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a0d0e21e LW |
1 | /* dl_dlopen.xs |
2 | * | |
3 | * Platform: SunOS/Solaris, possibly others which use dlopen. | |
0536e0eb | 4 | * Author: Paul Marquess (Paul.Marquess@btinternet.com) |
a0d0e21e LW |
5 | * Created: 10th July 1994 |
6 | * | |
7 | * Modified: | |
abb9e9dc GS |
8 | * 15th July 1994 - Added code to explicitly save any error messages. |
9 | * 3rd August 1994 - Upgraded to v3 spec. | |
10 | * 9th August 1994 - Changed to use IV | |
11 | * 10th August 1994 - Tim Bunce: Added RTLD_LAZY, switchable debugging, | |
12 | * basic FreeBSD support, removed ClearError | |
13 | * 29th Feburary 2000 - Alan Burlison: Added functionality to close dlopen'd | |
14 | * files when the interpreter exits | |
a0d0e21e LW |
15 | * |
16 | */ | |
17 | ||
18 | /* Porting notes: | |
19 | ||
20 | ||
21 | Definition of Sunos dynamic Linking functions | |
22 | ============================================= | |
23 | In order to make this implementation easier to understand here is a | |
24 | quick definition of the SunOS Dynamic Linking functions which are | |
25 | used here. | |
26 | ||
27 | dlopen | |
28 | ------ | |
29 | void * | |
30 | dlopen(path, mode) | |
31 | char * path; | |
32 | int mode; | |
33 | ||
34 | This function takes the name of a dynamic object file and returns | |
35 | a descriptor which can be used by dlsym later. It returns NULL on | |
36 | error. | |
37 | ||
38 | The mode parameter must be set to 1 for Solaris 1 and to | |
8e07c86e | 39 | RTLD_LAZY (==2) on Solaris 2. |
a0d0e21e LW |
40 | |
41 | ||
abb9e9dc GS |
42 | dlclose |
43 | ------- | |
44 | int | |
45 | dlclose(handle) | |
46 | void * handle; | |
47 | ||
48 | This function takes the handle returned by a previous invocation of | |
49 | dlopen and closes the associated dynamic object file. It returns zero | |
50 | on success, and non-zero on failure. | |
51 | ||
52 | ||
a0d0e21e LW |
53 | dlsym |
54 | ------ | |
55 | void * | |
56 | dlsym(handle, symbol) | |
57 | void * handle; | |
58 | char * symbol; | |
59 | ||
60 | Takes the handle returned from dlopen and the name of a symbol to | |
61 | get the address of. If the symbol was found a pointer is | |
62 | returned. It returns NULL on error. If DL_PREPEND_UNDERSCORE is | |
63 | defined an underscore will be added to the start of symbol. This | |
64 | is required on some platforms (freebsd). | |
65 | ||
66 | dlerror | |
67 | ------ | |
68 | char * dlerror() | |
69 | ||
70 | Returns a null-terminated string which describes the last error | |
71 | that occurred with either dlopen or dlsym. After each call to | |
72 | dlerror the error message will be reset to a null pointer. The | |
abb9e9dc | 73 | SaveError function is used to save the error as soon as it happens. |
a0d0e21e LW |
74 | |
75 | ||
76 | Return Types | |
77 | ============ | |
78 | In this implementation the two functions, dl_load_file & | |
79 | dl_find_symbol, return void *. This is because the underlying SunOS | |
80 | dynamic linker calls also return void *. This is not necessarily | |
81 | the case for all architectures. For example, some implementation | |
82 | will want to return a char * for dl_load_file. | |
83 | ||
