gold/plugin.cc

   1 // plugin.c -- plugin manager for gold      -*- C++ -*-
   2
   3 // Copyright 2008 Free Software Foundation, Inc.
   4 // Written by Cary Coutant <ccoutant@google.com>.
   5
   6 // This file is part of gold.
   7
   8 // This program is free software; you can redistribute it and/or modify
   9 // it under the terms of the GNU General Public License as published by
  10 // the Free Software Foundation; either version 3 of the License, or
  11 // (at your option) any later version.
  12
  13 // This program is distributed in the hope that it will be useful,
  14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 // GNU General Public License for more details.
  17
  18 // You should have received a copy of the GNU General Public License
  19 // along with this program; if not, write to the Free Software
  20 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  21 // MA 02110-1301, USA.
  22
  23 #include <cstdio>
  24 #include <cstdarg>
  25 #include <cstring>
  26 #include <string>
  27 #include <vector>
  28 #include <dlfcn.h>
  29
  30 #include "gold.h"
  31 #include "parameters.h"
  32 #include "errors.h"
  33 #include "fileread.h"
  34 #include "layout.h"
  35 #include "options.h"
  36 #include "plugin.h"
  37 #include "target.h"
  38 #include "readsyms.h"
  39 #include "symtab.h"
  40 #include "elfcpp.h"
  41
  42 namespace gold
  43 {
  44
  45 #ifdef ENABLE_PLUGINS
  46
  47 // The linker's exported interfaces.
  48
  49 extern "C"
  50 {
  51
  52 static enum ld_plugin_status
  53 register_claim_file(ld_plugin_claim_file_handler handler);
  54
  55 static enum ld_plugin_status
  56 register_all_symbols_read(ld_plugin_all_symbols_read_handler handler);
  57
  58 static enum ld_plugin_status
  59 register_cleanup(ld_plugin_cleanup_handler handler);
  60
  61 static enum ld_plugin_status
  62 add_symbols(void *handle, int nsyms, const struct ld_plugin_symbol *syms);
  63
  64 static enum ld_plugin_status
  65 get_symbols(const void *handle, int nsyms, struct ld_plugin_symbol *syms);
  66
  67 static enum ld_plugin_status
  68 add_input_file(char *pathname);
  69
  70 static enum ld_plugin_status
  71 message(int level, const char *format, ...);
  72
  73 };
  74
  75 #endif // ENABLE_PLUGINS
  76
  77 static Pluginobj* make_sized_plugin_object(Input_file* input_file,
  78                                            off_t offset);
  79
  80 // Plugin methods.
  81
  82 // Load one plugin library.
  83
  84 void
  85 Plugin::load()
  86 {
  87 #ifdef ENABLE_PLUGINS
  88   // Load the plugin library.
  89   // FIXME: Look for the library in standard locations.
  90   this->handle_ = dlopen(this->filename_.c_str(), RTLD_NOW);
  91   if (this->handle_ == NULL)
  92     {
  93       gold_error(_("%s: could not load plugin library"),
  94                  this->filename_.c_str());
  95       return;
  96     }
  97
  98   // Find the plugin's onload entry point.
  99   ld_plugin_onload onload = reinterpret_cast<ld_plugin_onload>
 100     (dlsym(this->handle_, "onload"));
 101   if (onload == NULL)
 102     {
 103       gold_error(_("%s: could not find onload entry point"),
 104                  this->filename_.c_str());
 105       return;
 106     }
 107
 108   // Get the linker's version number.
 109   const char* ver = get_version_string();
 110   int major = 0;
 111   int minor = 0;
 112   sscanf(ver, "%d.%d", &major, &minor);
 113
 114   // Allocate and populate a transfer vector.
 115   const int tv_fixed_size = 11;
 116   int tv_size = this->args_.size() + tv_fixed_size;
 117   ld_plugin_tv *tv = new ld_plugin_tv[tv_size];
 118
 119   // Put LDPT_MESSAGE at the front of the list so the plugin can use it
 120   // while processing subsequent entries.
