<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/130850>130850</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Clang crashes on inline function with `target_clones` attribute
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang
      </td>
    </tr>

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

    <tr>
      <th>Reporter</th>
      <td>
          bi6c
      </td>
    </tr>
</table>

<pre>
    Clang crashes with an UNREACHABLE assertion when compiling code that combines an extern inline function with a subsequent redeclaration that adds the target_clones attribute. The error occurs during the LLVM IR generation phase.

Compiler Explorer: [https://godbolt.org/z/Wa76Gqchn](https://godbolt.org/z/Wa76Gqchn)

(Generated by fuzzer)

**Code:**
```c
#if __STDC_VERSION__ >= 199901L
#define inline __attribute__((gnu_inline)) inline
#endif

extern inline int func1(void) { return 0; }
inline int __attribute__((target_clones("default,avx"))) func1(void) { return 1; }
```

**Observed Behavior:**

```
<source>:6:27: warning: attribute declaration must precede definition [-Wignored-attributes]
    6 | inline int __attribute__((target_clones("default,avx"))) func1(void) { return 1; }
      |                           ^
<source>:5:19: note: previous definition is here
    5 | extern inline int func1(void) { return 0; }
 |                   ^
None multiversion type isn't valid here
UNREACHABLE executed at /root/llvm-project/clang/lib/CodeGen/CodeGenModule.cpp:1961!
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-trunk/bin/clang -gdwarf-4 -g -o /app/output.s -mllvm --x86-asm-syntax=intel -fno-verbose-asm -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics <source>
1.      <eof> parser at end of file
2.      <source>:6:58: LLVM IR generation of declaration 'func1'
3.      <source>:6:58: Generating code for declaration 'func1'
 #0 0x0000000003e6dcc8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3e6dcc8)
 #1 0x0000000003e6b984 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3e6b984)
 #2 0x0000000003db8298 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x0000709700a42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x0000709700a969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x0000709700a42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x0000709700a287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x0000000003dc3bfa (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3dc3bfa)
 #8 0x00000000043dedca getMangledNameImpl(clang::CodeGen::CodeGenModule&, clang::GlobalDecl, clang::NamedDecl const*, bool) CodeGenModule.cpp:0:0
 #9 0x00000000043f57a6 clang::CodeGen::CodeGenModule::UpdateMultiVersionNames(clang::GlobalDecl, clang::FunctionDecl const*, llvm::StringRef&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x43f57a6)
#10 0x000000000442d4ca clang::CodeGen::CodeGenModule::GetOrCreateLLVMFunction(llvm::StringRef, llvm::Type*, clang::GlobalDecl, bool, bool, bool, llvm::AttributeList, clang::CodeGen::ForDefinition_t) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x442d4ca)
