malloc/morecore.c

   1 /* Copyright (C) 1991,92,93,94,95,97,2002,2004 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #ifndef _MALLOC_INTERNAL
  20 #define _MALLOC_INTERNAL
  21 #include <malloc.h>
  22 #endif
  23
  24 #ifndef __GNU_LIBRARY__
  25 #define __sbrk  sbrk
  26 #endif
  27
  28 #ifdef __GNU_LIBRARY__
  29 /* It is best not to declare this and cast its result on foreign operating
  30    systems with potentially hostile include files.  */
  31
  32 #include <stddef.h>
  33 #include <stdlib.h>
  34 extern __malloc_ptr_t __sbrk (ptrdiff_t increment) __THROW;
  35 libc_hidden_proto (__sbrk)
  36 #endif
  37
  38 #ifndef NULL
  39 #define NULL 0
  40 #endif
  41
  42 /* Allocate INCREMENT more bytes of data space,
  43    and return the start of data space, or NULL on errors.
  44    If INCREMENT is negative, shrink data space.  */
  45 __malloc_ptr_t
  46 __default_morecore (increment)
  47      __malloc_ptrdiff_t increment;
  48 {
  49   __malloc_ptr_t result = (__malloc_ptr_t) __sbrk (increment);
  50   if (result == (__malloc_ptr_t) -1)
  51     return NULL;
  52   return result;
  53 }
  54 libc_hidden_def (__default_morecore)