summaryrefslogtreecommitdiff
path: root/pr/include/prlink.h
blob: f0cea8296352e61f09040687146178eba4bb9684 (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
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is the Netscape Portable Runtime (NSPR).
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998-2000
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef prlink_h___
#define prlink_h___

/*
** API to static and dynamic linking.
*/
#include "prtypes.h"

PR_BEGIN_EXTERN_C

typedef struct PRLibrary PRLibrary;

typedef struct PRStaticLinkTable {
    const char *name;
    void (*fp)();
} PRStaticLinkTable;

/*
** Change the default library path to the given string. The string is
** copied. This call will fail if it runs out of memory.
**
** The string provided as 'path' is copied. The caller can do whatever is
** convenient with the argument when the function is complete.
*/
NSPR_API(PRStatus) PR_SetLibraryPath(const char *path);

/*
** Return a character string which contains the path used to search for
** dynamically loadable libraries.
**
** The returned value is basically a copy of a PR_SetLibraryPath().
** The storage is allocated by the runtime and becomes the responsibilty
** of the caller.
*/
NSPR_API(char*) PR_GetLibraryPath(void);

/*
** Given a directory name "dir" and a library name "lib" construct a full
** path name that will refer to the actual dynamically loaded
** library. This does not test for existance of said file, it just
** constructs the full filename. The name constructed is system dependent
** and prepared for PR_LoadLibrary. The result must be free'd when the
** caller is done with it.
**
** The storage for the result is allocated by the runtime and becomes the
** responsibility of the caller.
*/
NSPR_API(char*) PR_GetLibraryName(const char *dir, const char *lib);

/*
**
** Free the memory allocated, for the caller, by PR_GetLibraryName
*/
NSPR_API(void) PR_FreeLibraryName(char *mem);

/*
** Given a library "name" try to load the library. The argument "name"
** is a machine-dependent name for the library, such as the full pathname
** returned by PR_GetLibraryName.  If the library is already loaded,
** this function will avoid loading the library twice.
**
** If the library is loaded successfully, then a pointer to the PRLibrary
** structure representing the library is returned.  Otherwise, NULL is
** returned.
**
** This increments the reference count of the library.
*/
NSPR_API(PRLibrary*) PR_LoadLibrary(const char *name);

/*
** Each operating system has its preferred way of specifying
** a file in the file system.  Most operating systems use
** a pathname.  Mac OS, on the other hand, uses the FSSpec
** structure to specify a file. PRLibSpec allows NSPR clients
** to use the type of file specification that is most efficient
** for a particular platform.
**
** On some operating systems such as Mac OS, a shared library may
** contain code fragments that can be individually loaded.
** PRLibSpec also allows NSPR clients to identify a code fragment
** in a library, if code fragments are supported by the OS.
** A code fragment can be specified by name or by an integer index.
**
** Right now PRLibSpec supports four types of library specification:
** a pathname in the native character encoding, a Mac code fragment
** by name, a Mac code fragment by index, and a UTF-16 pathname.
*/

typedef enum PRLibSpecType {
    PR_LibSpec_Pathname,
    PR_LibSpec_MacNamedFragment,   /* obsolete (for Mac OS Classic) */
    PR_LibSpec_MacIndexedFragment, /* obsolete (for Mac OS Classic) */
    PR_LibSpec_PathnameU           /* supported only on Win32 */ 
} PRLibSpecType;

struct FSSpec; /* Mac OS FSSpec */

typedef struct PRLibSpec {
    PRLibSpecType type;
    union {
        /* if type is PR_LibSpec_Pathname */
        const char *pathname;

        /* if type is PR_LibSpec_MacNamedFragment */
        struct {
            const struct FSSpec *fsspec;
            const char *name;
        } mac_named_fragment;      /* obsolete (for Mac OS Classic) */

        /* if type is PR_LibSpec_MacIndexedFragment */
        struct {
            const struct FSSpec *fsspec;
            PRUint32 index;
        } mac_indexed_fragment;    /* obsolete (for Mac OS Classic) */

