gold/plugin.cc

   1 // plugin.cc -- plugin manager for gold      -*- C++ -*-
   2
   3 // Copyright 2008, 2009, 2010, 2011 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 "gold.h"
  24
  25 #include <cstdio>
  26 #include <cstdarg>
  27 #include <cstring>
  28 #include <string>
  29 #include <vector>
  30
  31 #ifdef ENABLE_PLUGINS
  32 #include <dlfcn.h>
  33 #endif
  34
  35 #include "parameters.h"
  36 #include "errors.h"
  37 #include "fileread.h"
  38 #include "layout.h"
  39 #include "options.h"
  40 #include "plugin.h"
  41 #include "target.h"
  42 #include "readsyms.h"
  43 #include "symtab.h"
  44 #include "elfcpp.h"
  45
  46 namespace gold
  47 {
  48
  49 #ifdef ENABLE_PLUGINS
  50
  51 // The linker's exported interfaces.
  52
  53 extern "C"
  54 {
  55
  56 static enum ld_plugin_status
  57 register_claim_file(ld_plugin_claim_file_handler handler);
  58
  59 static enum ld_plugin_status
  60 register_all_symbols_read(ld_plugin_all_symbols_read_handler handler);
  61
  62 static enum ld_plugin_status
  63 register_cleanup(ld_plugin_cleanup_handler handler);
  64
  65 static enum ld_plugin_status
  66 add_symbols(void *handle, int nsyms, const struct ld_plugin_symbol *syms);
  67
  68 static enum ld_plugin_status
  69 get_input_file(const void *handle, struct ld_plugin_input_file *file);
  70
  71 static enum ld_plugin_status
  72 get_view(const void *handle, const void **viewp);
  73
  74 static enum ld_plugin_status
  75 release_input_file(const void *handle);
  76
  77 static enum ld_plugin_status
  78 get_symbols(const void *handle, int nsyms, struct ld_plugin_symbol *syms);
  79
  80 static enum ld_plugin_status
  81 add_input_file(const char *pathname);
  82
  83 static enum ld_plugin_status
  84 add_input_library(const char *pathname);
  85
  86 static enum ld_plugin_status
  87 set_extra_library_path(const char *path);
  88
  89 static enum ld_plugin_status
  90 message(int level, const char *format, ...);
  91
  92 };
  93
  94 #endif // ENABLE_PLUGINS
  95
  96 static Pluginobj* make_sized_plugin_object(Input_file* input_file,
  97                                            off_t offset, off_t filesize);
  98
  99 // Plugin methods.
 100
 101 // Load one plugin library.
 102
 103 void
 104 Plugin::load()
 105 {
 106 #ifdef ENABLE_PLUGINS
 107   // Load the plugin library.
 108   // FIXME: Look for the library in standard locations.
 109   this->handle_ = dlopen(this->filename_.c_str(), RTLD_NOW);
 110   if (this->handle_ == NULL)
 111     {
 112       gold_error(_("%s: could not load plugin library: %s"),
 113                  this->filename_.c_str(), dlerror());
 114       return;
 115     }
 116
 117   // Find the plugin's onload entry point.
 118   void* ptr = dlsym(this->handle_, "onload");
 119   if (ptr == NULL)
 120     {
 121       gold_error(_("%s: could not find onload entry point"),
 122                  this->filename_.c_str());
 123       return;
 124     }
 125   ld_plugin_onload onload;
 126   gold_assert(sizeof(onload) == sizeof(ptr));
 127   memcpy(&onload, &ptr, sizeof(ptr));
 128
 129   // Get the linker's version number.
 130   const char* ver = get_version_string();
 131   int major = 0;
 132   int minor = 0;
 133   sscanf(ver, "%d.%d", &major, &minor);
 134
 135   // Allocate and populate a transfer vector.
 136   const int tv_fixed_size = 17;
 137   int tv_size = this->args_.size() + tv_fixed_size;
 138   ld_plugin_tv* tv = new ld_plugin_tv[tv_size];
 139
 140   // Put LDPT_MESSAGE at the front of the list so the plugin can use it
 141   // while processing subsequent entries.
 142   int i = 0;
 143   tv[i].tv_tag = LDPT_MESSAGE;
 144   tv[i].tv_u.tv_message = message;
 145
 146   ++i;
 147   tv[i].tv_tag = LDPT_API_VERSION;
 148   tv[i].tv_u.tv_val = LD_PLUGIN_API_VERSION;
 149
 150   ++i;
 151   tv[i].tv_tag = LDPT_GOLD_VERSION;
 152   tv[i].tv_u.tv_val = major * 100 + minor;
 153
 154   ++i;
 155   tv[i].tv_tag = LDPT_LINKER_OUTPUT;
 156   if (parameters->options().relocatable())
 157     tv[i].tv_u.tv_val = LDPO_REL;
 158   else if (parameters->options().shared())
 159     tv[i].tv_u.tv_val = LDPO_DYN;
 160   else
 161     tv[i].tv_u.tv_val = LDPO_EXEC;
 162
 163   ++i;
 164   tv[i].tv_tag = LDPT_OUTPUT_NAME;
 165   tv[i].tv_u.tv_string = parameters->options().output();
 166
 167   for (unsigned int j = 0; j < this->args_.size(); ++j)
 168     {
 169       ++i;
 170       tv[i].tv_tag = LDPT_OPTION;
 171       tv[i].tv_u.tv_string = this->args_[j].c_str();
 172     }
 173
 174   ++i;
 175   tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
 176   tv[i].tv_u.tv_register_claim_file = register_claim_file;
 177
 178   ++i;
 179   tv[i].tv_tag = LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK;
 180   tv[i].tv_u.tv_register_all_symbols_read = register_all_symbols_read;
 181
 182   ++i;
 183   tv[i].tv_tag = LDPT_REGISTER_CLEANUP_HOOK;
 184   tv[i].tv_u.tv_register_cleanup = register_cleanup;
 185
 186   ++i;
 187   tv[i].tv_tag = LDPT_ADD_SYMBOLS;
 188   tv[i].tv_u.tv_add_symbols = add_symbols;
 189
 190   ++i;
 191   tv[i].tv_tag = LDPT_GET_INPUT_FILE;
 192   tv[i].tv_u.tv_get_input_file = get_input_file;
 193
 194   ++i;
 195   tv[i].tv_tag = LDPT_GET_VIEW;
 196   tv[i].tv_u.tv_get_view = get_view;
 197
 198   ++i;
 199   tv[i].tv_tag = LDPT_RELEASE_INPUT_FILE;
 200   tv[i].tv_u.tv_release_input_file = release_input_file;
 201
 202   ++i;
 203   tv[i].tv_tag = LDPT_GET_SYMBOLS;
 204   tv[i].tv_u.tv_get_symbols = get_symbols;
 205
 206   ++i;
 207   tv[i].tv_tag = LDPT_ADD_INPUT_FILE;
 208   tv[i].tv_u.tv_add_input_file = add_input_file;
 209
 210   ++i;
 211   tv[i].tv_tag = LDPT_ADD_INPUT_LIBRARY;
 212   tv[i].tv_u.tv_add_input_library = add_input_library;
 213
 214   ++i;
 215   tv[i].tv_tag = LDPT_SET_EXTRA_LIBRARY_PATH;
 216   tv[i].tv_u.tv_set_extra_library_path = set_extra_library_path;
 217
 218   ++i;
 219   tv[i].tv_tag = LDPT_NULL;
 220   tv[i].tv_u.tv_val = 0;
 221
 222   gold_assert(i == tv_size - 1);
 223
 224   // Call the onload entry point.
