1 // archive.cc -- archive support for gold
3 // Copyright 2006, 2007 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.
41 // The header of an entry in the archive. This is all readable text,
42 // padded with spaces where necesary. If the contents of an archive
43 // are all text file, the entire archive is readable.
45 struct Archive::Archive_header
49 // The file modification time.
51 // The user's UID in decimal.
53 // The user's GID in decimal.
55 // The file mode in octal.
57 // The file size in decimal.
59 // The final magic code.
65 const char Archive::armag
[sarmag
] =
67 '!', '<', 'a', 'r', 'c', 'h', '>', '\n'
70 const char Archive::arfmag
[2] = { '`', '\n' };
72 // Set up the archive: read the symbol map and the extended name
78 // The first member of the archive should be the symbol table.
79 std::string armap_name
;
80 off_t armap_size
= this->read_header(sarmag
, &armap_name
);
82 if (armap_name
.empty())
84 this->read_armap(sarmag
+ sizeof(Archive_header
), armap_size
);
85 off
= sarmag
+ sizeof(Archive_header
) + armap_size
;
87 else if (!this->input_file_
->options().include_whole_archive())
89 fprintf(stderr
, _("%s: %s: no archive symbol table (run ranlib)\n"),
90 program_name
, this->name().c_str());
96 // See if there is an extended name table.
100 off_t extended_size
= this->read_header(off
, &xname
);
103 const unsigned char* p
= this->get_view(off
+ sizeof(Archive_header
),
104 extended_size
, false);
105 const char* px
= reinterpret_cast<const char*>(p
);
106 this->extended_names_
.assign(px
, extended_size
);
109 // Opening the file locked it. Unlock it now.
110 this->input_file_
->file().unlock();
113 // Read the archive symbol map.
116 Archive::read_armap(off_t start
, off_t size
)
118 // Read in the entire armap.
119 const unsigned char* p
= this->get_view(start
, size
, false);
121 // Numbers in the armap are always big-endian.
122 const elfcpp::Elf_Word
* pword
= reinterpret_cast<const elfcpp::Elf_Word
*>(p
);
123 unsigned int nsyms
= elfcpp::Swap
<32, true>::readval(pword
);
126 // Note that the addition is in units of sizeof(elfcpp::Elf_Word).
127 const char* pnames
= reinterpret_cast<const char*>(pword
+ nsyms
);
128 off_t names_size
= reinterpret_cast<const char*>(p
) + size
- pnames
;
129 this->armap_names_
.assign(pnames
, names_size
);
131 this->armap_
.resize(nsyms
);
133 off_t name_offset
= 0;
134 for (unsigned int i
= 0; i
< nsyms
; ++i
)
136 this->armap_
[i
].name_offset
= name_offset
;
137 this->armap_
[i
].file_offset
= elfcpp::Swap
<32, true>::readval(pword
);
138 name_offset
+= strlen(pnames
+ name_offset
) + 1;
142 if (reinterpret_cast<const unsigned char*>(pnames
) - p
> size
)
144 fprintf(stderr
, _("%s: %s: bad archive symbol table names\n"),
145 program_name
, this->name().c_str());
149 // This array keeps track of which symbols are for archive elements
150 // which we have already included in the link.
151 this->armap_checked_
.resize(nsyms
);
154 // Read the header of an archive member at OFF. Fail if something
155 // goes wrong. Return the size of the member. Set *PNAME to the name
159 Archive::read_header(off_t off
, std::string
* pname
)
161 const unsigned char* p
= this->get_view(off
, sizeof(Archive_header
), false);
162 const Archive_header
* hdr
= reinterpret_cast<const Archive_header
*>(p
);
163 return this->interpret_header(hdr
, off
, pname
);
166 // Interpret the header of HDR, the header of the archive member at
167 // file offset OFF. Fail if something goes wrong. Return the size of
168 // the member. Set *PNAME to the name of the member.