 121   int i = 0;
 122   tv[i].tv_tag = LDPT_MESSAGE;
 123   tv[i].tv_u.tv_message = message;
 124
 125   ++i;
 126   tv[i].tv_tag = LDPT_API_VERSION;
 127   tv[i].tv_u.tv_val = LD_PLUGIN_API_VERSION;
 128
 129   ++i;
 130   tv[i].tv_tag = LDPT_GOLD_VERSION;
 131   tv[i].tv_u.tv_val = major * 100 + minor;
 132
 133   ++i;
 134   tv[i].tv_tag = LDPT_LINKER_OUTPUT;
 135   if (parameters->options().relocatable())
 136     tv[i].tv_u.tv_val = LDPO_REL;
 137   else if (parameters->options().shared())
 138     tv[i].tv_u.tv_val = LDPO_DYN;
 139   else
 140     tv[i].tv_u.tv_val = LDPO_EXEC;
 141
 142   for (unsigned int j = 0; j < this->args_.size(); ++j)
 143     {
 144       ++i;
 145       tv[i].tv_tag = LDPT_OPTION;
 146       tv[i].tv_u.tv_string = this->args_[j].c_str();
 147     }
 148
 149   ++i;
 150   tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
 151   tv[i].tv_u.tv_register_claim_file = register_claim_file;
 152
 153   ++i;
 154   tv[i].tv_tag = LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK;
 155   tv[i].tv_u.tv_register_all_symbols_read = register_all_symbols_read;
 156
 157   ++i;
 158   tv[i].tv_tag = LDPT_REGISTER_CLEANUP_HOOK;
 159   tv[i].tv_u.tv_register_cleanup = register_cleanup;
 160
 161   ++i;
 162   tv[i].tv_tag = LDPT_ADD_SYMBOLS;
 163   tv[i].tv_u.tv_add_symbols = add_symbols;
 164
 165   ++i;
 166   tv[i].tv_tag = LDPT_GET_SYMBOLS;
 167   tv[i].tv_u.tv_get_symbols = get_symbols;
 168
 169   ++i;
 170   tv[i].tv_tag = LDPT_ADD_INPUT_FILE;
 171   tv[i].tv_u.tv_add_input_file = add_input_file;
 172
 173   ++i;
 174   tv[i].tv_tag = LDPT_NULL;
 175   tv[i].tv_u.tv_val = 0;
 176
 177   gold_assert(i == tv_size - 1);
 178
 179   // Call the onload entry point.
 180   (*onload)(tv);
 181
 182   delete[] tv;
 183 #endif // ENABLE_PLUGINS
 184 }
 185
 186 // Call the plugin claim-file handler.
 187
 188 inline bool
 189 Plugin::claim_file(struct ld_plugin_input_file *plugin_input_file)
 190 {
 191   int claimed = 0;
 192
 193   if (this->claim_file_handler_ != NULL)
 194     {
 195       (*this->claim_file_handler_)(plugin_input_file, &claimed);
 196       if (claimed)
 197         return true;
 198     }
 199   return false;
 200 }
 201
 202 // Call the all-symbols-read handler.
 203
 204 inline void
 205 Plugin::all_symbols_read()
 206 {
 207   if (this->all_symbols_read_handler_ != NULL)
 208     (*this->all_symbols_read_handler_)();
 209 }
 210
 211 // Call the cleanup handler.
 212
 213 inline void
 214 Plugin::cleanup()
 215 {
 216   if (this->cleanup_handler_ != NULL)
 217     (*this->cleanup_handler_)();
 218 }
 219
 220 // Plugin_manager methods.
 221
 222 Plugin_manager::~Plugin_manager()
 223 {
 224   for (Plugin_list::iterator p = this->plugins_.begin();
 225        p != this->plugins_.end();
 226        ++p)
 227     delete *p;
 228   this->plugins_.clear();
 229   for (Object_list::iterator obj = this->objects_.begin();
 230        obj != this->objects_.end();
 231        ++obj)
 232     delete *obj;
 233   this->objects_.clear();
 234 }
 235
 236 // Load all plugin libraries.
