1/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2/* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5
6#ifndef prlink_h___
7#define prlink_h___
8
9/*
10** API to static and dynamic linking.
11*/
12#include "prtypes.h"
13
14PR_BEGIN_EXTERN_C
15
16typedef struct PRLibrary PRLibrary;
17
18typedef struct PRStaticLinkTable {
19 const char *name;
20 void (*fp)(void);
21} PRStaticLinkTable;
22
23/*
24** Change the default library path to the given string. The string is
25** copied. This call will fail if it runs out of memory.
26**
27** The string provided as 'path' is copied. The caller can do whatever is
28** convenient with the argument when the function is complete.
29*/
30NSPR_API(PRStatus) PR_SetLibraryPath(const char *path);
31
32/*
33** Return a character string which contains the path used to search for
34** dynamically loadable libraries.
35**
36** The returned value is basically a copy of a PR_SetLibraryPath().
37** The storage is allocated by the runtime and becomes the responsibilty
38** of the caller.
39*/
40NSPR_API(char*) PR_GetLibraryPath(void);
41
42/*
43** Given a directory name "dir" and a library name "lib" construct a full
44** path name that will refer to the actual dynamically loaded
45** library. This does not test for existance of said file, it just
46** constructs the full filename. The name constructed is system dependent
47** and prepared for PR_LoadLibrary. The result must be free'd when the
48** caller is done with it.
49**
50** The storage for the result is allocated by the runtime and becomes the
51** responsibility of the caller.
52*/
53NSPR_API(char*) PR_GetLibraryName(const char *dir, const char *lib);
54
55/*
56**
57** Free the memory allocated, for the caller, by PR_GetLibraryName
58*/
59NSPR_API(void) PR_FreeLibraryName(char *mem);
60
61/*
62** Given a library "name" try to load the library. The argument "name"
63** is a machine-dependent name for the library, such as the full pathname
64** returned by PR_GetLibraryName. If the library is already loaded,
65** this function will avoid loading the library twice.
66**
67** If the library is loaded successfully, then a pointer to the PRLibrary
68** structure representing the library is returned. Otherwise, NULL is
69** returned.
70**
71** This increments the reference count of the library.
72*/
73NSPR_API(PRLibrary*) PR_LoadLibrary(const char *name);
74
75/*
76** Each operating system has its preferred way of specifying
77** a file in the file system. Most operating systems use
78** a pathname. Mac OS Classic, on the other hand, uses the FSSpec
79** structure to specify a file. PRLibSpec allows NSPR clients
80** to use the type of file specification that is most efficient
81** for a particular platform.
82**
83** On some operating systems such as Mac OS Classic, a shared library
84** may contain code fragments that can be individually loaded.
85** PRLibSpec also allows NSPR clients to identify a code fragment
86** in a library, if code fragments are supported by the OS.
87** A code fragment can be specified by name or by an integer index.
88**
89** Right now PRLibSpec supports four types of library specification:
90** a pathname in the native character encoding, a Mac code fragment
91** by name, a Mac code fragment by index, and a UTF-16 pathname.
92*/
93
94typedef enum PRLibSpecType {
95 PR_LibSpec_Pathname,
96 PR_LibSpec_MacNamedFragment, /* obsolete (for Mac OS Classic) */
97 PR_LibSpec_MacIndexedFragment, /* obsolete (for Mac OS Classic) */
98 PR_LibSpec_PathnameU /* supported only on Win32 */
99} PRLibSpecType;
100
101struct FSSpec; /* Mac OS Classic FSSpec */
102
103typedef struct PRLibSpec {
104 PRLibSpecType type;
105 union {
106 /* if type is PR_LibSpec_Pathname */
107 const char *pathname;
108
109 /* if type is PR_LibSpec_MacNamedFragment */
110 struct {
111 const struct FSSpec *fsspec;
112 const char *name;
113 } mac_named_fragment; /* obsolete (for Mac OS Classic) */
114
115 /* if type is PR_LibSpec_MacIndexedFragment */
116 struct {
117 const struct FSSpec *fsspec;
118 PRUint32 index;
119 } mac_indexed_fragment; /* obsolete (for Mac OS Classic) */
120
121 /* if type is PR_LibSpec_PathnameU */
122 const PRUnichar *pathname_u; /* supported only on Win32 */
123 } value;
124} PRLibSpec;
125
126/*
127** The following bit flags may be or'd together and passed
128** as the 'flags' argument to PR_LoadLibraryWithFlags.
