[cfe-dev] Questions about CXXRecordDecl

[Johannes Schaub (litb)]

Alexander MacDonald wrote:

> Hi, I'm writing a small clang plugin to inspect a codebase I work on and
> perform various custom semantic analyses. I've figured out most of what I
> need but I've run into a couple of small problems:
> 
> Given a CXXRecordDecl which represents an implicitly instantiated template
> class (mydecl->getTemplateSpecializationKind() ==
> TSK_ImplicitInstantiation). I want to find the original unspecialized
> CXXRecordDecl / QualType. mydecl->getDescribedClassTemplate() is returning
> null, perhaps there's some functionality in Sema I should be using
> instead?
> 

It sounds like you want

    mydecl->getInstantiatedFrom()

(cast it to ClassTemplateSpecializationDecl first). If it was implicitly 
instantiated from a primary class template (instead of a partial 
specialization), you may need to call getTemplatedDecl() on the resulting 
pointer to get the CXXRecordDecl of the template. 

Assuming mydecl is a "A<int>", mydecl->getDescribedClassTemplate() would 
return true for the CXXRecordDecl of "A<T>". The class A<int> is not 
templated, so has no class template is describes.

This is just the result of my doxygen checkup. I've no experience with clang 
code, but it makes sense :)