| 1 | /* Plugin control for the GNU linker. |
| 2 | Copyright 2010, 2011 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of the GNU Binutils. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 3 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| 19 | MA 02110-1301, USA. */ |
| 20 | |
| 21 | #include "sysdep.h" |
| 22 | #include "libiberty.h" |
| 23 | #include "bfd.h" |
| 24 | #include "bfdlink.h" |
| 25 | #include "bfdver.h" |
| 26 | #include "ld.h" |
| 27 | #include "ldmain.h" |
| 28 | #include "ldmisc.h" |
| 29 | #include "ldexp.h" |
| 30 | #include "ldlang.h" |
| 31 | #include "ldfile.h" |
| 32 | #include "plugin.h" |
| 33 | #include "plugin-api.h" |
| 34 | #include "elf-bfd.h" |
| 35 | #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) |
| 36 | #include <Windows.h> |
| 37 | #endif |
| 38 | |
| 39 | /* The suffix to append to the name of the real (claimed) object file |
| 40 | when generating a dummy BFD to hold the IR symbols sent from the |
| 41 | plugin. */ |
| 42 | #define IRONLY_SUFFIX ".ironly\004" |
| 43 | |
| 44 | /* This is sizeof an array of chars, not sizeof a const char *. We |
| 45 | also have to avoid inadvertently counting the trailing NUL. */ |
| 46 | #define IRONLY_SUFFIX_LEN (sizeof (IRONLY_SUFFIX) - 1) |
| 47 | |
| 48 | /* Stores a single argument passed to a plugin. */ |
| 49 | typedef struct plugin_arg |
| 50 | { |
| 51 | struct plugin_arg *next; |
| 52 | const char *arg; |
| 53 | } plugin_arg_t; |
| 54 | |
| 55 | /* Holds all details of a single plugin. */ |
| 56 | typedef struct plugin |
| 57 | { |
| 58 | /* Next on the list of plugins, or NULL at end of chain. */ |
| 59 | struct plugin *next; |
| 60 | /* The argument string given to --plugin. */ |
| 61 | const char *name; |
| 62 | /* The shared library handle returned by dlopen. */ |
| 63 | void *dlhandle; |
| 64 | /* The list of argument string given to --plugin-opt. */ |
| 65 | plugin_arg_t *args; |
| 66 | /* Number of args in the list, for convenience. */ |
| 67 | size_t n_args; |
| 68 | /* The plugin's event handlers. */ |
| 69 | ld_plugin_claim_file_handler claim_file_handler; |
| 70 | ld_plugin_all_symbols_read_handler all_symbols_read_handler; |
| 71 | ld_plugin_cleanup_handler cleanup_handler; |
| 72 | /* TRUE if the cleanup handlers have been called. */ |
| 73 | bfd_boolean cleanup_done; |
| 74 | } plugin_t; |
| 75 | |
| 76 | /* The master list of all plugins. */ |
| 77 | static plugin_t *plugins_list = NULL; |
| 78 | |
| 79 | /* We keep a tail pointer for easy linking on the end. */ |
| 80 | static plugin_t **plugins_tail_chain_ptr = &plugins_list; |
| 81 | |
| 82 | /* The last plugin added to the list, for receiving args. */ |
| 83 | static plugin_t *last_plugin = NULL; |
| 84 | |
| 85 | /* The tail of the arg chain of the last plugin added to the list. */ |
| 86 | static plugin_arg_t **last_plugin_args_tail_chain_ptr = NULL; |
| 87 | |
| 88 | /* The plugin which is currently having a callback executed. */ |
| 89 | static plugin_t *called_plugin = NULL; |
| 90 | |
| 91 | /* Last plugin to cause an error, if any. */ |
| 92 | static const char *error_plugin = NULL; |
| 93 | |
| 94 | /* A hash table that records symbols referenced by non-IR files. Used |
| 95 | at get_symbols time to determine whether any prevailing defs from |
| 96 | IR files are referenced only from other IR files, so tthat we can |
| 97 | we can distinguish the LDPR_PREVAILING_DEF and LDPR_PREVAILING_DEF_IRONLY |
| 98 | cases when establishing symbol resolutions. */ |
| 99 | static struct bfd_hash_table *non_ironly_hash = NULL; |
| 100 | |
| 101 | /* Set at all symbols read time, to avoid recursively offering the plugin |
| 102 | its own newly-added input files and libs to claim. */ |
| 103 | static bfd_boolean no_more_claiming = FALSE; |
| 104 | |
| 105 | /* If the --allow-multiple-definition command-line option is active, we |
| 106 | have to disable it so that BFD always calls our hook, and simulate the |
| 107 | effect (when not resolving IR vs. real symbols) ourselves by ensuring |
| 108 | TRUE is returned from the hook. */ |
| 109 | static bfd_boolean plugin_cached_allow_multiple_defs = FALSE; |
| 110 | |
