| Issue |
204059
|
| Summary |
[clang][Sema] Crash in MultiLevelTemplateArgumentList with dependent member decltype using Completion
|
| Labels |
clang
|
| Assignees |
|
| Reporter |
hongtaihu
|
This input is generated by a fuzzer.
```cxx
template <class T, class U>
auto k(T t) -> decltype (t.U::template B<>::MEM);
void t() {
k( C() );
}
```
```
-fsyntax-only -Xclang -code-completion-at=example.cpp:4:6
```
It seems that this input will trigger crash since clang8. However, since clang 20, the assertion changed.
Before clang20, it shows:
```
`Index < TemplateArgumentLists[getNumLevels() - Depth - 1].Args.size()' failed.
```
Since clang20, it shows:
```
Assertion `getKind() == Type && "Unexpected kind"' failed.
```
I am not sure whether it's related to https://github.com/llvm/llvm-project/issues/162125 because before clang20. the stacktrace looks similar to it.
Current stacktrace:
```
<source>:4:3: error: use of undeclared identifier 'C'
4 | k(C()<U+0000>);
| ^
clang++: /root/llvm-project/clang/include/clang/Sema/Template.h:156: const clang::TemplateArgument& clang::MultiLevelTemplateArgumentList::operator()(unsigned int, unsigned int) const: Assertion `Index < TemplateArgumentLists[getNumLevels() - Depth - 1].Args.size()' 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-19.1.0/bin/clang++ -g -o /app/output.s -mllvm --x86-asm-syntax=intel -fno-verbose-asm -S --gcc-toolchain=/opt/compiler-explorer/gcc-14.2.0 -fcolor-diagnostics -fno-crash-diagnostics -fsyntax-only -Xclang -code-completion-at=example.cpp:4:6 <source>
1. <eof> parser at end of file
2. <source>:3:10: parsing function body 't'
3. <source>:3:10: in compound statement ('{}')
#0 0x0000000003ae9978 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x3ae9978)
#1 0x0000000003ae766c llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x3ae766c)
#2 0x0000000003a308f8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
#3 0x00007b264f845330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330)
#4 0x00007b264f89eb2c pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x9eb2c)
#5 0x00007b264f84527e raise (/lib/x86_64-linux-gnu/libc.so.6+0x4527e)
#6 0x00007b264f8288ff abort (/lib/x86_64-linux-gnu/libc.so.6+0x288ff)
#7 0x00007b264f82881b (/lib/x86_64-linux-gnu/libc.so.6+0x2881b)
#8 0x00007b264f83b517 (/lib/x86_64-linux-gnu/libc.so.6+0x3b517)
#9 0x000000000718a02b clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformCXXDependentScopeMemberExpr(clang::CXXDependentScopeMemberExpr*) SemaTemplateInstantiate.cpp:0:0
#10 0x000000000715bab6 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformExpr(clang::Expr*) SemaTemplateInstantiate.cpp:0:0
#11 0x000000000716c48c clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformType(clang::TypeLocBuilder&, clang::TypeLoc) SemaTemplateInstantiate.cpp:0:0
#12 0x0000000007194987 clang::Sema::SubstFunctionDeclType(clang::TypeSourceInfo*, clang::MultiLevelTemplateArgumentList const&, clang::SourceLocation, clang::DeclarationName, clang::CXXRecordDecl*, clang::Qualifiers, bool) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x7194987)
#13 0x00000000071cdd5e clang::TemplateDeclInstantiator::SubstFunctionType(clang::FunctionDecl*, llvm::SmallVectorImpl<clang::ParmVarDecl*>&) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x71cdd5e)
#14 0x00000000072232ea clang::TemplateDeclInstantiator::VisitFunctionDecl(clang::FunctionDecl*, clang::TemplateParameterList*, clang::TemplateDeclInstantiator::RewriteKind) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x72232ea)
#15 0x0000000007227394 void llvm::function_ref<void ()>::callback_fn<clang::Sema::SubstDecl(clang::Decl*, clang::DeclContext*, clang::MultiLevelTemplateArgumentList const&)::'lambda'()>(long) SemaTemplateInstantiateDecl.cpp:0:0
#16 0x000000000663df41 clang::Sema::runWithSufficientStackSpace(clang::SourceLocation, llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x663df41)
#17 0x00000000071cdb1a clang::Sema::SubstDecl(clang::Decl*, clang::DeclContext*, clang::MultiLevelTemplateArgumentList const&) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x71cdb1a)
#18 0x000000000709a53e 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-19.1.0/bin/clang+++0x709a53e)
#19 0x000000000709ca5a void llvm::function_ref<void ()>::callback_fn<clang::Sema::DeduceTemplateArguments(clang::FunctionTemplateDecl*, clang::TemplateArgumentListInfo*, llvm::ArrayRef<clang::Expr*>, clang::FunctionDecl*&, clang::sema::TemplateDeductionInfo&, bool, bool, clang::QualType, clang::Expr::Classification, llvm::function_ref<bool (llvm::ArrayRef<clang::QualType>)>)::'lambda1'()>(long) SemaTemplateDeduction.cpp:0:0
#20 0x000000000663df41 clang::Sema::runWithSufficientStackSpace(clang::SourceLocation, llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x663df41)
#21 0x00000000070a78c2 clang::Sema::DeduceTemplateArguments(clang::FunctionTemplateDecl*, clang::TemplateArgumentListInfo*, llvm::ArrayRef<clang::Expr*>, clang::FunctionDecl*&, clang::sema::TemplateDeductionInfo&, bool, bool, clang::QualType, clang::Expr::Classification, llvm::function_ref<bool (llvm::ArrayRef<clang::QualType>)>) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x70a78c2)
#22 0x0000000006eba5e8 clang::Sema::AddTemplateOverloadCandidate(clang::FunctionTemplateDecl*, clang::DeclAccessPair, clang::TemplateArgumentListInfo*, llvm::ArrayRef<clang::Expr*>, clang::OverloadCandidateSet&, bool, bool, bool, clang::CallExpr::ADLCallKind, clang::OverloadCandidateParamOrder, bool) (.constprop.1) SemaOverload.cpp:0:0
