Clang crashes with requires expression in lambda in concept constraints

[namniav]

https://godbolt.org/z/Kvr6afWd4

template<typename T> concept doesnt_matter = true;

template<class T>
concept test = 
    []{
        return requires(T t) {
            { t } -> doesnt_matter;
        };
    }();

static_assert(test<int>);

It is reduced from https://godbolt.org/z/5K6janbx5

#include <concepts>
#include <type_traits>
#include <utility>
#include <tuple>

template<class T>
concept tuple_like = 
    [] <std::size_t...I> (std::index_sequence<I...>) {
        return ((requires(T t) {
                    { std::get<I>(t) } -> std::convertible_to<std::tuple_element_t<I, T>&>;
                }) && ...);
    } (std::make_index_sequence<std::tuple_size_v<T>>{});

static_assert(tuple_like<std::tuple<int>>);

Both were accepted by Clang 15 and earlier. Clang 16 and current trunk on CompilerExplorer crashes on them(with either libc++ or libstdc++), but accepts the second if std::tuple_element_t<I, T>& is replaced with int&.

GCC also has this issue on the second example only: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105644.

MSVC accepts them.

[llvmbot]

@llvm/issue-subscribers-c-20

[llvmbot]

@llvm/issue-subscribers-clang-frontend

[shafik]

Confirmed, using assertions build is usually preferred since any assertions hit usually points better to the underlying issue.

Assertion:

clang++: /root/llvm-project/clang/lib/Sema/SemaTemplateInstantiate.cpp:2224:
clang::QualType {anonymous}::TemplateInstantiator::TransformTemplateTypeParmType(clang::TypeLocBuilder&, clang::TemplateTypeParmTypeLoc, bool):
Assertion `Arg.getKind() == TemplateArgument::Type && "Template argument kind mismatch"' failed.

Backtrace:

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 -Wall <source>
1.	<source>:14:42: current parser token ')'
2.	<source>:8:5: instantiating function definition '(anonymous class)::operator()<0UL>'
 #0 0x000000000367eca8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x367eca8)
 #1 0x000000000367cb2c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x367cb2c)
 #2 0x00000000035c8568 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007fe2d3ece420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
 #4 0x00007fe2d399100b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4300b)
 #5 0x00007fe2d3970859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22859)
 #6 0x00007fe2d3970729 (/lib/x86_64-linux-gnu/libc.so.6+0x22729)
 #7 0x00007fe2d3981fd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
 #8 0x0000000006893cd3 (anonymous namespace)::TemplateInstantiator::TransformTemplateTypeParmType(clang::TypeLocBuilder&, clang::TemplateTypeParmTypeLoc, bool) SemaTemplateInstantiate.cpp:0:0
 #9 0x00000000068b550e clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformType(clang::TypeLocBuilder&, clang::TypeLoc) SemaTemplateInstantiate.cpp:0:0
#10 0x00000000068bb1da clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformType(clang::TypeSourceInfo*) SemaTemplateInstantiate.cpp:0:0
#11 0x00000000068c04b8 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformTemplateArgument(clang::TemplateArgumentLoc const&, clang::TemplateArgumentLoc&, bool) SemaTemplateInstantiate.cpp:0:0
#12 0x00000000068c39d8 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformTemplateSpecializationType(clang::TypeLocBuilder&, clang::TemplateSpecializationTypeLoc, clang::TemplateName) SemaTemplateInstantiate.cpp:0:0
#13 0x00000000068b6452 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformType(clang::TypeLocBuilder&, clang::TypeLoc) SemaTemplateInstantiate.cpp:0:0
#14 0x00000000068cba0d clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformElaboratedType(clang::TypeLocBuilder&, clang::ElaboratedTypeLoc) SemaTemplateInstantiate.cpp:0:0
#15 0x00000000068b5d3f clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformType(clang::TypeLocBuilder&, clang::TypeLoc) SemaTemplateInstantiate.cpp:0:0
#16 0x00000000068baab2 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformReferenceType(clang::TypeLocBuilder&, clang::ReferenceTypeLoc) SemaTemplateInstantiate.cpp:0:0
#17 0x00000000068b52d9 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformType(clang::TypeLocBuilder&, clang::TypeLoc) SemaTemplateInstantiate.cpp:0:0
#18 0x00000000068bb1da clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformType(clang::TypeSourceInfo*) SemaTemplateInstantiate.cpp:0:0
#19 0x00000000068c04b8 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformTemplateArgument(clang::TemplateArgumentLoc const&, clang::TemplateArgumentLoc&, bool) SemaTemplateInstantiate.cpp:0:0
#20 0x00000000068c1d55 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
#21 0x00000000068c23fb clang::Sema::SubstTypeConstraint(clang::TemplateTypeParmDecl*, clang::TypeConstraint const*, clang::MultiLevelTemplateArgumentList const&, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x68c23fb)
#22 0x00000000068ec6d8 clang::TemplateDeclInstantiator::VisitTemplateTypeParmDecl(clang::TemplateTypeParmDecl*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x68ec6d8)
#23 0x000000000693e250 clang::TemplateDeclInstantiator::SubstTemplateParams(clang::TemplateParameterList*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x693e250)
#24 0x00000000068b3e89 (anonymous namespace)::TemplateInstantiator::TransformExprRequirement(clang::concepts::ExprRequirement*) SemaTemplateInstantiate.cpp:0:0
#25 0x00000000068d1299 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformRequiresExpr(clang::RequiresExpr*) SemaTemplateInstantiate.cpp:0:0
#26 0x00000000068d259e (anonymous namespace)::TemplateInstantiator::TransformRequiresExpr(clang::RequiresExpr*) SemaTemplateInstantiate.cpp:0:0
#27 0x00000000068a5232 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformExpr(clang::Expr*) SemaTemplateInstantiate.cpp:0:0
#28 0x00000000068b2588 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformParenExpr(clang::ParenExpr*) SemaTemplateInstantiate.cpp:0:0
#29 0x00000000068a52cb clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformExpr(clang::Expr*) SemaTemplateInstantiate.cpp:0:0
#30 0x00000000068ad910 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformCXXFoldExpr(clang::CXXFoldExpr*) SemaTemplateInstantiate.cpp:0:0
#31 0x00000000068a5779 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformExpr(clang::Expr*) SemaTemplateInstantiate.cpp:0:0
#32 0x00000000068a6068 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformInitializer(clang::Expr*, bool) (.part.0) SemaTemplateInstantiate.cpp:0:0
#33 0x00000000068a63ec clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformReturnStmt(clang::ReturnStmt*) SemaTemplateInstantiate.cpp:0:0
#34 0x00000000068df859 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformCompoundStmt(clang::CompoundStmt*, bool) SemaTemplateInstantiate.cpp:0:0
#35 0x00000000068e376a clang::Sema::SubstStmt(clang::Stmt*, clang::MultiLevelTemplateArgumentList const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x68e376a)
#36 0x00000000069336eb clang::Sema::InstantiateFunctionDefinition(clang::SourceLocation, clang::FunctionDecl*, bool, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x69336eb)
#37 0x0000000005ee92c1 clang::Sema::runWithSufficientStackSpace(clang::SourceLocation, llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5ee92c1)
#38 0x000000000681a9e2 clang::Sema::DeduceReturnType(clang::FunctionDecl*, clang::SourceLocation, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x681a9e2)
#39 0x00000000062cd142 clang::Sema::DiagnoseUseOfDecl(clang::NamedDecl*, llvm::ArrayRef<clang::SourceLocation>, clang::ObjCInterfaceDecl const*, bool, bool, clang::ObjCInterfaceDecl*, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x62cd142)
#40 0x0000000006663397 CreateFunctionRefExpr(clang::Sema&, clang::FunctionDecl*, clang::NamedDecl*, clang::Expr const*, bool, clang::SourceLocation, clang::DeclarationNameLoc const&) SemaOverload.cpp:0:0