 225   (*onload)(tv);
 226
 227   delete[] tv;
 228 #endif // ENABLE_PLUGINS
 229 }
 230
 231 // Call the plugin claim-file handler.
 232
 233 inline bool
 234 Plugin::claim_file(struct ld_plugin_input_file* plugin_input_file)
 235 {
 236   int claimed = 0;
 237
 238   if (this->claim_file_handler_ != NULL)
 239     {
 240       (*this->claim_file_handler_)(plugin_input_file, &claimed);
 241       if (claimed)
 242         return true;
 243     }
 244   return false;
 245 }
 246
 247 // Call the all-symbols-read handler.
 248
 249 inline void
 250 Plugin::all_symbols_read()
 251 {
 252   if (this->all_symbols_read_handler_ != NULL)
 253     (*this->all_symbols_read_handler_)();
 254 }
 255
 256 // Call the cleanup handler.
 257
 258 inline void
 259 Plugin::cleanup()
 260 {
 261   if (this->cleanup_handler_ != NULL && !this->cleanup_done_)
 262     {
 263       // Set this flag before calling to prevent a recursive plunge
 264       // in the event that a plugin's cleanup handler issues a
 265       // fatal error.
 266       this->cleanup_done_ = true;
 267       (*this->cleanup_handler_)();
 268     }
 269 }
 270
 271 // This task is used to rescan archives as needed.
 272
 273 class Plugin_rescan : public Task
 274 {
 275  public:
 276   Plugin_rescan(Task_token* this_blocker, Task_token* next_blocker)
 277     : this_blocker_(this_blocker), next_blocker_(next_blocker)
 278   { }
 279
 280   ~Plugin_rescan()
 281   {
 282     delete this->this_blocker_;
 283   }
 284
 285   Task_token*
 286   is_runnable()
 287   {
 288     if (this->this_blocker_->is_blocked())
 289       return this->this_blocker_;
 290     return NULL;
 291   }
 292
 293   void
 294   locks(Task_locker* tl)
 295   { tl->add(this, this->next_blocker_); }
 296
 297   void
 298   run(Workqueue*)
 299   { parameters->options().plugins()->rescan(this); }
 300
 301   std::string
 302   get_name() const
 303   { return "Plugin_rescan"; }
 304
 305  private:
 306   Task_token* this_blocker_;
 307   Task_token* next_blocker_;
 308 };
 309
 310 // Plugin_manager methods.
 311
 312 Plugin_manager::~Plugin_manager()
 313 {
 314   for (Plugin_list::iterator p = this->plugins_.begin();
 315        p != this->plugins_.end();
 316        ++p)
 317     delete *p;
 318   this->plugins_.clear();
 319   for (Object_list::iterator obj = this->objects_.begin();
 320        obj != this->objects_.end();
 321        ++obj)
 322     delete *obj;
 323   this->objects_.clear();
 324 }
 325
 326 // Load all plugin libraries.
 327
 328 void
 329 Plugin_manager::load_plugins()
 330 {
 331   for (this->current_ = this->plugins_.begin();
 332        this->current_ != this->plugins_.end();
 333        ++this->current_)
 334     (*this->current_)->load();
 335 }
 336
 337 // Call the plugin claim-file handlers in turn to see if any claim the file.
 338
 339 Pluginobj*
 340 Plugin_manager::claim_file(Input_file* input_file, off_t offset,
 341                            off_t filesize)
 342 {
 343   if (this->in_replacement_phase_)
 344     return NULL;
 345
 346   unsigned int handle = this->objects_.size();
 347   this->input_file_ = input_file;
 348   this->plugin_input_file_.name = input_file->filename().c_str();
 349   this->plugin_input_file_.fd = input_file->file().descriptor();
 350   this->plugin_input_file_.offset = offset;
 351   this->plugin_input_file_.filesize = filesize;
 352   this->plugin_input_file_.handle = reinterpret_cast<void*>(handle);
 353
 354   for (this->current_ = this->plugins_.begin();
 355        this->current_ != this->plugins_.end();
 356        ++this->current_)
 357     {
 358       if ((*this->current_)->claim_file(&this->plugin_input_file_))
 359         {
 360           this->any_claimed_ = true;
 361
 362           if (this->objects_.size() > handle)
 363             return this->objects_[handle];
 364
 365           // If the plugin claimed the file but did not call the
 366           // add_symbols callback, we need to create the Pluginobj now.
 367           Pluginobj* obj = this->make_plugin_object(handle);
 368           return obj;
 369         }
 370     }
 371
 372   return NULL;
 373 }
 374
 375 // Save an archive.  This is used so that a plugin can add a file
 376 // which refers to a symbol which was not previously referenced.  In
 377 // that case we want to pretend that the symbol was referenced before,
 378 // and pull in the archive object.
