libgloss/mcore/sbrk.c

   1 /* sbrk.c -- allocate memory dynamically.
   2  *
   3  * Copyright (c) 1995,1996,1999 Cygnus Support
   4  *
   5  * The authors hereby grant permission to use, copy, modify, distribute,
   6  * and license this software and its documentation for any purpose, provided
   7  * that existing copyright notices are retained in all copies and that this
   8  * notice is included verbatim in any distributions. No written agreement,
   9  * license, or royalty fee is required for any of the authorized uses.
  10  * Modifications to this software may be copyrighted by their authors
  11  * and need not follow the licensing terms described here, provided that
  12  * the new terms are clearly indicated on the first page of each file where
  13  * they apply.
  14  */
  15 #include <sys/types.h>
  16 #include <sys/stat.h>
  17 #include <stdlib.h>
  18 #include "glue.h"
  19
  20 extern int _write (int, char *, int);
  21
  22 caddr_t
  23 _sbrk (size_t incr)
  24 {
  25   static char *heap_end;
  26   char *prev_heap_end;
  27   char *sp = (char *)&sp;
  28
  29   if (heap_end == 0)
  30     {
  31       heap_end = _end;
  32     }
  33   prev_heap_end = heap_end;
  34   if (heap_end > sp)
  35     {
  36       _write (1, "Heap and stack collision\n", 25);
  37 #if 0 /* Calling abort brings in the signal handling code.  */
  38       abort ();
  39 #else
  40       exit (1);
  41 #endif
  42     }
  43   heap_end += incr;
  44   return (caddr_t) prev_heap_end;
  45 }