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H A DMakefilea1c48bb160f8368ea9668a1ff98513631fa0d87a Tue May 27 02:54:12 CDT 2014 Geert Uytterhoeven <geert@linux-m68k.org> Makefile: Fix unrecognized cross-compiler command line options

On architectures that setup CROSS_COMPILE in their arch/*/Makefile
(arc, blackfin, m68k, mips, parisc, score, sh, tile, unicore32, xtensa),
cc-option and cc-disable-warning may check against the wrong compiler,
causing errors like

cc1: error: unrecognized command line option "-Wno-maybe-uninitialized"

if the host gcc supports a compiler option, while the cross compiler
doesn't support that option.

Move all logic using cc-option or cc-disable-warning below the inclusion
of the arch's Makefile to fix this.

Introduced by
- commit e74fc973b6e531fef1fce8b101ffff05ecfb774c ("Turn off
-Wmaybe-uninitialized when building with -Os"),
- commit 61163efae02040f66a95c8ed17f4407951ba58fa ("kbuild: LLVMLinux:
Add Kbuild support for building kernel with Clang").

As -Wno-maybe-uninitialized requires a quite recent gcc (gcc 4.6.3 on
Ubuntu 12.04 LTS doesn't support it), this only showed up recently (gcc
4.8.2 on Ubuntu 14.04 LTS does support it).

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>
e74fc973b6e531fef1fce8b101ffff05ecfb774c Fri Feb 15 14:23:58 CST 2013 Arnd Bergmann <arnd@arndb.de> Turn off -Wmaybe-uninitialized when building with -Os

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@arndb.de>