<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/97005>97005</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Clang crashed in ASTContext::getCommonSugaredType
        </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>
          spavloff
      </td>
    </tr>
</table>

<pre>
    Clang ToT version is used:
```
$ clang --version
clang version 19.0.0git (https://github.com/llvm/llvm-project.git 5bbec8f4b6a26e8b4a4209d90a2ad0a0d2416a55)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /ext/sdc/arbeit/space1/build/bin
Build config: +assertions 
```

The source code is:
```
$ cat reduce.cpp
bool a;
constexpr const unsigned char c[] = { 5 };
constexpr const unsigned char d[1] = { 0 };
auto b = (a ? d : c);
```

Running the compiler results in a crash:
```
$ clang -fsyntax-only reduce.cpp 
clang: /export/serge/llvm/space1/llvm-project/clang/lib/AST/ASTContext.cpp:13501: clang::QualType clang::ASTContext::getCommonSugaredType(clang::QualType, clang::QualType, bool): Assertion `QX == QY' 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: clang -fsyntax-only reduce.cpp
1.      reduce.cpp:4:20: current parser token ')'
Stack dump without symbol names (ensure you have llvm-symbolizer in your PATH or set the environment var `LLVM_SYMBOLIZER_PATH` to point to it):
0  clang 0x0000000002070b28 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) + 40
1  clang     0x000000000206e55e llvm::sys::RunSignalHandlers() + 238
2  clang     0x0000000001fe5727
3  libc.so.6 0x00007f9621462520
4  libc.so.6 0x00007f96214b69fc pthread_kill + 300
5 libc.so.6 0x00007f9621462476 raise + 22
6  libc.so.6 0x00007f96214487f3 abort + 211
7  libc.so.6 0x00007f962144871b
8  libc.so.6 0x00007f9621459e96
9  clang     0x000000000529813c clang::ASTContext::getCommonSugaredType(clang::QualType, clang::QualType, bool) + 8332
10 clang     0x00000000049ad0d4 clang::Sema::CXXCheckConditionalOperands(clang::ActionResult<clang::Expr*, true>&, clang::ActionResult<clang::Expr*, true>&, clang::ActionResult<clang::Expr*, true>&, clang::ExprValueKind&, clang::ExprObjectKind&, clang::SourceLocation) + 1412
11 clang 0x000000000483ac6f clang::Sema::ActOnConditionalOp(clang::SourceLocation, clang::SourceLocation, clang::Expr*, clang::Expr*, clang::Expr*) + 367
12 clang     0x00000000044111e6 clang::Parser::ParseRHSOfBinaryExpression(clang::ActionResult<clang::Expr*, true>, clang::prec::Level) + 4742
13 clang     0x0000000004419b5d clang::Parser::ParseParenExpression(clang::Parser::ParenParseOption&, bool, bool, clang::OpaquePtr<clang::QualType>&, clang::SourceLocation&) + 3021
14 clang     0x0000000004416e76 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, bool&, clang::Parser::TypeCastState, bool, bool*) + 11270
15 clang 0x0000000004411761 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, clang::Parser::TypeCastState, bool, bool*) + 33
16 clang 0x000000000440ff04 clang::Parser::ParseAssignmentExpression(clang::Parser::TypeCastState) + 196
17 clang     0x00000000043d2156 clang::Parser::ParseDeclarationAfterDeclaratorAndAttributes(clang::Declarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::ForRangeInit*) + 3670
18 clang     0x00000000043cf299 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) + 3433
19 clang     0x00000000043a6285 clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) + 1365
20 clang     0x00000000043a5ab4 clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) + 596
21 clang     0x00000000043a4abb clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) + 3659
22 clang 0x00000000043a2229 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) + 2217
23 clang     0x000000000439d4e5 clang::ParseAST(clang::Sema&, bool, bool) + 581
24 clang 0x0000000002b3be76 clang::FrontendAction::Execute() + 262
25 clang 0x0000000002aa0934 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) + 1092
26 clang     0x0000000002c0dd07 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) + 535
27 clang 0x0000000000b39f37 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) + 4967
28 clang     0x0000000000b36993
29 clang 0x00000000028cce69
30 clang     0x0000000001fe5469 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) + 137
31 clang     0x00000000028cc83a clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const + 266
32 clang     0x00000000028831df clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const + 463
33 clang 0x000000000288375a clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const + 154
34 clang     0x00000000028a7b17 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) + 743
35 clang     0x0000000000b35865 clang_main(int, char**, llvm::ToolContext const&) + 5461
36 clang     0x0000000000b46347 main + 87
37 libc.so.6 0x00007f9621449d90
38 libc.so.6 0x00007f9621449e40 __libc_start_main + 128
39 clang     0x0000000000b33f85 _start + 37
clang: error: clang frontend command failed with exit code 134 (use -v to see invocation)
clang version 19.0.0git (https://github.com/llvm/llvm-project.git 5bbec8f4b6a26e8b4a4209d90a2ad0a0d2416a55)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /ext/sdc/arbeit/space1/build/bin
Build config: +assertions
clang: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: /tmp/reduce-159e8c.cpp
clang: note: diagnostic msg: /tmp/reduce-159e8c.sh
clang: note: diagnostic msg: 

********************
```

