| 1 | /* dynl.c - dynamic linking |
| 2 | * |
| 3 | * Copyright (C) 1990, 91, 92, 93, 94, 95, 96, 97, 98, 99, 2000 Free Software Foundation, Inc. |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2, or (at your option) |
| 8 | * any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this software; see the file COPYING. If not, write to |
| 17 | * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, |
| 18 | * Boston, MA 02111-1307 USA |
| 19 | * |
| 20 | * As a special exception, the Free Software Foundation gives permission |
| 21 | * for additional uses of the text contained in its release of GUILE. |
| 22 | * |
| 23 | * The exception is that, if you link the GUILE library with other files |
| 24 | * to produce an executable, this does not by itself cause the |
| 25 | * resulting executable to be covered by the GNU General Public License. |
| 26 | * Your use of that executable is in no way restricted on account of |
| 27 | * linking the GUILE library code into it. |
| 28 | * |
| 29 | * This exception does not however invalidate any other reasons why |
| 30 | * the executable file might be covered by the GNU General Public License. |
| 31 | * |
| 32 | * This exception applies only to the code released by the |
| 33 | * Free Software Foundation under the name GUILE. If you copy |
| 34 | * code from other Free Software Foundation releases into a copy of |
| 35 | * GUILE, as the General Public License permits, the exception does |
| 36 | * not apply to the code that you add in this way. To avoid misleading |
| 37 | * anyone as to the status of such modified files, you must delete |
| 38 | * this exception notice from them. |
| 39 | * |
| 40 | * If you write modifications of your own for GUILE, it is your choice |
| 41 | * whether to permit this exception to apply to your modifications. |
| 42 | * If you do not wish that, delete this exception notice. */ |
| 43 | |
| 44 | /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999, |
| 45 | gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */ |
| 46 | |
| 47 | |
| 48 | /* "dynl.c" dynamically link&load object files. |
| 49 | Author: Aubrey Jaffer |
| 50 | Modified for libguile by Marius Vollmer */ |
| 51 | |
| 52 | #if 0 /* Disabled until we know for sure that it isn't needed */ |
| 53 | /* XXX - This is only here to drag in a definition of __eprintf. This |
| 54 | is needed for proper operation of dynamic linking. The real |
| 55 | solution would probably be a shared libgcc. */ |
| 56 | |
| 57 | #undef NDEBUG |
| 58 | #include <assert.h> |
| 59 | |
| 60 | static void |
| 61 | maybe_drag_in_eprintf () |
| 62 | { |
| 63 | assert (!maybe_drag_in_eprintf); |
| 64 | } |
| 65 | #endif |
| 66 | |
| 67 | #include <stdio.h> |
| 68 | #include <string.h> |
| 69 | |
| 70 | #include "libguile/_scm.h" |
| 71 | #include "libguile/dynl.h" |
| 72 | #include "libguile/smob.h" |
| 73 | #include "libguile/keywords.h" |
| 74 | #include "libguile/ports.h" |
| 75 | #include "libguile/strings.h" |
| 76 | |
| 77 | #include "libguile/validate.h" |
| 78 | |
| 79 | /* Create a new C argv array from a scheme list of strings. */ |
