Ping.
On Fri, Mar 04, 2016 at 07:03:09PM +0100, Marek Polacek wrote:
> On Fri, Mar 04, 2016 at 06:41:26PM +0100, Jakub Jelinek wrote:
> > I'm ok with it for gcc6.
>
> Cool.
>
> > But IMHO you should add dg-bogus directives here.
>
> Ok, version with dg-bogus:
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2016-03-04 Marek Polacek <[email protected]>
>
> PR c/69407
> * c-common.c (resolve_overloaded_builtin): Set TREE_USED for the fetch
> operations.
>
> * gcc.dg/atomic-op-6.c: New test.
>
> diff --git gcc/c-family/c-common.c gcc/c-family/c-common.c
> index 965cf49..25afa9c 100644
> --- gcc/c-family/c-common.c
> +++ gcc/c-family/c-common.c
> @@ -11443,6 +11443,10 @@ resolve_overloaded_builtin (location_t loc, tree
> function,
> && orig_code != BUILT_IN_ATOMIC_STORE_N)
> result = sync_resolve_return (first_param, result, orig_format);
>
> + if (fetch_op)
> + /* Prevent -Wunused-value warning. */
> + TREE_USED (result) = true;
> +
> /* If new_return is set, assign function to that expr and cast the
> result to void since the generic interface returned void. */
> if (new_return)
> diff --git gcc/testsuite/gcc.dg/atomic-op-6.c
> gcc/testsuite/gcc.dg/atomic-op-6.c
> index e69de29..f88c293 100644
> --- gcc/testsuite/gcc.dg/atomic-op-6.c
> +++ gcc/testsuite/gcc.dg/atomic-op-6.c
> @@ -0,0 +1,11 @@
> +/* Test we don't generate bogus warnings. */
> +/* PR c/69407 */
> +/* { dg-do compile } */
> +/* { dg-options "-Wall -Wextra" } */
> +
> +void
> +foo (int *p, int a)
> +{
> + __atomic_fetch_add (&p, a, 0); /* { dg-bogus "value computed is not used"
> } */
> + __atomic_add_fetch (&p, a, 0); /* { dg-bogus "value computed is not used"
> } */
> +}
Marek
