Gcc 9 adds the flag to default warnings and this produces a lot of
warnings that don't seem to be harmful as we know the address is
aligned, but this could be hidden in the function call chain.
It's still available under W=1.
Issue: #180
Signed-off-by: David Sterba <dsterba@suse.com>
Under most case, we are just using 'int' for 'unsigned int', and doesn't
care about the sign.
The -Wsign-compare warning is causing tons of false alerts. Suppressing
it makes W=1 less noisy so we can focus on real problems, while still
allowing it in W=3 build.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When using gcc8 + glibc 2.28.5 compiles utils.c, it complains as below:
utils.c:852:45: warning: '%s' directive output may be truncated writing
up to 4095 bytes into a region of size 4084 [-Wformat-truncation=]
snprintf(path, sizeof(path), "/dev/mapper/%s", name);
^~ ~~~~
In file included from /usr/include/stdio.h:873,
from utils.c:20:
/usr/include/bits/stdio2.h:67:10: note: '__builtin___snprintf_chk'
output between 13 and 4108 bytes into a destination of size 4096
return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
__bos (__s), __fmt, __va_arg_pack ());
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This isn't a type of warning we care about, particularly when calling
snprintf() we expect string to be truncated.
Use the GCC option -Wno-format-truncation to disable this for default
build and W=1 build, while still keeping it for W=2 and W=3 builds.
Signed-off-by: Su Yanjun <suyj.fnst@cn.fujitsu.com>
[ Use cc-disable-warning to fix the not working CFLAGS setting in configure.ac ]
[ Keep the warning in W=2/W=3 build ]
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We imported cc-option but forgot to import cc-disable-warning.
Fixes: b556a992c3 ("btrfs-progs: build: allow to build with various compiler warnings")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Copied from linux kernel, 'make W=1' will build with various additional
warnings turned on. There are 3 levels, combinations are possible. The
build is quite noisy, not all warnings need to be fixed.
A specific warning can be turned on by 'make EXTRA_CFLAGS=-Wsomething'.
Signed-off-by: David Sterba <dsterba@suse.com>
David Sterba
Qu Wenruo
Su Yanjun