 379
 380 void
 381 Plugin_manager::save_archive(Archive* archive)
 382 {
 383   if (this->in_replacement_phase_ || !this->any_claimed_)
 384     delete archive;
 385   else
 386     this->rescannable_.push_back(Rescannable(archive));
 387 }
 388
 389 // Save an Input_group.  This is like save_archive.
 390
 391 void
 392 Plugin_manager::save_input_group(Input_group* input_group)
 393 {
 394   if (this->in_replacement_phase_ || !this->any_claimed_)
 395     delete input_group;
 396   else
 397     this->rescannable_.push_back(Rescannable(input_group));
 398 }
 399
 400 // Call the all-symbols-read handlers.
 401
 402 void
 403 Plugin_manager::all_symbols_read(Workqueue* workqueue, Task* task,
 404                                  Input_objects* input_objects,
 405                                  Symbol_table* symtab, Layout* layout,
 406                                  Dirsearch* dirpath, Mapfile* mapfile,
 407                                  Task_token** last_blocker)
 408 {
 409   this->in_replacement_phase_ = true;
 410   this->workqueue_ = workqueue;
 411   this->task_ = task;
 412   this->input_objects_ = input_objects;
 413   this->symtab_ = symtab;
 414   this->layout_ = layout;
 415   this->dirpath_ = dirpath;
 416   this->mapfile_ = mapfile;
 417   this->this_blocker_ = NULL;
 418
 419   for (this->current_ = this->plugins_.begin();
 420        this->current_ != this->plugins_.end();
 421        ++this->current_)
 422     (*this->current_)->all_symbols_read();
 423
 424   if (this->any_added_)
 425     {
 426       Task_token* next_blocker = new Task_token(true);
 427       next_blocker->add_blocker();
 428       workqueue->queue(new Plugin_rescan(this->this_blocker_, next_blocker));
 429       this->this_blocker_ = next_blocker;
 430     }
 431
 432   *last_blocker = this->this_blocker_;
 433 }
 434
 435 // This is called when we see a new undefined symbol.  If we are in
 436 // the replacement phase, this means that we may need to rescan some
 437 // archives we have previously seen.
 438
 439 void
 440 Plugin_manager::new_undefined_symbol(Symbol* sym)
 441 {
 442   if (this->in_replacement_phase_)
 443     this->undefined_symbols_.push_back(sym);
 444 }
 445
 446 // Rescan archives as needed.  This handles the case where a new
 447 // object file added by a plugin has an undefined reference to some
 448 // symbol defined in an archive.
 449
 450 void
 451 Plugin_manager::rescan(Task* task)
 452 {
 453   size_t rescan_pos = 0;
 454   size_t rescan_size = this->rescannable_.size();
 455   while (!this->undefined_symbols_.empty())
 456     {
 457       if (rescan_pos >= rescan_size)
 458         {
 459           this->undefined_symbols_.clear();
 460           return;
 461         }
 462
 463       Undefined_symbol_list undefs;
 464       undefs.reserve(this->undefined_symbols_.size());
 465       this->undefined_symbols_.swap(undefs);
 466
 467       size_t min_rescan_pos = rescan_size;
 468
 469       for (Undefined_symbol_list::const_iterator p = undefs.begin();
 470            p != undefs.end();
 471            ++p)
 472         {
 473           if (!(*p)->is_undefined())
 474             continue;
 475
 476           this->undefined_symbols_.push_back(*p);
 477
 478           // Find the first rescan archive which defines this symbol,
 479           // starting at the current rescan position.  The rescan position
 480           // exists so that given -la -lb -lc we don't look for undefined
 481           // symbols in -lb back in -la, but instead get the definition
 482           // from -lc.  Don't bother to look past the current minimum
 483           // rescan position.
 484           for (size_t i = rescan_pos; i < min_rescan_pos; ++i)
 485             {
 486               if (this->rescannable_defines(i, *p))
 487                 {
 488                   min_rescan_pos = i;
 489                   break;
 490                 }
 491             }
 492         }
 493
 494       if (min_rescan_pos >= rescan_size)
 495         {
 496           // We didn't find any rescannable archives which define any
 497           // undefined symbols.
 498           return;
 499         }
 500
 501       const Rescannable& r(this->rescannable_[min_rescan_pos]);
 502       if (r.is_archive)
 503         {
 504           Task_lock_obj<Archive> tl(task, r.u.archive);
 505           r.u.archive->add_symbols(this->symtab_, this->layout_,
 506                                    this->input_objects_, this->mapfile_);
 507         }
 508       else
 509         {
 510           size_t next_saw_undefined = this->symtab_->saw_undefined();
 511           size_t saw_undefined;
 512           do
 513             {
 514               saw_undefined = next_saw_undefined;
 515
 516               for (Input_group::const_iterator p = r.u.input_group->begin();
 517                    p != r.u.input_group->end();
 518                    ++p)
 519                 {
 520                   Task_lock_obj<Archive> tl(task, *p);
 521
 522                   (*p)->add_symbols(this->symtab_, this->layout_,
 523                                     this->input_objects_, this->mapfile_);
 524                 }
 525
 526               next_saw_undefined = this->symtab_->saw_undefined();
 527             }
 528           while (saw_undefined != next_saw_undefined);
 529         }
 530
 531       for (size_t i = rescan_pos; i < min_rescan_pos + 1; ++i)
 532         {
 533           if (this->rescannable_[i].is_archive)
 534             delete this->rescannable_[i].u.archive;
 535           else
 536             delete this->rescannable_[i].u.input_group;
 537         }
 538
 539       rescan_pos = min_rescan_pos + 1;
 540     }
 541 }
 542
 543 // Return whether the rescannable at index I defines SYM.
 544
 545 bool
 546 Plugin_manager::rescannable_defines(size_t i, Symbol* sym)
 547 {
 548   const Rescannable& r(this->rescannable_[i]);
 549   if (r.is_archive)
 550     return r.u.archive->defines_symbol(sym);
 551   else
 552     {
 553       for (Input_group::const_iterator p = r.u.input_group->begin();
 554            p != r.u.input_group->end();
 555            ++p)
 556         {
 557           if ((*p)->defines_symbol(sym))
 558             return true;
 559         }
 560       return false;
 561     }
 562 }
 563
 564 // Layout deferred objects.
