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Re: [Qemu-block] [Qemu-devel] [PATCH v5] build: Work around SIZE_MAX bug
Re: [Qemu-block] [Qemu-devel] [PATCH v5] build: Work around SIZE_MAX bug in OSX headers
Tue, 11 Oct 2016 20:05:03 +0200
Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux)
Eric Blake <address@hidden> writes:
> C99 requires SIZE_MAX to be declared with the same type as the
> integral promotion of size_t, but OSX mistakenly defines it as
> an 'unsigned long long' expression even though size_t is only
> 'unsigned long'. Rather than futzing around with whether size_t
> is 32- or 64-bits wide (which would be needed if we cared about
> using SIZE_T in a #if expression), just hard-code it with a cast.
> This is not a strict C99-compliant definition, because it doesn't
> work in the preprocessor, but if we later need that, the build
> will break on Mac to inform us to improve our replacement at that
> See also https://patchwork.ozlabs.org/patch/542327/ for an
> instance where the wrong type trips us up if we don't fix it
> for good in osdep.h.
> Some versions of glibc make a similar mistake with SSIZE_MAX; the
> goal is that the approach of this patch could be copied to work
> around that problem if it ever becomes important to us.
> Signed-off-by: Eric Blake <address@hidden>
Reviewed-by: Markus Armbruster <address@hidden>