[lldb] fixing #61727 fixing incorrect variable displaying with DW_OP_div

[jwnhy]

Summary

This patch resolves an issue where a value
is incorrectly displayed if it is represented
by DW_OP_div.

This issue is caused by lldb evaluating
operands of DW_OP_div as unsigned
and performed unintended unsigned
division.

This issue is resolved by creating two
temporary signed scalar and performing
signed division.

[JDevlieghere]

The change looks good: it matches what the DWARFv5 standard says:

The DW_OP_div operation pops the top two stack values, divides the former second entry by the former top of the stack using signed division, and pushes the result.

Can you please add a regression test for the corrected behavior?

[jwnhy]

Update the patch to include a small
regression test.

[jwnhy]

Thanks a lot for the suggestion.
I added a assembly testcase for "DW_OP_div".
Also, since I don't have the permission to push,
if the patch is good to you, could you please
help me merge it?

Ping.

[jwnhy]

Ping!

[Michael137]

LGTM

lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_div-with-signed.s

4

other tests use llvm-mc as the assembler
E.g., llvm-mc -filetype=obj -o %t -triple x86_64-pc-linux %s

I think it'll marginally speed things up

7

Can you paste the source code here which you used to derive this test case? For future readers

[jwnhy]

Updated the patch to include the original code.

Could you please help me push it to the main codebase?, as I don't have the push right to the repo.

[jwnhy]

lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_div-with-signed.s

4

There are some issues on llvm-mc, it complains about .loc directives.
So I guess I will just go with Clang...

7

Update the patch to include the original sources.

[Michael137]

@jwnhy Let me know which name and email I should attribute the patch to

[jwnhy]

In D147370#4309481, @Michael137 wrote:

@jwnhy Let me know which name and email I should attribute the patch to

Oh, sorry.
I am LU Hongyi, and the email is [e-mail], my github account is also jwnhy.

Thank you very much.

[aprantl]

This test is failing on Darwin: https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/lastFailedBuild/testReport/lldb-shell/SymbolFile_DWARF_x86/DW_OP_div_with_signed_s/

https://green.lab.llvm.org/green/view/LLDB/job/lldb-cmake/lastFailedBuild/

ld: unknown option: --hash-style=gnu
clang: error: linker command failed with exit code 1 (use -v to see invocation)

[aprantl]

I'll try adding a # REQUIRES: lld

[asl]

This seems to fail on ARM: https://lab.llvm.org/buildbot/#/builders/17/builds/37130

[asl]

The test seems to rely on the presence of the linker for the desired target platform, so cannot be used on cross-compile environment.

******************** TEST 'lldb-shell :: SymbolFile/DWARF/x86/DW_OP_div-with-signed.s' FAILED ********************
Script:
--
: 'RUN: at line 3';   /home/tcwg-buildbot/worker/lldb-arm-ubuntu/build/bin/clang --target=specify-a-target-or-use-a-_host-substitution --target=x86_64-pc-linux -o /home/tcwg-buildbot/worker/lldb-arm-ubuntu/build/tools/lldb/test/Shell/SymbolFile/DWARF/x86/Output/DW_OP_div-with-signed.s.tmp /home/tcwg-buildbot/worker/lldb-arm-ubuntu/llvm-project/lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_div-with-signed.s
: 'RUN: at line 4';   /home/tcwg-buildbot/worker/lldb-arm-ubuntu/build/bin/lldb --no-lldbinit -S /home/tcwg-buildbot/worker/lldb-arm-ubuntu/build/tools/lldb/test/Shell/lit-lldb-init-quiet /home/tcwg-buildbot/worker/lldb-arm-ubuntu/build/tools/lldb/test/Shell/SymbolFile/DWARF/x86/Output/DW_OP_div-with-signed.s.tmp -o "b f" -o "r" -o "c" -o "c" -o "expression -T -- i"  -o "exit" | /home/tcwg-buildbot/worker/lldb-arm-ubuntu/build/bin/FileCheck /home/tcwg-buildbot/worker/lldb-arm-ubuntu/llvm-project/lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_div-with-signed.s
--
Exit Code: 1
Command Output (stderr):
--
/usr/bin/ld: unrecognised emulation mode: elf_x86_64
Supported emulations: armelf_linux_eabi armelfb_linux_eabi
clang: error: linker command failed with exit code 1 (use -v to see invocation)

