Substantially alter the design of the Objective C type AST by introducing
ObjCObjectType, which is basically just a pair of
  one of {primitive-id, primitive-Class, user-defined @class}
with
  a list of protocols.
An ObjCObjectPointerType is therefore just a pointer which always points to
one of these types (possibly sugared).  ObjCInterfaceType is now just a kind
of ObjCObjectType which happens to not carry any protocols.

Alter a rather large number of use sites to use ObjCObjectType instead of
ObjCInterfaceType.  Store an ObjCInterfaceType as a pointer on the decl rather
than hashing them in a FoldingSet.  Remove some number of methods that are no
longer used, at least after this patch.

By simplifying ObjCObjectPointerType, we are now able to easily remove and apply
pointers to Objective-C types, which is crucial for a certain kind of ObjC++
metaprogramming common in WebKit.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@103870 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index b9aa611..5e365de 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -87,8 +87,9 @@
   }
   // Create the built-in typedef for 'id'.
   if (Context.getObjCIdType().isNull()) {
-    QualType IdT = Context.getObjCObjectPointerType(Context.ObjCBuiltinIdTy);
-    TypeSourceInfo *IdInfo = Context.getTrivialTypeSourceInfo(IdT);
+    QualType T = Context.getObjCObjectType(Context.ObjCBuiltinIdTy, 0, 0);
+    T = Context.getObjCObjectPointerType(T);
+    TypeSourceInfo *IdInfo = Context.getTrivialTypeSourceInfo(T);
     TypedefDecl *IdTypedef
       = TypedefDecl::Create(Context, CurContext, SourceLocation(),
                             &Context.Idents.get("id"), IdInfo);
@@ -98,9 +99,9 @@
   }
   // Create the built-in typedef for 'Class'.
   if (Context.getObjCClassType().isNull()) {
-    QualType ClassType
-      = Context.getObjCObjectPointerType(Context.ObjCBuiltinClassTy);
-    TypeSourceInfo *ClassInfo = Context.getTrivialTypeSourceInfo(ClassType);
+    QualType T = Context.getObjCObjectType(Context.ObjCBuiltinClassTy, 0, 0);
+    T = Context.getObjCObjectPointerType(T);
+    TypeSourceInfo *ClassInfo = Context.getTrivialTypeSourceInfo(T);
     TypedefDecl *ClassTypedef
       = TypedefDecl::Create(Context, CurContext, SourceLocation(),
                             &Context.Idents.get("Class"), ClassInfo);