Re: tools/perf compile error: ignoring return value of 'read', declaredwith attribute warn_unused_result

From: Kevin Winchester
Date: Thu Jul 02 2009 - 19:49:47 EST


Ingo Molnar wrote:
> * Kevin Winchester <kjwinchester@xxxxxxxxx> wrote:
>
>> CC builtin-stat.o
>> cc1: warnings being treated as errors
>> builtin-stat.c: In function 'run_perf_stat':
>> builtin-stat.c:243: error: ignoring return value of 'read', declared with attribute warn_unused_result
>> builtin-stat.c:256: error: ignoring return value of 'read', declared with attribute warn_unused_result
>> make: *** [builtin-stat.o] Error 1
>>
>> Apparently my version of gcc and/or glibc do not agree with -Werror. Would the fix be as simple as:
>>
>> if *read(go_pipe[0], &buf, 1) < 0) {
>> perror("Failed to read go_pipe.");
>> exit(1);
>> }
>>
>> ?
>
> Yeah, that's Ubuntu doing some must-check-warnings via headers,
> right?
>
> Frederic fixed a bug there yesterday - mind checking the latest
> perfcounters code at:
>
> http://people.redhat.com/mingo/tip.git/README
>
> ?
>

It's Gentoo, actually, but likely the same issue. I checked tip/master and it does not show the problem.

Thanks for taking the time to look into it,

--
Kevin Winchester
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