-Warc-repeated-use-of-weak: fix a use-of-uninitialized and add a test case.

Fix-up for r165718, should get the buildbots back online.

llvm-svn: 165723

clang/lib/Sema/ScopeInfo.cpp

@@ -159,7 +159,7 @@ void FunctionScopeInfo::markSafeWeakUse(const Expr *E) {
     Uses = WeakObjectUses.find(WeakObjectProfileTy(IvarE));
   else if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
     Uses = WeakObjectUses.find(WeakObjectProfileTy(DRE));
-  else if (const ObjCMessageExpr *MsgE = dyn_cast<ObjCMessageExpr>(MsgE)) {
+  else if (const ObjCMessageExpr *MsgE = dyn_cast<ObjCMessageExpr>(E)) {
     Uses = WeakObjectUses.end();
     if (const ObjCMethodDecl *MD = MsgE->getMethodDecl()) {
       if (const ObjCPropertyDecl *Prop = MD->findPropertyDecl()) {

clang/test/SemaObjC/arc-repeated-weak.mm

@@ -181,6 +181,18 @@ void assignToStrongWithCasts(Test *a) {
   }
 }
 
+void assignToStrongWithMessages(Test *a) {
+  if (condition()) {
+    id val = [a weakProp]; // no-warning
+    (void)val;
+  } else {
+    id val;
+    val = [a weakProp]; // no-warning
+    (void)val;
+  }
+}
+
+
 void assignAfterRead(Test *a) {
   // Special exception for a single read before any writes.
   if (!a.weakProp) // no-warning