Clang 17 crashes when `requires` clause accesses parameter value [C++20]

[Curve]

When a templated class with a templated method uses a requires clause which references a method argument the compiler crashes.

Tested on: Clang 17.0.5, 17.0.6, Trunk

This did not happen on Clang 16.

Note

This only happens when the class the method resides in is templated as well

Reproduction Example:

#include <concepts>
#include <utility>


template <typename Type>
struct some_struct
{
    template <typename O>
    void test(Type& target, O&& value) &
        requires std::assignable_from<Type&, decltype(std::forward<O>(value))>;
};

template <typename Type>
template <typename O>
void some_struct<Type>::test(Type& target, O&& value) &
    requires std::assignable_from<Type&, decltype(std::forward<O>(value))>
{
    target = std::forward<O>(value);
}

int main()
{
    some_struct<int> a;

    int val = 10;
    a.test(val, 20);

    return 0;
}

Crash Log:

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/llvm17/bin/clang++ -cc1 -triple x86_64-alpine-linux-musl -emit-obj -mrelax-all -dumpdir a- -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name reprod.cpp -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -ffp-contract=on -fno-rounding-math -mconstructor-alia/work # clang++ -std=c++20 reprod.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/llvm17/bin/clang++ -cc1 -triple x86_64-alpine-linux-musl -emit-obj -mrelax-all -dumpdir a- -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name reprod.cpp -m/work # clang++ -std=c++20 reprod.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/llvm17/bin/clang++ -cc1 -triple x86_64-alpine-linux-musl -emit-obj -mrelax-all -dumpdir a- -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name reprod.cpp -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/work -resource-dir /usr/lib/llvm17/lib/clang/17 -internal-isystem /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/13.2.1/../../../../include/c++/13.2.1 -internal-isystem /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/13.2.1/../../../../include/c++/13.2.1/x86_64-alpine-linux-musl -internal-isystem /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/13.2.1/../../../../include/c++/13.2.1/backward -internal-isystem /usr/local/include -internal-isystem /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/13.2.1/../../../../x86_64-alpine-linux-musl/include -internal-externc-isystem /usr/include/fortify -internal-externc-isystem /usr/include -internal-isystem /usr/lib/llvm17/lib/clang/17/include -std=c++20 -fdeprecated-macro -fdebug-compilation-dir=/work -ferror-limit 19 -stack-protector 2 -fgnuc-version=4.2.1 -fno-implicit-modules -fcxx-exceptions -fexceptions -fcolor-diagnostics -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/reprod-4033ce.o -x c++ reprod.cpp
1.      reprod.cpp:16:1: current parser token '{'
clang++: error: unable to execute command: Segmentation fault (core dumped)
clang++: error: clang frontend command failed due to signal (use -v to see invocation)
Alpine clang version 17.0.5
Target: x86_64-alpine-linux-musl
Thread model: posix
InstalledDir: /usr/bin
Configuration file: /etc/clang17/x86_64-alpine-linux-musl.cfg
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/reprod-2638ac.cpp
clang++: note: diagnostic msg: /tmp/reprod-2638ac.sh
clang++: note: diagnostic msg: 

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

Godbolt Reproduction Example: https://godbolt.org/z/Yv7oKK4KM

files.zip

[Curve]

More detailed stack trace from assertions trunk:

