glibc/include/alloca.h
2011-01-13 14:01:56 -05:00

64 lines
1.7 KiB
C

#ifndef _ALLOCA_H
#include <stdlib/alloca.h>
#include <stackinfo.h>
#undef __alloca
/* Now define the internal interfaces. */
extern void *__alloca (size_t __size);
#ifdef __GNUC__
# define __alloca(size) __builtin_alloca (size)
#endif /* GCC. */
extern int __libc_use_alloca (size_t size) __attribute__ ((const));
extern int __libc_alloca_cutoff (size_t size) __attribute__ ((const));
libc_hidden_proto (__libc_alloca_cutoff)
#define __MAX_ALLOCA_CUTOFF 65536
#include <allocalim.h>
#if _STACK_GROWS_DOWN
# define extend_alloca(buf, len, newlen) \
(__typeof (buf)) ({ size_t __newlen = (newlen); \
char *__newbuf = __alloca (__newlen); \
if (__newbuf + __newlen == (char *) buf) \
len += __newlen; \
else \
len = __newlen; \
__newbuf; })
#elif _STACK_GROWS_UP
# define extend_alloca(buf, len, newlen) \
(__typeof (buf)) ({ size_t __newlen = (newlen); \
char *__newbuf = __alloca (__newlen); \
char *__buf = (buf); \
if (__buf + __newlen == __newbuf) \
{ \
len += __newlen; \
__newbuf = __buf; \
} \
else \
len = __newlen; \
__newbuf; })
#else
# define extend_alloca(buf, len, newlen) \
__alloca (((len) = (newlen)))
#endif
#if defined stackinfo_get_sp && defined stackinfo_sub_sp
# define alloca_account(size, avar) \
({ void *old__ = stackinfo_get_sp (); \
void *m__ = __alloca (size); \
avar += stackinfo_sub_sp (old__); \
m__; })
#else
# define alloca_account(size, avar) \
({ size_t s__ = (size); \
avar += s__; \
__alloca (s__); })
#endif
#endif