
+  uint32_t LineInfoOff; ///< Offset of line info section
+  uint32_t LineInfoLen; ///< Length of line info section
+};
+
+/// Specifying one function info.
+struct BPFFuncInfo {
+  uint32_t InsnOffset; ///< Byte offset in the section
+  uint32_t TypeId;     ///< Type id referring to .BTF type section
+};
+
+/// Specifying function info's in one section.
+struct SecFuncInfo {
+  uint32_t SecNameOff;  ///< Section name index in the .BTF string table
+  uint32_t NumFuncInfo; ///< Number of func info's in this section
+};
+
+/// Specifying one line info.
+struct BPFLineInfo {
+  uint32_t InsnOffset;  ///< Byte offset in this section
+  uint32_t FileNameOff; ///< File name index in the .BTF string table
+  uint32_t LineOff;     ///< Line index in the .BTF string table
+  uint32_t LineCol;     ///< Line num: line_col >> 10,
+                        ///  col num: line_col & 0x3ff
+};
+
+/// Specifying line info's in one section.
+struct SecLineInfo {
+  uint32_t SecNameOff;  ///< Section name index in the .BTF string tble
+  uint32_t NumLineInfo; ///< Number of line info's in this section
+};
+
+} // End namespace BTF.
+} // End namespace llvm.
+
+#endif

include/llvm/BinaryFormat/BTF.def

+//===- llvm/BinaryFormat/BTF.def - BTF definitions --------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Macros for BTF.
+//
+//===----------------------------------------------------------------------===//
+
+#if !defined(HANDLE_BTF_KIND)
+#error "Missing macro definition of HANDLE_BTF_*"
+#endif
+
+HANDLE_BTF_KIND(0, UNKN)
+HANDLE_BTF_KIND(1, INT)
+HANDLE_BTF_KIND(2, PTR)
+HANDLE_BTF_KIND(3, ARRAY)
+HANDLE_BTF_KIND(4, STRUCT)
+HANDLE_BTF_KIND(5, UNION)
+HANDLE_BTF_KIND(6, ENUM)
+HANDLE_BTF_KIND(7, FWD)
+HANDLE_BTF_KIND(8, TYPEDEF)
+HANDLE_BTF_KIND(9, VOLATILE)
+HANDLE_BTF_KIND(10, CONST)
+HANDLE_BTF_KIND(11, RESTRICT)
+HANDLE_BTF_KIND(12, FUNC)
+HANDLE_BTF_KIND(13, FUNC_PROTO)
+
+#undef HANDLE_BTF_KIND

include/llvm/MC/MCObjectFileInfo.h

protected:
 
   /// COFF specific sections.
   MCSection *DrectveSection;
   MCSection *PDataSection;
   MCSection *XDataSection;
   MCSection *SXDataSection;
   MCSection *GFIDsSection;
 
+  /// BTF-specific sections. BTF stands for BPF Type Format which is
+  /// designed for BPF target and consumed by BPF loader and
+  /// the kernel.
+  /// @{
+  MCSection *BTFSection;
+  MCSection *BTFExtSection;
+  /// @}
+
 public:
   void InitMCObjectFileInfo(const Triple &TT, bool PIC, MCContext &ctx,
                             bool LargeCodeModel = false);
 
   bool getSupportsWeakOmittedEHFrame() const {
     return SupportsWeakOmittedEHFrame;
   }
   bool getSupportsCompactUnwindWithoutEHFrame() const {
public:
   MCSection *getXDataSection() const { return XDataSection; }
   MCSection *getSXDataSection() const { return SXDataSection; }
   MCSection *getGFIDsSection() const { return GFIDsSection; }
 
   MCSection *getEHFrameSection() {
     return EHFrameSection;
   }
 
+  // BTF specific sections.
+  /// @{
+  MCSection *getBTFSection() const { return BTFSection; }
+  MCSection *getBTFExtSection() const { return BTFExtSection; }
+  /// @}
+
   enum Environment { IsMachO, IsELF, IsCOFF, IsWasm };
   Environment getObjectFileType() const { return Env; }
 
   bool isPositionIndependent() const { return PositionIndependent; }
 
 private:
   Environment Env;
   bool PositionIndependent;

lib/CodeGen/AsmPrinter/AsmPrinter.cpp

 //===- AsmPrinter.cpp - Common AsmPrinter code ----------------------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the AsmPrinter class.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "AsmPrinterHandler.h"
+#include "BTFDebug.h"
 #include "CodeViewDebug.h"
 #include "DwarfDebug.h"
 #include "DwarfException.h"
 #include "WasmException.h"
 #include "WinCFGuard.h"
 #include "WinException.h"
 #include "llvm/ADT/APFloat.h"
 #include "llvm/ADT/APInt.h"

 static const char *const DbgTimerDescription = "Debug Info Emission";
 static const char *const EHTimerName = "write_exception";
 static const char *const EHTimerDescription = "DWARF Exception Writer";
 static const char *const CFGuardName = "Control Flow Guard";
 static const char *const CFGuardDescription = "Control Flow Guard Tables";
 static const char *const CodeViewLineTablesGroupName = "linetables";
 static const char *const CodeViewLineTablesGroupDescription =
   "CodeView Line Tables";
+static const char *const BTFGroupName = "BTF";
+static const char *const BTFGroupDescription = "BTF Emission";
 
 STATISTIC(EmittedInsts, "Number of machine instrs printed");
 
 static cl::opt<bool>
     PrintSchedule("print-schedule", cl::Hidden, cl::init(false),
                   cl::desc("Print 'sched: [latency:throughput]' in .s output"));
 
 char AsmPrinter::ID = 0;
if (EmitCodeView && TM.getTargetTriple().isOSWindows()) {
                                      CodeViewLineTablesGroupDescription));
     }
     if (!EmitCodeView || MMI->getModule()->getDwarfVersion()) {
       DD = new DwarfDebug(this, &M);
       DD->beginModule();
       Handlers.push_back(HandlerInfo(DD, DbgTimerName, DbgTimerDescription,
                                      DWARFGroupName, DWARFGroupDescription));
     }
+    const Triple &TT = TM.getTargetTriple();
+    if (TT.getArch() == Triple::bpfel || TT.getArch() == Triple::bpfeb) {
+      Handlers.push_back(HandlerInfo(new BTFDebug(this),
+                                     DbgTimerName, DbgTimerDescription,
+                                     BTFGroupName, BTFGroupDescription));
+    }
   }
 
   switch (MAI->getExceptionHandlingType()) {
   case ExceptionHandling::SjLj:
   case ExceptionHandling::DwarfCFI:
   case ExceptionHandling::ARM:
     isCFIMoveForDebugging = true;
     if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)

lib/CodeGen/AsmPrinter/BTFDebug.h

+//===- llvm/lib/CodeGen/AsmPrinter/BTFDebug.h -------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file contains support for writing BTF debug info.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_CODEGEN_ASMPRINTER_BTFDEBUG_H
+#define LLVM_LIB_CODEGEN_ASMPRINTER_BTFDEBUG_H
+
+#include "DebugHandlerBase.h"
+#include "llvm/ADT/StringMap.h"
+#include "llvm/BinaryFormat/BTF.h"
+#include <unordered_map>
+
+namespace llvm {
+
+class AsmPrinter;
+class BTFDebug;
+class DIType;
+class MCStreamer;
+class MCSymbol;
+class MachineFunction;
+
+/// The base class for BTF type generation.
+class BTFTypeBase {
+protected:
+  uint8_t Kind;
+  uint32_t Id;
+  struct BTF::CommonType BTFType;
+
+public:
+  virtual ~BTFTypeBase() = default;
+  void setId(uint32_t Id) { this->Id = Id; }
+  uint32_t getId() { return Id; }
+  uint32_t roundupToBytes(uint32_t NumBits) { return (NumBits + 7) >> 3; }
+  /// Get the size of this BTF type entry.
+  virtual uint32_t getSize() { return BTF::CommonTypeSize; }
+  /// Complete BTF type generation after all related DebugInfo types
+  /// have been visited so their BTF type id's are available
+  /// for cross referece.
+  virtual void completeType(BTFDebug &BDebug) {}
+  /// Emit types for this BTF type entry.
+  virtual void emitType(MCStreamer &OS);
+};
+
+/// Handle several derived types include pointer, const,
+/// volatile, typedef and restrict.
+class BTFTypeDerived : public BTFTypeBase {
+  const DIDerivedType *DTy;
+
+public:
+  BTFTypeDerived(const DIDerivedType *Ty, unsigned Tag);
+  void completeType(BTFDebug &BDebug);
+  void emitType(MCStreamer &OS);
+};
+
+/// Handle struct or union forward declaration.
+class BTFTypeFwd : public BTFTypeBase {
+  StringRef Name;
+
+public:
+  BTFTypeFwd(StringRef Name, bool IsUnion);
+  void completeType(BTFDebug &BDebug);
+  void emitType(MCStreamer &OS);
+};
+
+/// Handle int type.
+class BTFTypeInt : public BTFTypeBase {
+  StringRef Name;
+  uint32_t IntVal; ///< Encoding, offset, bits
+
+public:
+  BTFTypeInt(uint32_t Encoding, uint32_t SizeInBits, uint32_t OffsetInBits,
+             StringRef TypeName);
+  uint32_t getSize() { return BTFTypeBase::getSize() + sizeof(uint32_t); }
+  void completeType(BTFDebug &BDebug);
+  void emitType(MCStreamer &OS);
+};
+
+/// Handle enumerate type.
+class BTFTypeEnum : public BTFTypeBase {
+  const DICompositeType *ETy;
+  std::vector<struct BTF::BTFEnum> EnumValues;
+
+public:
+  BTFTypeEnum(const DICompositeType *ETy, uint32_t NumValues);
+  uint32_t getSize() {
+    return BTFTypeBase::getSize() + EnumValues.size() * BTF::BTFEnumSize;
+  }
+  void completeType(BTFDebug &BDebug);
+  void emitType(MCStreamer &OS);
+};
+
+/// Handle array type.
+class BTFTypeArray : public BTFTypeBase {
+  const DICompositeType *ATy;
+  struct BTF::BTFArray ArrayInfo;
+
+public:
+  BTFTypeArray(const DICompositeType *ATy);
+  uint32_t getSize() { return BTFTypeBase::getSize() + BTF::BTFArraySize; }
+  void completeType(BTFDebug &BDebug);
+  void emitType(MCStreamer &OS);
+};
+
+/// Handle struct/union type.
+class BTFTypeStruct : public BTFTypeBase {
+  const DICompositeType *STy;
+  bool HasBitField;
+  std::vector<struct BTF::BTFMember> Members;
+
+public:
+  BTFTypeStruct(const DICompositeType *STy, bool IsStruct, bool HasBitField,
+                uint32_t NumMembers);
+  uint32_t getSize() {
+    return BTFTypeBase::getSize() + Members.size() * BTF::BTFMemberSize;
+  }
+  void completeType(BTFDebug &BDebug);
+  void emitType(MCStreamer &OS);
+};
+
+/// Handle function pointer.
+class BTFTypeFuncProto : public BTFTypeBase {
+  const DISubroutineType *STy;
+  std::unordered_map<uint32_t, StringRef> FuncArgNames;
+  std::vector<struct BTF::BTFParam> Parameters;
+
+public:
+  BTFTypeFuncProto(const DISubroutineType *STy, uint32_t NumParams,
+                   const std::unordered_map<uint32_t, StringRef> &FuncArgNames);
+  uint32_t getSize() {
+    return BTFTypeBase::getSize() + Parameters.size() * BTF::BTFParamSize;
+  }
+  void completeType(BTFDebug &BDebug);
+  void emitType(MCStreamer &OS);
+};
+
+/// Handle subprogram
+class BTFTypeFunc : public BTFTypeBase {
+  StringRef Name;
+
+public:
+  BTFTypeFunc(StringRef FuncName, uint32_t ProtoTypeId);
+  uint32_t getSize() { return BTFTypeBase::getSize(); }
+  void completeType(BTFDebug &BDebug);
+  void emitType(MCStreamer &OS);
+};
+
+/// String table.
+class BTFStringTable {
+  /// String table size in bytes.
+  uint32_t Size;
+  /// A mapping from string table offset to the index
+  /// of the Table. It is used to avoid putting
+  /// duplicated strings in the table.
+  std::unordered_map<uint32_t, uint32_t> OffsetToIdMap;
+  /// A vector of strings to represent the string table.
+  std::vector<std::string> Table;
+
+public:
+  BTFStringTable() : Size(0) {}
+  uint32_t getSize() { return Size; }
+  std::vector<std::string> &getTable() { return Table; }
+  /// Add a string to the string table and returns its offset
+  /// in the table.
+  uint32_t addString(StringRef S);
+};
+
+/// Represent one func and its type id.
+struct BTFFuncInfo {
+  const MCSymbol *Label; ///< Func MCSymbol
+  uint32_t TypeId;       ///< Type id referring to .BTF type section
+};
+
+/// Represent one line info.
+struct BTFLineInfo {
+  MCSymbol *Label;      ///< MCSymbol identifying insn for the lineinfo
+  uint32_t FileNameOff; ///< file name offset in the .BTF string table
+  uint32_t LineOff;     ///< line offset in the .BTF string table
+  uint32_t LineNum;     ///< the line number
+  uint32_t ColumnNum;   ///< the column number
+};
+
+/// Collect and emit BTF information.
+class BTFDebug : public DebugHandlerBase {
+  MCStreamer &OS;
+  bool SkipInstruction;
+  bool LineInfoGenerated;
+  uint32_t SecNameOff;
+  uint32_t ArrayIndexTypeId;
+  BTFStringTable StringTable;
+  std::vector<std::unique_ptr<BTFTypeBase>> TypeEntries;
+  std::unordered_map<const DIType *, uint32_t> DIToIdMap;
+  std::unordered_map<uint32_t, std::vector<BTFFuncInfo>> FuncInfoTable;
+  std::unordered_map<uint32_t, std::vector<BTFLineInfo>> LineInfoTable;
+  StringMap<std::vector<std::string>> FileContent;
+
+  /// Add types to TypeEntries.
+  /// @{
+  /// Add types to TypeEntries and DIToIdMap.
+  void addType(std::unique_ptr<BTFTypeBase> TypeEntry, const DIType *Ty);
+  /// Add types to TypeEntries only and return type id.
+  uint32_t addType(std::unique_ptr<BTFTypeBase> TypeEntry);
+  /// @}
+
+  /// IR type visiting functions.
+  /// @{
+  void visitTypeEntry(const DIType *Ty);
+  void visitBasicType(const DIBasicType *BTy);
+  void visitSubroutineType(
+      const DISubroutineType *STy, bool ForSubprog,
+      const std::unordered_map<uint32_t, StringRef> &FuncArgNames,
+      uint32_t &TypeId);
+  void visitFwdDeclType(const DICompositeType *CTy, bool IsUnion);
+  void visitCompositeType(const DICompositeType *CTy);
+  void visitStructType(const DICompositeType *STy, bool IsStruct);
+  void visitArrayType(const DICompositeType *ATy);
+  void visitEnumType(const DICompositeType *ETy);
+  void visitDerivedType(const DIDerivedType *DTy);
+  /// @}
+
+  /// Get the file content for the subprogram. Certain lines of the file
+  /// later may be put into string table and referenced by line info.
+  std::string populateFileContent(const DISubprogram *SP);
+
+  /// Construct a line info.
+  void constructLineInfo(const DISubprogram *SP, MCSymbol *Label, uint32_t Line,
+                         uint32_t Column);
+
+  /// Emit common header of .BTF and .BTF.ext sections.
+  void emitCommonHeader();
+
+  /// Emit the .BTF section.
+  void emitBTFSection();
+
+  /// Emit the .BTF.ext section.
+  void emitBTFExtSection();
+
+protected:
+  /// Gather pre-function debug information.
+  void beginFunctionImpl(const MachineFunction *MF) override;
+
+  /// Post process after all instructions in this function are processed.
+  void endFunctionImpl(const MachineFunction *MF) override;
+
+public:
+  BTFDebug(AsmPrinter *AP);
+
+  /// Get the special array index type id.
+  uint32_t getArrayIndexTypeId() {
+    assert(ArrayIndexTypeId);
+    return ArrayIndexTypeId;
+  }
+
+  /// Add string to the string table.
+  size_t addString(StringRef S) { return StringTable.addString(S); }
+
+  /// Get the type id for a particular DIType.
+  uint32_t getTypeId(const DIType *Ty) {
+    assert(Ty && "Invalid null Type");
+    assert(DIToIdMap.find(Ty) != DIToIdMap.end() &&
+           "DIType not added in the BDIToIdMap");
+    return DIToIdMap[Ty];
+  }
+
+  void setSymbolSize(const MCSymbol *Symbol, uint64_t Size) override {}
+
+  /// Process beginning of an instruction.
+  void beginInstruction(const MachineInstr *MI) override;
+
+  /// Complete all the types and emit the BTF sections.
+  void endModule() override;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_LIB_CODEGEN_ASMPRINTER_BTFDEBUG_H