clang++: /root/llvm-project/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp:6210: clang::NamedDecl* clang::Sema::FindInstantiatedDecl(clang::SourceLocation, clang::NamedDecl*, const clang::MultiLevelTemplateArgumentList&, bool): Assertion `isa<LabelDecl>(D)' 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 -mllvm --x86-asm-syntax=intel -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics -std=c++20 <source>
1.	<source>:17:1: current parser token '{'
 #0 0x000000000378dc48 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x378dc48)
 #1 0x000000000378b92c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x378b92c)
 #2 0x00000000036d4448 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007f6c4d442520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x00007f6c4d4969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x00007f6c4d442476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x00007f6c4d4287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x00007f6c4d42871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #8 0x00007f6c4d439e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #9 0x0000000006ae76ea clang::Sema::FindInstantiatedDecl(clang::SourceLocation, clang::NamedDecl*, clang::MultiLevelTemplateArgumentList const&, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6ae76ea)
#10 0x0000000006a4bde1 (anonymous namespace)::TemplateInstantiator::TransformDecl(clang::SourceLocation, clang::Decl*) SemaTemplateInstantiate.cpp:0:0
#11 0x0000000006a83c30 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformDeclRefExpr(clang::DeclRefExpr*) SemaTemplateInstantiate.cpp:0:0
#12 0x0000000006a8410b (anonymous namespace)::TemplateInstantiator::TransformDeclRefExpr(clang::DeclRefExpr*) SemaTemplateInstantiate.cpp:0:0
#13 0x0000000006a60eab clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformExpr(clang::Expr*) SemaTemplateInstantiate.cpp:0:0
#14 0x0000000006a61898 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformInitializer(clang::Expr*, bool) (.part.0) SemaTemplateInstantiate.cpp:0:0
#15 0x0000000006a620a8 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformExprs(clang::Expr* const*, unsigned int, bool, llvm::SmallVectorImpl<clang::Expr*>&, bool*) SemaTemplateInstantiate.cpp:0:0
#16 0x0000000006a6b3a1 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformCallExpr(clang::CallExpr*) SemaTemplateInstantiate.cpp:0:0
#17 0x0000000006a60f98 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformExpr(clang::Expr*) SemaTemplateInstantiate.cpp:0:0
#18 0x0000000006a6fa20 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformType(clang::TypeLocBuilder&, clang::TypeLoc) SemaTemplateInstantiate.cpp:0:0
#19 0x0000000006a7528a clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformType(clang::TypeSourceInfo*) SemaTemplateInstantiate.cpp:0:0
#20 0x0000000006a79900 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformTemplateArgument(clang::TemplateArgumentLoc const&, clang::TemplateArgumentLoc&, bool) SemaTemplateInstantiate.cpp:0:0
#21 0x0000000006a7b275 bool clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformTemplateArguments<clang::TemplateArgumentLoc const*>(clang::TemplateArgumentLoc const*, clang::TemplateArgumentLoc const*, clang::TemplateArgumentListInfo&, bool) (.constprop.0) SemaTemplateInstantiate.cpp:0:0
#22 0x0000000006a7b83e clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformConceptSpecializationExpr(clang::ConceptSpecializationExpr*) SemaTemplateInstantiate.cpp:0:0
#23 0x0000000006a60ed3 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformExpr(clang::Expr*) SemaTemplateInstantiate.cpp:0:0
#24 0x0000000006a968a8 clang::Sema::SubstConstraintExpr(clang::Expr*, clang::MultiLevelTemplateArgumentList const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6a968a8)
#25 0x00000000061e04cc SubstituteConstraintExpression(clang::Sema&, clang::Sema::TemplateCompareNewDeclInfo const&, clang::Expr const*) SemaConcept.cpp:0:0
#26 0x00000000061eb1c2 clang::Sema::AreConstraintExpressionsEqual(clang::NamedDecl const*, clang::Expr const*, clang::Sema::TemplateCompareNewDeclInfo const&, clang::Expr const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x61eb1c2)
#27 0x00000000068262b8 IsOverloadOrOverrideImpl(clang::Sema&, clang::FunctionDecl*, clang::FunctionDecl*, bool, bool, bool) SemaOverload.cpp:0:0
#28 0x00000000068269a6 clang::Sema::CheckOverload(clang::Scope*, clang::FunctionDecl*, clang::LookupResult const&, clang::NamedDecl*&, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x68269a6)
#29 0x00000000062b8b6d clang::Sema::CheckFunctionDeclaration(clang::Scope*, clang::FunctionDecl*, clang::LookupResult&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x62b8b6d)
#30 0x00000000062bf936 clang::Sema::ActOnFunctionDeclarator(clang::Scope*, clang::Declarator&, clang::DeclContext*, clang::TypeSourceInfo*, clang::LookupResult&, llvm::MutableArrayRef<clang::TemplateParameterList*>, bool&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x62bf936)
#31 0x00000000062c37b3 clang::Sema::HandleDeclarator(clang::Scope*, clang::Declarator&, llvm::MutableArrayRef<clang::TemplateParameterList*>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x62c37b3)
#32 0x00000000062c433f clang::Sema::ActOnStartOfFunctionDef(clang::Scope*, clang::Declarator&, llvm::MutableArrayRef<clang::TemplateParameterList*>, clang::Sema::SkipBodyInfo*, clang::Sema::FnBodyKind) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x62c433f)
#33 0x0000000005f4f55e clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5f4f55e)
#34 0x0000000006040740 clang::Parser::ParseSingleDeclarationAfterTemplate(clang::DeclaratorContext, clang::Parser::ParsedTemplateInfo const&, clang::ParsingDeclRAIIObject&, clang::SourceLocation&, clang::ParsedAttributes&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6040740)
#35 0x0000000006045c78 clang::Parser::ParseTemplateDeclarationOrSpecialization(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::AccessSpecifier) (.part.0) ParseTemplate.cpp:0:0
#36 0x0000000006045f33 clang::Parser::ParseDeclarationStartingWithTemplate(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6045f33)
#37 0x0000000005f829e9 clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5f829e9)
#38 0x0000000005f4ba6e clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5f4ba6e)
#39 0x0000000005f4c8ed clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5f4c8ed)
#40 0x0000000005f3f82a clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5f3f82a)
#41 0x0000000004009ea8 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4009ea8)
#42 0x0000000004274d29 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4274d29)
#43 0x00000000041f4e6e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x41f4e6e)
#44 0x0000000004353fce clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4353fce)
#45 0x0000000000c01106 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xc01106)
#46 0x0000000000bf89ca ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#47 0x000000000404b1c9 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
#48 0x00000000036d48f4 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x36d48f4)
#49 0x000000000404b7bf 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
#50 0x0000000004013735 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4013735)
#51 0x000000000401419d 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+++0x401419d)
#52 0x000000000401c0c5 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x401c0c5)
#53 0x0000000000bfe5ac clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xbfe5ac)
#54 0x0000000000af76b1 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xaf76b1)
#55 0x00007f6c4d429d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#56 0x00007f6c4d429e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#57 0x0000000000bf84ae _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xbf84ae)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134

