From c694e693b098ca624a65815f2481be3223385107 Mon Sep 17 00:00:00 2001
From: Fariborz Jahanian <fjahanian@apple.com>
Date: Tue, 14 Oct 2014 20:27:05 +0000
Subject: [PATCH] Patch to warn on interger overflow in presence of implicit
 casts. Reviewed by Reid Kleckner. rdar://18405357

llvm-svn: 219712
---
 clang/lib/Sema/SemaChecking.cpp | 4 ++--
 clang/test/Sema/switch-1.c      | 5 +++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index 58c626351f9e..a98b87544a6b 100644
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -6754,8 +6754,8 @@ void Sema::CheckImplicitConversions(Expr *E, SourceLocation CC) {
 /// Diagnose when expression is an integer constant expression and its evaluation
 /// results in integer overflow
 void Sema::CheckForIntOverflow (Expr *E) {
-  if (isa<BinaryOperator>(E->IgnoreParens()))
-    E->EvaluateForOverflow(Context);
+  if (isa<BinaryOperator>(E->IgnoreParenCasts()))
+    E->IgnoreParenCasts()->EvaluateForOverflow(Context);
 }
 
 namespace {
diff --git a/clang/test/Sema/switch-1.c b/clang/test/Sema/switch-1.c
index ce1e7dc9433f..5191c92e714d 100644
--- a/clang/test/Sema/switch-1.c
+++ b/clang/test/Sema/switch-1.c
@@ -20,3 +20,8 @@ int f(int i) {
   return (i, 65537) * 65537; // expected-warning {{overflow in expression; result is 131073 with type 'int'}} \
 			     // expected-warning {{expression result unused}}
 }
+
+// rdar://18405357
+unsigned long long l = 65536 * 65536; // expected-warning {{overflow in expression; result is 0 with type 'int'}}
+unsigned long long l2 = 65536 * (unsigned)65536;
+unsigned long long l3 = 65536 * 65536ULL;