posix_memalign definitely exists on OSX, but we're not defining HAVE_POSIX_MEMALIGN for some reason.

It looks like AC_CHECK_FUNCS generally doesn't work on OSX now. clang is too clever. #line 14154 "configure" /* System header to define __stub macros and hopefully few prototypes, which can conflict with char posix_memalign(); below. */ #include <assert.h> /* Override any gcc2 internal prototype to avoid an error. */ #ifdef __cplusplus extern "C" #endif /* We use char because int might match the return type of a gcc2 builtin and then its argument prototype would still apply. */ char posix_memalign(); int main() { /* The GNU C library defines this for functions which it implements to always fail with ENOSYS. Some functions are actually named something starting with __ and the normal name is an alias. */ #if defined (__stub_posix_memalign) || defined (__stub___posix_memalign) choke me #else posix_memalign(); #endif ; return 0; } mozilla@macmini 1% gcc posix_memalign_conftest.C ~ configure:14163:6: error: functions that differ only in their return type cannot be overloaded char posix_memalign(); ^ /usr/include/stdlib.h:156:7: note: previous declaration is here int posix_memalign(void **, size_t, size_t) __OSX_AVAILABLE_STARTIN... ^ configure:14173:1: error: no matching function for call to 'posix_memalign' posix_memalign(); ^~~~~~~~~~~~~~ /usr/include/stdlib.h:156:7: note: candidate function not viable: requires 3 arguments, but 0 were provided int posix_memalign(void **, size_t, size_t) __OSX_AVAILABLE_STARTIN... ^ 2 errors generated.

https://tbpl.mozilla.org/php/getParsedLog.php?id=34605513&full=1&branch=try checking for posix_memalign... yes

And a fixup. https://hg.mozilla.org/integration/mozilla-inbound/rev/532299d1368f

(In reply to Mike Hommey [:glandium] from comment #5) > And a fixup. > https://hg.mozilla.org/integration/mozilla-inbound/rev/532299d1368f This avoids non clobber builds picking the old (wrong) cached value

https://hg.mozilla.org/mozilla-central/rev/95c7723f382f https://hg.mozilla.org/mozilla-central/rev/532299d1368f