[notmuch] [PATCH 1/2] * avoid gcc 4.4.1 compiler warnings due to ignored write return values
Jed Brown
jed at 59A2.org
Mon Nov 23 08:38:42 PST 2009
On Mon, 23 Nov 2009 18:14:12 +0200, Dirk-Jan Binnema <djcb.bulk at gmail.com> wrote:
> Did you try it with -O2? Without optimizations many of the warnings are not
> issued.
Yes,
$ cat > foo.c
#include <stdlib.h>
#include <unistd.h>
int main()
{
malloc(5);
write(2,0,10);
return 0;
}
$ gcc -static -std=c89 -O0 -Wall -Wextra -pedantic -o foo foo.c
$ objdump -d -M intel foo |grep -A12 '<main>'
00000000004002a4 <main>:
4002a4: 55 push rbp
4002a5: 48 89 e5 mov rbp,rsp
4002a8: bf 05 00 00 00 mov edi,0x5
4002ad: e8 6e 61 00 00 call 406420 <__libc_malloc>
4002b2: ba 0a 00 00 00 mov edx,0xa
4002b7: be 00 00 00 00 mov esi,0x0
4002bc: bf 02 00 00 00 mov edi,0x2
4002c1: e8 ea a0 00 00 call 40a3b0 <__libc_write>
4002c6: b8 00 00 00 00 mov eax,0x0
4002cb: c9 leave
4002cc: c3 ret
4002cd: 90 nop
$ gcc -v
Using built-in specs.
Target: x86_64-unknown-linux-gnu
Configured with: ../configure --prefix=/usr --enable-shared --enable-languages=c,c++,fortran,objc,obj-c++,ada --enable-threads=posix --mandir=/usr/share/man --infodir=/usr/share/info --enable-__cxa_atexit --disable-multilib --libdir=/usr/lib --libexecdir=/usr/lib --enable-clocale=gnu --disable-libstdcxx-pch --with-tune=generic
Thread model: posix
gcc version 4.4.2 (GCC)
$ uname -a
Linux kunyang 2.6.31-ARCH #1 SMP PREEMPT Tue Nov 10 19:01:40 CET 2009 x86_64 Intel(R) Core(TM)2 Duo CPU P8700 @ 2.53GHz GenuineIntel GNU/Linux
Seems fishy.
Jed
More information about the notmuch
mailing list