PR gold/10708
[platform/upstream/binutils.git] / gold / plugin.cc
1 // plugin.cc -- plugin manager for gold      -*- C++ -*-
2
3 // Copyright 2008, 2009, 2010 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 release_input_file(const void *handle);
73
74 static enum ld_plugin_status
75 get_symbols(const void *handle, int nsyms, struct ld_plugin_symbol *syms);
76
77 static enum ld_plugin_status
78 add_input_file(const char *pathname);
79
80 static enum ld_plugin_status
81 add_input_library(const char *pathname);
82
83 static enum ld_plugin_status
84 set_extra_library_path(const char *path);
85
86 static enum ld_plugin_status
87 message(int level, const char *format, ...);
88
89 };
90
91 #endif // ENABLE_PLUGINS
92
93 static Pluginobj* make_sized_plugin_object(Input_file* input_file,
94                                            off_t offset, off_t filesize);
95
96 // Plugin methods.
97
98 // Load one plugin library.
99
100 void
101 Plugin::load()
102 {
103 #ifdef ENABLE_PLUGINS
104   // Load the plugin library.
105   // FIXME: Look for the library in standard locations.
106   this->handle_ = dlopen(this->filename_.c_str(), RTLD_NOW);
107   if (this->handle_ == NULL)
108     {
109       gold_error(_("%s: could not load plugin library: %s"),
110                  this->filename_.c_str(), dlerror());
111       return;
112     }
113
114   // Find the plugin's onload entry point.
115   void* ptr = dlsym(this->handle_, "onload");
116   if (ptr == NULL)
117     {
118       gold_error(_("%s: could not find onload entry point"),
119                  this->filename_.c_str());
120       return;
121     }
122   ld_plugin_onload onload;
123   gold_assert(sizeof(onload) == sizeof(ptr));
124   memcpy(&onload, &ptr, sizeof(ptr));
125
126   // Get the linker's version number.
127   const char* ver = get_version_string();
128   int major = 0;
129   int minor = 0;
130   sscanf(ver, "%d.%d", &major, &minor);
131
132   // Allocate and populate a transfer vector.
133   const int tv_fixed_size = 16;
134   int tv_size = this->args_.size() + tv_fixed_size;
135   ld_plugin_tv* tv = new ld_plugin_tv[tv_size];
136
137   // Put LDPT_MESSAGE at the front of the list so the plugin can use it
138   // while processing subsequent entries.
139   int i = 0;
140   tv[i].tv_tag = LDPT_MESSAGE;
141   tv[i].tv_u.tv_message = message;
142
143   ++i;
144   tv[i].tv_tag = LDPT_API_VERSION;
145   tv[i].tv_u.tv_val = LD_PLUGIN_API_VERSION;
146
147   ++i;
148   tv[i].tv_tag = LDPT_GOLD_VERSION;
149   tv[i].tv_u.tv_val = major * 100 + minor;
150
151   ++i;
152   tv[i].tv_tag = LDPT_LINKER_OUTPUT;
153   if (parameters->options().relocatable())
154     tv[i].tv_u.tv_val = LDPO_REL;
155   else if (parameters->options().shared())
156     tv[i].tv_u.tv_val = LDPO_DYN;
157   else
158     tv[i].tv_u.tv_val = LDPO_EXEC;
159
160   ++i;
161   tv[i].tv_tag = LDPT_OUTPUT_NAME;
162   tv[i].tv_u.tv_string = parameters->options().output();
163
164   for (unsigned int j = 0; j < this->args_.size(); ++j)
165     {
166       ++i;
167       tv[i].tv_tag = LDPT_OPTION;
168       tv[i].tv_u.tv_string = this->args_[j].c_str();
169     }
170
171   ++i;
172   tv[i].tv_tag = LDPT_REGISTER_CLAIM_FILE_HOOK;
173   tv[i].tv_u.tv_register_claim_file = register_claim_file;
174
175   ++i;
176   tv[i].tv_tag = LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK;
177   tv[i].tv_u.tv_register_all_symbols_read = register_all_symbols_read;
178
179   ++i;
180   tv[i].tv_tag = LDPT_REGISTER_CLEANUP_HOOK;
181   tv[i].tv_u.tv_register_cleanup = register_cleanup;
182
183   ++i;
184   tv[i].tv_tag = LDPT_ADD_SYMBOLS;
185   tv[i].tv_u.tv_add_symbols = add_symbols;
186
187   ++i;
188   tv[i].tv_tag = LDPT_GET_INPUT_FILE;
189   tv[i].tv_u.tv_get_input_file = get_input_file;
190
191   ++i;
192   tv[i].tv_tag = LDPT_RELEASE_INPUT_FILE;
193   tv[i].tv_u.tv_release_input_file = release_input_file;
194
195   ++i;
196   tv[i].tv_tag = LDPT_GET_SYMBOLS;
197   tv[i].tv_u.tv_get_symbols = get_symbols;
198
199   ++i;
200   tv[i].tv_tag = LDPT_ADD_INPUT_FILE;
201   tv[i].tv_u.tv_add_input_file = add_input_file;
202
203   ++i;
204   tv[i].tv_tag = LDPT_ADD_INPUT_LIBRARY;
205   tv[i].tv_u.tv_add_input_library = add_input_library;
206
207   ++i;
208   tv[i].tv_tag = LDPT_SET_EXTRA_LIBRARY_PATH;
209   tv[i].tv_u.tv_set_extra_library_path = set_extra_library_path;
210
211   ++i;
212   tv[i].tv_tag = LDPT_NULL;
213   tv[i].tv_u.tv_val = 0;
214
215   gold_assert(i == tv_size - 1);
216
217   // Call the onload entry point.
