diff options
Diffstat (limited to 'lib/xmalloc.c')
-rw-r--r-- | lib/xmalloc.c | 210 |
1 files changed, 176 insertions, 34 deletions
diff --git a/lib/xmalloc.c b/lib/xmalloc.c index 3affee7a..181006b4 100644 --- a/lib/xmalloc.c +++ b/lib/xmalloc.c | |||
@@ -1,5 +1,7 @@ | |||
1 | /* xmalloc.c -- malloc with out of memory checking | 1 | /* xmalloc.c -- malloc with out of memory checking |
2 | Copyright (C) 1990-1999, 2000, 2002 Free Software Foundation, Inc. | 2 | |
3 | Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 2003, | ||
4 | 1999, 2000, 2002, 2003 Free Software Foundation, Inc. | ||
3 | 5 | ||
4 | This program is free software; you can redistribute it and/or modify | 6 | This program is free software; you can redistribute it and/or modify |
5 | it under the terms of the GNU General Public License as published by | 7 | it under the terms of the GNU General Public License as published by |
@@ -19,30 +21,22 @@ | |||
19 | # include <config.h> | 21 | # include <config.h> |
20 | #endif | 22 | #endif |
21 | 23 | ||
22 | #include <sys/types.h> | 24 | #include "xalloc.h" |
23 | 25 | ||
24 | #if STDC_HEADERS | 26 | #include <stdlib.h> |
25 | # include <stdlib.h> | 27 | #include <string.h> |
26 | #else | ||
27 | void *calloc (); | ||
28 | void *malloc (); | ||
29 | void *realloc (); | ||
30 | void free (); | ||
31 | #endif | ||
32 | 28 | ||
33 | #include "gettext.h" | 29 | #include "gettext.h" |
34 | #define _(msgid) gettext (msgid) | 30 | #define _(msgid) gettext (msgid) |
35 | #define N_(msgid) msgid | 31 | #define N_(msgid) msgid |
36 | 32 | ||
37 | #include "error.h" | 33 | #include "error.h" |
38 | #include "xalloc.h" | 34 | #include "exitfail.h" |
39 | 35 | ||
40 | #ifndef EXIT_FAILURE | 36 | #ifndef SIZE_MAX |
41 | # define EXIT_FAILURE 1 | 37 | # define SIZE_MAX ((size_t) -1) |
42 | #endif | 38 | #endif |
43 | 39 | ||
44 | /* The following tests require AC_PREREQ(2.54). */ | ||
45 | |||
46 | #ifndef HAVE_MALLOC | 40 | #ifndef HAVE_MALLOC |
47 | "you must run the autoconf test for a GNU libc compatible malloc" | 41 | "you must run the autoconf test for a GNU libc compatible malloc" |
48 | #endif | 42 | #endif |
@@ -51,12 +45,8 @@ void free (); | |||
51 | "you must run the autoconf test for a GNU libc compatible realloc" | 45 | "you must run the autoconf test for a GNU libc compatible realloc" |
52 | #endif | 46 | #endif |
53 | 47 | ||
54 | /* Exit value when the requested amount of memory is not available. | ||
55 | The caller may set it to some other value. */ | ||
56 | int xalloc_exit_failure = EXIT_FAILURE; | ||
57 | |||
58 | /* If non NULL, call this function when memory is exhausted. */ | 48 | /* If non NULL, call this function when memory is exhausted. */ |
59 | void (*xalloc_fail_func) PARAMS ((void)) = 0; | 49 | void (*xalloc_fail_func) (void) = 0; |
60 | 50 | ||
61 | /* If XALLOC_FAIL_FUNC is NULL, or does return, display this message | 51 | /* If XALLOC_FAIL_FUNC is NULL, or does return, display this message |
62 | before exiting when memory is exhausted. Goes through gettext. */ | 52 | before exiting when memory is exhausted. Goes through gettext. */ |
@@ -67,11 +57,29 @@ xalloc_die (void) | |||
67 | { | 57 | { |
68 | if (xalloc_fail_func) | 58 | if (xalloc_fail_func) |
69 | (*xalloc_fail_func) (); | 59 | (*xalloc_fail_func) (); |
70 | error (xalloc_exit_failure, 0, "%s", _(xalloc_msg_memory_exhausted)); | 60 | error (exit_failure, 0, "%s", _(xalloc_msg_memory_exhausted)); |
