<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/150705>150705</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [clang] Assertion for invalid program in constant evaluation for virtual function call via member pointer into sibling class.
        </td>
    </tr>

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

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

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

<pre>
    Current clang trunk fails crashes on the following program with an assertion (see https://godbolt.org/z/sxbeK4qdc):
```cpp
struct A { };
struct B : A { };
struct C : A {
    constexpr virtual void foo() {}
};

consteval void test() {
    auto p = &C::foo;
    auto q = static_cast<void (A::*)()>(p);
    B b;
    A& a = b;
    (a.*q)();
}

int main() { test(); }
```

```
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-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 -std=c++23 -pedantic-errors <source>
1.      <eof> parser at end of file
2.      <source>:15:12: parsing function body 'main'
 #0 0x0000000003ca4b28 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3ca4b28)
 #1 0x0000000003ca24fc llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3ca24fc)
 #2 0x0000000003bf2828 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x000077be12642520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x0000000007442bb8 CastToDerivedClass((anonymous namespace)::EvalInfo&, clang::Expr const*, (anonymous namespace)::LValue&, clang::RecordDecl const*, unsigned int) ExprConstant.cpp:0:0
 #5 0x000000000744f1c6 HandleVirtualDispatch((anonymous namespace)::EvalInfo&, clang::Expr const*, (anonymous namespace)::LValue&, clang::CXXMethodDecl const*, llvm::SmallVectorImpl<clang::QualType>&) ExprConstant.cpp:0:0
 #6 0x000000000749caa2 (anonymous namespace)::VoidExprEvaluator::VisitCallExpr(clang::CallExpr const*) ExprConstant.cpp:0:0
 #7 0x00000000074c4d79 clang::StmtVisitorBase<llvm::make_const_ptr, (anonymous namespace)::VoidExprEvaluator, bool>::Visit(clang::Stmt const*) ExprConstant.cpp:0:0
 #8 0x000000000745744d Evaluate(clang::APValue&, (anonymous namespace)::EvalInfo&, clang::Expr const*) ExprConstant.cpp:0:0
 #9 0x000000000745e9d8 EvaluateIgnoredValue((anonymous namespace)::EvalInfo&, clang::Expr const*) ExprConstant.cpp:0:0
#10 0x00000000074682c0 EvaluateStmt((anonymous namespace)::StmtResult&, (anonymous namespace)::EvalInfo&, clang::Stmt const*, clang::SwitchCase const*) (.part.0) ExprConstant.cpp:0:0
#11 0x0000000007467318 EvaluateStmt((anonymous namespace)::StmtResult&, (anonymous namespace)::EvalInfo&, clang::Stmt const*, clang::SwitchCase const*) (.part.0) ExprConstant.cpp:0:0
#12 0x000000000746bec8 HandleFunctionCall(clang::SourceLocation, clang::FunctionDecl const*, (anonymous namespace)::LValue const*, clang::Expr const*, llvm::ArrayRef<clang::Expr const*>, (anonymous namespace)::CallRef, clang::Stmt const*, (anonymous namespace)::EvalInfo&, clang::APValue&, (anonymous namespace)::LValue const*) (.isra.0) ExprConstant.cpp:0:0
#13 0x000000000749c8c4 (anonymous namespace)::VoidExprEvaluator::VisitCallExpr(clang::CallExpr const*) ExprConstant.cpp:0:0
#14 0x00000000074c4ccc clang::StmtVisitorBase<llvm::make_const_ptr, (anonymous namespace)::VoidExprEvaluator, bool>::Visit(clang::Stmt const*) ExprConstant.cpp:0:0
#15 0x00000000074c52fc clang::StmtVisitorBase<llvm::make_const_ptr, (anonymous namespace)::VoidExprEvaluator, bool>::Visit(clang::Stmt const*) ExprConstant.cpp:0:0
#16 0x000000000745744d Evaluate(clang::APValue&, (anonymous namespace)::EvalInfo&, clang::Expr const*) ExprConstant.cpp:0:0
#17 0x000000000746e6f6 EvaluateInPlace(clang::APValue&, (anonymous namespace)::EvalInfo&, (anonymous namespace)::LValue const&, clang::Expr const*, bool) (.constprop.0) ExprConstant.cpp:0:0
#18 0x00000000074c3876 clang::Expr::EvaluateAsConstantExpr(clang::Expr::EvalResult&, clang::ASTContext const&, clang::Expr::ConstantExprKind) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x74c3876)
#19 0x00000000067b7380 clang::Sema::PopExpressionEvaluationContext() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x67b7380)
#20 0x0000000006618e42 clang::Sema::ActOnFinishFunctionBody(clang::Decl*, clang::Stmt*, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x6618e42)
#21 0x0000000006386fdf clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x6386fdf)
#22 0x000000000625e9b8 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x625e9b8)
#23 0x00000000062aae6f clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x62aae6f)
#24 0x000000000625779f clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x625779f)
#25 0x0000000006258587 clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x6258587)
#26 0x000000000626117f clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x626117f)
#27 0x0000000006262990 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x6262990)
#28 0x000000000625110a clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x625110a)
#29 0x00000000045eee5d clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x45eee5d)
#30 0x00000000048f82ba clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x48f82ba)
#31 0x000000000487359b clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x487359b)
#32 0x00000000049ec3f3 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x49ec3f3)
#33 0x0000000000dbaf25 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xdbaf25)
#34 0x0000000000db2e7d ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#35 0x0000000004660aa9 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
#36 0x0000000003bf2c43 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3bf2c43)
#37 0x0000000004660cc9 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
#38 0x000000000462416d clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x462416d)
#39 0x0000000004625121 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x4625121)
#40 0x00000000046318bc clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x46318bc)
#41 0x0000000000db7741 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0xdb7741)
#42 0x0000000000c67bc4 main (/opt/compiler-explorer/clang-trunk/bin/clang+++0xc67bc4)
#43 0x000077be12629d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#44 0x000077be12629e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#45 0x0000000000db2915 _start (/opt/compiler-explorer/clang-trunk/bin/clang+++0xdb2915)
clang++: error: clang frontend command failed with exit code 139 (use -v to see invocation)
Compiler returned: 139
```

