ICE on code with constevals

[Fedr]

This program compilation results in ICE:

struct A {       
    consteval A() {}
    A(const A&) = delete;
    consteval void f() {}
};

int main() {
    A{A{}}.f();
}

Demo: https://gcc.godbolt.org/z/rx7js6WrK
Edit: Reduce: https://godbolt.org/z/7rv8b8YxG

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++ -g -o /app/output.s -mllvm --x86-asm-syntax=intel -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics -std=c++20 -Wall -Wextra -pedantic-errors <source>
1.	<eof> parser at end of file
2.	<source>:7:12: parsing function body 'main'
 #0 0x000055f90a339c2f PrintStackTraceSignalHandler(void*) Signals.cpp:0:0
 #1 0x000055f90a337b00 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3537b00)
 #2 0x000055f90a272788 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007fbd7c5fd3c0 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x153c0)
 #4 0x000055f90cdbb6a8 clang::StmtVisitorBase<llvm::make_const_ptr, (anonymous namespace)::VoidExprEvaluator, bool>::Visit(clang::Stmt const*) ExprConstant.cpp:0:0
 #5 0x000055f90cdbca4d clang::StmtVisitorBase<llvm::make_const_ptr, (anonymous namespace)::VoidExprEvaluator, bool>::Visit(clang::Stmt const*) ExprConstant.cpp:0:0
 #6 0x000055f90cd74a94 Evaluate(clang::APValue&, (anonymous namespace)::EvalInfo&, clang::Expr const*) ExprConstant.cpp:0:0
 #7 0x000055f90cd8b326 EvaluateInPlace(clang::APValue&, (anonymous namespace)::EvalInfo&, (anonymous namespace)::LValue const&, clang::Expr const*, bool) ExprConstant.cpp:0:0
 #8 0x000055f90cd92fec clang::Expr::EvaluateAsConstantExpr(clang::Expr::EvalResult&, clang::ASTContext const&, clang::Expr::ConstantExprKind) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x5f92fec)
 #9 0x000055f90c509e19 clang::Sema::PopExpressionEvaluationContext() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x5709e19)
#10 0x000055f90c3b9990 clang::Sema::ActOnFinishFunctionBody(clang::Decl*, clang::Stmt*, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x55b9990)
#11 0x000055f90c1e1827 clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x53e1827)
#12 0x000055f90c136d64 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x5336d64)
#13 0x000055f90c15ffcc clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x535ffcc)
#14 0x000055f90c131df9 clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributesWithRange&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x5331df9)
#15 0x000055f90c132501 clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributesWithRange&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (.part.280) Parser.cpp:0:0
#16 0x000055f90c138429 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributesWithRange&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x5338429)
#17 0x000055f90c139849 clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x5339849)
#18 0x000055f90c12d0a9 clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x532d0a9)
#19 0x000055f90b2bae72 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x44bae72)
#20 0x000055f90acb9fd1 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3eb9fd1)
#21 0x000055f90ac55532 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3e55532)
#22 0x000055f90ad836f3 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3f836f3)
#23 0x000055f907f7c03c cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x117c03c)
#24 0x000055f907f781fd ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#25 0x000055f90aaf4dd5 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#26 0x000055f90a272d73 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3472d73)
#27 0x000055f90aaf6ea8 clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >*, bool*) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3cf6ea8)
#28 0x000055f90aacb90a clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3ccb90a)
#29 0x000055f90aacc44f clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*> >&) const (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3ccc44f)
#30 0x000055f90aad4d45 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*> >&) (/opt/compiler-explorer/clang-trunk/bin/clang+++0x3cd4d45)
#31 0x000055f907e8a232 main (/opt/compiler-explorer/clang-trunk/bin/clang+++0x108a232)
#32 0x00007fbd7c0ad0b3 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b3)
#33 0x000055f907f77d7a _start (/opt/compiler-explorer/clang-trunk/bin/clang+++0x1177d7a)
clang-14: error: clang frontend command failed with exit code 139 (use -v to see invocation)
ASM generation compiler returned: 139

[llvmbot]

@llvm/issue-subscribers-clang-frontend

[llvmbot]

@llvm/issue-subscribers-bug

[Izaron]

Proposed fix at https://reviews.llvm.org/D119095

[llvmbot]

@llvm/issue-subscribers-c-20

[xgupta]

Fixed on trunk.

[Fedr]

If one removes = delete:

struct A {       
    consteval A() {}
    A(const A&);
    consteval void f() {}
};

int main() {
    A{A{}}.f();
}

then Clang trunk still shows an error:

error: call to consteval function 'A::f' is not a constant expression

Online demo: https://gcc.godbolt.org/z/eYTKz6zKh

[AaronBallman]

There's no definition of the copy constructor, so the diagnostic makes sense in that regard. However, it looks like Clang is missing a copy elision during constant evaluation: https://gcc.godbolt.org/z/Yj4bvon3f (note how the non-consteval variant returns 0 instead of 1 -- runtime execution is eliding the copy constructor but constant evaluation is not). I think this is a separate issue, so I've filed: #60286