gnulib-local/lib/xmalloc.c

   1 /* xmalloc.c -- malloc with out of memory checking
   2    Copyright (C) 1990-2024 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 3 of the License, or
   7    (at your option) 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, see <https://www.gnu.org/licenses/>.  */
  16
  17 #include <config.h>
  18
  19 /* Specification.  */
  20 #include "xalloc.h"
  21
  22 #include <stdlib.h>
  23
  24 #include <error.h>
  25 #include "gettext.h"
  26
  27 #define _(str) gettext (str)
  28
  29
  30 /* Exit value when the requested amount of memory is not available.
  31    The caller may set it to some other value.  */
  32 int xmalloc_exit_failure = EXIT_FAILURE;
  33
  34 void
  35 xalloc_die ()
  36 {
  37   error (xmalloc_exit_failure, 0, _("memory exhausted"));
  38   /* _Noreturn cannot be given to error, since it may return if
  39      its first argument is 0.  To help compilers understand the
  40      xalloc_die does terminate, call exit. */
  41   exit (EXIT_FAILURE);
  42 }
  43
  44 static void *
  45 fixup_null_alloc (size_t n)
  46 {
  47   void *p;
  48
  49   p = NULL;
  50   if (n == 0)
  51     p = malloc ((size_t) 1);
  52   if (p == NULL)
  53     xalloc_die ();
  54   return p;
  55 }
  56
  57 /* Allocate N bytes of memory dynamically, with error checking.  */
  58
  59 void *
  60 xmalloc (size_t n)
  61 {
  62   void *p;
  63
  64   p = malloc (n);
  65   if (p == NULL)
  66     p = fixup_null_alloc (n);
  67   return p;
  68 }
  69
  70 /* Allocate memory for NMEMB elements of SIZE bytes, with error checking.
  71    SIZE must be > 0.  */
  72
  73 void *
  74 xnmalloc (size_t nmemb, size_t size)
  75 {
  76   size_t n;
  77   void *p;
  78
  79   if (xalloc_oversized (nmemb, size))
  80     xalloc_die ();
  81   n = nmemb * size;
  82   p = malloc (n);
  83   if (p == NULL)
  84     p = fixup_null_alloc (n);
  85   return p;
  86 }
  87
  88 /* Allocate SIZE bytes of memory dynamically, with error checking,
  89    and zero it.  */
  90
  91 void *
  92 xzalloc (size_t size)
  93 {
  94   void *p;
  95
  96   p = xmalloc (size);
  97   memset (p, 0, size);
  98   return p;
  99 }
 100
 101 /* Allocate memory for N elements of S bytes, with error checking,
 102    and zero it.  */
 103
 104 void *
 105 xcalloc (size_t n, size_t s)
 106 {
 107   void *p;
 108
 109   p = calloc (n, s);
 110   if (p == NULL)
 111     p = fixup_null_alloc (n);
 112   return p;
 113 }
 114
 115 /* Change the size of an allocated block of memory P to N bytes,
 116    with error checking.
 117    If P is NULL, run xmalloc.  */
 118
 119 void *
 120 xrealloc (void *p, size_t n)
 121 {
 122   if (p == NULL)
 123     return xmalloc (n);
 124   p = realloc (p, n);
 125   if (p == NULL)
 126     p = fixup_null_alloc (n);
 127   return p;
 128 }