#23 0x0000000006ebadeb AddOverloadedCallCandidate(clang::Sema&, clang::DeclAccessPair, clang::TemplateArgumentListInfo*, llvm::ArrayRef<clang::Expr*>, clang::OverloadCandidateSet&, bool, bool) SemaOverload.cpp:0:0
#24 0x0000000006ebb0d9 clang::Sema::AddOverloadedCallCandidates(clang::UnresolvedLookupExpr*, llvm::ArrayRef<clang::Expr*>, clang::OverloadCandidateSet&, bool) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x6ebb0d9)
#25 0x000000000677c359 clang::SemaCodeCompletion::ProduceCallSignatureHelp(clang::Expr*, llvm::ArrayRef<clang::Expr*>, clang::SourceLocation) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x677c359)
#26 0x000000000654dee2 clang::Parser::ParsePostfixExpressionSuffix(clang::ActionResult<clang::Expr*, true>) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x654dee2)
#27 0x0000000006546e21 clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, bool&, clang::Parser::TypeCastState, bool, bool*) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x6546e21)
#28 0x0000000006548f7a clang::Parser::ParseCastExpression(clang::Parser::CastParseKind, bool, clang::Parser::TypeCastState, bool, bool*) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x6548f7a)
#29 0x0000000006549119 clang::Parser::ParseAssignmentExpression(clang::Parser::TypeCastState) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x6549119)
#30 0x000000000654d9a9 clang::Parser::ParseExpression(clang::Parser::TypeCastState) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x654d9a9)
#31 0x00000000065ce309 clang::Parser::ParseExprStatement(clang::Parser::ParsedStmtContext) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x65ce309)
#32 0x00000000065c4d02 clang::Parser::ParseStatementOrDeclarationAfterAttributes(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*, clang::ParsedAttributes&, clang::ParsedAttributes&) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x65c4d02)
#33 0x00000000065c5cc0 clang::Parser::ParseStatementOrDeclaration(llvm::SmallVector<clang::Stmt*, 32u>&, clang::Parser::ParsedStmtContext, clang::SourceLocation*) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x65c5cc0)
#34 0x00000000065c6ba9 clang::Parser::ParseCompoundStatementBody(bool) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x65c6ba9)
#35 0x00000000065c837a clang::Parser::ParseFunctionStatementBody(clang::Decl*, clang::Parser::ParseScope&) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x65c837a)
#36 0x00000000064dd6c3 clang::Parser::ParseFunctionDefinition(clang::ParsingDeclarator&, clang::Parser::ParsedTemplateInfo const&, clang::Parser::LateParsedAttrList*) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x64dd6c3)
#37 0x0000000006512708 clang::Parser::ParseDeclGroup(clang::ParsingDeclSpec&, clang::DeclaratorContext, clang::ParsedAttributes&, clang::Parser::ParsedTemplateInfo&, clang::SourceLocation*, clang::Parser::ForRangeInit*) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x6512708)
#38 0x00000000064d115e clang::Parser::ParseDeclOrFunctionDefInternal(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec&, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x64d115e)
#39 0x00000000064d190e clang::Parser::ParseDeclarationOrFunctionDefinition(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*, clang::AccessSpecifier) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x64d190e)
#40 0x00000000064d8077 clang::Parser::ParseExternalDeclaration(clang::ParsedAttributes&, clang::ParsedAttributes&, clang::ParsingDeclSpec*) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x64d8077)
#41 0x00000000064d8f6f clang::Parser::ParseTopLevelDecl(clang::OpaquePtr<clang::DeclGroupRef>&, clang::Sema::ModuleImportState&) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x64d8f6f)
#42 0x00000000064cc33a clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x64cc33a)
#43 0x0000000004684f59 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x4684f59)
#44 0x0000000004609f8e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x4609f8e)
#45 0x000000000476e2be clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x476e2be)
#46 0x0000000000c82b7f cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0xc82b7f)
#47 0x0000000000c7bcda ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#48 0x000000000443cba9 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
#49 0x0000000003a30da4 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x3a30da4)
#50 0x000000000443d19f 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
#51 0x0000000004402c05 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x4402c05)
#52 0x000000000440366d clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x440366d)
#53 0x000000000440b075 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0x440b075)
#54 0x0000000000c7fe95 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0xc7fe95)
#55 0x0000000000b547a4 main (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0xb547a4)
#56 0x00007b264f82a1ca (/lib/x86_64-linux-gnu/libc.so.6+0x2a1ca)
#57 0x00007b264f82a28b __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2a28b)
#58 0x0000000000c7b78e _start (/opt/compiler-explorer/clang-assertions-19.1.0/bin/clang+++0xc7b78e)
clang++: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134
```
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