| 80 | /* Dirk:FIXME:: A quite similar function is implemented in posix.c */ |
| 81 | /* Dirk:FIXME:: In case of assertion errors, we get memory leaks */ |
| 82 | |
| 83 | /* Converting a list of SCM strings into a argv-style array. You must |
| 84 | have ints disabled for the whole lifetime of the created argv (from |
| 85 | before MAKE_ARGV_FROM_STRINGLIST until after |
| 86 | MUST_FREE_ARGV). Atleast this is was the documentation for |
| 87 | MAKARGVFROMSTRS says, it isn't really used that way. |
| 88 | |
| 89 | This code probably belongs into strings.c |
| 90 | (Dirk: IMO strings.c is not the right place.) */ |
| 91 | |
| 92 | static char ** |
| 93 | scm_make_argv_from_stringlist (SCM args,int *argcp,const char *subr,int argn) |
| 94 | { |
| 95 | char **argv; |
| 96 | int argc; |
| 97 | int i; |
| 98 | |
| 99 | argc = scm_ilength (args); |
| 100 | SCM_ASSERT (argc >= 0, args, argn, subr); |
| 101 | argv = (char **) scm_must_malloc ((argc + 1) * sizeof (char *), subr); |
| 102 | for (i = 0; !SCM_NULLP (args); args = SCM_CDR (args), ++i) { |
| 103 | SCM arg = SCM_CAR (args); |
| 104 | size_t len; |
| 105 | char *dst; |
| 106 | char *src; |
| 107 | |
| 108 | SCM_ASSERT (SCM_STRINGP (arg), args, argn, subr); |
| 109 | len = SCM_STRING_LENGTH (arg); |
| 110 | src = SCM_STRING_CHARS (arg); |
| 111 | dst = (char *) scm_must_malloc (len + 1, subr); |
| 112 | memcpy (dst, src, len); |
| 113 | dst[len] = 0; |
| 114 | argv[i] = dst; |
| 115 | } |
| 116 | |
| 117 | if (argcp) |
| 118 | *argcp = argc; |
| 119 | argv[argc] = 0; |
| 120 | return argv; |
| 121 | } |
| 122 | |
| 123 | static void |
| 124 | scm_must_free_argv(char **argv) |
| 125 | { |
| 126 | char **av = argv; |
| 127 | while (*av) |
| 128 | free (*(av++)); |
| 129 | free (argv); |
| 130 | } |
| 131 | |
| 132 | /* Module registry |
| 133 | */ |
| 134 | |
| 135 | /* We can't use SCM objects here. One should be able to call |
| 136 | SCM_REGISTER_MODULE from a C++ constructor for a static |
| 137 | object. This happens before main and thus before libguile is |
| 138 | initialized. */ |
| 139 | |
| 140 | struct moddata { |
| 141 | struct moddata *link; |
| 142 | char *module_name; |
| 143 | void *init_func; |
| 144 | }; |
| 145 | |
| 146 | static struct moddata *registered_mods = NULL; |
| 147 | |
| 148 | void |
| 149 | scm_register_module_xxx (char *module_name, void *init_func) |
| 150 | { |
| 151 | struct moddata *md; |
| 152 | |
| 153 | /* XXX - should we (and can we) DEFER_INTS here? */ |
| 154 | |
| 155 | for (md = registered_mods; md; md = md->link) |
| 156 | if (!strcmp (md->module_name, module_name)) |
| 157 | { |
| 158 | md->init_func = init_func; |
| 159 | return; |
| 160 | } |
| 161 | |
| 162 | md = (struct moddata *) malloc (sizeof (struct moddata)); |
| 163 | if (md == NULL) |
| 164 | { |
| 165 | fprintf (stderr, |
| 166 | "guile: can't register module (%s): not enough memory", |
| 167 | module_name); |
| 168 | return; |
| 169 | } |
| 170 | |
| 171 | md->module_name = module_name; |
| 172 | md->init_func = init_func; |
| 173 | md->link = registered_mods; |
