objc - fixes a crash when undefined typed property

followed by it implementation crashes when attempt
is made to access the synthesized ivar. 
// rdar://10177744


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@140432 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 4dd43c8857..31eb19e174 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -1702,7 +1702,10 @@ ExprResult Sema::ActOnIdExpression(Scope *S,
       if (ObjCIvarDecl *Ivar = R.getAsSingle<ObjCIvarDecl>()) {
         R.clear();
         ExprResult E(LookupInObjCMethod(R, S, Ivar->getIdentifier()));
-        assert(E.isInvalid() || E.get());
+        // In a hopelessly buggy code, Objective-C instance variable
+        // lookup fails and no expression will be built to reference it.
+        if (!E.isInvalid() && !E.get())
+          return ExprError();
         return move(E);
       }
     }