71 | /* The `noreturn' cannot be given to error, since it may return if | 61 | /* The `noreturn' cannot be given to error, since it may return if |
72 | its first argument is 0. To help compilers understand the | 62 | its first argument is 0. To help compilers understand the |
73 | xalloc_die does terminate, call exit. */ | 63 | xalloc_die does terminate, call abort. */ |
74 | exit (EXIT_FAILURE); | 64 | abort (); |
65 | } | ||
66 | |||
67 | /* Allocate an array of N objects, each with S bytes of memory, | ||
68 | dynamically, with error checking. S must be nonzero. */ | ||
69 | |||
70 | static inline void * | ||
71 | xnmalloc_inline (size_t n, size_t s) | ||
72 | { | ||
73 | void *p; | ||
74 | if (xalloc_oversized (n, s) || ! (p = malloc (n * s))) | ||
75 | xalloc_die (); | ||
76 | return p; | ||
77 | } | ||
78 | |||
79 | void * | ||
80 | xnmalloc (size_t n, size_t s) | ||
81 | { | ||
82 | return xnmalloc_inline (n, s); | ||
75 | } | 83 | } |
76 | 84 | ||
77 | /* Allocate N bytes of memory dynamically, with error checking. */ | 85 | /* Allocate N bytes of memory dynamically, with error checking. */ |
@@ -79,35 +87,169 @@ xalloc_die (void) | |||
79 | void * | 87 | void * |
80 | xmalloc (size_t n) | 88 | xmalloc (size_t n) |
81 | { | 89 | { |
82 | void *p; | 90 | return xnmalloc_inline (n, 1); |
91 | } | ||
92 | |||
93 | /* Change the size of an allocated block of memory P to an array of N | ||
94 | objects each of S bytes, with error checking. S must be nonzero. */ | ||
83 | 95 | ||
84 | p = malloc (n); | 96 | static inline void * |
85 | if (p == 0) | 97 | xnrealloc_inline (void *p, size_t n, size_t s) |
98 | { | ||
99 | if (xalloc_oversized (n, s) || ! (p = realloc (p, n * s))) | ||
86 | xalloc_die (); | 100 | xalloc_die (); |
87 | return p; | 101 | return p; |
88 | } | 102 | } |
89 | 103 | ||
104 | void * | ||
105 | xnrealloc (void *p, size_t n, size_t s) | ||
106 | { | ||
107 | return xnrealloc_inline (p, n, s); | ||
108 | } | ||
109 | |||
90 | /* Change the size of an allocated block of memory P to N bytes, | 110 | /* Change the size of an allocated block of memory P to N bytes, |
91 | with error checking. */ | 111 | with error checking. */ |
92 | 112 | ||
93 | void * | 113 | void * |
94 | xrealloc (void *p, size_t n) | 114 | xrealloc (void *p, size_t n) |
95 | { | 115 | { |
96 | p = realloc (p, n); | 116 | return xnrealloc_inline (p, n, 1); |
97 | if (p == 0) | ||
98 | xalloc_die (); | ||
99 | return p; | ||
100 | } | 117 | } |
101 | 118 | ||
102 | /* Allocate memory for N elements of S bytes, with error checking. */ | 119 | |
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. | ||
126 | |||
127 | Repeated reallocations are guaranteed to make progress, either by | ||
128 | allocating an initial block with a nonzero size, or by allocating a | ||
129 | larger block. | ||
130 | |||
131 | In the following implementation, nonzero sizes are doubled so that | ||
132 | repeated reallocations have O(N log N) overall cost rather than | ||
133 | O(N**2) cost, but the specification for this function does not | ||
134 | guarantee that sizes are doubled. | ||
135 | |||
136 | Here is an example of use: | ||
137 | |||
138 | int *p = NULL; | ||
139 | size_t used = 0; | ||
140 | size_t allocated = 0; | ||
141 | |||
142 | void | ||
143 | append_int (int value) | ||
144 | { | ||
145 | if (used == allocated) | ||
146 | p = x2nrealloc (p, &allocated, sizeof *p); | ||
147 | p[used++] = value; | ||
