<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/134285>134285</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            `-fdebug-types-section -gdwarf-3` crashes Clang with assertions
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang,
            crash-on-valid
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          cjdb
      </td>
    </tr>
</table>

<pre>
    **Source**

```cpp
struct A {};
struct B { A a; };
namespace N { using ::A; }
```

**Invocation**

```
clang -fdebug-types-section -gdwarf-3 crash.cpp
```

**Output**

```
Invalid form for specified DWARF version
UNREACHABLE executed at /root/llvm-project/llvm/lib/CodeGen/AsmPrinter/DIE.cpp:84!
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: /opt/compiler-explorer/clang-assertions-20.1.0/bin/clang++ -gdwarf-4 -g -o /app/output.s -mllvm --x86-asm-syntax=intel -fno-verbose-asm -S --gcc-toolchain=/opt/compiler-explorer/gcc-14.2.0 -fcolor-diagnostics -fno-crash-diagnostics -fdebug-types-section -gdwarf-3 <source>
1.      <eof> parser at end of file
2.      Code generation
 #0 0x0000000003e64af8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x3e64af8)
 #1 0x0000000003e627b4 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x3e627b4)
 #2 0x0000000003daec88 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x0000765056e42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x0000765056e969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x0000765056e42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x0000765056e287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x0000000003dba5ea (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x3dba5ea)
 #8 0x0000000004d99d59 llvm::DIEAbbrev::Emit(llvm::AsmPrinter const*) const (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x4d99d59)
 #9 0x0000000004d9a2f7 llvm::DIEAbbrevSet::Emit(llvm::AsmPrinter const*, llvm::MCSection*) const (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x4d9a2f7)
#10 0x0000000004dc9b23 llvm::DwarfDebug::endModule() (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x4dc9b23)
#11 0x0000000004d844cd llvm::AsmPrinter::doFinalization(llvm::Module&) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x4d844cd)
#12 0x00000000037ac4dd llvm::FPPassManager::doFinalization(llvm::Module&) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x37ac4dd)
#13 0x00000000037b6fd6 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x37b6fd6)
#14 0x00000000041224a0 clang::emitBackendOutput(clang::CompilerInstance&, clang::CodeGenOptions&, llvm::StringRef, llvm::Module*, clang::BackendAction, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>, clang::BackendConsumer*) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x41224a0)
#15 0x00000000047f7a50 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x47f7a50)
#16 0x000000000683fc7c clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x683fc7c)
#17 0x00000000047f7e58 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x47f7e58)
#18 0x0000000004abdd25 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x4abdd25)
#19 0x0000000004a407de clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x4a407de)
#20 0x0000000004babd8e clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x4babd8e)
#21 0x0000000000cfe40f cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0xcfe40f)
#22 0x0000000000cf5e9a ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#23 0x000000000483e749 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#24 0x0000000003daf134 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x3daf134)
#25 0x000000000483ed3f clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (.part.0) Job.cpp:0:0
#26 0x0000000004801bad clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x4801bad)
#27 0x0000000004802c2e clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x4802c2e)
#28 0x000000000480a765 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0x480a765)
#29 0x0000000000cfb213 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0xcfb213)
#30 0x0000000000bc3694 main (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0xbc3694)
#31 0x0000765056e29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#32 0x0000765056e29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#33 0x0000000000cf5945 _start (/opt/compiler-explorer/clang-assertions-20.1.0/bin/clang+++0xcf5945)
```