lib/CodeGen/AsmPrinter/BTFDebug.cpp

+//===- llvm/lib/CodeGen/AsmPrinter/BTFDebug.cpp ---------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains support for writing BTF debug info.
+//
+//===----------------------------------------------------------------------===//
+
+#include "BTFDebug.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCObjectFileInfo.h"
+#include "llvm/MC/MCSectionELF.h"
+#include "llvm/MC/MCStreamer.h"
+#include <fstream>
+#include <sstream>
+
+using namespace llvm;
+
+static const char *BTFKindStr[] = {
+#define HANDLE_BTF_KIND(ID, NAME) "BTF_KIND_" #NAME,
+#include "llvm/BinaryFormat/BTF.def"
+};
+
+/// Emit a BTF common type.
+void BTFTypeBase::emitType(MCStreamer &OS) {
+  OS.AddComment(std::string(BTFKindStr[Kind]) + "(id = " + std::to_string(Id) +
+                ")");
+  OS.EmitIntValue(BTFType.NameOff, 4);
+  OS.AddComment("0x" + Twine::utohexstr(BTFType.Info));
+  OS.EmitIntValue(BTFType.Info, 4);
+  OS.EmitIntValue(BTFType.Size, 4);
+}
+
+BTFTypeDerived::BTFTypeDerived(const DIDerivedType *DTy, unsigned Tag)
+    : DTy(DTy) {
+  switch (Tag) {
+  case dwarf::DW_TAG_pointer_type:
+    Kind = BTF::BTF_KIND_PTR;
+    break;
+  case dwarf::DW_TAG_const_type:
+    Kind = BTF::BTF_KIND_CONST;
+    break;
+  case dwarf::DW_TAG_volatile_type:
+    Kind = BTF::BTF_KIND_VOLATILE;
+    break;
+  case dwarf::DW_TAG_typedef:
+    Kind = BTF::BTF_KIND_TYPEDEF;
+    break;
+  case dwarf::DW_TAG_restrict_type:
+    Kind = BTF::BTF_KIND_RESTRICT;
+    break;
+  default:
+    llvm_unreachable("Unknown DIDerivedType Tag");
+  }
+  BTFType.Info = Kind << 24;
+}
+
+void BTFTypeDerived::completeType(BTFDebug &BDebug) {
+  BTFType.NameOff = BDebug.addString(DTy->getName());
+
+  // The base type for PTR/CONST/VOLATILE could be void.
+  const DIType *ResolvedType = DTy->getBaseType().resolve();
+  if (!ResolvedType) {
+    assert((Kind == BTF::BTF_KIND_PTR || Kind == BTF::BTF_KIND_CONST ||
+            Kind == BTF::BTF_KIND_VOLATILE) &&
+           "Invalid null basetype");
+    BTFType.Type = 0;
+  } else {
+    BTFType.Type = BDebug.getTypeId(ResolvedType);
+  }
+}
+
+void BTFTypeDerived::emitType(MCStreamer &OS) { BTFTypeBase::emitType(OS); }
+
+/// Represent a struct/union forward declaration.
+BTFTypeFwd::BTFTypeFwd(StringRef Name, bool IsUnion) : Name(Name) {
+  Kind = BTF::BTF_KIND_FWD;
+  BTFType.Info = IsUnion << 31 | Kind << 24;
+  BTFType.Type = 0;
+}
+
+void BTFTypeFwd::completeType(BTFDebug &BDebug) {
+  BTFType.NameOff = BDebug.addString(Name);
+}
+
+void BTFTypeFwd::emitType(MCStreamer &OS) { BTFTypeBase::emitType(OS); }
+
+BTFTypeInt::BTFTypeInt(uint32_t Encoding, uint32_t SizeInBits,
+                       uint32_t OffsetInBits, StringRef TypeName)
+    : Name(TypeName) {
+  // Translate IR int encoding to BTF int encoding.
+  uint8_t BTFEncoding;
+  switch (Encoding) {
+  case dwarf::DW_ATE_boolean:
+    BTFEncoding = BTF::INT_BOOL;
+    break;
+  case dwarf::DW_ATE_signed:
+  case dwarf::DW_ATE_signed_char:
+    BTFEncoding = BTF::INT_SIGNED;
+    break;
+  case dwarf::DW_ATE_unsigned:
+  case dwarf::DW_ATE_unsigned_char:
+    BTFEncoding = 0;
+    break;
+  default:
+    llvm_unreachable("Unknown BTFTypeInt Encoding");
+  }
+
+  Kind = BTF::BTF_KIND_INT;
+  BTFType.Info = Kind << 24;
+  BTFType.Size = roundupToBytes(SizeInBits);
+  IntVal = (BTFEncoding << 24) | OffsetInBits << 16 | SizeInBits;
+}
+
+void BTFTypeInt::completeType(BTFDebug &BDebug) {
+  BTFType.NameOff = BDebug.addString(Name);
+}
+
+void BTFTypeInt::emitType(MCStreamer &OS) {
+  BTFTypeBase::emitType(OS);
+  OS.AddComment("0x" + Twine::utohexstr(IntVal));
+  OS.EmitIntValue(IntVal, 4);
+}
+
+BTFTypeEnum::BTFTypeEnum(const DICompositeType *ETy, uint32_t VLen) : ETy(ETy) {
+  Kind = BTF::BTF_KIND_ENUM;
+  BTFType.Info = Kind << 24 | VLen;
+  BTFType.Size = roundupToBytes(ETy->getSizeInBits());
+}
+
+void BTFTypeEnum::completeType(BTFDebug &BDebug) {
+  BTFType.NameOff = BDebug.addString(ETy->getName());
+
+  DINodeArray Elements = ETy->getElements();
+  for (const auto Element : Elements) {
+    const auto *Enum = cast<DIEnumerator>(Element);
+
+    struct BTF::BTFEnum BTFEnum;
+    BTFEnum.NameOff = BDebug.addString(Enum->getName());
+    // BTF enum value is 32bit, enforce it.
+    BTFEnum.Val = static_cast<uint32_t>(Enum->getValue());
+    EnumValues.push_back(BTFEnum);
+  }
+}
+
+void BTFTypeEnum::emitType(MCStreamer &OS) {
+  BTFTypeBase::emitType(OS);
+  for (const auto &Enum : EnumValues) {
+    OS.EmitIntValue(Enum.NameOff, 4);
+    OS.EmitIntValue(Enum.Val, 4);
+  }
+}
+
+BTFTypeArray::BTFTypeArray(const DICompositeType *ATy) : ATy(ATy) {
+  Kind = BTF::BTF_KIND_ARRAY;
+  BTFType.Info = Kind << 24;
+}
+
+/// Represent a BTF array. BTF does not record array dimensions,
+/// so conceptually a BTF array is a one-dimensional array.
+void BTFTypeArray::completeType(BTFDebug &BDebug) {
+  BTFType.NameOff = BDebug.addString(ATy->getName());
+  BTFType.Size = 0;
+
+  auto *BaseType = ATy->getBaseType().resolve();
+  ArrayInfo.ElemType = BDebug.getTypeId(BaseType);
+
+  // The IR does not really have a type for the index.
+  // A special type for array index should have been
+  // created during initial type traversal. Just
+  // retrieve that type id.
+  ArrayInfo.IndexType = BDebug.getArrayIndexTypeId();
+
+  // Get the number of array elements.
+  // If the array size is 0, set the number of elements as 0.
+  // Otherwise, recursively traverse the base types to
+  // find the element size. The number of elements is
+  // the totoal array size in bits divided by
+  // element size in bits.
+  uint64_t ArraySizeInBits = ATy->getSizeInBits();
+  if (!ArraySizeInBits) {
+    ArrayInfo.Nelems = 0;
+  } else {
+    uint32_t BaseTypeSize = BaseType->getSizeInBits();
+    while (!BaseTypeSize) {
+      const auto *DDTy = cast<DIDerivedType>(BaseType);
+      BaseType = DDTy->getBaseType().resolve();
+      assert(BaseType);
+      BaseTypeSize = BaseType->getSizeInBits();
+    }
+    ArrayInfo.Nelems = ATy->getSizeInBits() / BaseTypeSize;
+  }
+}
+
+void BTFTypeArray::emitType(MCStreamer &OS) {
+  BTFTypeBase::emitType(OS);
+  OS.EmitIntValue(ArrayInfo.ElemType, 4);
+  OS.EmitIntValue(ArrayInfo.IndexType, 4);
+  OS.EmitIntValue(ArrayInfo.Nelems, 4);
+}
+
+/// Represent either a struct or a union.
+BTFTypeStruct::BTFTypeStruct(const DICompositeType *STy, bool IsStruct,
+                             bool HasBitField, uint32_t Vlen)
+    : STy(STy), HasBitField(HasBitField) {
+  Kind = IsStruct ? BTF::BTF_KIND_STRUCT : BTF::BTF_KIND_UNION;
+  BTFType.Size = roundupToBytes(STy->getSizeInBits());
+  BTFType.Info = (HasBitField << 31) | (Kind << 24) | Vlen;
+}
+
+void BTFTypeStruct::completeType(BTFDebug &BDebug) {
+  BTFType.NameOff = BDebug.addString(STy->getName());
+
+  // Add struct/union members.
+  const DINodeArray Elements = STy->getElements();
+  for (const auto *Element : Elements) {
+    struct BTF::BTFMember BTFMember;
+    const auto *DDTy = cast<DIDerivedType>(Element);
+
+    BTFMember.NameOff = BDebug.addString(DDTy->getName());
+    if (HasBitField) {
+      uint8_t BitFieldSize = DDTy->isBitField() ? DDTy->getSizeInBits() : 0;
+      BTFMember.Offset = BitFieldSize << 24 | DDTy->getOffsetInBits();
+    } else {
+      BTFMember.Offset = DDTy->getOffsetInBits();
+    }
+    BTFMember.Type = BDebug.getTypeId(DDTy->getBaseType().resolve());
+    Members.push_back(BTFMember);
+  }
+}
+
+void BTFTypeStruct::emitType(MCStreamer &OS) {
+  BTFTypeBase::emitType(OS);
+  for (const auto &Member : Members) {
+    OS.EmitIntValue(Member.NameOff, 4);
+    OS.EmitIntValue(Member.Type, 4);
+    OS.AddComment("0x" + Twine::utohexstr(Member.Offset));
+    OS.EmitIntValue(Member.Offset, 4);
+  }
+}
+
+/// The Func kind represents both subprogram and pointee of function
+/// pointers. If the FuncName is empty, it represents a pointee of function
+/// pointer. Otherwise, it represents a subprogram. The func arg names
+/// are empty for pointee of function pointer case, and are valid names
+/// for subprogram.
+BTFTypeFuncProto::BTFTypeFuncProto(
+    const DISubroutineType *STy, uint32_t VLen,
+    const std::unordered_map<uint32_t, StringRef> &FuncArgNames)
+    : STy(STy), FuncArgNames(FuncArgNames) {
+  Kind = BTF::BTF_KIND_FUNC_PROTO;
+  BTFType.Info = (Kind << 24) | VLen;