148 | } | ||
149 | |||
150 | This causes x2nrealloc to allocate a block of some nonzero size the | ||
151 | first time it is called. | ||
152 | |||
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 | ||
155 | example: | ||
156 | |||
157 | int *p = NULL; | ||
158 | size_t used = 0; | ||
159 | size_t allocated = 0; | ||
160 | size_t allocated1 = 1000; | ||
161 | |||
162 | void | ||
163 | append_int (int value) | ||
164 | { | ||
165 | if (used == allocated) | ||
166 | { | ||
167 | p = x2nrealloc (p, &allocated1, sizeof *p); | ||
168 | allocated = allocated1; | ||
169 | } | ||
170 | p[used++] = value; | ||
171 | } | ||
172 | |||
173 | */ | ||
174 | |||
175 | static inline void * | ||
176 | x2nrealloc_inline (void *p, size_t *pn, size_t s) | ||
177 | { | ||
178 | size_t n = *pn; | ||
179 | |||
180 | if (! p) | ||
181 | { | ||
182 | if (! n) | ||
183 | { | ||
184 | /* The approximate size to use for initial small allocation | ||
185 | requests, when the invoking code specifies an old size of | ||
186 | zero. 64 bytes is the largest "small" request for the | ||
187 | GNU C library malloc. */ | ||
188 | enum { DEFAULT_MXFAST = 64 }; | ||
189 | |||
190 | n = DEFAULT_MXFAST / s; | ||
191 | n += !n; | ||
192 | } | ||
193 | } | ||
194 | else | ||
195 | { | ||
196 | if (SIZE_MAX / 2 / s < n) | ||
197 | xalloc_die (); | ||
198 | n *= 2; | ||
199 | } | ||
200 | |||
201 | *pn = n; | ||
202 | return xrealloc (p, n * s); | ||
203 | } | ||
204 | |||
205 | void * | ||
206 | x2nrealloc (void *p, size_t *pn, size_t s) | ||
207 | { | ||
208 | return x2nrealloc_inline (p, pn, s); | ||
209 | } | ||
210 | |||
211 | /* If P is null, allocate a block of at least *PN bytes; otherwise, | ||
212 | reallocate P so that it contains more than *PN bytes. *PN must be | ||
213 | nonzero unless P is null. Set *PN to the new block's size, and | ||
214 | return the pointer to the new block. *PN is never set to zero, and | ||
215 | the returned pointer is never null. */ | ||
216 | |||
217 | void * | ||
218 | x2realloc (void *p, size_t *pn) | ||
219 | { | ||
220 | return x2nrealloc_inline (p, pn, 1); | ||
221 | } | ||
222 | |||
223 | /* Allocate S bytes of zeroed memory dynamically, with error checking. | ||
224 | There's no need for xnzalloc (N, S), since it would be equivalent | ||
225 | to xcalloc (N, S). */ | ||
226 | |||
227 | void * | ||
228 | xzalloc (size_t s) | ||
229 | { | ||
230 | return memset (xmalloc (s), 0, s); | ||
231 | } | ||
232 | |||
233 | /* Allocate zeroed memory for N elements of S bytes, with error | ||
234 | checking. S must be nonzero. */ | ||
103 | 235 | ||
104 | void * | 236 | void * |
105 | xcalloc (size_t n, size_t s) | 237 | xcalloc (size_t n, size_t s) |
106 | { | 238 | { |
107 | void *p; | 239 | void *p; |
108 | 240 | /* Test for overflow, since some calloc implementations don't have | |
109 | p = calloc (n, s); | 241 | proper overflow checks. */ |
110 | if (p == 0) | 242 | if (xalloc_oversized (n, s) || ! (p = calloc (n, s))) |
111 | xalloc_die (); | 243 | xalloc_die (); |
112 | return p; | 244 | return p; |
113 | } | 245 | } |
246 | |||
247 | /* Clone an object P of size S, with error checking. There's no need | ||
248 | for xnclone (P, N, S), since xclone (P, N * S) works without any | ||
249 | need for an arithmetic overflow check. */ | ||
250 | |||
251 | void * | ||
252 | xclone (void const *p, size_t s) | ||
253 | { | ||
254 | return memcpy (xmalloc (s), p, s); | ||
255 | } | ||