Skip NonNull sema checks in unevaluated contexts.

Summary:
Currently when a function annotated with __attribute__((nonnull)) is called in an unevaluated context with a null argument a -Wnonnull warning is emitted. 
This warning seems like a false positive unless the call expression is potentially evaluated. Change this behavior so that the non-null warnings use DiagRuntimeBehavior so they wont emit when they won't be evaluated.

Reviewers: majnemer, rsmith

Subscribers: mclow.lists, cfe-commits

Differential Revision: http://reviews.llvm.org/D13408

llvm-svn: 249787

1 files changed, 3 insertions, 0 deletions

diff --git a/clang/test/Sema/non-null-warning.c b/clang/test/Sema/non-null-warning.c
index 024ef1eca66..7dfa3900cbb 100644
--- a/clang/test/Sema/non-null-warning.c
+++ b/clang/test/Sema/non-null-warning.c
@@ -37,6 +37,9 @@ int * ret_nonnull() {
   return 0; // expected-warning {{null returned from function that requires a non-null return value}}
 }
 
+#define SAFE_CALL(X) if (X) foo(X)
 int main () {
   foo(0); // expected-warning {{null passed to a callee that requires a non-null argument}}
+  (void)sizeof(foo(0)); // expect no diagnostic in unevaluated context.
+  SAFE_CALL(0); // expect no diagnostic for unreachable code.
 }