+}
+
+void BTFTypeFuncProto::completeType(BTFDebug &BDebug) {
+  DITypeRefArray Elements = STy->getTypeArray();
+  auto RetType = Elements[0].resolve();
+  BTFType.Type = RetType ? BDebug.getTypeId(RetType) : 0;
+  BTFType.NameOff = 0;
+
+  // For null parameter which is typically the last one
+  // to represent the vararg, encode the NameOff/Type to be 0.
+  for (unsigned I = 1, N = Elements.size(); I < N; ++I) {
+    struct BTF::BTFParam Param;
+    auto Element = Elements[I].resolve();
+    if (Element) {
+      Param.NameOff = BDebug.addString(FuncArgNames[I]);
+      Param.Type = BDebug.getTypeId(Element);
+    } else {
+      Param.NameOff = 0;
+      Param.Type = 0;
+    }
+    Parameters.push_back(Param);
+  }
+}
+
+void BTFTypeFuncProto::emitType(MCStreamer &OS) {
+  BTFTypeBase::emitType(OS);
+  for (const auto &Param : Parameters) {
+    OS.EmitIntValue(Param.NameOff, 4);
+    OS.EmitIntValue(Param.Type, 4);
+  }
+}
+
+BTFTypeFunc::BTFTypeFunc(StringRef FuncName, uint32_t ProtoTypeId)
+    : Name(FuncName) {
+  Kind = BTF::BTF_KIND_FUNC;
+  BTFType.Info = Kind << 24;
+  BTFType.Type = ProtoTypeId;
+}
+
+void BTFTypeFunc::completeType(BTFDebug &BDebug) {
+  BTFType.NameOff = BDebug.addString(Name);
+}
+
+void BTFTypeFunc::emitType(MCStreamer &OS) { BTFTypeBase::emitType(OS); }
+
+uint32_t BTFStringTable::addString(StringRef S) {
+  // Check whether the string already exists.
+  for (auto &OffsetM : OffsetToIdMap) {
+    if (Table[OffsetM.second] == S)
+      return OffsetM.first;
+  }
+  // Not find, add to the string table.
+  uint32_t Offset = Size;
+  OffsetToIdMap[Offset] = Table.size();
+  Table.push_back(S);
+  Size += S.size() + 1;
+  return Offset;
+}
+
+BTFDebug::BTFDebug(AsmPrinter *AP)
+    : DebugHandlerBase(AP), OS(*Asm->OutStreamer), SkipInstruction(false),
+      LineInfoGenerated(false), SecNameOff(0), ArrayIndexTypeId(0) {
+  addString("\0");
+}
+
+void BTFDebug::addType(std::unique_ptr<BTFTypeBase> TypeEntry,
+                       const DIType *Ty) {
+  TypeEntry->setId(TypeEntries.size() + 1);
+  DIToIdMap[Ty] = TypeEntry->getId();
+  TypeEntries.push_back(std::move(TypeEntry));
+}
+
+uint32_t BTFDebug::addType(std::unique_ptr<BTFTypeBase> TypeEntry) {
+  TypeEntry->setId(TypeEntries.size() + 1);
+  uint32_t Id = TypeEntry->getId();
+  TypeEntries.push_back(std::move(TypeEntry));
+  return Id;
+}
+
+void BTFDebug::visitBasicType(const DIBasicType *BTy) {
+  // Only int types are supported in BTF.
+  uint32_t Encoding = BTy->getEncoding();
+  if (Encoding != dwarf::DW_ATE_boolean && Encoding != dwarf::DW_ATE_signed &&
+      Encoding != dwarf::DW_ATE_signed_char &&
+      Encoding != dwarf::DW_ATE_unsigned &&
+      Encoding != dwarf::DW_ATE_unsigned_char)
+    return;
+
+  // Create a BTF type instance for this DIBasicType and put it into
+  // DIToIdMap for cross-type reference check.
+  auto TypeEntry = llvm::make_unique<BTFTypeInt>(
+      Encoding, BTy->getSizeInBits(), BTy->getOffsetInBits(), BTy->getName());
+  addType(std::move(TypeEntry), BTy);
+}
+
+/// Handle subprogram or subroutine types.
+void BTFDebug::visitSubroutineType(
+    const DISubroutineType *STy, bool ForSubprog,
+    const std::unordered_map<uint32_t, StringRef> &FuncArgNames,
+    uint32_t &TypeId) {
+  DITypeRefArray Elements = STy->getTypeArray();
+  uint32_t VLen = Elements.size() - 1;
+  if (VLen > BTF::MAX_VLEN)
+    return;
+
+  // Subprogram has a valid non-zero-length name, and the pointee of
+  // a function pointer has an empty name. The subprogram type will
+  // not be added to DIToIdMap as it should not be referenced by
+  // any other types.
+  auto TypeEntry = llvm::make_unique<BTFTypeFuncProto>(STy, VLen, FuncArgNames);
+  if (ForSubprog)
+    TypeId = addType(std::move(TypeEntry)); // For subprogram
+  else
+    addType(std::move(TypeEntry), STy); // For func ptr
+
+  // Visit return type and func arg types.
+  for (const auto Element : Elements) {
+    visitTypeEntry(Element.resolve());
+  }
+}
+
+/// Handle structure/union types.
+void BTFDebug::visitStructType(const DICompositeType *CTy, bool IsStruct) {
+  const DINodeArray Elements = CTy->getElements();
+  uint32_t VLen = Elements.size();
+  if (VLen > BTF::MAX_VLEN)
+    return;
+
+  // Check whether we have any bitfield members or not
+  bool HasBitField = false;
+  for (const auto *Element : Elements) {
+    auto E = cast<DIDerivedType>(Element);
+    if (E->isBitField()) {
+      HasBitField = true;
+      break;
+    }
+  }
+
+  auto TypeEntry =
+      llvm::make_unique<BTFTypeStruct>(CTy, IsStruct, HasBitField, VLen);
+  addType(std::move(TypeEntry), CTy);
+
+  // Visit all struct members.
+  for (const auto *Element : Elements)
+    visitTypeEntry(cast<DIDerivedType>(Element));
+}
+
+void BTFDebug::visitArrayType(const DICompositeType *CTy) {
+  auto TypeEntry = llvm::make_unique<BTFTypeArray>(CTy);
+  addType(std::move(TypeEntry), CTy);
+
+  // The IR does not have a type for array index while BTF wants one.
+  // So create an array index type if there is none.
+  if (!ArrayIndexTypeId) {
+    auto TypeEntry = llvm::make_unique<BTFTypeInt>(dwarf::DW_ATE_unsigned, 32,
+                                                   0, "__ARRAY_SIZE_TYPE__");
+    ArrayIndexTypeId = addType(std::move(TypeEntry));
+  }
+
+  // Visit array element type.
+  visitTypeEntry(CTy->getBaseType().resolve());
+}
+
+void BTFDebug::visitEnumType(const DICompositeType *CTy) {
+  DINodeArray Elements = CTy->getElements();
+  uint32_t VLen = Elements.size();
+  if (VLen > BTF::MAX_VLEN)
+    return;
+
+  auto TypeEntry = llvm::make_unique<BTFTypeEnum>(CTy, VLen);
+  addType(std::move(TypeEntry), CTy);
+  // No need to visit base type as BTF does not encode it.
+}
+
+/// Handle structure/union forward declarations.
+void BTFDebug::visitFwdDeclType(const DICompositeType *CTy, bool IsUnion) {
+  auto TypeEntry = llvm::make_unique<BTFTypeFwd>(CTy->getName(), IsUnion);
+  addType(std::move(TypeEntry), CTy);
+}
+
+/// Handle structure, union, array and enumeration types.
+void BTFDebug::visitCompositeType(const DICompositeType *CTy) {
+  auto Tag = CTy->getTag();
+  if (Tag == dwarf::DW_TAG_structure_type || Tag == dwarf::DW_TAG_union_type) {
+    // Handle forward declaration differently as it does not have members.
+    if (CTy->isForwardDecl())
+      visitFwdDeclType(CTy, Tag == dwarf::DW_TAG_union_type);
+    else
+      visitStructType(CTy, Tag == dwarf::DW_TAG_structure_type);
+  } else if (Tag == dwarf::DW_TAG_array_type)
+    visitArrayType(CTy);
+  else if (Tag == dwarf::DW_TAG_enumeration_type)
+    visitEnumType(CTy);
+}
+
+/// Handle pointer, typedef, const, volatile, restrict and member types.
+void BTFDebug::visitDerivedType(const DIDerivedType *DTy) {
+  unsigned Tag = DTy->getTag();
+
+  if (Tag == dwarf::DW_TAG_pointer_type || Tag == dwarf::DW_TAG_typedef ||
+      Tag == dwarf::DW_TAG_const_type || Tag == dwarf::DW_TAG_volatile_type ||
+      Tag == dwarf::DW_TAG_restrict_type) {
+    auto TypeEntry = llvm::make_unique<BTFTypeDerived>(DTy, Tag);
+    addType(std::move(TypeEntry), DTy);
+  } else if (Tag != dwarf::DW_TAG_member) {
+    return;
+  }
+
+  // Visit base type of pointer, typedef, const, volatile, restrict or
+  // struct/union member.
+  visitTypeEntry(DTy->getBaseType().resolve());
+}
+
+void BTFDebug::visitTypeEntry(const DIType *Ty) {
+  if (!Ty || DIToIdMap.find(Ty) != DIToIdMap.end())
+    return;
+
+  uint32_t TypeId;
+  if (const auto *BTy = dyn_cast<DIBasicType>(Ty))
+    visitBasicType(BTy);
+  else if (const auto *STy = dyn_cast<DISubroutineType>(Ty))
+    visitSubroutineType(STy, false, std::unordered_map<uint32_t, StringRef>(),
+                        TypeId);
+  else if (const auto *CTy = dyn_cast<DICompositeType>(Ty))
+    visitCompositeType(CTy);
+  else if (const auto *DTy = dyn_cast<DIDerivedType>(Ty))
+    visitDerivedType(DTy);
+  else
+    llvm_unreachable("Unknown DIType");
+}
+
+/// Read file contents from the actual file or from the source
+std::string BTFDebug::populateFileContent(const DISubprogram *SP) {
+  auto File = SP->getFile();
+  std::string FileName;
+
+  if (File->getDirectory().size())
+    FileName = File->getDirectory().str() + "/" + File->getFilename().str();
+  else
+    FileName = File->getFilename();
+
+  // No need to populate the contends if it has been populated!