#11 0x0000000004430288 clang::CodeGen::CodeGenModule::GetAddrOfFunction(clang::GlobalDecl, llvm::Type*, bool, bool, clang::CodeGen::ForDefinition_t) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4430288)
#12 0x0000000004430609 clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4430609)
#13 0x000000000443364b clang::CodeGen::CodeGenModule::EmitMultiVersionFunctionDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x443364b)
#14 0x000000000442b9e5 clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x442b9e5)
#15 0x000000000442bdcb clang::CodeGen::CodeGenModule::EmitGlobal(clang::GlobalDecl) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x442bdcb)
#16 0x0000000004436183 clang::CodeGen::CodeGenModule::EmitTopLevelDecl(clang::Decl*) (.part.0) CodeGenModule.cpp:0:0
#17 0x00000000048346c6 (anonymous namespace)::CodeGeneratorImpl::HandleTopLevelDecl(clang::DeclGroupRef) ModuleBuilder.cpp:0:0
#18 0x0000000004824684 clang::BackendConsumer::HandleTopLevelDecl(clang::DeclGroupRef) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4824684)
#19 0x000000000642f404 clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x642f404)
#20 0x0000000004830ea8 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4830ea8)
#21 0x0000000004af9d95 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4af9d95)
#22 0x0000000004a7d56e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4a7d56e)
#23 0x0000000004be7f2e clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4be7f2e)
#24 0x0000000000d535a7 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xd535a7)
#25 0x0000000000d4a36a ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#26 0x0000000004879539 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
#27 0x0000000003db8744 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3db8744)
#28 0x0000000004879b2f 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
#29 0x000000000483c07d clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x483c07d)
#30 0x000000000483d0fe clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x483d0fe)
#31 0x0000000004845015 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4845015)
#32 0x0000000000d4f843 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xd4f843)
#33 0x0000000000c17374 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xc17374)
#34 0x0000709700a29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#35 0x0000709700a29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#36 0x0000000000d49e15 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xd49e15)
clang: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134
```
