-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.

llvm-svn: 165629

2 files changed, 12 insertions, 1 deletions

diff --git a/clang/lib/Sema/ScopeInfo.cpp b/clang/lib/Sema/ScopeInfo.cpp
index 7a9d917a025..76f967d588b 100644
--- a/clang/lib/Sema/ScopeInfo.cpp
+++ b/clang/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/clang/test/SemaObjC/arc-repeated-weak.mm b/clang/test/SemaObjC/arc-repeated-weak.mm
index 90ba75f6efd..1c6578ef131 100644
--- a/clang/test/SemaObjC/arc-repeated-weak.mm
+++ b/clang/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