[cfe-dev] Type exploration in clang AST

[John McCall]

On Dec 13, 2010, at 4:03 AM, Olivier wrote:

> Hi,
> 
> I'm trying to figure out how to extract information from the Type classes 
> hierarchy but I'm bumping into a few problems.
> 
> Given a template instantiation TI - that would be represented by a 
> clang::TemplateSpecializationType node - I'm trying to determine if any of the 
> template arguments of TI are used as a member or a base class of TI.
> 
> But I can't seem to figure out how to get that information from a 
> clang::TemplateSpecializationType.
> 
> 
> void process( clang::TemplateSpecializationType const *pType )
> {
>  // Get the associated template declaration.
>  clang::TemplateDecl const *pDecl
>    = pType->getTemplateName().getAsTemplateDecl();
> 
>  if(pDecl)
>  {
>    // Get the templated record associated to the template specialization.
>    clang::CXXRecordDecl const *pRecD
>      = cast<clang::CXXRecordDecl>(pDecl->getTemplatedDecl());
> 
>    // Get a pointer to the instantiation arguments array.
>    clang::TemplateArgument const *pArgs = pType->getArgs();
> 
>    // Get the size of the instantiation arguments array.
>    unsigned nbArgs = pType->getNumArgs();
>  }
> }
> 
> How with this information can I now get the complete types of all base classes 
> and members of the type represented by 'pType' ?

TST->getAsCXXRecordDecl().  If that's null, the type refers to an unknown
specialization;  otherwise, you can ask the decl if it's complete, and if it is
then you can walk over the members and base types.  Be aware that a type
can be a known specialization and still be dependent, so the direct (and
indirect) base classes may still be dependent, unresolved types.

John.