aboutsummaryrefslogtreecommitdiff
path: root/dlfcn/dlfcn.h
blob: d4a8d5ac0146eab0dca289db7b48001b0da56a8b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
/* User functions for run-time dynamic loading.
   Copyright (C) 1995-2020 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#ifndef	_DLFCN_H
#define	_DLFCN_H 1

#include <features.h>
#define __need_size_t
#include <stddef.h>

/* Collect various system dependent definitions and declarations.  */
#include <bits/dlfcn.h>


#ifdef __USE_GNU
/* If the first argument of `dlsym' or `dlvsym' is set to RTLD_NEXT
   the run-time address of the symbol called NAME in the next shared
   object is returned.  The "next" relation is defined by the order
   the shared objects were loaded.  */
# define RTLD_NEXT	((void *) -1l)

/* If the first argument to `dlsym' or `dlvsym' is set to RTLD_DEFAULT
   the run-time address of the symbol called NAME in the global scope
   is returned.  */
# define RTLD_DEFAULT	((void *) 0)


/* Type for namespace indices.  */
typedef long int Lmid_t;

/* Special namespace ID values.  */
# define LM_ID_BASE	0	/* Initial namespace.  */
# define LM_ID_NEWLM	-1	/* For dlmopen: request new namespace.  */
#endif


__BEGIN_DECLS

/* Open the shared object FILE and map it in; return a handle that can be
   passed to `dlsym' to get symbol values from it.  */
extern void *dlopen (const char *__file, int __mode) __THROWNL;

/* Unmap and close a shared object opened by `dlopen'.
   The handle cannot be used again after calling `dlclose'.  */
extern int dlclose (void *__handle) __THROWNL __nonnull ((1));

/* Find the run-time address in the shared object HANDLE refers to
   of the symbol called NAME.  */
extern void *dlsym (void *__restrict __handle,
		    const char *__restrict __name) __THROW __nonnull ((2));

#ifdef __USE_GNU
/* Like `dlopen', but request object to be allocated in a new namespace.  */
extern void *dlmopen (Lmid_t __nsid, const char *__file, int __mode) __THROWNL;

/* Find the run-time address in the shared object HANDLE refers to
   of the symbol called NAME with VERSION.  */
extern void *dlvsym (void *__restrict __handle,
		     const char *__restrict __name,
		     const char *__restrict __version)
     __THROW __nonnull ((2, 3));
#endif

/* When any of the above functions fails, call this function
   to return a string describing the error.  Each call resets
   the error string so that a following call returns null.  */
extern char *dlerror (void) __THROW;


#ifdef __USE_GNU
/* Structure containing information about object searched using
   `dladdr'.  */
typedef struct
{
  const char *dli_fname;	/* File name of defining object.  */
  void *dli_fbase;		/* Load address of that object.  */
  const char *dli_sname;	/* Name of nearest symbol.  */
  void *dli_saddr;		/* Exact value of nearest symbol.  */
} Dl_info;

/* Fill in *INFO with the following information about ADDRESS.
   Returns 0 iff no shared object's segments contain that address.  */
extern int dladdr (const void *__address, Dl_info *__info)
     __THROW __nonnull ((2));

/* Same as `dladdr', but additionally sets *EXTRA_INFO according to FLAGS.  */
extern int dladdr1 (const void *__address, Dl_info *__info,
		    void **__extra_info, int __flags) __THROW __nonnull ((2));

/* These are the possible values for the FLAGS argument to `dladdr1'.
   This indicates what extra information is stored at *EXTRA_INFO.
   It may also be zero, in which case the EXTRA_INFO argument is not used.  */
enum
  {
    /* Matching symbol table entry (const ElfNN_Sym *).  */
    RTLD_DL_SYMENT = 1,

    /* The object containing the address (struct link_map *).  */
    RTLD_DL_LINKMAP = 2
  };


/* Get information about the shared object HANDLE refers to.
   REQUEST is from among the values below, and determines the use of ARG.

   On success, returns zero.  On failure, returns -1 and records an error
   message to be fetched with `dlerror'.  */
extern int dlinfo (void *__restrict __handle,
		   int __request, void *__restrict __arg)
     __THROW __nonnull ((1, 3));

/* These are the possible values for the REQUEST argument to `dlinfo'.  */
enum
  {
    /* Treat ARG as `lmid_t *'; store namespace ID for HANDLE there.  */
    RTLD_DI_LMID = 1,

    /* Treat ARG as `struct link_map **';
       store the `struct link_map *' for HANDLE there.  */
    RTLD_DI_LINKMAP = 2,

    RTLD_DI_CONFIGADDR = 3,	/* Unsupported, defined by Solaris.  */

    /* Treat ARG as `Dl_serinfo *' (see below), and fill in to describe the
       directories that will be searched for dependencies of this object.
       RTLD_DI_SERINFOSIZE fills in just the `dls_cnt' and `dls_size'
       entries to indicate the size of the buffer that must be passed to
       RTLD_DI_SERINFO to fill in the full information.  */
    RTLD_DI_SERINFO = 4,
    RTLD_DI_SERINFOSIZE = 5,

    /* Treat ARG as `char *', and store there the directory name used to
       expand $ORIGIN in this shared object's dependency file names.  */
    RTLD_DI_ORIGIN = 6,

    RTLD_DI_PROFILENAME = 7,	/* Unsupported, defined by Solaris.  */
    RTLD_DI_PROFILEOUT = 8,	/* Unsupported, defined by Solaris.  */

    /* Treat ARG as `size_t *', and store there the TLS module ID
       of this object's PT_TLS segment, as used in TLS relocations;
       store zero if this object does not define a PT_TLS segment.  */
    RTLD_DI_TLS_MODID = 9,

    /* Treat ARG as `void **', and store there a pointer to the calling
       thread's TLS block corresponding to this object's PT_TLS segment.
       Store a null pointer if this object does not define a PT_TLS
       segment, or if the calling thread has not allocated a block for it.  */
    RTLD_DI_TLS_DATA = 10,

    RTLD_DI_MAX = 10
  };


/* This is the type of elements in `Dl_serinfo', below.
   The `dls_name' member points to space in the buffer passed to `dlinfo'.  */
typedef struct
{
  char *dls_name;		/* Name of library search path directory.  */
  unsigned int dls_flags;	/* Indicates where this directory came from. */
} Dl_serpath;

/* This is the structure that must be passed (by reference) to `dlinfo' for
   the RTLD_DI_SERINFO and RTLD_DI_SERINFOSIZE requests.  */
typedef struct
{
  size_t dls_size;		/* Size in bytes of the whole buffer.  */
  unsigned int dls_cnt;		/* Number of elements in `dls_serpath'.  */
# if __GNUC_PREREQ (3, 0)
  /* The zero-length array avoids an unwanted array subscript check by
     the compiler, while the surrounding anonymous union preserves the
     historic size of the type.  At the time of writing, GNU C does
     not support structs with flexible array members in unions.  */
  __extension__ union
  {
    Dl_serpath dls_serpath[0]; /* Actually longer, dls_cnt elements.  */
    Dl_serpath __dls_serpath_pad[1];
  };
# else
  Dl_serpath dls_serpath[1];	/* Actually longer, dls_cnt elements.  */
# endif
} Dl_serinfo;
#endif /* __USE_GNU */


__END_DECLS

#endif	/* dlfcn.h */