[llvmbot]

@llvm/issue-subscribers-c-20

Author: Noah (Curve)

When a templated class with a templated method uses a `requires` clause which references a method argument the compiler crashes.

Tested on: Clang 17.0.5, 17.0.6, Trunk

This did not happen on Clang 16.

> [!NOTE]
> This only happens when the class the method resides in is templated as well

Reproduction Example:

#include <concepts>
#include <utility>


template <typename Type>
struct some_struct
{
    template <typename O>
    void test(Type& target, O&& value) &
        requires std::assignable_from<Type&, decltype(std::forward<O>(value))>;
};

template <typename Type>
template <typename O>
void some_struct<Type>::test(Type& target, O&& value) &
    requires std::assignable_from<Type&, decltype(std::forward<O>(value))>
{
    target = std::forward<O>(value);
}

int main()
{
    some_struct<int> a;

    int val = 10;
    a.test(val, 20);

    return 0;
}

Crash Log:

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/llvm17/bin/clang++ -cc1 -triple x86_64-alpine-linux-musl -emit-obj -mrelax-all -dumpdir a- -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name reprod.cpp -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -ffp-contract=on -fno-rounding-math -mconstructor-alia/work # clang++ -std=c++20 reprod.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/llvm17/bin/clang++ -cc1 -triple x86_64-alpine-linux-musl -emit-obj -mrelax-all -dumpdir a- -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name reprod.cpp -m/work # clang++ -std=c++20 reprod.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/llvm17/bin/clang++ -cc1 -triple x86_64-alpine-linux-musl -emit-obj -mrelax-all -dumpdir a- -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name reprod.cpp -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/work -resource-dir /usr/lib/llvm17/lib/clang/17 -internal-isystem /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/13.2.1/../../../../include/c++/13.2.1 -internal-isystem /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/13.2.1/../../../../include/c++/13.2.1/x86_64-alpine-linux-musl -internal-isystem /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/13.2.1/../../../../include/c++/13.2.1/backward -internal-isystem /usr/local/include -internal-isystem /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/13.2.1/../../../../x86_64-alpine-linux-musl/include -internal-externc-isystem /usr/include/fortify -internal-externc-isystem /usr/include -internal-isystem /usr/lib/llvm17/lib/clang/17/include -std=c++20 -fdeprecated-macro -fdebug-compilation-dir=/work -ferror-limit 19 -stack-protector 2 -fgnuc-version=4.2.1 -fno-implicit-modules -fcxx-exceptions -fexceptions -fcolor-diagnostics -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/reprod-4033ce.o -x c++ reprod.cpp
1.      reprod.cpp:16:1: current parser token '{'
clang++: error: unable to execute command: Segmentation fault (core dumped)
clang++: error: clang frontend command failed due to signal (use -v to see invocation)
Alpine clang version 17.0.5
Target: x86_64-alpine-linux-musl
Thread model: posix
InstalledDir: /usr/bin
Configuration file: /etc/clang17/x86_64-alpine-linux-musl.cfg
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/reprod-2638ac.cpp
clang++: note: diagnostic msg: /tmp/reprod-2638ac.sh
clang++: note: diagnostic msg: 

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

Godbolt Reproduction Example: https://godbolt.org/z/Yv7oKK4KM

files.zip

[llvmbot]

@llvm/issue-subscribers-clang-frontend

Author: Noah (Curve)

When a templated class with a templated method uses a `requires` clause which references a method argument the compiler crashes.