| 111 | /* List of tags to set in the constant leading part of the tv array. */ |
| 112 | static const enum ld_plugin_tag tv_header_tags[] = |
| 113 | { |
| 114 | LDPT_MESSAGE, |
| 115 | LDPT_API_VERSION, |
| 116 | LDPT_GNU_LD_VERSION, |
| 117 | LDPT_LINKER_OUTPUT, |
| 118 | LDPT_OUTPUT_NAME, |
| 119 | LDPT_REGISTER_CLAIM_FILE_HOOK, |
| 120 | LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK, |
| 121 | LDPT_REGISTER_CLEANUP_HOOK, |
| 122 | LDPT_ADD_SYMBOLS, |
| 123 | LDPT_GET_INPUT_FILE, |
| 124 | LDPT_RELEASE_INPUT_FILE, |
| 125 | LDPT_GET_SYMBOLS, |
| 126 | LDPT_ADD_INPUT_FILE, |
| 127 | LDPT_ADD_INPUT_LIBRARY, |
| 128 | LDPT_SET_EXTRA_LIBRARY_PATH |
| 129 | }; |
| 130 | |
| 131 | /* How many entries in the constant leading part of the tv array. */ |
| 132 | static const size_t tv_header_size = ARRAY_SIZE (tv_header_tags); |
| 133 | |
| 134 | #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) |
| 135 | |
| 136 | #define RTLD_NOW 0 /* Dummy value. */ |
| 137 | |
| 138 | static void * |
| 139 | dlopen (const char *file, int mode ATTRIBUTE_UNUSED) |
| 140 | { |
| 141 | return LoadLibrary (file); |
| 142 | } |
| 143 | |
| 144 | static void * |
| 145 | dlsym (void *handle, const char *name) |
| 146 | { |
| 147 | return GetProcAddress (handle, name); |
| 148 | } |
| 149 | |
| 150 | static int |
| 151 | dlclose (void *handle) |
| 152 | { |
| 153 | FreeLibrary (handle); |
| 154 | return 0; |
| 155 | } |
| 156 | |
| 157 | #endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H) */ |
| 158 | |
| 159 | /* Helper function for exiting with error status. */ |
| 160 | static int |
| 161 | set_plugin_error (const char *plugin) |
| 162 | { |
| 163 | error_plugin = plugin; |
| 164 | return -1; |
| 165 | } |
| 166 | |
| 167 | /* Test if an error occurred. */ |
| 168 | static bfd_boolean |
| 169 | plugin_error_p (void) |
| 170 | { |
| 171 | return error_plugin != NULL; |
| 172 | } |
| 173 | |
| 174 | /* Return name of plugin which caused an error if any. */ |
| 175 | const char * |
| 176 | plugin_error_plugin (void) |
| 177 | { |
| 178 | return error_plugin ? error_plugin : _("<no plugin>"); |
| 179 | } |
| 180 | |
| 181 | /* Handle -plugin arg: find and load plugin, or return error. */ |
| 182 | int |
| 183 | plugin_opt_plugin (const char *plugin) |
| 184 | { |
| 185 | plugin_t *newplug; |
| 186 | |
| 187 | newplug = xmalloc (sizeof *newplug); |
| 188 | memset (newplug, 0, sizeof *newplug); |
| 189 | newplug->name = plugin; |
| 190 | newplug->dlhandle = dlopen (plugin, RTLD_NOW); |
| 191 | if (!newplug->dlhandle) |
| 192 | return set_plugin_error (plugin); |
| 193 | |
| 194 | /* Chain on end, so when we run list it is in command-line order. */ |
| 195 | *plugins_tail_chain_ptr = newplug; |
| 196 | plugins_tail_chain_ptr = &newplug->next; |
| 197 | |
| 198 | /* Record it as current plugin for receiving args. */ |
| 199 | last_plugin = newplug; |
| 200 | last_plugin_args_tail_chain_ptr = &newplug->args; |
| 201 | return 0; |
| 202 | } |
| 203 | |
| 204 | /* Accumulate option arguments for last-loaded plugin, or return |
| 205 | error if none. */ |
| 206 | int |
| 207 | plugin_opt_plugin_arg (const char *arg) |
| 208 | { |
| 209 | plugin_arg_t *newarg; |
| 210 | |
| 211 | if (!last_plugin) |
| 212 | return set_plugin_error (_("<no plugin>")); |
| 213 | |
| 214 | newarg = xmalloc (sizeof *newarg); |
| 215 | newarg->arg = arg; |
| 216 | newarg->next = NULL; |
| 217 | |
| 218 | /* Chain on end to preserve command-line order. */ |
| 219 | *last_plugin_args_tail_chain_ptr = newarg; |
| 220 | last_plugin_args_tail_chain_ptr = &newarg->next; |
| 221 | last_plugin->n_args++; |
| 222 | return 0; |
| 223 | } |
| 224 | |
| 225 | /* Create a dummy BFD. */ |
| 226 | bfd * |
| 227 | plugin_get_ir_dummy_bfd (const char *name, bfd *srctemplate) |
| 228 | { |
| 229 | asection *sec; |
| 230 | bfd *abfd; |
| 231 | |
| 232 | bfd_use_reserved_id = 1; |
| 233 | abfd = bfd_create (concat (name, IRONLY_SUFFIX, (const char *)NULL), |
| 234 | srctemplate); |
| 235 | bfd_set_arch_info (abfd, bfd_get_arch_info (srctemplate)); |
| 236 | bfd_make_writable (abfd); |
| 237 | bfd_copy_private_bfd_data (srctemplate, abfd); |
| 238 | bfd_set_gp_size (abfd, bfd_get_gp_size (abfd)); |
