(extend_alloca): New define. Based on stack direction it'll try to append to the previouls allocated buffer.

This commit is contained in:
Ulrich Drepper 2002-11-20 19:42:37 +00:00
parent 7f1b7f038d
commit 832737d5e2

View File

@ -1,6 +1,7 @@
#ifndef _ALLOCA_H
#include <stdlib/alloca.h>
#include <stackinfo.h>
#undef __alloca
@ -18,4 +19,31 @@ extern int __libc_alloca_cutoff (size_t size) __attribute__ ((const));
#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 extern_alloca(buf, len, newlen) \
__alloca (((len) = (newlen)))
#endif
#endif