curl_memory.h revision e6cd738ed3716c02557fb3a47515244e949ade39 
1#ifndef HEADER_CURL_MEMORY_H
2#define HEADER_CURL_MEMORY_H
3/***************************************************************************
4 *                                  _   _ ____  _
5 *  Project                     ___| | | |  _ \| |
6 *                             / __| | | | |_) | |
7 *                            | (__| |_| |  _ <| |___
8 *                             \___|\___/|_| \_\_____|
9 *
10 * Copyright (C) 1998 - 2013, Daniel Stenberg, <daniel@haxx.se>, et al.
11 *
12 * This software is licensed as described in the file COPYING, which
13 * you should have received as part of this distribution. The terms
14 * are also available at http://curl.haxx.se/docs/copyright.html.
15 *
16 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
17 * copies of the Software, and permit persons to whom the Software is
18 * furnished to do so, under the terms of the COPYING file.
19 *
20 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
21 * KIND, either express or implied.
22 *
23 ***************************************************************************/
24
25/*
26 * Nasty internal details ahead...
27 *
28 * File curl_memory.h must be included by _all_ *.c source files
29 * that use memory related functions strdup, malloc, calloc, realloc
30 * or free, and given source file is used to build libcurl library.
31 * It should be included immediately before memdebug.h as the last files
32 * included to avoid undesired interaction with other memory function
33 * headers in dependent libraries.
34 *
35 * There is nearly no exception to above rule. All libcurl source
36 * files in 'lib' subdirectory as well as those living deep inside
37 * 'packages' subdirectories and linked together in order to build
38 * libcurl library shall follow it.
39 *
40 * File lib/strdup.c is an exception, given that it provides a strdup
41 * clone implementation while using malloc. Extra care needed inside
42 * this one. TODO: revisit this paragraph and related code.
43 *
44 * The need for curl_memory.h inclusion is due to libcurl's feature
45 * of allowing library user to provide memory replacement functions,
46 * memory callbacks, at runtime with curl_global_init_mem()
47 *
48 * Any *.c source file used to build libcurl library that does not
49 * include curl_memory.h and uses any memory function of the five
50 * mentioned above will compile without any indication, but it will
51 * trigger weird memory related issues at runtime.
52 *
53 * OTOH some source files from 'lib' subdirectory may additionally be
54 * used directly as source code when using some curlx_ functions by
55 * third party programs that don't even use libcurl at all. When using
56 * these source files in this way it is necessary these are compiled
57 * with CURLX_NO_MEMORY_CALLBACKS defined, in order to ensure that no
58 * attempt of calling libcurl's memory callbacks is done from code
59 * which can not use this machinery.
60 *
61 * Notice that libcurl's 'memory tracking' system works chaining into
62 * the memory callback machinery. This implies that when compiling
63 * 'lib' source files with CURLX_NO_MEMORY_CALLBACKS defined this file
64 * disengages usage of libcurl's 'memory tracking' system, defining
65 * MEMDEBUG_NODEFINES and overriding CURLDEBUG purpose.
66 *
67 * CURLX_NO_MEMORY_CALLBACKS takes precedence over CURLDEBUG. This is
68 * done in order to allow building a 'memory tracking' enabled libcurl
69 * and at the same time allow building programs which do not use it.
70 *
71 * Programs and libraries in 'tests' subdirectories have specific
72 * purposes and needs, and as such each one will use whatever fits
73 * best, depending additionally wether it links with libcurl or not.
74 *
75 * Caveat emptor. Proper curlx_* separation is a work in progress
76 * the same as CURLX_NO_MEMORY_CALLBACKS usage, some adjustments may
77 * still be required. IOW don't use them yet, there are sharp edges.
78 */
79
80#ifdef HEADER_CURL_MEMDEBUG_H
81#error "Header memdebug.h shall not be included before curl_memory.h"
82#endif
83
84#ifndef CURLX_NO_MEMORY_CALLBACKS
85
86#include <curl/curl.h> /* for the callback typedefs */
87
88extern curl_malloc_callback Curl_cmalloc;
89extern curl_free_callback Curl_cfree;
90extern curl_realloc_callback Curl_crealloc;
91extern curl_strdup_callback Curl_cstrdup;
92extern curl_calloc_callback Curl_ccalloc;
93#if defined(WIN32) && defined(UNICODE)
94extern curl_wcsdup_callback Curl_cwcsdup;
95#endif
96
97#ifndef CURLDEBUG
98
99/*
100 * libcurl's 'memory tracking' system defines strdup, malloc, calloc,
101 * realloc and free, along with others, in memdebug.h in a different
102 * way although still using memory callbacks forward declared above.
103 * When using the 'memory tracking' system (CURLDEBUG defined) we do
104 * not define here the five memory functions given that definitions
105 * from memdebug.h are the ones that shall be used.
106 */
107
108#undef strdup
109#define strdup(ptr) Curl_cstrdup(ptr)
110#undef malloc
111#define malloc(size) Curl_cmalloc(size)
112#undef calloc
113#define calloc(nbelem,size) Curl_ccalloc(nbelem, size)
114#undef realloc
115#define realloc(ptr,size) Curl_crealloc(ptr, size)
116#undef free
117#define free(ptr) Curl_cfree(ptr)
118
119#ifdef WIN32
120#  ifdef UNICODE
121#    undef wcsdup
122#    define wcsdup(ptr) Curl_cwcsdup(ptr)
123#    undef _wcsdup
124#    define _wcsdup(ptr) Curl_cwcsdup(ptr)
125#    undef _tcsdup
126#    define _tcsdup(ptr) Curl_cwcsdup(ptr)
127#  else
128#    undef _tcsdup
129#    define _tcsdup(ptr) Curl_cstrdup(ptr)
130#  endif
131#endif
132
133#endif /* CURLDEBUG */
134
135#else /* CURLX_NO_MEMORY_CALLBACKS */
136
137#ifndef MEMDEBUG_NODEFINES
138#define MEMDEBUG_NODEFINES
139#endif
140
141#endif /* CURLX_NO_MEMORY_CALLBACKS */
142
143#endif /* HEADER_CURL_MEMORY_H */
144