Re: [PATCH -mm] sys_semctl gcc 4.1 warning fix

Daniel Walker
2006-05-10T19:49:40Z

There's no code increase when you init something to itself . I could
convert all the instance of the warning, that I've investigated, to a
system like this . I think it would be a benefit so we could clearly
identify any new warnings added over time, and quiet the ones we know
aren't real errors .

However, from all the responses I'd imagine a patch like this wouldn't
get accepted ..

Daniel

On Wed, 2006-05-10 at 15:20 -0400, Steven Rostedt wrote:
> Someone emailed me the bug report for gcc:
>
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=5035
>
>
> And in this, it showed the trick to initialize self to turn off that
> warning.
>
> Would it be OK to define a macro like:
>
> #ifdef CONFIG_SHOW_ALL_UNINIT_WARNINGS
> # define init_self(x) x
> #else
> # define init_self(x) x = x
> #endif
>
> Such that we can at least look at the places of bogus uninitialized
> warnings and do something like:
>
> Index: ipc/sem.c
> ===================================================================
> --- ipc/sem.c (revision 796)
> +++ ipc/sem.c (working copy)
> @@ -809,7 +809,7 @@
> {
> struct sem_array *sma;
> int err;
> - struct sem_setbuf setbuf;
> + struct sem_setbuf init_self(setbuf);
> struct kern_ipc_perm *ipcp;
>
> if(cmd == IPC_SET) {
>
>
> Seems to work. And if you want to make sure that a place doesn't need it
> anymore, use -Winit-self and have a script to do a full make once with
> CONFIG_SHOW_ALL_UNINIT_WARNINGS and once with -Winit-self, and make sure
> that all the -Winit-self warnings are in the
> CONFIG_SHOW_ALL_UNINIT_WARNINGS. Otherwise the init_self isn't needed
> anymore.
>
> -- Steve
>
>