On Fri, Mar 15, 2013 at 02:55:38PM +0000, Arnd Bergmann wrote: > I forgot to put the linux-kbuild list on Cc, that is probably the > best place to discuss this patch. > > ---------- Forwarded Message ---------- > > Subject: [PATCH] Turn off -Wmaybe-uninitialized when building with -Os > Date: Thursday 14 March 2013 > From: Arnd Bergmann <arnd@xxxxxxxx> > To: linux-arch@xxxxxxxxxxxxxxx, linux-arm-kernel@xxxxxxxxxxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx > > gcc-4.7 and higher add a lot of false positive warnings about > potential uses of uninitialized warnings, but only when optimizing > for size (-Os). This is the default when building allyesconfig, > which turns on CONFIG_CC_OPTIMIZE_FOR_SIZE. > > In order to avoid getting a lot of patches that initialize such > variables and accidentally hide real errors along the way, let's > just turn off this warning on the respective gcc versions > when building with size optimizations. The -Wmaybe-uninitialized > option was introduced in the same gcc version (4.7) that is now > causing the false positives, so there is no effect on older compilers. > > A side effect is that when building with CONFIG_CC_OPTIMIZE_FOR_SIZE, > we might now see /fewer/ warnings about possibly uninitialized > warnings than with -O2, but that is still much better than seeing > warnings known to be bogus. > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > -- > I'd like to merge this for 3.9 and also for the stable kernels, > if people agree this is a good idea. I think I replied to your previous version recently asking whether this affects real uninitialized variables too. -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
