lib/xmalloc.c

   1 /* xmalloc.c -- malloc with out of memory checking
   2    Copyright (C) 1990, 91, 92, 93, 94 Free Software Foundation, Inc.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 2, or (at your option)
   7    any later version.
   8
   9    This program 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
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program; if not, write to the Free Software
  16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  17
  18 #ifdef HAVE_CONFIG_H
  19 #include <config.h>
  20 #endif
  21
  22 #if __STDC__
  23 #define VOID void
  24 #else
  25 #define VOID char
  26 #endif
  27
  28 #include <sys/types.h>
  29
  30 #if STDC_HEADERS
  31 #include <stdlib.h>
  32 #endif
  33
  34 #ifndef EXIT_FAILURE
  35 #define EXIT_FAILURE 1
  36 #endif
  37
  38 /* Exit value when the requested amount of memory is not available.
  39    The caller may set it to some other value.  */
  40 int xmalloc_exit_failure = EXIT_FAILURE;
  41
  42 #if __STDC__ && (HAVE_VPRINTF || HAVE_DOPRNT)
  43 void error (int, int, const char *, ...);
  44 #else
  45 void error ();
  46 #endif
  47
  48 static VOID *
  49 fixup_null_alloc (n)
  50      size_t n;
  51 {
  52   VOID *p;
  53
  54   p = 0;
  55   if (n == 0)
  56     p = malloc ((size_t) 1);
  57   if (p == 0)
  58     error (xmalloc_exit_failure, 0, "memory exhausted");
  59   return p;
  60 }
  61
  62 /* Allocate N bytes of memory dynamically, with error checking.  */
  63
  64 VOID *
  65 xmalloc (n)
  66      size_t n;
  67 {
  68   VOID *p;
  69
  70   p = malloc (n);
  71   if (p == 0)
  72     p = fixup_null_alloc (n);
  73   return p;
  74 }
  75
  76 /* Change the size of an allocated block of memory P to N bytes,
  77    with error checking.
  78    If P is NULL, run xmalloc.  */
  79
  80 VOID *
  81 xrealloc (p, n)
  82      VOID *p;
  83      size_t n;
  84 {
  85   if (p == 0)
  86     return xmalloc (n);
  87   p = realloc (p, n);
  88   if (p == 0)
  89     p = fixup_null_alloc (n);
  90   return p;
  91 }