[Michael137]

In D147370#4313196, @asl wrote:

This seems to fail on ARM: https://lab.llvm.org/buildbot/#/builders/17/builds/37130

Investigating

[Michael137]

Reverted for now until we find fix for test

[jwnhy]

Update the testcase to resolve cross-platform issue.
This new testcase is hand-crafted with DW_OP_div.
Therefore, it no longer require to be linked and executed.
Just directly call lldb on this object file and use "p g" to
see if the value represented by DW_OP_div is correct or not.

[jwnhy]

I have updated the testcase in the patch and remove the linker stage (using "-c").
But I don't have an Arm devices, can anyone help me test it?

[jwnhy]

In D147370#4314617, @jwnhy wrote:

I have updated the testcase in the patch and remove the linker stage (using "-c").
But I don't have an Arm devices, can anyone help me test it?

Asked one of my friend to tested on M1 Arm, "clang -c" works.

[Michael137]

I tried the new test case on my Mac but it's now hitting an assertion:

******************** TEST 'lldb-shell :: SymbolFile/DWARF/x86/DW_OP_div-with-signed.s' FAILED ********************
Script:
--
: 'RUN: at line 2';   /Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang --target=specify-a-target-or-use-a-_host-substitution -c --target=x86_64-pc-linux -o /Users/michaelbuch/Git/lldb-build-main-no-mod
ules/tools/lldb/test/Shell/SymbolFile/DWARF/x86/Output/DW_OP_div-with-signed.s.tmp /Users/michaelbuch/Git/llvm-project/lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_div-with-signed.s
: 'RUN: at line 3';   /Users/michaelbuch/Git/lldb-build-main-no-modules/bin/lldb --no-lldbinit -S /Users/michaelbuch/Git/lldb-build-main-no-modules/tools/lldb/test/Shell/lit-lldb-init-quiet /Users/michaelbuch/Git
/lldb-build-main-no-modules/tools/lldb/test/Shell/SymbolFile/DWARF/x86/Output/DW_OP_div-with-signed.s.tmp -o "expression -T -- g" -o "exit" | /Users/michaelbuch/Git/lldb-build-main-no-modules/bin/FileCheck /Users
/michaelbuch/Git/llvm-project/lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_div-with-signed.s
--
Exit Code: 1