218   (*onload)(tv);
219
220   delete[] tv;
221 #endif // ENABLE_PLUGINS
222 }
223
224 // Call the plugin claim-file handler.
225
226 inline bool
227 Plugin::claim_file(struct ld_plugin_input_file* plugin_input_file)
228 {
229   int claimed = 0;
230
231   if (this->claim_file_handler_ != NULL)
232     {
233       (*this->claim_file_handler_)(plugin_input_file, &claimed);
234       if (claimed)
235         return true;
236     }
237   return false;
238 }
239
240 // Call the all-symbols-read handler.
241
242 inline void
243 Plugin::all_symbols_read()
244 {
245   if (this->all_symbols_read_handler_ != NULL)
246     (*this->all_symbols_read_handler_)();
247 }
248
249 // Call the cleanup handler.
250
251 inline void
252 Plugin::cleanup()
253 {
254   if (this->cleanup_handler_ != NULL && !this->cleanup_done_)
255     {
256       // Set this flag before calling to prevent a recursive plunge
257       // in the event that a plugin's cleanup handler issues a
258       // fatal error.
259       this->cleanup_done_ = true;
260       (*this->cleanup_handler_)();
261     }
262 }
263
264 // Plugin_manager methods.
265
266 Plugin_manager::~Plugin_manager()
267 {
268   for (Plugin_list::iterator p = this->plugins_.begin();
269        p != this->plugins_.end();
270        ++p)
271     delete *p;
272   this->plugins_.clear();
273   for (Object_list::iterator obj = this->objects_.begin();
274        obj != this->objects_.end();
275        ++obj)
276     delete *obj;
277   this->objects_.clear();
278 }
279
280 // Load all plugin libraries.
281
282 void
283 Plugin_manager::load_plugins()
284 {
285   for (this->current_ = this->plugins_.begin();
286        this->current_ != this->plugins_.end();
287        ++this->current_)
288     (*this->current_)->load();
289 }
290
291 // Call the plugin claim-file handlers in turn to see if any claim the file.
292
293 Pluginobj*
294 Plugin_manager::claim_file(Input_file* input_file, off_t offset,
295                            off_t filesize)
296 {
297   if (this->in_replacement_phase_)
298     return NULL;
299
300   unsigned int handle = this->objects_.size();
301   this->input_file_ = input_file;
302   this->plugin_input_file_.name = input_file->filename().c_str();
303   this->plugin_input_file_.fd = input_file->file().descriptor();
304   this->plugin_input_file_.offset = offset;
305   this->plugin_input_file_.filesize = filesize;
306   this->plugin_input_file_.handle = reinterpret_cast<void*>(handle);
307
308   for (this->current_ = this->plugins_.begin();
309        this->current_ != this->plugins_.end();
310        ++this->current_)
311     {
312       if ((*this->current_)->claim_file(&this->plugin_input_file_))
313         {
314           if (this->objects_.size() > handle)
315             return this->objects_[handle];
316
317           // If the plugin claimed the file but did not call the
318           // add_symbols callback, we need to create the Pluginobj now.
319           Pluginobj* obj = this->make_plugin_object(handle);
320           return obj;
321         }
322     }
323
324   return NULL;
325 }
326
327 // Call the all-symbols-read handlers.
