On Wed, Jun 11, 2014 at 2:28 PM, Paolo Carlini <paolo.carl...@oracle.com> wrote:
> Hi,
>
> On 05/22/2014 09:02 PM, Jakub Jelinek wrote:
>>
>> In file included from
>> ../../../../trunk/libsanitizer/asan/asan_interceptors.cc:147:0:
>>
>> ../../../../trunk/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:
>> In function ‘int __interceptor_accept4(int, void*, unsigned int*,
>> int)’:
>>
>> ../../../../trunk/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:1821:12:
>> warning: ‘addrlen0’ may be used uninitialized in this function
>> [-Wmaybe-uninitialized]
>> unsigned addrlen0;
>> ^
>>
>> ../../../../trunk/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:
>> In function ‘int __interceptor_accept(int, void*, unsigned int*)’:
>>
>> ../../../../trunk/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc:1799:12:
>> warning: ‘addrlen0’ may be used uninitialized in this function
>> [-Wmaybe-uninitialized]
>> unsigned addrlen0;
>> ^
>> That sounds like a false positive warning:
>> unsigned addrlen0;
>> if (addrlen) {
>> COMMON_INTERCEPTOR_READ_RANGE(ctx, addrlen, sizeof(*addrlen));
>> addrlen0 = *addrlen;
>> }
>> int fd2 = REAL(accept4)(fd, addr, addrlen, f);
>> if (fd2 >= 0) {
>> if (fd >= 0) COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, fd2);
>> if (addr && addrlen)
>> COMMON_INTERCEPTOR_WRITE_RANGE(ctx, addr, Min(*addrlen, addrlen0));
>> }
>> (unless the COMMON_INTERCEPTOR* macros do too weird stuff), wonder why the
>> predicate aware uninit doesn't handle this.
>
> By the way, I'm still seeing the above. Maybe a maintainer can have a look,
> double check it's just a false positive a shut it up somehow?
I've "fixed" this in upstream trunk:
http://llvm.org/viewvc/llvm-project?view=revision&revision=211008
This will get into GCC with the next merge; or feel free to cherry pick.
Meanwhile, this still smells like a bug in GCC's -Wmaybe-uninitialized
-- I'd encourage you to at least file a bug on it.
--kcc
>
> Thanks!
> Paolo.
