aboutsummaryrefslogtreecommitdiff
path: root/gold/plugin.h
blob: 2ee0b5e80228f8936e67f8a6694ee7da656b604f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
// plugin.h -- plugin manager for gold      -*- C++ -*-

// Copyright 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
// Written by Cary Coutant <ccoutant@google.com>.

// This file is part of gold.

// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
// MA 02110-1301, USA.

#ifndef GOLD_PLUGIN_H
#define GOLD_PLUGIN_H

#include <list>
#include <string>

#include "object.h"
#include "plugin-api.h"
#include "workqueue.h"

namespace gold
{

class General_options;
class Input_file;
class Input_objects;
class Archive;
class Input_group;
class Symbol;
class Symbol_table;
class Layout;
class Dirsearch;
class Mapfile;
class Task;
class Task_token;
class Pluginobj;
class Plugin_rescan;

// This class represents a single plugin library.

class Plugin
{
 public:
  Plugin(const char* filename)
    : handle_(NULL),
      filename_(filename),
      args_(),
      claim_file_handler_(NULL),
      all_symbols_read_handler_(NULL),
      cleanup_handler_(NULL),
      cleanup_done_(false)
  { }

  ~Plugin()
  { }

  // Load the library and call its entry point.
  void
  load();

  // Call the claim-file handler.
  bool
  claim_file(struct ld_plugin_input_file* plugin_input_file);

  // Call the all-symbols-read handler.
  void
  all_symbols_read();

  // Call the cleanup handler.
  void
  cleanup();

  // Register a claim-file handler.
  void
  set_claim_file_handler(ld_plugin_claim_file_handler handler)
  { this->claim_file_handler_ = handler; }

  // Register an all-symbols-read handler.
  void
  set_all_symbols_read_handler(ld_plugin_all_symbols_read_handler handler)
  { this->all_symbols_read_handler_ = handler; }

  // Register a claim-file handler.
  void
  set_cleanup_handler(ld_plugin_cleanup_handler handler)
  { this->cleanup_handler_ = handler; }

  // Add an argument
  void
  add_option(const char* arg)
  {
    this->args_.push_back(arg);
  }

 private:
  Plugin(const Plugin&);
  Plugin& operator=(const Plugin&);

  // The shared library handle returned by dlopen.
  void* handle_;
  // The argument string given to --plugin.
  std::string filename_;
  // The list of argument string given to --plugin-opt.
  std::vector<std::string> args_;
  // The plugin's event handlers.
  ld_plugin_claim_file_handler claim_file_handler_;
  ld_plugin_all_symbols_read_handler all_symbols_read_handler_;
  ld_plugin_cleanup_handler cleanup_handler_;
  // TRUE if the cleanup handlers have been called.
  bool cleanup_done_;
};

// A manager class for plugins.

class Plugin_manager
{
 public:
  Plugin_manager(const General_options& options)
    : plugins_(), objects_(), deferred_layout_objects_(), input_file_(NULL),
      plugin_input_file_(), rescannable_(), undefined_symbols_(),
      any_claimed_(false), in_replacement_phase_(false), any_added_(false),
      options_(options), workqueue_(NULL), task_(NULL), input_objects_(NULL),
      symtab_(NULL), layout_(NULL), dirpath_(NULL), mapfile_(NULL),
      this_blocker_(NULL), extra_search_path_()
  { this->current_ = plugins_.end(); }

  ~Plugin_manager();

  // Add a plugin library.
  void
  add_plugin(const char* filename)
  { this->plugins_.push_back(new Plugin(filename)); }

  // Add an argument to the current plugin.
  void
  add_plugin_option(const char* opt)
  {
    Plugin* last = this->plugins_.back();
    last->add_option(opt);
  }

  // Load all plugin libraries.
  void
  load_plugins();

  // Call the plugin claim-file handlers in turn to see if any claim the file.
  Pluginobj*
  claim_file(Input_file* input_file, off_t offset, off_t filesize);

  // Let the plugin manager save an archive for later rescanning.
  // This takes ownership of the Archive pointer.
  void
  save_archive(Archive*);

  // Let the plugin manager save an input group for later rescanning.
  // This takes ownership of the Input_group pointer.
  void
  save_input_group(Input_group*);

  // Call the all-symbols-read handlers.
  void
  all_symbols_read(Workqueue* workqueue, Task* task,
                   Input_objects* input_objects, Symbol_table* symtab,
                   Layout* layout, Dirsearch* dirpath, Mapfile* mapfile,
                   Task_token** last_blocker);

  // Tell the plugin manager that we've a new undefined symbol which
  // may require rescanning.
  void
  new_undefined_symbol(Symbol*);

  // Run deferred layout.
  void
  layout_deferred_objects();

  // Call the cleanup handlers.
  void
  cleanup();

  // Register a claim-file handler.
  void
  set_claim_file_handler(ld_plugin_claim_file_handler handler)
  {
    gold_assert(this->current_ != plugins_.end());
    (*this->current_)->set_claim_file_handler(handler);
  }

