ld/plugin.c

   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 #include "libbfd.h"
  36 #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)
  37 #include <windows.h>
  38 #endif
  39
  40 /* Report plugin symbols.  */
  41 bfd_boolean report_plugin_symbols;
  42
  43 /* The suffix to append to the name of the real (claimed) object file
  44    when generating a dummy BFD to hold the IR symbols sent from the
  45    plugin.  For cosmetic use only; appears in maps, crefs etc.  */
  46 #define IRONLY_SUFFIX " (symbol from plugin)"
  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 /* State of linker "notice" interface before we poked at it.  */
  95 static bfd_boolean orig_notice_all;
  96
  97 /* Original linker callbacks, and the plugin version.  */
  98 static const struct bfd_link_callbacks *orig_callbacks;
  99 static struct bfd_link_callbacks plugin_callbacks;
 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 bfd_boolean no_more_claiming = FALSE;
 104
 105 /* List of tags to set in the constant leading part of the tv array. */
 106 static const enum ld_plugin_tag tv_header_tags[] =
 107 {
 108   LDPT_MESSAGE,
 109   LDPT_API_VERSION,
 110   LDPT_GNU_LD_VERSION,
 111   LDPT_LINKER_OUTPUT,
 112   LDPT_OUTPUT_NAME,
 113   LDPT_REGISTER_CLAIM_FILE_HOOK,
 114   LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK,
 115   LDPT_REGISTER_CLEANUP_HOOK,
 116   LDPT_ADD_SYMBOLS,
 117   LDPT_GET_INPUT_FILE,
 118   LDPT_RELEASE_INPUT_FILE,
 119   LDPT_GET_SYMBOLS,
 120   LDPT_ADD_INPUT_FILE,
 121   LDPT_ADD_INPUT_LIBRARY,
 122   LDPT_SET_EXTRA_LIBRARY_PATH
 123 };
 124
 125 /* How many entries in the constant leading part of the tv array.  */
 126 static const size_t tv_header_size = ARRAY_SIZE (tv_header_tags);
 127
 128 /* Forward references.  */
 129 static bfd_boolean plugin_notice (struct bfd_link_info *,
 130                                   struct bfd_link_hash_entry *, bfd *,
 131                                   asection *, bfd_vma, flagword, const char *);
 132
 133 #if !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)
 134
 135 #define RTLD_NOW 0      /* Dummy value.  */
 136
 137 static void *
 138 dlopen (const char *file, int mode ATTRIBUTE_UNUSED)
 139 {
 140   return LoadLibrary (file);
 141 }
 142
 143 static void *
 144 dlsym (void *handle, const char *name)
 145 {
 146   return GetProcAddress (handle, name);
 147 }
 148
 149 static int
 150 dlclose (void *handle)
 151 {
 152   FreeLibrary (handle);
 153   return 0;
 154 }
 155
 156 #endif /* !defined (HAVE_DLFCN_H) && defined (HAVE_WINDOWS_H)  */
 157
 158 /* Helper function for exiting with error status.  */
 159 static int
 160 set_plugin_error (const char *plugin)
 161 {
 162   error_plugin = plugin;
 163   return -1;
 164 }
 165
 166 /* Test if an error occurred.  */
 167 static bfd_boolean
 168 plugin_error_p (void)
 169 {
 170   return error_plugin != NULL;
 171 }
 172
 173 /* Return name of plugin which caused an error if any.  */
 174 const char *
 175 plugin_error_plugin (void)
 176 {
 177   return error_plugin ? error_plugin : _("<no plugin>");
 178 }
 179
 180 /* Handle -plugin arg: find and load plugin, or return error.  */
 181 int
 182 plugin_opt_plugin (const char *plugin)
 183 {
 184   plugin_t *newplug;
 185
 186   newplug = xmalloc (sizeof *newplug);
 187   memset (newplug, 0, sizeof *newplug);
 188   newplug->name = plugin;
 189   newplug->dlhandle = dlopen (plugin, RTLD_NOW);
 190   if (!newplug->dlhandle)
 191     return set_plugin_error (plugin);
 192
 193   /* Chain on end, so when we run list it is in command-line order.  */
 194   *plugins_tail_chain_ptr = newplug;
 195   plugins_tail_chain_ptr = &newplug->next;
 196
 197   /* Record it as current plugin for receiving args.  */
 198   last_plugin = newplug;
 199   last_plugin_args_tail_chain_ptr = &newplug->args;
 200   return 0;