+  if (FileContent.find(FileName) != FileContent.end())
+    return FileName;
+
+  std::vector<std::string> Content;
+  std::string Line;
+  Content.push_back(Line); // Line 0 for empty string
+
+  auto Source = File->getSource();
+  if (Source) {
+    std::istringstream InputString(Source.getValue());
+    while (std::getline(InputString, Line))
+      Content.push_back(Line);
+  } else {
+    std::ifstream InputFile(FileName);
+    while (std::getline(InputFile, Line))
+      Content.push_back(Line);
+  }
+
+  FileContent[FileName] = Content;
+  return FileName;
+}
+
+void BTFDebug::constructLineInfo(const DISubprogram *SP, MCSymbol *Label,
+                                 uint32_t Line, uint32_t Column) {
+  std::string FileName = populateFileContent(SP);
+  BTFLineInfo LineInfo;
+
+  LineInfo.Label = Label;
+  LineInfo.FileNameOff = addString(FileName);
+  // If file content is not available, let LineOff = 0.
+  if (Line < FileContent[FileName].size())
+    LineInfo.LineOff = addString(FileContent[FileName][Line]);
+  else
+    LineInfo.LineOff = 0;
+  LineInfo.LineNum = Line;
+  LineInfo.ColumnNum = Column;
+  LineInfoTable[SecNameOff].push_back(LineInfo);
+}
+
+void BTFDebug::emitCommonHeader() {
+  OS.AddComment("0x" + Twine::utohexstr(BTF::MAGIC));
+  OS.EmitIntValue(BTF::MAGIC, 2);
+  OS.EmitIntValue(BTF::VERSION, 1);
+  OS.EmitIntValue(0, 1);
+}
+
+void BTFDebug::emitBTFSection() {
+  MCContext &context = OS.getContext();
+  OS.SwitchSection(context.getObjectFileInfo()->getBTFSection());
+
+  // Emit header.
+  emitCommonHeader();
+  OS.EmitIntValue(BTF::HeaderSize, 4);
+
+  uint32_t TypeLen = 0, StrLen;
+  for (const auto &TypeEntry : TypeEntries)
+    TypeLen += TypeEntry->getSize();
+  StrLen = StringTable.getSize();
+
+  OS.EmitIntValue(0, 4);
+  OS.EmitIntValue(TypeLen, 4);
+  OS.EmitIntValue(TypeLen, 4);
+  OS.EmitIntValue(StrLen, 4);
+
+  // Emit type table.
+  for (const auto &TypeEntry : TypeEntries)
+    TypeEntry->emitType(OS);
+
+  // Emit string table.
+  uint32_t StringOffset = 0;
+  for (const auto &S : StringTable.getTable()) {
+    OS.AddComment("string offset=" + std::to_string(StringOffset));
+    OS.EmitBytes(S);
+    OS.EmitBytes(StringRef("\0", 1));
+    StringOffset += S.size() + 1;
+  }
+}
+
+void BTFDebug::emitBTFExtSection() {
+  MCContext &context = OS.getContext();
+  OS.SwitchSection(context.getObjectFileInfo()->getBTFExtSection());
+
+  // Emit header.
+  emitCommonHeader();
+  OS.EmitIntValue(BTF::ExtHeaderSize, 4);
+
+  // Account for FuncInfo/LineInfo record size as well.
+  uint32_t FuncLen = 4, LineLen = 4;
+  for (const auto &FuncSec : FuncInfoTable) {
+    FuncLen += BTF::SecFuncInfoSize;
+    FuncLen += FuncSec.second.size() * BTF::BPFFuncInfoSize;
+  }
+  for (const auto &LineSec : LineInfoTable) {
+    LineLen += BTF::SecLineInfoSize;
+    LineLen += LineSec.second.size() * BTF::BPFLineInfoSize;
+  }
+
+  OS.EmitIntValue(0, 4);
+  OS.EmitIntValue(FuncLen, 4);
+  OS.EmitIntValue(FuncLen, 4);
+  OS.EmitIntValue(LineLen, 4);
+
+  // Emit func_info table.
+  OS.AddComment("FuncInfo");
+  OS.EmitIntValue(BTF::BPFFuncInfoSize, 4);
+  for (const auto &FuncSec : FuncInfoTable) {
+    OS.AddComment("FuncInfo section string offset=" +
+                  std::to_string(FuncSec.first));
+    OS.EmitIntValue(FuncSec.first, 4);
+    OS.EmitIntValue(FuncSec.second.size(), 4);
+    for (const auto &FuncInfo : FuncSec.second) {
+      Asm->EmitLabelReference(FuncInfo.Label, 4);
+      OS.EmitIntValue(FuncInfo.TypeId, 4);
+    }
+  }
+
+  // Emit line_info table.
+  OS.AddComment("LineInfo");
+  OS.EmitIntValue(BTF::BPFLineInfoSize, 4);
+  for (const auto &LineSec : LineInfoTable) {
+    OS.AddComment("LineInfo section string offset=" +
+                  std::to_string(LineSec.first));
+    OS.EmitIntValue(LineSec.first, 4);
+    OS.EmitIntValue(LineSec.second.size(), 4);
+    for (const auto &LineInfo : LineSec.second) {
+      Asm->EmitLabelReference(LineInfo.Label, 4);
+      OS.EmitIntValue(LineInfo.FileNameOff, 4);
+      OS.EmitIntValue(LineInfo.LineOff, 4);
+      OS.AddComment("Line " + std::to_string(LineInfo.LineNum) + " Col " +
+                    std::to_string(LineInfo.ColumnNum));
+      OS.EmitIntValue(LineInfo.LineNum << 10 | LineInfo.ColumnNum, 4);
+    }
+  }
+}
+
+void BTFDebug::beginFunctionImpl(const MachineFunction *MF) {
+  auto *SP = MF->getFunction().getSubprogram();
+  auto *Unit = SP->getUnit();
+
+  if (Unit->getEmissionKind() == DICompileUnit::NoDebug) {
+    SkipInstruction = true;
+    return;
+  }
+  SkipInstruction = false;
+
+  // Collect all types locally referenced in this function.
+  // Use RetainedNodes so we can collect all argument names
+  // even if the argument is not used.
+  std::unordered_map<uint32_t, StringRef> FuncArgNames;
+  for (const DINode *DN : SP->getRetainedNodes()) {
+    if (const auto *DV = dyn_cast<DILocalVariable>(DN)) {
+      visitTypeEntry(DV->getType().resolve());
+
+      // Collect function arguments for subprogram func type.
+      uint32_t Arg = DV->getArg();
+      if (Arg)
+        FuncArgNames[Arg] = DV->getName();
+    }
+  }
+
+  // Construct subprogram func proto type.
+  uint32_t ProtoTypeId;
+  visitSubroutineType(SP->getType(), true, FuncArgNames, ProtoTypeId);
+
+  // Construct subprogram func type
+  auto FuncTypeEntry =
+      llvm::make_unique<BTFTypeFunc>(SP->getName(), ProtoTypeId);
+  uint32_t FuncTypeId = addType(std::move(FuncTypeEntry));
+
+  // Construct funcinfo and the first lineinfo for the function.
+  MCSymbol *FuncLabel = Asm->getFunctionBegin();
+  BTFFuncInfo FuncInfo;
+  FuncInfo.Label = FuncLabel;
+  FuncInfo.TypeId = FuncTypeId;
+  if (FuncLabel->isInSection()) {
+    MCSection &Section = FuncLabel->getSection();
+    const MCSectionELF *SectionELF = dyn_cast<MCSectionELF>(&Section);
+    assert(SectionELF && "Null section for Function Label");
+    SecNameOff = addString(SectionELF->getSectionName());
+  } else {
+    SecNameOff = addString(".text");
+  }
+  FuncInfoTable[SecNameOff].push_back(FuncInfo);
+}
+
+void BTFDebug::endFunctionImpl(const MachineFunction *MF) {
+  SkipInstruction = false;
+  LineInfoGenerated = false;
+  SecNameOff = 0;
+}
+
+void BTFDebug::beginInstruction(const MachineInstr *MI) {
+  DebugHandlerBase::beginInstruction(MI);
+
+  if (SkipInstruction || MI->isMetaInstruction() ||
+      MI->getFlag(MachineInstr::FrameSetup))
+    return;
+
+  if (MI->isInlineAsm()) {
+    // Count the number of register definitions to find the asm string.
+    unsigned NumDefs = 0;
+    for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
+         ++NumDefs)
+      ;
+
+    // Skip this inline asm instruction if the asmstr is empty.
+    const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
+    if (AsmStr[0] == 0)
+      return;
+  }
+
+  // Skip this instruction if no DebugLoc or the DebugLoc
+  // is the same as the previous instruction.
+  const DebugLoc &DL = MI->getDebugLoc();
+  if (!DL || PrevInstLoc == DL) {
+    // This instruction will be skipped, no LineInfo has
+    // been generated, construct one based on function signature.
+    if (LineInfoGenerated == false) {
+      auto *S = MI->getMF()->getFunction().getSubprogram();
+      MCSymbol *FuncLabel = Asm->getFunctionBegin();
+      constructLineInfo(S, FuncLabel, S->getLine(), 0);
+      LineInfoGenerated = true;
+    }
+
+    return;
+  }
+
+  // Create a temporary label to remember the insn for lineinfo.
+  MCSymbol *LineSym = OS.getContext().createTempSymbol();
+  OS.EmitLabel(LineSym);
+
+  // Construct the lineinfo.
+  auto SP = DL.get()->getScope()->getSubprogram();
+  constructLineInfo(SP, LineSym, DL.getLine(), DL.getCol());
+
+  LineInfoGenerated = true;
+  PrevInstLoc = DL;
+}
+
+void BTFDebug::endModule() {
+  // Collect all types referenced by globals.
+  const Module *M = MMI->getModule();
+  for (const DICompileUnit *CUNode : M->debug_compile_units()) {
+    for (const auto *GVE : CUNode->getGlobalVariables()) {
+      DIGlobalVariable *GV = GVE->getVariable();
+      visitTypeEntry(GV->getType().resolve());
+    }
+  }
+
+  // Complete BTF type cross refereences.
+  for (const auto &TypeEntry : TypeEntries)
+    TypeEntry->completeType(*this);
+
+  // Emit BTF sections.
+  emitBTFSection();
+  emitBTFExtSection();
+}

