This patch includes a conceptually simple, but very intrusive/pervasive change. 

The idea is to segregate Objective-C "object" pointers from general C pointers (utilizing the recently added ObjCObjectPointerType). The fun starts in Sema::GetTypeForDeclarator(), where "SomeInterface *" is now represented by a single AST node (rather than a PointerType whose Pointee is an ObjCInterfaceType). Since a significant amount of code assumed ObjC object pointers where based on C pointers/structs, this patch is very tedious. It should also explain why it is hard to accomplish this in smaller, self-contained patches.

This patch does most of the "heavy lifting" related to moving from PointerType->ObjCObjectPointerType. It doesn't include all potential "cleanups". The good news is additional cleanups can be done later (some are noted in the code). This patch is so large that I didn't want to include any changes that are purely aesthetic.

By making the ObjC types truly built-in, they are much easier to work with (and require fewer "hacks"). For example, there is no need for ASTContext::isObjCIdStructType() or ASTContext::isObjCClassStructType()! We believe this change (and the follow-up cleanups) will pay dividends over time. 

Given the amount of code change, I do expect some fallout from this change (though it does pass all of the clang tests). If you notice any problems, please let us know asap! Thanks.

llvm-svn: 75314
diff --git a/clang/lib/Sema/Sema.h b/clang/lib/Sema/Sema.h
index 58fccc3..10ea514 100644
--- a/clang/lib/Sema/Sema.h
+++ b/clang/lib/Sema/Sema.h
@@ -3037,6 +3037,8 @@
   // Helper function for CheckAssignmentConstraints (C99 6.5.16.1p1)
   AssignConvertType CheckPointerTypesForAssignment(QualType lhsType, 
                                                    QualType rhsType);
+  AssignConvertType CheckPointeeTypesForAssignment(QualType lhsType, 
+                                                   QualType rhsType);
                                                    
   // Helper function for CheckAssignmentConstraints involving two
   // block pointer types.