Command Output (stderr):
--
Assertion failed: ((!RootFile.Name.empty() || MCDwarfFiles.size() >= 1) && "No root file and no .file directives"), function emitV5FileDirTables, file MCDwarf.cpp, line 473.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.      Program arguments: /Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang --target=specify-a-target-or-use-a-_host-substitution -c --target=x86_64-pc-linux -o /Users/michaelbuch/Git/lldb-build-main-n
o-modules/tools/lldb/test/Shell/SymbolFile/DWARF/x86/Output/DW_OP_div-with-signed.s.tmp /Users/michaelbuch/Git/llvm-project/lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_div-with-signed.s
 #0 0x0000000109466660 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x104682660)
 #1 0x0000000109466bf8 PrintStackTraceSignalHandler(void*) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x104682bf8)
 #2 0x00000001094649d0 llvm::sys::RunSignalHandlers() (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x1046809d0)
 #3 0x0000000109465e10 llvm::sys::CleanupOnSignal(unsigned long) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x104681e10)
 #4 0x00000001093245c8 (anonymous namespace)::CrashRecoveryContextImpl::HandleCrash(int, unsigned long) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x1045405c8)
 #5 0x0000000109324a64 CrashRecoverySignalHandler(int) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x104540a64)
 #6 0x000000018ddc2a24 (/usr/lib/system/libsystem_platform.dylib+0x18042ea24)
 #7 0x000000018dd93c28 (/usr/lib/system/libsystem_pthread.dylib+0x1803ffc28)
 #8 0x000000018dca1ae8 (/usr/lib/system/libsystem_c.dylib+0x18030dae8)
 #9 0x000000018dca0e44 (/usr/lib/system/libsystem_c.dylib+0x18030ce44)
#10 0x0000000108c3ad04 llvm::MCDwarfLineTableHeader::emitV5FileDirTables(llvm::MCStreamer*, std::__1::optional<llvm::MCDwarfLineStr>&) const (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x103e5
6d04)
#11 0x0000000108c39ff8 llvm::MCDwarfLineTableHeader::Emit(llvm::MCStreamer*, llvm::MCDwarfLineTableParams, llvm::ArrayRef<char>, std::__1::optional<llvm::MCDwarfLineStr>&) const (/Users/michaelbuch/Git/lldb-build
-main-no-modules/bin/clang-17+0x103e55ff8)
#12 0x0000000108c3a178 llvm::MCDwarfLineTableHeader::Emit(llvm::MCStreamer*, llvm::MCDwarfLineTableParams, std::__1::optional<llvm::MCDwarfLineStr>&) const (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/c
lang-17+0x103e56178)
#13 0x0000000108c39920 llvm::MCDwarfLineTable::emitCU(llvm::MCStreamer*, llvm::MCDwarfLineTableParams, std::__1::optional<llvm::MCDwarfLineStr>&) const (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang
-17+0x103e55920)
#14 0x0000000108c397b4 llvm::MCDwarfLineTable::emit(llvm::MCStreamer*, llvm::MCDwarfLineTableParams) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x103e557b4)
#15 0x0000000108c80320 llvm::MCObjectStreamer::finishImpl() (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x103e9c320)
#16 0x0000000108c528e4 llvm::MCELFStreamer::finishImpl() (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x103e6e8e4)
#17 0x0000000108cb0b88 llvm::MCStreamer::finish(llvm::SMLoc) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x103eccb88)
#18 0x0000000108d51fb4 (anonymous namespace)::AsmParser::Run(bool, bool) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x103f6dfb4)
#19 0x0000000104e15b74 ExecuteAssemblerImpl((anonymous namespace)::AssemblerInvocation&, clang::DiagnosticsEngine&) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x100031b74)
#20 0x0000000104e117c8 ExecuteAssembler((anonymous namespace)::AssemblerInvocation&, clang::DiagnosticsEngine&) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x10002d7c8)
#21 0x0000000104e10190 cc1as_main(llvm::ArrayRef<char const*>, char const*, void*) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x10002c190)
#22 0x0000000104deb110 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x100007110)
#23 0x0000000104e008ac clang_main(int, char**, llvm::ToolContext const&)::$_0::operator()(llvm::SmallVectorImpl<char const*>&) const (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x10001c8ac)
#24 0x0000000104e00880 int llvm::function_ref<int (llvm::SmallVectorImpl<char const*>&)>::callback_fn<clang_main(int, char**, llvm::ToolContext const&)::$_0>(long, llvm::SmallVectorImpl<char const*>&) (/Users/mic
haelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x10001c880)
#25 0x000000010a6a9ac0 llvm::function_ref<int (llvm::SmallVectorImpl<char const*>&)>::operator()(llvm::SmallVectorImpl<char const*>&) const (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x1058c5
ac0)
#26 0x000000010a6a9a80 clang::driver::CC1Command::Execute(llvm::ArrayRef<std::__1::optional<llvm::StringRef>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>*, bool*) const::
$_1::operator()() const (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x1058c5a80)
#27 0x000000010a6a9a4c void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<std::__1::optional<llvm::StringRef>>, std::__1::basic_string<char, std::__1::char_traits<char
>, std::__1::allocator<char>>*, bool*) const::$_1>(long) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x1058c5a4c)
#28 0x0000000109324468 llvm::function_ref<void ()>::operator()() const (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x104540468)
#29 0x00000001093243ec llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x1045403ec)
#30 0x000000010a6a595c clang::driver::CC1Command::Execute(llvm::ArrayRef<std::__1::optional<llvm::StringRef>>, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char>>*, bool*) const (
/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x1058c195c)
#31 0x000000010a63d890 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x10585
9890)
#32 0x000000010a63db1c clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::__1::pair<int, clang::driver::Command const*>>&, bool) const (/Users/michaelbuch/Git/lldb-b
uild-main-no-modules/bin/clang-17+0x105859b1c)
#33 0x000000010a65a0d8 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::__1::pair<int, clang::driver::Command const*>>&) (/Users/michaelbuch/Git/lldb-build-main-no
-modules/bin/clang-17+0x1058760d8)
#34 0x0000000104dea6dc clang_main(int, char**, llvm::ToolContext const&) (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x1000066dc)
#35 0x0000000104e28918 main (/Users/michaelbuch/Git/lldb-build-main-no-modules/bin/clang-17+0x100044918)
#36 0x000000018da3bf28
clang: error: clang integrated assembler command failed with exit code 134 (use -v to see invocation)
clang version 17.0.0 (https://github.com/Michael137/llvm-project.git 398403259a5a42624d382517f05b21f106f591b8)
Target: x86_64-pc-linux
Thread model: posix
InstalledDir: /Users/michaelbuch/Git/lldb-build-main-no-modules/bin
clang: note: diagnostic msg: Error generating preprocessed source(s) - no preprocessable inputs.

