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"
30 # if __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8)
31 # define _GL_ATTRIBUTE_NORETURN __attribute__ ((__noreturn__))
33 # define _GL_ATTRIBUTE_NORETURN /* empty */
37 # define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
39 # define _GL_ATTRIBUTE_MALLOC
42 # if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
43 # define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args))
45 # define _GL_ATTRIBUTE_ALLOC_SIZE(args)
48 /* This function is always triggered when memory is exhausted.
49 It must be defined by the application, either explicitly
50 or by using gnulib's xalloc-die module. This is the
51 function to call when one wants the program to die because of a
52 memory allocation failure. */
53 extern void xalloc_die (void) _GL_ATTRIBUTE_NORETURN;
55 void *xmalloc (size_t s)
56 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
57 void *xzalloc (size_t s)
58 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
59 void *xcalloc (size_t n, size_t s)
60 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
61 void *xrealloc (void *p, size_t s)
62 _GL_ATTRIBUTE_ALLOC_SIZE ((2));
63 void *x2realloc (void *p, size_t *pn);
64 void *xmemdup (void const *p, size_t s)
65 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((2));
66 char *xstrdup (char const *str)
69 /* In the following macros, T must be an elementary or structure/union or
70 typedef'ed type, or a pointer to such a type. To apply one of the
71 following macros to a function pointer or array type, you need to typedef
72 it first and use the typedef name. */
74 /* Allocate an object of type T dynamically, with error checking. */
75 /* extern t *XMALLOC (typename t); */
76 # define XMALLOC(t) ((t *) xmalloc (sizeof (t)))
78 /* Allocate memory for N elements of type T, with error checking. */
79 /* extern t *XNMALLOC (size_t n, typename t); */
80 # define XNMALLOC(n, t) \
81 ((t *) (sizeof (t) == 1 ? xmalloc (n) : xnmalloc (n, sizeof (t))))
83 /* Allocate an object of type T dynamically, with error checking,
85 /* extern t *XZALLOC (typename t); */
86 # define XZALLOC(t) ((t *) xzalloc (sizeof (t)))
88 /* Allocate memory for N elements of type T, with error checking,
90 /* extern t *XCALLOC (size_t n, typename t); */
91 # define XCALLOC(n, t) \
92 ((t *) (sizeof (t) == 1 ? xzalloc (n) : xcalloc (n, sizeof (t))))
96 # define static_inline static inline
98 void *xnmalloc (size_t n, size_t s)
99 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
100 void *xnrealloc (void *p, size_t n, size_t s)
101 _GL_ATTRIBUTE_ALLOC_SIZE ((2, 3));
102 void *x2nrealloc (void *p, size_t *pn, size_t s);
103 char *xcharalloc (size_t n)
104 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
107 # ifdef static_inline
109 /* Allocate an array of N objects, each with S bytes of memory,
110 dynamically, with error checking. S must be nonzero. */
112 static_inline void *xnmalloc (size_t n, size_t s)
113 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
115 xnmalloc (size_t n, size_t s)
117 if (xalloc_oversized (n, s))
119 return xmalloc (n * s);
122 /* Change the size of an allocated block of memory P to an array of N
123 objects each of S bytes, with error checking. S must be nonzero. */
125 static_inline void *xnrealloc (void *p, size_t n, size_t s)
126 _GL_ATTRIBUTE_ALLOC_SIZE ((2, 3));
128 xnrealloc (void *p, size_t n, size_t s)
130 if (xalloc_oversized (n, s))
132 return xrealloc (p, n * s);
135 /* If P is null, allocate a block of at least *PN such objects;
136 otherwise, reallocate P so that it contains more than *PN objects
137 each of S bytes. *PN must be nonzero unless P is null, and S must
138 be nonzero. Set *PN to the new number of objects, and return the
139 pointer to the new block. *PN is never set to zero, and the
140 returned pointer is never null.
142 Repeated reallocations are guaranteed to make progress, either by
143 allocating an initial block with a nonzero size, or by allocating a
146 In the following implementation, nonzero sizes are increased by a
147 factor of approximately 1.5 so that repeated reallocations have
148 O(N) overall cost rather than O(N**2) cost, but the
149 specification for this function does not guarantee that rate.
151 Here is an example of use:
155 size_t allocated = 0;
158 append_int (int value)
160 if (used == allocated)
161 p = x2nrealloc (p, &allocated, sizeof *p);
165 This causes x2nrealloc to allocate a block of some nonzero size the
166 first time it is called.
168 To have finer-grained control over the initial size, set *PN to a
169 nonzero value before calling this function with P == NULL. For
174 size_t allocated = 0;
175 size_t allocated1 = 1000;
178 append_int (int value)
180 if (used == allocated)
182 p = x2nrealloc (p, &allocated1, sizeof *p);
183 allocated = allocated1;
191 x2nrealloc (void *p, size_t *pn, size_t s)
199 /* The approximate size to use for initial small allocation
200 requests, when the invoking code specifies an old size of
201 zero. 64 bytes is the largest "small" request for the
202 GNU C library malloc. */
203 enum { DEFAULT_MXFAST = 64 };
205 n = DEFAULT_MXFAST / s;
211 /* Set N = ceil (1.5 * N) so that progress is made if N == 1.
212 Check for overflow, so that N * S stays in size_t range.
213 The check is slightly conservative, but an exact check isn't
214 worth the trouble. */
215 if ((size_t) -1 / 3 * 2 / s <= n)
221 return xrealloc (p, n * s);
224 /* Return a pointer to a new buffer of N bytes. This is like xmalloc,
225 except it returns char *. */
227 static_inline char *xcharalloc (size_t n)
228 _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_ALLOC_SIZE ((1));
230 xcharalloc (size_t n)
232 return XNMALLOC (n, char);
240 /* C++ does not allow conversions from void * to other pointer types
241 without a cast. Use templates to work around the problem when
244 template <typename T> inline T *
245 xrealloc (T *p, size_t s)
247 return (T *) xrealloc ((void *) p, s);
250 template <typename T> inline T *
251 xnrealloc (T *p, size_t n, size_t s)
253 return (T *) xnrealloc ((void *) p, n, s);
256 template <typename T> inline T *
257 x2realloc (T *p, size_t *pn)
259 return (T *) x2realloc ((void *) p, pn);
262 template <typename T> inline T *
263 x2nrealloc (T *p, size_t *pn, size_t s)
265 return (T *) x2nrealloc ((void *) p, pn, s);
268 template <typename T> inline T *
269 xmemdup (T const *p, size_t s)
271 return (T *) xmemdup ((void const *) p, s);
277 #endif /* !XALLOC_H_ */