 237
 238 void
 239 Plugin_manager::load_plugins()
 240 {
 241   for (this->current_ = this->plugins_.begin();
 242        this->current_ != this->plugins_.end();
 243        ++this->current_)
 244     (*this->current_)->load();
 245 }
 246
 247 // Call the plugin claim-file handlers in turn to see if any claim the file.
 248
 249 Pluginobj*
 250 Plugin_manager::claim_file(Input_file* input_file, off_t offset,
 251                            off_t filesize)
 252 {
 253   if (this->in_replacement_phase_)
 254     return NULL;
 255
 256   unsigned int handle = this->objects_.size();
 257   this->input_file_ = input_file;
 258   this->plugin_input_file_.name = input_file->filename().c_str();
 259   this->plugin_input_file_.fd = input_file->file().descriptor();
 260   this->plugin_input_file_.offset = offset;
 261   this->plugin_input_file_.filesize = filesize;
 262   this->plugin_input_file_.handle = reinterpret_cast<void*>(handle);
 263
 264   for (this->current_ = this->plugins_.begin();
 265        this->current_ != this->plugins_.end();
 266        ++this->current_)
 267     {
 268       if ((*this->current_)->claim_file(&this->plugin_input_file_))
 269         {
 270           if (this->objects_.size() > handle)
 271             return this->objects_[handle];
 272
 273           // If the plugin claimed the file but did not call the
 274           // add_symbols callback, we need to create the Pluginobj now.
 275           Pluginobj* obj = this->make_plugin_object(handle);
 276           return obj;
 277         }
 278     }
 279
 280   return NULL;
 281 }
 282
 283 // Call the all-symbols-read handlers.
 284
 285 void
 286 Plugin_manager::all_symbols_read(Workqueue* workqueue,
 287                                  Input_objects* input_objects,
 288                                  Symbol_table* symtab, Layout* layout,
 289                                  Dirsearch* dirpath, Mapfile* mapfile,
 290                                  Task_token** last_blocker)
 291 {
 292   this->in_replacement_phase_ = true;
 293   this->workqueue_ = workqueue;
 294   this->input_objects_ = input_objects;
 295   this->symtab_ = symtab;
 296   this->layout_ = layout;
 297   this->dirpath_ = dirpath;
 298   this->mapfile_ = mapfile;
 299   this->this_blocker_ = NULL;
 300
 301   for (this->current_ = this->plugins_.begin();
 302        this->current_ != this->plugins_.end();
 303        ++this->current_)
 304     (*this->current_)->all_symbols_read();
 305
 306   *last_blocker = this->this_blocker_;
 307 }
 308
 309 // Layout deferred sections and call the cleanup handlers.
 310
 311 void
 312 Plugin_manager::finish()
 313 {
 314   Deferred_layout_list::iterator obj;
 315
 316   for (obj = this->deferred_layout_objects_.begin();
 317        obj != this->deferred_layout_objects_.end();
 318        ++obj)
 319     (*obj)->layout_deferred_sections(this->layout_);
 320
 321   for (this->current_ = this->plugins_.begin();
 322        this->current_ != this->plugins_.end();
 323        ++this->current_)
 324     (*this->current_)->cleanup();
 325 }
 326
 327 // Make a new Pluginobj object.  This is called when the plugin calls
 328 // the add_symbols API.
 329
 330 Pluginobj*
 331 Plugin_manager::make_plugin_object(unsigned int handle)
 332 {
 333   // Make sure we aren't asked to make an object for the same handle twice.
 334   if (this->objects_.size() != handle)
 335     return NULL;
 336
 337   Pluginobj* obj = make_sized_plugin_object(this->input_file_,
 338                                             this->plugin_input_file_.offset);
 339   this->objects_.push_back(obj);
 340   return obj;
 341 }
 342
 343 // Add a new input file.
