-Warc-repeated-use-of-weak: look through explicit casts on assigned values.

Reading from a weak property, casting the result, and assigning to a
strong pointer should still be considered safe.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@165629 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 12 insertions, 1 deletions

diff --git a/lib/Sema/ScopeInfo.cpp b/lib/Sema/ScopeInfo.cpp
index 7a9d917a02..76f967d588 100644
--- a/lib/Sema/ScopeInfo.cpp
+++ b/lib/Sema/ScopeInfo.cpp
@@ -115,7 +115,7 @@ FunctionScopeInfo::WeakObjectProfileTy::WeakObjectProfileTy(
 }
 
 void FunctionScopeInfo::markSafeWeakUse(const Expr *E) {
-  E = E->IgnoreParenImpCasts();
+  E = E->IgnoreParenCasts();
 
   if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) {
     markSafeWeakUse(POE->getSyntacticForm());
diff --git a/test/SemaObjC/arc-repeated-weak.mm b/test/SemaObjC/arc-repeated-weak.mm
index 90ba75f6ef..1c6578ef13 100644
--- a/test/SemaObjC/arc-repeated-weak.mm
+++ b/test/SemaObjC/arc-repeated-weak.mm
@@ -147,6 +147,17 @@ void testBlock(Test *a) {
   });
 }
 
+void assignToStrongWithCasts(Test *a) {
+  if (condition()) {
+    Test *val = (Test *)a.weakProp; // no-warning
+    (void)val;
+  } else {
+    id val;
+    val = (Test *)a.weakProp; // no-warning
+    (void)val;
+  }
+}
+
 
 @interface Test (Methods)
 @end