 201 }
 202
 203 /* Accumulate option arguments for last-loaded plugin, or return
 204    error if none.  */
 205 int
 206 plugin_opt_plugin_arg (const char *arg)
 207 {
 208   plugin_arg_t *newarg;
 209
 210   if (!last_plugin)
 211     return set_plugin_error (_("<no plugin>"));
 212
 213   newarg = xmalloc (sizeof *newarg);
 214   newarg->arg = arg;
 215   newarg->next = NULL;
 216
 217   /* Chain on end to preserve command-line order.  */
 218   *last_plugin_args_tail_chain_ptr = newarg;
 219   last_plugin_args_tail_chain_ptr = &newarg->next;
 220   last_plugin->n_args++;
 221   return 0;
 222 }
 223
 224 /* Create a dummy BFD.  */
 225 bfd *
 226 plugin_get_ir_dummy_bfd (const char *name, bfd *srctemplate)
 227 {
 228   bfd *abfd;
 229
 230   bfd_use_reserved_id = 1;
 231   abfd = bfd_create (concat (name, IRONLY_SUFFIX, (const char *) NULL),
 232                      srctemplate);
 233   if (abfd != NULL)
 234     {
 235       abfd->flags |= BFD_LINKER_CREATED | BFD_PLUGIN;
 236       bfd_set_arch_info (abfd, bfd_get_arch_info (srctemplate));
 237       bfd_set_gp_size (abfd, bfd_get_gp_size (srctemplate));
 238       if (bfd_make_writable (abfd)
 239           && bfd_copy_private_bfd_data (srctemplate, abfd))
 240         {
 241           flagword flags;
 242
 243           /* Create sections to own the symbols.  */
 244           flags = (SEC_CODE | SEC_HAS_CONTENTS | SEC_READONLY
 245                    | SEC_ALLOC | SEC_LOAD | SEC_KEEP | SEC_EXCLUDE);
 246           if (bfd_make_section_anyway_with_flags (abfd, ".text", flags))
 247             return abfd;
 248         }
 249     }
 250   einfo (_("could not create dummy IR bfd: %F%E\n"));
 251   return NULL;
 252 }
 253
 254 /* Check if the BFD passed in is an IR dummy object file.  */
 255 static bfd_boolean
 256 is_ir_dummy_bfd (const bfd *abfd)
 257 {
 258   /* ABFD can sometimes legitimately be NULL, e.g. when called from one
 259      of the linker callbacks for a symbol in the *ABS* or *UND* sections.
 260      Likewise, the usrdata field may be NULL if ABFD was added by the
 261      backend without a corresponding input statement, as happens e.g.
 262      when processing DT_NEEDED dependencies.  */
 263   return (abfd
 264           && abfd->usrdata
 265           && ((lang_input_statement_type *)(abfd->usrdata))->claimed);
 266 }
 267
 268 /* Helpers to convert between BFD and GOLD symbol formats.  */
 269 static enum ld_plugin_status
 270 asymbol_from_plugin_symbol (bfd *abfd, asymbol *asym,
 271                             const struct ld_plugin_symbol *ldsym)
 272 {
 273   flagword flags = BSF_NO_FLAGS;
 274   struct bfd_section *section;
 275
 276   asym->the_bfd = abfd;
 277   asym->name = (ldsym->version
 278                 ? concat (ldsym->name, "@", ldsym->version, (const char *) NULL)
 279                 : ldsym->name);
 280   asym->value = 0;
 281   switch (ldsym->def)
 282     {
 283     case LDPK_WEAKDEF:
 284       flags = BSF_WEAK;
 285       /* FALLTHRU */
 286     case LDPK_DEF:
 287       flags |= BSF_GLOBAL;
 288       section = bfd_get_section_by_name (abfd, ".text");
 289       break;
 290
 291     case LDPK_WEAKUNDEF:
 292       flags = BSF_WEAK;
 293       /* FALLTHRU */
 294     case LDPK_UNDEF:
 295       section = bfd_und_section_ptr;
 296       break;
 297
 298     case LDPK_COMMON:
 299       flags = BSF_GLOBAL;
 300       section = bfd_com_section_ptr;
 301       asym->value = ldsym->size;
 302       /* For ELF targets, set alignment of common symbol to 1.  */
 303       if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
 304         {
 305           ((elf_symbol_type *) asym)->internal_elf_sym.st_shndx = SHN_COMMON;
 306           ((elf_symbol_type *) asym)->internal_elf_sym.st_value = 1;
 307         }
 308       break;
 309
 310     default:
 311       return LDPS_ERR;
 312     }