  // Register an all-symbols-read handler.
  void
  set_all_symbols_read_handler(ld_plugin_all_symbols_read_handler handler)
  {
    gold_assert(this->current_ != plugins_.end());
    (*this->current_)->set_all_symbols_read_handler(handler);
  }

  // Register a claim-file handler.
  void
  set_cleanup_handler(ld_plugin_cleanup_handler handler)
  {
    gold_assert(this->current_ != plugins_.end());
    (*this->current_)->set_cleanup_handler(handler);
  }

  // Make a new Pluginobj object.  This is called when the plugin calls
  // the add_symbols API.
  Pluginobj*
  make_plugin_object(unsigned int handle);

  // Return the Pluginobj associated with the given HANDLE.
  Pluginobj*
  object(unsigned int handle) const
  {
    if (handle >= this->objects_.size())
      return NULL;
    return this->objects_[handle];
  }

  // Return TRUE if any input files have been claimed by a plugin
  // and we are still in the initial input phase.
  bool
  should_defer_layout() const
  { return !this->objects_.empty() && !this->in_replacement_phase_; }

  // Add a regular object to the deferred layout list.  These are
  // objects whose layout has been deferred until after the
  // replacement files have arrived.
  void
  add_deferred_layout_object(Relobj* obj)
  { this->deferred_layout_objects_.push_back(obj); }

  // Get input file information with an open (possibly re-opened)
  // file descriptor.
  ld_plugin_status
  get_input_file(unsigned int handle, struct ld_plugin_input_file* file);

  ld_plugin_status
  get_view(unsigned int handle, const void **viewp);

  // Release an input file.
  ld_plugin_status
  release_input_file(unsigned int handle);

  // Add a new input file.
  ld_plugin_status
  add_input_file(const char* pathname, bool is_lib);

  // Set the extra library path.
  ld_plugin_status
  set_extra_library_path(const char* path);

  // Return TRUE if we are in the replacement phase.
  bool
  in_replacement_phase() const
  { return this->in_replacement_phase_; }

 private:
  Plugin_manager(const Plugin_manager&);
  Plugin_manager& operator=(const Plugin_manager&);

  // Plugin_rescan is a Task which calls the private rescan method.
  friend class Plugin_rescan;

  // An archive or input group which may have to be rescanned if a
  // plugin adds a new file.
  struct Rescannable
  {
    bool is_archive;
    union
    {
      Archive* archive;
      Input_group* input_group;
    } u;

    Rescannable(Archive* archive)
      : is_archive(true)
    { this->u.archive = archive; }

    Rescannable(Input_group* input_group)
      : is_archive(false)
    { this->u.input_group = input_group; }
  };

  typedef std::list<Plugin*> Plugin_list;
  typedef std::vector<Pluginobj*> Object_list;
  typedef std::vector<Relobj*> Deferred_layout_list;
  typedef std::vector<Rescannable> Rescannable_list;
  typedef std::vector<Symbol*> Undefined_symbol_list;

  // Rescan archives for undefined symbols.
  void
  rescan(Task*);

  // See whether the rescannable at index I defines SYM.
  bool
  rescannable_defines(size_t i, Symbol* sym);

  // The list of plugin libraries.
  Plugin_list plugins_;
  // A pointer to the current plugin.  Used while loading plugins.
  Plugin_list::iterator current_;

  // The list of plugin objects.  The index of an item in this list
  // serves as the "handle" that we pass to the plugins.
  Object_list objects_;

  // The list of regular objects whose layout has been deferred.
  Deferred_layout_list deferred_layout_objects_;

  // The file currently up for claim by the plugins.
  Input_file* input_file_;
  struct ld_plugin_input_file plugin_input_file_;

  // A list of archives and input groups being saved for possible
  // later rescanning.
  Rescannable_list rescannable_;

  // A list of undefined symbols found in added files.
  Undefined_symbol_list undefined_symbols_;

  // Whether any input files have been claimed by a plugin.
  bool any_claimed_;

  // Set to true after the all symbols read event; indicates that we
  // are processing replacement files whose symbols should replace the
  // placeholder symbols from the Pluginobj objects.
  bool in_replacement_phase_;

  // Whether any input files or libraries were added by a plugin.
  bool any_added_;

  const General_options& options_;
  Workqueue* workqueue_;
  Task* task_;
  Input_objects* input_objects_;
  Symbol_table* symtab_;
  Layout* layout_;
  Dirsearch* dirpath_;
  Mapfile* mapfile_;
  Task_token* this_blocker_;

  // An extra directory to seach for the libraries passed by
  // add_input_library.
  std::string extra_search_path_;
};


// An object file claimed by a plugin.  This is an abstract base class.
// The implementation is the template class Sized_pluginobj.

class Pluginobj : public Object
{
 public:

  typedef std::vector<Symbol*> Symbols;

  Pluginobj(const std::string& name, Input_file* input_file, off_t offset,
            off_t filesize);

  // Fill in the symbol resolution status for the given plugin symbols.
  ld_plugin_status
  get_symbol_resolution_info(int nsyms, ld_plugin_symbol* syms) const;