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJzkWtty2ziTfhr4BiUVCZ4vfEHLdiZTzqHiTOZSBQKghA0FcABQkefptwBQ5sGSN85qZ6fqdykViQC6v_660d0EibXmG8HYNUhuQHJ7hTuzleq64im5qiR9ul41WGwgUVhvmYY_uNlCLOAfH7_clavfypuHO4i1ZspwKeCPLROQyF3LG24XScqg2WJjr1VcMG2XsoNhSkAuGi4YrDtB_FonGequ0uyvjgkDFaOMNFhhN-7kYEo1NFsGDVYbZtakkU6qMYpXnWFL-HXLIFNKKigJ6ZSGtFMWi1308PDtA3z_BW6YYL3Udos1W4KgBEG5csCZgneHtpGKKRCVECQ3W2NaDaISoHuA7jeSVrIxS6k2AN3_DdD9nzhL3_1FtgIktwDlPz8dFV4xQPk7D4lRWD3Buvv7b6ZGw_azkpQ5qe4TlCAN_Ie4KRGv4Xr9-PV2tf529-Xx_aeP6zUE0R2IbmFYFEUQPvh5lNWW957-9fqZu_UaoBygfCO6tR-1CFDRT_WrmaC89rCmfuTCOF-GAOV7yaldCLIbqJjplIABiG4gyG5BUI4WnNA-cay7hCircdcYgFZ4fwAIeVhWwSsKw0HhM1NjOj9Vmqk9o_CGbfGeSzXhdrYoWmnZKcIcn2UKohJlNjh-YCW42Nivz4bAcdDuOm1gqxhh1A7UXHB3HSQ3iz_5RkjF6OJ5qbYBFJQQQphCkK3gP04VdH9W9fk_kNy95CQBURkWlgghjY1Ta_Wey06PzeYabplivaLEKfrVMDqD0qP7KAWDu64xfM-UdunjqWWQawFQZuAeN5weoYxTGTsw0tldiA0E6F5JaQC6b5r9btEq-V-M2J_EZkR7mVcA3dt9-Y6J4dsHSbuGLUnbOk7SEKAQBOXnh7vy8c7mtx03EMOq20DFWqkMNBLOkgY3265aErnrtb8EwbXurNfvIRYUckGaziVb5lM1rDD5bhQmDKCV9UWrJGFaMwp7t6GVW4m1loS7zKM6ATVRvDU2IT4aTL5D2u2sGSAogyUIis9KbhTeQaw23Y4Jo12KRPeydcT0CXTBjgm0J2vxXCL0wqhOfAfovuLiOAwXG_oDq3oRw8UGLqSViNvWyu1M25mlhoudtR8uFoc8XWC9W-gnYfABRLdcGNbARS3kYs9UJTWz43DxCBeLDSELI2VDtpgLEN2-itRO1gK3eisNXNRENlItKMcbIbXhRHsdjt3J5clOCMrQ8gSiFZM1iO5gi5VmysYTExTKGta8sVGH-mnzxJLkltITlUrWk8wCUNbvkwwEZfSqtL64PJfkWqpXZEGAogAGh-D4F7GUEpJDF4hRCaJSP2n_5bPiwrhI-epjLR8mKfxjLbVRDO8ASm28cWHcfrap6n8ZMgDdBIcemC-UFnY4g10VeXwK9qphWHTtJ_HINwI3AOWdcG0QhY20wi8L0sIYQKIJSFrlqMjhyobVF0bknqknj-o3LGhjdeU9b5M5KykMO5g-zQTun5cf9fKzoMiCAMcoQUFvjs9Yhzxdp_Gi4aI7LDai8wNkqeUydZDdkgFwPBVYpEVNYGu2imG6_s6b5m3S3fpBejKHG2cp3GhHwVthx1k6CE6nglGe1RHElU24bxLrFg5is6n7SFTV-ILR4gUO6vKxujiijBIMN8x8wGLTMPoR79j7XWtD2Avx8d3XpPEPX5b6nTia-66RFW5uGWlmA1Y0tdchkUIb1xytYCVl44LxRLEbR2ExxV0nGU7hz0F0l_5oKTbsgy3h33wJt3j01M6z2O_7u4oX8Idk8GjsfcEXVjtKLrjhe2P79h1F4SSZxjGiMcFvoeIdM5_USjFsmK0LR9smyXZkzdjIr08t6y0_S5v36Mv_BynlsfN84JbI1Vnw91LdPnd768sm-564gdZwSmsUoDx_I60lpepTPSL0LEknKZ0z9v9DizN8oAXNaUmD4i203O248bYPm-iI_ecY8te_4abzRF3Y2jQoBmujmbVRGldvtXacZP6dNlurBpvjWT6pCpb8mof_VVY6OwYrk7mVlLzZsx7vedsujJ-SkZfSWWSmYR69Ff9X2T6wPevRjq3wV44uWLZYmWXwP9VlC2vSvsR5FKcktSKwkOJpZ-_Xha2zrevmiwk6ew8hles23GXfoL6O8Z2SXevKUgE9ppuON5SpE9CmrU6O4jSPx4zdYPKdCbqSQnc7dzr3CyAu53APcHD4pONJY1THwQT-Z3snWD5-neJ7ZDvcN2XTcnJBqD2YZ6gomAVBwPCp0ln6sujD0Z-MlMdKeWEuHYQB4LS247qgxSTF3St7-yPoCYQXx-a1D9imBRZnNEnZlDyv7b3QBgvCTvN33phLt6Me4YB_WjIrltVogr9HOpixlwS_RP3CzEsXBI9swD0pewFNogRnkJBwvcN82gyXSuEnu9-jFdliNdwARHeuTZtcQyvoDxovC9_jG9AnU_QxjlIMj1Svwq9uz48b-h1umm-MPGfcE6aks85UyqY_FjjOc6FEFd-fSrhoWqLyrEiiwpExEnp8PrNWjk836reYP2UCUUlw01SYfF_XwsIcQsQr7sNlFa7kbocFne_Wk37Tpp8nW6sdWwJO3e1YDM6pzwvWa3I4hKH_UWHNyVq76T2Fk8n2wtoozI0-Ds_E4aax4S_VaNxOGd0AuMDxhLslAGUN3lUUA5QNVKH8eLT0u6xOOCObHwtl8fjs6tThjx_50olHXLPmacLl63676AGXxzqEej4PqwrV8D85LGYt2mn_F7OaTIKMnmXN-Qu_qH1HKieJerbQThilh9UrOsZTy0mTMjLsYh2ANfg5iKJ5i0KDmr2Vjt9lpc9z8busHrg2Ey5ey7_Pvm8xt253p7I_T18fIP_HJFqaBhKnbVQeJ0GYnAN8O_o-aQFO1P5z5P-DJF60-3TEDLShWa2u87i_dTv2GkfYLnGUL84Wz1Xiy3UXDtOAeNLTBSTMoiyGFuvlVHqhg8rZUwFU0OKNjxnckkFgMhfI4gCu13bNWhuszHpk0E-rYPFIRTpzbMHCBHrhl_SNFeuVHuPav5Jiv_gHnnXf8kPSR3iNecOofwmGHbjxD-rCKLa4Os3gYg-NhJoxyEcNeTF-bcU_I2d2g9mV45cYruh1RIuowFfsOsziMIsClMZX2-sIJxWKMYsZjpKc5TlOE1xFFBGSBGEcX_FrFKAkiMIQhUkWx8s8oDFLkzBPAhblIQVxwHaYN0sb_kupNlfu0fR1GAV5Elw1uGKNdm8XIdSThEBye6Wu3RPtqttoEAcN10YPIgw3DZu9eiTPvDME0mD6JkQaDG9jXHWquf71h-u9Eftr9N8BAAD__zYSeGo">