El Sat, Jul 01, 2017 at 01:11:12PM +0100 Jonathan Cameron ha dit: > On Thu, 29 Jun 2017 14:51:56 +0200 > Linus Walleij <linus.walleij@xxxxxxxxxx> wrote: > > > On Tue, Jun 27, 2017 at 2:25 AM, Matthias Kaehlcke <mka@xxxxxxxxxxxx> wrote: > > > > > Don't inflate the kernel size with data that isn't used. The conditional > > > declaration also fixes the following warning when building with clang: > > > > > > drivers/iio/magnetometer/ak8975.c:704:36: error: variable 'ak_acpi_match' > > > is not needed and will not be emitted > > > [-Werror,-Wunneeded-internal-declaration] > > > > > > Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx> > > > > Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx> > > > > Yours, > > Linus Walleij > Applied to the togreg branch of iio.git and pushed out as testing > for the autobuilders to play with it. Thanks! > I'm curious though... Can the compiler not optimize this away? > I'd always assumed the main reason for these warnings was that the > presence of unused data might represent a bug rather than it actually > making any difference to the size... clang actually optimizes it away: "variable 'ak_acpi_match' is not needed and will not be emitted", my argument about inflating the kernel size is not valid. -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