171 Archive::interpret_header(const Archive_header
* hdr
, off_t off
,
174 if (memcmp(hdr
->ar_fmag
, arfmag
, sizeof arfmag
) != 0)
176 fprintf(stderr
, _("%s; %s: malformed archive header at %ld\n"),
177 program_name
, this->name().c_str(),
178 static_cast<long>(off
));
182 const int size_string_size
= sizeof hdr
->ar_size
;
183 char size_string
[size_string_size
+ 1];
184 memcpy(size_string
, hdr
->ar_size
, size_string_size
);
185 char* ps
= size_string
+ size_string_size
;
186 while (ps
[-1] == ' ')
192 off_t member_size
= strtol(size_string
, &end
, 10);
195 || (member_size
== LONG_MAX
&& errno
== ERANGE
))
197 fprintf(stderr
, _("%s: %s: malformed archive header size at %ld\n"),
198 program_name
, this->name().c_str(),
199 static_cast<long>(off
));
203 if (hdr
->ar_name
[0] != '/')
205 const char* name_end
= strchr(hdr
->ar_name
, '/');
207 || name_end
- hdr
->ar_name
>= static_cast<int>(sizeof hdr
->ar_name
))
209 fprintf(stderr
, _("%s: %s: malformed archive header name at %ld\n"),
210 program_name
, this->name().c_str(),
211 static_cast<long>(off
));
214 pname
->assign(hdr
->ar_name
, name_end
- hdr
->ar_name
);
216 else if (hdr
->ar_name
[1] == ' ')
218 // This is the symbol table.
221 else if (hdr
->ar_name
[1] == '/')
223 // This is the extended name table.
224 pname
->assign(1, '/');
229 long x
= strtol(hdr
->ar_name
+ 1, &end
, 10);
232 || (x
== LONG_MAX
&& errno
== ERANGE
)
233 || static_cast<size_t>(x
) >= this->extended_names_
.size())
235 fprintf(stderr
, _("%s: %s: bad extended name index at %ld\n"),
236 program_name
, this->name().c_str(),
237 static_cast<long>(off
));
241 const char* name
= this->extended_names_
.data() + x
;
242 const char* name_end
= strchr(name
, '/');
243 if (static_cast<size_t>(name_end
- name
) > this->extended_names_
.size()
244 || name_end
[1] != '\n')
246 fprintf(stderr
, _("%s: %s: bad extended name entry at header %ld\n"),
247 program_name
, this->name().c_str(),
248 static_cast<long>(off
));
251 pname
->assign(name
, name_end
- name
);
257 // Select members from the archive and add them to the link. We walk
258 // through the elements in the archive map, and look each one up in
259 // the symbol table. If it exists as a strong undefined symbol, we
260 // pull in the corresponding element. We have to do this in a loop,
261 // since pulling in one element may create new undefined symbols which
262 // may be satisfied by other objects in the archive.
265 Archive::add_symbols(Symbol_table
* symtab
, Layout
* layout
,
266 Input_objects
* input_objects
)
268 if (this->input_file_
->options().include_whole_archive())
269 return this->include_all_members(symtab
, layout
, input_objects
);
271 const size_t armap_size
= this->armap_
.size();
273 // This is a quick optimization, since we usually see many symbols
274 // in a row with the same offset. last_seen_offset holds the last
275 // offset we saw that was present in the seen_offsets_ set.
276 off_t last_seen_offset
= -1;
278 // Track which symbols in the symbol table we've already found to be
281 bool added_new_object
;
284 added_new_object
= false;
285 for (size_t i
= 0; i
< armap_size
; ++i
)
287 if (this->armap_checked_
[i
])
289 if (this->armap_
[i
].file_offset
== last_seen_offset
)
291 this->armap_checked_
[i
] = true;
294 if (this->seen_offsets_
.find(this->armap_
[i
].file_offset
)
295 != this->seen_offsets_
.end())
297 this->armap_checked_
[i
] = true;
298 last_seen_offset
= this->armap_
[i
].file_offset
;
302 const char* sym_name
= (this->armap_names_
.data()
303 + this->armap_
[i
].name_offset
);
304 Symbol
* sym
= symtab
->lookup(sym_name
);
307 else if (!sym
->is_undefined())
309 this->armap_checked_
[i
] = true;
312 else if (sym
->binding() == elfcpp::STB_WEAK
)
315 // We want to include this object in the link.
316 last_seen_offset
= this->armap_
[i
].file_offset
;
317 this->seen_offsets_
.insert(last_seen_offset
);
318 this->armap_checked_
[i
] = true;
319 this->include_member(symtab
, layout
, input_objects
,
321 added_new_object
= true;
324 while (added_new_object
);
327 // Include all the archive members in the link. This is for --whole-archive.