 344
 345 ld_plugin_status
 346 Plugin_manager::add_input_file(char *pathname)
 347 {
 348   Input_file_argument file(pathname, false, "", false, this->options_);
 349   Input_argument* input_argument = new Input_argument(file);
 350   Task_token* next_blocker = new Task_token(true);
 351   next_blocker->add_blocker();
 352   this->workqueue_->queue_soon(new Read_symbols(this->options_,
 353                                                 this->input_objects_,
 354                                                 this->symtab_,
 355                                                 this->layout_,
 356                                                 this->dirpath_,
 357                                                 this->mapfile_,
 358                                                 input_argument,
 359                                                 NULL,
 360                                                 this->this_blocker_,
 361                                                 next_blocker));
 362   this->this_blocker_ = next_blocker;
 363   return LDPS_OK;
 364 }
 365
 366 // Class Pluginobj.
 367
 368 Pluginobj::Pluginobj(const std::string& name, Input_file* input_file,
 369                      off_t offset)
 370   : Object(name, input_file, false, offset),
 371     nsyms_(0), syms_(NULL), symbols_(), comdat_map_()
 372 {
 373 }
 374
 375 // Get symbol resolution info.
 376
 377 ld_plugin_status
 378 Pluginobj::get_symbol_resolution_info(int nsyms, ld_plugin_symbol* syms) const
 379 {
 380   if (nsyms > this->nsyms_)
 381     return LDPS_NO_SYMS;
 382   for (int i = 0; i < nsyms; i++)
 383     {
 384       ld_plugin_symbol* isym = &syms[i];
 385       Symbol* lsym = this->symbols_[i];
 386       ld_plugin_symbol_resolution res = LDPR_UNKNOWN;
 387
 388       if (lsym->is_undefined())
 389         // The symbol remains undefined.
 390         res = LDPR_UNDEF;
 391       else if (isym->def == LDPK_UNDEF
 392                || isym->def == LDPK_WEAKUNDEF
 393                || isym->def == LDPK_COMMON)
 394         {
 395           // The original symbol was undefined or common.
 396           if (lsym->source() != Symbol::FROM_OBJECT)
 397             res = LDPR_RESOLVED_EXEC;
 398           else if (lsym->object()->pluginobj() != NULL)
 399             res = LDPR_RESOLVED_IR;
 400           else if (lsym->object()->is_dynamic())
 401             res = LDPR_RESOLVED_DYN;
 402           else
 403             res = LDPR_RESOLVED_EXEC;
 404         }
 405       else
 406         {
 407           // The original symbol was a definition.
 408           if (lsym->source() != Symbol::FROM_OBJECT)
 409             res = LDPR_PREEMPTED_REG;
 410           else if (lsym->object() == static_cast<const Object*>(this))
 411             res = (lsym->in_real_elf()
 412                    ? LDPR_PREVAILING_DEF
 413                    : LDPR_PREVAILING_DEF_IRONLY);
 414           else
 415             res = (lsym->object()->pluginobj() != NULL
 416                    ? LDPR_PREEMPTED_IR
 417                    : LDPR_PREEMPTED_REG);
 418         }
 419       isym->resolution = res;
 420     }
 421   return LDPS_OK;
 422 }
 423
 424 // Return TRUE if the comdat group with key COMDAT_KEY from this object
 425 // should be kept.
 426
 427 bool
 428 Pluginobj::include_comdat_group(std::string comdat_key, Layout* layout)
 429 {
 430   std::pair<Comdat_map::iterator, bool> ins =
 431     this->comdat_map_.insert(std::make_pair(comdat_key, false));
 432
 433   // If this is the first time we've seen this comdat key, ask the
 434   // layout object whether it should be included.
 435   if (ins.second)
 436     ins.first->second = layout->add_comdat(NULL, 1, comdat_key, true);
 437
 438   return ins.first->second;
 439 }
 440
 441 // Class Sized_pluginobj.
 442
 443 template<int size, bool big_endian>
 444 Sized_pluginobj<size, big_endian>::Sized_pluginobj(
 445     const std::string& name,
 446     Input_file* input_file,
 447     off_t offset)
 448   : Pluginobj(name, input_file, offset)
 449 {
 450 }
 451
 452 // Read the symbols.  Not used for plugin objects.
 453
 454 template<int size, bool big_endian>
 455 void
 456 Sized_pluginobj<size, big_endian>::do_read_symbols(Read_symbols_data*)
 457 {
 458   gold_unreachable();
 459 }
 460
 461 // Lay out the input sections.  Not used for plugin objects.