| 174 | registered_mods = md; |
| 175 | } |
| 176 | |
| 177 | SCM_DEFINE (scm_registered_modules, "c-registered-modules", 0, 0, 0, |
| 178 | (), |
| 179 | "Return a list of the object code modules that have been imported into\n" |
| 180 | "the current Guile process. Each element of the list is a pair whose\n" |
| 181 | "car is the name of the module, and whose cdr is the function handle\n" |
| 182 | "for that module's initializer function. The name is the string that\n" |
| 183 | "has been passed to scm_register_module_xxx.") |
| 184 | #define FUNC_NAME s_scm_registered_modules |
| 185 | { |
| 186 | SCM res; |
| 187 | struct moddata *md; |
| 188 | |
| 189 | res = SCM_EOL; |
| 190 | for (md = registered_mods; md; md = md->link) |
| 191 | res = scm_cons (scm_cons (scm_makfrom0str (md->module_name), |
| 192 | scm_ulong2num ((unsigned long) md->init_func)), |
| 193 | res); |
| 194 | return res; |
| 195 | } |
| 196 | #undef FUNC_NAME |
| 197 | |
| 198 | SCM_DEFINE (scm_clear_registered_modules, "c-clear-registered-modules", 0, 0, 0, |
| 199 | (), |
| 200 | "Destroy the list of modules registered with the current Guile process.\n" |
| 201 | "The return value is unspecified. @strong{Warning:} this function does\n" |
| 202 | "not actually unlink or deallocate these modules, but only destroys the\n" |
| 203 | "records of which modules have been loaded. It should therefore be used\n" |
| 204 | "only by module bookkeeping operations.") |
| 205 | #define FUNC_NAME s_scm_clear_registered_modules |
| 206 | { |
| 207 | struct moddata *md1, *md2; |
| 208 | |
| 209 | SCM_DEFER_INTS; |
| 210 | |
| 211 | for (md1 = registered_mods; md1; md1 = md2) |
| 212 | { |
| 213 | md2 = md1->link; |
| 214 | free (md1); |
| 215 | } |
| 216 | registered_mods = NULL; |
| 217 | |
| 218 | SCM_ALLOW_INTS; |
| 219 | return SCM_UNSPECIFIED; |
| 220 | } |
| 221 | #undef FUNC_NAME |
| 222 | |
| 223 | /* Dispatch to the system dependent files |
| 224 | * |
| 225 | * They define some static functions. These functions are called with |
| 226 | * deferred interrupts. When they want to throw errors, they are |
| 227 | * expected to insert a SCM_ALLOW_INTS before doing the throw. It |
| 228 | * might work to throw an error while interrupts are deferred (because |
| 229 | * they will be unconditionally allowed the next time a SCM_ALLOW_INTS |
| 230 | * is executed, SCM_DEFER_INTS and SCM_ALLOW_INTS do not nest). |
| 231 | */ |
| 232 | |
| 233 | #ifdef DYNAMIC_LINKING |
| 234 | |
| 235 | #include "libltdl/ltdl.h" |
| 236 | |
| 237 | static void * |
| 238 | sysdep_dynl_link (const char *fname, const char *subr) |
| 239 | { |
| 240 | lt_dlhandle handle; |
| 241 | handle = lt_dlopenext (fname); |
| 242 | if (NULL == handle) |
| 243 | { |
| 244 | SCM fn; |
| 245 | SCM msg; |
| 246 | |
| 247 | SCM_ALLOW_INTS; |
| 248 | fn = scm_makfrom0str (fname); |
| 249 | msg = scm_makfrom0str (lt_dlerror ()); |
| 250 | scm_misc_error (subr, "file: ~S, message: ~S", SCM_LIST2 (fn, msg)); |
| 251 | } |
| 252 | return (void *) handle; |
| 253 | } |
| 254 | |
| 255 | static void |
| 256 | sysdep_dynl_unlink (void *handle, const char *subr) |