--

********************
********************
Failed Tests (1):
  lldb-shell :: SymbolFile/DWARF/x86/DW_OP_div-with-signed.s


Testing Time: 129.47s
  Failed: 1

1 warning(s) in tests

[jwnhy]

Update the patch to pass the assertion.
Sorry I forget to enable these on my machine.

Given that said, this assertion seems pretty weird to me.
Since this assembly is also generated by clang (with handcrafted DWARF,
this assertion means that any assembly generated from a single file will
be rejected?

Anyway, I have added a dummy ".file 1" directive to pass
this assertion.

[jwnhy]

Update the patch for better naming.
The assertion is correct, I somehow delete
a file directive from the assembly generated
by clang.

It should work now...Thanks a lot for checking
this.

[Michael137]

Thanks for fixing

Just checked and it works on my M1 with assertions.

I relanded the latest version.

lldb/source/Expression/DWARFExpression.cpp

case DW_OP_div:
       } else {
         tmp = stack.back();
         if (tmp.ResolveValue(exe_ctx).IsZero()) {
           if (error_ptr)
             error_ptr->SetErrorString("Divide by zero.");
           return false;
         } else {
           stack.pop_back();
-          stack.back() =
-              stack.back().ResolveValue(exe_ctx) / tmp.ResolveValue(exe_ctx);
+          Scalar divisor, dividend;
+          divisor = tmp.ResolveValue(exe_ctx);
+          dividend = stack.back().ResolveValue(exe_ctx);
+          divisor.MakeSigned();
+          dividend.MakeSigned();
+          stack.back() = dividend / divisor;
           if (!stack.back().ResolveValue(exe_ctx).IsValid()) {
             if (error_ptr)
               error_ptr->SetErrorString("Divide failed.");
             return false;
           }
         }
       }
       break;

