1 /* xalloc.h -- malloc with out-of-memory checking
3 Copyright (C) 1990-2000, 2003-2004, 2006-2011 Free Software Foundation, Inc.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 # include <stdnoreturn.h>
24 # include "xalloc-oversized.h"
32 # define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
34 # define _GL_ATTRIBUTE_MALLOC
37 # if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
38 # define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args))
40 # define _GL_ATTRIBUTE_ALLOC_SIZE(args)
43 /* This function is always triggered when memory is exhausted.
44 It must be defined by the application, either explicitly
45 or by using gnulib's xalloc-die module. This is the
46 function to call when one wants the program to die because of a
47 memory allocation failure. */
48 extern noreturn void xalloc_die (void);
50 void *xmalloc (size_t s)
51 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
52 void *xzalloc (size_t s)
53 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
54 void *xcalloc (size_t n, size_t s)
55 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
56 void *xrealloc (void *p, size_t s)
57 _GL_ATTRIBUTE_ALLOC_SIZE ((2));
58 void *x2realloc (void *p, size_t *pn);
59 void *xmemdup (void const *p, size_t s)
60 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((2));
61 char *xstrdup (char const *str)
64 /* In the following macros, T must be an elementary or structure/union or
65 typedef'ed type, or a pointer to such a type. To apply one of the
66 following macros to a function pointer or array type, you need to typedef
67 it first and use the typedef name. */
69 /* Allocate an object of type T dynamically, with error checking. */
70 /* extern t *XMALLOC (typename t); */
71 # define XMALLOC(t) ((t *) xmalloc (sizeof (t)))
73 /* Allocate memory for N elements of type T, with error checking. */
74 /* extern t *XNMALLOC (size_t n, typename t); */
75 # define XNMALLOC(n, t) \
76 ((t *) (sizeof (t) == 1 ? xmalloc (n) : xnmalloc (n, sizeof (t))))
78 /* Allocate an object of type T dynamically, with error checking,
80 /* extern t *XZALLOC (typename t); */
81 # define XZALLOC(t) ((t *) xzalloc (sizeof (t)))
83 /* Allocate memory for N elements of type T, with error checking,
85 /* extern t *XCALLOC (size_t n, typename t); */
86 # define XCALLOC(n, t) \
87 ((t *) (sizeof (t) == 1 ? xzalloc (n) : xcalloc (n, sizeof (t))))
91 # define static_inline static inline
93 void *xnmalloc (size_t n, size_t s)
94 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
95 void *xnrealloc (void *p, size_t n, size_t s)
96 _GL_ATTRIBUTE_ALLOC_SIZE ((2, 3));
97 void *x2nrealloc (void *p, size_t *pn, size_t s);
98 char *xcharalloc (size_t n)
99 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
102 # ifdef static_inline
104 /* Allocate an array of N objects, each with S bytes of memory,
105 dynamically, with error checking. S must be nonzero. */
107 static_inline void *xnmalloc (size_t n, size_t s)
108 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
110 xnmalloc (size_t n, size_t s)
112 if (xalloc_oversized (n, s))
114 return xmalloc (n * s);
117 /* Change the size of an allocated block of memory P to an array of N
118 objects each of S bytes, with error checking. S must be nonzero. */
120 static_inline void *xnrealloc (void *p, size_t n, size_t s)
121 _GL_ATTRIBUTE_ALLOC_SIZE ((2, 3));
123 xnrealloc (void *p, size_t n, size_t s)
125 if (xalloc_oversized (n, s))
127 return xrealloc (p, n * s);
130 /* If P is null, allocate a block of at least *PN such objects;
131 otherwise, reallocate P so that it contains more than *PN objects
132 each of S bytes. *PN must be nonzero unless P is null, and S must
133 be nonzero. Set *PN to the new number of objects, and return the
134 pointer to the new block. *PN is never set to zero, and the
135 returned pointer is never null.
137 Repeated reallocations are guaranteed to make progress, either by
138 allocating an initial block with a nonzero size, or by allocating a
141 In the following implementation, nonzero sizes are increased by a
142 factor of approximately 1.5 so that repeated reallocations have
143 O(N) overall cost rather than O(N**2) cost, but the
144 specification for this function does not guarantee that rate.
146 Here is an example of use:
150 size_t allocated = 0;
153 append_int (int value)
155 if (used == allocated)
156 p = x2nrealloc (p, &allocated, sizeof *p);
160 This causes x2nrealloc to allocate a block of some nonzero size the
161 first time it is called.
163 To have finer-grained control over the initial size, set *PN to a
164 nonzero value before calling this function with P == NULL. For
169 size_t allocated = 0;
170 size_t allocated1 = 1000;
173 append_int (int value)
175 if (used == allocated)
177 p = x2nrealloc (p, &allocated1, sizeof *p);
178 allocated = allocated1;
186 x2nrealloc (void *p, size_t *pn, size_t s)
194 /* The approximate size to use for initial small allocation
195 requests, when the invoking code specifies an old size of
196 zero. 64 bytes is the largest "small" request for the
197 GNU C library malloc. */
198 enum { DEFAULT_MXFAST = 64 };
200 n = DEFAULT_MXFAST / s;
206 /* Set N = ceil (1.5 * N) so that progress is made if N == 1.
207 Check for overflow, so that N * S stays in size_t range.
208 The check is slightly conservative, but an exact check isn't
209 worth the trouble. */
210 if ((size_t) -1 / 3 * 2 / s <= n)
216 return xrealloc (p, n * s);
219 /* Return a pointer to a new buffer of N bytes. This is like xmalloc,
220 except it returns char *. */
222 static_inline char *xcharalloc (size_t n)
223 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
225 xcharalloc (size_t n)
227 return XNMALLOC (n, char);
235 /* C++ does not allow conversions from void * to other pointer types
236 without a cast. Use templates to work around the problem when
239 template <typename T> inline T *
240 xrealloc (T *p, size_t s)
242 return (T *) xrealloc ((void *) p, s);
245 template <typename T> inline T *
246 xnrealloc (T *p, size_t n, size_t s)
248 return (T *) xnrealloc ((void *) p, n, s);
251 template <typename T> inline T *
252 x2realloc (T *p, size_t *pn)
254 return (T *) x2realloc ((void *) p, pn);
257 template <typename T> inline T *
258 x2nrealloc (T *p, size_t *pn, size_t s)
260 return (T *) x2nrealloc ((void *) p, pn, s);
263 template <typename T> inline T *
264 xmemdup (T const *p, size_t s)
266 return (T *) xmemdup ((void const *) p, s);
272 #endif /* !XALLOC_H_ */