<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/127911>127911</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            clang::CastExpr::CastConsistency() const: Assertion `!getType()->isBooleanType() && "unheralded conversion to bool"' failed
        </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>
    Compiler Explorer: https://godbolt.org/z/MT6db5cbq

Console:
```console
<source>:7:15: error: use of undeclared identifier 'nullptr'
    7 |   switch (b = nullptr)
      |               ^
clang: /root/llvm-project/clang/lib/AST/Expr.cpp:1949: bool clang::CastExpr::CastConsistency() const: Assertion `!getType()->isBooleanType() && "unheralded conversion to bool"' 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 -fno-verbose-asm -c --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics <source>
1.      <source>:9:9: current parser token ':'
2.      <source>:5:15: parsing function body 'f7'
3.      <source>:5:15: in compound statement ('{}')
4.      <source>:8:3: in compound statement ('{}')
 #0 0x0000000003e9f068 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3e9f068)
 #1 0x0000000003e9cd24 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3e9cd24)
 #2 0x0000000003de9128 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x0000735946a42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x0000735946a969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x0000735946a42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x0000735946a287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x0000735946a2871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #8 0x0000735946a39e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #9 0x00000000076cd2d0 clang::CastExpr::CastConsistency() const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x76cd2d0)
#10 0x00000000076ce14d clang::ImplicitCastExpr::Create(clang::ASTContext const&, clang::QualType, clang::CastKind, clang::Expr*, llvm::SmallVector<clang::CXXBaseSpecifier*, 4u> const*, clang::ExprValueKind, clang::FPOptionsOverride) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x76ce14d)
#11 0x0000000006644791 clang::Sema::ImpCastExprToType(clang::Expr*, clang::QualType, clang::CastKind, clang::ExprValueKind, llvm::SmallVector<clang::CXXBaseSpecifier*, 4u> const*, clang::CheckedConversionKind) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x6644791)
#12 0x0000000006dfd9bf clang::Sema::ActOnCaseExpr(clang::SourceLocation, clang::ActionResult<clang::Expr*, true>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x6dfd9bf)
#13 0x00000000065357c2 clang::Parser::ParseCaseExpression(clang::SourceLocation) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x65357c2)
#14 0x00000000065b0e13 clang::Parser::ParseCaseStatement(clang::Parser::ParsedStmtContext, bool, clang::ActionResult<clang::Expr*, true>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x65b0e13)
#15 0x00000000065a84a3 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+0x65a84a3)
#16 0x00000000065a9b30 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x65a9b30)
#17 0x00000000065aa9f5 clang::Parser::ParseCompoundStatementBody(bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x65aa9f5)
#18 0x00000000065ab0e4 clang::Parser::ParseCompoundStatement(bool, unsigned int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x65ab0e4)
#19 0x00000000065a7ba7 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+0x65a7ba7)
