Start emitting ElaboratedTypes in C++ mode.  Support the effort in various
ways:  remove elab types during desugaring, enhance pretty-printing to allow
tags to be suppressed without suppressing scopes, look through elab types
when associating a typedef name with an anonymous record type.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@81065 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index 755cc22..b41902c 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -52,6 +52,10 @@
         // If the desugared type is a vector type, we don't want to expand it,
         // it will turn into an attribute mess. People want their "vec4".
         !isa<VectorType>(DesugaredTy) &&
+
+        // Don't aka just because we saw an elaborated type.
+        (!isa<ElaboratedType>(Ty) ||
+         cast<ElaboratedType>(Ty)->getUnderlyingType() != DesugaredTy) &&
       
         // Don't desugar magic Objective-C types.
         Ty.getUnqualifiedType() != Context.getObjCIdType() &&
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index e929b5f..9809ea5 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -3893,7 +3893,7 @@
                                            D.getIdentifier(), 
                                            T);
   
-  if (TagType *TT = dyn_cast<TagType>(T)) {
+  if (const TagType *TT = T->getAs<TagType>()) {
     TagDecl *TD = TT->getDecl();
     
     // If the TagDecl that the TypedefDecl points to is an anonymous decl
diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 80cdcd5..b6db829 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -195,6 +195,13 @@
            "Can't handle qualifiers on typedef names yet!");
     // TypeQuals handled by caller.
     Result = Context.getTypeDeclType(cast<TypeDecl>(D));
+
+    // In C++, make an ElaboratedType.
+    if (getLangOptions().CPlusPlus) {
+      TagDecl::TagKind Tag
+        = TagDecl::getTagKindForTypeSpec(DS.getTypeSpecType());
+      Result = Context.getElaboratedType(Result, Tag);
+    }
     
     if (D->isInvalidDecl())
       isInvalid = true;