| 239 | /* Create a minimal set of sections to own the symbols. */ |
| 240 | sec = bfd_make_section_old_way (abfd, ".text"); |
| 241 | bfd_set_section_flags (abfd, sec, |
| 242 | (SEC_CODE | SEC_HAS_CONTENTS | SEC_READONLY |
| 243 | | SEC_ALLOC | SEC_LOAD | SEC_KEEP)); |
| 244 | sec->output_section = sec; |
| 245 | sec->output_offset = 0; |
| 246 | return abfd; |
| 247 | } |
| 248 | |
| 249 | /* Check if the BFD passed in is an IR dummy object file. */ |
| 250 | static bfd_boolean |
| 251 | is_ir_dummy_bfd (const bfd *abfd) |
| 252 | { |
| 253 | size_t namlen; |
| 254 | |
| 255 | if (abfd == NULL) |
| 256 | return FALSE; |
| 257 | namlen = strlen (abfd->filename); |
| 258 | if (namlen < IRONLY_SUFFIX_LEN) |
| 259 | return FALSE; |
| 260 | return !strcmp (abfd->filename + namlen - IRONLY_SUFFIX_LEN, IRONLY_SUFFIX); |
| 261 | } |
| 262 | |
| 263 | /* Helpers to convert between BFD and GOLD symbol formats. */ |
| 264 | static enum ld_plugin_status |
| 265 | asymbol_from_plugin_symbol (bfd *abfd, asymbol *asym, |
| 266 | const struct ld_plugin_symbol *ldsym) |
| 267 | { |
| 268 | flagword flags = BSF_NO_FLAGS; |
| 269 | struct bfd_section *section; |
| 270 | |
| 271 | asym->the_bfd = abfd; |
| 272 | asym->name = (ldsym->version |
| 273 | ? concat (ldsym->name, "@", ldsym->version, NULL) |
| 274 | : ldsym->name); |
| 275 | asym->value = 0; |
| 276 | switch (ldsym->def) |
| 277 | { |
| 278 | case LDPK_WEAKDEF: |
| 279 | flags = BSF_WEAK; |
| 280 | /* FALLTHRU */ |
| 281 | case LDPK_DEF: |
| 282 | flags |= BSF_GLOBAL; |
| 283 | section = bfd_get_section_by_name (abfd, ".text"); |
| 284 | break; |
| 285 | |
| 286 | case LDPK_WEAKUNDEF: |
| 287 | flags = BSF_WEAK; |
| 288 | /* FALLTHRU */ |
| 289 | case LDPK_UNDEF: |
| 290 | section = bfd_und_section_ptr; |
| 291 | break; |
| 292 | |
| 293 | case LDPK_COMMON: |
| 294 | flags = BSF_GLOBAL; |
| 295 | section = bfd_com_section_ptr; |
| 296 | asym->value = ldsym->size; |
| 297 | /* For ELF targets, set alignment of common symbol to 1. */ |
| 298 | if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) |
| 299 | ((elf_symbol_type *) asym)->internal_elf_sym.st_value = 1; |
| 300 | break; |
| 301 | |
| 302 | default: |
| 303 | return LDPS_ERR; |
| 304 | } |
| 305 | asym->flags = flags; |
| 306 | asym->section = section; |
| 307 | |
| 308 | /* Visibility only applies on ELF targets. */ |
| 309 | if (bfd_get_flavour (abfd) == bfd_target_elf_flavour) |
| 310 | { |
| 311 | elf_symbol_type *elfsym = elf_symbol_from (abfd, asym); |
| 312 | unsigned char visibility; |
| 313 | |
| 314 | if (!elfsym) |
| 315 | einfo (_("%P%F: %s: non-ELF symbol in ELF BFD!\n"), asym->name); |
| 316 | switch (ldsym->visibility) |
| 317 | { |
| 318 | default: |
| 319 | einfo (_("%P%F: unknown ELF symbol visibility: %d!\n"), |
| 320 | ldsym->visibility); |
| 321 | case LDPV_DEFAULT: |
| 322 | visibility = STV_DEFAULT; |
| 323 | break; |
| 324 | case LDPV_PROTECTED: |
| 325 | visibility = STV_PROTECTED; |
| 326 | break; |
| 327 | case LDPV_INTERNAL: |
| 328 | visibility = STV_INTERNAL; |
| 329 | break; |
| 330 | case LDPV_HIDDEN: |
| 331 | visibility = STV_HIDDEN; |
| 332 | break; |
| 333 | } |
| 334 | elfsym->internal_elf_sym.st_other |
| 335 | = (visibility | (elfsym->internal_elf_sym.st_other |
| 336 | & ~ELF_ST_VISIBILITY (-1))); |
| 337 | } |
| 338 | |
| 339 | return LDPS_OK; |
| 340 | } |
| 341 | |
| 342 | /* Register a claim-file handler. */ |
| 343 | static enum ld_plugin_status |
| 344 | register_claim_file (ld_plugin_claim_file_handler handler) |
| 345 | { |
| 346 | ASSERT (called_plugin); |
| 347 | called_plugin->claim_file_handler = handler; |
| 348 | return LDPS_OK; |
| 349 | } |
| 350 | |
| 351 | /* Register an all-symbols-read handler. */ |
| 352 | static enum ld_plugin_status |
| 353 | register_all_symbols_read (ld_plugin_all_symbols_read_handler handler) |
| 354 | { |
| 355 | ASSERT (called_plugin); |
| 356 | called_plugin->all_symbols_read_handler = handler; |
| 357 | return LDPS_OK; |
| 358 | } |
| 359 | |
| 360 | /* Register a cleanup handler. */ |
| 361 | static enum ld_plugin_status |
| 362 | register_cleanup (ld_plugin_cleanup_handler handler) |
| 363 | { |
| 364 | ASSERT (called_plugin); |