lib/CodeGen/AsmPrinter/BTFDebugStub.cpp

+//===- llvm/lib/CodeGen/AsmPrinter/BTFDebugStub.cpp -------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file is a stub for BTF generation support. The real implementation
+/// is at BTFDebug.cpp which will be included if BPF target is built.
+///
+//===----------------------------------------------------------------------===//
+
+#include "BTFDebug.h"
+#include "llvm/CodeGen/AsmPrinter.h"
+
+using namespace llvm;
+
+BTFDebug::BTFDebug(AsmPrinter *AP)
+    : DebugHandlerBase(AP), OS(*Asm->OutStreamer) {}
+
+void BTFDebug::beginFunctionImpl(const MachineFunction *MF) {}
+
+void BTFDebug::endFunctionImpl(const MachineFunction *MF) {}
+
+void BTFDebug::beginInstruction(const MachineInstr *MI) {
+  DebugHandlerBase::beginInstruction(MI);
+}
+
+void BTFDebug::endModule() {}

lib/CodeGen/AsmPrinter/CMakeLists.txt

+# Based on whether BPF target is built or not,
+# either BTFDebug.cpp or BTFDebugStub.cpp will be included,
+# but not both.
+set(LLVM_OPTIONAL_SOURCES "BTFDebug.cpp" "BTFDebugStub.cpp")
+list(FIND LLVM_TARGETS_TO_BUILD "BPF" idx)
+if( NOT idx LESS 0 )
+  set(BTFDebug_File "BTFDebug.cpp")
+else()
+  set(BTFDebug_File "BTFDebugStub.cpp")
+endif()
+
 add_llvm_library(LLVMAsmPrinter
   AccelTable.cpp
   AddressPool.cpp
   ARMException.cpp
   AsmPrinter.cpp
   AsmPrinterDwarf.cpp
   AsmPrinterInlineAsm.cpp
   DbgEntityHistoryCalculator.cpp
add_llvm_library(LLVMAsmPrinter
   DwarfUnit.cpp
   EHStreamer.cpp
   ErlangGCPrinter.cpp
   OcamlGCPrinter.cpp
   WinCFGuard.cpp
   WinException.cpp
   CodeViewDebug.cpp
   WasmException.cpp
+  ${BTFDebug_File}
 
   DEPENDS
   intrinsics_gen
   )

lib/CodeGen/AsmPrinter/DebugHandlerBase.h

 //===-- llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.h --------*- C++ -*--===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // Common functionality for different debug information format backends.
-// LLVM currently supports DWARF and CodeView.
+// LLVM currently supports DWARF, CodeView and BTF.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGHANDLERBASE_H
 #define LLVM_LIB_CODEGEN_ASMPRINTER_DEBUGHANDLERBASE_H
 
 #include "AsmPrinterHandler.h"
 #include "DbgEntityHistoryCalculator.h"

lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp

 //===-- llvm/lib/CodeGen/AsmPrinter/DebugHandlerBase.cpp -------*- C++ -*--===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // Common functionality for different debug information format backends.
-// LLVM currently supports DWARF and CodeView.
+// LLVM currently supports DWARF, CodeView and BTF.
 //
 //===----------------------------------------------------------------------===//
 
 #include "DebugHandlerBase.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/Twine.h"
 #include "llvm/CodeGen/AsmPrinter.h"
 #include "llvm/CodeGen/MachineFunction.h"

lib/MC/MCObjectFileInfo.cpp

void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T, bool Large) {
 
   FaultMapSection =
       Ctx->getELFSection(".llvm_faultmaps", ELF::SHT_PROGBITS, ELF::SHF_ALLOC);
 
   EHFrameSection =
       Ctx->getELFSection(".eh_frame", EHSectionType, EHSectionFlags);
 
   StackSizesSection = Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, 0);
+
+  BTFSection = Ctx->getELFSection(".BTF", ELF::SHT_PROGBITS, 0);
+  BTFExtSection = Ctx->getELFSection(".BTF.ext", ELF::SHT_PROGBITS, 0);
 }
 
 void MCObjectFileInfo::initCOFFMCObjectFileInfo(const Triple &T) {
   EHFrameSection =
       Ctx->getCOFFSection(".eh_frame", COFF::IMAGE_SCN_CNT_INITIALIZED_DATA |
                                            COFF::IMAGE_SCN_MEM_READ,
                           SectionKind::getData());
 

test/DebugInfo/BTF/array-1d-char.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   char a[10];
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global [10 x i8] zeroinitializer, align 1, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!10, !11, !12}
+!llvm.ident = !{!13}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   56
+; CHECK-NEXT:        .long   56
+; CHECK-NEXT:        .long   26
+; CHECK-NEXT:        .long   0                       # BTF_KIND_ARRAY(id = 1)
+; CHECK-NEXT:        .long   50331648                # 0x3000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   10
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   21                      # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   16777224                # 0x1000008
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "__ARRAY_SIZE_TYPE__"   # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "char"                  # string offset=21
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DICompositeType(tag: DW_TAG_array_type, baseType: !7, size: 80, elements: !8)
+!7 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!8 = !{!9}
+!9 = !DISubrange(count: 10)
+!10 = !{i32 2, !"Dwarf Version", i32 4}
+!11 = !{i32 2, !"Debug Info Version", i32 3}
+!12 = !{i32 1, !"wchar_size", i32 4}
+!13 = !{!"clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)"}

test/DebugInfo/BTF/array-1d-int.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   int a[10];
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global [10 x i32] zeroinitializer, align 4, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!10, !11, !12}
+!llvm.ident = !{!13}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   56
+; CHECK-NEXT:        .long   56
+; CHECK-NEXT:        .long   25
+; CHECK-NEXT:        .long   0                       # BTF_KIND_ARRAY(id = 1)
+; CHECK-NEXT:        .long   50331648                # 0x3000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   10
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   21                      # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "__ARRAY_SIZE_TYPE__"   # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=21
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DICompositeType(tag: DW_TAG_array_type, baseType: !7, size: 320, elements: !8)
+!7 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!8 = !{!9}
+!9 = !DISubrange(count: 10)
+!10 = !{i32 2, !"Dwarf Version", i32 4}
+!11 = !{i32 2, !"Debug Info Version", i32 3}
+!12 = !{i32 1, !"wchar_size", i32 4}
+!13 = !{!"clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)"}

test/DebugInfo/BTF/array-2d-int.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   int a[10][10];
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global [10 x [10 x i32]] zeroinitializer, align 4, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!10, !11, !12}
+!llvm.ident = !{!13}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   56
+; CHECK-NEXT:        .long   56
+; CHECK-NEXT:        .long   25
+; CHECK-NEXT:        .long   0                       # BTF_KIND_ARRAY(id = 1)
+; CHECK-NEXT:        .long   50331648                # 0x3000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   100
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   21                      # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "__ARRAY_SIZE_TYPE__"   # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=21
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DICompositeType(tag: DW_TAG_array_type, baseType: !7, size: 3200, elements: !8)
+!7 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!8 = !{!9, !9}
+!9 = !DISubrange(count: 10)
+!10 = !{i32 2, !"Dwarf Version", i32 4}
+!11 = !{i32 2, !"Debug Info Version", i32 3}
+!12 = !{i32 1, !"wchar_size", i32 4}
+!13 = !{!"clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)"}

test/DebugInfo/BTF/array-size-0.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   struct t {};
+;   struct t a[10];
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+%struct.t = type {}
+
+@a = common dso_local local_unnamed_addr global [10 x %struct.t] zeroinitializer, align 1, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!10, !11, !12}
+!llvm.ident = !{!13}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   52
+; CHECK-NEXT:        .long   52
+; CHECK-NEXT:        .long   23
+; CHECK-NEXT:        .long   0                       # BTF_KIND_ARRAY(id = 1)
+; CHECK-NEXT:        .long   50331648                # 0x3000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   21                      # BTF_KIND_STRUCT(id = 3)
+; CHECK-NEXT:        .long   67108864                # 0x4000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "__ARRAY_SIZE_TYPE__"   # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   116                     # string offset=21
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 2, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DICompositeType(tag: DW_TAG_array_type, baseType: !7, elements: !8)
+!7 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "t", file: !3, line: 1, elements: !4)
+!8 = !{!9}
+!9 = !DISubrange(count: 10)
+!10 = !{i32 2, !"Dwarf Version", i32 4}
+!11 = !{i32 2, !"Debug Info Version", i32 3}
+!12 = !{i32 1, !"wchar_size", i32 4}
+!13 = !{!"clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)"}

test/DebugInfo/BTF/array-typedef.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   typedef unsigned _int;
+;   typedef _int __int;
+;   __int a[10];
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global [10 x i32] zeroinitializer, align 4, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!12, !13, !14}
+!llvm.ident = !{!15}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   80
+; CHECK-NEXT:        .long   80
+; CHECK-NEXT:        .long   45
+; CHECK-NEXT:        .long   0                       # BTF_KIND_ARRAY(id = 1)
+; CHECK-NEXT:        .long   50331648                # 0x3000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   10
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   21                      # BTF_KIND_TYPEDEF(id = 3)
+; CHECK-NEXT:        .long   134217728               # 0x8000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   27                      # BTF_KIND_TYPEDEF(id = 4)
+; CHECK-NEXT:        .long   134217728               # 0x8000000
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   32                      # BTF_KIND_INT(id = 5)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "__ARRAY_SIZE_TYPE__"   # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "__int"                 # string offset=21
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "_int"                  # string offset=27
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "unsigned int"          # string offset=32
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 3, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DICompositeType(tag: DW_TAG_array_type, baseType: !7, size: 320, elements: !10)
+!7 = !DIDerivedType(tag: DW_TAG_typedef, name: "__int", file: !3, line: 2, baseType: !8)
+!8 = !DIDerivedType(tag: DW_TAG_typedef, name: "_int", file: !3, line: 1, baseType: !9)
+!9 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!10 = !{!11}
+!11 = !DISubrange(count: 10)
+!12 = !{i32 2, !"Dwarf Version", i32 4}
+!13 = !{i32 2, !"Debug Info Version", i32 3}
+!14 = !{i32 1, !"wchar_size", i32 4}
+!15 = !{!"clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)"}

