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/>. */
23 # include "xalloc-oversized.h"
31 # define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
33 # define _GL_ATTRIBUTE_MALLOC
36 # if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
37 # define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args))
39 # define _GL_ATTRIBUTE_ALLOC_SIZE(args)
42 /* This function is always triggered when memory is exhausted.
43 It must be defined by the application, either explicitly
44 or by using gnulib's xalloc-die module. This is the
45 function to call when one wants the program to die because of a
46 memory allocation failure. */
47 extern _Noreturn void xalloc_die (void);
49 void *xmalloc (size_t s)
50 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
51 void *xzalloc (size_t s)
52 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
53 void *xcalloc (size_t n, size_t s)
54 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
55 void *xrealloc (void *p, size_t s)
56 _GL_ATTRIBUTE_ALLOC_SIZE ((2));
57 void *x2realloc (void *p, size_t *pn);
58 void *xmemdup (void const *p, size_t s)
59 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((2));
60 char *xstrdup (char const *str)
63 /* In the following macros, T must be an elementary or structure/union or
64 typedef'ed type, or a pointer to such a type. To apply one of the
65 following macros to a function pointer or array type, you need to typedef
66 it first and use the typedef name. */
68 /* Allocate an object of type T dynamically, with error checking. */
69 /* extern t *XMALLOC (typename t); */
70 # define XMALLOC(t) ((t *) xmalloc (sizeof (t)))
72 /* Allocate memory for N elements of type T, with error checking. */
73 /* extern t *XNMALLOC (size_t n, typename t); */
74 # define XNMALLOC(n, t) \
75 ((t *) (sizeof (t) == 1 ? xmalloc (n) : xnmalloc (n, sizeof (t))))
77 /* Allocate an object of type T dynamically, with error checking,
79 /* extern t *XZALLOC (typename t); */
80 # define XZALLOC(t) ((t *) xzalloc (sizeof (t)))
82 /* Allocate memory for N elements of type T, with error checking,
84 /* extern t *XCALLOC (size_t n, typename t); */
85 # define XCALLOC(n, t) \
86 ((t *) (sizeof (t) == 1 ? xzalloc (n) : xcalloc (n, sizeof (t))))
90 # define static_inline static inline
92 void *xnmalloc (size_t n, size_t s)
93 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
94 void *xnrealloc (void *p, size_t n, size_t s)
95 _GL_ATTRIBUTE_ALLOC_SIZE ((2, 3));
96 void *x2nrealloc (void *p, size_t *pn, size_t s);
97 char *xcharalloc (size_t n)
98 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
101 # ifdef static_inline
103 /* Allocate an array of N objects, each with S bytes of memory,
104 dynamically, with error checking. S must be nonzero. */
106 static_inline void *xnmalloc (size_t n, size_t s)
107 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
109 xnmalloc (size_t n, size_t s)
111 if (xalloc_oversized (n, s))
113 return xmalloc (n * s);
116 /* Change the size of an allocated block of memory P to an array of N
117 objects each of S bytes, with error checking. S must be nonzero. */
119 static_inline void *xnrealloc (void *p, size_t n, size_t s)
120 _GL_ATTRIBUTE_ALLOC_SIZE ((2, 3));
122 xnrealloc (void *p, size_t n, size_t s)
124 if (xalloc_oversized (n, s))
126 return xrealloc (p, n * s);
129 /* If P is null, allocate a block of at least *PN such objects;
130 otherwise, reallocate P so that it contains more than *PN objects
131 each of S bytes. *PN must be nonzero unless P is null, and S must
132 be nonzero. Set *PN to the new number of objects, and return the
133 pointer to the new block. *PN is never set to zero, and the
134 returned pointer is never null.
136 Repeated reallocations are guaranteed to make progress, either by
137 allocating an initial block with a nonzero size, or by allocating a
140 In the following implementation, nonzero sizes are increased by a
141 factor of approximately 1.5 so that repeated reallocations have
142 O(N) overall cost rather than O(N**2) cost, but the
143 specification for this function does not guarantee that rate.
145 Here is an example of use:
149 size_t allocated = 0;
152 append_int (int value)
154 if (used == allocated)
155 p = x2nrealloc (p, &allocated, sizeof *p);
159 This causes x2nrealloc to allocate a block of some nonzero size the
160 first time it is called.
162 To have finer-grained control over the initial size, set *PN to a
163 nonzero value before calling this function with P == NULL. For
168 size_t allocated = 0;
169 size_t allocated1 = 1000;
172 append_int (int value)
174 if (used == allocated)
176 p = x2nrealloc (p, &allocated1, sizeof *p);
177 allocated = allocated1;
185 x2nrealloc (void *p, size_t *pn, size_t s)
193 /* The approximate size to use for initial small allocation
194 requests, when the invoking code specifies an old size of
195 zero. This is the largest "small" request for the GNU C
197 enum { DEFAULT_MXFAST = 64 * sizeof (size_t) / 4 };
199 n = DEFAULT_MXFAST / s;
205 /* Set N = ceil (1.5 * N) so that progress is made if N == 1.
206 Check for overflow, so that N * S stays in size_t range.
207 The check is slightly conservative, but an exact check isn't
208 worth the trouble. */
209 if ((size_t) -1 / 3 * 2 / s <= n)
215 return xrealloc (p, n * s);
218 /* Return a pointer to a new buffer of N bytes. This is like xmalloc,
219 except it returns char *. */
221 static_inline char *xcharalloc (size_t n)
222 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
224 xcharalloc (size_t n)
226 return XNMALLOC (n, char);
234 /* C++ does not allow conversions from void * to other pointer types
235 without a cast. Use templates to work around the problem when
238 template <typename T> inline T *
239 xrealloc (T *p, size_t s)
241 return (T *) xrealloc ((void *) p, s);
244 template <typename T> inline T *
245 xnrealloc (T *p, size_t n, size_t s)
247 return (T *) xnrealloc ((void *) p, n, s);
250 template <typename T> inline T *
251 x2realloc (T *p, size_t *pn)
253 return (T *) x2realloc ((void *) p, pn);
256 template <typename T> inline T *
257 x2nrealloc (T *p, size_t *pn, size_t s)
259 return (T *) x2nrealloc ((void *) p, pn, s);
262 template <typename T> inline T *
263 xmemdup (T const *p, size_t s)
265 return (T *) xmemdup ((void const *) p, s);
271 #endif /* !XALLOC_H_ */