1 // archive.h -- archive support for gold -*- C++ -*-
3 // Copyright 2006, 2007, 2008, 2010, 2011 Free Software Foundation, Inc.
4 // Written by Ian Lance Taylor <iant@google.com>.
6 // This file is part of gold.
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.
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.
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.
23 #ifndef GOLD_ARCHIVE_H
24 #define GOLD_ARCHIVE_H
30 #include "workqueue.h"
43 class Read_symbols_data;
45 class Incremental_archive_entry;
47 // An entry in the archive map of offsets to members.
51 : obj_(NULL), sd_(NULL)
53 Archive_member(Object* obj, Read_symbols_data* sd)
58 // The data to pass from read_symbols() to add_symbols().
59 Read_symbols_data* sd_;
62 // This class represents an archive--generally a libNAME.a file.
63 // Archives have a symbol table and a list of objects.
68 Archive(const std::string& name, Input_file* input_file,
69 bool is_thin_archive, Dirsearch* dirpath, Task* task);
71 // The length of the magic string at the start of an archive.
72 static const int sarmag = 8;
74 // The magic string at the start of an archive.
75 static const char armag[sarmag];
76 static const char armagt[sarmag];
78 // The string expected at the end of an archive member header.
79 static const char arfmag[2];
81 // The name of the object. This is the name used on the command
82 // line; e.g., if "-lgcc" is on the command line, this will be
86 { return this->name_; }
91 { return this->input_file_; }
96 { return this->input_file_->filename(); }
98 // Set up the archive: read the symbol map.
102 // Get a reference to the underlying file.
105 { return this->input_file_->file(); }
109 { return this->input_file_->file(); }
111 // Lock the underlying file.
114 { this->input_file_->file().lock(t); }
116 // Unlock the underlying file.
118 unlock(const Task* t)
119 { this->input_file_->file().unlock(t); }
121 // Return whether the underlying file is locked.
124 { return this->input_file_->file().is_locked(); }
126 // Return the token, so that the task can be queued.
129 { return this->input_file_->file().token(); }
131 // Release the underlying file.
134 { this->input_file_->file().release(); }
136 // Clear uncached views in the underlying file.
138 clear_uncached_views()
139 { this->input_file_->file().clear_uncached_views(); }
141 // Whether this is a thin archive.
143 is_thin_archive() const
144 { return this->is_thin_archive_; }
146 // Unlock any nested archives.
148 unlock_nested_archives();
150 // Select members from the archive as needed and add them to the
153 add_symbols(Symbol_table*, Layout*, Input_objects*, Mapfile*);
155 // Return whether the archive defines the symbol.
157 defines_symbol(Symbol*) const;
159 // Dump statistical information to stderr.
163 // Return the number of members in the archive.
167 // Return the no-export flag.
170 { return this->no_export_; }
172 // Store a pointer to the incremental link info for the archive.
174 set_incremental_info(Incremental_archive_entry* info)
175 { this->incremental_info_ = info; }
177 // Return the pointer to the incremental link info for the archive.
178 Incremental_archive_entry*
179 incremental_info() const
180 { return this->incremental_info_; }
182 // When we see a symbol in an archive we might decide to include the member,
183 // not include the member or be undecided. This enum represents these
190 SHOULD_INCLUDE_UNKNOWN
193 static Should_include
194 should_include_member(Symbol_table* symtab, Layout*, const char* sym_name,
195 Symbol** symp, std::string* why, char** tmpbufp,
202 // Iterator class for unused global symbols. This iterator is used
203 // for incremental links.
205 class Unused_symbol_iterator
208 Unused_symbol_iterator(Archive* arch,
209 std::vector<Armap_entry>::const_iterator it)
210 : arch_(arch), it_(it)
211 { this->skip_used_symbols(); }
215 { return this->arch_->armap_names_.data() + this->it_->name_offset; }
217 Unused_symbol_iterator&
221 this->skip_used_symbols();
226 operator==(const Unused_symbol_iterator p) const
227 { return this->it_ == p.it_; }
230 operator!=(const Unused_symbol_iterator p) const
231 { return this->it_ != p.it_; }
234 // Skip over symbols defined by members that have been included.