 313   asym->flags = flags;
 314   asym->section = section;
 315
 316   /* Visibility only applies on ELF targets.  */
 317   if (bfd_get_flavour (abfd) == bfd_target_elf_flavour)
 318     {
 319       elf_symbol_type *elfsym = elf_symbol_from (abfd, asym);
 320       unsigned char visibility;
 321
 322       if (!elfsym)
 323         einfo (_("%P%F: %s: non-ELF symbol in ELF BFD!\n"), asym->name);
 324       switch (ldsym->visibility)
 325         {
 326         default:
 327           einfo (_("%P%F: unknown ELF symbol visibility: %d!\n"),
 328                  ldsym->visibility);
 329         case LDPV_DEFAULT:
 330           visibility = STV_DEFAULT;
 331           break;
 332         case LDPV_PROTECTED:
 333           visibility = STV_PROTECTED;
 334           break;
 335         case LDPV_INTERNAL:
 336           visibility = STV_INTERNAL;
 337           break;
 338         case LDPV_HIDDEN:
 339           visibility = STV_HIDDEN;
 340           break;
 341         }
 342       elfsym->internal_elf_sym.st_other
 343         = (visibility | (elfsym->internal_elf_sym.st_other
 344                          & ~ELF_ST_VISIBILITY (-1)));
 345     }
 346
 347   return LDPS_OK;
 348 }
 349
 350 /* Register a claim-file handler.  */
 351 static enum ld_plugin_status
 352 register_claim_file (ld_plugin_claim_file_handler handler)
 353 {
 354   ASSERT (called_plugin);
 355   called_plugin->claim_file_handler = handler;
 356   return LDPS_OK;
 357 }
 358
 359 /* Register an all-symbols-read handler.  */
 360 static enum ld_plugin_status
 361 register_all_symbols_read (ld_plugin_all_symbols_read_handler handler)
 362 {
 363   ASSERT (called_plugin);
 364   called_plugin->all_symbols_read_handler = handler;
 365   return LDPS_OK;
 366 }
 367
 368 /* Register a cleanup handler.  */
 369 static enum ld_plugin_status
 370 register_cleanup (ld_plugin_cleanup_handler handler)
 371 {
 372   ASSERT (called_plugin);
 373   called_plugin->cleanup_handler = handler;
 374   return LDPS_OK;
 375 }
 376
 377 /* Add symbols from a plugin-claimed input file.  */
 378 static enum ld_plugin_status
 379 add_symbols (void *handle, int nsyms, const struct ld_plugin_symbol *syms)
 380 {
 381   asymbol **symptrs;
 382   bfd *abfd = handle;
 383   int n, k;
 384
 385   ASSERT (called_plugin);
 386   symptrs = xmalloc (nsyms * sizeof *symptrs);
 387   for (n = 0, k = 0; n < nsyms; n++)
 388     {
 389       enum ld_plugin_status rv;
 390       asymbol *bfdsym;
 391
 392       if (syms[n].comdat_key)
 393         {
 394           struct already_linked linked;
 395           linked.comdat_key = xstrdup (syms[n].comdat_key);
 396           linked.u.abfd = abfd;
 397           if (bfd_section_already_linked (abfd, &linked, &link_info))
 398             continue;
 399         }
 400       bfdsym = bfd_make_empty_symbol (abfd);
 401       symptrs[k++] = bfdsym;
 402       rv = asymbol_from_plugin_symbol (abfd, bfdsym, syms + n);
 403       if (rv != LDPS_OK)
 404         return rv;
 405     }
 406   bfd_set_symtab (abfd, symptrs, k);
 407   return LDPS_OK;
 408 }
 409
 410 /* Get the input file information with an open (possibly re-opened)
 411    file descriptor.  */
 412 static enum ld_plugin_status
 413 get_input_file (const void *handle, struct ld_plugin_input_file *file)
 414 {
 415   ASSERT (called_plugin);
 416   handle = handle;
 417   file = file;
 418   return LDPS_ERR;
 419 }
 420
 421 /* Release the input file.  */
 422 static enum ld_plugin_status
 423 release_input_file (const void *handle)
 424 {
 425   ASSERT (called_plugin);
 426   handle = handle;
 427   return LDPS_ERR;
 428 }
 429
 430 /* Return TRUE if a defined symbol might be reachable from outside the
 431    universe of claimed objects.  */
 432 static inline bfd_boolean
 433 is_visible_from_outside (struct ld_plugin_symbol *lsym, asection *section,