The program should be ill-formed, because the most derived object `b` does not contain the member `foo` which the member pointer `a` references, causing the call to have undefined behavior.
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJzkWl1z47aS_TXwC0oqEqRI6sEPtGxnJ5nUzI5dU3lTgWBTQoYCOACosffXbwGgxA_5M1Gyyd5bN4lMAo1zTjcaDQJUa74RAJdocYUW1xe0NVupLr8BF1XdwkUhy8fLVasUCINZTcUGG9WKb7iivNaYKaq3oLEU2GwBV7Ku5Q8uNrhRcqPoDv_gZoupwFRrUIZLgRHJNADeGtNoFOWI3CJyu5FlIWszl2qDyO3_IHKrHwr4Jf5eMkSWtlmQoyTw_2dNg4JcG9Uyg3OM0iuM0msUXfVPrzCK8mferfp3KMgxxphJoQ08NArvuTItrfFe8hJXUiKSIbJ0TdNri-FgCwW577U_tDagzaC5t0xbI3GDUXSNEUlWlkiUW7vRqMV310IbajhbM6oNilbOKCJZ7jshklsl3AAoukEka9yvg50rXPR_5IgkmDqjg6eIZHSOSP59YOiqI-UYcWHwjnLR0xiwQpGXcuAI32v45-ePN_ndDdZtseMGU1y0G6ygkcpgI6c-52bbFnMmd4jc1vX-8J9Zo-TvwAwit1zrFjQit5iKEnPB6rYEF2ku8HBB2TejKANEVrhR0CjJQGsosZat8o9tT6q1ZJwaKLFqBdZM8cbMUZDfGcq-4bLdNT7GgjkKlp-72KVq0-5AGAsZI3IrG4uJyV3Da1AzeGhqqUDZZ3ZizNzEQOS2sAr6Z4hcIXKFZ5vyB1XVLMazDZ5Ja4w2jTXZmqY1c41nO0sdz2YPWTKjejfTj8LQBxRdc2GgxrNKyNkeVCE12Pd4dodnsw1jMyNlzbbWa9H1iyBtYy1oo7fS4FnFZC3VrOR0I6Q2nGk_hhN2_FibEkXXzHMhEZ41UFJhOJuBUlJpjKJVp3d0g4I8tCKiaAWyQtENbqjSoDA1GESJZYUrXgMKctI167tGebiw_yJWcNvNZpKqFcwlDpuKMCKpj9DUBjUiUYCDh-Dwv4jRuCAZdtHkpo1-1P7HZ8WFce6-9wGT9Y0U_bGW2iigO0QSGzRcGDcDbOT_cb8jchU8dJjsDPKIwwliElfsKcSrGqhom0_ijm8ErRHJWuGSdYlraYc4Gz6LoMdHRviKimQkwysbFl-AyT2oRw_ov6goaztM1qk1arOSwsCDmdtkHeWB-8fbjzr7aVpASJKYLEjQMal5gcjtQ5ask3hWc9E-zDai9S_YXMt54iC7Lj3geAg4jWNSFBleUW3u5TUovodyVVOt3RAZFVI87mSrsaA70I2LhaVX_GZP6w-ikl0QeKX8G7s4uITv8vAKv2Lp41dat3Bqx6qjymtg9cja0bGdkna4lX1PxVMKLiaEq5Al2Lvjq1_ArrluqGHbfwLn1W-__QpmK09p90F_t6N1_RWYkerDrqlRtBoY-O-W1vePjUsR1vqr-iRjfZaMUvIa-q-Sl9as1aOlRqruMdfcrGhd23eIZENe3dMBpVeRpWNkLC7T5VCrO7MzbkiprqgGFK16jXb0G6zdWOvGqDc45JQSWeFCytrn2gO7MSuL4D2MsjGjRRrHJe5GhLHp_PMwQs4Vl68iXE4QwrLMjgg_bIRUUHbAzjZZXgRl14BgDCrJCAuOoKwPXgdjW30B3dbmzyo68fn43Q9u2HZFNYzoIZLNG6rMPHgD2XBCNo3C7P8tWTIhWwDLuuR825UyNnNMZp2rgT5KRu37CapDt5P8-aaE_BzXk_TeZ5pcKfr4BapxGh53sLn4VQSWqLXzigf-sC_flVFO5PCO5VrRNzk2mq4qGYv_71