test/DebugInfo/BTF/binary-format.ll

+; RUN: llc -march=bpfel -filetype=obj -o - %s | llvm-readelf -x ".BTF" -x ".BTF.ext" | FileCheck -check-prefixes=CHECK,CHECK-EL %s
+; RUN: llc -march=bpfeb -filetype=obj -o - %s | llvm-readelf -x ".BTF" -x ".BTF.ext" | FileCheck -check-prefixes=CHECK,CHECK-EB %s
+
+; Source code:
+;   int f(int a) { return a; }
+; Compilation flag:
+;   clang -target bpf -O2 -g -gdwarf-5 -gembed-source -S -emit-llvm t.c
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @f(i32 returned %a) local_unnamed_addr #0 !dbg !7 {
+entry:
+  call void @llvm.dbg.value(metadata i32 %a, metadata !12, metadata !DIExpression()), !dbg !13
+  ret i32 %a, !dbg !14
+}
+
+; CHECK:    '.BTF'
+; CHECK-EL: 0x00000000 9feb0100 18000000 00000000 30000000
+; CHECK-EL: 0x00000010 30000000 33000000 2b000000 00000001
+; CHECK-EL: 0x00000020 04000000 20000001 00000000 0100000d
+; CHECK-EL: 0x00000030 01000000 2f000000 01000000 31000000
+; CHECK-EL: 0x00000040 0000000c 02000000 002e7465 7874002f
+; CHECK-EB: 0x00000000 eb9f0100 00000018 00000000 00000030
+; CHECK-EB: 0x00000010 00000030 00000033 0000002b 01000000
+; CHECK-EB: 0x00000020 00000004 01000020 00000000 0d000001
+; CHECK-EB: 0x00000030 00000001 0000002f 00000001 00000031
+; CHECK-EB: 0x00000040 0c000000 00000002 002e7465 7874002f
+; CHECK:    0x00000050 746d702f 742e6300 696e7420 6628696e
+; CHECK:    0x00000060 74206129 207b2072 65747572 6e20613b
+; CHECK:    0x00000070 207d0069 6e740061 006600
+; CHECK:    '.BTF.ext'
+; CHECK-EL: 0x00000000 9feb0100 18000000 00000000 14000000
+; CHECK-EL: 0x00000010 14000000 2c000000 08000000 01000000
+; CHECK-EL: 0x00000020 01000000 00000000 03000000 10000000
+; CHECK-EL: 0x00000030 01000000 02000000 00000000 07000000
+; CHECK-EL: 0x00000040 10000000 00040000 08000000 07000000
+; CHECK-EL: 0x00000050 10000000 10040000
+; CHECK-EB: 0x00000000 eb9f0100 00000018 00000000 00000014
+; CHECK-EB: 0x00000010 00000014 0000002c 00000008 00000001
+; CHECK-EB: 0x00000020 00000001 00000000 00000003 00000010
+; CHECK-EB: 0x00000030 00000001 00000002 00000000 00000007
+; CHECK-EB: 0x00000040 00000010 00000400 00000008 00000007
+; CHECK-EB: 0x00000050 00000010 00000410
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #1
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone speculatable }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "t.c", directory: "/tmp", checksumkind: CSK_MD5, checksum: "1924f0d78deb326ceb76cd8e9f450775", source: "int f(int a) { return a; }\0A")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 5}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}
+!7 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, isOptimized: true, unit: !0, retainedNodes: !11)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10, !10}
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !{!12}
+!12 = !DILocalVariable(name: "a", arg: 1, scope: !7, file: !1, line: 1, type: !10)
+!13 = !DILocation(line: 1, column: 11, scope: !7)
+!14 = !DILocation(line: 1, column: 16, scope: !7)

test/DebugInfo/BTF/char.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   char a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global i8 0, align 1, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   6
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   16777224                # 0x1000008
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "char"                  # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/enum-basic.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   enum { A = -1, B = 2 } a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global i32 0, align 4, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!11, !12, !13}
+!llvm.ident = !{!14}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   0                       # BTF_KIND_ENUM(id = 1)
+; CHECK-NEXT:        .long   100663298               # 0x6000002
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   -1
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .byte   65                      # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   66                      # string offset=3
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !5, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !10, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{!5}
+!5 = !DICompositeType(tag: DW_TAG_enumeration_type, file: !3, line: 1, baseType: !6, size: 32, elements: !7)
+!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!7 = !{!8, !9}
+!8 = !DIEnumerator(name: "A", value: -1)
+!9 = !DIEnumerator(name: "B", value: 2)
+!10 = !{!0}
+!11 = !{i32 2, !"Dwarf Version", i32 4}
+!12 = !{i32 2, !"Debug Info Version", i32 3}
+!13 = !{i32 1, !"wchar_size", i32 4}
+!14 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/func-func-ptr.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   void (*a1)(int p1);
+;   struct t1 { void (*a1)(int p1); } b1;
+;   void f1(int p2) { }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+%struct.t1 = type { void (i32)* }
+
+@a1 = common dso_local local_unnamed_addr global void (i32)* null, align 8, !dbg !0
+@b1 = common dso_local local_unnamed_addr global %struct.t1 zeroinitializer, align 8, !dbg !6
+
+; Function Attrs: nounwind readnone
+define dso_local void @f1(i32 %p2) local_unnamed_addr #0 !dbg !19 {
+entry:
+  call void @llvm.dbg.value(metadata i32 %p2, metadata !21, metadata !DIExpression()), !dbg !22
+  ret void, !dbg !23
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   104
+; CHECK-NEXT:        .long   104
+; CHECK-NEXT:        .long   32
+; CHECK-NEXT:        .long   16                      # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 2)
+; CHECK-NEXT:        .long   218103809               # 0xd000001
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   23                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 4)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 5)
+; CHECK-NEXT:        .long   218103809               # 0xd000001
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   26                      # BTF_KIND_STRUCT(id = 6)
+; CHECK-NEXT:        .long   67108865                # 0x4000001
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   29
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=7
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=16
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "p2"                    # string offset=20
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "f1"                    # string offset=23
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "t1"                    # string offset=26
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "a1"                    # string offset=29
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   1                       # FuncInfo section string offset=1
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Lfunc_begin0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   16                      # LineInfo
+; CHECK-NEXT:        .long   1                       # LineInfo section string offset=1
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   3091                    # Line 3 Col 19
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #1
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone speculatable }
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!15, !16, !17}
+!llvm.ident = !{!18}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a1", scope: !2, file: !3, line: 1, type: !11, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/tmp")
+!4 = !{}
+!5 = !{!0, !6}
+!6 = !DIGlobalVariableExpression(var: !7, expr: !DIExpression())
+!7 = distinct !DIGlobalVariable(name: "b1", scope: !2, file: !3, line: 2, type: !8, isLocal: false, isDefinition: true)
+!8 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "t1", file: !3, line: 2, size: 64, elements: !9)
+!9 = !{!10}
+!10 = !DIDerivedType(tag: DW_TAG_member, name: "a1", scope: !8, file: !3, line: 2, baseType: !11, size: 64)
+!11 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !12, size: 64)
+!12 = !DISubroutineType(types: !13)
+!13 = !{null, !14}
+!14 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!15 = !{i32 2, !"Dwarf Version", i32 4}
+!16 = !{i32 2, !"Debug Info Version", i32 3}
+!17 = !{i32 1, !"wchar_size", i32 4}
+!18 = !{!"clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)"}
+!19 = distinct !DISubprogram(name: "f1", scope: !3, file: !3, line: 3, type: !12, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: true, unit: !2, retainedNodes: !20)
+!20 = !{!21}
+!21 = !DILocalVariable(name: "p2", arg: 1, scope: !19, file: !3, line: 3, type: !14)
+!22 = !DILocation(line: 3, column: 13, scope: !19)
+!23 = !DILocation(line: 3, column: 19, scope: !19)

test/DebugInfo/BTF/func-non-void.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   int f1(int a1) { return a1; }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @f1(i32 returned) local_unnamed_addr #0 !dbg !7 {
+  call void @llvm.dbg.value(metadata i32 %0, metadata !12, metadata !DIExpression()), !dbg !13
+  ret i32 %0, !dbg !14
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   26
+; CHECK-NEXT:        .long   16                      # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 2)
+; CHECK-NEXT:        .long   218103809               # 0xd000001
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   23                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=7
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=16
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "a1"                    # string offset=20
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "f1"                    # string offset=23
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   44
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   1                       # FuncInfo section string offset=1
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Lfunc_begin0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   16                      # LineInfo
+; CHECK-NEXT:        .long   1                       # LineInfo section string offset=1
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Lfunc_begin0
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   1024                    # Line 1 Col 0
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   1042                    # Line 1 Col 18
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #1
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone speculatable }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.0 (trunk 345562) (llvm/trunk 345560)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "t.c", directory: "/tmp")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 8.0.0 (trunk 345562) (llvm/trunk 345560)"}
+!7 = distinct !DISubprogram(name: "f1", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !11)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10, !10}
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !{!12}
+!12 = !DILocalVariable(name: "a1", arg: 1, scope: !7, file: !1, line: 1, type: !10)
+!13 = !DILocation(line: 1, column: 12, scope: !7)
+!14 = !DILocation(line: 1, column: 18, scope: !7)

test/DebugInfo/BTF/func-source.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   void f(void) { }
+; Compilation flag:
+;   clang -target bpf -O2 -g -gdwarf-5 -gembed-source -S -emit-llvm t.c
+;
+; This test embeds the source code in the IR, so the line info should have
+; correct reference to the lines in the string table.
+
+; Function Attrs: norecurse nounwind readnone
+define dso_local void @f() local_unnamed_addr #0 !dbg !7 {
+entry:
+  ret void, !dbg !10
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   35
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
+; CHECK-NEXT:        .long   218103808               # 0xd000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   33                      # BTF_KIND_FUNC(id = 2)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=7
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "void f(void) { }"      # string offset=16
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   102                     # string offset=33
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   1                       # FuncInfo section string offset=1
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Lfunc_begin0
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   16                      # LineInfo
+; CHECK-NEXT:        .long   1                       # LineInfo section string offset=1
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   1040                    # Line 1 Col 16
+
+attributes #0 = { norecurse nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "t.c", directory: "/tmp", checksumkind: CSK_MD5, checksum: "978599fafe3a080b456e3d95a3710359", source: "void f(void) { }\0A")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 5}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}
+!7 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, isOptimized: true, unit: !0, retainedNodes: !2)
+!8 = !DISubroutineType(types: !9)
+!9 = !{null}
+!10 = !DILocation(line: 1, column: 16, scope: !7)

test/DebugInfo/BTF/func-typedef.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   typedef int _int;
+;   typedef _int __int;
+;   __int f(__int a) { return a; }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @f(i32 returned %a) local_unnamed_addr #0 !dbg !7 {
+entry:
+  call void @llvm.dbg.value(metadata i32 %a, metadata !14, metadata !DIExpression()), !dbg !15
+  ret i32 %a, !dbg !16
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   72
+; CHECK-NEXT:        .long   72
+; CHECK-NEXT:        .long   35
+; CHECK-NEXT:        .long   16                      # BTF_KIND_TYPEDEF(id = 1)
+; CHECK-NEXT:        .long   134217728               # 0x8000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   22                      # BTF_KIND_TYPEDEF(id = 2)
+; CHECK-NEXT:        .long   134217728               # 0x8000000
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   27                      # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 4)
+; CHECK-NEXT:        .long   218103809               # 0xd000001
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   31
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   33                      # BTF_KIND_FUNC(id = 5)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=7
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "__int"                 # string offset=16
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "_int"                  # string offset=22
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=27
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   97                      # string offset=31
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   102                     # string offset=33
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   44
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   1                       # FuncInfo section string offset=1
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Lfunc_begin0
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   16                      # LineInfo
+; CHECK-NEXT:        .long   1                       # LineInfo section string offset=1
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   .Lfunc_begin0
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   3072                    # Line 3 Col 0
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   3092                    # Line 3 Col 20
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #1
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone speculatable }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "t.c", directory: "/tmp")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}
+!7 = distinct !DISubprogram(name: "f", scope: !1, file: !1, line: 3, type: !8, isLocal: false, isDefinition: true, scopeLine: 3, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !13)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10, !10}
+!10 = !DIDerivedType(tag: DW_TAG_typedef, name: "__int", file: !1, line: 2, baseType: !11)
+!11 = !DIDerivedType(tag: DW_TAG_typedef, name: "_int", file: !1, line: 1, baseType: !12)
+!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!13 = !{!14}
+!14 = !DILocalVariable(name: "a", arg: 1, scope: !7, file: !1, line: 3, type: !10)
+!15 = !DILocation(line: 3, column: 15, scope: !7)
+!16 = !DILocation(line: 3, column: 20, scope: !7)

test/DebugInfo/BTF/func-unused-arg.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   int f1(int a1) { return 0; }
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+; Function Attrs: nounwind readnone
+define dso_local i32 @f1(i32) local_unnamed_addr #0 !dbg !7 {
+  call void @llvm.dbg.value(metadata i32 %0, metadata !12, metadata !DIExpression()), !dbg !13
+  ret i32 0, !dbg !14
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   26
+; CHECK-NEXT:        .long   16                      # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 2)
+; CHECK-NEXT:        .long   218103809               # 0xd000001
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   23                      # BTF_KIND_FUNC(id = 3)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=7
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=16
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "a1"                    # string offset=20
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "f1"                    # string offset=23
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   1                       # FuncInfo section string offset=1
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Lfunc_begin0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   16                      # LineInfo
+; CHECK-NEXT:        .long   1                       # LineInfo section string offset=1
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   1042                    # Line 1 Col 18
+
+; Function Attrs: nounwind readnone speculatable
+declare void @llvm.dbg.value(metadata, metadata, metadata) #1
+
+attributes #0 = { nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { nounwind readnone speculatable }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.0 (trunk 345562) (llvm/trunk 345560)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "t.c", directory: "/tmp")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 8.0.0 (trunk 345562) (llvm/trunk 345560)"}
+!7 = distinct !DISubprogram(name: "f1", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !11)
+!8 = !DISubroutineType(types: !9)
+!9 = !{!10, !10}
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !{!12}
+!12 = !DILocalVariable(name: "a1", arg: 1, scope: !7, file: !1, line: 1, type: !10)
+!13 = !DILocation(line: 1, column: 12, scope: !7)
+!14 = !DILocation(line: 1, column: 18, scope: !7)

