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SubjectRe: [tip:x86/urgent] x86/tools: Fix gcc-7 warning in relocs.c
On 2016.12.20 at 01:30 -0800, H. Peter Anvin wrote:
> I'd strongly prefer a non-data-dependent solution, specifically adding
> at the top of sort_relocs():
>
> if (!r->count)
> return;
>
> However, by my reading of the C and POSIX standards, this is a gcc
> error: qsort() should do nothing if the count is zero.

No, it is invoking undefined behavior.

Notice the nonnull attribute in /usr/include/stdlib.h:

739 /* Sort NMEMB elements of BASE, of SIZE bytes each,
740 using COMPAR to perform the comparisons. */
741 extern void qsort (void *__base, size_t __nmemb, size_t __size,
742 __compar_fn_t __compar) __nonnull ((1, 4));

But feel free to revert my patch and add your solution.

--
Markus

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