238 while (this->it_ != this->arch_->armap_.end()
239 && (this->arch_->seen_offsets_.find(this->it_->file_offset)
240 != this->arch_->seen_offsets_.end()))
244 // The underlying archive.
247 // The underlying iterator over all entries in the archive map.
248 std::vector<Armap_entry>::const_iterator it_;
251 // Return an iterator referring to the first unused symbol.
252 Unused_symbol_iterator
253 unused_symbols_begin()
254 { return Unused_symbol_iterator(this, this->armap_.begin()); }
256 // Return an iterator referring to the end of the unused symbols.
257 Unused_symbol_iterator
259 { return Unused_symbol_iterator(this, this->armap_.end()); }
262 Archive(const Archive&);
263 Archive& operator=(const Archive&);
265 struct Archive_header;
267 // Total number of archives seen.
268 static unsigned int total_archives;
269 // Total number of archive members seen.
270 static unsigned int total_members;
271 // Number of archive members loaded.
272 static unsigned int total_members_loaded;
274 // Get a view into the underlying file.
276 get_view(off_t start, section_size_type size, bool aligned, bool cache)
277 { return this->input_file_->file().get_view(0, start, size, aligned, cache); }
279 // Read the archive symbol map.
281 read_armap(off_t start, section_size_type size);
283 // Read an archive member header at OFF. CACHE is whether to cache
284 // the file view. Return the size of the member, and set *PNAME to
287 read_header(off_t off, bool cache, std::string* pname, off_t* nested_off);
289 // Interpret an archive header HDR at OFF. Return the size of the
290 // member, and set *PNAME to the name.
292 interpret_header(const Archive_header* hdr, off_t off, std::string* pname,
293 off_t* nested_off) const;
295 // Get the file and offset for an archive member, which may be an
296 // external member of a thin archive. Set *INPUT_FILE to the
297 // file containing the actual member, *MEMOFF to the offset
298 // within that file (0 if not a nested archive), and *MEMBER_NAME
299 // to the name of the archive member. Return TRUE on success.
301 get_file_and_offset(off_t off, Input_file** input_file, off_t* memoff,
302 off_t* memsize, std::string* member_name);
304 // Return an ELF object for the member at offset OFF.
306 get_elf_object_for_member(off_t off, bool*);
308 // Read the symbols from all the archive members in the link.
312 // Read the symbols from an archive member in the link. OFF is the file
313 // offset of the member header.
315 read_symbols(off_t off);
317 // Include all the archive members in the link.
319 include_all_members(Symbol_table*, Layout*, Input_objects*, Mapfile*);
321 // Include an archive member in the link.
323 include_member(Symbol_table*, Layout*, Input_objects*, off_t off,
324 Mapfile*, Symbol*, const char* why);
326 // Return whether we found this archive by searching a directory.
329 { return this->input_file_->will_search_for(); }
331 // Iterate over archive members.
332 class const_iterator;
340 friend class const_iterator;
342 // An entry in the archive map of symbols to object files.
345 // The offset to the symbol name in armap_names_.
347 // The file offset to the object in the archive.
351 // A simple hash code for off_t values.
355 size_t operator()(off_t val) const
356 { return static_cast<size_t>(val); }
359 // For keeping track of open nested archives in a thin archive file.
360 typedef Unordered_map<std::string, Archive*> Nested_archive_table;
362 // Name of object as printed to user.
364 // For reading the file.
365 Input_file* input_file_;
367 std::vector<Armap_entry> armap_;
368 // The names in the archive map.
369 std::string armap_names_;
370 // The extended name table.
371 std::string extended_names_;
372 // Track which symbols in the archive map are for elements which are
373 // defined or which have already been included in the link.
374 std::vector<bool> armap_checked_;
375 // Track which elements have been included by offset.