84 | If void * is not appropriate for your architecture, you will have to | |
85 | change the void * to whatever you require. If you are not certain of | |
86 | how Perl handles C data types, I suggest you start by consulting | |
87 | Dean Roerich's Perl 5 API document. Also, have a look in the typemap | |
88 | file (in the ext directory) for a fairly comprehensive list of types | |
89 | that are already supported. If you are completely stuck, I suggest you | |
13934ef4 | 90 | post a message to perl5-porters, comp.lang.perl.misc or if you are really |
a0d0e21e LW |
91 | desperate to me. |
92 | ||
93 | Remember when you are making any changes that the return value from | |
94 | dl_load_file is used as a parameter in the dl_find_symbol | |
95 | function. Also the return value from find_symbol is used as a parameter | |
96 | to install_xsub. | |
97 | ||
98 | ||
99 | Dealing with Error Messages | |
100 | ============================ | |
101 | In order to make the handling of dynamic linking errors as generic as | |
102 | possible you should store any error messages associated with your | |
103 | implementation with the StoreError function. | |
104 | ||
105 | In the case of SunOS the function dlerror returns the error message | |
106 | associated with the last dynamic link error. As the SunOS dynamic | |
107 | linker functions dlopen & dlsym both return NULL on error every call | |
108 | to a SunOS dynamic link routine is coded like this | |
109 | ||
110 | RETVAL = dlopen(filename, 1) ; | |
111 | if (RETVAL == NULL) | |
112 | SaveError("%s",dlerror()) ; | |
113 | ||
114 | Note that SaveError() takes a printf format string. Use a "%s" as | |
115 | the first parameter if the error may contain and % characters. | |
116 | ||
117 | */ | |
118 | ||
119 | #include "EXTERN.h" | |
120 | #include "perl.h" | |
121 | #include "XSUB.h" | |
122 | ||
123 | #ifdef I_DLFCN | |
124 | #include <dlfcn.h> /* the dynamic linker include file for Sunos/Solaris */ | |
125 | #else | |
126 | #include <nlist.h> | |
127 | #include <link.h> | |
128 | #endif | |
129 | ||
8e07c86e AD |
130 | #ifndef RTLD_LAZY |
131 | # define RTLD_LAZY 1 /* Solaris 1 */ | |
132 | #endif | |
133 | ||
a0d0e21e | 134 | #ifndef HAS_DLERROR |
5d94fbed AD |
135 | # ifdef __NetBSD__ |
136 | # define dlerror() strerror(errno) | |
137 | # else | |
138 | # define dlerror() "Unknown error - dlerror() not implemented" | |
139 | # endif | |
a0d0e21e LW |
140 | #endif |
141 | ||
142 | ||
143 | #include "dlutils.c" /* SaveError() etc */ | |
144 | ||
145 | ||
146 | static void | |
cea2e8a9 | 147 | dl_private_init(pTHX) |
a0d0e21e | 148 | { |
cea2e8a9 | 149 | (void)dl_generic_private_init(aTHX); |
a0d0e21e LW |
150 | } |
151 | ||
152 | MODULE = DynaLoader PACKAGE = DynaLoader | |
153 | ||
154 | BOOT: | |
cea2e8a9 | 155 | (void)dl_private_init(aTHX); |
a0d0e21e LW |
156 | |
157 | ||
158 | void * | |
ff7f3c60 NIS |
159 | dl_load_file(filename, flags=0) |
160 | char * filename | |
161 | int flags | |
9d4ce9a5 | 162 | PREINIT: |
8e07c86e | 163 | int mode = RTLD_LAZY; |
9d4ce9a5 GS |
164 | CODE: |
165 | { | |
166 | #if defined(DLOPEN_WONT_DO_RELATIVE_PATHS) | |
167 | char pathbuf[PATH_MAX + 2]; | |
168 | if (*filename != '/' && strchr(filename, '/')) { | |
