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 #else
  33 VOID *malloc ();
  34 VOID *realloc ();
  35 void free ();
  36 #endif
  37
  38 #ifndef EXIT_FAILURE
  39 #define EXIT_FAILURE 1
  40 #endif
  41
  42 /* Exit value when the requested amount of memory is not available.
  43    The caller may set it to some other value.  */
  44 int xmalloc_exit_failure = EXIT_FAILURE;
  45
  46 #if __STDC__ && (HAVE_VPRINTF || HAVE_DOPRNT)
  47 void error (int, int, const char *, ...);
  48 #else
  49 void error ();
  50 #endif
  51
  52 static VOID *
  53 fixup_null_alloc (n)
  54      size_t n;
  55 {
  56   VOID *p;
  57
  58   p = 0;
  59   if (n == 0)
  60     p = malloc ((size_t) 1);
  61   if (p == 0)
  62     error (xmalloc_exit_failure, 0, "memory exhausted");
  63   return p;
  64 }
  65
  66 /* Allocate N bytes of memory dynamically, with error checking.  */
  67
  68 VOID *
  69 xmalloc (n)
  70      size_t n;
  71 {
  72   VOID *p;
  73
  74   p = malloc (n);
  75   if (p == 0)
  76     p = fixup_null_alloc (n);
  77   return p;
  78 }
  79
  80 /* Change the size of an allocated block of memory P to N bytes,
  81    with error checking.
  82    If P is NULL, run xmalloc.  */
  83
  84 VOID *
  85 xrealloc (p, n)
  86      VOID *p;
  87      size_t n;
  88 {
  89   if (p == 0)
  90     return xmalloc (n);
  91   p = realloc (p, n);
  92   if (p == 0)
  93     p = fixup_null_alloc (n);
  94   return p;
  95 }