376 Unordered_set<off_t, Seen_hash> seen_offsets_;
377 // Table of objects whose symbols have been pre-read.
378 std::map<off_t, Archive_member> members_;
379 // True if this is a thin archive.
380 const bool is_thin_archive_;
381 // True if we have included at least one object from this archive.
382 bool included_member_;
383 // Table of nested archives, indexed by filename.
384 Nested_archive_table nested_archives_;
385 // The directory search path.
387 // The task reading this archive.
389 // Number of members in this archive;
390 unsigned int num_members_;
391 // True if we exclude this library archive from automatic export.
393 // The incremental link information for this archive.
394 Incremental_archive_entry* incremental_info_;
397 // This class is used to read an archive and pick out the desired
398 // elements and add them to the link.
400 class Add_archive_symbols : public Task
403 Add_archive_symbols(Symbol_table* symtab, Layout* layout,
404 Input_objects* input_objects, Dirsearch* dirpath,
405 int dirindex, Mapfile* mapfile,
406 const Input_argument* input_argument,
407 Archive* archive, Input_group* input_group,
408 Task_token* this_blocker,
409 Task_token* next_blocker)
410 : symtab_(symtab), layout_(layout), input_objects_(input_objects),
411 dirpath_(dirpath), dirindex_(dirindex), mapfile_(mapfile),
412 input_argument_(input_argument), archive_(archive),
413 input_group_(input_group), this_blocker_(this_blocker),
414 next_blocker_(next_blocker)
417 ~Add_archive_symbols();
419 // The standard Task methods.
433 if (this->archive_ == NULL)
434 return "Add_archive_symbols";
435 return "Add_archive_symbols " + this->archive_->file().filename();
439 Symbol_table* symtab_;
441 Input_objects* input_objects_;
445 const Input_argument* input_argument_;
447 Input_group* input_group_;
448 Task_token* this_blocker_;
449 Task_token* next_blocker_;
452 // This class represents the files surrunded by a --start-lib ... --end-lib.
457 Lib_group(const Input_file_lib* lib, Task* task);
459 // Select members from the lib group as needed and add them to the link.
461 add_symbols(Symbol_table*, Layout*, Input_objects*);
463 // Include a member of the lib group in the link.
465 include_member(Symbol_table*, Layout*, Input_objects*, const Archive_member&);
470 return &this->members_[i];
473 // Dump statistical information to stderr.
477 // Total number of archives seen.
478 static unsigned int total_lib_groups;
479 // Total number of archive members seen.
480 static unsigned int total_members;
481 // Number of archive members loaded.
482 static unsigned int total_members_loaded;
485 // For reading the files.
486 const Input_file_lib* lib_;
487 // The task reading this lib group.
489 // Table of the objects in the group.
490 std::vector<Archive_member> members_;
493 // This class is used to pick out the desired elements and add them to the link.
495 class Add_lib_group_symbols : public Task
498 Add_lib_group_symbols(Symbol_table* symtab, Layout* layout,
499 Input_objects* input_objects,
500 Lib_group* lib, Task_token* next_blocker)
501 : symtab_(symtab), layout_(layout), input_objects_(input_objects),
502 lib_(lib), readsyms_blocker_(NULL), this_blocker_(NULL),
503 next_blocker_(next_blocker)
506 ~Add_lib_group_symbols();
508 // The standard Task methods.
519 // Set the blocker to use for this task.
521 set_blocker(Task_token* readsyms_blocker, Task_token* this_blocker)
523 gold_assert(this->readsyms_blocker_ == NULL && this->this_blocker_ == NULL);
524 this->readsyms_blocker_ = readsyms_blocker;
525 this->this_blocker_ = this_blocker;
531 return "Add_lib_group_symbols";
535 Symbol_table* symtab_;
537 Input_objects* input_objects_;
539 Task_token* readsyms_blocker_;
540 Task_token* this_blocker_;
541 Task_token* next_blocker_;
544 } // End namespace gold.
546 #endif // !defined(GOLD_ARCHIVE_H)