The crash is triggered here:
```
clang::QualType clang::ASTContext::getCommonSugaredType(clang::QualType, clang::QualType, bool): Assertion `QX == QY' failed.
```

It can also be obverved online: https://godbolt.org/z/GGnfzbPv7.

</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzsWl9z47gN_zTKCycZidTfhzwoTryba67JJe71ri8eSoJsdmVSJSlfcp--Q5GyZcfy5v50p51pxhNLJEAC-AEgSJoqxVYc4NqLbrzo9oJ2ei3ktWrpthF1fVGI6u161lC-QguxQFuQigmOmEKdgsojueffen7uxb772FccorJnurx0LLbDNg6jBNmVf-WvmEYeTtdat8oMiOcenq-YXnfFVSk2Hp43zXb4umyl-CeU-spwRUUBZVqHRUxxDGkR0hD7WZX5FNPKp36FwyCmUeThzE6_oHIF2iM5ek3jZRxedvwLF7_wy4bx7vVyxTtHt5ZAK7QRFTSGuhWKvdque640bRqobpk0XR6ew6v28FxVpYfnVBbA-teWlhB4eF50rKnMN3M2uDENqBS8Zis7wg1VCqRmgit02p5OKkBKdLIEVIoKEFNn7U81klB1JVyVbWvbCyEaRD1y49AQXGl4bSXqn1DHe2eoULmmEpXWJZBHbpGX3KAIecntB3krL7oJxsz-ATPttECF7cQpRR6ZowoZY5QGq4HspBWeO84ZXyG9NmbYtKwBiSSortEKMY4oKiVV6w-4Zq3euKavl4I3byNToZGr7hBuhexRBbmCvUfuQB67pofnlhfPG1Z4eJ6_LOz_meAaXnWPB8kDEvlBr7ObySP5Dx1tFm8tjNv2jPZ9BXomNhvBX7oVlVAZeg-nJ0bx8OzU4KbZeEJv6hzlg_MhL_Z_-MmgYoD54WcPJ6imrIHqyprk6eEuf7lDqis2TCOKim6FJBjTIC3QbwtgD8-ZUh0oD88R5RVivGy6CiyuBkFU0PKLlrTsBW4ltFKUoBRULgpMs-GkSomSUQ0Vkh1HqpSs1U7kF03LL6jqNu3OIfwrz8-epFhJukFUrroNcK12QEz6heUODPeokeShR3Ls9_ydlMA1aqlUIJEWX4AjDyfG0Dg5Fgj9wvRadBqpt00hGsTpBpSJB-Cqk4DeRIfWdAuoN5slYr-CNE7-JjqJnvLFZyQkUqB7qwHfMim4UQdtqTRwPjz8-P3y5efvbx4f7v9x97w0LF7sG7hawXiPm0lX2d46yJnBf_WHP-wnfoHTXhDrSupN2YcnybjudVpYpNI9kaS_LIXSEujGw7FBi3Ezl8l4KHTxGAzzmb-DOWOIIjg153PHX9iK0-Yz5VUDUnk4HYbFJLXj4olxgxqiZACDINSworxS4ip2REmdxTgIYxxhJ2E4SVTEWV2iVverxfILa5peBuI7zmh69DCJkaRMgZUaW4Z4cqowTWqCaGFirecIAsuSnGMJCkuUThJFGWSxJcomLBbhLA1I-a1SUq9eSogzSeCflirMaOVX4XiwF9hQ-zT76afZGsovM8ErZlIbbR5bkJRX6lCsvDS9z_3q4ZHZqOfutZUezo1gWnbgkTvnw_8l3IbmR9p08BfGq9Pdj4VJtKf7X_oM-iBKaoQYzB6EwWD24H0aCFNCy7g-bfK81I_8wN6Hlj6e8Kw071Rx1vh4q9WHxC7QAzzhRWEQBBCPh3jqk_fo-fnzy2N9wziVb2Z4UH05-wfc6EDiVkJpnx5gC7sACJNwQIJMip4VUXVW9CcqgU8JfUQNvG94bC0E8T4k998j7seW_quDJy0P9d0F9CmfPYY53uHkY5fOgnBS2xiS80DNqNIfUdbQ9e82NI7VPJZ6zGpUM-wvmmp4z7pzvCDAybDARSciKQyCJA7-s9r8QRUIcfLHp-T369oPz8qf9ztLU4x8RIsjqZwVh6UpSCa8glQ4iM57xS2UDZW9x-W1Bjm8C5nzKtdasqLTcLQu7InO-0P_XC1g0zZUwz2vhd0OneeaC_lM-Qruuam9xtlq8Jl0St-yxln2VX0_SdG1743N-Mr0vrRQvhdwr_KwtJ9Q4MBgv80wX08Hx8n8IyYLd26aTZmMxjiNvmqyRznveJ_Gb6G-5xokp80Jf_26Bb5KcRaGvDR7HNPHagZyFwokjlxhO1UQERrR4nxMjmLhQF_GmT4dnn-2uscYT6gbDZGPg0ltQ1oUZ7W9e7UojrT-NhoO4Ry5YyeMT6RQQjHG50N5Idq-KDCDH0o-sfruYv8Z6tMr8K5e-15UXQP3G7N7d0l3txxjHLi6CU8VHySrQngfVf1RR3o84aliwuGcunV_dyoz3gIWpDha8-fS5CZe2YJrKLGg7Iz8-01g7GonfGLtxZT6GTmIk5k7RurP9ngJB-O6qQ60OhJjb7nAz4ap44l9belXlZ8cFq39RHsptruUmJ6Tcu9qERmSQ_JeYb8gWU0SVJbBckMZP9ij51LSt95bZvbQz65e-VCoHrThGdoKVo0mDrOhwsYTS5ZfkDjLXJIe_P3AIGlZQuwihUwkN7NrD-NsdBowk1Stn6EUW5BvB5vR546_0BqatwNFa5ftlrJX1uiBrMv0qg5ZdjgYmEg7RtiU0DF6lWTbXS02C8w-mPLq2DVPWlxpRydau2nyyGxP-KIl4ysXyRaOHcNyWb6-BoF9Kahi5VL15A7HA2LTsNSSMq2G7qPhaNMYlxNy1G9I8qO60B712hBzCZpM7KxwmpKgqict1TszfRfFg_kOPP-I0RBMlVlnSPODPDRWJoydfxJyyj9TkkTTkE8o8p0o1LQW34nigSl9oMUI-Q1tmh-h1ELeb9pm7CktZQak_iDt44o7OCfUD6LQqT-x-cIpTYogmZrudvR8kMtOJLEp031DE9hQT8IB82gycUVp7DqHxDlM2odY7gJkL_VCiMblohG0LkeHsVvryMTS4BdhTMIEmbnsKdiQjZLJM76sytyegaTTRBD6aLk03UulqdTL3RQBduelZKJ-9gtC6jRCltEWNsnRDQlIKeT-AL12qyMqHQj2EqE_70bwyrS9vgpIaDJwpwBdbpEWSAEgNlr8sv_fGX7ozvAIDS60qWBQxeiKC6VZiTbKcrkbsD_wGV3EudugfLHIZ5_R4vMdmj8-PDz-_f6vn9D8_uHuBS0e--abv31Cz3dPj88Lb7hleDp1m5MqEyuTNzo7AgmoX66gQlTvhvyI_niuN62H5_b-5jKIMkjL_d3O7x9CrX8rCH8WFFMXxfYKjSmkJVutQEKF1iDBm7gW_Z-5gzyp8L1GJeWINkqgApAotiC3UCHBG8Z7HI4yhagK0egrIVcenv_q4fmnT7z-tXjaJm6ai-qaVBnJ6AVcB0mQRRGOsvRifY39LK79Oo6DOMoqXMRBXaUUJ5DiIkwxvWDX2MehH-PUj3AWpVcY09CPk6ROU5_ENPVCHzaUNVcmNxkRLvqL0Oss8f3ooqEFNKr_OQbG1nAYe3hm3gykl4JfbmljqnDsRbcX8rpPcUW3Ul7oN0xptR9YM92A-_lGzw0VYhx9BM2LTjbXv_9K1yqzvcb_DgAA__-XuDum">