 434                          struct bfd_link_hash_entry *blhe)
 435 {
 436   struct bfd_sym_chain *sym;
 437
 438   /* Section's owner may be NULL if it is the absolute
 439      section, fortunately is_ir_dummy_bfd handles that.  */
 440   if (!is_ir_dummy_bfd (section->owner))
 441     return TRUE;
 442   if (link_info.relocatable)
 443     return TRUE;
 444   if (link_info.export_dynamic || link_info.shared)
 445     {
 446       /* Only ELF symbols really have visibility.  */
 447       if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour)
 448         {
 449           struct elf_link_hash_entry *el = (struct elf_link_hash_entry *)blhe;
 450           int vis = ELF_ST_VISIBILITY (el->other);
 451           return vis == STV_DEFAULT || vis == STV_PROTECTED;
 452         }
 453       /* On non-ELF targets, we can safely make inferences by considering
 454          what visibility the plugin would have liked to apply when it first
 455          sent us the symbol.  During ELF symbol processing, visibility only
 456          ever becomes more restrictive, not less, when symbols are merged,
 457          so this is a conservative estimate; it may give false positives,
 458          declaring something visible from outside when it in fact would
 459          not have been, but this will only lead to missed optimisation
 460          opportunities during LTRANS at worst; it will not give false
 461          negatives, which can lead to the disastrous conclusion that the
 462          related symbol is IRONLY.  (See GCC PR46319 for an example.)  */
 463       return (lsym->visibility == LDPV_DEFAULT
 464               || lsym->visibility == LDPV_PROTECTED);
 465     }
 466
 467   for (sym = &entry_symbol; sym != NULL; sym = sym->next)
 468     if (sym->name
 469         && strcmp (sym->name, blhe->root.string) == 0)
 470       return TRUE;
 471
 472   return FALSE;
 473 }
 474
 475 /* Get the symbol resolution info for a plugin-claimed input file.  */
 476 static enum ld_plugin_status
 477 get_symbols (const void *handle, int nsyms, struct ld_plugin_symbol *syms)
 478 {
 479   const bfd *abfd = handle;
 480   int n;
 481   ASSERT (called_plugin);
 482   for (n = 0; n < nsyms; n++)
 483     {
 484       struct bfd_link_hash_entry *blhe;
 485       bfd_boolean ironly;
 486       asection *owner_sec;
 487       if (syms[n].def != LDPK_UNDEF)
 488         blhe = bfd_link_hash_lookup (link_info.hash, syms[n].name,
 489                                      FALSE, FALSE, TRUE);
 490       else
 491         blhe = bfd_wrapped_link_hash_lookup (link_info.output_bfd, &link_info,
 492                                              syms[n].name, FALSE, FALSE, TRUE);
 493       if (!blhe)
 494         {
 495           syms[n].resolution = LDPR_UNKNOWN;
 496           goto report_symbol;
 497         }
 498
 499       /* Determine resolution from blhe type and symbol's original type.  */
 500       if (blhe->type == bfd_link_hash_undefined
 501           || blhe->type == bfd_link_hash_undefweak)
 502         {
 503           syms[n].resolution = LDPR_UNDEF;
 504           goto report_symbol;
 505         }
 506       if (blhe->type != bfd_link_hash_defined
 507           && blhe->type != bfd_link_hash_defweak
 508           && blhe->type != bfd_link_hash_common)
 509         {
 510           /* We should not have a new, indirect or warning symbol here.  */
 511           einfo ("%P%F: %s: plugin symbol table corrupt (sym type %d)\n",
 512                  called_plugin->name, blhe->type);
 513         }
 514
 515       /* Find out which section owns the symbol.  Since it's not undef,
 516          it must have an owner; if it's not a common symbol, both defs
 517          and weakdefs keep it in the same place. */
 518       owner_sec = (blhe->type == bfd_link_hash_common
 519                    ? blhe->u.c.p->section