test/DebugInfo/BTF/func-void.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   void f1(void) {}
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+; Function Attrs: norecurse nounwind readnone
+define dso_local void @f1() local_unnamed_addr #0 !dbg !7 {
+  ret void, !dbg !10
+}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   19
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 1)
+; CHECK-NEXT:        .long   218103808               # 0xd000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   16                      # BTF_KIND_FUNC(id = 2)
+; CHECK-NEXT:        .long   201326592               # 0xc000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  ".text"                 # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "/tmp/t.c"              # string offset=7
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "f1"                    # string offset=16
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   20
+; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   1                       # FuncInfo section string offset=1
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Lfunc_begin0
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   16                      # LineInfo
+; CHECK-NEXT:        .long   1                       # LineInfo section string offset=1
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   .Ltmp{{[0-9]+}}
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   1040                    # Line 1 Col 16
+
+attributes #0 = { norecurse nounwind readnone "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "min-legal-vector-width"="0" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-jump-tables"="false" "no-nans-fp-math"="false" "no-signed-zeros-fp-math"="false" "no-trapping-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5}
+!llvm.ident = !{!6}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 8.0.0 (trunk 345562) (llvm/trunk 345560)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, nameTableKind: None)
+!1 = !DIFile(filename: "t.c", directory: "/tmp")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{!"clang version 8.0.0 (trunk 345562) (llvm/trunk 345560)"}
+!7 = distinct !DISubprogram(name: "f1", scope: !1, file: !1, line: 1, type: !8, isLocal: false, isDefinition: true, scopeLine: 1, flags: DIFlagPrototyped, isOptimized: true, unit: !0, retainedNodes: !2)
+!8 = !DISubroutineType(types: !9)
+!9 = !{null}
+!10 = !DILocation(line: 1, column: 16, scope: !7)

test/DebugInfo/BTF/fwd-no-define.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   struct t1;
+;   struct t2 {struct t1 *p;} a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+%struct.t2 = type { %struct.t1* }
+%struct.t1 = type opaque
+
+@a = common dso_local local_unnamed_addr global %struct.t2 zeroinitializer, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!11, !12, !13}
+!llvm.ident = !{!14}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   48
+; CHECK-NEXT:        .long   9
+; CHECK-NEXT:        .long   1                       # BTF_KIND_STRUCT(id = 1)
+; CHECK-NEXT:        .long   67108865                # 0x4000001
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 2)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   6                       # BTF_KIND_FWD(id = 3)
+; CHECK-NEXT:        .long   117440512               # 0x7000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "t2"                    # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   112                     # string offset=4
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "t1"                    # string offset=6
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 2, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "t2", file: !3, line: 2, size: 64, elements: !7)
+!7 = !{!8}
+!8 = !DIDerivedType(tag: DW_TAG_member, name: "p", scope: !6, file: !3, line: 2, baseType: !9, size: 64)
+!9 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !10, size: 64)
+!10 = !DICompositeType(tag: DW_TAG_structure_type, name: "t1", file: !3, line: 1, flags: DIFlagFwdDecl)
+!11 = !{i32 2, !"Dwarf Version", i32 4}
+!12 = !{i32 2, !"Debug Info Version", i32 3}
+!13 = !{i32 1, !"wchar_size", i32 4}
+!14 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/fwd-with-define.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   struct t1;
+;   struct t1 {struct t1 *p;} a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+%struct.t1 = type { %struct.t1* }
+
+@a = common dso_local local_unnamed_addr global %struct.t1 zeroinitializer, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!10, !11, !12}
+!llvm.ident = !{!13}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   36
+; CHECK-NEXT:        .long   36
+; CHECK-NEXT:        .long   6
+; CHECK-NEXT:        .long   1                       # BTF_KIND_STRUCT(id = 1)
+; CHECK-NEXT:        .long   67108865                # 0x4000001
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 2)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "t1"                    # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   112                     # string offset=4
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 2, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "t1", file: !3, line: 2, size: 64, elements: !7)
+!7 = !{!8}
+!8 = !DIDerivedType(tag: DW_TAG_member, name: "p", scope: !6, file: !3, line: 2, baseType: !9, size: 64)
+!9 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !6, size: 64)
+!10 = !{i32 2, !"Dwarf Version", i32 4}
+!11 = !{i32 2, !"Debug Info Version", i32 3}
+!12 = !{i32 1, !"wchar_size", i32 4}
+!13 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/int.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   int a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global i32 0, align 4, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/lit.local.cfg

+if not 'BPF' in config.root.targets:
+    config.unsupported = True

test/DebugInfo/BTF/longlong.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   long long a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global i64 0, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   15
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   16777280                # 0x1000040
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "long long int"         # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIBasicType(name: "long long int", size: 64, encoding: DW_ATE_signed)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/ptr-const-void.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   const void *a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@p = common dso_local local_unnamed_addr global i8* null, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!8, !9, !10}
+!llvm.ident = !{!11}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0                       # BTF_KIND_CONST(id = 2)
+; CHECK-NEXT:        .long   167772160               # 0xa000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "p", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = !DIDerivedType(tag: DW_TAG_const_type, baseType: null)
+!8 = !{i32 2, !"Dwarf Version", i32 4}
+!9 = !{i32 2, !"Debug Info Version", i32 3}
+!10 = !{i32 1, !"wchar_size", i32 4}
+!11 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/ptr-func-1.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   void (*a)(void);
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global void ()* null, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!9, !10, !11}
+!llvm.ident = !{!12}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 2)
+; CHECK-NEXT:        .long   218103808               # 0xd000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = !DISubroutineType(types: !8)
+!8 = !{null}
+!9 = !{i32 2, !"Dwarf Version", i32 4}
+!10 = !{i32 2, !"Debug Info Version", i32 3}
+!11 = !{i32 1, !"wchar_size", i32 4}
+!12 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/ptr-func-2.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   int (*a)(int a, char b);
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global i32 (i32, i8)* null, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!11, !12, !13}
+!llvm.ident = !{!14}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   72
+; CHECK-NEXT:        .long   72
+; CHECK-NEXT:        .long   10
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 2)
+; CHECK-NEXT:        .long   218103810               # 0xd000002
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .long   5                       # BTF_KIND_INT(id = 4)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   16777224                # 0x1000008
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "char"                  # string offset=5
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = !DISubroutineType(types: !8)
+!8 = !{!9, !9, !10}
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!11 = !{i32 2, !"Dwarf Version", i32 4}
+!12 = !{i32 2, !"Debug Info Version", i32 3}
+!13 = !{i32 1, !"wchar_size", i32 4}
+!14 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/ptr-func-3.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   typedef int __int;
+;   __int (*a)(__int a, __int b);
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global i32 (i32, i32)* null, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!11, !12, !13}
+!llvm.ident = !{!14}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   68
+; CHECK-NEXT:        .long   68
+; CHECK-NEXT:        .long   11
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0                       # BTF_KIND_FUNC_PROTO(id = 2)
+; CHECK-NEXT:        .long   218103810               # 0xd000002
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   1                       # BTF_KIND_TYPEDEF(id = 3)
+; CHECK-NEXT:        .long   134217728               # 0x8000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   7                       # BTF_KIND_INT(id = 4)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "__int"                 # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=7
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 2, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = !DISubroutineType(types: !8)
+!8 = !{!9, !9, !9}
+!9 = !DIDerivedType(tag: DW_TAG_typedef, name: "__int", file: !3, line: 1, baseType: !10)
+!10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!11 = !{i32 2, !"Dwarf Version", i32 4}
+!12 = !{i32 2, !"Debug Info Version", i32 3}
+!13 = !{i32 1, !"wchar_size", i32 4}
+!14 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/ptr-int.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   int *a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global i32* null, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!8, !9, !10}
+!llvm.ident = !{!11}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   28
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!8 = !{i32 2, !"Dwarf Version", i32 4}
+!9 = !{i32 2, !"Debug Info Version", i32 3}
+!10 = !{i32 1, !"wchar_size", i32 4}
+!11 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/ptr-void.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   void *a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global i8* null, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   12
+; CHECK-NEXT:        .long   12
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: null, size: 64)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)"}

test/DebugInfo/BTF/ptr-volatile-const-void.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   volatile const void *p;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@p = common dso_local local_unnamed_addr global i8* null, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!9, !10, !11}
+!llvm.ident = !{!12}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   36
+; CHECK-NEXT:        .long   36
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0                       # BTF_KIND_CONST(id = 2)
+; CHECK-NEXT:        .long   167772160               # 0xa000000
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0                       # BTF_KIND_VOLATILE(id = 3)
+; CHECK-NEXT:        .long   150994944               # 0x9000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "p", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = !DIDerivedType(tag: DW_TAG_const_type, baseType: !8)
+!8 = !DIDerivedType(tag: DW_TAG_volatile_type, baseType: null)
+!9 = !{i32 2, !"Dwarf Version", i32 4}
+!10 = !{i32 2, !"Debug Info Version", i32 3}
+!11 = !{i32 1, !"wchar_size", i32 4}
+!12 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/ptr-volatile-void.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   volatile void *a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@p = common dso_local local_unnamed_addr global i8* null, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!8, !9, !10}
+!llvm.ident = !{!11}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 1)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0                       # BTF_KIND_VOLATILE(id = 2)
+; CHECK-NEXT:        .long   150994944               # 0x9000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "p", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !7, size: 64)
+!7 = !DIDerivedType(tag: DW_TAG_volatile_type, baseType: null)
+!8 = !{i32 2, !"Dwarf Version", i32 4}
+!9 = !{i32 2, !"Debug Info Version", i32 3}
+!10 = !{i32 1, !"wchar_size", i32 4}
+!11 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/restrict-ptr.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   int * restrict p;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@p = common dso_local local_unnamed_addr global i32* null, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!9, !10, !11}
+!llvm.ident = !{!12}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   40
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   0                       # BTF_KIND_RESTRICT(id = 1)
+; CHECK-NEXT:        .long   184549376               # 0xb000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0                       # BTF_KIND_PTR(id = 2)
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "p", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIDerivedType(tag: DW_TAG_restrict_type, baseType: !7)
+!7 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !8, size: 64)
+!8 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!9 = !{i32 2, !"Dwarf Version", i32 4}
+!10 = !{i32 2, !"Debug Info Version", i32 3}
+!11 = !{i32 1, !"wchar_size", i32 4}
+!12 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/short.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   short a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+
+@a = common dso_local local_unnamed_addr global i16 0, align 2, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   16777232                # 0x1000010
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "short"                 # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIBasicType(name: "short", size: 16, encoding: DW_ATE_signed)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/struct-anon.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   struct { struct {int m;}; } a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+%struct.anon = type { %struct.anon.0 }
+%struct.anon.0 = type { i32 }
+
+@a = common dso_local local_unnamed_addr global %struct.anon zeroinitializer, align 4, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!13, !14, !15}
+!llvm.ident = !{!16}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   64
+; CHECK-NEXT:        .long   64
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   0                       # BTF_KIND_STRUCT(id = 1)
+; CHECK-NEXT:        .long   67108865                # 0x4000001
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   0                       # BTF_KIND_STRUCT(id = 2)
+; CHECK-NEXT:        .long   67108865                # 0x4000001
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   3                       # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .byte   109                     # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=3
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, file: !3, line: 1, size: 32, elements: !7)
+!7 = !{!8}
+!8 = !DIDerivedType(tag: DW_TAG_member, scope: !6, file: !3, line: 1, baseType: !9, size: 32)
+!9 = distinct !DICompositeType(tag: DW_TAG_structure_type, scope: !6, file: !3, line: 1, size: 32, elements: !10)
+!10 = !{!11}
+!11 = !DIDerivedType(tag: DW_TAG_member, name: "m", scope: !9, file: !3, line: 1, baseType: !12, size: 32)
+!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!13 = !{i32 2, !"Dwarf Version", i32 4}
+!14 = !{i32 2, !"Debug Info Version", i32 3}
+!15 = !{i32 1, !"wchar_size", i32 4}
+!16 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/struct-basic.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   struct t1 {char m1; int n1;} a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+%struct.t1 = type { i8, i32 }
+
+@a = common dso_local local_unnamed_addr global %struct.t1 zeroinitializer, align 4, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!12, !13, !14}
+!llvm.ident = !{!15}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   68
+; CHECK-NEXT:        .long   68
+; CHECK-NEXT:        .long   19
+; CHECK-NEXT:        .long   1                       # BTF_KIND_STRUCT(id = 1)
+; CHECK-NEXT:        .long   67108866                # 0x4000002
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   7
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   32
+; CHECK-NEXT:        .long   10                      # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   16777224                # 0x1000008
+; CHECK-NEXT:        .long   15                      # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "t1"                    # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "m1"                    # string offset=4
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "n1"                    # string offset=7
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "char"                  # string offset=10
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=15
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "t1", file: !3, line: 1, size: 64, elements: !7)
+!7 = !{!8, !10}
+!8 = !DIDerivedType(tag: DW_TAG_member, name: "m1", scope: !6, file: !3, line: 1, baseType: !9, size: 8)
+!9 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!10 = !DIDerivedType(tag: DW_TAG_member, name: "n1", scope: !6, file: !3, line: 1, baseType: !11, size: 32, offset: 32)
+!11 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!12 = !{i32 2, !"Dwarf Version", i32 4}
+!13 = !{i32 2, !"Debug Info Version", i32 3}
+!14 = !{i32 1, !"wchar_size", i32 4}
+!15 = !{!"clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)"}