328
329 void
330 Plugin_manager::all_symbols_read(Workqueue* workqueue, Task* task,
331                                  Input_objects* input_objects,
332                                  Symbol_table* symtab, Layout* layout,
333                                  Dirsearch* dirpath, Mapfile* mapfile,
334                                  Task_token** last_blocker)
335 {
336   this->in_replacement_phase_ = true;
337   this->workqueue_ = workqueue;
338   this->task_ = task;
339   this->input_objects_ = input_objects;
340   this->symtab_ = symtab;
341   this->layout_ = layout;
342   this->dirpath_ = dirpath;
343   this->mapfile_ = mapfile;
344   this->this_blocker_ = NULL;
345
346   for (this->current_ = this->plugins_.begin();
347        this->current_ != this->plugins_.end();
348        ++this->current_)
349     (*this->current_)->all_symbols_read();
350
351   *last_blocker = this->this_blocker_;
352 }
353
354 // Layout deferred objects.
355
356 void
357 Plugin_manager::layout_deferred_objects()
358 {
359   Deferred_layout_list::iterator obj;
360
361   for (obj = this->deferred_layout_objects_.begin();
362        obj != this->deferred_layout_objects_.end();
363        ++obj)
364     {
365       // Lock the object so we can read from it.  This is only called
366       // single-threaded from queue_middle_tasks, so it is OK to lock.
367       // Unfortunately we have no way to pass in a Task token.
368       const Task* dummy_task = reinterpret_cast<const Task*>(-1);
369       Task_lock_obj<Object> tl(dummy_task, *obj);
370       (*obj)->layout_deferred_sections(this->layout_);
371     }
372 }
373
374 // Call the cleanup handlers.
375
376 void
377 Plugin_manager::cleanup()
378 {
379   for (this->current_ = this->plugins_.begin();
380        this->current_ != this->plugins_.end();
381        ++this->current_)
382     (*this->current_)->cleanup();
383 }
384
385 // Make a new Pluginobj object.  This is called when the plugin calls
386 // the add_symbols API.
387
388 Pluginobj*
389 Plugin_manager::make_plugin_object(unsigned int handle)
390 {
391   // Make sure we aren't asked to make an object for the same handle twice.
392   if (this->objects_.size() != handle)
393     return NULL;
394
395   Pluginobj* obj = make_sized_plugin_object(this->input_file_,
396                                             this->plugin_input_file_.offset,
397                                             this->plugin_input_file_.filesize);
398   this->objects_.push_back(obj);
399   return obj;
400 }
401
402 // Get the input file information with an open (possibly re-opened)
403 // file descriptor.
404
405 ld_plugin_status
406 Plugin_manager::get_input_file(unsigned int handle,
407                                struct ld_plugin_input_file* file)
408 {
409   Pluginobj* obj = this->object(handle);
410   if (obj == NULL)
411     return LDPS_BAD_HANDLE;
412
413   obj->lock(this->task_);
414   file->name = obj->filename().c_str();
415   file->fd = obj->descriptor();
416   file->offset = obj->offset();
417   file->filesize = obj->filesize();
418   file->handle = reinterpret_cast<void*>(handle);
419   return LDPS_OK;
420 }
421
422 // Release the input file.
423
424 ld_plugin_status
425 Plugin_manager::release_input_file(unsigned int handle)
426 {
427   Pluginobj* obj = this->object(handle);
428   if (obj == NULL)
429     return LDPS_BAD_HANDLE;
430
431   obj->unlock(this->task_);
432   return LDPS_OK;
433 }
434
435 // Add a new library path.
436
437 ld_plugin_status
438 Plugin_manager::set_extra_library_path(const char* path)
439 {
440   this->extra_search_path_ = std::string(path);
441   return LDPS_OK;
442 }
443
444 // Add a new input file.
445
446 ld_plugin_status
447 Plugin_manager::add_input_file(const char* pathname, bool is_lib)
448 {
449   Input_file_argument file(pathname,
450                            (is_lib
451                             ? Input_file_argument::INPUT_FILE_TYPE_LIBRARY
452                             : Input_file_argument::INPUT_FILE_TYPE_FILE),
453                            (is_lib
454                             ? this->extra_search_path_.c_str()
455                             : ""),
456                            false,
457                            this->options_);
458   Input_argument* input_argument = new Input_argument(file);
459   Task_token* next_blocker = new Task_token(true);
460   next_blocker->add_blocker();
461   if (parameters->incremental())
462     gold_error(_("input files added by plug-ins in --incremental mode not "
463                  "supported yet"));
464   this->workqueue_->queue_soon(new Read_symbols(this->input_objects_,
465                                                 this->symtab_,
466                                                 this->layout_,
467                                                 this->dirpath_,
468                                                 0,
469                                                 this->mapfile_,
470                                                 input_argument,
471                                                 NULL,
472                                                 NULL,
473                                                 this->this_blocker_,
474                                                 next_blocker));
475   this->this_blocker_ = next_blocker;
476   return LDPS_OK;
477 }
478
479 // Class Pluginobj.
