xref: /freebsd/contrib/diff/lib/xalloc.h (revision 4fe54d7c6acb302aacc6ac18798804b26c882c13)
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_ */
88