I work currently on a better FreeBSD compatibility for Newlib. For
RTEMS we use the network, USB, SD/MMC stacks from FreeBSD. It would be
nice to use <sys/types.h>, etc. from Newlib directly to compile FreeBSD
user and kernel space files.
Various FreeBSD source and header files need a typedef __size_t via
<sys/_types.h>. Unfortunately the GCC provided <stddef.h> uses
#if (defined (__FreeBSD__) && (__FreeBSD__ >= 5)) \
|| defined(__DragonFly__) \
|| defined(__FreeBSD_kernel__)
/* __size_t is a typedef on FreeBSD 5, must not trash it. */
#elif defined (__VMS__)
/* __size_t is also a typedef on VMS. */
#else
#define __size_t
#endif
and therefore defines __size_t to nothing on Newlib targets which would
trash a __size_t typedef. There exists no Newlib builtin define which
we could add here. As a workaround I include <stddef.h> before
<sys/_types.h> in <sys/types.h> and undefine __size_t in <sys/_types.h>.
This works fine so far, but breaks if someone includes <stddef.h> after
<sys/_types.h> the first time.
This patch would address this issue, but I do not know which other
issues it generates.
gcc/ChangeLog
2016-04-15 Sebastian Huber <sebastian.hu...@embedded-brains.de>
* ginclude/stddef.h (__size_t): Define to __SIZE_TYPE__.
---
gcc/ginclude/stddef.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/ginclude/stddef.h b/gcc/ginclude/stddef.h
index d711530..8c2e22e 100644
--- a/gcc/ginclude/stddef.h
+++ b/gcc/ginclude/stddef.h
@@ -207,7 +207,7 @@ typedef __PTRDIFF_TYPE__ ptrdiff_t;
#elif defined (__VMS__)
/* __size_t is also a typedef on VMS. */
#else
-#define __size_t
+#define __size_t __SIZE_TYPE__
#endif
#ifndef __SIZE_TYPE__
#define __SIZE_TYPE__ long unsigned int
--
1.8.4.5