480
481 Pluginobj::Pluginobj(const std::string& name, Input_file* input_file,
482                      off_t offset, off_t filesize)
483   : Object(name, input_file, false, offset),
484     nsyms_(0), syms_(NULL), symbols_(), filesize_(filesize), comdat_map_()
485 {
486 }
487
488 // Return TRUE if a defined symbol might be reachable from outside the
489 // universe of claimed objects.
490
491 static inline bool
492 is_visible_from_outside(Symbol* lsym)
493 {
494   if (lsym->in_real_elf())
495     return true;
496   if (parameters->options().relocatable())
497     return true;
498   if (parameters->options().export_dynamic() || parameters->options().shared())
499     return lsym->is_externally_visible();
500   return false;
501 }
502
503 // Get symbol resolution info.
504
505 ld_plugin_status
506 Pluginobj::get_symbol_resolution_info(int nsyms, ld_plugin_symbol* syms) const
507 {
508   if (nsyms > this->nsyms_)
509     return LDPS_NO_SYMS;
510
511   if (static_cast<size_t>(nsyms) > this->symbols_.size())
512     {
513       // We never decided to include this object. We mark all symbols as
514       // preempted.
515       gold_assert(this->symbols_.size() == 0);
516       for (int i = 0; i < nsyms; i++)
517         syms[i].resolution = LDPR_PREEMPTED_REG;
518       return LDPS_OK;
519     }
520
521   for (int i = 0; i < nsyms; i++)
522     {
523       ld_plugin_symbol* isym = &syms[i];
524       Symbol* lsym = this->symbols_[i];
525       ld_plugin_symbol_resolution res = LDPR_UNKNOWN;
526
527       if (lsym->is_undefined())
528         // The symbol remains undefined.
529         res = LDPR_UNDEF;
530       else if (isym->def == LDPK_UNDEF
531                || isym->def == LDPK_WEAKUNDEF
532                || isym->def == LDPK_COMMON)
533         {
534           // The original symbol was undefined or common.
535           if (lsym->source() != Symbol::FROM_OBJECT)
536             res = LDPR_RESOLVED_EXEC;
537           else if (lsym->object()->pluginobj() == this)
538             res = (is_visible_from_outside(lsym)
539                    ? LDPR_PREVAILING_DEF
540                    : LDPR_PREVAILING_DEF_IRONLY);
541           else if (lsym->object()->pluginobj() != NULL)
542             res = LDPR_RESOLVED_IR;
543           else if (lsym->object()->is_dynamic())
544             res = LDPR_RESOLVED_DYN;
545           else
546             res = LDPR_RESOLVED_EXEC;
547         }
548       else
549         {
550           // The original symbol was a definition.
551           if (lsym->source() != Symbol::FROM_OBJECT)
552             res = LDPR_PREEMPTED_REG;
553           else if (lsym->object() == static_cast<const Object*>(this))
554             res = (is_visible_from_outside(lsym)
555                    ? LDPR_PREVAILING_DEF
556                    : LDPR_PREVAILING_DEF_IRONLY);
557           else
558             res = (lsym->object()->pluginobj() != NULL
559                    ? LDPR_PREEMPTED_IR
560                    : LDPR_PREEMPTED_REG);
561         }
562       isym->resolution = res;
563     }
564   return LDPS_OK;
565 }
566
567 // Return TRUE if the comdat group with key COMDAT_KEY from this object
568 // should be kept.
569
570 bool
571 Pluginobj::include_comdat_group(std::string comdat_key, Layout* layout)
572 {
573   std::pair<Comdat_map::iterator, bool> ins =
574     this->comdat_map_.insert(std::make_pair(comdat_key, false));
575
576   // If this is the first time we've seen this comdat key, ask the
577   // layout object whether it should be included.
578   if (ins.second)
579     ins.first->second = layout->find_or_add_kept_section(comdat_key,
580                                                          NULL, 0, true,
581                                                          true, NULL);
582
583   return ins.first->second;
584 }
585
586 // Class Sized_pluginobj.
587
588 template<int size, bool big_endian>
589 Sized_pluginobj<size, big_endian>::Sized_pluginobj(
590     const std::string& name,
591     Input_file* input_file,
592     off_t offset,
593     off_t filesize)
594   : Pluginobj(name, input_file, offset, filesize)
595 {
596 }
597
598 // Read the symbols.  Not used for plugin objects.