| 257 | { |
| 258 | if (lt_dlclose ((lt_dlhandle) handle)) |
| 259 | { |
| 260 | SCM_ALLOW_INTS; |
| 261 | scm_misc_error (subr, (char *) lt_dlerror (), SCM_EOL); |
| 262 | } |
| 263 | } |
| 264 | |
| 265 | static void * |
| 266 | sysdep_dynl_func (const char *symb, void *handle, const char *subr) |
| 267 | { |
| 268 | void *fptr; |
| 269 | |
| 270 | fptr = lt_dlsym ((lt_dlhandle) handle, symb); |
| 271 | if (!fptr) |
| 272 | { |
| 273 | SCM_ALLOW_INTS; |
| 274 | scm_misc_error (subr, (char *) lt_dlerror (), SCM_EOL); |
| 275 | } |
| 276 | return fptr; |
| 277 | } |
| 278 | |
| 279 | static void |
| 280 | sysdep_dynl_init () |
| 281 | { |
| 282 | lt_dlinit (); |
| 283 | } |
| 284 | |
| 285 | #else |
| 286 | |
| 287 | /* no dynamic linking available, throw errors. */ |
| 288 | |
| 289 | static void |
| 290 | sysdep_dynl_init (void) |
| 291 | { |
| 292 | } |
| 293 | |
| 294 | static void |
| 295 | no_dynl_error (const char *subr) |
| 296 | { |
| 297 | SCM_ALLOW_INTS; |
| 298 | scm_misc_error (subr, "dynamic linking not available", SCM_EOL); |
| 299 | } |
| 300 | |
| 301 | static void * |
| 302 | sysdep_dynl_link (const char *filename, const char *subr) |
| 303 | { |
| 304 | no_dynl_error (subr); |
| 305 | return NULL; |
| 306 | } |
| 307 | |
| 308 | static void |
| 309 | sysdep_dynl_unlink (void *handle, |
| 310 | const char *subr) |
| 311 | { |
| 312 | no_dynl_error (subr); |
| 313 | } |
| 314 | |
| 315 | static void * |
| 316 | sysdep_dynl_func (const char *symbol, |
| 317 | void *handle, |
| 318 | const char *subr) |
| 319 | { |
| 320 | no_dynl_error (subr); |
| 321 | return NULL; |
| 322 | } |
| 323 | |
| 324 | #endif |
| 325 | |
| 326 | scm_bits_t scm_tc16_dynamic_obj; |
| 327 | |
| 328 | #define DYNL_FILENAME(x) (SCM_CELL_OBJECT_1 (x)) |
| 329 | #define DYNL_HANDLE(x) ((void *) SCM_CELL_WORD_2 (x)) |
| 330 | #define SET_DYNL_HANDLE(x, v) (SCM_SET_CELL_WORD_2 ((x), (v))) |
| 331 | |
| 332 | |
| 333 | static SCM |
| 334 | dynl_obj_mark (SCM ptr) |
| 335 | { |
| 336 | return DYNL_FILENAME (ptr); |
| 337 | } |
| 338 | |
| 339 | |
| 340 | static int |
| 341 | dynl_obj_print (SCM exp, SCM port, scm_print_state *pstate) |
| 342 | { |
| 343 | scm_puts ("#<dynamic-object ", port); |
| 344 | scm_iprin1 (DYNL_FILENAME (exp), port, pstate); |
| 345 | if (DYNL_HANDLE (exp) == NULL) |
| 346 | scm_puts (" (unlinked)", port); |
| 347 | scm_putc ('>', port); |
| 348 | return 1; |
| 349 | } |
| 350 | |
| 351 | |
| 352 | SCM_DEFINE (scm_dynamic_link, "dynamic-link", 1, 0, 0, |
| 353 | (SCM filename), |
| 354 | "Open the dynamic library called @var{filename}. A library\n" |
| 355 | "handle representing the opened library is returned; this handle\n" |
| 356 | "should be used as the @var{dobj} argument to the following\n" |
| 357 | "functions.") |
| 358 | #define FUNC_NAME s_scm_dynamic_link |
| 359 | { |
| 360 | void *handle; |
| 361 | |
| 362 | SCM_VALIDATE_STRING (1, filename); |
| 363 | SCM_STRING_COERCE_0TERMINATION_X (filename); |
| 364 | handle = sysdep_dynl_link (SCM_STRING_CHARS (filename), FUNC_NAME); |
