Messages in this thread | | | Date | Tue, 20 Dec 2016 11:00:56 +0100 | From | Markus Trippelsdorf <> | Subject | Re: [tip:x86/urgent] x86/tools: Fix gcc-7 warning in relocs.c |
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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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