599
600 template<int size, bool big_endian>
601 void
602 Sized_pluginobj<size, big_endian>::do_read_symbols(Read_symbols_data*)
603 {
604   gold_unreachable();
605 }
606
607 // Lay out the input sections.  Not used for plugin objects.
608
609 template<int size, bool big_endian>
610 void
611 Sized_pluginobj<size, big_endian>::do_layout(Symbol_table*, Layout*,
612                                              Read_symbols_data*)
613 {
614   gold_unreachable();
615 }
616
617 // Add the symbols to the symbol table.
618
619 template<int size, bool big_endian>
620 void
621 Sized_pluginobj<size, big_endian>::do_add_symbols(Symbol_table* symtab,
622                                                   Read_symbols_data*,
623                                                   Layout* layout)
624 {
625   const int sym_size = elfcpp::Elf_sizes<size>::sym_size;
626   unsigned char symbuf[sym_size];
627   elfcpp::Sym<size, big_endian> sym(symbuf);
628   elfcpp::Sym_write<size, big_endian> osym(symbuf);
629
630   typedef typename elfcpp::Elf_types<size>::Elf_WXword Elf_size_type;
631
632   this->symbols_.resize(this->nsyms_);
633
634   for (int i = 0; i < this->nsyms_; ++i)
635     {
636       const struct ld_plugin_symbol* isym = &this->syms_[i];
637       const char* name = isym->name;
638       const char* ver = isym->version;
639       elfcpp::Elf_Half shndx;
640       elfcpp::STB bind;
641       elfcpp::STV vis;
642
643       if (name != NULL && name[0] == '\0')
644         name = NULL;
645       if (ver != NULL && ver[0] == '\0')
646         ver = NULL;
647
648       switch (isym->def)
649         {
650         case LDPK_WEAKDEF:
651         case LDPK_WEAKUNDEF:
652           bind = elfcpp::STB_WEAK;
653           break;
654         case LDPK_DEF:
655         case LDPK_UNDEF:
656         case LDPK_COMMON:
657         default:
658           bind = elfcpp::STB_GLOBAL;
659           break;
660         }
661
662       switch (isym->def)
663         {
664         case LDPK_DEF:
665         case LDPK_WEAKDEF:
666           shndx = elfcpp::SHN_ABS;
667           break;
668         case LDPK_COMMON:
669           shndx = elfcpp::SHN_COMMON;
670           break;
671         case LDPK_UNDEF:
672         case LDPK_WEAKUNDEF:
673         default:
674           shndx = elfcpp::SHN_UNDEF;
675           break;
676         }
677
678       switch (isym->visibility)
679         {
680         case LDPV_PROTECTED:
681           vis = elfcpp::STV_PROTECTED;
682           break;
683         case LDPV_INTERNAL:
684           vis = elfcpp::STV_INTERNAL;
685           break;
686         case LDPV_HIDDEN:
687           vis = elfcpp::STV_HIDDEN;
688           break;
689         case LDPV_DEFAULT:
690         default:
691           vis = elfcpp::STV_DEFAULT;
692           break;
693         }
694
695       if (isym->comdat_key != NULL
696           && isym->comdat_key[0] != '\0'
697           && !this->include_comdat_group(isym->comdat_key, layout))
698         shndx = elfcpp::SHN_UNDEF;
699
700       osym.put_st_name(0);
701       osym.put_st_value(0);
702       osym.put_st_size(static_cast<Elf_size_type>(isym->size));
703       osym.put_st_info(bind, elfcpp::STT_NOTYPE);
704       osym.put_st_other(vis, 0);
705       osym.put_st_shndx(shndx);
706
707       this->symbols_[i] =
708         symtab->add_from_pluginobj<size, big_endian>(this, name, ver, &sym);
709     }
710 }
711
712 template<int size, bool big_endian>
713 Archive::Should_include
714 Sized_pluginobj<size, big_endian>::do_should_include_member(
715     Symbol_table* symtab,
716     Layout* layout,
717     Read_symbols_data*,
718     std::string* why)
719 {
720   char* tmpbuf = NULL;
721   size_t tmpbuflen = 0;
722
723   for (int i = 0; i < this->nsyms_; ++i)
724     {
725       const struct ld_plugin_symbol& sym = this->syms_[i];
726       const char* name = sym.name;
727       Symbol* symbol;
728       Archive::Should_include t = Archive::should_include_member(symtab,
729                                                                  layout,
730                                                                  name,
731                                                                  &symbol, why,
732                                                                  &tmpbuf,
733                                                                  &tmpbuflen);
734       if (t == Archive::SHOULD_INCLUDE_YES)
735         {
736           if (tmpbuf != NULL)
737             free(tmpbuf);
738           return t;
739         }
740     }
741   if (tmpbuf != NULL)
742     free(tmpbuf);
743   return Archive::SHOULD_INCLUDE_UNKNOWN;
744 }
745
746 // Get the size of a section.  Not used for plugin objects.