| 365 | SCM_RETURN_NEWSMOB2 (scm_tc16_dynamic_obj, SCM_UNPACK (filename), handle); |
| 366 | } |
| 367 | #undef FUNC_NAME |
| 368 | |
| 369 | |
| 370 | SCM_DEFINE (scm_dynamic_object_p, "dynamic-object?", 1, 0, 0, |
| 371 | (SCM obj), |
| 372 | "Return @code{#t} if @var{obj} is a dynamic library handle, or @code{#f}\n" |
| 373 | "otherwise.") |
| 374 | #define FUNC_NAME s_scm_dynamic_object_p |
| 375 | { |
| 376 | return SCM_BOOL (SCM_TYP16_PREDICATE (scm_tc16_dynamic_obj, obj)); |
| 377 | } |
| 378 | #undef FUNC_NAME |
| 379 | |
| 380 | |
| 381 | SCM_DEFINE (scm_dynamic_unlink, "dynamic-unlink", 1, 0, 0, |
| 382 | (SCM dobj), |
| 383 | "Unlink the indicated object file from the application. The\n" |
| 384 | "argument @var{dobj} must have been obtained by a call to\n" |
| 385 | "@code{dynamic-link}. After @code{dynamic-unlink} has been\n" |
| 386 | "called on @var{dobj}, its content is no longer accessible.") |
| 387 | #define FUNC_NAME s_scm_dynamic_unlink |
| 388 | { |
| 389 | /*fixme* GC-problem */ |
| 390 | SCM_VALIDATE_SMOB (SCM_ARG1, dobj, dynamic_obj); |
| 391 | if (DYNL_HANDLE (dobj) == NULL) { |
| 392 | SCM_MISC_ERROR ("Already unlinked: ~S", dobj); |
| 393 | } else { |
| 394 | SCM_DEFER_INTS; |
| 395 | sysdep_dynl_unlink (DYNL_HANDLE (dobj), FUNC_NAME); |
| 396 | SET_DYNL_HANDLE (dobj, NULL); |
| 397 | SCM_ALLOW_INTS; |
| 398 | return SCM_UNSPECIFIED; |
| 399 | } |
| 400 | } |
| 401 | #undef FUNC_NAME |
| 402 | |
| 403 | |
| 404 | SCM_DEFINE (scm_dynamic_func, "dynamic-func", 2, 0, 0, |
| 405 | (SCM name, SCM dobj), |
| 406 | "Search the dynamic object @var{dobj} for the C function\n" |
| 407 | "indicated by the string @var{name} and return some Scheme\n" |
| 408 | "handle that can later be used with @code{dynamic-call} to\n" |
| 409 | "actually call the function.\n\n" |
| 410 | "Regardless whether your C compiler prepends an underscore @samp{_} to\n" |
| 411 | "the global names in a program, you should @strong{not} include this\n" |
| 412 | "underscore in @var{function}. Guile knows whether the underscore is\n" |
| 413 | "needed or not and will add it when necessary.") |
| 414 | #define FUNC_NAME s_scm_dynamic_func |
| 415 | { |
| 416 | /* The returned handle is formed by casting the address of the function to a |
| 417 | * long value and converting this to a scheme number |
| 418 | */ |
| 419 | |
| 420 | void (*func) (); |
| 421 | |
| 422 | SCM_VALIDATE_STRING (1, name); |
| 423 | /*fixme* GC-problem */ |
| 424 | SCM_VALIDATE_SMOB (SCM_ARG2, dobj, dynamic_obj); |
| 425 | if (DYNL_HANDLE (dobj) == NULL) { |
| 426 | SCM_MISC_ERROR ("Already unlinked: ~S", dobj); |
| 427 | } else { |
| 428 | char *chars; |
| 429 | |
| 430 | SCM_DEFER_INTS; |
| 431 | SCM_STRING_COERCE_0TERMINATION_X (name); |
| 432 | chars = SCM_STRING_CHARS (name); |
| 433 | func = (void (*) ()) sysdep_dynl_func (chars, DYNL_HANDLE (dobj), FUNC_NAME); |
| 434 | SCM_ALLOW_INTS; |
| 435 | return scm_ulong2num ((unsigned long) func); |
| 436 | } |
| 437 | } |
| 438 | #undef FUNC_NAME |
| 439 | |
| 440 | |
| 441 | SCM_DEFINE (scm_dynamic_call, "dynamic-call", 2, 0, 0, |
| 442 | (SCM func, SCM dobj), |