**Clang details**

```
clang version 20.1.0 (https://github.com/llvm/llvm-project.git 24a30daaa559829ad079f2ff7f73eb4e18095f88)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/compiler-explorer/clang-assertions-20.1.0/bin
Build config: +assertions
ASM generation compiler returned: 0
clang version 20.1.0 (https://github.com/llvm/llvm-project.git 24a30daaa559829ad079f2ff7f73eb4e18095f88)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /opt/compiler-explorer/clang-assertions-20.1.0/bin
Build config: +assertions
Compiler did not produce an executable
Execution build compiler returned: 0
```
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJzsWk1z4zbS_jXwBUUVBX4ffKBl641TmcQ1ct49qkAApJEhAS4AeuT99VsAKJNUZCfetbKH3SnPmCSA7qefbnQ3icFa80Ywdg2SG5DcXuHBPEl1TX6j1VUl6cs1QCVA5U4OijB_DUL3k4b-h_Q9CEtt1EAMLCHIbkB2C6Kb6eGNfQhLiEFkL8dBgTume0wY_NmND5qLBoKoBFFZHmfO9IxqHYR78SwJNlyKs5BAWJIWiwYGNWXV0ATmpWc60IzYJTBo6Hes6iCCRGH9tPIWnFX0y2D6wbyl5F4845ZTWEvV2X-g7hnhNWcU3v6t_LqFz0xpCzIsf_356125-aG8-ekOsgMjg2EUYgMB2iopDUDbtn3ugl7J3xg53tpfvAJou5GU_R8TAG1L3T0oLgxTAG1v7-8c-KjMY4DWICwffrord3dQD1XHDcSwGhqoWC-VgUbCJ2N6bRlGW4C2DTdPQ7UispupW4LgWg9MA7SFWFDIBWkHyqB5Yp45WGHyzShsI2MDe8V6JQnTmlGox4DZuJVYa0k4tjarQUBNFO_NCoTlzmDyDdKhs0aAsAxXICwelGwU7iBWzdAxYSxkS5TsLSYiu563TAXs0LdSOSKctwOsNVPWwzpA4Wq9CgHaVlwcxwG6Aejm1fsxDBoYSCsY970V73y90jDoLA0wCA55GmDdBfpFGHwA0a0lvoVBLWTwzFQlNbPjMNjBIGgICYyULXnCXIDo9l3AdvI6XqFVCIOayFaqgHLcCKkNJ9prcBSfPH4_nEG0GXmP7kBYri2ZINowWYPoDvZYaaZs0DFBoaxhzVsGwhLZaTbCYMMEU35bhZbxKIThITz-iVga4zqHLlTcNtUv2l-4kHS-fPTRkE-TFP6-l9oohjuAUhsRXBiACghQ_llOBegmPIz4ACpG9OsT9Cir4nPoNy3DYuh_ETveCNwClA_CZUUKW2lVXASrRTNhRQusFDOS53BjI-ArI_KZqRcP7gcsaGtV5iOLizkbKQw7mDEphO6vlx-N8rM0CZOUxShB4WiVTzGHPN2ncdByMRyCRgx-gKy0XKUOslsyAY6XAou0qAnszZNimO6_8bb9mHS3fpKenMKNsxQ22lHwUdhxlk6C06VglGd1BHFlE-SHxLqFk9hs6b4KJwx_ftB4uZPWfK41pkVBk2IW4Lf3d2VVKfbsb-86bhY7c6olkEihfZkr_PWngx_hTeCLE_AY1dk58DtmPoJ_M5PxZbPzOfLSllns3jKbdsKlZaSoUDS3zGbrW5vI_T0T9IukQ8scsM_PNSOCCd96iS-PY0LhOVr9PZVbLnDL_zE2XDMPHHGnl8HtkE24lzkywySmc9zbhwes9RcscPOfhj6Cm6BHS-hVWtN0Br1lDSYvYy2djLjv-nYsosNfit7hm9DHi4BZIxTjEPpVPoI7bm4w-cYEPTbM-Wx4M2K6F9pgQdjYBixmuP72l97hG8cna3dGcdF8ZfXJ9h5JKE-kjVDKcevPl9wLowbNn9lXVm-EeTAKRJtp-LkeW4Itb9nuRRvW2VYKbaA21I8Mgv99YPv-ZKXtcvrvihu2P_Y6s0WU1XhozZ6ylhn2Bwuju1Hn703aSKGHzjq1vMiO866dHJ8sHJ_VGU7C92C5h75FeVRY6Nbtu18FP4mIcvc4tiqXyh0e62RJOrckzaOaZGRuyYNtjsvd4xLnjnV4jMZKynb6_fmIR0wT4uyUe5bkZ_bMGOW-QvoXy2PgX6aaeCQTzmUTgitKUTLHuVXW06_bcQ70UhA9iAnistXAcZhRBt9LUGfZfNumC8WwB_pqBlr2FRWuaL4wYwQ8WTN9JHk_HV8mmXiAE_xF2xGSmsVhDQlZ7zv7wrxo7JTCLzbdRxvyhGfd3ZgXF8_QBj5LTi9khYc5GYFOjEhYgeGR-M360WWHmSm7Drft_zNi5FjNz1h0Uu2sjDE7Hue5-KKKPzN18m5nMS2aiziPWBYXjpOZ0HoQLlb3ytHqRv32c_XGTiG4bStMvu1rYWFOAeMVj8GzWW9k12FBT3fyWfe9VkDpSjtuF7VvquuvNe91wX5PDof12t9UWHNi6yO3mByFi8n2wd4ozI0-Dp-Iw21rN4NUs3E7pZxy-vSK4JcAlLW4qygGKJuoQvnxm8CPsjrjjPjkRb5eR_OPDude1_3I10HscM3alwWX7_vtEs2fhzxFfHIaXTSq4X9zdFjKVz1WxrL4VhikS9bCdYXpm6w5t-HflccjlYvsfbLQTphlic07OuZTy0VXc7E3Y2_3FEvZCSuIIPZRVn6UlX6bkh9l9RPXZkHJe9n4NQR6zK333Ve1P8_iGCd_DZeWrYnL_IRLnKXJW7hvZ9eLLuFMe_CWD_5CLi_QjHh-JvaKkzpeoXXkkR7bkSN6l03K331beqtKf34DYqG9Al9-kg8rEqVFDC3kT9fsZU-a1yefTgtafPATslsyCUSnAlkcwv3ertlrg5XZz-z60ypYPFMRnbZrRZxAL_wCnrLSR93nDhM37kySMoN5q98_uBwPDqFXaaF-7Oxu1XADUYyjkGKMk6TIUYFpmBU1quusziJWxWydh0VS5-O73CNWjfvUCkeSB_FNyO9iRnZYPrrv-7CTlLV2ai81P7iTUG1w2zJ6a3f-v3VaF5Y3A29dXqh544XdTJNBWJa7L7OjKnhUARUzgxLMJiH4Pyr_FJXHd0FIOYVCGtgrSQfCIBbjMTWu3CGhrxqWx2oU-Qbpr7F8Ra8jWkQFvmLX6yyOshAlWXT1dJ1EqMiqfI3TtAhpldAM5RTjNKUsKnIaXfFrFKIkjMNoncVFhFYojRBOSVVQHEc4ZyAOWYd5u7J-WknVXLmD6ut1FKM8uWpxxVrt_kcDQuMuRQBt7J07U5UicAf39nFye6Wunb-rodEgDluujZ4kG25adg3S8A8OX0Ea-kNxpqHf6N-5eYIT21eDaq__9RP40bbna_TPAAAA___ZEzmR">