747
748 template<int size, bool big_endian>
749 uint64_t
750 Sized_pluginobj<size, big_endian>::do_section_size(unsigned int)
751 {
752   gold_unreachable();
753   return 0;
754 }
755
756 // Get the name of a section.  Not used for plugin objects.
757
758 template<int size, bool big_endian>
759 std::string
760 Sized_pluginobj<size, big_endian>::do_section_name(unsigned int)
761 {
762   gold_unreachable();
763   return std::string();
764 }
765
766 // Return a view of the contents of a section.  Not used for plugin objects.
767
768 template<int size, bool big_endian>
769 Object::Location
770 Sized_pluginobj<size, big_endian>::do_section_contents(unsigned int)
771 {
772   Location loc(0, 0);
773
774   gold_unreachable();
775   return loc;
776 }
777
778 // Return section flags.  Not used for plugin objects.
779
780 template<int size, bool big_endian>
781 uint64_t
782 Sized_pluginobj<size, big_endian>::do_section_flags(unsigned int)
783 {
784   gold_unreachable();
785   return 0;
786 }
787
788 // Return section entsize.  Not used for plugin objects.
789
790 template<int size, bool big_endian>
791 uint64_t
792 Sized_pluginobj<size, big_endian>::do_section_entsize(unsigned int)
793 {
794   gold_unreachable();
795   return 0;
796 }
797
798 // Return section address.  Not used for plugin objects.
799
800 template<int size, bool big_endian>
801 uint64_t
802 Sized_pluginobj<size, big_endian>::do_section_address(unsigned int)
803 {
804   gold_unreachable();
805   return 0;
806 }
807
808 // Return section type.  Not used for plugin objects.
809
810 template<int size, bool big_endian>
811 unsigned int
812 Sized_pluginobj<size, big_endian>::do_section_type(unsigned int)
813 {
814   gold_unreachable();
815   return 0;
816 }
817
818 // Return the section link field.  Not used for plugin objects.
819
820 template<int size, bool big_endian>
821 unsigned int
822 Sized_pluginobj<size, big_endian>::do_section_link(unsigned int)
823 {
824   gold_unreachable();
825   return 0;
826 }
827
828 // Return the section link field.  Not used for plugin objects.
829
830 template<int size, bool big_endian>
831 unsigned int
832 Sized_pluginobj<size, big_endian>::do_section_info(unsigned int)
833 {
834   gold_unreachable();
835   return 0;
836 }
837
838 // Return the section alignment.  Not used for plugin objects.
839
840 template<int size, bool big_endian>
841 uint64_t
842 Sized_pluginobj<size, big_endian>::do_section_addralign(unsigned int)
843 {
844   gold_unreachable();
845   return 0;
846 }
847
848 // Return the Xindex structure to use.  Not used for plugin objects.
849
850 template<int size, bool big_endian>
851 Xindex*
852 Sized_pluginobj<size, big_endian>::do_initialize_xindex()
853 {
854   gold_unreachable();
855   return NULL;
856 }
857
858 // Get symbol counts.  Not used for plugin objects.
859
860 template<int size, bool big_endian>
861 void
862 Sized_pluginobj<size, big_endian>::do_get_global_symbol_counts(const Symbol_table*,
863                                                    size_t*, size_t*) const
864 {
865   gold_unreachable();
866 }
867
868 // Get symbols.  Not used for plugin objects.
869
870 template<int size, bool big_endian>
871 const Object::Symbols*
872 Sized_pluginobj<size, big_endian>::do_get_global_symbols() const
873 {
874   gold_unreachable();
875 }
876
877 // Class Plugin_finish.  This task runs after all replacement files have
878 // been added.  For now, it's a placeholder for a possible plugin API
879 // to allow the plugin to release most of its resources.  The cleanup
880 // handlers must be called later, because they can remove the temporary
881 // object files that are needed until the end of the link.