330 Archive::include_all_members(Symbol_table
* symtab
, Layout
* layout
,
331 Input_objects
* input_objects
)
334 off_t filesize
= this->input_file_
->file().filesize();
337 if (filesize
- off
< static_cast<off_t
>(sizeof(Archive_header
)))
341 fprintf(stderr
, _("%s: %s: short archive header at %ld\n"),
342 program_name
, this->name().c_str(),
343 static_cast<long>(off
));
350 unsigned char hdr_buf
[sizeof(Archive_header
)];
351 this->input_file_
->file().read(off
, sizeof(Archive_header
), hdr_buf
);
353 const Archive_header
* hdr
=
354 reinterpret_cast<const Archive_header
*>(hdr_buf
);
356 off_t size
= this->interpret_header(hdr
, off
, &name
);
361 else if (name
== "/")
363 // Extended name table.
366 this->include_member(symtab
, layout
, input_objects
, off
);
368 off
+= sizeof(Archive_header
) + size
;
374 // Include an archive member in the link. OFF is the file offset of
375 // the member header.
378 Archive::include_member(Symbol_table
* symtab
, Layout
* layout
,
379 Input_objects
* input_objects
, off_t off
)
382 this->read_header(off
, &n
);
384 const off_t memoff
= off
+ static_cast<off_t
>(sizeof(Archive_header
));
386 // Read enough of the file to pick up the entire ELF header.
387 unsigned char ehdr_buf
[elfcpp::Elf_sizes
<64>::ehdr_size
];
389 off_t filesize
= this->input_file_
->file().filesize();
390 int read_size
= elfcpp::Elf_sizes
<64>::ehdr_size
;
391 if (filesize
- memoff
< read_size
)
392 read_size
= filesize
- memoff
;
396 fprintf(stderr
, _("%s: %s: member at %ld is not an ELF object"),
397 program_name
, this->name().c_str(),
398 static_cast<long>(off
));
402 this->input_file_
->file().read(memoff
, read_size
, ehdr_buf
);
404 static unsigned char elfmagic
[4] =
406 elfcpp::ELFMAG0
, elfcpp::ELFMAG1
,
407 elfcpp::ELFMAG2
, elfcpp::ELFMAG3
409 if (memcmp(ehdr_buf
, elfmagic
, 4) != 0)
411 fprintf(stderr
, _("%s: %s: member at %ld is not an ELF object"),
412 program_name
, this->name().c_str(),
413 static_cast<long>(off
));
417 Object
* obj
= make_elf_object((std::string(this->input_file_
->filename())
419 this->input_file_
, memoff
, ehdr_buf
,
422 input_objects
->add_object(obj
);
424 Read_symbols_data sd
;
425 obj
->read_symbols(&sd
);
426 obj
->layout(symtab
, layout
, &sd
);
427 obj
->add_symbols(symtab
, &sd
);
430 // Add_archive_symbols methods.
432 Add_archive_symbols::~Add_archive_symbols()
434 if (this->this_blocker_
!= NULL
)
435 delete this->this_blocker_
;
436 // next_blocker_ is deleted by the task associated with the next
440 // Return whether we can add the archive symbols. We are blocked by
441 // this_blocker_. We block next_blocker_. We also lock the file.
443 Task::Is_runnable_type
444 Add_archive_symbols::is_runnable(Workqueue
*)
446 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
451 class Add_archive_symbols::Add_archive_symbols_locker
: public Task_locker
454 Add_archive_symbols_locker(Task_token
& token
, Workqueue
* workqueue
,
456 : blocker_(token
, workqueue
), filelock_(file
)
460 Task_locker_block blocker_
;
461 Task_locker_obj
<File_read
> filelock_
;
465 Add_archive_symbols::locks(Workqueue
* workqueue
)
467 return new Add_archive_symbols_locker(*this->next_blocker_
,
469 this->archive_
->file());
473 Add_archive_symbols::run(Workqueue
*)
475 this->archive_
->add_symbols(this->symtab_
, this->layout_
,
476 this->input_objects_
);
478 if (this->input_group_
!= NULL
)
479 this->input_group_
->add_archive(this->archive_
);
482 // We no longer need to know about this archive.
483 delete this->archive_
;
487 } // End namespace gold.