| 365 | called_plugin->cleanup_handler = handler; |
| 366 | return LDPS_OK; |
| 367 | } |
| 368 | |
| 369 | /* Add symbols from a plugin-claimed input file. */ |
| 370 | static enum ld_plugin_status |
| 371 | add_symbols (void *handle, int nsyms, const struct ld_plugin_symbol *syms) |
| 372 | { |
| 373 | asymbol **symptrs; |
| 374 | bfd *abfd = handle; |
| 375 | int n; |
| 376 | ASSERT (called_plugin); |
| 377 | symptrs = xmalloc (nsyms * sizeof *symptrs); |
| 378 | for (n = 0; n < nsyms; n++) |
| 379 | { |
| 380 | enum ld_plugin_status rv; |
| 381 | asymbol *bfdsym = bfd_make_empty_symbol (abfd); |
| 382 | symptrs[n] = bfdsym; |
| 383 | rv = asymbol_from_plugin_symbol (abfd, bfdsym, syms + n); |
| 384 | if (rv != LDPS_OK) |
| 385 | return rv; |
| 386 | } |
| 387 | bfd_set_symtab (abfd, symptrs, nsyms); |
| 388 | return LDPS_OK; |
| 389 | } |
| 390 | |
| 391 | /* Get the input file information with an open (possibly re-opened) |
| 392 | file descriptor. */ |
| 393 | static enum ld_plugin_status |
| 394 | get_input_file (const void *handle, struct ld_plugin_input_file *file) |
| 395 | { |
| 396 | ASSERT (called_plugin); |
| 397 | handle = handle; |
| 398 | file = file; |
| 399 | return LDPS_ERR; |
| 400 | } |
| 401 | |
| 402 | /* Release the input file. */ |
| 403 | static enum ld_plugin_status |
| 404 | release_input_file (const void *handle) |
| 405 | { |
| 406 | ASSERT (called_plugin); |
| 407 | handle = handle; |
| 408 | return LDPS_ERR; |
| 409 | } |
| 410 | |
| 411 | /* Return TRUE if a defined symbol might be reachable from outside the |
| 412 | universe of claimed objects. */ |
| 413 | static inline bfd_boolean |
| 414 | is_visible_from_outside (struct ld_plugin_symbol *lsym, asection *section, |
| 415 | struct bfd_link_hash_entry *blhe) |
| 416 | { |
| 417 | /* Section's owner may be NULL if it is the absolute |
| 418 | section, fortunately is_ir_dummy_bfd handles that. */ |
| 419 | if (!is_ir_dummy_bfd (section->owner)) |
| 420 | return TRUE; |
| 421 | if (link_info.relocatable) |
| 422 | return TRUE; |
| 423 | if (link_info.export_dynamic || link_info.shared) |
| 424 | { |
| 425 | /* Only ELF symbols really have visibility. */ |
| 426 | if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour) |
| 427 | { |
| 428 | struct elf_link_hash_entry *el = (struct elf_link_hash_entry *)blhe; |
| 429 | int vis = ELF_ST_VISIBILITY (el->other); |
| 430 | return vis == STV_DEFAULT || vis == STV_PROTECTED; |
| 431 | } |
| 432 | /* On non-ELF targets, we can safely make inferences by considering |
| 433 | what visibility the plugin would have liked to apply when it first |
| 434 | sent us the symbol. During ELF symbol processing, visibility only |
| 435 | ever becomes more restrictive, not less, when symbols are merged, |
| 436 | so this is a conservative estimate; it may give false positives, |
| 437 | declaring something visible from outside when it in fact would |
| 438 | not have been, but this will only lead to missed optimisation |
| 439 | opportunities during LTRANS at worst; it will not give false |
| 440 | negatives, which can lead to the disastrous conclusion that the |
| 441 | related symbol is IRONLY. (See GCC PR46319 for an example.) */ |
| 442 | return (lsym->visibility == LDPV_DEFAULT |
| 443 | || lsym->visibility == LDPV_PROTECTED); |
| 444 | } |
| 445 | return FALSE; |
| 446 | } |
| 447 | |
| 448 | /* Get the symbol resolution info for a plugin-claimed input file. */ |
| 449 | static enum ld_plugin_status |
| 450 | get_symbols (const void *handle, int nsyms, struct ld_plugin_symbol *syms) |
| 451 | { |
| 452 | const bfd *abfd = handle; |
| 453 | int n; |
| 454 | ASSERT (called_plugin); |
| 455 | for (n = 0; n < nsyms; n++) |
| 456 | { |
| 457 | struct bfd_link_hash_entry *blhe; |
| 458 | bfd_boolean ironly; |
| 459 | asection *owner_sec; |
| 460 | |
| 461 | blhe = bfd_link_hash_lookup (link_info.hash, syms[n].name, |
| 462 | FALSE, FALSE, TRUE); |
| 463 | if (!blhe) |
| 464 | { |
| 465 | syms[n].resolution = LDPR_UNKNOWN; |
| 466 | continue; |
| 467 | } |
| 468 | |
| 469 | /* Determine resolution from blhe type and symbol's original type. */ |
| 470 | if (blhe->type == bfd_link_hash_undefined |