 520                    : blhe->u.def.section);
 521
 522       /* We need to know if the sym is referenced from non-IR files.  Or
 523          even potentially-referenced, perhaps in a future final link if
 524          this is a partial one, perhaps dynamically at load-time if the
 525          symbol is externally visible.  */
 526       ironly = !(blhe->non_ir_ref
 527                  || is_visible_from_outside (&syms[n], owner_sec, blhe));
 528
 529       /* If it was originally undefined or common, then it has been
 530          resolved; determine how.  */
 531       if (syms[n].def == LDPK_UNDEF
 532           || syms[n].def == LDPK_WEAKUNDEF
 533           || syms[n].def == LDPK_COMMON)
 534         {
 535           if (owner_sec->owner == link_info.output_bfd)
 536             syms[n].resolution = LDPR_RESOLVED_EXEC;
 537           else if (owner_sec->owner == abfd)
 538             syms[n].resolution = (ironly
 539                                   ? LDPR_PREVAILING_DEF_IRONLY
 540                                   : LDPR_PREVAILING_DEF);
 541           else if (is_ir_dummy_bfd (owner_sec->owner))
 542             syms[n].resolution = LDPR_RESOLVED_IR;
 543           else if (owner_sec->owner != NULL
 544                    && (owner_sec->owner->flags & DYNAMIC) != 0)
 545             syms[n].resolution =  LDPR_RESOLVED_DYN;
 546           else
 547             syms[n].resolution = LDPR_RESOLVED_EXEC;
 548           goto report_symbol;
 549         }
 550
 551       /* Was originally def, or weakdef.  Does it prevail?  If the
 552          owner is the original dummy bfd that supplied it, then this
 553          is the definition that has prevailed.  */
 554       if (owner_sec->owner == link_info.output_bfd)
 555         syms[n].resolution = LDPR_PREEMPTED_REG;
 556       else if (owner_sec->owner == abfd)
 557         {
 558           syms[n].resolution = (ironly
 559                                 ? LDPR_PREVAILING_DEF_IRONLY
 560                                 : LDPR_PREVAILING_DEF);
 561           goto report_symbol;
 562         }
 563
 564       /* Was originally def, weakdef, or common, but has been pre-empted.  */
 565       syms[n].resolution = (is_ir_dummy_bfd (owner_sec->owner)
 566                             ? LDPR_PREEMPTED_IR
 567                             : LDPR_PREEMPTED_REG);
 568
 569     report_symbol:
 570       if (report_plugin_symbols)
 571         einfo (_("%P: %B: symbol `%s' "
 572                  "definition: %d, visibility: %d, resolution: %d\n"),
 573                abfd, syms[n].name,
 574                syms[n].def, syms[n].visibility, syms[n].resolution);
 575     }
 576   return LDPS_OK;
 577 }
 578
 579 /* Add a new (real) input file generated by a plugin.  */
 580 static enum ld_plugin_status
 581 add_input_file (const char *pathname)
 582 {
 583   ASSERT (called_plugin);
 584   if (!lang_add_input_file (xstrdup (pathname), lang_input_file_is_file_enum,
 585                             NULL))
 586     return LDPS_ERR;
 587   return LDPS_OK;
 588 }
 589
 590 /* Add a new (real) library required by a plugin.  */
 591 static enum ld_plugin_status
 592 add_input_library (const char *pathname)
 593 {
 594   ASSERT (called_plugin);
 595   if (!lang_add_input_file (xstrdup (pathname), lang_input_file_is_l_enum,
 596                             NULL))
 597     return LDPS_ERR;
 598   return LDPS_OK;
 599 }
 600
 601 /* Set the extra library path to be used by libraries added via
 602    add_input_library.  */
 603 static enum ld_plugin_status
 604 set_extra_library_path (const char *path)
 605 {
 606   ASSERT (called_plugin);
 607   ldfile_add_library_path (xstrdup (path), FALSE);
 608   return LDPS_OK;
 609 }
 610
 611 /* Issue a diagnostic message from a plugin.  */
 612 static enum ld_plugin_status
 613 message (int level, const char *format, ...)