129** Flags not supported by the underlying OS are ignored.
130*/
131
132#define PR_LD_LAZY 0x1 /* equivalent to RTLD_LAZY on Unix */
133#define PR_LD_NOW 0x2 /* equivalent to RTLD_NOW on Unix */
134#define PR_LD_GLOBAL 0x4 /* equivalent to RTLD_GLOBAL on Unix */
135#define PR_LD_LOCAL 0x8 /* equivalent to RTLD_LOCAL on Unix */
136/* The following is equivalent to LOAD_WITH_ALTERED_SEARCH_PATH on Windows */
137#define PR_LD_ALT_SEARCH_PATH 0x10
138/* 0x8000 reserved for NSPR internal use */
139
140/*
141** Load the specified library, in the manner specified by 'flags'.
142*/
143
144NSPR_API(PRLibrary *)
145PR_LoadLibraryWithFlags(
146 PRLibSpec libSpec, /* the shared library */
147 PRIntn flags /* flags that affect the loading */
148);
149
150/*
151** Unload a previously loaded library. If the library was a static
152** library then the static link table will no longer be referenced. The
153** associated PRLibrary object is freed.
154**
155** PR_FAILURE is returned if the library cannot be unloaded.
156**
157** This function decrements the reference count of the library.
158*/
159NSPR_API(PRStatus) PR_UnloadLibrary(PRLibrary *lib);
160
161/*
162** Given the name of a procedure, return the address of the function that
163** implements the procedure, or NULL if no such function can be
164** found. This does not find symbols in the main program (the ".exe");
165** use PR_LoadStaticLibrary to register symbols in the main program.
166**
167** This function does not modify the reference count of the library.
168*/
169NSPR_API(void*) PR_FindSymbol(PRLibrary *lib, const char *name);
170
171/*
172** Similar to PR_FindSymbol, except that the return value is a pointer to
173** a function, and not a pointer to void. Casting between a data pointer
174** and a function pointer is not portable according to the C standard.
175** Any function pointer can be cast to any other function pointer.
176**
177** This function does not modify the reference count of the library.
178*/
179typedef void (*PRFuncPtr)(void);
180NSPR_API(PRFuncPtr) PR_FindFunctionSymbol(PRLibrary *lib, const char *name);
181
182/*
183** Finds a symbol in one of the currently loaded libraries. Given the
184** name of a procedure, return the address of the function that
185** implements the procedure, and return the library that contains that
186** symbol, or NULL if no such function can be found. This does not find
187** symbols in the main program (the ".exe"); use PR_AddStaticLibrary to
188** register symbols in the main program.
189**
190** This increments the reference count of the library.
191*/
192NSPR_API(void*) PR_FindSymbolAndLibrary(const char *name,
193 PRLibrary* *lib);
194
195/*
196** Similar to PR_FindSymbolAndLibrary, except that the return value is
197** a pointer to a function, and not a pointer to void. Casting between a
198** data pointer and a function pointer is not portable according to the C
199** standard. Any function pointer can be cast to any other function pointer.
200**
201** This increments the reference count of the library.
202*/
203NSPR_API(PRFuncPtr) PR_FindFunctionSymbolAndLibrary(const char *name,
204 PRLibrary* *lib);
205
206/*
207** Register a static link table with the runtime under the name
208** "name". The symbols present in the static link table will be made
209** available to PR_FindSymbol. If "name" is null then the symbols will be
210** made available to the library which represents the executable. The
211** tables are not copied.
212**
213** Returns the library object if successful, null otherwise.
214**
215** This increments the reference count of the library.
216*/
217NSPR_API(PRLibrary*) PR_LoadStaticLibrary(
218 const char *name, const PRStaticLinkTable *table);
219
220/*
221** Return the pathname of the file that the library "name" was loaded
222** from. "addr" is the address of a function defined in the library.
223**
224** The caller is responsible for freeing the result with PR_Free.
225*/
226NSPR_API(char *) PR_GetLibraryFilePathname(const char *name, PRFuncPtr addr);
227
228PR_END_EXTERN_C
229
230#endif /* prlink_h___ */
231

source code of include/nspr/prlink.h