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 surrounded 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)