libgloss/v850/sbrk.c

   1 #include <_ansi.h>
   2 #include <sys/types.h>
   3 #include <sys/stat.h>
   4 #include "sys/syscall.h"
   5 #include <stdlib.h>
   6
   7 extern int _write (int, char *, int);
   8
   9 caddr_t
  10 _sbrk (int incr)
  11 {
  12   extern char   heap_start[];           /* Defined by the linker script. */
  13   static char * heap_end = NULL;
  14   char *        prev_heap_end;
  15   char *        sp = (char *) & sp;
  16
  17   if (heap_end == NULL)
  18     heap_end = heap_start;
  19
  20   prev_heap_end = heap_end;
  21
  22   if (heap_end + incr > sp)
  23     {
  24 #define MESSAGE "Heap and stack collision\n"
  25       _write (1, MESSAGE, sizeof MESSAGE);
  26       abort ();
  27     }
  28
  29   heap_end += incr;
  30
  31   return (caddr_t) prev_heap_end;
  32 }