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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
76 Archive::setup(Task
* task
)
78 // We need to ignore empty archives.
79 if (this->input_file_
->file().filesize() == sarmag
)
81 this->input_file_
->file().unlock(task
);
85 // The first member of the archive should be the symbol table.
86 std::string armap_name
;
87 off_t armap_size
= this->read_header(sarmag
, &armap_name
);
89 if (armap_name
.empty())
91 this->read_armap(sarmag
+ sizeof(Archive_header
), armap_size
);
92 off
= sarmag
+ sizeof(Archive_header
) + armap_size
;
94 else if (!this->input_file_
->options().include_whole_archive())
95 gold_error(_("%s: no archive symbol table (run ranlib)"),
96 this->name().c_str());
98 // See if there is an extended name table.
102 off_t extended_size
= this->read_header(off
, &xname
);
105 const unsigned char* p
= this->get_view(off
+ sizeof(Archive_header
),
106 extended_size
, false);
107 const char* px
= reinterpret_cast<const char*>(p
);
108 this->extended_names_
.assign(px
, extended_size
);
111 // Opening the file locked it. Unlock it now.
112 this->input_file_
->file().unlock(task
);
115 // Read the archive symbol map.
118 Archive::read_armap(off_t start
, off_t size
)
120 // Read in the entire armap.
121 const unsigned char* p
= this->get_view(start
, size
, false);
123 // Numbers in the armap are always big-endian.
124 const elfcpp::Elf_Word
* pword
= reinterpret_cast<const elfcpp::Elf_Word
*>(p
);
125 unsigned int nsyms
= elfcpp::Swap
<32, true>::readval(pword
);
128 // Note that the addition is in units of sizeof(elfcpp::Elf_Word).
129 const char* pnames
= reinterpret_cast<const char*>(pword
+ nsyms
);
130 off_t names_size
= reinterpret_cast<const char*>(p
) + size
- pnames
;
131 this->armap_names_
.assign(pnames
, names_size
);
133 this->armap_
.resize(nsyms
);
135 off_t name_offset
= 0;
136 for (unsigned int i
= 0; i
< nsyms
; ++i
)
138 this->armap_
[i
].name_offset
= name_offset
;
139 this->armap_
[i
].file_offset
= elfcpp::Swap
<32, true>::readval(pword
);
140 name_offset
+= strlen(pnames
+ name_offset
) + 1;
144 if (reinterpret_cast<const unsigned char*>(pnames
) - p
> size
)
145 gold_error(_("%s: bad archive symbol table names"),
146 this->name().c_str());
148 // This array keeps track of which symbols are for archive elements
149 // which we have already included in the link.
150 this->armap_checked_
.resize(nsyms
);
153 // Read the header of an archive member at OFF. Fail if something
154 // goes wrong. Return the size of the member. Set *PNAME to the name
158 Archive::read_header(off_t off
, std::string
* pname
)
160 const unsigned char* p
= this->get_view(off
, sizeof(Archive_header
), false);
161 const Archive_header
* hdr
= reinterpret_cast<const Archive_header
*>(p
);
162 return this->interpret_header(hdr
, off
, pname
);
165 // Interpret the header of HDR, the header of the archive member at
166 // file offset OFF. Fail if something goes wrong. Return the size of
167 // the member. Set *PNAME to the name of the member.
170 Archive::interpret_header(const Archive_header
* hdr
, off_t off
,
173 if (memcmp(hdr
->ar_fmag
, arfmag
, sizeof arfmag
) != 0)
175 gold_error(_("%s: malformed archive header at %zu"),
176 this->name().c_str(), static_cast<size_t>(off
));
177 return this->input_file_
->file().filesize() - off
;
180 const int size_string_size
= sizeof hdr
->ar_size
;
181 char size_string
[size_string_size
+ 1];
182 memcpy(size_string
, hdr
->ar_size
, size_string_size
);
183 char* ps
= size_string
+ size_string_size
;
184 while (ps
[-1] == ' ')
190 off_t member_size
= strtol(size_string
, &end
, 10);
193 || (member_size
== LONG_MAX
&& errno
== ERANGE
))
195 gold_error(_("%s: malformed archive header size at %zu"),
196 this->name().c_str(), static_cast<size_t>(off
));
197 return this->input_file_
->file().filesize() - off
;
200 if (hdr
->ar_name
[0] != '/')
202 const char* name_end
= strchr(hdr
->ar_name
, '/');
204 || name_end
- hdr
->ar_name
>= static_cast<int>(sizeof hdr
->ar_name
))
206 gold_error(_("%s: malformed archive header name at %zu"),
207 this->name().c_str(), static_cast<size_t>(off
));
208 return this->input_file_
->file().filesize() - off
;
210 pname
->assign(hdr
->ar_name
, name_end
- hdr
->ar_name
);
212 else if (hdr
->ar_name
[1] == ' ')
214 // This is the symbol table.
217 else if (hdr
->ar_name
[1] == '/')
219 // This is the extended name table.
