1 #ifndef HEADER_CURL_MEMORY_H
2 #define HEADER_CURL_MEMORY_H
3 /***************************************************************************
5 * Project ___| | | | _ \| |
7 * | (__| |_| | _ <| |___
8 * \___|\___/|_| \_\_____|
10 * Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
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.se/docs/copyright.html.
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.
20 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
21 * KIND, either express or implied.
23 * SPDX-License-Identifier: curl
25 ***************************************************************************/
28 * Nasty internal details ahead...
30 * File curl_memory.h must be included by _all_ *.c source files
31 * that use memory related functions strdup, malloc, calloc, realloc
32 * or free, and given source file is used to build libcurl library.
33 * It should be included immediately before memdebug.h as the last files
34 * included to avoid undesired interaction with other memory function
35 * headers in dependent libraries.
37 * There is nearly no exception to above rule. All libcurl source
38 * files in 'lib' subdirectory as well as those living deep inside
39 * 'packages' subdirectories and linked together in order to build
40 * libcurl library shall follow it.
42 * File lib/strdup.c is an exception, given that it provides a strdup
43 * clone implementation while using malloc. Extra care needed inside
46 * The need for curl_memory.h inclusion is due to libcurl's feature
47 * of allowing library user to provide memory replacement functions,
48 * memory callbacks, at runtime with curl_global_init_mem()
50 * Any *.c source file used to build libcurl library that does not
51 * include curl_memory.h and uses any memory function of the five
52 * mentioned above will compile without any indication, but it will
53 * trigger weird memory related issues at runtime.
55 * OTOH some source files from 'lib' subdirectory may additionally be
56 * used directly as source code when using some curlx_ functions by
57 * third party programs that don't even use libcurl at all. When using
58 * these source files in this way it is necessary these are compiled
59 * with CURLX_NO_MEMORY_CALLBACKS defined, in order to ensure that no
60 * attempt of calling libcurl's memory callbacks is done from code
61 * which can not use this machinery.
63 * Notice that libcurl's 'memory tracking' system works chaining into
64 * the memory callback machinery. This implies that when compiling
65 * 'lib' source files with CURLX_NO_MEMORY_CALLBACKS defined this file
66 * disengages usage of libcurl's 'memory tracking' system, defining
67 * MEMDEBUG_NODEFINES and overriding CURLDEBUG purpose.
69 * CURLX_NO_MEMORY_CALLBACKS takes precedence over CURLDEBUG. This is
70 * done in order to allow building a 'memory tracking' enabled libcurl
71 * and at the same time allow building programs which do not use it.
73 * Programs and libraries in 'tests' subdirectories have specific
74 * purposes and needs, and as such each one will use whatever fits
75 * best, depending additionally whether it links with libcurl or not.
77 * Caveat emptor. Proper curlx_* separation is a work in progress
78 * the same as CURLX_NO_MEMORY_CALLBACKS usage, some adjustments may
79 * still be required. IOW don't use them yet, there are sharp edges.
82 #ifdef HEADER_CURL_MEMDEBUG_H
83 #error "Header memdebug.h shall not be included before curl_memory.h"
86 #ifndef CURLX_NO_MEMORY_CALLBACKS
88 #ifndef CURL_DID_MEMORY_FUNC_TYPEDEFS /* only if not already done */
90 * The following memory function replacement typedef's are COPIED from
91 * curl/curl.h and MUST match the originals. We copy them to avoid having to
92 * include curl/curl.h here. We avoid that include since it includes stdio.h
93 * and other headers that may get messed up with defines done here.
95 typedef void *(*curl_malloc_callback)(size_t size);
96 typedef void (*curl_free_callback)(void *ptr);
97 typedef void *(*curl_realloc_callback)(void *ptr, size_t size);
98 typedef char *(*curl_strdup_callback)(const char *str);
99 typedef void *(*curl_calloc_callback)(size_t nmemb, size_t size);
100 #define CURL_DID_MEMORY_FUNC_TYPEDEFS
103 extern curl_malloc_callback Curl_cmalloc;
104 extern curl_free_callback Curl_cfree;
105 extern curl_realloc_callback Curl_crealloc;
106 extern curl_strdup_callback Curl_cstrdup;
107 extern curl_calloc_callback Curl_ccalloc;
108 #if defined(WIN32) && defined(UNICODE)
109 extern curl_wcsdup_callback Curl_cwcsdup;
115 * libcurl's 'memory tracking' system defines strdup, malloc, calloc,
116 * realloc and free, along with others, in memdebug.h in a different
117 * way although still using memory callbacks forward declared above.
118 * When using the 'memory tracking' system (CURLDEBUG defined) we do
119 * not define here the five memory functions given that definitions
120 * from memdebug.h are the ones that shall be used.
124 #define strdup(ptr) Curl_cstrdup(ptr)
126 #define malloc(size) Curl_cmalloc(size)
128 #define calloc(nbelem,size) Curl_ccalloc(nbelem, size)
130 #define realloc(ptr,size) Curl_crealloc(ptr, size)
132 #define free(ptr) Curl_cfree(ptr)
137 # define wcsdup(ptr) Curl_cwcsdup(ptr)
139 # define _wcsdup(ptr) Curl_cwcsdup(ptr)
141 # define _tcsdup(ptr) Curl_cwcsdup(ptr)
144 # define _tcsdup(ptr) Curl_cstrdup(ptr)
148 #endif /* CURLDEBUG */
150 #else /* CURLX_NO_MEMORY_CALLBACKS */
152 #ifndef MEMDEBUG_NODEFINES
153 #define MEMDEBUG_NODEFINES
156 #endif /* CURLX_NO_MEMORY_CALLBACKS */
158 #endif /* HEADER_CURL_MEMORY_H */