Crash on invalid: ResolveSingleFunctionTemplateSpecialization (original) (raw)

Extended Description

Testcase:

template class C { public: template class Type { }; };

template class A { public: void foo() { C::template Type<2>; } };

void test() { A a; a.foo(); }

Crash stack trace:

clang: llvm-project/llvm/include/llvm/Support/Casting.h:269: typename cast_retty<X, Y *>::ret_type llvm::cast(Y *) [X = clang::FunctionTemplateDecl, Y = clang::NamedDecl]: Assertion `isa(Val) && "cast() argument of incompatible type!"' failed. PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace, preprocessed source, and associated run script. Stack dump: 0. Program arguments: ./bin/clang -cc1 -ast-dump /tmp/t1.cpp

1.  <eof> parser at end of file

2.  /tmp/t1.cpp:13:8: instantiating function definition 'A<float>::foo'

#​0 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) llvm-project/llvm/lib/Support/Unix/Signals.inc:565:11 #​1 PrintStackTraceSignalHandler(void*) llvm-project/llvm/lib/Support/Unix/Signals.inc:632:1 #​2 llvm::sys::RunSignalHandlers() llvm-project/llvm/lib/Support/Signals.cpp:70:5 #​3 SignalHandler(int) llvm-project/llvm/lib/Support/Unix/Signals.inc:407:1 #​4 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14140) #​5 raise ./signal/../sysdeps/unix/sysv/linux/raise.c:51:1 #​6 abort ./stdlib/abort.c:81:7 #​7 get_sysdep_segment_value ./intl/loadmsgcat.c:509:8 #​8 _nl_load_domain ./intl/loadmsgcat.c:970:34 #​9 (/lib/x86_64-linux-gnu/libc.so.6+0x34662) #​10 llvm::cast_retty<clang::FunctionTemplateDecl, clang::NamedDecl*>::ret_type llvm::cast<clang::FunctionTemplateDecl, clang::NamedDecl>(clang::NamedDecl*) llvm-project/llvm/include/llvm/Support/Casting.h:270:10 #​11 clang::Sema::ResolveSingleFunctionTemplateSpecialization(clang::OverloadExpr*, bool, clang::DeclAccessPair*) llvm-project/clang/lib/Sema/SemaOverload.cpp:12460:27 #​12 clang::Sema::ResolveAndFixSingleFunctionTemplateSpecialization(clang::ActionResult<clang::Expr*, true>&, bool, bool, clang::SourceRange, clang::QualType, unsigned int) llvm-project/clang/lib/Sema/SemaOverload.cpp:12525:21 #​13 clang::Sema::CheckPlaceholderExpr(clang::Expr*) llvm-project/clang/lib/Sema/SemaExpr.cpp:19272:9 #​14 clang::Sema::ActOnFinishFullExpr(clang::Expr*, clang::SourceLocation, bool, bool) llvm-project/clang/lib/Sema/SemaExprCXX.cpp:8388:16 #​15 clang::Sema::ActOnExprStmt(clang::ActionResult<clang::Expr*, true>, bool) llvm-project/clang/lib/Sema/SemaStmt.cpp:49:8 #​16 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformStmt(clang::Stmt*, clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::StmtDiscardKind) llvm-project/clang/lib/Sema/TreeTransform.h:3687:24 #​17 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformCompoundStmt(clang::CompoundStmt*, bool) llvm-project/clang/lib/Sema/TreeTransform.h:7109:38 #​18 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformCompoundStmt(clang::CompoundStmt*) llvm-project/clang/lib/Sema/TreeTransform.h:7095:23 #​19 clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::TransformStmt(clang::Stmt*, clang::TreeTransform<(anonymous namespace)::TemplateInstantiator>::StmtDiscardKind) llvm-project/build-debug/tools/clang/include/clang/AST/StmtNodes.inc:73:1 #​20 clang::Sema::SubstStmt(clang::Stmt*, clang::MultiLevelTemplateArgumentList const&) llvm-project/clang/lib/Sema/SemaTemplateInstantiate.cpp:3460:23 #​21 clang::Sema::InstantiateFunctionDefinition(clang::SourceLocation, clang::FunctionDecl*, bool, bool, bool) llvm-project/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp:4892:14 #​22 clang::Sema::PerformPendingInstantiations(bool) llvm-project/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp:6139:13 #​23 clang::Sema::ActOnEndOfTranslationUnitFragment(clang::Sema::TUFragmentKind) llvm-project/clang/lib/Sema/Sema.cpp:995:3 #​24 clang::Sema::ActOnEndOfTranslationUnit() llvm-project/clang/lib/Sema/Sema.cpp:1030:5

Looks like this is a regression, it is in trunk, but not reproducible in clang-11.0.1.