diff options
Diffstat (limited to 'newlib/libc/include/sys/cdefs.h')
| -rw-r--r-- | newlib/libc/include/sys/cdefs.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h index e3298efaf..253258aa8 100644 --- a/newlib/libc/include/sys/cdefs.h +++ b/newlib/libc/include/sys/cdefs.h @@ -44,6 +44,10 @@ #ifndef _SYS_CDEFS_H #define _SYS_CDEFS_H +#include <sys/features.h> +#include <stddef.h> +#include <stdint.h> + #define __FBSDID(x) /* nothing */ /* * Note: the goal here is not compatibility to K&R C. Since we know that we @@ -101,6 +105,26 @@ # define __ptrvalue /* nothing */ #endif +/* + * Given the pointer x to the member m of the struct s, return + * a pointer to the containing structure. When using GCC, we first + * assign pointer x to a local variable, to check that its type is + * compatible with member m. + */ +#if __GNUC_PREREQ(3, 1) +#define __containerof(x, s, m) ({ \ + const volatile __typeof__(((s *)0)->m) *__x = (x); \ + __DEQUALIFY(s *, (const volatile char *)__x - offsetof(s, m));\ +}) +#else +#define __containerof(x, s, m) \ + __DEQUALIFY(s *, (const volatile char *)(x) - offsetof(s, m)) +#endif + +#ifndef __DEQUALIFY +#define __DEQUALIFY(type, var) ((type)(uintptr_t)(const volatile void *)(var)) +#endif + #ifdef __GNUC__ #define __strong_reference(sym,aliassym) \ extern __typeof (sym) aliassym __attribute__ ((__alias__ (#sym))); |