test/DebugInfo/BTF/struct-bitfield-typedef.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   typedef int _int;
+;   typedef _int __int;
+;   struct {char m:2; __int n:3; char p;} a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+%struct.anon = type { i8, i8, [2 x i8] }
+
+@a = common dso_local local_unnamed_addr global %struct.anon zeroinitializer, align 4, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!15, !16, !17}
+!llvm.ident = !{!18}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   104
+; CHECK-NEXT:        .long   104
+; CHECK-NEXT:        .long   27
+; CHECK-NEXT:        .long   0                       # BTF_KIND_STRUCT(id = 1)
+; CHECK-NEXT:        .long   2214592515              # 0x84000003
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   50331650                # 0x3000002
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   8                       # 0x8
+; CHECK-NEXT:        .long   7                       # BTF_KIND_INT(id = 2)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   16777224                # 0x1000008
+; CHECK-NEXT:        .long   12                      # BTF_KIND_TYPEDEF(id = 3)
+; CHECK-NEXT:        .long   134217728               # 0x8000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   18                      # BTF_KIND_TYPEDEF(id = 4)
+; CHECK-NEXT:        .long   134217728               # 0x8000000
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   23                      # BTF_KIND_INT(id = 5)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .byte   109                     # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   110                     # string offset=3
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   112                     # string offset=5
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "char"                  # string offset=7
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "__int"                 # string offset=12
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "_int"                  # string offset=18
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=23
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 3, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, file: !3, line: 3, size: 32, elements: !7)
+!7 = !{!8, !10, !14}
+!8 = !DIDerivedType(tag: DW_TAG_member, name: "m", scope: !6, file: !3, line: 3, baseType: !9, size: 2, flags: DIFlagBitField, extraData: i64 0)
+!9 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!10 = !DIDerivedType(tag: DW_TAG_member, name: "n", scope: !6, file: !3, line: 3, baseType: !11, size: 3, offset: 2, flags: DIFlagBitField, extraData: i64 0)
+!11 = !DIDerivedType(tag: DW_TAG_typedef, name: "__int", file: !3, line: 2, baseType: !12)
+!12 = !DIDerivedType(tag: DW_TAG_typedef, name: "_int", file: !3, line: 1, baseType: !13)
+!13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!14 = !DIDerivedType(tag: DW_TAG_member, name: "p", scope: !6, file: !3, line: 3, baseType: !9, size: 8, offset: 8)
+!15 = !{i32 2, !"Dwarf Version", i32 4}
+!16 = !{i32 2, !"Debug Info Version", i32 3}
+!17 = !{i32 1, !"wchar_size", i32 4}
+!18 = !{!"clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)"}

test/DebugInfo/BTF/struct-enum.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   enum t1 { A , B };
+;   struct t2 { enum t1 m:2; enum t1 n; } a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+%struct.t2 = type { i8, i32 }
+
+@a = common dso_local local_unnamed_addr global %struct.t2 zeroinitializer, align 4, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!15, !16, !17}
+!llvm.ident = !{!18}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   64
+; CHECK-NEXT:        .long   64
+; CHECK-NEXT:        .long   15
+; CHECK-NEXT:        .long   1                       # BTF_KIND_STRUCT(id = 1)
+; CHECK-NEXT:        .long   2214592514              # 0x84000002
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   33554432                # 0x2000000
+; CHECK-NEXT:        .long   6
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   8                       # BTF_KIND_ENUM(id = 2)
+; CHECK-NEXT:        .long   100663298               # 0x6000002
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   11
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   13
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "t2"                    # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   109                     # string offset=4
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   110                     # string offset=6
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "t1"                    # string offset=8
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   65                      # string offset=11
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   66                      # string offset=13
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 2, type: !11, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !10, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{!5}
+!5 = !DICompositeType(tag: DW_TAG_enumeration_type, name: "t1", file: !3, line: 1, baseType: !6, size: 32, elements: !7)
+!6 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!7 = !{!8, !9}
+!8 = !DIEnumerator(name: "A", value: 0, isUnsigned: true)
+!9 = !DIEnumerator(name: "B", value: 1, isUnsigned: true)
+!10 = !{!0}
+!11 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "t2", file: !3, line: 2, size: 64, elements: !12)
+!12 = !{!13, !14}
+!13 = !DIDerivedType(tag: DW_TAG_member, name: "m", scope: !11, file: !3, line: 2, baseType: !5, size: 2, flags: DIFlagBitField, extraData: i64 0)
+!14 = !DIDerivedType(tag: DW_TAG_member, name: "n", scope: !11, file: !3, line: 2, baseType: !5, size: 32, offset: 32)
+!15 = !{i32 2, !"Dwarf Version", i32 4}
+!16 = !{i32 2, !"Debug Info Version", i32 3}
+!17 = !{i32 1, !"wchar_size", i32 4}
+!18 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/uchar.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   unsigned char a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global i8 0, align 1, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   15
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   8                       # 0x8
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "unsigned char"         # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIBasicType(name: "unsigned char", size: 8, encoding: DW_ATE_unsigned_char)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)"}

test/DebugInfo/BTF/uint.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   unsigned a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global i32 0, align 4, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   14
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "unsigned int"          # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIBasicType(name: "unsigned int", size: 32, encoding: DW_ATE_unsigned)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/ulonglong.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   unsigned long long a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global i64 0, align 8, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   8
+; CHECK-NEXT:        .long   64                      # 0x40
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "long long unsigned int" # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIBasicType(name: "long long unsigned int", size: 64, encoding: DW_ATE_unsigned)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}

test/DebugInfo/BTF/union-array-typedef.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   typedef int _int;
+;   union t {char m[4]; _int n;} a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+%union.t = type { i32 }
+
+@a = common dso_local local_unnamed_addr global %union.t zeroinitializer, align 4, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!16, !17, !18}
+!llvm.ident = !{!19}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   120
+; CHECK-NEXT:        .long   120
+; CHECK-NEXT:        .long   41
+; CHECK-NEXT:        .long   1                       # BTF_KIND_UNION(id = 1)
+; CHECK-NEXT:        .long   83886082                # 0x5000002
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   5
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   0                       # BTF_KIND_ARRAY(id = 2)
+; CHECK-NEXT:        .long   50331648                # 0x3000000
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   3
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   7                       # BTF_KIND_INT(id = 3)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   32                      # 0x20
+; CHECK-NEXT:        .long   27                      # BTF_KIND_INT(id = 4)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   1
+; CHECK-NEXT:        .long   16777224                # 0x1000008
+; CHECK-NEXT:        .long   32                      # BTF_KIND_TYPEDEF(id = 5)
+; CHECK-NEXT:        .long   134217728               # 0x8000000
+; CHECK-NEXT:        .long   6
+; CHECK-NEXT:        .long   37                      # BTF_KIND_INT(id = 6)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   16777248                # 0x1000020
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .byte   116                     # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   109                     # string offset=3
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .byte   110                     # string offset=5
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "__ARRAY_SIZE_TYPE__"   # string offset=7
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "char"                  # string offset=27
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "_int"                  # string offset=32
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .ascii  "int"                   # string offset=37
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 2, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = distinct !DICompositeType(tag: DW_TAG_union_type, name: "t", file: !3, line: 2, size: 32, elements: !7)
+!7 = !{!8, !13}
+!8 = !DIDerivedType(tag: DW_TAG_member, name: "m", scope: !6, file: !3, line: 2, baseType: !9, size: 32)
+!9 = !DICompositeType(tag: DW_TAG_array_type, baseType: !10, size: 32, elements: !11)
+!10 = !DIBasicType(name: "char", size: 8, encoding: DW_ATE_signed_char)
+!11 = !{!12}
+!12 = !DISubrange(count: 4)
+!13 = !DIDerivedType(tag: DW_TAG_member, name: "n", scope: !6, file: !3, line: 2, baseType: !14, size: 32)
+!14 = !DIDerivedType(tag: DW_TAG_typedef, name: "_int", file: !3, line: 1, baseType: !15)
+!15 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!16 = !{i32 2, !"Dwarf Version", i32 4}
+!17 = !{i32 2, !"Debug Info Version", i32 3}
+!18 = !{i32 1, !"wchar_size", i32 4}
+!19 = !{!"clang version 8.0.0 (trunk 345296) (llvm/trunk 345297)"}

test/DebugInfo/BTF/ushort.ll

+; RUN: llc -march=bpfel -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+; RUN: llc -march=bpfeb -filetype=asm -o - %s | FileCheck -check-prefixes=CHECK %s
+
+; Source code:
+;   unsigned short a;
+; Compilation flag:
+;   clang -target bpf -O2 -g -S -emit-llvm t.c
+
+@a = common dso_local local_unnamed_addr global i16 0, align 2, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!7, !8, !9}
+!llvm.ident = !{!10}
+
+; CHECK:             .section        .BTF,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   16
+; CHECK-NEXT:        .long   1                       # BTF_KIND_INT(id = 1)
+; CHECK-NEXT:        .long   16777216                # 0x1000000
+; CHECK-NEXT:        .long   2
+; CHECK-NEXT:        .long   16                      # 0x10
+; CHECK-NEXT:        .byte   0                       # string offset=0
+; CHECK-NEXT:        .ascii  "unsigned short"        # string offset=1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .section        .BTF.ext,"",@progbits
+; CHECK-NEXT:        .short  60319                   # 0xeb9f
+; CHECK-NEXT:        .byte   1
+; CHECK-NEXT:        .byte   0
+; CHECK-NEXT:        .long   24
+; CHECK-NEXT:        .long   0
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   4
+; CHECK-NEXT:        .long   8                       # FuncInfo
+; CHECK-NEXT:        .long   16                      # LineInfo
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "a", scope: !2, file: !3, line: 1, type: !6, isLocal: false, isDefinition: true)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/tmp")
+!4 = !{}
+!5 = !{!0}
+!6 = !DIBasicType(name: "unsigned short", size: 16, encoding: DW_ATE_unsigned)
+!7 = !{i32 2, !"Dwarf Version", i32 4}
+!8 = !{i32 2, !"Debug Info Version", i32 3}
+!9 = !{i32 1, !"wchar_size", i32 4}
+!10 = !{!"clang version 8.0.0 (trunk 344789) (llvm/trunk 344782)"}