Clang accepts constraints not satisfied function

[llvmbot]

Bugzilla Link	49755
Version	trunk
OS	All
Reporter	LLVM Bugzilla Contributor
CC	@zygoloid

Extended Description

https://godbolt.org/z/1eb7axon5

#include <concepts>

template <typename... Ts>
auto f(Ts...) {
  return [](std::same_as<Ts> auto...) {};
}

int main() {
  f(0)(0u);
}

[llvmbot]

And this form will trigger parser error:

https://godbolt.org/z/fan51h1j4

#include <concepts>

template <typename... Ts>
auto f(Ts...) {
  return []<std::same_as<Ts> auto> {};
}

int main() {
  f(0).template operator()<0>();
}

[royjacobson]

The first one works now (since Clang 13), but the second one is still an ICE. Impressively, it doesn't compile in any compiler. https://godbolt.org/z/YqE4rddMa

[llvmbot]

@llvm/issue-subscribers-clang-frontend

[shafik]

Looks related to #35923

[shafik]

Assertion: https://godbolt.org/z/YfdKMhsWc

clang++: /root/llvm-project/clang/lib/Sema/SemaTemplate.cpp:7813: clang::ExprResult 
clang::Sema::BuildExpressionFromIntegralTemplateArgument(const clang::TemplateArgument&, clang::SourceLocation): 
Assertion `Arg.getKind() == TemplateArgument::Integral && "Operation is only valid for integral template arguments"' 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 <source>
1.	<source>:9:36: current parser token ')'
2.	<source>:8:12: parsing function body 'main'
3.	<source>:8:12: in compound statement ('{}')
 #0 0x0000560ef68e7cd4 PrintStackTraceSignalHandler(void*) Signals.cpp:0:0
 #1 0x0000560ef68e5a6c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3fada6c)
 #2 0x0000560ef681c818 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x00007f410d203420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
 #4 0x00007f410ccd000b raise (/lib/x86_64-linux-gnu/libc.so.6+0x4300b)
 #5 0x00007f410ccaf859 abort (/lib/x86_64-linux-gnu/libc.so.6+0x22859)
 #6 0x00007f410ccaf729 (/lib/x86_64-linux-gnu/libc.so.6+0x22729)
 #7 0x00007f410ccc0fd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
 #8 0x0000560ef977f4b8 clang::Sema::BuildExpressionFromIntegralTemplateArgument(clang::TemplateArgument const&, clang::SourceLocation) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6e474b8)
 #9 0x0000560ef98fd1df (anonymous namespace)::TemplateInstantiator::transformNonTypeTemplateParmRef(clang::Decl*, clang::NonTypeTemplateParmDecl const*, clang::SourceLocation, clang::TemplateArgument, llvm::Optional<unsigned int>) SemaTemplateInstantiate.cpp:0:0
#10 0x0000560ef990a37f (anonymous namespace)::TemplateInstantiator::TransformDeclRefExpr(clang::DeclRefExpr*) SemaTemplateInstantiate.cpp:0:0
#11 0x0000560ef98e6481 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformExpr(clang::Expr*) SemaTemplateInstantiate.cpp:0:0
#12 0x0000560ef98f58ce clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformType(clang::TypeLocBuilder&, clang::TypeLoc) SemaTemplateInstantiate.cpp:0:0
#13 0x0000560ef98fb6a4 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformType(clang::TypeSourceInfo*) SemaTemplateInstantiate.cpp:0:0
#14 0x0000560ef98ff8d8 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformTemplateArgument(clang::TemplateArgumentLoc const&, clang::TemplateArgumentLoc&, bool) SemaTemplateInstantiate.cpp:0:0
#15 0x0000560ef99011a5 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
#16 0x0000560ef99016ed clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformConceptSpecializationExpr(clang::ConceptSpecializationExpr*) SemaTemplateInstantiate.cpp:0:0
#17 0x0000560ef98e64a9 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformExpr(clang::Expr*) SemaTemplateInstantiate.cpp:0:0
#18 0x0000560ef991ad6c clang::Sema::SubstConstraintExpr(clang::Expr*, clang::MultiLevelTemplateArgumentList const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6fe2d6c)
#19 0x0000560ef9101f39 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
#20 0x0000560ef910315b 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
#21 0x0000560ef91039c2 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
#22 0x0000560ef9103f54 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+++0x67cbf54)
#23 0x0000560ef91045b2 clang::Sema::CheckInstantiatedFunctionTemplateConstraints(clang::SourceLocation, clang::FunctionDecl*, llvm::ArrayRef<clang::TemplateArgument>, clang::ConstraintSatisfaction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x67cc5b2)
#24 0x0000560ef98a9dff clang::Sema::FinishTemplateArgumentDeduction(clang::FunctionTemplateDecl*, llvm::SmallVectorImpl<clang::DeducedTemplateArgument>&, unsigned int, clang::FunctionDecl*&, clang::sema::TemplateDeductionInfo&, llvm::SmallVectorImpl<clang::Sema::OriginalCallArg> const*, bool, llvm::function_ref<bool ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6f71dff)
#25 0x0000560ef98aabfe void llvm::function_ref<void ()>::callback_fn<clang::Sema::DeduceTemplateArguments(clang::FunctionTemplateDecl*, clang::TemplateArgumentListInfo*, llvm::ArrayRef<clang::Expr*>, clang::FunctionDecl*&, clang::sema::TemplateDeductionInfo&, bool, llvm::function_ref<bool (llvm::ArrayRef<clang::QualType>)>)::'lambda1'()>(long) SemaTemplateDeduction.cpp:0:0
