Teach DeclContext how to find the primary declaration for any TagDecl

even when we are still defining the TagDecl. This is required so that
qualified name lookup of a class name within its definition works (see
the new bits in test/SemaCXX/qualified-id-lookup.cpp).

As part of this, move the nested redefinition checking code into
ActOnTag. This gives us diagnostics earlier (when we try to perform
the nested redefinition, rather than when we try to complete the 2nd
definition) and removes some code duplication.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62386 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 29 deletions

diff --git a/lib/AST/DeclBase.cpp b/lib/AST/DeclBase.cpp
index 860a65a1e3..28656873ab 100644
--- a/lib/AST/DeclBase.cpp
+++ b/lib/AST/DeclBase.cpp
@@ -442,37 +442,15 @@ DeclContext *DeclContext::getPrimaryContext() {
     return static_cast<NamespaceDecl*>(this)->getOriginalNamespace();
 
   case Decl::Enum:
-#if 0
-    // FIXME: See the comment for CXXRecord, below.
-    // The declaration associated with the enumeration type is our
-    // primary context.
-    return Context.getTypeDeclType(static_cast<EnumDecl*>(this))
-             ->getAsEnumType()->getDecl();
-#else
-    return this;
-#endif
-
   case Decl::Record:
-  case Decl::CXXRecord: {
-    // The declaration associated with the type is be our primary
-    // context. 
-#if 0
-    // FIXME: This is what we expect to do. However, it doesn't work
-    // because ASTContext::setTagDefinition changes the result of
-    // Context.getTypeDeclType, meaning that our "primary" declaration
-    // of a RecordDecl/CXXRecordDecl will change, and we won't be able
-    // to find any values inserted into the earlier "primary"
-    // declaration. We need better tracking of redeclarations and
-    // definitions.
-    QualType Type = Context.getTypeDeclType(static_cast<RecordDecl*>(this));
-    return Type->getAsRecordType()->getDecl();
-#else
-    // FIXME: This hack will work for now, because the declaration we
-    // create when we're defining the record is the one we'll use as
-    // the definition later.
+  case Decl::CXXRecord:
+    // If this is a tag type that has a definition or is currently
+    // being defined, that definition is our primary context.
+    if (TagType *TagT = cast_or_null<TagType>(cast<TagDecl>(this)->TypeForDecl))
+      if (TagT->isBeingDefined() || 
+          (TagT->getDecl() && TagT->getDecl()->isDefinition()))
+        return TagT->getDecl();
     return this;
-#endif
-  }
 
   case Decl::ObjCMethod:
     return this;