#20 0x00000000065a9b30 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x65a9b30)
#21 0x00000000065ac388 clang::Parser::ParseStatement(clang::SourceLocation*, clang::Parser::ParsedStmtContext) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x65ac388)
#22 0x00000000065aecbd clang::Parser::ParseSwitchStatement(clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x65aecbd)
#23 0x00000000065a86f7 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+0x65a86f7)
#24 0x00000000065a9b30 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x65a9b30)
#25 0x00000000065aa9f5 clang::Parser::ParseCompoundStatementBody(bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x65aa9f5)
#26 0x00000000065ac1fa clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x65ac1fa)
#27 0x00000000064bd653 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x64bd653)
#28 0x00000000064f237d 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+0x64f237d)
#29 0x00000000064b139e clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x64b139e)
#30 0x00000000064b1b59 clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x64b1b59)
#31 0x00000000064b9303 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x64b9303)
#32 0x00000000064ba1fd clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x64ba1fd)
#33 0x00000000064ba6a0 clang::Parser::ParseFirstTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x64ba6a0)
#34 0x00000000064ac663 clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x64ac663)
#35 0x0000000004860688 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4860688)
#36 0x0000000004b274b5 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4b274b5)
#37 0x0000000004aaae6e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4aaae6e)
#38 0x0000000004c15f0e clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4c15f0e)
#39 0x0000000000d6562f cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xd6562f)
#40 0x0000000000d5d0aa ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#41 0x00000000048a6c99 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
#42 0x0000000003de95d4 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3de95d4)
#43 0x00000000048a728f 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
#44 0x000000000486a40d clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x486a40d)
#45 0x000000000486b48e 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+0x486b48e)
#46 0x0000000004873445 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4873445)
#47 0x0000000000d62423 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xd62423)
#48 0x0000000000c2b604 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xc2b604)
#49 0x0000735946a29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#50 0x0000735946a29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#51 0x0000000000d5cb55 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xd5cb55)
clang: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134
```
Code:
```c
#ifndef __cplusplus
#define bool _Bool
#endif

void f7(void) {
  bool b;
 switch (b = nullptr)
  {
  case 3:
    break;
  }
}
```