#26 0x0000560ef8fb2155 clang::Sema::runWithSufficientStackSpace(clang::SourceLocation, llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x667a155)
#27 0x0000560ef98b4dd3 clang::Sema::DeduceTemplateArguments(clang::FunctionTemplateDecl*, clang::TemplateArgumentListInfo*, llvm::ArrayRef<clang::Expr*>, clang::FunctionDecl*&, clang::sema::TemplateDeductionInfo&, bool, llvm::function_ref<bool (llvm::ArrayRef<clang::QualType>)>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6f7cdd3)
#28 0x0000560ef96d9a07 clang::Sema::AddMethodTemplateCandidate(clang::FunctionTemplateDecl*, clang::DeclAccessPair, clang::CXXRecordDecl*, clang::TemplateArgumentListInfo*, clang::QualType, clang::Expr::Classification, llvm::ArrayRef<clang::Expr*>, clang::OverloadCandidateSet&, bool, bool, clang::OverloadCandidateParamOrder) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6da1a07)
#29 0x0000560ef96daa33 clang::Sema::BuildCallToMemberFunction(clang::Scope*, clang::Expr*, clang::SourceLocation, llvm::MutableArrayRef<clang::Expr*>, clang::SourceLocation, clang::Expr*, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6da2a33)
#30 0x0000560ef93aa33d 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+++0x6a7233d)
#31 0x0000560ef93af9db 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+++0x6a779db)
#32 0x0000560ef8ed57b7 clang::Parser::ParsePostfixExpressionSuffix(clang::ActionResult<clang::Expr*, true>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x659d7b7)
#33 0x0000560ef8ecd847 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, bool&, clang::Parser::TypeCastState, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6595847)
#34 0x0000560ef8ed09cb clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, clang::Parser::TypeCastState, bool, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x65989cb)
#35 0x0000560ef8ed39ed clang::Parser::ParseAssignmentExpression(clang::Parser::TypeCastState) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x659b9ed)
#36 0x0000560ef8ed4ced clang::Parser::ParseExpression(clang::Parser::TypeCastState) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x659cced)
#37 0x0000560ef8f4e7de clang::Parser::ParseExprStatement(clang::Parser::ParsedStmtContext) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x66167de)
#38 0x0000560ef8f44f9a clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x660cf9a)
#39 0x0000560ef8f45e25 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x660de25)
#40 0x0000560ef8f46e1a clang::Parser::ParseCompoundStatementBody(bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x660ee1a)
#41 0x0000560ef8f4872a clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x661072a)
#42 0x0000560ef8e78b01 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6540b01)
#43 0x0000560ef8ea5750 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x656d750)
#44 0x0000560ef8e6d712 clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x6535712)
#45 0x0000560ef8e6df70 clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (.part.0) Parser.cpp:0:0
#46 0x0000560ef8e7372b clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x653b72b)
#47 0x0000560ef8e745ba clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x653c5ba)
#48 0x0000560ef8e6893a clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x653093a)
#49 0x0000560ef7c094a8 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x52d14a8)
#50 0x0000560ef749fc19 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4b67c19)
#51 0x0000560ef7426dbe clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4aeedbe)
#52 0x0000560ef75852a3 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4c4d2a3)
#53 0x0000560ef3d7fe94 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x1447e94)
#54 0x0000560ef3d78fa8 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#55 0x0000560ef7294059 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
#56 0x0000560ef681cfba llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x3ee4fba)
#57 0x0000560ef72948af clang::driver::CC1Command::Execute(llvm::ArrayRef<llvm::Optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (.part.0) Job.cpp:0:0
#58 0x0000560ef725dbd9 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x4925bd9)
#59 0x0000560ef725e65d 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+++0x492665d)
#60 0x0000560ef7267fdc clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x492ffdc)
#61 0x0000560ef3d7e2d3 clang_main(int, char**) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x14462d3)
#62 0x00007f410ccb1083 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x24083)
#63 0x0000560ef3d78bbe _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+++0x1440bbe)
clang-16: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134

[cor3ntin]

The first one works now (since Clang 13), but the second one is still an ICE. Impressively, it doesn't compile in any compiler. https://godbolt.org/z/YqE4rddMa

This is not valid (Ts is not expanded)
Crash fixed by #98496