<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/113042>113042</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [clang] Assertion `RT->getDecl()->isUnion() && "RecordType is expected to be a union."' failed.
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang:frontend,
            crash-on-invalid,
            clang:frontend:fuzzer
      </td>
    </tr>

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

    <tr>
      <th>Reporter</th>
      <td>
          yijan4845
      </td>
    </tr>
</table>

<pre>
    **This testcase is generated by a fuzzer.**

Compiler Explorer: [https://godbolt.org/z/WWhd43dno](https://godbolt.org/z/WWhd43dno)

This invalid code will crash on Clang Assertion Trunk:
```cpp
inline int f2() {
  static struct { int a() { int 
    #pragma message "Any Messages"x; return ++x; } } obj;
}
```

It seems that this goes back to clang-3.6.

Stack dump:
```
clang++: /root/llvm-project/clang/lib/AST/ItaniumCXXABI.cpp:48: const clang::IdentifierInfo* {anonymous}::findAnonymousUnionVarDeclName(const clang::VarDecl&): Assertion `RT->getDecl()->isUnion() && "RecordType is expected to be a union."' failed.
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>:1:17: parsing function body 'f2'
3.      <source>:1:17: in compound statement ('{}')
 #0 0x0000000003bb93f8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3bb93f8)
 #1 0x0000000003bb70bc llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3bb70bc)
 #2 0x0000000003b046a8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x0000721d05a42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x0000721d05a969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x0000721d05a42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x0000721d05a287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x0000721d05a2871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #8 0x0000721d05a39e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #9 0x0000000007d7b154 (anonymous namespace)::ItaniumNumberingContext::getManglingNumber(clang::VarDecl const*, unsigned int) ItaniumCXXABI.cpp:0:0
#10 0x0000000006a28dde clang::Sema::BuildAnonymousStructOrUnion(clang::Scope*, clang::DeclSpec&, clang::AccessSpecifier, clang::RecordDecl*, clang::PrintingPolicy const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6a28dde)
#11 0x0000000006a29d89 clang::Sema::ParsedFreeStandingDeclSpec(clang::Scope*, clang::AccessSpecifier, clang::DeclSpec&, clang::ParsedAttributesView const&, llvm::MutableArrayRef<clang::TemplateParameterList*>, bool, clang::RecordDecl*&, clang::SourceLocation) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6a29d89)
#12 0x0000000006a2b954 clang::Sema::ParsedFreeStandingDeclSpec(clang::Scope*, clang::AccessSpecifier, clang::DeclSpec&, clang::ParsedAttributesView const&, clang::RecordDecl*&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6a2b954)
#13 0x00000000066c5567 clang::Parser::ParseSimpleDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, bool, clang::Parser::ForRangeInit*, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66c5567)
