43 lines
1.2 KiB
C
43 lines
1.2 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"
|
|
|
|
caddr_t
|
|
_sbrk (size_t incr)
|
|
{
|
|
static char *heap_end;
|
|
char *prev_heap_end;
|
|
char *sp = (char *)&sp;
|
|
|
|
if (heap_end == 0)
|
|
{
|
|
heap_end = _end;
|
|
}
|
|
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;
|
|
}
|