On Fri, May 15, 2015 at 9:09 AM, Szabolcs Nagy <szabolcs.n...@arm.com> wrote: > > > On 15/05/15 16:05, H.J. Lu wrote: >> On Mon, Apr 20, 2015 at 12:00 PM, Szabolcs Nagy <szabolcs.n...@arm.com> >> wrote: >>> The posix_memalign declaration is incompatible with musl for C++, >>> because of the exception specification. It also pollutes the >>> namespace and lacks protection against a potential macro definition >>> that is allowed by POSIX. The fix avoids source level namespace >>> pollution but retains the dependency on the posix_memalign extern >>> libc symbol. >>> >>> The fix is ugly, but it is not possible to correctly redeclare a >>> libc function in a public gcc header for C++. >>> >>> >>> gcc/Changelog: >>> >>> 2015-04-16 Szabolcs Nagy <szabolcs.n...@arm.com> >>> >>> * config/i386/pmm_malloc.h (posix_memalign): Renamed to ... >>> (__gcc_posix_memalign): This. Use posix_memalign as extern >>> symbol only. >> >> What does this try to achieve? Do you have a testcase which >> fails before and passes with this patch? > > if posix_memalign is defined in stdlib.h according to posix then > the exception specifier used in mm_malloc.h is incompatible: > > $ echo "#include <mm_malloc.h>" | ./x86_64-linux-musl-g++ -pedantic -c -xc++ > -D_POSIX_C_SOURCE=200809L - > In file included from <stdin>:1:0: > /data/cross/x86_64-linux-musl/lib/gcc/x86_64-linux-musl/6.0.0/include/mm_malloc.h:34:64: > error: declaration of 'int posix_memalign(void**, size_t, > size_t) throw ()' has a different exception specifier > extern "C" int posix_memalign (void **, size_t, size_t) throw () > ^ > In file included from > /data/cross/x86_64-linux-musl/lib/gcc/x86_64-linux-musl/6.0.0/include/mm_malloc.h:27:0, > from <stdin>:1: > /data/cross/x86_64-linux-musl/x86_64-linux-musl/include/stdlib.h:98:5: error: > from previous declaration 'int posix_memalign(void**, size_t, size_t)' > int posix_memalign (void **, size_t, size_t); > ^ > > however it seems without -pedantic there is no error anymore, > the code is accepted even in standard conforming mode. > (it used to be an error that could not be silenced). > > this means the patch is no longer critical for musl support. >
2 more comments: 1. You need a tecase, independent of MUSL. 2. Please replace __gcc_posix_memalign with _mm_posix_memalign. -- H.J.