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJzsW19v27iy_zTMC-FAov5ZD3lQnHhv93bR3iZY7JtBkSObN7KoJak0OZ_-gJRs_YnjJrvqogenQV3YEmf4m98Mh0OJpFqLbQVwhaJrFN1c0MbspLrKRcwucsmfr1ZyX4sSFL59qkupQKEgwztjao2CDJE1Iuut5LkszaVUW0TW_0Jk_dt9zPOI5X8iL0NetpKVliVYAS9Dsdf-Y91VL0PBSstGMUDBLQqyBAWZH9l-QCnpOmw0YFngpuLASqqAY8GhMqIQoDAiSdWUZW0UIgnyMowxTjBKVhhj_VUYtsOILHOMght8bJh2DXHXcPiHolvkZayk1dZ2jshaSWkQWZfl435RK_n_wOzPtgVZlyJHZJ3d3SOyvn2q1SWra2tDGqZWPpeyxAdtKMhWVBvbrP9lCRLaQMWeEVkikmJLjrHCmdagjJAVtqwRfwvm_rmGttkCBbdCX0tZAq36yxiRGJEYI0KaageKlhy4VfkISltVRjpQiBBEElxQUQK_RF72-eNtdneLdZPvhcEU580WK6ilMlZk4nVhdk1-yeS-I-YlP0LrBjQia0wrjkXFyoYDNjvATFG9wzllD0ZRBoiscK2gVpKB1sBxFw5k5SSp1pIJaoBj1VRYMyVqY_HeGcoeMG_2dRtb3iXy0s9KbhXdY6q2zR4qozsfytr5rIvnBRziufPjgh6Y1gujmuoBkXUuqsNtvNjyr1QVixAvtnghrUZa11ZvY-rGXGq8KCq5eASVSw0Lqvd4wfBisWVsYaQs2Y6KCgU3Z5HYxrqitd5JgxcFk6VUCy7otpLaCNb14dgbXR6NIC_zLQ-TUZV2H8wapaAyuKZKg8JGPkBlx5DzrB0_5IR0dByTVkxUW1w0FXNxadOElS-SVjw4Ky4qbA2XTcWxNtSAdRF2cZug5BolN_aLG57hCUVLFGTBO_VgRAIPe0_e4S-AtPDiJXZR6wahftbtl89KVMaF1X0bmMu-kaJfN1IbBXTvBtgKi8q0w235t-MLkWvvqQPWw_YnsBkn4SnYK5sAmvpTdSe2FS0RWTaVS-wcl9IqnxekhdGDJCOQHFKfLPHKxugXYPIR1HOL6n9oxUvb17LjbdRmJSsDT6bLnZ77tPqDTn8SRGkY05BExOvMaTPv0zLexOGiFFXztNhWTXuDXWp5GTvITqQHHI4VpnFaMFybnQLKNw-iLN-n3cn32qMp3DCJ8VY7Ct4LO0ziXnE8VkyWSRFgmtvs_C61TrBXm7xQ6-fvVujnvcLlWGGQQhq_T6ET6RWmwwBLYsYJ9_7ShDrfIOhQtBjtQPUmGMEP-RDjh31dCibMBKsCamyWGbTM7u67sdBVAW2uGbT4v4aW7Wy_mtLwv6Lik8uuN5LZq33muNvTsvwdmLH11Wqo5I8_rqmGuxqYq646ybBBwe0BT3aih99p2cCJ3tefP9WOyk-PoJTgMGsu6oju3TBKmHEchknqD-HcwZ4eHXLwxb3saqfTrP0t5ke8fCf-VztgD8BXxwKv7W9Gnjsme55HOT_mBU_z4jTPGTOfqhXV0DI65PjOTewfJaO294lRmasuvoBuSjOmaOAaoxpXGMxqa2tNb2swsjUKooSRIdLPrpAafD9YC1o7u87ZPCfwFloPPBwDzz3wg28CvzsUU2PcL9ryO7M3XaKyrmgXFD-IC1tbeyaiMRN0GdLzTBxZ-KRu3JLTuSsrDKjMGCXyxtiVzfINI9ry1NkakMaZOk3o3yT3TABNk0ErPwR5srdpi1nZd_z27McT9tM88P4C-z8K3fNSZcnoqUomVNG0iM4P2W4RdKTsWnJb87TDcV6oFkwPdTmBmnsQvg_qEeYKH5crcy-pOmA97HQCO8lp8jMVfL9UYPk9sk-8n6ngjamA-BOqWLBcvo2q8xXHySh5nYJ5TbRG9CaSiYnAcn7eRPc49-2GzgvewuvBB9OaIi5-JpLvWVPExSCRhD8TyVsTybT4_XFrCjKtFJlf0LNQ191T6CnUgYz19huy3h2Tdl0_e9haE3oDx_VdmPM4Or8QORh4A4WohHmxnvzcPo4_hLRUbwnNe9jXJTXwoSrkaw-ZhlIfqYF-hH8U3UOIOYlqqeiJGleXYUGC5PzUYBn4RcmmfpWfuxrYSzt75k4P1jfmvlf5fdn-PRPyWqovtNrCh0p8B84dqz3n6SQ4_SCFb3L-SQ1C9ENlQLUvIP7-9PGixVk_ZoyB1oPnZvNGp-XiyNT4dZK9m0fpN5nqppwRYa-O6dn5mkbZ9-Yrj9KeL3_CVxp459Pe7VMbSOOp-h_gaF4WrJ09C2TCAvWL8zntXtYf4RHKdgobmv-ppn828NlMCpVjEvwCxckypX8u-5vkTQkf9rVUxs2es899rYG9-cHU_JieL9nWQmnzH89BTPtaLBiXrSFlcfxyILidJMsp4taOwwOT-WuxFkwPdVQ2hsvYi8frz5Xk8AtU7UPew2NdYI2B7tJhL8pMADsIPcBRsRjmJAnzUV27VnZCr_gJhLNja3vvsY3qvJBSCjGMyWt7-1BpQysGp_l73ZiZ47RD2OMflV8h86PCg_GrLYe0N-PxWM4sz5k5c4rtkPW4RyWMx-MoJgVmzN_sqRgv9jKl6LNLESu2o6p_t2ZTxgqPr5EVfpSCzw2_xXdEH3pj9BH3KMUHqlf-vRvzpxesH_Z1edKUePzi0ep4-Xo5xVyJR1CT3RcWkz9OAzRmaerIGCg97AXaKMenu9sOsXbXDgoyRssyp-xhU1TjdN123IXLyl_J_Z5WfDpaT_pNm66ddK-YqSVgQI5Rotp2k0Dr1KPAZsOenny__ZFTLdhGu-YdhaPG9sLGKCqMPtyeqKNlacO_fWzQ3bdNsj5TZ8NdfchttSrpPufUbVM6UEWWh-06v8r8hDNebLWJ-HA_0KkNNe2dL011Rwson0dcnvfbrJuGWqx9qAeTsErIcvQC-b8uLCzXlzVV5tJ73f_hZE6mocdfZc35i76Y-w5UjhL1RNA2eO3BwJmm2ahImX3TTWdwH0TTEiUPl_BeOn6VuX6di19l_lHo8U6cc_n36PuaCut29zrr7fR1AfKdSbQ09SSOy6hlEoRh9Brgm8H3UQlwYu5_jfx_kMRZq09HTE9bMqk0SEi6Sv5Qaxxgu8SRvdiC9dpMPGN1YTH1iEc1ncdIHnshtljn67JV2neZTvYWpjx959ZNJ3JUGHlThRB6eLOxMhttqDKbgUFv7gLCQRf-pAhjeRThVvmMvnFq204Pcd0fd3BXcNGV_Jh1Ed5u1MdfhdlheBI2bDhgPwgtrkYDXjxiI7EGwGJQkKfuCEZ3jEOBaVQFdoBZyeGBDNeMvzim0dIiiopDgTcbVpeNtp_2OodCVNCecdhc25TlLkPFRdGe_nBVRWGLnLaETjFKrt3pCyeUo8D9-sZJjYMMoxpw0GLEGONcAX3oVGCU3Ng-2_8PBlzwq4CnQUov4MpPQls4Rcv0YneVennMAur5oUepD0kEAV-GQcHSMKEFSS7EFfFI5BE_JcRPw_QyIOAX1F9GHEjocw-FHuypKC_tqL6Uanvhjjxc-SRJff-ipDmU2h2tIaTzPUHRzYW6cicl8marUeiVQhvdqzDClHA1XET9kOdFLhpVXv31IyEdRY9X5N8BAAD__7xVRTg">