[clang] (Presumably) CTAD and consteval constructors in more than one class cause segfault

[cjdb]

Clang and system details

Clang installed from https://apt.llvm.org.

$ clang --version
Ubuntu clang version 15.0.0-++20220320052914+3b2e605e33bd-1~exp1~20220320173006.195
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin

$ lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 20.04.4 LTS
Release:	20.04
Codename:	focal

Minimal repro

template<class F>
struct hello {
	consteval hello(F)
	{
	}
};
constexpr hello hello_consteval = []() noexcept -> void {};

template<class F>
struct world {
	consteval world(F)
	{
	}
};
constexpr world world_consteval = []() noexcept -> void {};

Godbolt
Note that deleting one hello xor world will result in successful compilation.

Diagnostic

$ /usr/bin/clang++ -std=c++2b fail.cpp 

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: /usr/lib/llvm-15/bin/clang -cc1 -triple x86_64-pc-linux-gnu -emit-obj -mrelax-all --mrelax-relocations -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name fail.cpp -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -mllvm -treat-scalable-fixed-error-as-warning -debugger-tuning=gdb -fcoverage-compilation-dir=/tmp -resource-dir /usr/lib/llvm-15/lib/clang/15.0.0 -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11 -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/x86_64-linux-gnu/c++/11 -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../include/c++/11/backward -internal-isystem /usr/lib/llvm-15/lib/clang/15.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/11/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -std=c++2b -fdeprecated-macro -fdebug-compilation-dir=/tmp -ferror-limit 19 -fgnuc-version=4.2.1 -fcxx-exceptions -fexceptions -fcolor-diagnostics -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/fail-65fc30.o -x c++ fail.cpp
1.	<eof> parser at end of file
 #0 0x00007ff8d8dde561 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/lib/x86_64-linux-gnu/libLLVM-15.so.1+0xe1d561)
 #1 0x00007ff8d8ddc2be llvm::sys::RunSignalHandlers() (/lib/x86_64-linux-gnu/libLLVM-15.so.1+0xe1b2be)
 #2 0x00007ff8d8ddea8b (/lib/x86_64-linux-gnu/libLLVM-15.so.1+0xe1da8b)
 #3 0x00007ff8e22733c0 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x143c0)
 #4 0x00007ff8df69ee4f (/lib/x86_64-linux-gnu/libclang-cpp.so.15+0xd69e4f)
 #5 0x00007ff8df6a241b (/lib/x86_64-linux-gnu/libclang-cpp.so.15+0xd6d41b)
 #6 0x00007ff8df6525b1 (/lib/x86_64-linux-gnu/libclang-cpp.so.15+0xd1d5b1)
 #7 0x00007ff8df6521e4 clang::Expr::EvaluateAsConstantExpr(clang::Expr::EvalResult&, clang::ASTContext const&, clang::Expr::ConstantExprKind) const (/lib/x86_64-linux-gnu/libclang-cpp.so.15+0xd1d1e4)
 #8 0x00007ff8dfd5d57f clang::Sema::PopExpressionEvaluationContext() (/lib/x86_64-linux-gnu/libclang-cpp.so.15+0x142857f)
 #9 0x00007ff8df36aa65 clang::ParseAST(clang::Sema&, bool, bool) (/lib/x86_64-linux-gnu/libclang-cpp.so.15+0xa35a65)
#10 0x00007ff8e052b0f5 clang::CodeGenAction::ExecuteAction() (/lib/x86_64-linux-gnu/libclang-cpp.so.15+0x1bf60f5)
#11 0x00007ff8e0ecd3e7 clang::FrontendAction::Execute() (/lib/x86_64-linux-gnu/libclang-cpp.so.15+0x25983e7)
#12 0x00007ff8e0e44136 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/lib/x86_64-linux-gnu/libclang-cpp.so.15+0x250f136)
#13 0x00007ff8e0f486ca clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/lib/x86_64-linux-gnu/libclang-cpp.so.15+0x26136ca)
#14 0x0000000000413644 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/usr/lib/llvm-15/bin/clang+0x413644)
#15 0x00000000004119bb (/usr/lib/llvm-15/bin/clang+0x4119bb)
#16 0x0000000000411807 main (/usr/lib/llvm-15/bin/clang+0x411807)
#17 0x00007ff8d7a6d0b3 __libc_start_main /build/glibc-sMfBJT/glibc-2.31/csu/../csu/libc-start.c:342:3
#18 0x000000000040e41e _start (/usr/lib/llvm-15/bin/clang+0x40e41e)
clang: error: unable to execute command: Segmentation fault (core dumped)
clang: error: clang frontend command failed due to signal (use -v to see invocation)
Ubuntu clang version 15.0.0-++20220320052914+3b2e605e33bd-1~exp1~20220320173006.195
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
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: 
[fail-4786e0.sh.txt](https://github.com/llvm/llvm-project/files/8358292/fail-4786e0.sh.txt)
[fail-4786e0.cpp.txt](https://github.com/llvm/llvm-project/files/8358291/fail-4786e0.cpp.txt)
clang: note: diagnostic msg: /tmp/fail-4786e0.sh
clang: note: diagnostic msg: 

********************

fail-4786e0.cpp.txt
fail-4786e0.sh.txt

Files suffixed with .txt to avoid GitHub rejecting them.

[llvmbot]

@llvm/issue-subscribers-clang-frontend

[cjdb]

@cor3ntin suggested that this might be a triplicate issue. After a bit of chatting, we realised that there's both an unevaluated lambda problem that's seemingly related. This problem is to do with consteval, and can be easily verified by changing the keyword to constexpr.

[llvmbot]

@llvm/issue-subscribers-c-20