1 /* xalloc.h -- malloc with out-of-memory checking
3 Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4 1999, 2000, 2003, 2004 Free Software Foundation, Inc.
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)
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.
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
31 # ifndef __attribute__
32 # if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 8) || __STRICT_ANSI__
33 # define __attribute__(x)
37 # ifndef ATTRIBUTE_NORETURN
38 # define ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
41 /* This function is always triggered when memory is exhausted.
42 It must be defined by the application, either explicitly
43 or by using gnulib's xalloc-die module. This is the
44 function to call when one wants the program to die because of a
45 memory allocation failure. */
46 extern void xalloc_die (void) ATTRIBUTE_NORETURN;
48 void *xmalloc (size_t s);
49 void *xnmalloc (size_t n, size_t s);
50 void *xzalloc (size_t s);
51 void *xcalloc (size_t n, size_t s);
52 void *xrealloc (void *p, size_t s);
53 void *xnrealloc (void *p, size_t n, size_t s);
54 void *x2realloc (void *p, size_t *pn);
55 void *x2nrealloc (void *p, size_t *pn, size_t s);
56 void *xmemdup (void const *p, size_t s);
57 char *xstrdup (char const *str);
59 /* Return 1 if an array of N objects, each of size S, cannot exist due
60 to size arithmetic overflow. S must be positive and N must be
61 nonnegative. This is a macro, not an inline function, so that it
62 works correctly even when SIZE_MAX < N.
64 By gnulib convention, SIZE_MAX represents overflow in size
65 calculations, so the conservative dividend to use here is
66 SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value.
67 However, malloc (SIZE_MAX) fails on all known hosts where
68 sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for
69 exactly-SIZE_MAX allocations on such hosts; this avoids a test and
70 branch when S is known to be 1. */
71 # define xalloc_oversized(n, s) \
72 ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n))
74 /* In the following macros, T must be an elementary or structure/union or
75 typedef'ed type, or a pointer to such a type. To apply one of the
76 following macros to a function pointer or array type, you need to typedef
77 it first and use the typedef name. */
79 /* Allocate an object of type T dynamically, with error checking. */
80 /* extern T *XMALLOC (typename T); */
82 ((T *) xmalloc (sizeof (T)))
84 /* Allocate memory for NMEMB elements of type T, with error checking. */
85 /* extern T *XNMALLOC (size_t nmemb, typename T); */
87 /* xnmalloc performs a division and multiplication by sizeof (T). Arrange to
88 perform the division at compile-time and the multiplication with a factor
89 known at compile-time. */
90 # define XNMALLOC(N,T) \
91 ((T *) (sizeof (T) == 1 \
93 : xnboundedmalloc(N, (size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / sizeof (T), sizeof (T))))
95 xnboundedmalloc (size_t n, size_t bound, size_t s)
99 return xmalloc (n * s);
102 # define XNMALLOC(N,T) \
103 ((T *) (sizeof (T) == 1 ? xmalloc (N) : xnmalloc (N, sizeof (T))))
106 /* Allocate an object of type T dynamically, with error checking,
108 /* extern T *XZALLOC (typename T); */
110 ((T *) xzalloc (sizeof (T)))
112 /* Allocate memory for NMEMB elements of type T, with error checking,
114 /* extern T *XCALLOC (size_t nmemb, typename T); */
115 #define XCALLOC(N,T) \
116 ((T *) xcalloc (N, sizeof (T)))
118 /* Return a pointer to a new buffer of N bytes. This is like xmalloc,
119 except it returns char *.
120 xcharalloc (N) is equivalent to XNMALLOC (N, char). */
122 xcharalloc (size_t n)
124 return (char *) xmalloc (n);
130 /* C++ does not allow conversions from void * to other pointer types
131 without a cast. Use templates to work around the problem when
134 template <typename T> inline T *
135 xrealloc (T *p, size_t s)
137 return (T *) xrealloc ((void *) p, s);
140 template <typename T> inline T *
141 xnrealloc (T *p, size_t n, size_t s)
143 return (T *) xnrealloc ((void *) p, n, s);
146 template <typename T> inline T *
147 x2realloc (T *p, size_t *pn)
149 return (T *) x2realloc ((void *) p, pn);
152 template <typename T> inline T *
153 x2nrealloc (T *p, size_t *pn, size_t s)
155 return (T *) x2nrealloc ((void *) p, pn, s);
158 template <typename T> inline T *
159 xmemdup (T const *p, size_t s)
161 return (T *) xmemdup ((void const *) p, s);
167 #endif /* !XALLOC_H_ */