cViyyeriqMsX_vqmIZTSoctiDVv5xR8o9eJy3CSW2SQFIl_TopPtd-23QmoO-arK-Wps5b3YR2zxslmzfN6kn9wqIsTaZD9QSsFLk-mDudvePWowVrqNvdfbc9eolglw8GY_3CRWkpuU5n2fx1hP1eysoxKpaStEijLBhNPNjRbkMtG4sJtOZSdNrYtc0TO3xCOgPGDsURIxnVTkkSZhCTpzHmzHwSt1xwvT0soleyfBz7zC6rT5QCriyZBtefJ-Ph9mRGtVESZUlVVkMcn93Xk8HvA5E7Qw3sQJi3MjqxdMdkA92O6izcPPqe26gUSsgClkX2Jm7XUHHBfSmUTTpwsbH8qPKZejpzTmyW97BrapfCKvncfBv2-kgN-J65MeojH1YLf14jr0KvUTTWiFJIXva_Jf-Tkm3zrDR3DbBTir1oxyl6KoGjzIvWgH6vtE9U2pOi9qWAvJXqCxUb-CD4eeV2gvZyx5OQTNPl63J_UoPA_CAMKP897v3qvdriRRfmjIHW9h2vuNXgbDFpZehFWkxEyhZZ-qpINra4FCOtnp3EZ5dqGlt_nVRWjF6qZCxVEobpy_F08-DDZyDZ3yPPuQRwFHsB0okAZLkMXhTgXjYfYQ-1X6SGzD819HsLn40a7zuPCc_tSG-eyDPH9f5XWbY1fNg1Uhm3Pp5zdfPceubZZJaEYUBPmOd395N9gwXrKfi64sz1hcfRoxwVdPECABbl6OusLOEnELmbsofiE1hroHt0vkKuG_2IbXx2E2dVRoqRgrfKrlSifALcOWH5gXtY4RhWGi2WxVgyP9AHV5kzeFq153mcLyY7cD30UcUVL4FFVTTeVziQPYP9cXXOXmJ4vgTSgeohjwqgoCxoRRaYsXDdnUQ__VlqS0--RY2fkZU7lj8jcg-tBx5PgBNIS3wQeBXeu1mdvXjGccIiGX-IszZOd4pLXCq-B3W6mx2fDMVJElC69NcTeqOHA9W1clIe7hl09wpcE0bruqDs27oS41zsB-6CZBWu5G5HRTmdmU-6zJ0i22eysaPTevTR5s4oLjZdhvf-PHZYr9nDQxj6PwqqOVtr17yTcNTYPlgbRbnRh9cTc7SubdBLNXhvmwz2evlxl-27IJLWdFeUFJF0eAXjcA77syyecEYyPUhlcTTww1PHpf7Nl1bc0Qrqx5GWL_vtXKfBHmYf5ek0ohgbnVj9x0XE5DTgaddnY9VIHCbls6o5V9GTJe4g5SgzTzraBs_taV9omo8qkHN-UOq49vGznCixCEn4XiV-loV-XoafZWE36SMZXsq6R7c3lFuPuzP3tyvXxcZfp59V6KhfPK6RkijMCvYc1uvB79FK_8QS_5zuf6N-ZyoovCa9YuFkXU7TuIu4Q0lxQOwyRX5y_PXcqnueIsLC6cGOCraAJWnBYncH7yyjeXv9aJOrN2RZLt959cZ16Q3GU4MQB3i9tn3W2lBl1gMubx4C4sEQi2mZtQwX2Bs_k0esRT_e8F2UY3e9zf5wz3HVlfGYdTFdUV5D6e-4wgO30VICDiMXKq0GPNtjI7EGwHxQaduRDhU2VmBaJcBOKdvz9Hrl_RaOt2n1VrZ1iQvAvK5nlVQ7KF0eAkbteGYLeCe1waW_94Rl8Tswg1ESFCgJcClBYyFdWBvrGNcBdgUo26aS0rb6seVsO3zVSC6Mb0JtAwUVKBAMtJtGtHUX9dy1TFrX7qYn3QNuRQkVF2ABb-meSzW_KC-jchkt6QVchukiitMsisOL7eWiTNiSQpTFWQUstVsyEmZBGQGESbAMLvglCcgiSMmChOEyCOdxRiJG0iqs6JIuyiWKA9hRXs_tRJ5Ltblwt0cvw0WQBouLmhZQa3fNmZDOzwQtri_Upbt0WrQbjeKg5tro3oThpnZ3o32PxTXOjxeZK6msW2nNy6ODuPAZgwqD4Xgm4poerhYf7zM6rfacTlXmwsYML2orKqup1vOLVtWXf_z2bCfB_pL8bwAAAP__S5oNCQ">