 565
 566 void
 567 Plugin_manager::layout_deferred_objects()
 568 {
 569   Deferred_layout_list::iterator obj;
 570
 571   for (obj = this->deferred_layout_objects_.begin();
 572        obj != this->deferred_layout_objects_.end();
 573        ++obj)
 574     {
 575       // Lock the object so we can read from it.  This is only called
 576       // single-threaded from queue_middle_tasks, so it is OK to lock.
 577       // Unfortunately we have no way to pass in a Task token.
 578       const Task* dummy_task = reinterpret_cast<const Task*>(-1);
 579       Task_lock_obj<Object> tl(dummy_task, *obj);
 580       (*obj)->layout_deferred_sections(this->layout_);
 581     }
 582 }
 583
 584 // Call the cleanup handlers.
 585
 586 void
 587 Plugin_manager::cleanup()
 588 {
 589   for (this->current_ = this->plugins_.begin();
 590        this->current_ != this->plugins_.end();
 591        ++this->current_)
 592     (*this->current_)->cleanup();
 593 }
 594
 595 // Make a new Pluginobj object.  This is called when the plugin calls
 596 // the add_symbols API.
 597
 598 Pluginobj*
 599 Plugin_manager::make_plugin_object(unsigned int handle)
 600 {
 601   // Make sure we aren't asked to make an object for the same handle twice.
 602   if (this->objects_.size() != handle)
 603     return NULL;
 604
 605   Pluginobj* obj = make_sized_plugin_object(this->input_file_,
 606                                             this->plugin_input_file_.offset,
 607                                             this->plugin_input_file_.filesize);
 608   this->objects_.push_back(obj);
 609   return obj;
 610 }
 611
 612 // Get the input file information with an open (possibly re-opened)
 613 // file descriptor.
 614
 615 ld_plugin_status
 616 Plugin_manager::get_input_file(unsigned int handle,
 617                                struct ld_plugin_input_file* file)
 618 {
 619   Pluginobj* obj = this->object(handle);
 620   if (obj == NULL)
 621     return LDPS_BAD_HANDLE;
 622
 623   obj->lock(this->task_);
 624   file->name = obj->filename().c_str();
 625   file->fd = obj->descriptor();
 626   file->offset = obj->offset();
 627   file->filesize = obj->filesize();
 628   file->handle = reinterpret_cast<void*>(handle);
 629   return LDPS_OK;
 630 }
 631
 632 // Release the input file.
 633
 634 ld_plugin_status
 635 Plugin_manager::release_input_file(unsigned int handle)
 636 {
 637   Pluginobj* obj = this->object(handle);
 638   if (obj == NULL)
 639     return LDPS_BAD_HANDLE;
 640
 641   obj->unlock(this->task_);
 642   return LDPS_OK;
 643 }
 644
 645 ld_plugin_status
 646 Plugin_manager::get_view(unsigned int handle, const void **viewp)
 647 {
 648   off_t offset;
 649   size_t filesize;
 650   Input_file *input_file;
 651   if (this->objects_.size() == handle)
 652     {
 653       // We are being called from the claim_file hook.
 654       const struct ld_plugin_input_file &f = this->plugin_input_file_;
 655       offset = f.offset;
 656       filesize = f.filesize;
 657       input_file = this->input_file_;
 658     }
 659   else
 660     {
 661       // An already claimed file.
 662       Pluginobj* obj = this->object(handle);
 663       if (obj == NULL)
 664         return LDPS_BAD_HANDLE;
 665       offset = obj->offset();
 666       filesize = obj->filesize();
 667       input_file = obj->input_file();
 668     }
 669   *viewp = (void*) input_file->file().get_view(offset, 0, filesize, false,
 670                                                false);
 671   return LDPS_OK;
 672 }
 673
 674 // Add a new library path.
 675
 676 ld_plugin_status
 677 Plugin_manager::set_extra_library_path(const char* path)
 678 {
 679   this->extra_search_path_ = std::string(path);
 680   return LDPS_OK;
 681 }
 682
 683 // Add a new input file.
 684
 685 ld_plugin_status
 686 Plugin_manager::add_input_file(const char* pathname, bool is_lib)
 687 {
 688   Input_file_argument file(pathname,
 689                            (is_lib
 690                             ? Input_file_argument::INPUT_FILE_TYPE_LIBRARY
 691                             : Input_file_argument::INPUT_FILE_TYPE_FILE),
 692                            (is_lib
 693                             ? this->extra_search_path_.c_str()
 694                             : ""),
 695                            false,
 696                            this->options_);
 697   Input_argument* input_argument = new Input_argument(file);
 698   Task_token* next_blocker = new Task_token(true);
 699   next_blocker->add_blocker();
 700   if (parameters->incremental())
 701     gold_error(_("input files added by plug-ins in --incremental mode not "
 702                  "supported yet"));
 703   this->workqueue_->queue_soon(new Read_symbols(this->input_objects_,
 704                                                 this->symtab_,
 705                                                 this->layout_,
 706                                                 this->dirpath_,
 707                                                 0,
 708                                                 this->mapfile_,
 709                                                 input_argument,
 710                                                 NULL,
 711                                                 NULL,
 712                                                 this->this_blocker_,
 713                                                 next_blocker));
 714   this->this_blocker_ = next_blocker;
 715   this->any_added_ = true;
 716   return LDPS_OK;
 717 }
 718
 719 // Class Pluginobj.
 720
 721 Pluginobj::Pluginobj(const std::string& name, Input_file* input_file,
 722                      off_t offset, off_t filesize)
 723   : Object(name, input_file, false, offset),
 724     nsyms_(0), syms_(NULL), symbols_(), filesize_(filesize), comdat_map_()
 725 {
 726 }
 727
 728 // Return TRUE if a defined symbol might be reachable from outside the
 729 // universe of claimed objects.