        /* if type is PR_LibSpec_PathnameU */
        const PRUnichar *pathname_u; /* supported only on Win32 */
    } value;
} PRLibSpec;

/*
** The following bit flags may be or'd together and passed
** as the 'flags' argument to PR_LoadLibraryWithFlags.
** Flags not supported by the underlying OS are ignored.
*/

#define PR_LD_LAZY   0x1  /* equivalent to RTLD_LAZY on Unix */
#define PR_LD_NOW    0x2  /* equivalent to RTLD_NOW on Unix */
#define PR_LD_GLOBAL 0x4  /* equivalent to RTLD_GLOBAL on Unix */
#define PR_LD_LOCAL  0x8  /* equivalent to RTLD_LOCAL on Unix */
/*                0x8000     reserved for NSPR internal use */

/*
** Load the specified library, in the manner specified by 'flags'.
*/

NSPR_API(PRLibrary *)
PR_LoadLibraryWithFlags(
    PRLibSpec libSpec,    /* the shared library */
    PRIntn flags          /* flags that affect the loading */
);

/*
** Unload a previously loaded library. If the library was a static
** library then the static link table will no longer be referenced. The
** associated PRLibrary object is freed.
**
** PR_FAILURE is returned if the library cannot be unloaded.
**
** This function decrements the reference count of the library.
*/
NSPR_API(PRStatus) PR_UnloadLibrary(PRLibrary *lib);

/*
** Given the name of a procedure, return the address of the function that
** implements the procedure, or NULL if no such function can be
** found. This does not find symbols in the main program (the ".exe");
** use PR_LoadStaticLibrary to register symbols in the main program.
**
** This function does not modify the reference count of the library.
*/
NSPR_API(void*) PR_FindSymbol(PRLibrary *lib, const char *name);

/*
** Similar to PR_FindSymbol, except that the return value is a pointer to
** a function, and not a pointer to void. Casting between a data pointer
** and a function pointer is not portable according to the C standard.
** Any function pointer can be cast to any other function pointer.
**
** This function does not modify the reference count of the library.
*/
typedef void (*PRFuncPtr)();
NSPR_API(PRFuncPtr) PR_FindFunctionSymbol(PRLibrary *lib, const char *name);

/*
** Finds a symbol in one of the currently loaded libraries. Given the
** name of a procedure, return the address of the function that
** implements the procedure, and return the library that contains that
** symbol, or NULL if no such function can be found. This does not find
** symbols in the main program (the ".exe"); use PR_AddStaticLibrary to
** register symbols in the main program.  
**
** This increments the reference count of the library.
*/
NSPR_API(void*) PR_FindSymbolAndLibrary(const char *name,
						      PRLibrary* *lib);

/*
** Similar to PR_FindSymbolAndLibrary, except that the return value is
** a pointer to a function, and not a pointer to void. Casting between a
** data pointer and a function pointer is not portable according to the C
** standard. Any function pointer can be cast to any other function pointer.
**
** This increments the reference count of the library.
*/
NSPR_API(PRFuncPtr) PR_FindFunctionSymbolAndLibrary(const char *name,
						      PRLibrary* *lib);

/*
** Register a static link table with the runtime under the name
** "name". The symbols present in the static link table will be made
** available to PR_FindSymbol. If "name" is null then the symbols will be
** made available to the library which represents the executable. The
** tables are not copied.
**
** Returns the library object if successful, null otherwise.
**
** This increments the reference count of the library.
*/
NSPR_API(PRLibrary*) PR_LoadStaticLibrary(
    const char *name, const PRStaticLinkTable *table);

/*
** Return the pathname of the file that the library "name" was loaded
** from. "addr" is the address of a function defined in the library.
**
** The caller is responsible for freeing the result with PR_Free.
*/
NSPR_API(char *) PR_GetLibraryFilePathname(const char *name, PRFuncPtr addr);

PR_END_EXTERN_C

#endif /* prlink_h___ */