| 443 | "Call the C function indicated by @var{func} and @var{dobj}.\n" |
| 444 | "The function is passed no arguments and its return value is\n" |
| 445 | "ignored. When @var{function} is something returned by\n" |
| 446 | "@code{dynamic-func}, call that function and ignore @var{dobj}.\n" |
| 447 | "When @var{func} is a string , look it up in @var{dynobj}; this\n" |
| 448 | "is equivalent to\n" |
| 449 | "@smallexample\n" |
| 450 | "(dynamic-call (dynamic-func @var{func} @var{dobj} #f))\n" |
| 451 | "@end smallexample\n\n" |
| 452 | "Interrupts are deferred while the C function is executing (with\n" |
| 453 | "@code{SCM_DEFER_INTS}/@code{SCM_ALLOW_INTS}).") |
| 454 | #define FUNC_NAME s_scm_dynamic_call |
| 455 | { |
| 456 | void (*fptr) (); |
| 457 | |
| 458 | if (SCM_STRINGP (func)) |
| 459 | func = scm_dynamic_func (func, dobj); |
| 460 | fptr = (void (*) ()) SCM_NUM2ULONG (1, func); |
| 461 | SCM_DEFER_INTS; |
| 462 | fptr (); |
| 463 | SCM_ALLOW_INTS; |
| 464 | return SCM_UNSPECIFIED; |
| 465 | } |
| 466 | #undef FUNC_NAME |
| 467 | |
| 468 | SCM_DEFINE (scm_dynamic_args_call, "dynamic-args-call", 3, 0, 0, |
| 469 | (SCM func, SCM dobj, SCM args), |
| 470 | "Call the C function indicated by @var{func} and @var{dobj},\n" |
| 471 | "just like @code{dynamic-call}, but pass it some arguments and\n" |
| 472 | "return its return value. The C function is expected to take\n" |
| 473 | "two arguments and return an @code{int}, just like @code{main}:\n" |
| 474 | "@smallexample\n" |
| 475 | "int c_func (int argc, char **argv);\n" |
| 476 | "@end smallexample\n\n" |
| 477 | "The parameter @var{args} must be a list of strings and is\n" |
| 478 | "converted into an array of @code{char *}. The array is passed\n" |
| 479 | "in @var{argv} and its size in @var{argc}. The return value is\n" |
| 480 | "converted to a Scheme number and returned from the call to\n" |
| 481 | "@code{dynamic-args-call}.") |
| 482 | #define FUNC_NAME s_scm_dynamic_args_call |
| 483 | { |
| 484 | int (*fptr) (int argc, char **argv); |
| 485 | int result, argc; |
| 486 | char **argv; |
| 487 | |
| 488 | if (SCM_STRINGP (func)) |
| 489 | func = scm_dynamic_func (func, dobj); |
| 490 | |
| 491 | fptr = (int (*) (int, char **)) SCM_NUM2ULONG (1, func); |
| 492 | SCM_DEFER_INTS; |
| 493 | argv = scm_make_argv_from_stringlist (args, &argc, FUNC_NAME, SCM_ARG3); |
| 494 | result = (*fptr) (argc, argv); |
| 495 | scm_must_free_argv (argv); |
| 496 | SCM_ALLOW_INTS; |
| 497 | |
| 498 | return SCM_MAKINUM (0L + result); |
| 499 | } |
| 500 | #undef FUNC_NAME |
| 501 | |
| 502 | void |
| 503 | scm_init_dynamic_linking () |
| 504 | { |
| 505 | scm_tc16_dynamic_obj = scm_make_smob_type ("dynamic-object", 0); |
| 506 | scm_set_smob_mark (scm_tc16_dynamic_obj, dynl_obj_mark); |
| 507 | scm_set_smob_print (scm_tc16_dynamic_obj, dynl_obj_print); |
| 508 | sysdep_dynl_init (); |
| 509 | #ifndef SCM_MAGIC_SNARFER |
| 510 | #include "libguile/dynl.x" |
| 511 | #endif |
| 512 | } |
| 513 | |
| 514 | /* |
| 515 | Local Variables: |
| 516 | c-file-style: "gnu" |
| 517 | End: |
| 518 | */ |