| 471 | || blhe->type == bfd_link_hash_undefweak) |
| 472 | { |
| 473 | syms[n].resolution = LDPR_UNDEF; |
| 474 | continue; |
| 475 | } |
| 476 | if (blhe->type != bfd_link_hash_defined |
| 477 | && blhe->type != bfd_link_hash_defweak |
| 478 | && blhe->type != bfd_link_hash_common) |
| 479 | { |
| 480 | /* We should not have a new, indirect or warning symbol here. */ |
| 481 | einfo ("%P%F: %s: plugin symbol table corrupt (sym type %d)\n", |
| 482 | called_plugin->name, blhe->type); |
| 483 | } |
| 484 | |
| 485 | /* Find out which section owns the symbol. Since it's not undef, |
| 486 | it must have an owner; if it's not a common symbol, both defs |
| 487 | and weakdefs keep it in the same place. */ |
| 488 | owner_sec = (blhe->type == bfd_link_hash_common) |
| 489 | ? blhe->u.c.p->section |
| 490 | : blhe->u.def.section; |
| 491 | |
| 492 | /* We need to know if the sym is referenced from non-IR files. Or |
| 493 | even potentially-referenced, perhaps in a future final link if |
| 494 | this is a partial one, perhaps dynamically at load-time if the |
| 495 | symbol is externally visible. */ |
| 496 | ironly = !is_visible_from_outside (&syms[n], owner_sec, blhe) |
| 497 | && !bfd_hash_lookup (non_ironly_hash, syms[n].name, FALSE, FALSE); |
| 498 | |
| 499 | /* If it was originally undefined or common, then it has been |
| 500 | resolved; determine how. */ |
| 501 | if (syms[n].def == LDPK_UNDEF |
| 502 | || syms[n].def == LDPK_WEAKUNDEF |
| 503 | || syms[n].def == LDPK_COMMON) |
| 504 | { |
| 505 | if (owner_sec->owner == link_info.output_bfd) |
| 506 | syms[n].resolution = LDPR_RESOLVED_EXEC; |
| 507 | else if (owner_sec->owner == abfd) |
| 508 | syms[n].resolution = (ironly |
| 509 | ? LDPR_PREVAILING_DEF_IRONLY |
| 510 | : LDPR_PREVAILING_DEF); |
| 511 | else if (is_ir_dummy_bfd (owner_sec->owner)) |
| 512 | syms[n].resolution = LDPR_RESOLVED_IR; |
| 513 | else if (owner_sec->owner != NULL |
| 514 | && (owner_sec->owner->flags & DYNAMIC) != 0) |
| 515 | syms[n].resolution = LDPR_RESOLVED_DYN; |
| 516 | else |
| 517 | syms[n].resolution = LDPR_RESOLVED_EXEC; |
| 518 | continue; |
| 519 | } |
| 520 | |
| 521 | /* Was originally def, or weakdef. Does it prevail? If the |
| 522 | owner is the original dummy bfd that supplied it, then this |
| 523 | is the definition that has prevailed. */ |
| 524 | if (owner_sec->owner == link_info.output_bfd) |
| 525 | syms[n].resolution = LDPR_PREEMPTED_REG; |
| 526 | else if (owner_sec->owner == abfd) |
| 527 | { |
| 528 | syms[n].resolution = (ironly |
| 529 | ? LDPR_PREVAILING_DEF_IRONLY |
| 530 | : LDPR_PREVAILING_DEF); |
| 531 | continue; |
| 532 | } |
| 533 | |
| 534 | /* Was originally def, weakdef, or common, but has been pre-empted. */ |
| 535 | syms[n].resolution = is_ir_dummy_bfd (owner_sec->owner) |
| 536 | ? LDPR_PREEMPTED_IR |
| 537 | : LDPR_PREEMPTED_REG; |
| 538 | } |
| 539 | return LDPS_OK; |
| 540 | } |
| 541 | |
| 542 | /* Add a new (real) input file generated by a plugin. */ |
| 543 | static enum ld_plugin_status |
| 544 | add_input_file (const char *pathname) |
| 545 | { |
| 546 | ASSERT (called_plugin); |
| 547 | if (!lang_add_input_file (xstrdup (pathname), lang_input_file_is_file_enum, |
| 548 | NULL)) |
| 549 | return LDPS_ERR; |
| 550 | return LDPS_OK; |
| 551 | } |
| 552 | |
| 553 | /* Add a new (real) library required by a plugin. */ |
| 554 | static enum ld_plugin_status |
| 555 | add_input_library (const char *pathname) |
| 556 | { |
| 557 | ASSERT (called_plugin); |
| 558 | if (!lang_add_input_file (xstrdup (pathname), lang_input_file_is_l_enum, |
| 559 | NULL)) |
| 560 | return LDPS_ERR; |
| 561 | return LDPS_OK; |
| 562 | } |
| 563 | |
| 564 | /* Set the extra library path to be used by libraries added via |
| 565 | add_input_library. */ |
| 566 | static enum ld_plugin_status |
| 567 | set_extra_library_path (const char *path) |
| 568 | { |
| 569 | ASSERT (called_plugin); |
| 570 | ldfile_add_library_path (xstrdup (path), FALSE); |
| 571 | return LDPS_OK; |
| 572 | } |
| 573 | |
| 574 | /* Issue a diagnostic message from a plugin. */ |
| 575 | static enum ld_plugin_status |
| 576 | message (int level, const char *format, ...) |
| 577 | { |
