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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 :
14 : PR_BEGIN_EXTERN_C
15 :
16 : typedef struct PRLibrary PRLibrary;
17 :
18 : typedef 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 : */
30 0 : NSPR_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 : */
40 0 : NSPR_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 : */
53 1 : NSPR_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 : */
59 1 : NSPR_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 : */
73 3 : NSPR_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 :
94 : typedef 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 :
101 : struct FSSpec; /* Mac OS Classic FSSpec */
102 :
103 : typedef 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 :
144 : NSPR_API(PRLibrary *)
145 8 : PR_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 : */
159 0 : NSPR_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 : */
169 21 : NSPR_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 : */
179 : typedef void (*PRFuncPtr)(void);
180 14 : NSPR_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 : */
192 0 : NSPR_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 : */
203 0 : NSPR_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 : */
217 0 : NSPR_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 : */
226 6 : NSPR_API(char *) PR_GetLibraryFilePathname(const char *name, PRFuncPtr addr);
227 :
228 : PR_END_EXTERN_C
229 :
230 : #endif /* prlink_h___ */
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