 614 {
 615   va_list args;
 616   va_start (args, format);
 617
 618   switch (level)
 619     {
 620     case LDPL_INFO:
 621       vfinfo (stdout, format, args, FALSE);
 622       putchar ('\n');
 623       break;
 624     case LDPL_WARNING:
 625       vfinfo (stdout, format, args, TRUE);
 626       putchar ('\n');
 627       break;
 628     case LDPL_FATAL:
 629     case LDPL_ERROR:
 630     default:
 631       {
 632         char *newfmt = ACONCAT ((level == LDPL_FATAL ? "%P%F: " : "%P%X: ",
 633                                  format, "\n", (const char *) NULL));
 634         fflush (stdout);
 635         vfinfo (stderr, newfmt, args, TRUE);
 636         fflush (stderr);
 637       }
 638       break;
 639     }
 640
 641   va_end (args);
 642   return LDPS_OK;
 643 }
 644
 645 /* Helper to size leading part of tv array and set it up. */
 646 static size_t
 647 set_tv_header (struct ld_plugin_tv *tv)
 648 {
 649   size_t i;
 650
 651   /* Version info.  */
 652   static const unsigned int major = (unsigned)(BFD_VERSION / 100000000UL);
 653   static const unsigned int minor = (unsigned)(BFD_VERSION / 1000000UL) % 100;
 654
 655   if (!tv)
 656     return tv_header_size;
 657
 658   for (i = 0; i < tv_header_size; i++)
 659     {
 660       tv[i].tv_tag = tv_header_tags[i];
 661 #define TVU(x) tv[i].tv_u.tv_ ## x
 662       switch (tv[i].tv_tag)
 663         {
 664         case LDPT_MESSAGE:
 665           TVU(message) = message;
 666           break;
 667         case LDPT_API_VERSION:
 668           TVU(val) = LD_PLUGIN_API_VERSION;
 669           break;
 670         case LDPT_GNU_LD_VERSION:
 671           TVU(val) = major * 100 + minor;
 672           break;
 673         case LDPT_LINKER_OUTPUT:
 674           TVU(val) = (link_info.relocatable
 675                       ? LDPO_REL
 676                       : (link_info.shared ? LDPO_DYN : LDPO_EXEC));
 677           break;
 678         case LDPT_OUTPUT_NAME:
 679           TVU(string) = output_filename;
 680           break;
 681         case LDPT_REGISTER_CLAIM_FILE_HOOK:
 682           TVU(register_claim_file) = register_claim_file;
 683           break;
 684         case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK:
 685           TVU(register_all_symbols_read) = register_all_symbols_read;
 686           break;
 687         case LDPT_REGISTER_CLEANUP_HOOK:
 688           TVU(register_cleanup) = register_cleanup;
 689           break;
 690         case LDPT_ADD_SYMBOLS:
 691           TVU(add_symbols) = add_symbols;
 692           break;
 693         case LDPT_GET_INPUT_FILE:
 694           TVU(get_input_file) = get_input_file;
 695           break;
 696         case LDPT_RELEASE_INPUT_FILE:
 697           TVU(release_input_file) = release_input_file;
 698           break;
 699         case LDPT_GET_SYMBOLS:
 700           TVU(get_symbols) = get_symbols;
 701           break;
 702         case LDPT_ADD_INPUT_FILE:
 703           TVU(add_input_file) = add_input_file;
 704           break;
 705         case LDPT_ADD_INPUT_LIBRARY:
 706           TVU(add_input_library) = add_input_library;
 707           break;
 708         case LDPT_SET_EXTRA_LIBRARY_PATH:
 709           TVU(set_extra_library_path) = set_extra_library_path;
 710           break;
 711         default:
 712           /* Added a new entry to the array without adding
 713              a new case to set up its value is a bug.  */
 714           FAIL ();
 715         }
 716 #undef TVU
 717     }
 718   return tv_header_size;
 719 }
 720
 721 /* Append the per-plugin args list and trailing LDPT_NULL to tv.  */
 722 static void
 723 set_tv_plugin_args (plugin_t *plugin, struct ld_plugin_tv *tv)
 724 {
 725   plugin_arg_t *arg = plugin->args;
 726   while (arg)
 727     {
 728       tv->tv_tag = LDPT_OPTION;
 729       tv->tv_u.tv_string = arg->arg;
 730       arg = arg->next;
 731       tv++;
 732     }
 733   tv->tv_tag = LDPT_NULL;
 734   tv->tv_u.tv_val = 0;
 735 }
 736
 737 /* Return true if any plugins are active this run.  Only valid
 738    after options have been processed.  */
 739 bfd_boolean
