Implemenent objective-c's NSObject attribute as a way of ddeclaraing c-type
objects as an objective-c object.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@62197 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index 759ef09..f444c71 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -578,6 +578,22 @@
   d->addAttr(new ObjCGCAttr(type));
 }
 
+static void HandleObjCNSObject(Decl *d, const AttributeList &Attr, Sema &S) {
+  if (Attr.getNumArgs() != 0) {
+    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 1;
+    return;
+  }
+  if (TypedefDecl *TD = dyn_cast<TypedefDecl>(d)) {
+    QualType T = TD->getUnderlyingType();
+    if (!T->isPointerType() ||
+        !T->getAsPointerType()->getPointeeType()->isRecordType()) {
+      S.Diag(TD->getLocation(), diag::err_nsobject_attribute);
+      return;
+    }
+  }
+  d->addAttr(new ObjCNSObjectAttr);
+}
+
 static void HandleBlocksAttr(Decl *d, const AttributeList &Attr, Sema &S) {
   if (!Attr.getParameterName()) {    
     S.Diag(Attr.getLoc(), diag::err_attribute_argument_n_not_string)
@@ -1228,6 +1244,7 @@
     HandleTransparentUnionAttr(D, Attr, S);
     break;
   case AttributeList::AT_objc_gc:     HandleObjCGCAttr    (D, Attr, S); break;
+  case AttributeList::AT_nsobject:    HandleObjCNSObject  (D, Attr, S); break;
   case AttributeList::AT_blocks:      HandleBlocksAttr    (D, Attr, S); break;
   case AttributeList::AT_sentinel:    HandleSentinelAttr  (D, Attr, S); break;
   case AttributeList::AT_const:       HandleConstAttr     (D, Attr, S); break;