169 | if (getcwd(pathbuf, PATH_MAX - strlen(filename))) { | |
170 | strcat(pathbuf, "/"); | |
171 | strcat(pathbuf, filename); | |
172 | filename = pathbuf; | |
173 | } | |
174 | } | |
175 | #endif | |
8e07c86e AD |
176 | #ifdef RTLD_NOW |
177 | if (dl_nonlazy) | |
178 | mode = RTLD_NOW; | |
a0d0e21e | 179 | #endif |
ff7f3c60 NIS |
180 | if (flags & 0x01) |
181 | #ifdef RTLD_GLOBAL | |
182 | mode |= RTLD_GLOBAL; | |
183 | #else | |
cea2e8a9 | 184 | Perl_warn(aTHX_ "Can't make loaded symbols global on this platform while loading %s",filename); |
ff7f3c60 | 185 | #endif |
bf49b057 | 186 | DLDEBUG(1,PerlIO_printf(Perl_debug_log, "dl_load_file(%s,%x):\n", filename,flags)); |
a0d0e21e | 187 | RETVAL = dlopen(filename, mode) ; |
bf49b057 | 188 | DLDEBUG(2,PerlIO_printf(Perl_debug_log, " libref=%lx\n", (unsigned long) RETVAL)); |
a0d0e21e LW |
189 | ST(0) = sv_newmortal() ; |
190 | if (RETVAL == NULL) | |
cea2e8a9 | 191 | SaveError(aTHX_ "%s",dlerror()) ; |
a0d0e21e | 192 | else |
56431972 | 193 | sv_setiv( ST(0), PTR2IV(RETVAL)); |
9d4ce9a5 | 194 | } |
a0d0e21e | 195 | |
abb9e9dc GS |
196 | |
197 | int | |
198 | dl_unload_file(libref) | |
199 | void * libref | |
200 | CODE: | |
201 | DLDEBUG(1,PerlIO_printf(Perl_debug_log, "dl_unload_file(%lx):\n", libref)); | |
fa2bf5b6 | 202 | RETVAL = (dlclose(libref) == 0 ? 1 : 0); |
9c1391b6 | 203 | if (!RETVAL) |
fa2bf5b6 | 204 | SaveError(aTHX_ "%s", dlerror()) ; |
abb9e9dc GS |
205 | DLDEBUG(2,PerlIO_printf(Perl_debug_log, " retval = %d\n", RETVAL)); |
206 | OUTPUT: | |
207 | RETVAL | |
208 | ||
209 | ||
a0d0e21e LW |
210 | void * |
211 | dl_find_symbol(libhandle, symbolname) | |
212 | void * libhandle | |
213 | char * symbolname | |
214 | CODE: | |
215 | #ifdef DLSYM_NEEDS_UNDERSCORE | |
7a3f2258 | 216 | symbolname = Perl_form_nocontext("_%s", symbolname); |
a0d0e21e | 217 | #endif |
bf49b057 | 218 | DLDEBUG(2, PerlIO_printf(Perl_debug_log, |
46fc3d4c | 219 | "dl_find_symbol(handle=%lx, symbol=%s)\n", |
220 | (unsigned long) libhandle, symbolname)); | |
a0d0e21e | 221 | RETVAL = dlsym(libhandle, symbolname); |
bf49b057 | 222 | DLDEBUG(2, PerlIO_printf(Perl_debug_log, |
46fc3d4c | 223 | " symbolref = %lx\n", (unsigned long) RETVAL)); |
a0d0e21e LW |
224 | ST(0) = sv_newmortal() ; |
225 | if (RETVAL == NULL) | |
cea2e8a9 | 226 | SaveError(aTHX_ "%s",dlerror()) ; |
a0d0e21e | 227 | else |
56431972 | 228 | sv_setiv( ST(0), PTR2IV(RETVAL)); |
a0d0e21e LW |
229 | |
230 | ||
231 | void | |
232 | dl_undef_symbols() | |
233 | PPCODE: | |
234 | ||
235 | ||
236 | ||
237 | # These functions should not need changing on any platform: | |
238 | ||
239 | void | |
240 | dl_install_xsub(perl_name, symref, filename="$Package") | |
241 | char * perl_name | |
242 | void * symref | |
243 | char * filename | |
244 | CODE: | |
bf49b057 | 245 | DLDEBUG(2,PerlIO_printf(Perl_debug_log, "dl_install_xsub(name=%s, symref=%lx)\n", |
248e2fea | 246 | perl_name, (unsigned long) symref)); |
cea2e8a9 GS |
247 | ST(0) = sv_2mortal(newRV((SV*)newXS(perl_name, |
248 | (void(*)(pTHX_ CV *))symref, | |
249 | filename))); | |
a0d0e21e LW |
250 | |
251 | ||
252 | char * | |
253 | dl_error() | |
254 | CODE: | |
255 | RETVAL = LastError ; | |
256 | OUTPUT: | |
257 | RETVAL | |
258 | ||
259 | # end. |