[cfe-dev] clang::CXXRecordDecl::data __assert_fail. Clang problem, or bug in my VisitCXXRecordDecl() implementation?

[Yang Chen]

Peeter Joot wrote:
> I've got an AST visitor defined with the following method:
>
> class MyASTVisitor : public RecursiveASTVisitor<MyASTVisitor>
> {
>
> ...
>    bool VisitCXXRecordDecl( CXXRecordDecl* r )
>    {
>       cout << "VisitCXXRecordDecl:: CLASS: " << r->getName().str() << 
> endl ;
>
>       for ( CXXRecordDecl::base_class_iterator b = r->bases_begin(), e 
> = r->bases_end() ;
>             b != e ; ++b )
>       {
>          CXXBaseSpecifier & a = *b ;
>
>          const QualType & q = a.getType() ;
>
>          cout << r->getName().str() << " : " << q.getAsString() << endl ;
>       }
>
>       return true ;
>    }
>
> This is triggering the following assertion:
>
> classvisitor: 
> /home/peeterj/clang/optimized/include/clang/AST/DeclCXX.h:522: struct 
> DefinitionData &clang::CXXRecordDecl::data(): Assertion 
> `DefinitionData && "queried property of class with no definition"' failed.
>
> Program received signal SIGABRT, Aborted.
> 0x00007ffff6f20645 in raise () from /lib64/libc.so.6
> (gdb) where
> #0  0x00007ffff6f20645 in raise () from /lib64/libc.so.6
> #1  0x00007ffff6f21c33 in abort () from /lib64/libc.so.6
> #2  0x00007ffff6f19329 in __assert_fail () from /lib64/libc.so.6
> #3  0x0000000000467b85 in clang::CXXRecordDecl::data (this=0x155f740) 
> at /home/peeterj/clang/optimized/include/clang/AST/DeclCXX.h:522
> #4  0x0000000000467ade in clang::CXXRecordDecl::bases_begin 
> (this=0x155f740) at 
> /home/peeterj/clang/optimized/include/clang/AST/DeclCXX.h:640
> #5  0x00000000004681af in MyASTVisitor::VisitCXXRecordDecl 
> (this=0x7fffffff8f70, r=0x155f740) at classvisitor.cpp:61
> #6  0x0000000000467ffa in 
> clang::RecursiveASTVisitor<MyASTVisitor>::WalkUpFromCXXRecordDecl 
> (this=0x7fffffff8f70, D=0x155f740)
>     at /home/peeterj/clang/optimized/include/clang/AST/DeclNodes.inc:207
> #7  0x000000000041f13f in 
> clang::RecursiveASTVisitor<MyASTVisitor>::TraverseCXXRecordDecl 
> (this=0x7fffffff8f70, D=0x155f740)
>     at 
> /home/peeterj/clang/optimized/include/clang/AST/RecursiveASTVisitor.h:1586
> #8  0x000000000041d0f9 in 
> clang::RecursiveASTVisitor<MyASTVisitor>::TraverseDecl 
> (this=0x7fffffff8f70, D=0x155f740)
>     at /home/peeterj/clang/optimized/include/clang/AST/DeclNodes.inc:207
> #9  0x000000000041c7f4 in MyASTConsumer::HandleTopLevelDecl 
> (this=0x7fffffff8f60, DR=...) at classvisitor.cpp:122
> #10 0x0000000000612c75 in clang::ParseAST(clang::Sema&, bool, bool) ()
> #11 0x0000000000612f70 in clang::ParseAST(clang::Preprocessor&, 
> clang::ASTConsumer*, clang::ASTContext&, bool, 
> clang::TranslationUnitKind, clang::CodeCompleteConsumer*, bool) ()
> #12 0x0000000000419b31 in main (argc=77, argv=0x7fffffffd008) at 
> classvisitor.cpp:314
> (gdb) frame 5
> #5  0x00000000004681af in MyASTVisitor::VisitCXXRecordDecl 
> (this=0x7fffffff8f70, r=0x155f740) at classvisitor.cpp:61
> 61            for ( CXXRecordDecl::base_class_iterator b = 
> r->bases_begin(), e = r->bases_end() ;
> (gdb) p *r
> $1 = {<clang::RecordDecl> = {<clang::TagDecl> = {<clang::TypeDecl> = 
> {<clang::NamedDecl> = {<clang::Decl> = {_vptr$Decl = 0x132a350,
>             NextInContextAndBits = {Value = 0}, DeclCtx = {Val = 
> {Value = 20481056}}, Loc = {ID = 1203259}, DeclKind = 25, InvalidDecl = 0,
>             HasAttrs = 0, Implicit = 0, Used = 0, Referenced = 0, 
> Access = 3, FromASTFile = 0, Hidden = 0, IdentifierNamespace = 6,
>             HasCachedLinkage = 0, CachedLinkage = 0}, Name = {Ptr = 
> 22363280}}, TypeForDecl = 0x155f7d0, LocStart = {
>           ID = 1203253}}, <clang::DeclContext> = {DeclKind = 25, 
> ExternalLexicalStorage = 0, ExternalVisibleStorage = 0, LookupPtr = 
> {Value = 0},
>         FirstDecl = 0x0, LastDecl = 0x0}, 
> <clang::Redeclarable<clang::TagDecl>> = {RedeclLink = 
> {NextAndIsPrevious = {Value = 22411074}}},
>       TagDeclKind = 3, IsCompleteDefinition = false, IsBeingDefined = 
> false, IsEmbeddedInDeclarator = false, IsFreeStanding = true,
>       NumPositiveBits = 0, NumNegativeBits = 0, IsScoped = false, 
> IsScopedUsingClassTag = false, IsFixed = false, RBraceLoc = {ID = 0},
>       TypedefNameDeclOrQualifier = {Val = {Value = 0}}}, 
> HasFlexibleArrayMember = false, AnonymousStructOrUnion = false, 
> HasObjectMember = false,
>     LoadedFieldsFromExternalStorage = false}, DefinitionData = 0x0, 
> TemplateOrInstantiation = {Val = {Value = 0}}}
>
> Is it appropriate for me to be attempting to iterate over the base 
> classes in this CXXRecordDecl() override, or is this a bug in the AST 
> visitor library?

If I am correct, you can iterate over the base classes only if this 
CXXRecordDecl is a definition.

- Yang

>
> $ ~/clang/optimized/bin/clang --version
>
> clang version 3.3 (trunk 169628)
> Target: x86_64-unknown-linux-gnu
> Thread model: posix
>
> -- 
> Peeter
> ------------------------------------------------------------------------
>
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