 730
 731 static inline bool
 732 is_visible_from_outside(Symbol* lsym)
 733 {
 734   if (lsym->in_real_elf())
 735     return true;
 736   if (parameters->options().relocatable())
 737     return true;
 738   if (parameters->options().is_undefined(lsym->name()))
 739     return true;
 740   if (parameters->options().export_dynamic() || parameters->options().shared())
 741     return lsym->is_externally_visible();
 742   return false;
 743 }
 744
 745 // Get symbol resolution info.
 746
 747 ld_plugin_status
 748 Pluginobj::get_symbol_resolution_info(int nsyms, ld_plugin_symbol* syms) const
 749 {
 750   if (nsyms > this->nsyms_)
 751     return LDPS_NO_SYMS;
 752
 753   if (static_cast<size_t>(nsyms) > this->symbols_.size())
 754     {
 755       // We never decided to include this object. We mark all symbols as
 756       // preempted.
 757       gold_assert(this->symbols_.size() == 0);
 758       for (int i = 0; i < nsyms; i++)
 759         syms[i].resolution = LDPR_PREEMPTED_REG;
 760       return LDPS_OK;
 761     }
 762
 763   for (int i = 0; i < nsyms; i++)
 764     {
 765       ld_plugin_symbol* isym = &syms[i];
 766       Symbol* lsym = this->symbols_[i];
 767       ld_plugin_symbol_resolution res = LDPR_UNKNOWN;
 768
 769       if (lsym->is_undefined())
 770         // The symbol remains undefined.
 771         res = LDPR_UNDEF;
 772       else if (isym->def == LDPK_UNDEF
 773                || isym->def == LDPK_WEAKUNDEF
 774                || isym->def == LDPK_COMMON)
 775         {
 776           // The original symbol was undefined or common.
 777           if (lsym->source() != Symbol::FROM_OBJECT)
 778             res = LDPR_RESOLVED_EXEC;
 779           else if (lsym->object()->pluginobj() == this)
 780             res = (is_visible_from_outside(lsym)
 781                    ? LDPR_PREVAILING_DEF
 782                    : LDPR_PREVAILING_DEF_IRONLY);
 783           else if (lsym->object()->pluginobj() != NULL)
 784             res = LDPR_RESOLVED_IR;
 785           else if (lsym->object()->is_dynamic())
 786             res = LDPR_RESOLVED_DYN;
 787           else
 788             res = LDPR_RESOLVED_EXEC;
 789         }
 790       else
 791         {
 792           // The original symbol was a definition.
 793           if (lsym->source() != Symbol::FROM_OBJECT)
 794             res = LDPR_PREEMPTED_REG;
 795           else if (lsym->object() == static_cast<const Object*>(this))
 796             res = (is_visible_from_outside(lsym)
 797                    ? LDPR_PREVAILING_DEF
 798                    : LDPR_PREVAILING_DEF_IRONLY);
 799           else
 800             res = (lsym->object()->pluginobj() != NULL
 801                    ? LDPR_PREEMPTED_IR
 802                    : LDPR_PREEMPTED_REG);
 803         }
 804       isym->resolution = res;
 805     }
 806   return LDPS_OK;
 807 }
 808
 809 // Return TRUE if the comdat group with key COMDAT_KEY from this object
 810 // should be kept.
 811
 812 bool
 813 Pluginobj::include_comdat_group(std::string comdat_key, Layout* layout)
 814 {
 815   std::pair<Comdat_map::iterator, bool> ins =
 816     this->comdat_map_.insert(std::make_pair(comdat_key, false));
 817
 818   // If this is the first time we've seen this comdat key, ask the
 819   // layout object whether it should be included.
 820   if (ins.second)
 821     ins.first->second = layout->find_or_add_kept_section(comdat_key,
 822                                                          NULL, 0, true,
 823                                                          true, NULL);
 824
 825   return ins.first->second;
 826 }
 827
 828 // Class Sized_pluginobj.
 829
 830 template<int size, bool big_endian>
 831 Sized_pluginobj<size, big_endian>::Sized_pluginobj(
 832     const std::string& name,
 833     Input_file* input_file,
 834     off_t offset,
 835     off_t filesize)
 836   : Pluginobj(name, input_file, offset, filesize)
 837 {
 838 }
 839
 840 // Read the symbols.  Not used for plugin objects.
 841
 842 template<int size, bool big_endian>
 843 void
 844 Sized_pluginobj<size, big_endian>::do_read_symbols(Read_symbols_data*)
 845 {
 846   gold_unreachable();
 847 }
 848
 849 // Lay out the input sections.  Not used for plugin objects.
 850
 851 template<int size, bool big_endian>
 852 void
 853 Sized_pluginobj<size, big_endian>::do_layout(Symbol_table*, Layout*,
 854                                              Read_symbols_data*)
 855 {
 856   gold_unreachable();
 857 }
 858
 859 // Add the symbols to the symbol table.