 462
 463 template<int size, bool big_endian>
 464 void
 465 Sized_pluginobj<size, big_endian>::do_layout(Symbol_table*, Layout*,
 466                                              Read_symbols_data*)
 467 {
 468   gold_unreachable();
 469 }
 470
 471 // Add the symbols to the symbol table.
 472
 473 template<int size, bool big_endian>
 474 void
 475 Sized_pluginobj<size, big_endian>::do_add_symbols(Symbol_table*,
 476                                                   Read_symbols_data*)
 477 {
 478   gold_unreachable();
 479 }
 480
 481 template<int size, bool big_endian>
 482 void
 483 Sized_pluginobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
 484                                                   Layout* layout)
 485 {
 486   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
 487   unsigned char symbuf[sym_size];
 488   elfcpp::Sym<size, big_endian> sym(symbuf);
 489   elfcpp::Sym_write<size, big_endian> osym(symbuf);
 490
 491   typedef typename elfcpp::Elf_types<size>::Elf_WXword Elf_size_type;
 492
 493   this->symbols_.resize(this->nsyms_);
 494
 495   for (int i = 0; i < this->nsyms_; ++i)
 496     {
 497       const struct ld_plugin_symbol *isym = &this->syms_[i];
 498       const char* name = isym->name;
 499       const char* ver = isym->version;
 500       elfcpp::Elf_Half shndx;
 501       elfcpp::STB bind;
 502       elfcpp::STV vis;
 503
 504       if (name != NULL && name[0] == '\0')
 505         name = NULL;
 506       if (ver != NULL && ver[0] == '\0')
 507         ver = NULL;
 508
 509       switch (isym->def)
 510         {
 511         case LDPK_WEAKDEF:
 512         case LDPK_WEAKUNDEF:
 513           bind = elfcpp::STB_WEAK;
 514           break;
 515         case LDPK_DEF:
 516         case LDPK_UNDEF:
 517         case LDPK_COMMON:
 518         default:
 519           bind = elfcpp::STB_GLOBAL;
 520           break;
 521         }
 522
 523       switch (isym->def)
 524         {
 525         case LDPK_DEF:
 526         case LDPK_WEAKDEF:
 527           shndx = elfcpp::SHN_ABS;
 528           break;
 529         case LDPK_COMMON:
 530           shndx = elfcpp::SHN_COMMON;
 531           break;
 532         case LDPK_UNDEF:
 533         case LDPK_WEAKUNDEF:
 534         default:
 535           shndx = elfcpp::SHN_UNDEF;
 536           break;
 537         }
 538
 539       switch (isym->visibility)
 540         {
 541         case LDPV_PROTECTED:
 542           vis = elfcpp::STV_DEFAULT;
 543           break;
 544         case LDPV_INTERNAL:
 545           vis = elfcpp::STV_DEFAULT;
 546           break;
 547         case LDPV_HIDDEN:
 548           vis = elfcpp::STV_DEFAULT;
 549           break;
 550         case LDPV_DEFAULT:
 551         default:
 552           vis = elfcpp::STV_DEFAULT;
 553           break;
 554         }
 555
 556       if (isym->comdat_key != NULL
 557           && isym->comdat_key[0] != '\0'
 558           && !this->include_comdat_group(isym->comdat_key, layout))
 559         shndx = elfcpp::SHN_UNDEF;
 560
 561       osym.put_st_name(0);
 562       osym.put_st_value(0);
 563       osym.put_st_size(static_cast<Elf_size_type>(isym->size));
 564       osym.put_st_info(bind, elfcpp::STT_NOTYPE);
 565       osym.put_st_other(vis, 0);
 566       osym.put_st_shndx(shndx);
 567
 568       this->symbols_[i] =
 569         symtab->add_from_pluginobj<size, big_endian>(this, name, ver, &sym);
 570     }
 571 }
 572
 573 // Get the size of a section.  Not used for plugin objects.
 574
 575 template<int size, bool big_endian>
 576 uint64_t
 577 Sized_pluginobj<size, big_endian>::do_section_size(unsigned int)
 578 {
 579   gold_unreachable();
 580   return 0;
 581 }
 582
 583 // Get the name of a section.  Not used for plugin objects.
