On linux, when the build variable USE_NED_ALLOCATOR is set, gcc issues the following warnings: In file included from compat/nedmalloc/nedmalloc.c:63: .../malloc.c.h: In function 'mmap_resize': .../malloc.c.h:3762: warning: implicit declaration of function 'mremap' .../malloc.c.h: In function 'sys_trim': .../malloc.c.h:4195: warning: comparison between pointer and integer The warnings are caused by the <sys/mman.h> header not enabling the (conditional) declaration of the mremap() function. The declaration can be enabled by defining the _GNU_SOURCE symbol prior to including certain system header files. In particular, it may not be sufficient to simply define _GNU_SOURCE just prior to including the <sys/mman.h> header. (e.g. defining the symbol after including <sys/types.h> will be completely ineffective.) In order to suppress the warnings, we define the _GNU_SOURCE symbol at the start of the malloc.c.h header file. Signed-off-by: Ramsay Jones <ramsay@xxxxxxxxxxxxxxxxxxx> --- compat/nedmalloc/malloc.c.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/compat/nedmalloc/malloc.c.h b/compat/nedmalloc/malloc.c.h index fdcca82..5a44dea 100644 --- a/compat/nedmalloc/malloc.c.h +++ b/compat/nedmalloc/malloc.c.h @@ -484,6 +484,10 @@ MAX_RELEASE_CHECK_RATE default: 4095 unless not HAVE_MMAP #define DLMALLOC_VERSION 20804 #endif /* DLMALLOC_VERSION */ +#if defined(linux) +#define _GNU_SOURCE 1 +#endif + #ifndef WIN32 #ifdef _WIN32 #define WIN32 1 -- 1.8.2 -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html