contrib/diffutils-2.8/lib/xalloc.h

   1 /* xalloc.h -- malloc with out-of-memory checking
   2
   3    Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   4    1999, 2000, 2003 Free Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software Foundation,
  18    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  19
  20 #ifndef XALLOC_H_
  21 # define XALLOC_H_
  22
  23 # include <stddef.h>
  24
  25 # ifndef __attribute__
  26 #  if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
  27 #   define __attribute__(x)
  28 #  endif
  29 # endif
  30
  31 # ifndef ATTRIBUTE_NORETURN
  32 #  define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
  33 # endif
  34
  35 /* If this pointer is non-zero, run the specified function upon each
  36    allocation failure.  It is initialized to zero. */
  37 extern void (*xalloc_fail_func) (void);
  38
  39 /* If XALLOC_FAIL_FUNC is undefined or a function that returns, this
  40    message is output.  It is translated via gettext.
  41    Its value is "memory exhausted".  */
  42 extern char const xalloc_msg_memory_exhausted[];
  43
  44 /* This function is always triggered when memory is exhausted.  It is
  45    in charge of honoring the two previous items.  It exits with status
  46    exit_failure (defined in exitfail.h).  This is the
  47    function to call when one wants the program to die because of a
  48    memory allocation failure.  */
  49 extern void xalloc_die (void) ATTRIBUTE_NORETURN;
  50
  51 void *xmalloc (size_t s);
  52 void *xnmalloc (size_t n, size_t s);
  53 void *xzalloc (size_t s);
  54 void *xcalloc (size_t n, size_t s);
  55 void *xrealloc (void *p, size_t s);
  56 void *xnrealloc (void *p, size_t n, size_t s);
  57 void *x2realloc (void *p, size_t *pn);
  58 void *x2nrealloc (void *p, size_t *pn, size_t s);
  59 void *xclone (void const *p, size_t s);
  60 char *xstrdup (const char *str);
  61
  62 /* Return 1 if an array of N objects, each of size S, cannot exist due
  63    to size arithmetic overflow.  S must be positive and N must be
  64    nonnegative.  This is a macro, not an inline function, so that it
  65    works correctly even when SIZE_MAX < N.
  66
  67    By gnulib convention, SIZE_MAX represents overflow in size
  68    calculations, so the conservative dividend to use here is
  69    SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value.
  70    However, malloc (SIZE_MAX) fails on all known hosts where
  71    sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for
  72    exactly-SIZE_MAX allocations on such hosts; this avoids a test and
  73    branch when S is known to be 1.  */
  74 # define xalloc_oversized(n, s) \
  75     ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n))
  76
  77 /* These macros are deprecated; they will go away soon, and are retained
  78    temporarily only to ease conversion to the functions described above.  */
  79 # define CCLONE(p, n) xclone (p, (n) * sizeof *(p))
  80 # define CLONE(p) xclone (p, sizeof *(p))
  81 # define NEW(type, var) type *var = xmalloc (sizeof (type))
  82 # define XCALLOC(type, n) xcalloc (n, sizeof (type))
  83 # define XMALLOC(type, n) xnmalloc (n, sizeof (type))
  84 # define XREALLOC(p, type, n) xnrealloc (p, n, sizeof (type))
  85 # define XFREE(p) free (p)
  86
  87 #endif /* !XALLOC_H_ */