Tested on: Clang 17.0.5, 17.0.6, Trunk

This did not happen on Clang 16.

> [!NOTE]
> This only happens when the class the method resides in is templated as well

Reproduction Example:

#include <concepts>
#include <utility>


template <typename Type>
struct some_struct
{
    template <typename O>
    void test(Type& target, O&& value) &
        requires std::assignable_from<Type&, decltype(std::forward<O>(value))>;
};

template <typename Type>
template <typename O>
void some_struct<Type>::test(Type& target, O&& value) &
    requires std::assignable_from<Type&, decltype(std::forward<O>(value))>
{
    target = std::forward<O>(value);
}

int main()
{
    some_struct<int> a;

    int val = 10;
    a.test(val, 20);

    return 0;
}

Crash Log:

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/llvm17/bin/clang++ -cc1 -triple x86_64-alpine-linux-musl -emit-obj -mrelax-all -dumpdir a- -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name reprod.cpp -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -ffp-contract=on -fno-rounding-math -mconstructor-alia/work # clang++ -std=c++20 reprod.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/llvm17/bin/clang++ -cc1 -triple x86_64-alpine-linux-musl -emit-obj -mrelax-all -dumpdir a- -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name reprod.cpp -m/work # clang++ -std=c++20 reprod.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/llvm17/bin/clang++ -cc1 -triple x86_64-alpine-linux-musl -emit-obj -mrelax-all -dumpdir a- -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name reprod.cpp -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fcoverage-compilation-dir=/work -resource-dir /usr/lib/llvm17/lib/clang/17 -internal-isystem /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/13.2.1/../../../../include/c++/13.2.1 -internal-isystem /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/13.2.1/../../../../include/c++/13.2.1/x86_64-alpine-linux-musl -internal-isystem /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/13.2.1/../../../../include/c++/13.2.1/backward -internal-isystem /usr/local/include -internal-isystem /usr/bin/../lib/gcc/x86_64-alpine-linux-musl/13.2.1/../../../../x86_64-alpine-linux-musl/include -internal-externc-isystem /usr/include/fortify -internal-externc-isystem /usr/include -internal-isystem /usr/lib/llvm17/lib/clang/17/include -std=c++20 -fdeprecated-macro -fdebug-compilation-dir=/work -ferror-limit 19 -stack-protector 2 -fgnuc-version=4.2.1 -fno-implicit-modules -fcxx-exceptions -fexceptions -fcolor-diagnostics -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/reprod-4033ce.o -x c++ reprod.cpp
1.      reprod.cpp:16:1: current parser token '{'
clang++: error: unable to execute command: Segmentation fault (core dumped)
clang++: error: clang frontend command failed due to signal (use -v to see invocation)
Alpine clang version 17.0.5
Target: x86_64-alpine-linux-musl
Thread model: posix
InstalledDir: /usr/bin
Configuration file: /etc/clang17/x86_64-alpine-linux-musl.cfg
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/reprod-2638ac.cpp
clang++: note: diagnostic msg: /tmp/reprod-2638ac.sh
clang++: note: diagnostic msg: 

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

Godbolt Reproduction Example: https://godbolt.org/z/Yv7oKK4KM

files.zip

[zyn0217]

Similar to #73418 according to the same assertion message. Not sure if they're connected.

[Curve]

Similar to #73418 according to the same assertion message. Not sure if they're connected.

Note that this issue (#74447) seems to be either a regression or a bug introduced in clang17 - So if #73418 also didn't occur in clang16 downwards they could very well be related

[shafik]

It looks like #73418 regressed after clang-15

[zyn0217]

Reduced version without headers:

template <typename T> struct S {
  template <typename U>
  void test(T target, U value)
    requires (__is_same(decltype(value), T));
};

template <typename T>
template <typename U>
void S<T>::test(T target, U value)
  requires (__is_same(decltype(value), T)) {}

The out-of-line definition is in some way necessary for reproduction.