 740 plugin_active_plugins_p (void)
 741 {
 742   return plugins_list != NULL;
 743 }
 744
 745 /* Load up and initialise all plugins after argument parsing.  */
 746 int
 747 plugin_load_plugins (void)
 748 {
 749   struct ld_plugin_tv *my_tv;
 750   unsigned int max_args = 0;
 751   plugin_t *curplug = plugins_list;
 752
 753   /* If there are no plugins, we need do nothing this run.  */
 754   if (!curplug)
 755     return 0;
 756
 757   /* First pass over plugins to find max # args needed so that we
 758      can size and allocate the tv array.  */
 759   while (curplug)
 760     {
 761       if (curplug->n_args > max_args)
 762         max_args = curplug->n_args;
 763       curplug = curplug->next;
 764     }
 765
 766   /* Allocate tv array and initialise constant part.  */
 767   my_tv = xmalloc ((max_args + 1 + tv_header_size) * sizeof *my_tv);
 768   set_tv_header (my_tv);
 769
 770   /* Pass over plugins again, activating them.  */
 771   curplug = plugins_list;
 772   while (curplug)
 773     {
 774       enum ld_plugin_status rv;
 775       ld_plugin_onload onloadfn = dlsym (curplug->dlhandle, "onload");
 776       if (!onloadfn)
 777         onloadfn = dlsym (curplug->dlhandle, "_onload");
 778       if (!onloadfn)
 779         return set_plugin_error (curplug->name);
 780       set_tv_plugin_args (curplug, &my_tv[tv_header_size]);
 781       called_plugin = curplug;
 782       rv = (*onloadfn) (my_tv);
 783       called_plugin = NULL;
 784       if (rv != LDPS_OK)
 785         return set_plugin_error (curplug->name);
 786       curplug = curplug->next;
 787     }
 788
 789   /* Since plugin(s) inited ok, assume they're going to want symbol
 790      resolutions, which needs us to track which symbols are referenced
 791      by non-IR files using the linker's notice callback.  */
 792   orig_notice_all = link_info.notice_all;
 793   orig_callbacks = link_info.callbacks;
 794   plugin_callbacks = *orig_callbacks;
 795   plugin_callbacks.notice = &plugin_notice;
 796   link_info.notice_all = TRUE;
 797   link_info.callbacks = &plugin_callbacks;
 798
 799   return 0;
 800 }
 801
 802 /* Call 'claim file' hook for all plugins.  */
 803 static int
 804 plugin_call_claim_file (const struct ld_plugin_input_file *file, int *claimed)
 805 {
 806   plugin_t *curplug = plugins_list;
 807   *claimed = FALSE;
 808   if (no_more_claiming)
 809     return 0;
 810   while (curplug && !*claimed)
 811     {
 812       if (curplug->claim_file_handler)
 813         {
 814           enum ld_plugin_status rv;
 815           called_plugin = curplug;
 816           rv = (*curplug->claim_file_handler) (file, claimed);
 817           called_plugin = NULL;
 818           if (rv != LDPS_OK)
 819             set_plugin_error (curplug->name);
 820         }
 821       curplug = curplug->next;
 822     }
 823   return plugin_error_p () ? -1 : 0;
 824 }
 825
 826 void
 827 plugin_maybe_claim (struct ld_plugin_input_file *file,
 828                     lang_input_statement_type *entry)
 829 {
 830   int claimed = 0;
 831
 832   /* We create a dummy BFD, initially empty, to house whatever symbols
 833      the plugin may want to add.  */
 834   file->handle = plugin_get_ir_dummy_bfd (entry->the_bfd->filename,
 835                                           entry->the_bfd);
 836   if (plugin_call_claim_file (file, &claimed))
 837     einfo (_("%P%F: %s: plugin reported error claiming file\n"),
 838            plugin_error_plugin ());
 839   /* fd belongs to us, not the plugin; but we don't need it.  */
 840   close (file->fd);
 841   if (claimed)
 842     {
 843       /* Discard the real file's BFD and substitute the dummy one.  */
 844
 845       /* BFD archive handling caches elements so we can't call
 846          bfd_close for archives.  */
 847       if (entry->the_bfd->my_archive == NULL)
 848         bfd_close (entry->the_bfd);
 849       entry->the_bfd = file->handle;
 850       entry->claimed = TRUE;
 851       bfd_make_readable (entry->the_bfd);
 852     }
 853   else
 854     {
 855       /* If plugin didn't claim the file, we don't need the dummy bfd.
