Allow front-end 'isa' access on object's of type 'id'.
Enhance test case to cover 'isa' access on interface types (clang produces an error, GCC produces a warning).

Still need back-end CodeGen for ObjCIsaExpr.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@76979 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Frontend/PCHReaderStmt.cpp b/lib/Frontend/PCHReaderStmt.cpp
index 5681b67..16c0e79 100644
--- a/lib/Frontend/PCHReaderStmt.cpp
+++ b/lib/Frontend/PCHReaderStmt.cpp
@@ -104,6 +104,7 @@
     unsigned VisitObjCKVCRefExpr(ObjCKVCRefExpr *E);
     unsigned VisitObjCMessageExpr(ObjCMessageExpr *E);
     unsigned VisitObjCSuperExpr(ObjCSuperExpr *E);
+    unsigned VisitObjCIsaExpr(ObjCIsaExpr *E);
     
     unsigned VisitObjCForCollectionStmt(ObjCForCollectionStmt *);
     unsigned VisitObjCAtCatchStmt(ObjCAtCatchStmt *);
@@ -448,6 +449,14 @@
   return 1;
 }
 
+unsigned PCHStmtReader::VisitObjCIsaExpr(ObjCIsaExpr *E) {
+  VisitExpr(E);
+  E->setBase(cast<Expr>(StmtStack.back()));
+  E->setIsaMemberLoc(SourceLocation::getFromRawEncoding(Record[Idx++]));
+  E->setArrow(Record[Idx++]);
+  return 1;
+}
+
 unsigned PCHStmtReader::VisitCastExpr(CastExpr *E) {
   VisitExpr(E);
   E->setSubExpr(cast<Expr>(StmtStack.back()));
@@ -1106,6 +1115,9 @@
     case pch::EXPR_OBJC_SUPER_EXPR:
       S = new (Context) ObjCSuperExpr(Empty);
       break;
+    case pch::EXPR_OBJC_ISA:
+      S = new (Context) ObjCIsaExpr(Empty);
+      break;
     case pch::STMT_OBJC_FOR_COLLECTION:
       S = new (Context) ObjCForCollectionStmt(Empty);
       break;