newlib-cygwin/libgloss/pru/sbrk.c

47 lines
1.3 KiB
C

/* sbrk.c -- allocate memory dynamically.
*
* Copyright (c) 1995,1996,1999 Cygnus Support
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice is included verbatim in any distributions. No written agreement,
* license, or royalty fee is required for any of the authorized uses.
* Modifications to this software may be copyrighted by their authors
* and need not follow the licensing terms described here, provided that
* the new terms are clearly indicated on the first page of each file where
* they apply.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include "glue.h"
extern char _heap_start[];
extern void exit (int) __attribute ((__noreturn__));
extern int _write (int, char *, int);
caddr_t
_sbrk (size_t incr)
{
static char *heap_end;
char *prev_heap_end;
char *sp = (char *)&sp;
if (heap_end == 0)
{
heap_end = _heap_start;
}
prev_heap_end = heap_end;
if (heap_end > sp)
{
_write (1, "Heap and stack collision\n", 25);
#if 0 /* Calling abort brings in the signal handling code. */
abort ();
#else
exit (1);
#endif
}
heap_end += incr;
return (caddr_t) prev_heap_end;
}