 860
 861 template<int size, bool big_endian>
 862 void
 863 Sized_pluginobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
 864                                                   Read_symbols_data*,
 865                                                   Layout* layout)
 866 {
 867   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
 868   unsigned char symbuf[sym_size];
 869   elfcpp::Sym<size, big_endian> sym(symbuf);
 870   elfcpp::Sym_write<size, big_endian> osym(symbuf);
 871
 872   typedef typename elfcpp::Elf_types<size>::Elf_WXword Elf_size_type;
 873
 874   this->symbols_.resize(this->nsyms_);
 875
 876   for (int i = 0; i < this->nsyms_; ++i)
 877     {
 878       const struct ld_plugin_symbol* isym = &this->syms_[i];
 879       const char* name = isym->name;
 880       const char* ver = isym->version;
 881       elfcpp::Elf_Half shndx;
 882       elfcpp::STB bind;
 883       elfcpp::STV vis;
 884
 885       if (name != NULL && name[0] == '\0')
 886         name = NULL;
 887       if (ver != NULL && ver[0] == '\0')
 888         ver = NULL;
 889
 890       switch (isym->def)
 891         {
 892         case LDPK_WEAKDEF:
 893         case LDPK_WEAKUNDEF:
 894           bind = elfcpp::STB_WEAK;
 895           break;
 896         case LDPK_DEF:
 897         case LDPK_UNDEF:
 898         case LDPK_COMMON:
 899         default:
 900           bind = elfcpp::STB_GLOBAL;
 901           break;
 902         }
 903
 904       switch (isym->def)
 905         {
 906         case LDPK_DEF:
 907         case LDPK_WEAKDEF:
 908           shndx = elfcpp::SHN_ABS;
 909           break;
 910         case LDPK_COMMON:
 911           shndx = elfcpp::SHN_COMMON;
 912           break;
 913         case LDPK_UNDEF:
 914         case LDPK_WEAKUNDEF:
 915         default:
 916           shndx = elfcpp::SHN_UNDEF;
 917           break;
 918         }
 919
 920       switch (isym->visibility)
 921         {
 922         case LDPV_PROTECTED:
 923           vis = elfcpp::STV_PROTECTED;
 924           break;
 925         case LDPV_INTERNAL:
 926           vis = elfcpp::STV_INTERNAL;
 927           break;
 928         case LDPV_HIDDEN:
 929           vis = elfcpp::STV_HIDDEN;
 930           break;
 931         case LDPV_DEFAULT:
 932         default:
 933           vis = elfcpp::STV_DEFAULT;
 934           break;
 935         }
 936
 937       if (isym->comdat_key != NULL
 938           && isym->comdat_key[0] != '\0'
 939           && !this->include_comdat_group(isym->comdat_key, layout))
 940         shndx = elfcpp::SHN_UNDEF;
 941
 942       osym.put_st_name(0);
 943       osym.put_st_value(0);
 944       osym.put_st_size(static_cast<Elf_size_type>(isym->size));
 945       osym.put_st_info(bind, elfcpp::STT_NOTYPE);
 946       osym.put_st_other(vis, 0);
 947       osym.put_st_shndx(shndx);
 948
 949       this->symbols_[i] =
 950         symtab->add_from_pluginobj<size, big_endian>(this, name, ver, &sym);
 951     }
 952 }
 953
 954 template<int size, bool big_endian>
 955 Archive::Should_include
 956 Sized_pluginobj<size, big_endian>::do_should_include_member(
 957     Symbol_table* symtab,
 958     Layout* layout,
 959     Read_symbols_data*,
 960     std::string* why)
 961 {
 962   char* tmpbuf = NULL;
 963   size_t tmpbuflen = 0;
 964
 965   for (int i = 0; i < this->nsyms_; ++i)
 966     {
 967       const struct ld_plugin_symbol& sym = this->syms_[i];
 968       const char* name = sym.name;
 969       Symbol* symbol;
 970       Archive::Should_include t = Archive::should_include_member(symtab,
 971                                                                  layout,
 972                                                                  name,
 973                                                                  &symbol, why,
 974                                                                  &tmpbuf,
 975                                                                  &tmpbuflen);
 976       if (t == Archive::SHOULD_INCLUDE_YES)
 977         {
 978           if (tmpbuf != NULL)
 979             free(tmpbuf);
 980           return t;
 981         }
 982     }
 983   if (tmpbuf != NULL)
 984     free(tmpbuf);
 985   return Archive::SHOULD_INCLUDE_UNKNOWN;
 986 }
 987
 988 // Iterate over global symbols, calling a visitor class V for each.
 989
 990 template<int size, bool big_endian>
 991 void
 992 Sized_pluginobj<size, big_endian>::do_for_all_global_symbols(
 993     Read_symbols_data*,
 994     Library_base::Symbol_visitor_base* v)
 995 {
 996   for (int i = 0; i < this->nsyms_; ++i)
 997     {
 998       const struct ld_plugin_symbol& sym = this->syms_[i];
 999       if (sym.def != LDPK_UNDEF)
1000         v->visit(sym.name);
1001     }
1002 }
1003
1004 // Iterate over local symbols, calling a visitor class V for each GOT offset
1005 // associated with a local symbol.
1006 template<int size, bool big_endian>
1007 void
1008 Sized_pluginobj<size, big_endian>::do_for_all_local_got_entries(
1009     Got_offset_list::Visitor*) const
1010 {
1011   gold_unreachable();
1012 }
1013
1014 // Get the size of a section.  Not used for plugin objects.
1015
1016 template<int size, bool big_endian>
1017 uint64_t
1018 Sized_pluginobj<size, big_endian>::do_section_size(unsigned int)
1019 {
1020   gold_unreachable();
1021   return 0;
1022 }
1023
1024 // Get the name of a section.  Not used for plugin objects.
1025
1026 template<int size, bool big_endian>
1027 std::string
1028 Sized_pluginobj<size, big_endian>::do_section_name(unsigned int)
1029 {
1030   gold_unreachable();
1031   return std::string();
1032 }
1033
1034 // Return a view of the contents of a section.  Not used for plugin objects.
1035
1036 template<int size, bool big_endian>
1037 Object::Location
1038 Sized_pluginobj<size, big_endian>::do_section_contents(unsigned int)
1039 {
1040   Location loc(0, 0);
1041
1042   gold_unreachable();
1043   return loc;
1044 }
1045
1046 // Return section flags.  Not used for plugin objects.
1047
1048 template<int size, bool big_endian>
1049 uint64_t
1050 Sized_pluginobj<size, big_endian>::do_section_flags(unsigned int)
1051 {
1052   gold_unreachable();
1053   return 0;
1054 }
1055
1056 // Return section entsize.  Not used for plugin objects.
1057
1058 template<int size, bool big_endian>
1059 uint64_t
1060 Sized_pluginobj<size, big_endian>::do_section_entsize(unsigned int)
1061 {
1062   gold_unreachable();
1063   return 0;
1064 }
1065
1066 // Return section address.  Not used for plugin objects.
1067
1068 template<int size, bool big_endian>
1069 uint64_t
1070 Sized_pluginobj<size, big_endian>::do_section_address(unsigned int)
1071 {
1072   gold_unreachable();
1073   return 0;
1074 }
1075
1076 // Return section type.  Not used for plugin objects.