882
883 class Plugin_finish : public Task
884 {
885  public:
886   Plugin_finish(Task_token* this_blocker, Task_token* next_blocker)
887     : this_blocker_(this_blocker), next_blocker_(next_blocker)
888   { }
889
890   ~Plugin_finish()
891   {
892     if (this->this_blocker_ != NULL)
893       delete this->this_blocker_;
894   }
895
896   Task_token*
897   is_runnable()
898   {
899     if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
900       return this->this_blocker_;
901     return NULL;
902   }
903
904   void
905   locks(Task_locker* tl)
906   { tl->add(this, this->next_blocker_); }
907
908   void
909   run(Workqueue*)
910   {
911     // We could call early cleanup handlers here.
912   }
913
914   std::string
915   get_name() const
916   { return "Plugin_finish"; }
917
918  private:
919   Task_token* this_blocker_;
920   Task_token* next_blocker_;
921 };
922
923 // Class Plugin_hook.
924
925 Plugin_hook::~Plugin_hook()
926 {
927 }
928
929 // Return whether a Plugin_hook task is runnable.
930
931 Task_token*
932 Plugin_hook::is_runnable()
933 {
934   if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
935     return this->this_blocker_;
936   return NULL;
937 }
938
939 // Return a Task_locker for a Plugin_hook task.  We don't need any
940 // locks here.
941
942 void
943 Plugin_hook::locks(Task_locker*)
944 {
945 }
946
947 // Run the "all symbols read" plugin hook.
948
949 void
950 Plugin_hook::run(Workqueue* workqueue)
951 {
952   gold_assert(this->options_.has_plugins());
953   Symbol* start_sym;
954   if (parameters->options().entry())
955     start_sym = this->symtab_->lookup(parameters->options().entry());
956   else
957     start_sym = this->symtab_->lookup("_start");
958   if (start_sym != NULL)
959     start_sym->set_in_real_elf();
960
961   this->options_.plugins()->all_symbols_read(workqueue,
962                                              this,
963                                              this->input_objects_,
964                                              this->symtab_,
965                                              this->layout_,
966                                              this->dirpath_,
967                                              this->mapfile_,
968                                              &this->this_blocker_);
969   workqueue->queue_soon(new Plugin_finish(this->this_blocker_,
970                                           this->next_blocker_));
971 }
972
973 // The C interface routines called by the plugins.
974
975 #ifdef ENABLE_PLUGINS
976
977 // Register a claim-file handler.
978
979 static enum ld_plugin_status
980 register_claim_file(ld_plugin_claim_file_handler handler)
981 {
982   gold_assert(parameters->options().has_plugins());
983   parameters->options().plugins()->set_claim_file_handler(handler);
984   return LDPS_OK;
985 }
986
987 // Register an all-symbols-read handler.
988
989 static enum ld_plugin_status
990 register_all_symbols_read(ld_plugin_all_symbols_read_handler handler)
991 {
992   gold_assert(parameters->options().has_plugins());
993   parameters->options().plugins()->set_all_symbols_read_handler(handler);
994   return LDPS_OK;
995 }
996
997 // Register a cleanup handler.
998
999 static enum ld_plugin_status
1000 register_cleanup(ld_plugin_cleanup_handler handler)
1001 {
1002   gold_assert(parameters->options().has_plugins());
1003   parameters->options().plugins()->set_cleanup_handler(handler);
1004   return LDPS_OK;
1005 }
1006
1007 // Add symbols from a plugin-claimed input file.
1008
1009 static enum ld_plugin_status
1010 add_symbols(void* handle, int nsyms, const ld_plugin_symbol* syms)
1011 {
1012   gold_assert(parameters->options().has_plugins());
1013   Pluginobj* obj = parameters->options().plugins()->make_plugin_object(
1014       static_cast<unsigned int>(reinterpret_cast<intptr_t>(handle)));
1015   if (obj == NULL)
1016     return LDPS_ERR;
1017   obj->store_incoming_symbols(nsyms, syms);
1018   return LDPS_OK;
1019 }
1020
1021 // Get the input file information with an open (possibly re-opened)
1022 // file descriptor.
1023
1024 static enum ld_plugin_status
1025 get_input_file(const void* handle, struct ld_plugin_input_file* file)
1026 {
1027   gold_assert(parameters->options().has_plugins());
1028   unsigned int obj_index =
1029       static_cast<unsigned int>(reinterpret_cast<intptr_t>(handle));
1030   return parameters->options().plugins()->get_input_file(obj_index, file);
1031 }
1032
1033 // Release the input file.
1034
1035 static enum ld_plugin_status
1036 release_input_file(const void* handle)
1037 {
1038   gold_assert(parameters->options().has_plugins());
1039   unsigned int obj_index =
1040       static_cast<unsigned int>(reinterpret_cast<intptr_t>(handle));
1041   return parameters->options().plugins()->release_input_file(obj_index);
1042 }
1043
1044 // Get the symbol resolution info for a plugin-claimed input file.