 584
 585 template<int size, bool big_endian>
 586 std::string
 587 Sized_pluginobj<size, big_endian>::do_section_name(unsigned int)
 588 {
 589   gold_unreachable();
 590   return std::string();
 591 }
 592
 593 // Return a view of the contents of a section.  Not used for plugin objects.
 594
 595 template<int size, bool big_endian>
 596 Object::Location
 597 Sized_pluginobj<size, big_endian>::do_section_contents(unsigned int)
 598 {
 599   Location loc(0, 0);
 600
 601   gold_unreachable();
 602   return loc;
 603 }
 604
 605 // Return section flags.  Not used for plugin objects.
 606
 607 template<int size, bool big_endian>
 608 uint64_t
 609 Sized_pluginobj<size, big_endian>::do_section_flags(unsigned int)
 610 {
 611   gold_unreachable();
 612   return 0;
 613 }
 614
 615 // Return section address.  Not used for plugin objects.
 616
 617 template<int size, bool big_endian>
 618 uint64_t
 619 Sized_pluginobj<size, big_endian>::do_section_address(unsigned int)
 620 {
 621   gold_unreachable();
 622   return 0;
 623 }
 624
 625 // Return section type.  Not used for plugin objects.
 626
 627 template<int size, bool big_endian>
 628 unsigned int
 629 Sized_pluginobj<size, big_endian>::do_section_type(unsigned int)
 630 {
 631   gold_unreachable();
 632   return 0;
 633 }
 634
 635 // Return the section link field.  Not used for plugin objects.
 636
 637 template<int size, bool big_endian>
 638 unsigned int
 639 Sized_pluginobj<size, big_endian>::do_section_link(unsigned int)
 640 {
 641   gold_unreachable();
 642   return 0;
 643 }
 644
 645 // Return the section link field.  Not used for plugin objects.
 646
 647 template<int size, bool big_endian>
 648 unsigned int
 649 Sized_pluginobj<size, big_endian>::do_section_info(unsigned int)
 650 {
 651   gold_unreachable();
 652   return 0;
 653 }
 654
 655 // Return the section alignment.  Not used for plugin objects.
 656
 657 template<int size, bool big_endian>
 658 uint64_t
 659 Sized_pluginobj<size, big_endian>::do_section_addralign(unsigned int)
 660 {
 661   gold_unreachable();
 662   return 0;
 663 }
 664
 665 // Return the Xindex structure to use.  Not used for plugin objects.
 666
 667 template<int size, bool big_endian>
 668 Xindex*
 669 Sized_pluginobj<size, big_endian>::do_initialize_xindex()
 670 {
 671   gold_unreachable();
 672   return NULL;
 673 }
 674
 675 // Get symbol counts.  Not used for plugin objects.
 676
 677 template<int size, bool big_endian>
 678 void
 679 Sized_pluginobj<size, big_endian>::do_get_global_symbol_counts(const Symbol_table*,
 680                                                    size_t*, size_t*) const
 681 {
 682   gold_unreachable();
 683 }
 684
 685 // Class Add_plugin_symbols.
 686
 687 Add_plugin_symbols::~Add_plugin_symbols()
 688 {
 689   if (this->this_blocker_ != NULL)
 690     delete this->this_blocker_;
 691   // next_blocker_ is deleted by the task associated with the next
 692   // input file.
 693 }
 694
 695 // We are blocked by this_blocker_.  We block next_blocker_.  We also
 696 // lock the file.
 697
 698 Task_token*
 699 Add_plugin_symbols::is_runnable()
 700 {
 701   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
 702     return this->this_blocker_;
 703   if (this->obj_->is_locked())
 704     return this->obj_->token();
 705   return NULL;
 706 }
 707
 708 void
 709 Add_plugin_symbols::locks(Task_locker* tl)
 710 {
 711   tl->add(this, this->next_blocker_);
 712   tl->add(this, this->obj_->token());
 713 }
 714
 715 // Add the symbols in the object to the symbol table.