lldb/test/Shell/SymbolFile/DWARF/x86/DW_OP_div-with-signed.s

+  # Test handling of values represented via DW_OP_div
+  # RUN: %clang -c --target=x86_64-pc-linux -o %t %s
+  # RUN: %lldb %t -o "expression -T -- g" -o "exit" | FileCheck %s
+
+  # Failing case was:
+  # (int) $0 = 0
+  # CHECK: (int) $0 = 2
+  #
+  # This file is crafted by hand on the basis of a very simple C program.
+
+  # The original (NOT THIS FILE) error-triggering code is:
+  # #include "stdint.h"
+  # static volatile uint64_t g = 0;
+  #  static const int32_t f()
+  #  {
+  #    uint32_t i;
+  #        for (i = 0; (i != 10); i++)
+  #              ++g;
+  #        return 0;
+  #                  
+  #  }
+  #
+  #  int main()
+  #  {
+  #    f();
+  #    return 0;
+  #        
+  #  }
+  # When the above code is compiled by Clang 15.0.7 with -O1, it generates desired DW_OP_div for testing.
+  # Due to cross-platform issue, this case is hand-crafted for testing.
+  .text
+  .file "DW_OP_div-with-signed.c"
+  .globl  main                            # -- Begin function main
+  .p2align  4, 0x90
+  .type main,@function
+main:                                   # @main
+.Lfunc_begin0:
+  .loc  0 4 0                           # DW_OP_div-with-signed.c:4:0
+  .cfi_startproc
+# %bb.0:
+  .loc  0 5 5 prologue_end              # DW_OP_div-with-signed.c:5:5
+  xorl  %eax, %eax
+  retq
+.Ltmp0:
+.Lfunc_end0:
+  .size main, .Lfunc_end0-main
+  .cfi_endproc
+                                        # -- End function
+  .type g,@object                       # @g
+  .data
+  .globl  g
+  .p2align  2, 0x0
+g:
+  .long 3735928559                      # 0xdeadbeef
+  .size g, 4
+
+  .section  .debug_abbrev,"",@progbits
+  .byte 1                               # Abbreviation Code
+  .byte 17                              # DW_TAG_compile_unit
+  .byte 1                               # DW_CHILDREN_yes
+  .byte 37                              # DW_AT_producer
+  .byte 37                              # DW_FORM_strx1
+  .byte 19                              # DW_AT_language
+  .byte 5                               # DW_FORM_data2
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 114                             # DW_AT_str_offsets_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 16                              # DW_AT_stmt_list
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 27                              # DW_AT_comp_dir
+  .byte 37                              # DW_FORM_strx1
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 115                             # DW_AT_addr_base
+  .byte 23                              # DW_FORM_sec_offset
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 2                               # Abbreviation Code
+  .byte 52                              # DW_TAG_variable
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 2                               # DW_AT_location
+  .byte 24                              # DW_FORM_exprloc
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 3                               # Abbreviation Code
+  .byte 36                              # DW_TAG_base_type
+  .byte 0                               # DW_CHILDREN_no
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 62                              # DW_AT_encoding
+  .byte 11                              # DW_FORM_data1
+  .byte 11                              # DW_AT_byte_size
+  .byte 11                              # DW_FORM_data1
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 4                               # Abbreviation Code
+  .byte 46                              # DW_TAG_subprogram
+  .byte 0                               # DW_CHILDREN_no
+  .byte 17                              # DW_AT_low_pc
+  .byte 27                              # DW_FORM_addrx
+  .byte 18                              # DW_AT_high_pc
+  .byte 6                               # DW_FORM_data4
+  .byte 64                              # DW_AT_frame_base
+  .byte 24                              # DW_FORM_exprloc
+  .byte 122                             # DW_AT_call_all_calls
+  .byte 25                              # DW_FORM_flag_present
+  .byte 3                               # DW_AT_name
+  .byte 37                              # DW_FORM_strx1
+  .byte 58                              # DW_AT_decl_file
+  .byte 11                              # DW_FORM_data1
+  .byte 59                              # DW_AT_decl_line
+  .byte 11                              # DW_FORM_data1
+  .byte 73                              # DW_AT_type
+  .byte 19                              # DW_FORM_ref4
+  .byte 63                              # DW_AT_external
+  .byte 25                              # DW_FORM_flag_present