| 578 | va_list args; |
| 579 | va_start (args, format); |
| 580 | |
| 581 | switch (level) |
| 582 | { |
| 583 | case LDPL_INFO: |
| 584 | vfinfo (stdout, format, args, FALSE); |
| 585 | putchar ('\n'); |
| 586 | break; |
| 587 | case LDPL_WARNING: |
| 588 | vfinfo (stdout, format, args, TRUE); |
| 589 | putchar ('\n'); |
| 590 | break; |
| 591 | case LDPL_FATAL: |
| 592 | case LDPL_ERROR: |
| 593 | default: |
| 594 | { |
| 595 | char *newfmt = ACONCAT ((level == LDPL_FATAL |
| 596 | ? "%P%F: " : "%P%X: ", |
| 597 | format, "\n", NULL)); |
| 598 | fflush (stdout); |
| 599 | vfinfo (stderr, newfmt, args, TRUE); |
| 600 | fflush (stderr); |
| 601 | } |
| 602 | break; |
| 603 | } |
| 604 | |
| 605 | va_end (args); |
| 606 | return LDPS_OK; |
| 607 | } |
| 608 | |
| 609 | /* Helper to size leading part of tv array and set it up. */ |
| 610 | static size_t |
| 611 | set_tv_header (struct ld_plugin_tv *tv) |
| 612 | { |
| 613 | size_t i; |
| 614 | |
| 615 | /* Version info. */ |
| 616 | static const unsigned int major = (unsigned)(BFD_VERSION / 100000000UL); |
| 617 | static const unsigned int minor = (unsigned)(BFD_VERSION / 1000000UL) % 100; |
| 618 | |
| 619 | if (!tv) |
| 620 | return tv_header_size; |
| 621 | |
| 622 | for (i = 0; i < tv_header_size; i++) |
| 623 | { |
| 624 | tv[i].tv_tag = tv_header_tags[i]; |
| 625 | #define TVU(x) tv[i].tv_u.tv_ ## x |
| 626 | switch (tv[i].tv_tag) |
| 627 | { |
| 628 | case LDPT_MESSAGE: |
| 629 | TVU(message) = message; |
| 630 | break; |
| 631 | case LDPT_API_VERSION: |
| 632 | TVU(val) = LD_PLUGIN_API_VERSION; |
| 633 | break; |
| 634 | case LDPT_GNU_LD_VERSION: |
| 635 | TVU(val) = major * 100 + minor; |
| 636 | break; |
| 637 | case LDPT_LINKER_OUTPUT: |
| 638 | TVU(val) = (link_info.relocatable |
| 639 | ? LDPO_REL |
| 640 | : (link_info.shared ? LDPO_DYN : LDPO_EXEC)); |
| 641 | break; |
| 642 | case LDPT_OUTPUT_NAME: |
| 643 | TVU(string) = output_filename; |
| 644 | break; |
| 645 | case LDPT_REGISTER_CLAIM_FILE_HOOK: |
| 646 | TVU(register_claim_file) = register_claim_file; |
| 647 | break; |
| 648 | case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK: |
| 649 | TVU(register_all_symbols_read) = register_all_symbols_read; |
| 650 | break; |
| 651 | case LDPT_REGISTER_CLEANUP_HOOK: |
| 652 | TVU(register_cleanup) = register_cleanup; |
| 653 | break; |
| 654 | case LDPT_ADD_SYMBOLS: |
| 655 | TVU(add_symbols) = add_symbols; |
| 656 | break; |
| 657 | case LDPT_GET_INPUT_FILE: |
| 658 | TVU(get_input_file) = get_input_file; |
| 659 | break; |
| 660 | case LDPT_RELEASE_INPUT_FILE: |
| 661 | TVU(release_input_file) = release_input_file; |
| 662 | break; |
| 663 | case LDPT_GET_SYMBOLS: |
| 664 | TVU(get_symbols) = get_symbols; |
| 665 | break; |
| 666 | case LDPT_ADD_INPUT_FILE: |
| 667 | TVU(add_input_file) = add_input_file; |
| 668 | break; |
| 669 | case LDPT_ADD_INPUT_LIBRARY: |
| 670 | TVU(add_input_library) = add_input_library; |
| 671 | break; |
| 672 | case LDPT_SET_EXTRA_LIBRARY_PATH: |
| 673 | TVU(set_extra_library_path) = set_extra_library_path; |
| 674 | break; |
| 675 | default: |
| 676 | /* Added a new entry to the array without adding |
| 677 | a new case to set up its value is a bug. */ |
| 678 | FAIL (); |
| 679 | } |
| 680 | #undef TVU |
| 681 | } |
| 682 | return tv_header_size; |
| 683 | } |
| 684 | |
| 685 | /* Append the per-plugin args list and trailing LDPT_NULL to tv. */ |
| 686 | static void |
| 687 | set_tv_plugin_args (plugin_t *plugin, struct ld_plugin_tv *tv) |
| 688 | { |
| 689 | plugin_arg_t *arg = plugin->args; |
| 690 | while (arg) |
| 691 | { |
| 692 | tv->tv_tag = LDPT_OPTION; |
| 693 | tv->tv_u.tv_string = arg->arg; |
| 694 | arg = arg->next; |
| 695 | tv++; |
| 696 | } |
| 697 | tv->tv_tag = LDPT_NULL; |
| 698 | tv->tv_u.tv_val = 0; |
| 699 | } |
| 700 | |
| 701 | /* Return true if any plugins are active this run. Only valid |
| 702 | after options have been processed. */ |
| 703 | bfd_boolean |
| 704 | plugin_active_plugins_p (void) |
| 705 | { |
| 706 | return plugins_list != NULL; |
| 707 | } |
| 708 | |
| 709 | /* Load up and initialise all plugins after argument parsing. */ |
| 710 | int |
| 711 | plugin_load_plugins (void) |
| 712 | { |
