[cfe-dev] Problems in clang/AST/ASTConsumer.h

[Paolo Bolzoni]

did you use -fno-rtti?


On Wed, 10 Dec 2008 12:07:56 +0100
Simone Pellegrini <spellegrini at dps.uibk.ac.at> wrote:
> Hi,
> I'm extending the ASTConsumer class to make some custom analysis on the 
> Syntax tree created by clang in the following way:
> 
> class MyASTConsumer: public ASTConsumer {
>     ...
> }
> 
> when I try to compile my program using the g++ compiler (I've used both 
> the gcc 3.4.6 and gcc 4.3.2). I get the following error:
> 
> build/main.o(.gnu.linkonce.r._ZTI13MyASTConsumer+0x10): undefined 
> reference to `typeinfo for clang::ASTConsumer'
> collect2: ld returned 1 exit status
> 
> Apparently the error is caused by the empty virtual definition of 
> ASTConsumer methods:
>  virtual ~ASTConsumer();
>  virtual void InitializeTU(TranslationUnit& TU) ;
> 
> changing this declaration (in the ASTConsumer.h file) into:
>  virtual ~ASTConsumer() {}
>  virtual void InitializeTU(TranslationUnit& TU) {}
> or:
>  virtual ~ASTConsumer() = 0;
>  virtual void InitializeTU(TranslationUnit& TU) = 0;
> 
> fixes the problem for me! Of course in the second problem I have to 
> provide an implementation for both the methods in my class.
> 
> I hope it helps,
> greetings Simone