+  .byte 0                               # EOM(1)
+  .byte 0                               # EOM(2)
+  .byte 0                               # EOM(3)
+  .section  .debug_info,"",@progbits
+.Lcu_begin0:
+  .long .Ldebug_info_end0-.Ldebug_info_start0 # Length of Unit
+.Ldebug_info_start0:
+  .short  5                               # DWARF version number
+  .byte 1                               # DWARF Unit Type
+  .byte 8                               # Address Size (in bytes)
+  .long .debug_abbrev                   # Offset Into Abbrev. Section
+  .byte 1                               # Abbrev [1] 0xc:0x36 DW_TAG_compile_unit
+  .byte 0                               # DW_AT_producer
+  .short  29                              # DW_AT_language
+  .byte 1                               # DW_AT_name
+  .long .Lstr_offsets_base0             # DW_AT_str_offsets_base
+  .long .Lline_table_start0             # DW_AT_stmt_list
+  .byte 2                               # DW_AT_comp_dir
+  .byte 1                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .long .Laddr_table_base0              # DW_AT_addr_base
+  .byte 2                               # Abbrev [2] 0x23:0xb DW_TAG_variable
+  .byte 3                               # DW_AT_name
+  .long 60                              # DW_AT_type
+                                        # DW_AT_external
+  .byte 0                               # DW_AT_decl_file
+  .byte 1                               # DW_AT_decl_line
+  .byte 16                               # DW_AT_location
+  .byte 49
+  .byte 49
+  .byte 16                              # DW_OP_constu
+  .byte 255                             # 4294967295
+  .byte 255                             # 
+  .byte 255                             # 
+  .byte 255                             # 
+  .byte 15                              # 
+  .byte 26                              # DW_OP_and
+  .byte 17                              # DW_OP_consts
+  .byte 3                               # 3
+  .byte 28                              # DW_OP_minus
+  .byte 17                              # DW_OP_consts
+  .byte 127                             # -1
+  .byte 27                              # DW_OP_div
+  .byte 159
+  .byte 3                               # Abbrev [3] 0x2e:0x4 DW_TAG_base_type
+  .byte 4                               # DW_AT_name
+  .byte 5                               # DW_AT_encoding
+  .byte 4                               # DW_AT_byte_size
+  .byte 4                               # Abbrev [4] 0x32:0xf DW_TAG_subprogram
+  .byte 1                               # DW_AT_low_pc
+  .long .Lfunc_end0-.Lfunc_begin0       # DW_AT_high_pc
+  .byte 1                               # DW_AT_frame_base
+  .byte 87
+                                        # DW_AT_call_all_calls
+  .byte 5                               # DW_AT_name
+  .byte 0                               # DW_AT_decl_file
+  .byte 3                               # DW_AT_decl_line
+  .long 60                              # DW_AT_type
+                                        # DW_AT_external
+  .byte 0                               # End Of Children Mark
+.Ldebug_info_end0:
+  .section  .debug_str_offsets,"",@progbits
+  .long 28                              # Length of String Offsets Set
+  .short  5
+  .short  0
+.Lstr_offsets_base0:
+  .section  .debug_str,"MS",@progbits,1
+.Linfo_string0:
+  .asciz  "clang version 17.0.0 (https://github.com/llvm/llvm-project.git 1b18ab358a8e91e69a54f676c77f6a4cda8ba02d)" # string offset=0
+.Linfo_string1:
+  .asciz  "DW_OP_div-with-signed.c"       # string offset=105
+.Linfo_string2:
+  .asciz  "" # string offset=129
+.Linfo_string3:
+  .asciz  "g"                             # string offset=166
+.Linfo_string4:
+  .asciz  "int"                           # string offset=168
+.Linfo_string5:
+  .asciz  "main"                          # string offset=172
+  .section  .debug_str_offsets,"",@progbits
+  .long .Linfo_string0
+  .long .Linfo_string1
+  .long .Linfo_string2
+  .long .Linfo_string3
+  .long .Linfo_string4
+  .long .Linfo_string5
+  .section  .debug_addr,"",@progbits
+  .long .Ldebug_addr_end0-.Ldebug_addr_start0 # Length of contribution
+.Ldebug_addr_start0:
+  .short  5                               # DWARF version number
+  .byte 8                               # Address size
+  .byte 0                               # Segment selector size
+.Laddr_table_base0:
+  .quad g
+  .quad .Lfunc_begin0
+.Ldebug_addr_end0:
+  .ident  "clang version 17.0.0 (https://github.com/llvm/llvm-project.git 1b18ab358a8e91e69a54f676c77f6a4cda8ba02d)"
+  .section  ".note.GNU-stack","",@progbits
+  .addrsig
+  .section  .debug_line,"",@progbits
+.Lline_table_start0: