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[glibc.git] / dlfcn / dlfcn.h
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1 /* User functions for run-time dynamic loading.
2 Copyright (C) 1995-1999,2000,2001,2003 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library 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 GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #ifndef _DLFCN_H
21 #define _DLFCN_H 1
23 #include <features.h>
24 #define __need_size_t
25 #include <stddef.h>
27 /* Collect various system dependent definitions and declarations. */
28 #include <bits/dlfcn.h>
31 #ifdef __USE_GNU
32 /* If the first argument of `dlsym' or `dlvsym' is set to RTLD_NEXT
33 the run-time address of the symbol called NAME in the next shared
34 object is returned. The "next" relation is defined by the order
35 the shared objects were loaded. */
36 # define RTLD_NEXT ((void *) -1l)
38 /* If the first argument to `dlsym' or `dlvsym' is set to RTLD_DEFAULT
39 the run-time address of the symbol called NAME in the global scope
40 is returned. */
41 # define RTLD_DEFAULT ((void *) 0)
42 #endif
45 __BEGIN_DECLS
47 /* Open the shared object FILE and map it in; return a handle that can be
48 passed to `dlsym' to get symbol values from it. */
49 extern void *dlopen (__const char *__file, int __mode) __THROW;
51 /* Unmap and close a shared object opened by `dlopen'.
52 The handle cannot be used again after calling `dlclose'. */
53 extern int dlclose (void *__handle) __THROW;
55 /* Find the run-time address in the shared object HANDLE refers to
56 of the symbol called NAME. */
57 extern void *dlsym (void *__restrict __handle,
58 __const char *__restrict __name) __THROW;
60 #ifdef __USE_GNU
61 /* Find the run-time address in the shared object HANDLE refers to
62 of the symbol called NAME with VERSION. */
63 extern void *dlvsym (void *__restrict __handle,
64 __const char *__restrict __name,
65 __const char *__restrict __version) __THROW;
66 #endif
68 /* When any of the above functions fails, call this function
69 to return a string describing the error. Each call resets
70 the error string so that a following call returns null. */
71 extern char *dlerror (void) __THROW;
74 #ifdef __USE_GNU
75 /* Structure containing information about object searched using
76 `dladdr'. */
77 typedef struct
79 __const char *dli_fname; /* File name of defining object. */
80 void *dli_fbase; /* Load address of that object. */
81 __const char *dli_sname; /* Name of nearest symbol. */
82 void *dli_saddr; /* Exact value of nearest symbol. */
83 } Dl_info;
85 /* Fill in *INFO with the following information about ADDRESS.
86 Returns 0 iff no shared object's segments contain that address. */
87 extern int dladdr (__const void *__address, Dl_info *__info) __THROW;
89 /* Same as `dladdr', but additionally sets *EXTRA_INFO according to FLAGS. */
90 extern int dladdr1 (__const void *__address, Dl_info *__info,
91 void **__extra_info, int __flags) __THROW;
93 /* These are the possible values for the FLAGS argument to `dladdr1'.
94 This indicates what extra information is stored at *EXTRA_INFO.
95 It may also be zero, in which case the EXTRA_INFO argument is not used. */
96 enum
98 /* Matching symbol table entry (const ElfNN_Sym *). */
99 RTLD_DL_SYMENT = 1,
101 /* The object containing the address (struct link_map *). */
102 RTLD_DL_LINKMAP = 2
106 /* Get information about the shared object HANDLE refers to.
107 REQUEST is from among the values below, and determines the use of ARG.
109 On success, returns zero. On failure, returns -1 and records an error
110 message to be fetched with `dlerror'. */
111 extern int dlinfo (void *__restrict __handle,
112 int __request, void *__restrict __arg);
114 /* These are the possible values for the REQUEST argument to `dlinfo'. */
115 enum
117 /* Treat ARG as `struct link_map **';
118 store the `struct link_map *' for HANDLE there. */
119 RTLD_DI_LINKMAP = 2,
121 /* Treat ARG as `Dl_serinfo *' (see below), and fill in to describe the
122 directories that will be searched for dependencies of this object.
123 RTLD_DI_SERINFOSIZE fills in just the `dls_cnt' and `dls_size'
124 entries to indicate the size of the buffer that must be passed to
125 RTLD_DI_SERINFO to fill in the full information. */
126 RTLD_DI_SERINFO = 4,
127 RTLD_DI_SERINFOSIZE = 5,
129 /* Treat ARG as `char *', and store there the directory name used to
130 expand $ORIGIN in this shared object's dependency file names. */
131 RTLD_DI_ORIGIN = 6,
133 RTLD_DI_LMID = 1, /* Unsupported, defined by Solaris. */
134 RTLD_DI_CONFIGADDR = 3 /* Unsupported, defined by Solaris. */
138 /* This is the type of elements in `Dl_serinfo', below.
139 The `dls_name' member points to space in the buffer passed to `dlinfo'. */
140 typedef struct
142 char *dls_name; /* Name of library search path directory. */
143 unsigned int dls_flags; /* Indicates where this directory came from. */
144 } Dl_serpath;
146 /* This is the structure that must be passed (by reference) to `dlinfo' for
147 the RTLD_DI_SERINFO and RTLD_DI_SERINFOSIZE requests. */
148 typedef struct
150 size_t dls_size; /* Size in bytes of the whole buffer. */
151 unsigned int dls_cnt; /* Number of elements in `dls_serpath'. */
152 Dl_serpath dls_serpath[1]; /* Actually longer, dls_cnt elements. */
153 } Dl_serinfo;
154 #endif /* __USE_GNU */
157 __END_DECLS
159 #endif /* dlfcn.h */