#41 0x00000000066a0759 clang::Sema::BuildCallToObjectOfClassType(clang::Scope*, clang::Expr*, clang::SourceLocation, llvm::MutableArrayRef<clang::Expr*>, clang::SourceLocation) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66a0759)
#42 0x0000000006340e18 clang::Sema::BuildCallExpr(clang::Scope*, clang::Expr*, clang::SourceLocation, llvm::MutableArrayRef<clang::Expr*>, clang::SourceLocation, clang::Expr*, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6340e18)
#43 0x0000000006342c8c clang::Sema::ActOnCallExpr(clang::Scope*, clang::Expr*, clang::SourceLocation, llvm::MutableArrayRef<clang::Expr*>, clang::SourceLocation, clang::Expr*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6342c8c)
#44 0x00000000068af2d0 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformCallExpr(clang::CallExpr*) SemaTemplateInstantiate.cpp:0:0
#45 0x00000000068a56d2 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformExpr(clang::Expr*) SemaTemplateInstantiate.cpp:0:0
#46 0x00000000068e3d58 clang::Sema::SubstConstraintExpr(clang::Expr*, clang::MultiLevelTemplateArgumentList const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x68e3d58)
#47 0x0000000006043e37 calculateConstraintSatisfaction(clang::Sema&, clang::NamedDecl const*, clang::SourceLocation, clang::MultiLevelTemplateArgumentList const&, clang::Expr const*, clang::ConstraintSatisfaction&)::'lambda'(clang::Expr const*)::operator()(clang::Expr const*) const SemaConcept.cpp:0:0
#48 0x000000000604548b clang::ActionResult<clang::Expr*, true> calculateConstraintSatisfaction<calculateConstraintSatisfaction(clang::Sema&, clang::NamedDecl const*, clang::SourceLocation, clang::MultiLevelTemplateArgumentList const&, clang::Expr const*, clang::ConstraintSatisfaction&)::'lambda'(clang::Expr const*)>(clang::Sema&, clang::Expr const*, clang::ConstraintSatisfaction&, calculateConstraintSatisfaction(clang::Sema&, clang::NamedDecl const*, clang::SourceLocation, clang::MultiLevelTemplateArgumentList const&, clang::Expr const*, clang::ConstraintSatisfaction&)::'lambda'(clang::Expr const*)&&) SemaConcept.cpp:0:0
#49 0x0000000006045c92 CheckConstraintSatisfaction(clang::Sema&, clang::NamedDecl const*, llvm::ArrayRef<clang::Expr const*>, llvm::SmallVectorImpl<clang::Expr*>&, clang::MultiLevelTemplateArgumentList const&, clang::SourceRange, clang::ConstraintSatisfaction&) SemaConcept.cpp:0:0
#50 0x00000000060462ca clang::Sema::CheckConstraintSatisfaction(clang::NamedDecl const*, llvm::ArrayRef<clang::Expr const*>, llvm::SmallVectorImpl<clang::Expr*>&, clang::MultiLevelTemplateArgumentList const&, clang::SourceRange, clang::ConstraintSatisfaction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x60462ca)
#51 0x000000000675cc0e clang::Sema::CheckConceptTemplateId(clang::CXXScopeSpec const&, clang::SourceLocation, clang::DeclarationNameInfo const&, clang::NamedDecl*, clang::ConceptDecl*, clang::TemplateArgumentListInfo const*) (.constprop.0) SemaTemplate.cpp:0:0
#52 0x000000000675eb87 clang::Sema::BuildTemplateIdExpr(clang::CXXScopeSpec const&, clang::SourceLocation, clang::LookupResult&, bool, clang::TemplateArgumentListInfo const*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x675eb87)
#53 0x0000000006322a6c clang::Sema::ActOnIdExpression(clang::Scope*, clang::CXXScopeSpec&, clang::SourceLocation, clang::UnqualifiedId&, bool, bool, clang::CorrectionCandidateCallback*, bool, clang::Token*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6322a6c)
#54 0x0000000005e19986 clang::Parser::tryParseCXXIdExpression(clang::CXXScopeSpec&, bool, clang::Token&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5e19986)
#55 0x0000000005e19bd4 clang::Parser::ParseCXXIdExpression(bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5e19bd4)
#56 0x0000000005dfd3da clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, bool&, clang::Parser::TypeCastState, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5dfd3da)
#57 0x0000000005dfdc85 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, bool&, clang::Parser::TypeCastState, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5dfdc85)
#58 0x0000000005e0a1b3 clang::Parser::ParseConstantExpressionInExprEvalContext(clang::Parser::TypeCastState) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5e0a1b3)
#59 0x0000000005de49e4 clang::Parser::ParseStaticAssertDeclaration(clang::SourceLocation&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5de49e4)
#60 0x0000000005dd63d9 clang::Parser::ParseDeclaration(clang::DeclaratorContext, clang::SourceLocation&, clang::ParsedAttributes&, clang::ParsedAttributes&, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5dd63d9)
#61 0x0000000005da2074 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5da2074)
#62 0x0000000005da2f3d clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5da2f3d)
#63 0x0000000005d972ca clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x5d972ca)
#64 0x00000000048d7f18 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x48d7f18)
#65 0x000000000413f719 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x413f719)
#66 0x00000000040c36de clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x40c36de)
#67 0x000000000421fdb6 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x421fdb6)
#68 0x0000000000bce557 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xbce557)
#69 0x0000000000bc6c0a ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#70 0x0000000003f22a69 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
#71 0x00000000035c8a14 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x35c8a14)
#72 0x0000000003f2305f 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
#73 0x0000000003eeb925 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3eeb925)
#74 0x0000000003eec38d 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+++0x3eec38d)
#75 0x0000000003ef42e5 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3ef42e5)
#76 0x0000000000bcc7ec clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xbcc7ec)
#77 0x0000000000ac59d1 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xac59d1)
#78 0x00007fe2d3972083 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24083)
#79 0x0000000000bc66ee _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0xbc66ee)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134

[shafik]

CC @erichkeane