#14 0x00000000066c5839 clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66c5839)
#15 0x0000000006771ea2 clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6771ea2)
#16 0x0000000006772bd0 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6772bd0)
#17 0x0000000006773aa5 clang::Parser::ParseCompoundStatementBody(bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6773aa5)
#18 0x00000000067751fa clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x67751fa)
#19 0x0000000006688d83 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6688d83)
#20 0x00000000066bd43d clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66bd43d)
#21 0x000000000667cace clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x667cace)
#22 0x000000000667d28e clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x667d28e)
#23 0x0000000006684a23 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6684a23)
#24 0x000000000668590d clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x668590d)
#25 0x0000000006685db0 clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6685db0)
#26 0x0000000006677df2 clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6677df2)
#27 0x000000000452f368 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x452f368)
#28 0x00000000047ea629 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x47ea629)
#29 0x000000000476911e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x476911e)
#30 0x00000000048cfcfe clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x48cfcfe)
#31 0x0000000000cde1ef cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xcde1ef)
#32 0x0000000000cd5efa ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#33 0x0000000004573089 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
#34 0x0000000003b04b54 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3b04b54)
#35 0x000000000457367f 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
#36 0x0000000004538f7d clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4538f7d)
#37 0x000000000453a06d 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+++0x453a06d)
#38 0x0000000004541995 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4541995)
#39 0x0000000000cdb0bf clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xcdb0bf)
#40 0x0000000000baa1b4 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xbaa1b4)
#41 0x0000721d05a29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#42 0x0000721d05a29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#43 0x0000000000cd59ae _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xcd59ae)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzkWl9z4ygS_zTKC2WXhP4_5MFx4r1szeykJrndfXMhgWR2JNAByjjz6a8AORaK7SRb8d7e3dQ4ZQtofv3rprsRIClpzQi59OIrL76-QL3acHH5RP9ALMqi-KLg-OnSgwsPLh42VAJFpCqRJIBKUBNGBFIEg-IJIFD1P34QMbedPf_a84e_S952tCEC3Gy7hgsivHABvPhqo1QnvXDhwZUHVzXHBW_UnIvag6sfHlz99tsGRyFm3IuvPZi9vTvMx9Mb3JQ9ooZiUHJMwHfaNKAUSG4AZ2DZIFaDhZREKMoZeBA9-6bnsTIS3_4vu84-oayhjADKFKigBzMP5sBLr2wjAFIhRUsglehLpRtMT7TvaH7vegPgwbATqG4RaImUqCbAg3DBnsBn-1N6EG698AoIonrBgAevPHhlnnjptfnw4g8vHAB46fUE-JiLWwUkIa0EaoMUUJqZmhMJClR-A4qDUnMxC-fJfDzqXulm3LfdS1rsTzPOIjPGhSvBufLgqmke21kn-B-k1D-HfquGFh5cLe