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 <pola...@redhat.com> > > 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