 716
 717 void
 718 Add_plugin_symbols::run(Workqueue*)
 719 {
 720   this->obj_->add_symbols(this->symtab_, this->layout_);
 721 }
 722
 723 // Class Plugin_finish.  This task runs after all replacement files have
 724 // been added.  It calls Layout::layout for any deferred sections and
 725 // calls each plugin's cleanup handler.
 726
 727 class Plugin_finish : public Task
 728 {
 729  public:
 730   Plugin_finish(Task_token* this_blocker, Task_token* next_blocker)
 731     : this_blocker_(this_blocker), next_blocker_(next_blocker)
 732   { }
 733
 734   ~Plugin_finish()
 735   {
 736     if (this->this_blocker_ != NULL)
 737       delete this->this_blocker_;
 738   }
 739
 740   Task_token*
 741   is_runnable()
 742   {
 743     if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
 744       return this->this_blocker_;
 745     return NULL;
 746   }
 747
 748   void
 749   locks(Task_locker* tl)
 750   { tl->add(this, this->next_blocker_); }
 751
 752   void
 753   run(Workqueue*)
 754   { parameters->options().plugins()->finish(); }
 755
 756   std::string
 757   get_name() const
 758   { return "Plugin_finish"; }
 759
 760  private:
 761   Task_token* this_blocker_;
 762   Task_token* next_blocker_;
 763 };
 764
 765 // Class Plugin_hook.
 766
 767 Plugin_hook::~Plugin_hook()
 768 {
 769 }
 770
 771 // Return whether a Plugin_hook task is runnable.
 772
 773 Task_token*
 774 Plugin_hook::is_runnable()
 775 {
 776   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
 777     return this->this_blocker_;
 778   return NULL;
 779 }
 780
 781 // Return a Task_locker for a Plugin_hook task.  We don't need any
 782 // locks here.
 783
 784 void
 785 Plugin_hook::locks(Task_locker*)
 786 {
 787 }
 788
 789 // Run the "all symbols read" plugin hook.
 790
 791 void
 792 Plugin_hook::run(Workqueue* workqueue)
 793 {
 794   gold_assert(this->options_.has_plugins());
 795   this->options_.plugins()->all_symbols_read(workqueue,
 796                                              this->input_objects_,
 797                                              this->symtab_,
 798                                              this->layout_,
 799                                              this->dirpath_,
 800                                              this->mapfile_,
 801                                              &this->this_blocker_);
 802   workqueue->queue_soon(new Plugin_finish(this->this_blocker_,
 803                                           this->next_blocker_));
 804 }
 805
 806 // The C interface routines called by the plugins.
 807
 808 #ifdef ENABLE_PLUGINS
 809
 810 // Register a claim-file handler.
 811
 812 static enum ld_plugin_status
 813 register_claim_file(ld_plugin_claim_file_handler handler)
 814 {
 815   gold_assert(parameters->options().has_plugins());
 816   parameters->options().plugins()->set_claim_file_handler(handler);
 817   return LDPS_OK;
 818 }
 819
 820 // Register an all-symbols-read handler.
 821
 822 static enum ld_plugin_status
 823 register_all_symbols_read(ld_plugin_all_symbols_read_handler handler)
 824 {
 825   gold_assert(parameters->options().has_plugins());
 826   parameters->options().plugins()->set_all_symbols_read_handler(handler);
 827   return LDPS_OK;
 828 }
 829
 830 // Register a cleanup handler.
 831
 832 static enum ld_plugin_status
 833 register_cleanup(ld_plugin_cleanup_handler handler)
 834 {
 835   gold_assert(parameters->options().has_plugins());
 836   parameters->options().plugins()->set_cleanup_handler(handler);
 837   return LDPS_OK;
 838 }
 839
 840 // Add symbols from a plugin-claimed input file.
 841
 842 static enum ld_plugin_status
 843 add_symbols(void* handle, int nsyms, const ld_plugin_symbol *syms)
 844 {
 845   gold_assert(parameters->options().has_plugins());
 846   Pluginobj* obj = parameters->options().plugins()->make_plugin_object(
 847       static_cast<unsigned int>(reinterpret_cast<intptr_t>(handle)));
 848   if (obj == NULL)
 849     return LDPS_ERR;
 850   obj->store_incoming_symbols(nsyms, syms);
 851   return LDPS_OK;
 852 }
 853
 854 // Get the symbol resolution info for a plugin-claimed input file.