4fPLi6VYjRvl3-_vvi6nauaQ4XUabFlJxJZTHpicPFLSZM0YoSccsq7sGF5hMxzp5a3kutuulWUYYXu6f_ZJSzX5G4JmXzC2qJB7MXcodmDybad8LFyBu8xP_6MPPCm5oo20fbUT-gVvTOsHpsom33lZRc4IenziwSsu1IqdeI4qAgAIFeD5p7EHowBRWiDcED2Xefbhb3N0D2RUsVQKDoayBIx4XSgyfuT9WmL-YlbweSX3JNpey196wAYhhQVjY9JkBtyOD62uZKoJJ4cAk6QTrBSyIlwUDyXtjHeiSSkpfUrHPRMyBLQTs1P-oZ_tzz8zvBa4FagETdt4QpOXgF74wXDAFhRnYBYfCMGdrxLmfKLEO4KijbO452MDCr8XckqlkEZjWYcS0XdZ2W3quuV3MJZq3mAsxm2yyZIdnO5BNTaOuF15Qp0oBZxfjskYiCS6LbwewezGZ1Wc4U5025QZR54fVJvLqzZKiTG67ArCp5w8UMU1QzLhUtpZ3DMO089sLlQG94YwkLNGFeuCS88sIb0CEhiQBIAcIw4BWoaENsTzj03AsIF4H-pJpePZCyGlQ9K43r6tgNPJjqKJVaCeFJCZQBrSrvGTZhjGjTAePgqY5w6bX-souuOnL5wN_6u39hUeRhlQHjjmZdySdpv9wJypRxlgfrcdm-k0Df11wqQVBrFtFSB0i7pLIPchkPXvnbAZ6DP5jgT_2iPIR_2RDE-u4Lu6c1QzoI9MxkTgwarmc5B1oNxkELXbR-lKAMLLWL6ZjzSMSThfcPxHCjJ80GJp0-S84U2aoh0vrm8zxFOEyRwgD7MYpgDP1BNRuzt1myTqJZQ1m_ndWstw3lXPJ5YoCbIQ7syJWZJ3lVgk5tBEF4_U3n4ndNYMY7E8RT0FGagFoaLt4LPkoTR3biyoZZWoUAFToov0uyGehITl9IDop3ywwKR2bmygxzkifvk2mGODLzsdelOC2CONIyn_MuYKglsjPrOh8Stc3pv_RtQQRl9eBztrEm6jNidUNZbTvolPwiGdvsb6rJJXhebYNDH6oZRp6sV7YTmhIEM4zJOOffkxbZb1c9bfb1wr0p3L6IXXIfDyl5RwZEo8ca7X1HyiF6jVoWpc6ous0ULZNWWyjYomIq0wRMyuo73tDyacdFcoZAM1CzL5phGAQT7nKc5Ye5u9PZCq8EIfcKMUxZvWfjDdSdJug4sXbahVKCFr0i8ldKvo9IWo5i-OdeoaIhCyHQ01dSeeFyJOeBtF2DFLlDArVEEfGJWp8Lb7SUgvPmtNGmwO5NYv3ES6SM-5zDXNoajrngxFxFHkf_XeY6SfA5ONQUORyGDodJGcdJ-kIFMfp-T9uuIRonEoOxswkZuoGLXew77SivUfbmHgd8dox9xcVXxGpyy6h6aeApqsU52LfkOuxHU_azMD_J_t-P9_8Ai1noxoHYYTFNA4LgaR_eFflfxIjQRaWIGOs3KtbvW9Q0v5JSceFG0nvV7vwphL2JnweJG0-P9aC3melFfvxzZvp4M1iWHTMkEzPAAvt_wgx_F97PwZmmxOEsnXAWIhSf1GE5bFSfubvi-MmDmQ1_58CsITmYswnmOKjQScyrYWc-xTwJX0e83fEYm5_P5NFaEUfT3A3PWYaz8E2aXpOKMvoySt_ZdxX7YP0Wr90Va7es4seqh_GoT7awG6LArrI7Ryg2hIwZg-7uIylwFOJXE9pPgvfdUaIOl1av5bs3BsqjRL8pu7292jgD-YZbh3x3-5KkJSrJq-R_ESOnvWWKCPui54Nrg1cN-qLGPgNlhhGHMjihDMPsdcqGROUwd3S5fzhxr25OzkGc5sUhbrJvyCIET4fGm611raMV7LnIOkfc09o6dEwK-SzO_dNx74F3n8gjaYazlVHXLx36V0_u1KTgeQ6UZjN_oNzZ73Y_c9w35LbtuFAm554pY1o1HR7iKQ-4OF0DrqiQ6n-EDFw4xR1MJsElxdXLfYk5DMym0N097bmKOwvJwewUpFEMqzDJxpiXHJOfCFuYuGcf3WxJ2SsyPNodC34o0gGIg9QpQ6OUoAQ6e-eV0IUBwwegngmkxeCAzF2QSR4ExKXTTnvLpEKsJIcZPa7VWXx5wDlWxD3xirKyKitHkQHyXp_H50IpO6XvWSL0gM9RwCmO_BKTgFSgLIN1i6i75xy_Mt0gsX8hb1-Ous_gEjxyis-jh0XpqAEnasSkQmBH_jJ4MJHi8Ab6tu2agzpN3hxrGUNR7byAx4I-EnHw1CEM3bCRhn6WG2JGcncHtGthuDWtdiXaA1kvXJSoaQpUfltXzA34du7Bh5bBkrctYni6qA_aUKqhH-_07EhzMOJHCcrqIY1YAz8PWK_L7TYI7I8CSVqupek-sOh01g_WSiCq5K55Ig41jV4T9k3G0K67LPYh3jiR5dwM8WDaoLbAyBxA76iC2e7w9WdeHLZHND0yLeJoZIpDB6PDa-ie3aOKNE8OnadNd45TYIPY8fx46mJJWoH_ZxfRpM87JNTcP-kLiUtcmFUpPkqcsR16kTF3bDrBfDJQdzj2fuJE14VT7Ix0-9gCwqjtONSk1AmRn7ybl595IY-T8jMvPlGpjpzQvQzNz37QIapdwJz6vp3HwVn-EjY1WQ6bbjkWR0Gex8eQX4--O4XDgYrhmBX-QjbPUM4aehz-8kliL_xiCG-7CmWH34SVxRAUXk_bH16TaGRj6JFTG_oFQkERAQ36o-e2op25g8ltkhzn77y4Y4Y4MuFUJol8sF7rYWupkFDrkXJvnoVE7izhtJLLEQFW_sfbTAt_nn3cHC4AEYKbu8nmOaiGHQYohxVhL2uC71RtANlSZS8TB6G5DdNLAmaPQHEgCQF0VPbnk1vQ9h4v0WtSD57cp73AlyHOwxxdkMsghXkYpXESXmwuwyjEESIZLrCP_TQt4iTPC1iWOc5QGVcX9BL6MAr8IA-iIIfhPKnyEJYRKaIYx1Xpe5FPWkSbuV4rcy7qC3NF9DIIQj-CFw0qSCPNTXAId8FhR4K5r7rUDeZGI2ez4Ub1vmE6QldLP35oM0Evvr4Ql-Z-atHX0ov8hkol90AUVY25hG6lxNd_9Q3ci140l3_-iu1A4eMl_HcAAAD__973hY4">