| 713 | struct ld_plugin_tv *my_tv; |
| 714 | unsigned int max_args = 0; |
| 715 | plugin_t *curplug = plugins_list; |
| 716 | |
| 717 | /* If there are no plugins, we need do nothing this run. */ |
| 718 | if (!curplug) |
| 719 | return 0; |
| 720 | |
| 721 | /* First pass over plugins to find max # args needed so that we |
| 722 | can size and allocate the tv array. */ |
| 723 | while (curplug) |
| 724 | { |
| 725 | if (curplug->n_args > max_args) |
| 726 | max_args = curplug->n_args; |
| 727 | curplug = curplug->next; |
| 728 | } |
| 729 | |
| 730 | /* Allocate tv array and initialise constant part. */ |
| 731 | my_tv = xmalloc ((max_args + 1 + tv_header_size) * sizeof *my_tv); |
| 732 | set_tv_header (my_tv); |
| 733 | |
| 734 | /* Pass over plugins again, activating them. */ |
| 735 | curplug = plugins_list; |
| 736 | while (curplug) |
| 737 | { |
| 738 | enum ld_plugin_status rv; |
| 739 | ld_plugin_onload onloadfn = dlsym (curplug->dlhandle, "onload"); |
| 740 | if (!onloadfn) |
| 741 | onloadfn = dlsym (curplug->dlhandle, "_onload"); |
| 742 | if (!onloadfn) |
| 743 | return set_plugin_error (curplug->name); |
| 744 | set_tv_plugin_args (curplug, &my_tv[tv_header_size]); |
| 745 | called_plugin = curplug; |
| 746 | rv = (*onloadfn) (my_tv); |
| 747 | called_plugin = NULL; |
| 748 | if (rv != LDPS_OK) |
| 749 | return set_plugin_error (curplug->name); |
| 750 | curplug = curplug->next; |
| 751 | } |
| 752 | |
| 753 | /* Since plugin(s) inited ok, assume they're going to want symbol |
| 754 | resolutions, which needs us to track which symbols are referenced |
| 755 | by non-IR files using the linker's notice callback. */ |
| 756 | link_info.notice_all = TRUE; |
| 757 | |
| 758 | return 0; |
| 759 | } |
| 760 | |
| 761 | /* Call 'claim file' hook for all plugins. */ |
| 762 | int |
| 763 | plugin_call_claim_file (const struct ld_plugin_input_file *file, int *claimed) |
| 764 | { |
| 765 | plugin_t *curplug = plugins_list; |
| 766 | *claimed = FALSE; |
| 767 | if (no_more_claiming) |
| 768 | return 0; |
| 769 | while (curplug && !*claimed) |
| 770 | { |
| 771 | if (curplug->claim_file_handler) |
| 772 | { |
| 773 | enum ld_plugin_status rv; |
| 774 | called_plugin = curplug; |
| 775 | rv = (*curplug->claim_file_handler) (file, claimed); |
| 776 | called_plugin = NULL; |
| 777 | if (rv != LDPS_OK) |
| 778 | set_plugin_error (curplug->name); |
| 779 | } |
| 780 | curplug = curplug->next; |
| 781 | } |
| 782 | return plugin_error_p () ? -1 : 0; |
| 783 | } |
| 784 | |
| 785 | /* Call 'all symbols read' hook for all plugins. */ |
| 786 | int |
| 787 | plugin_call_all_symbols_read (void) |
| 788 | { |
| 789 | plugin_t *curplug = plugins_list; |
| 790 | |
| 791 | /* Disable any further file-claiming. */ |
| 792 | no_more_claiming = TRUE; |
| 793 | |
| 794 | /* If --allow-multiple-definition is in effect, we need to disable it, |
| 795 | as the plugin infrastructure relies on the multiple_definition |
| 796 | callback to swap out the dummy IR-only BFDs for new real ones |
| 797 | when it starts opening the files added during this callback. */ |
| 798 | plugin_cached_allow_multiple_defs = link_info.allow_multiple_definition; |
| 799 | link_info.allow_multiple_definition = FALSE; |
| 800 | |
| 801 | while (curplug) |
| 802 | { |
| 803 | if (curplug->all_symbols_read_handler) |
| 804 | { |
| 805 | enum ld_plugin_status rv; |
| 806 | called_plugin = curplug; |
| 807 | rv = (*curplug->all_symbols_read_handler) (); |
| 808 | called_plugin = NULL; |
| 809 | if (rv != LDPS_OK) |
| 810 | set_plugin_error (curplug->name); |
| 811 | } |
| 812 | curplug = curplug->next; |
| 813 | } |
| 814 | return plugin_error_p () ? -1 : 0; |
| 815 | } |
| 816 | |
| 817 | /* Call 'cleanup' hook for all plugins at exit. */ |
| 818 | void |
| 819 | plugin_call_cleanup (void) |
| 820 | { |
| 821 | plugin_t *curplug = plugins_list; |
| 822 | while (curplug) |
| 823 | { |
| 824 | if (curplug->cleanup_handler && !curplug->cleanup_done) |
| 825 | { |
| 826 | enum ld_plugin_status rv; |
| 827 | curplug->cleanup_done = TRUE; |
| 828 | called_plugin = curplug; |
| 829 | rv = (*curplug->cleanup_handler) (); |
| 830 | called_plugin = NULL; |