1077
1078 template<int size, bool big_endian>
1079 unsigned int
1080 Sized_pluginobj<size, big_endian>::do_section_type(unsigned int)
1081 {
1082   gold_unreachable();
1083   return 0;
1084 }
1085
1086 // Return the section link field.  Not used for plugin objects.
1087
1088 template<int size, bool big_endian>
1089 unsigned int
1090 Sized_pluginobj<size, big_endian>::do_section_link(unsigned int)
1091 {
1092   gold_unreachable();
1093   return 0;
1094 }
1095
1096 // Return the section link field.  Not used for plugin objects.
1097
1098 template<int size, bool big_endian>
1099 unsigned int
1100 Sized_pluginobj<size, big_endian>::do_section_info(unsigned int)
1101 {
1102   gold_unreachable();
1103   return 0;
1104 }
1105
1106 // Return the section alignment.  Not used for plugin objects.
1107
1108 template<int size, bool big_endian>
1109 uint64_t
1110 Sized_pluginobj<size, big_endian>::do_section_addralign(unsigned int)
1111 {
1112   gold_unreachable();
1113   return 0;
1114 }
1115
1116 // Return the Xindex structure to use.  Not used for plugin objects.
1117
1118 template<int size, bool big_endian>
1119 Xindex*
1120 Sized_pluginobj<size, big_endian>::do_initialize_xindex()
1121 {
1122   gold_unreachable();
1123   return NULL;
1124 }
1125
1126 // Get symbol counts.  Not used for plugin objects.
1127
1128 template<int size, bool big_endian>
1129 void
1130 Sized_pluginobj<size, big_endian>::do_get_global_symbol_counts(const Symbol_table*,
1131                                                    size_t*, size_t*) const
1132 {
1133   gold_unreachable();
1134 }
1135
1136 // Get symbols.  Not used for plugin objects.
1137
1138 template<int size, bool big_endian>
1139 const Object::Symbols*
1140 Sized_pluginobj<size, big_endian>::do_get_global_symbols() const
1141 {
1142   gold_unreachable();
1143 }
1144
1145 // Class Plugin_finish.  This task runs after all replacement files have
1146 // been added.  For now, it's a placeholder for a possible plugin API
1147 // to allow the plugin to release most of its resources.  The cleanup
1148 // handlers must be called later, because they can remove the temporary
1149 // object files that are needed until the end of the link.
1150
1151 class Plugin_finish : public Task
1152 {
1153  public:
1154   Plugin_finish(Task_token* this_blocker, Task_token* next_blocker)
1155     : this_blocker_(this_blocker), next_blocker_(next_blocker)
1156   { }
1157
1158   ~Plugin_finish()
1159   {
1160     if (this->this_blocker_ != NULL)
1161       delete this->this_blocker_;
1162   }
1163
1164   Task_token*
1165   is_runnable()
1166   {
1167     if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
1168       return this->this_blocker_;
1169     return NULL;
1170   }
1171
1172   void
1173   locks(Task_locker* tl)
1174   { tl->add(this, this->next_blocker_); }
1175
1176   void
1177   run(Workqueue*)
1178   {
1179     // We could call early cleanup handlers here.
1180   }
1181
1182   std::string
1183   get_name() const
1184   { return "Plugin_finish"; }
1185
1186  private:
1187   Task_token* this_blocker_;
1188   Task_token* next_blocker_;
1189 };
1190
1191 // Class Plugin_hook.
1192
1193 Plugin_hook::~Plugin_hook()
1194 {
1195 }
1196
1197 // Return whether a Plugin_hook task is runnable.
1198
1199 Task_token*
1200 Plugin_hook::is_runnable()
1201 {
1202   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
1203     return this->this_blocker_;
1204   return NULL;
1205 }
1206
1207 // Return a Task_locker for a Plugin_hook task.  We don't need any
1208 // locks here.
1209
1210 void
1211 Plugin_hook::locks(Task_locker*)
1212 {
1213 }
1214
1215 // Run the "all symbols read" plugin hook.
1216
1217 void
1218 Plugin_hook::run(Workqueue* workqueue)
1219 {
1220   gold_assert(this->options_.has_plugins());
1221   Symbol* start_sym;
1222   if (parameters->options().entry())
1223     start_sym = this->symtab_->lookup(parameters->options().entry());
1224   else
1225     start_sym = this->symtab_->lookup("_start");
1226   if (start_sym != NULL)
1227     start_sym->set_in_real_elf();
1228
1229   this->options_.plugins()->all_symbols_read(workqueue,
1230                                              this,
1231                                              this->input_objects_,
1232                                              this->symtab_,
1233                                              this->layout_,
1234                                              this->dirpath_,
1235                                              this->mapfile_,
1236                                              &this->this_blocker_);
1237   workqueue->queue_soon(new Plugin_finish(this->this_blocker_,
1238                                           this->next_blocker_));
1239 }
1240
1241 // The C interface routines called by the plugins.
1242
1243 #ifdef ENABLE_PLUGINS
1244
1245 // Register a claim-file handler.
1246
1247 static enum ld_plugin_status
1248 register_claim_file(ld_plugin_claim_file_handler handler)
1249 {
1250   gold_assert(parameters->options().has_plugins());
1251   parameters->options().plugins()->set_claim_file_handler(handler);
1252   return LDPS_OK;
1253 }
1254
1255 // Register an all-symbols-read handler.
1256
1257 static enum ld_plugin_status
1258 register_all_symbols_read(ld_plugin_all_symbols_read_handler handler)
1259 {
1260   gold_assert(parameters->options().has_plugins());
1261   parameters->options().plugins()->set_all_symbols_read_handler(handler);
1262   return LDPS_OK;
1263 }
1264
1265 // Register a cleanup handler.
1266
1267 static enum ld_plugin_status
1268 register_cleanup(ld_plugin_cleanup_handler handler)
1269 {
1270   gold_assert(parameters->options().has_plugins());
1271   parameters->options().plugins()->set_cleanup_handler(handler);
1272   return LDPS_OK;
1273 }
1274
1275 // Add symbols from a plugin-claimed input file.
