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| author | Vineet Gupta <vgupta@synopsys.com> | 2016-03-18 11:28:01 +0300 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2016-03-18 13:52:36 +0300 |
| commit | a69fe1a2c9b2bd35046cb8f4e61337825cef9239 (patch) | |
| tree | ddc1955039d71a002a5f727ab798fdc3012548fb /arch/arc | |
| parent | 667a490bdb6e27db0887d2ca515b907d6aa87118 (diff) | |
| download | linux-a69fe1a2c9b2bd35046cb8f4e61337825cef9239.tar.xz | |
ARC: build: Turn off -Wmaybe-uninitialized for ARC gcc 4.8
linux-next has been reporting gazillion warnings for ARC build and
I finally decided to take a bite:
http://kisskb.ellerman.id.au/kisskb/buildresult/12638735/
Most of the them are due to -Wmaybe-uninitialized
| ../kernel/sysctl.c: In function '__do_proc_doulongvec_minmax':
| ../kernel/sysctl.c:1928:12: warning: 'p' may be used uninitialized in this function [-Wmaybe-uninitialized]
| ret = tmp - *buf;
| ^
| ../kernel/sysctl.c:2342:29: note: 'p' was declared here
| char *kbuf = NULL, *p;
| ^
| ...
| ...
Cursory look at code seemed fine and a definite gcc false positive in say
kernel/sysctl.c
Mystery was why only for ARC (and not with ARM linaro toolchain based
off same gcc 4.8). Turns out that -O3 (default for ARC) triggers these
and if I enable -O3 for ARM kernel build, I see the same splat.
I initially wanted to disable this only for gcc 4.8, but Arnd reported
it is seen even on gcc 6.0 for ARM with -O3. Thus better to disable
this independent of gcc version.
Cc: Claudiu Zissulescu <Claudiu.Zissulescu@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-kbuild@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc')
| -rw-r--r-- | arch/arc/Makefile | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/arc/Makefile b/arch/arc/Makefile index fed12f39d8ce..def69e347b2d 100644 --- a/arch/arc/Makefile +++ b/arch/arc/Makefile @@ -76,7 +76,9 @@ endif ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE # Generic build system uses -O2, we want -O3 # Note: No need to add to cflags-y as that happens anyways -ARCH_CFLAGS += -O3 +# +# Disable the false maybe-uninitialized warings gcc spits out at -O3 +ARCH_CFLAGS += -O3 $(call cc-disable-warning,maybe-uninitialized,) endif # small data is default for elf32 tool-chain. If not usable, disable it |