 855
 856 static enum ld_plugin_status
 857 get_symbols(const void * handle, int nsyms, ld_plugin_symbol* syms)
 858 {
 859   gold_assert(parameters->options().has_plugins());
 860   Pluginobj* obj = parameters->options().plugins()->object(
 861       static_cast<unsigned int>(reinterpret_cast<intptr_t>(handle)));
 862   if (obj == NULL)
 863     return LDPS_ERR;
 864   return obj->get_symbol_resolution_info(nsyms, syms);
 865 }
 866
 867 // Add a new (real) input file generated by a plugin.
 868
 869 static enum ld_plugin_status
 870 add_input_file(char *pathname)
 871 {
 872   gold_assert(parameters->options().has_plugins());
 873   return parameters->options().plugins()->add_input_file(pathname);
 874 }
 875
 876 // Issue a diagnostic message from a plugin.
 877
 878 static enum ld_plugin_status
 879 message(int level, const char * format, ...)
 880 {
 881   va_list args;
 882   va_start(args, format);
 883
 884   switch (level)
 885     {
 886     case LDPL_INFO:
 887       parameters->errors()->info(format, args);
 888       break;
 889     case LDPL_WARNING:
 890       parameters->errors()->warning(format, args);
 891       break;
 892     case LDPL_ERROR:
 893     default:
 894       parameters->errors()->error(format, args);
 895       break;
 896     case LDPL_FATAL:
 897       parameters->errors()->fatal(format, args);
 898       break;
 899     }
 900
 901   va_end(args);
 902   return LDPS_OK;
 903 }
 904
 905 #endif // ENABLE_PLUGINS
 906
 907 // Allocate a Pluginobj object of the appropriate size and endianness.
 908
 909 static Pluginobj*
 910 make_sized_plugin_object(Input_file* input_file, off_t offset)
 911 {
 912   Target* target;
 913   Pluginobj* obj = NULL;
 914
 915   if (parameters->target_valid())
 916     target = const_cast<Target*>(&parameters->target());
 917   else
 918     target = const_cast<Target*>(&parameters->default_target());
 919
 920   if (target->get_size() == 32)
 921     {
 922       if (target->is_big_endian())
 923 #ifdef HAVE_TARGET_32_BIG
 924         obj = new Sized_pluginobj<32, true>(input_file->filename(),
 925                                             input_file, offset);
 926 #else
 927         gold_error(_("%s: not configured to support "
 928                      "32-bit big-endian object"),
 929                    input_file->filename().c_str());
 930 #endif
 931       else
 932 #ifdef HAVE_TARGET_32_LITTLE
 933         obj = new Sized_pluginobj<32, false>(input_file->filename(),
 934                                              input_file, offset);
 935 #else
 936         gold_error(_("%s: not configured to support "
 937                      "32-bit little-endian object"),
 938                    input_file->filename().c_str());
 939 #endif
 940     }
 941   else if (target->get_size() == 64)
 942     {
 943       if (target->is_big_endian())
 944 #ifdef HAVE_TARGET_64_BIG
 945         obj = new Sized_pluginobj<64, true>(input_file->filename(),
 946                                             input_file, offset);
 947 #else
 948         gold_error(_("%s: not configured to support "
 949                      "64-bit big-endian object"),
 950                    input_file->filename().c_str());
 951 #endif
 952       else
 953 #ifdef HAVE_TARGET_64_LITTLE
 954         obj = new Sized_pluginobj<64, false>(input_file->filename(),
 955                                              input_file, offset);
 956 #else
 957         gold_error(_("%s: not configured to support "
 958                      "64-bit little-endian object"),
 959                    input_file->filename().c_str());
 960 #endif
 961     }
 962
 963   gold_assert(obj != NULL);
 964   obj->set_target(target);
 965   return obj;
 966 }
 967
 968 } // End namespace gold.