1276
1277 static enum ld_plugin_status
1278 add_symbols(void* handle, int nsyms, const ld_plugin_symbol* syms)
1279 {
1280   gold_assert(parameters->options().has_plugins());
1281   Pluginobj* obj = parameters->options().plugins()->make_plugin_object(
1282       static_cast<unsigned int>(reinterpret_cast<intptr_t>(handle)));
1283   if (obj == NULL)
1284     return LDPS_ERR;
1285   obj->store_incoming_symbols(nsyms, syms);
1286   return LDPS_OK;
1287 }
1288
1289 // Get the input file information with an open (possibly re-opened)
1290 // file descriptor.
1291
1292 static enum ld_plugin_status
1293 get_input_file(const void* handle, struct ld_plugin_input_file* file)
1294 {
1295   gold_assert(parameters->options().has_plugins());
1296   unsigned int obj_index =
1297       static_cast<unsigned int>(reinterpret_cast<intptr_t>(handle));
1298   return parameters->options().plugins()->get_input_file(obj_index, file);
1299 }
1300
1301 // Release the input file.
1302
1303 static enum ld_plugin_status
1304 release_input_file(const void* handle)
1305 {
1306   gold_assert(parameters->options().has_plugins());
1307   unsigned int obj_index =
1308       static_cast<unsigned int>(reinterpret_cast<intptr_t>(handle));
1309   return parameters->options().plugins()->release_input_file(obj_index);
1310 }
1311
1312 static enum ld_plugin_status
1313 get_view(const void *handle, const void **viewp)
1314 {
1315   gold_assert(parameters->options().has_plugins());
1316   unsigned int obj_index =
1317       static_cast<unsigned int>(reinterpret_cast<intptr_t>(handle));
1318   return parameters->options().plugins()->get_view(obj_index, viewp);
1319 }
1320
1321 // Get the symbol resolution info for a plugin-claimed input file.
1322
1323 static enum ld_plugin_status
1324 get_symbols(const void* handle, int nsyms, ld_plugin_symbol* syms)
1325 {
1326   gold_assert(parameters->options().has_plugins());
1327   Pluginobj* obj = parameters->options().plugins()->object(
1328       static_cast<unsigned int>(reinterpret_cast<intptr_t>(handle)));
1329   if (obj == NULL)
1330     return LDPS_ERR;
1331   return obj->get_symbol_resolution_info(nsyms, syms);
1332 }
1333
1334 // Add a new (real) input file generated by a plugin.
1335
1336 static enum ld_plugin_status
1337 add_input_file(const char* pathname)
1338 {
1339   gold_assert(parameters->options().has_plugins());
1340   return parameters->options().plugins()->add_input_file(pathname, false);
1341 }
1342
1343 // Add a new (real) library required by a plugin.
1344
1345 static enum ld_plugin_status
1346 add_input_library(const char* pathname)
1347 {
1348   gold_assert(parameters->options().has_plugins());
1349   return parameters->options().plugins()->add_input_file(pathname, true);
1350 }
1351
1352 // Set the extra library path to be used by libraries added via
1353 // add_input_library
1354
1355 static enum ld_plugin_status
1356 set_extra_library_path(const char* path)
1357 {
1358   gold_assert(parameters->options().has_plugins());
1359   return parameters->options().plugins()->set_extra_library_path(path);
1360 }
1361
1362 // Issue a diagnostic message from a plugin.
1363
1364 static enum ld_plugin_status
1365 message(int level, const char* format, ...)
1366 {
1367   va_list args;
1368   va_start(args, format);
1369
1370   switch (level)
1371     {
1372     case LDPL_INFO:
1373       parameters->errors()->info(format, args);
1374       break;
1375     case LDPL_WARNING:
1376       parameters->errors()->warning(format, args);
1377       break;
1378     case LDPL_ERROR:
1379     default:
1380       parameters->errors()->error(format, args);
1381       break;
1382     case LDPL_FATAL:
1383       parameters->errors()->fatal(format, args);
1384       break;
1385     }
1386
1387   va_end(args);
1388   return LDPS_OK;
1389 }
1390
1391 #endif // ENABLE_PLUGINS
1392
1393 // Allocate a Pluginobj object of the appropriate size and endianness.
1394
1395 static Pluginobj*
1396 make_sized_plugin_object(Input_file* input_file, off_t offset, off_t filesize)
1397 {
1398   Pluginobj* obj = NULL;
1399
1400   parameters_force_valid_target();
1401   const Target& target(parameters->target());
1402
1403   if (target.get_size() == 32)
1404     {
1405       if (target.is_big_endian())
1406 #ifdef HAVE_TARGET_32_BIG
1407         obj = new Sized_pluginobj<32, true>(input_file->filename(),
1408                                             input_file, offset, filesize);
1409 #else
1410         gold_error(_("%s: not configured to support "
1411                      "32-bit big-endian object"),
1412                    input_file->filename().c_str());
1413 #endif
1414       else
1415 #ifdef HAVE_TARGET_32_LITTLE
1416         obj = new Sized_pluginobj<32, false>(input_file->filename(),
1417                                              input_file, offset, filesize);
1418 #else
1419         gold_error(_("%s: not configured to support "
1420                      "32-bit little-endian object"),
1421                    input_file->filename().c_str());
1422 #endif
1423     }
1424   else if (target.get_size() == 64)
1425     {
1426       if (target.is_big_endian())
1427 #ifdef HAVE_TARGET_64_BIG
1428         obj = new Sized_pluginobj<64, true>(input_file->filename(),
1429                                             input_file, offset, filesize);
1430 #else
1431         gold_error(_("%s: not configured to support "
1432                      "64-bit big-endian object"),
1433                    input_file->filename().c_str());
1434 #endif
1435       else
1436 #ifdef HAVE_TARGET_64_LITTLE
1437         obj = new Sized_pluginobj<64, false>(input_file->filename(),
1438                                              input_file, offset, filesize);
1439 #else
1440         gold_error(_("%s: not configured to support "
1441                      "64-bit little-endian object"),
1442                    input_file->filename().c_str());
1443 #endif
1444     }
1445
1446   gold_assert(obj != NULL);
1447   return obj;
1448 }
1449
1450 } // End namespace gold.