  // Store the incoming symbols from the plugin for later processing.
  void
  store_incoming_symbols(int nsyms, const struct ld_plugin_symbol* syms)
  {
    this->nsyms_ = nsyms;
    this->syms_ = syms;
  }

  // Return TRUE if the comdat group with key COMDAT_KEY from this object
  // should be kept.
  bool
  include_comdat_group(std::string comdat_key, Layout* layout);

  // Return the filename.
  const std::string&
  filename() const
  { return this->input_file()->filename(); }

  // Return the file descriptor.
  int
  descriptor()
  { return this->input_file()->file().descriptor(); }

  // Return the size of the file or archive member.
  off_t
  filesize()
  { return this->filesize_; }

 protected:
  // Return TRUE if this is an object claimed by a plugin.
  virtual Pluginobj*
  do_pluginobj()
  { return this; }

  // The number of symbols provided by the plugin.
  int nsyms_;
  
  // The symbols provided by the plugin.
  const struct ld_plugin_symbol* syms_;

  // The entries in the symbol table for the external symbols.
  Symbols symbols_;

 private:
  // Size of the file (or archive member).
  off_t filesize_;
  // Map a comdat key symbol to a boolean indicating whether the comdat
  // group in this object with that key should be kept.
  typedef Unordered_map<std::string, bool> Comdat_map;
  Comdat_map comdat_map_;
};

// A plugin object, size-specific version.

template<int size, bool big_endian>
class Sized_pluginobj : public Pluginobj
{
 public:
  Sized_pluginobj(const std::string& name, Input_file* input_file,
                  off_t offset, off_t filesize);

  // Read the symbols.
  void
  do_read_symbols(Read_symbols_data*);

  // Lay out the input sections.
  void
  do_layout(Symbol_table*, Layout*, Read_symbols_data*);

  // Add the symbols to the symbol table.
  void
  do_add_symbols(Symbol_table*, Read_symbols_data*, Layout*);

  Archive::Should_include
  do_should_include_member(Symbol_table* symtab, Layout*, Read_symbols_data*,
                           std::string* why);

  // Iterate over global symbols, calling a visitor class V for each.
  void
  do_for_all_global_symbols(Read_symbols_data* sd,
			    Library_base::Symbol_visitor_base* v);

  // Iterate over local symbols, calling a visitor class V for each GOT offset
  // associated with a local symbol.
  void
  do_for_all_local_got_entries(Got_offset_list::Visitor* v) const;

  // Get the size of a section.
  uint64_t
  do_section_size(unsigned int shndx);

  // Get the name of a section.
  std::string
  do_section_name(unsigned int shndx);

  // Return a view of the contents of a section.
  Object::Location
  do_section_contents(unsigned int shndx);

  // Return section flags.
  uint64_t
  do_section_flags(unsigned int shndx);

  // Return section entsize.
  uint64_t
  do_section_entsize(unsigned int shndx);

  // Return section address.
  uint64_t
  do_section_address(unsigned int shndx);

  // Return section type.
  unsigned int
  do_section_type(unsigned int shndx);

  // Return the section link field.
  unsigned int
  do_section_link(unsigned int shndx);

  // Return the section link field.
  unsigned int
  do_section_info(unsigned int shndx);

  // Return the section alignment.
  uint64_t
  do_section_addralign(unsigned int shndx);

  // Return the Xindex structure to use.
  Xindex*
  do_initialize_xindex();

  // Get symbol counts.
  void
  do_get_global_symbol_counts(const Symbol_table*, size_t*, size_t*) const;

  // Get global symbols.
  const Symbols*
  do_get_global_symbols() const;

  // Add placeholder symbols from a claimed file.
  ld_plugin_status
  add_symbols_from_plugin(int nsyms, const ld_plugin_symbol* syms);

 protected:

 private:
};

// This Task handles handles the "all symbols read" event hook.
// The plugin may add additional input files at this time, which must
// be queued for reading.

class Plugin_hook : public Task
{
 public:
  Plugin_hook(const General_options& options, Input_objects* input_objects,
	      Symbol_table* symtab, Layout* layout, Dirsearch* dirpath,
	      Mapfile* mapfile, Task_token* this_blocker,
	      Task_token* next_blocker)
    : options_(options), input_objects_(input_objects), symtab_(symtab),
      layout_(layout), dirpath_(dirpath), mapfile_(mapfile),
      this_blocker_(this_blocker), next_blocker_(next_blocker)
  { }

  ~Plugin_hook();

  // The standard Task methods.

  Task_token*
  is_runnable();

  void
  locks(Task_locker*);

  void
  run(Workqueue*);

  std::string
  get_name() const
  { return "Plugin_hook"; }

 private:
  const General_options& options_;
  Input_objects* input_objects_;
  Symbol_table* symtab_;
  Layout* layout_;
  Dirsearch* dirpath_;
  Mapfile* mapfile_;
  Task_token* this_blocker_;
  Task_token* next_blocker_;
};

} // End namespace gold.

#endif // !defined(GOLD_PLUGIN_H)