On Tue, Oct 10, 2017 at 03:27:11PM -0400, Dennis Dalessandro wrote: > On 10/6/2017 5:32 PM, Bart Van Assche wrote: > > Avoid that gcc 7 reports the following warning when building with W=1: > > > > warning: this statement may fall through [-Wimplicit-fallthrough=] > > > > Signed-off-by: Bart Van Assche > > Cc: Sean Hefty > > --- > > drivers/infiniband/core/cm.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c > > index d80911d4abb7..5927ee4e57ca 100644 > > --- a/drivers/infiniband/core/cm.c > > +++ b/drivers/infiniband/core/cm.c > > @@ -2808,6 +2808,7 @@ int ib_send_cm_mra(struct ib_cm_id *cm_id, > > msg_response = CM_MSG_RESPONSE_OTHER; > > break; > > } > > + /* fall through */ > > default: > > ret = -EINVAL; > > goto error1; > > > > So adding the comment is enough to make gcc shut up? Or are you just > annotating the code so it's obvious it was intentional? GCC is looking for the specific comment. --- -Wimplicit-fallthrough warns when a switch case falls through. This warning has five different levels. The compiler is able to parse a wide range of fallthrough comments, depending on the level. It also handles control-flow statements, such as ifs. It's possible to suppress the warning by either adding a fallthrough comment, or by using a null statement: __attribute__ ((fallthrough)); (C, C++), or [[fallthrough]]; (C++17), or [[gnu::fallthrough]]; (C++11/C++14). --- https://gcc.gnu.org/gcc-7/changes.html Thanks > > -Dennis > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html