1045
1046 static enum ld_plugin_status
1047 get_symbols(const void* handle, int nsyms, ld_plugin_symbol* syms)
1048 {
1049   gold_assert(parameters->options().has_plugins());
1050   Pluginobj* obj = parameters->options().plugins()->object(
1051       static_cast<unsigned int>(reinterpret_cast<intptr_t>(handle)));
1052   if (obj == NULL)
1053     return LDPS_ERR;
1054   return obj->get_symbol_resolution_info(nsyms, syms);
1055 }
1056
1057 // Add a new (real) input file generated by a plugin.
1058
1059 static enum ld_plugin_status
1060 add_input_file(const char* pathname)
1061 {
1062   gold_assert(parameters->options().has_plugins());
1063   return parameters->options().plugins()->add_input_file(pathname, false);
1064 }
1065
1066 // Add a new (real) library required by a plugin.
1067
1068 static enum ld_plugin_status
1069 add_input_library(const char* pathname)
1070 {
1071   gold_assert(parameters->options().has_plugins());
1072   return parameters->options().plugins()->add_input_file(pathname, true);
1073 }
1074
1075 // Set the extra library path to be used by libraries added via
1076 // add_input_library
1077
1078 static enum ld_plugin_status
1079 set_extra_library_path(const char* path)
1080 {
1081   gold_assert(parameters->options().has_plugins());
1082   return parameters->options().plugins()->set_extra_library_path(path);
1083 }
1084
1085 // Issue a diagnostic message from a plugin.
1086
1087 static enum ld_plugin_status
1088 message(int level, const char* format, ...)
1089 {
1090   va_list args;
1091   va_start(args, format);
1092
1093   switch (level)
1094     {
1095     case LDPL_INFO:
1096       parameters->errors()->info(format, args);
1097       break;
1098     case LDPL_WARNING:
1099       parameters->errors()->warning(format, args);
1100       break;
1101     case LDPL_ERROR:
1102     default:
1103       parameters->errors()->error(format, args);
1104       break;
1105     case LDPL_FATAL:
1106       parameters->errors()->fatal(format, args);
1107       break;
1108     }
1109
1110   va_end(args);
1111   return LDPS_OK;
1112 }
1113
1114 #endif // ENABLE_PLUGINS
1115
1116 // Allocate a Pluginobj object of the appropriate size and endianness.
1117
1118 static Pluginobj*
1119 make_sized_plugin_object(Input_file* input_file, off_t offset, off_t filesize)
1120 {
1121   Pluginobj* obj = NULL;
1122
1123   parameters_force_valid_target();
1124   const Target& target(parameters->target());
1125
1126   if (target.get_size() == 32)
1127     {
1128       if (target.is_big_endian())
1129 #ifdef HAVE_TARGET_32_BIG
1130         obj = new Sized_pluginobj<32, true>(input_file->filename(),
1131                                             input_file, offset, filesize);
1132 #else
1133         gold_error(_("%s: not configured to support "
1134                      "32-bit big-endian object"),
1135                    input_file->filename().c_str());
1136 #endif
1137       else
1138 #ifdef HAVE_TARGET_32_LITTLE
1139         obj = new Sized_pluginobj<32, false>(input_file->filename(),
1140                                              input_file, offset, filesize);
1141 #else
1142         gold_error(_("%s: not configured to support "
1143                      "32-bit little-endian object"),
1144                    input_file->filename().c_str());
1145 #endif
1146     }
1147   else if (target.get_size() == 64)
1148     {
1149       if (target.is_big_endian())
1150 #ifdef HAVE_TARGET_64_BIG
1151         obj = new Sized_pluginobj<64, true>(input_file->filename(),
1152                                             input_file, offset, filesize);
1153 #else
1154         gold_error(_("%s: not configured to support "
1155                      "64-bit big-endian object"),
1156                    input_file->filename().c_str());
1157 #endif
1158       else
1159 #ifdef HAVE_TARGET_64_LITTLE
1160         obj = new Sized_pluginobj<64, false>(input_file->filename(),
1161                                              input_file, offset, filesize);
1162 #else
1163         gold_error(_("%s: not configured to support "
1164                      "64-bit little-endian object"),
1165                    input_file->filename().c_str());
1166 #endif
1167     }
1168
1169   gold_assert(obj != NULL);
1170   return obj;
1171 }
1172
1173 } // End namespace gold.