 856          Can't avoid speculatively creating it, alas.  */
 857       bfd_close_all_done (file->handle);
 858       entry->claimed = FALSE;
 859     }
 860 }
 861
 862 /* Call 'all symbols read' hook for all plugins.  */
 863 int
 864 plugin_call_all_symbols_read (void)
 865 {
 866   plugin_t *curplug = plugins_list;
 867
 868   /* Disable any further file-claiming.  */
 869   no_more_claiming = TRUE;
 870
 871   while (curplug)
 872     {
 873       if (curplug->all_symbols_read_handler)
 874         {
 875           enum ld_plugin_status rv;
 876           called_plugin = curplug;
 877           rv = (*curplug->all_symbols_read_handler) ();
 878           called_plugin = NULL;
 879           if (rv != LDPS_OK)
 880             set_plugin_error (curplug->name);
 881         }
 882       curplug = curplug->next;
 883     }
 884   return plugin_error_p () ? -1 : 0;
 885 }
 886
 887 /* Call 'cleanup' hook for all plugins at exit.  */
 888 void
 889 plugin_call_cleanup (void)
 890 {
 891   plugin_t *curplug = plugins_list;
 892   while (curplug)
 893     {
 894       if (curplug->cleanup_handler && !curplug->cleanup_done)
 895         {
 896           enum ld_plugin_status rv;
 897           curplug->cleanup_done = TRUE;
 898           called_plugin = curplug;
 899           rv = (*curplug->cleanup_handler) ();
 900           called_plugin = NULL;
 901           if (rv != LDPS_OK)
 902             set_plugin_error (curplug->name);
 903           dlclose (curplug->dlhandle);
 904         }
 905       curplug = curplug->next;
 906     }
 907   if (plugin_error_p ())
 908     info_msg (_("%P: %s: error in plugin cleanup (ignored)\n"),
 909               plugin_error_plugin ());
 910 }
 911
 912 /* To determine which symbols should be resolved LDPR_PREVAILING_DEF
 913    and which LDPR_PREVAILING_DEF_IRONLY, we notice all the symbols as
 914    the linker adds them to the linker hash table.  Mark those
 915    referenced from a non-IR file with non_ir_ref.  We have to
 916    notice_all symbols, because we won't necessarily know until later
 917    which ones will be contributed by IR files.  */
 918 static bfd_boolean
 919 plugin_notice (struct bfd_link_info *info,
 920                struct bfd_link_hash_entry *h,
 921                bfd *abfd,
 922                asection *section,
 923                bfd_vma value,
 924                flagword flags,
 925                const char *string)
 926 {
 927   if (h != NULL)
 928     {
 929       bfd *sym_bfd;
 930
 931       /* No further processing if this def/ref is from an IR dummy BFD.  */
 932       if (is_ir_dummy_bfd (abfd))
 933         return TRUE;
 934
 935       /* Making an indirect symbol counts as a reference unless this
 936          is a brand new symbol.  */
 937       if (bfd_is_ind_section (section)
 938           || (flags & BSF_INDIRECT) != 0)
 939         {
 940           if (h->type != bfd_link_hash_new)
 941             {
 942               struct bfd_link_hash_entry *inh;
 943
 944               h->non_ir_ref = TRUE;
 945               inh = bfd_wrapped_link_hash_lookup (abfd, info, string, FALSE,
 946                                                   FALSE, FALSE);
 947               if (inh != NULL)
 948                 inh->non_ir_ref = TRUE;
 949             }
 950         }
 951
 952       /* Nothing to do here for warning symbols.  */
 953       else if ((flags & BSF_WARNING) != 0)
 954         ;
 955
 956       /* Nothing to do here for constructor symbols.  */
 957       else if ((flags & BSF_CONSTRUCTOR) != 0)
 958         ;
 959
 960       /* If this is a ref, set non_ir_ref.  */
 961       else if (bfd_is_und_section (section))
 962         h->non_ir_ref = TRUE;
 963
 964       /* Otherwise, it must be a new def.  Ensure any symbol defined
 965          in an IR dummy BFD takes on a new value from a real BFD.
 966          Weak symbols are not normally overridden by a new weak
 967          definition, and strong symbols will normally cause multiple
 968          definition errors.  Avoid this by making the symbol appear
 969          to be undefined.  */
 970       else if (((h->type == bfd_link_hash_defweak
 971                  || h->type == bfd_link_hash_defined)
 972                 && is_ir_dummy_bfd (sym_bfd = h->u.def.section->owner))
 973                || (h->type == bfd_link_hash_common
 974                    && is_ir_dummy_bfd (sym_bfd = h->u.c.p->section->owner)))
 975         {
 976           h->type = bfd_link_hash_undefweak;
 977           h->u.undef.abfd = sym_bfd;
 978         }
 979     }
 980
 981   /* Continue with cref/nocrossref/trace-sym processing.  */
 982   if (h == NULL
 983       || orig_notice_all
 984       || (info->notice_hash != NULL
 985           && bfd_hash_lookup (info->notice_hash, h->root.string,
 986                               FALSE, FALSE) != NULL))
 987     return (*orig_callbacks->notice) (info, h,
 988                                       abfd, section, value, flags, string);
 989   return TRUE;
 990 }