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1 #ifndef HEADER_CURL_MEMORY_H
2 #define HEADER_CURL_MEMORY_H
3 /***************************************************************************
4  *                                  _   _ ____  _
5  *  Project                     ___| | | |  _ \| |
6  *                             / __| | | | |_) | |
7  *                            | (__| |_| |  _ <| |___
8  *                             \___|\___/|_| \_\_____|
9  *
10  * Copyright (C) 1998 - 2019, 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 https://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.
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 whether 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 #ifndef CURL_DID_MEMORY_FUNC_TYPEDEFS /* only if not already done */
87 /*
88  * The following memory function replacement typedef's are COPIED from
89  * curl/curl.h and MUST match the originals. We copy them to avoid having to
90  * include curl/curl.h here. We avoid that include since it includes stdio.h
91  * and other headers that may get messed up with defines done here.
92  */
93 typedef void *(*curl_malloc_callback)(size_t size);
94 typedef void (*curl_free_callback)(void *ptr);
95 typedef void *(*curl_realloc_callback)(void *ptr, size_t size);
96 typedef char *(*curl_strdup_callback)(const char *str);
97 typedef void *(*curl_calloc_callback)(size_t nmemb, size_t size);
98 #define CURL_DID_MEMORY_FUNC_TYPEDEFS
99 #endif
100 
101 extern curl_malloc_callback Curl_cmalloc;
102 extern curl_free_callback Curl_cfree;
103 extern curl_realloc_callback Curl_crealloc;
104 extern curl_strdup_callback Curl_cstrdup;
105 extern curl_calloc_callback Curl_ccalloc;
106 #if defined(WIN32) && defined(UNICODE)
107 extern curl_wcsdup_callback Curl_cwcsdup;
108 #endif
109 
110 #ifndef CURLDEBUG
111 
112 /*
113  * libcurl's 'memory tracking' system defines strdup, malloc, calloc,
114  * realloc and free, along with others, in memdebug.h in a different
115  * way although still using memory callbacks forward declared above.
116  * When using the 'memory tracking' system (CURLDEBUG defined) we do
117  * not define here the five memory functions given that definitions
118  * from memdebug.h are the ones that shall be used.
119  */
120 
121 #undef strdup
122 #define strdup(ptr) Curl_cstrdup(ptr)
123 #undef malloc
124 #define malloc(size) Curl_cmalloc(size)
125 #undef calloc
126 #define calloc(nbelem,size) Curl_ccalloc(nbelem, size)
127 #undef realloc
128 #define realloc(ptr,size) Curl_crealloc(ptr, size)
129 #undef free
130 #define free(ptr) Curl_cfree(ptr)
131 
132 #ifdef WIN32
133 #  ifdef UNICODE
134 #    undef wcsdup
135 #    define wcsdup(ptr) Curl_cwcsdup(ptr)
136 #    undef _wcsdup
137 #    define _wcsdup(ptr) Curl_cwcsdup(ptr)
138 #    undef _tcsdup
139 #    define _tcsdup(ptr) Curl_cwcsdup(ptr)
140 #  else
141 #    undef _tcsdup
142 #    define _tcsdup(ptr) Curl_cstrdup(ptr)
143 #  endif
144 #endif
145 
146 #endif /* CURLDEBUG */
147 
148 #else /* CURLX_NO_MEMORY_CALLBACKS */
149 
150 #ifndef MEMDEBUG_NODEFINES
151 #define MEMDEBUG_NODEFINES
152 #endif
153 
154 #endif /* CURLX_NO_MEMORY_CALLBACKS */
155 
156 #endif /* HEADER_CURL_MEMORY_H */
157