| 831 | if (rv != LDPS_OK) |
| 832 | set_plugin_error (curplug->name); |
| 833 | dlclose (curplug->dlhandle); |
| 834 | } |
| 835 | curplug = curplug->next; |
| 836 | } |
| 837 | if (plugin_error_p ()) |
| 838 | info_msg (_("%P: %s: error in plugin cleanup (ignored)\n"), |
| 839 | plugin_error_plugin ()); |
| 840 | } |
| 841 | |
| 842 | /* Lazily init the non_ironly hash table. */ |
| 843 | static void |
| 844 | init_non_ironly_hash (void) |
| 845 | { |
| 846 | if (non_ironly_hash == NULL) |
| 847 | { |
| 848 | non_ironly_hash = |
| 849 | (struct bfd_hash_table *) xmalloc (sizeof (struct bfd_hash_table)); |
| 850 | if (!bfd_hash_table_init_n (non_ironly_hash, |
| 851 | bfd_hash_newfunc, |
| 852 | sizeof (struct bfd_hash_entry), |
| 853 | 61)) |
| 854 | einfo (_("%P%F: bfd_hash_table_init failed: %E\n")); |
| 855 | } |
| 856 | } |
| 857 | |
| 858 | /* To determine which symbols should be resolved LDPR_PREVAILING_DEF |
| 859 | and which LDPR_PREVAILING_DEF_IRONLY, we notice all the symbols as |
| 860 | the linker adds them to the linker hash table. If we see a symbol |
| 861 | being referenced from a non-IR file, we add it to the non_ironly hash |
| 862 | table. If we can't find it there at get_symbols time, we know that |
| 863 | it was referenced only by IR files. We have to notice_all symbols, |
| 864 | because we won't necessarily know until later which ones will be |
| 865 | contributed by IR files. */ |
| 866 | bfd_boolean |
| 867 | plugin_notice (struct bfd_link_info *info ATTRIBUTE_UNUSED, |
| 868 | const char *name, bfd *abfd, |
| 869 | asection *section, bfd_vma value ATTRIBUTE_UNUSED) |
| 870 | { |
| 871 | bfd_boolean is_ref = bfd_is_und_section (section); |
| 872 | bfd_boolean is_dummy = is_ir_dummy_bfd (abfd); |
| 873 | init_non_ironly_hash (); |
| 874 | /* We only care about refs, not defs, indicated by section pointing |
| 875 | to the undefined section (according to the bfd linker notice callback |
| 876 | interface definition). */ |
| 877 | if (is_ref && !is_dummy) |
| 878 | { |
| 879 | /* This is a ref from a non-IR file, so note the ref'd symbol |
| 880 | in the non-IR-only hash. */ |
| 881 | if (!bfd_hash_lookup (non_ironly_hash, name, TRUE, TRUE)) |
| 882 | einfo (_("%P%X: %s: hash table failure adding symbol %s\n"), |
| 883 | abfd->filename, name); |
| 884 | } |
| 885 | else if (!is_ref && is_dummy) |
| 886 | { |
| 887 | /* No further processing since this is a def from an IR dummy BFD. */ |
| 888 | return FALSE; |
| 889 | } |
| 890 | |
| 891 | /* Continue with cref/nocrossref/trace-sym processing. */ |
| 892 | return TRUE; |
| 893 | } |
| 894 | |
| 895 | /* When we add new object files to the link at all symbols read time, |
| 896 | these contain the real code and symbols generated from the IR files, |
| 897 | and so duplicate all the definitions already supplied by the dummy |
| 898 | IR-only BFDs that we created at claim files time. We use the linker's |
| 899 | multiple-definitions callback hook to fix up the clash, discarding |
| 900 | the symbol from the IR-only BFD in favour of the symbol from the |
| 901 | real BFD. We return true if this was not-really-a-clash because |
| 902 | we've fixed it up, or anyway if --allow-multiple-definition was in |
| 903 | effect (before we disabled it to ensure we got called back). */ |
| 904 | bfd_boolean |
| 905 | plugin_multiple_definition (struct bfd_link_info *info, const char *name, |
| 906 | bfd *obfd, asection *osec ATTRIBUTE_UNUSED, |
| 907 | bfd_vma oval ATTRIBUTE_UNUSED, |
| 908 | bfd *nbfd, asection *nsec, bfd_vma nval) |
| 909 | { |
| 910 | if (is_ir_dummy_bfd (obfd)) |
| 911 | { |
| 912 | struct bfd_link_hash_entry *blhe |
| 913 | = bfd_link_hash_lookup (info->hash, name, FALSE, FALSE, FALSE); |
| 914 | if (!blhe) |
| 915 | einfo (_("%P%X: %s: can't find IR symbol '%s'\n"), nbfd->filename, |
| 916 | name); |
| 917 | else if (blhe->type != bfd_link_hash_defined) |
| 918 | einfo (_("%P%x: %s: bad IR symbol type %d\n"), name, blhe->type); |
| 919 | /* Replace it with new details. */ |
| 920 | blhe->u.def.section = nsec; |
| 921 | blhe->u.def.value = nval; |
| 922 | return TRUE; |
| 923 | } |
| 924 | return plugin_cached_allow_multiple_defs; |
| 925 | } |