1 /* xalloc.h -- malloc with out-of-memory checking
3 Copyright (C) 1990-2000, 2003-2004, 2006-2013 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"
25 _GL_INLINE_HEADER_BEGIN
27 # define XALLOC_INLINE _GL_INLINE
36 # define _GL_ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
38 # define _GL_ATTRIBUTE_MALLOC
41 #if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
42 # define _GL_ATTRIBUTE_ALLOC_SIZE(args) __attribute__ ((__alloc_size__ args))
44 # define _GL_ATTRIBUTE_ALLOC_SIZE(args)
47 /* This function is always triggered when memory is exhausted.
48 It must be defined by the application, either explicitly
49 or by using gnulib's xalloc-die module. This is the
50 function to call when one wants the program to die because of a
51 memory allocation failure. */
52 extern _Noreturn
void xalloc_die (void);
54 void *xmalloc (size_t s
)
55 _GL_ATTRIBUTE_MALLOC
_GL_ATTRIBUTE_ALLOC_SIZE ((1));
56 void *xzalloc (size_t s
)
57 _GL_ATTRIBUTE_MALLOC
_GL_ATTRIBUTE_ALLOC_SIZE ((1));
58 void *xcalloc (size_t n
, size_t s
)
59 _GL_ATTRIBUTE_MALLOC
_GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
60 void *xrealloc (void *p
, size_t s
)
61 _GL_ATTRIBUTE_ALLOC_SIZE ((2));
62 void *x2realloc (void *p
, size_t *pn
);
63 void *xmemdup (void const *p
, size_t s
)
64 _GL_ATTRIBUTE_MALLOC
_GL_ATTRIBUTE_ALLOC_SIZE ((2));
65 char *xstrdup (char const *str
)
68 /* In the following macros, T must be an elementary or structure/union or
69 typedef'ed type, or a pointer to such a type. To apply one of the
70 following macros to a function pointer or array type, you need to typedef
71 it first and use the typedef name. */
73 /* Allocate an object of type T dynamically, with error checking. */
74 /* extern t *XMALLOC (typename t); */
75 #define XMALLOC(t) ((t *) xmalloc (sizeof (t)))
77 /* Allocate memory for N elements of type T, with error checking. */
78 /* extern t *XNMALLOC (size_t n, typename t); */
79 #define XNMALLOC(n, t) \
80 ((t *) (sizeof (t) == 1 ? xmalloc (n) : xnmalloc (n, sizeof (t))))
82 /* Allocate an object of type T dynamically, with error checking,
84 /* extern t *XZALLOC (typename t); */
85 #define XZALLOC(t) ((t *) xzalloc (sizeof (t)))
87 /* Allocate memory for N elements of type T, with error checking,
89 /* extern t *XCALLOC (size_t n, typename t); */
90 #define XCALLOC(n, t) \
91 ((t *) (sizeof (t) == 1 ? xzalloc (n) : xcalloc (n, sizeof (t))))
94 /* Allocate an array of N objects, each with S bytes of memory,
95 dynamically, with error checking. S must be nonzero. */
97 XALLOC_INLINE
void *xnmalloc (size_t n
, size_t s
)
98 _GL_ATTRIBUTE_MALLOC
_GL_ATTRIBUTE_ALLOC_SIZE ((1, 2));
100 xnmalloc (size_t n
, size_t s
)
102 if (xalloc_oversized (n
, s
))
104 return xmalloc (n
* s
);
107 /* Change the size of an allocated block of memory P to an array of N
108 objects each of S bytes, with error checking. S must be nonzero. */
110 XALLOC_INLINE
void *xnrealloc (void *p
, size_t n
, size_t s
)
111 _GL_ATTRIBUTE_ALLOC_SIZE ((2, 3));
113 xnrealloc (void *p
, size_t n
, size_t s
)
115 if (xalloc_oversized (n
, s
))
117 return xrealloc (p
, n
* s
);
120 /* If P is null, allocate a block of at least *PN such objects;
121 otherwise, reallocate P so that it contains more than *PN objects
122 each of S bytes. *PN must be nonzero unless P is null, and S must
123 be nonzero. Set *PN to the new number of objects, and return the
124 pointer to the new block. *PN is never set to zero, and the
125 returned pointer is never null.
127 Repeated reallocations are guaranteed to make progress, either by
128 allocating an initial block with a nonzero size, or by allocating a
131 In the following implementation, nonzero sizes are increased by a
132 factor of approximately 1.5 so that repeated reallocations have
133 O(N) overall cost rather than O(N**2) cost, but the
134 specification for this function does not guarantee that rate.
136 Here is an example of use:
140 size_t allocated = 0;
143 append_int (int value)
145 if (used == allocated)
146 p = x2nrealloc (p, &allocated, sizeof *p);
150 This causes x2nrealloc to allocate a block of some nonzero size the
151 first time it is called.
153 To have finer-grained control over the initial size, set *PN to a
154 nonzero value before calling this function with P == NULL. For
159 size_t allocated = 0;
160 size_t allocated1 = 1000;
163 append_int (int value)
165 if (used == allocated)
167 p = x2nrealloc (p, &allocated1, sizeof *p);
168 allocated = allocated1;
176 x2nrealloc (void *p
, size_t *pn
, size_t s
)
184 /* The approximate size to use for initial small allocation
185 requests, when the invoking code specifies an old size of
186 zero. This is the largest "small" request for the GNU C
188 enum { DEFAULT_MXFAST
= 64 * sizeof (size_t) / 4 };
190 n
= DEFAULT_MXFAST
/ s
;
196 /* Set N = ceil (1.5 * N) so that progress is made if N == 1.
197 Check for overflow, so that N * S stays in size_t range.
198 The check is slightly conservative, but an exact check isn't
199 worth the trouble. */
200 if ((size_t) -1 / 3 * 2 / s
<= n
)
206 return xrealloc (p
, n
* s
);
209 /* Return a pointer to a new buffer of N bytes. This is like xmalloc,
210 except it returns char *. */
212 XALLOC_INLINE
char *xcharalloc (size_t n
)
213 _GL_ATTRIBUTE_MALLOC
_GL_ATTRIBUTE_ALLOC_SIZE ((1));
215 xcharalloc (size_t n
)
217 return XNMALLOC (n
, char);
223 /* C++ does not allow conversions from void * to other pointer types
224 without a cast. Use templates to work around the problem when
227 template <typename T
> inline T
*
228 xrealloc (T
*p
, size_t s
)
230 return (T
*) xrealloc ((void *) p
, s
);
233 template <typename T
> inline T
*
234 xnrealloc (T
*p
, size_t n
, size_t s
)
236 return (T
*) xnrealloc ((void *) p
, n
, s
);
239 template <typename T
> inline T
*
240 x2realloc (T
*p
, size_t *pn
)
242 return (T
*) x2realloc ((void *) p
, pn
);
245 template <typename T
> inline T
*
246 x2nrealloc (T
*p
, size_t *pn
, size_t s
)
248 return (T
*) x2nrealloc ((void *) p
, pn
, s
);
251 template <typename T
> inline T
*
252 xmemdup (T
const *p
, size_t s
)
254 return (T
*) xmemdup ((void const *) p
, s
);
260 #endif /* !XALLOC_H_ */