220 pname
->assign(1, '/');
225 long x
= strtol(hdr
->ar_name
+ 1, &end
, 10);
228 || (x
== LONG_MAX
&& errno
== ERANGE
)
229 || static_cast<size_t>(x
) >= this->extended_names_
.size())
231 gold_error(_("%s: bad extended name index at %zu"),
232 this->name().c_str(), static_cast<size_t>(off
));
233 return this->input_file_
->file().filesize() - off
;
236 const char* name
= this->extended_names_
.data() + x
;
237 const char* name_end
= strchr(name
, '/');
238 if (static_cast<size_t>(name_end
- name
) > this->extended_names_
.size()
239 || name_end
[1] != '\n')
241 gold_error(_("%s: bad extended name entry at header %zu"),
242 this->name().c_str(), static_cast<size_t>(off
));
243 return this->input_file_
->file().filesize() - off
;
245 pname
->assign(name
, name_end
- name
);
251 // Select members from the archive and add them to the link. We walk
252 // through the elements in the archive map, and look each one up in
253 // the symbol table. If it exists as a strong undefined symbol, we
254 // pull in the corresponding element. We have to do this in a loop,
255 // since pulling in one element may create new undefined symbols which
256 // may be satisfied by other objects in the archive.
259 Archive::add_symbols(Symbol_table
* symtab
, Layout
* layout
,
260 Input_objects
* input_objects
)
262 if (this->input_file_
->options().include_whole_archive())
263 return this->include_all_members(symtab
, layout
, input_objects
);
265 const size_t armap_size
= this->armap_
.size();
267 // This is a quick optimization, since we usually see many symbols
268 // in a row with the same offset. last_seen_offset holds the last
269 // offset we saw that was present in the seen_offsets_ set.
270 off_t last_seen_offset
= -1;
272 // Track which symbols in the symbol table we've already found to be
275 bool added_new_object
;
278 added_new_object
= false;
279 for (size_t i
= 0; i
< armap_size
; ++i
)
281 if (this->armap_checked_
[i
])
283 if (this->armap_
[i
].file_offset
== last_seen_offset
)
285 this->armap_checked_
[i
] = true;
288 if (this->seen_offsets_
.find(this->armap_
[i
].file_offset
)
289 != this->seen_offsets_
.end())
291 this->armap_checked_
[i
] = true;
292 last_seen_offset
= this->armap_
[i
].file_offset
;
296 const char* sym_name
= (this->armap_names_
.data()
297 + this->armap_
[i
].name_offset
);
298 Symbol
* sym
= symtab
->lookup(sym_name
);
301 else if (!sym
->is_undefined())
303 this->armap_checked_
[i
] = true;
306 else if (sym
->binding() == elfcpp::STB_WEAK
)
309 // We want to include this object in the link.
310 last_seen_offset
= this->armap_
[i
].file_offset
;
311 this->seen_offsets_
.insert(last_seen_offset
);
312 this->armap_checked_
[i
] = true;
313 this->include_member(symtab
, layout
, input_objects
,
315 added_new_object
= true;
318 while (added_new_object
);
321 // Include all the archive members in the link. This is for --whole-archive.
324 Archive::include_all_members(Symbol_table
* symtab
, Layout
* layout
,
325 Input_objects
* input_objects
)
328 off_t filesize
= this->input_file_
->file().filesize();
331 if (filesize
- off
< static_cast<off_t
>(sizeof(Archive_header
)))
334 gold_error(_("%s: short archive header at %zu"),
335 this->name().c_str(), static_cast<size_t>(off
));
339 unsigned char hdr_buf
[sizeof(Archive_header
)];
340 this->input_file_
->file().read(off
, sizeof(Archive_header
), hdr_buf
);
342 const Archive_header
* hdr
=
343 reinterpret_cast<const Archive_header
*>(hdr_buf
);
345 off_t size
= this->interpret_header(hdr
, off
, &name
);
350 else if (name
== "/")
352 // Extended name table.
355 this->include_member(symtab
, layout
, input_objects
, off
);
357 off
+= sizeof(Archive_header
) + size
;
363 // Include an archive member in the link. OFF is the file offset of
364 // the member header.
367 Archive::include_member(Symbol_table
* symtab
, Layout
* layout
,
368 Input_objects
* input_objects
, off_t off
)
371 this->read_header(off
, &n
);
373 const off_t memoff
= off
+ static_cast<off_t
>(sizeof(Archive_header
));
375 // Read enough of the file to pick up the entire ELF header.
376 unsigned char ehdr_buf
[elfcpp::Elf_sizes
<64>::ehdr_size
];
378 off_t filesize
= this->input_file_
->file().filesize();
379 int read_size
= elfcpp::Elf_sizes
<64>::ehdr_size
;
380 if (filesize
- memoff
< read_size
)
381 read_size
= filesize
- memoff
;
385 gold_error(_("%s: member at %zu is not an ELF object"),
386 this->name().c_str(), static_cast<size_t>(off
));
390 this->input_file_
->file().read(memoff
, read_size
, ehdr_buf
);
392 static unsigned char elfmagic
[4] =
394 elfcpp::ELFMAG0
, elfcpp::ELFMAG1
,
395 elfcpp::ELFMAG2
, elfcpp::ELFMAG3
397 if (memcmp(ehdr_buf
, elfmagic
, 4) != 0)
399 gold_error(_("%s: member at %zu is not an ELF object"),
400 this->name().c_str(), static_cast<size_t>(off
));
404 Object
* obj
= make_elf_object((std::string(this->input_file_
->filename())
406 this->input_file_
, memoff
, ehdr_buf
,
409 if (input_objects
->add_object(obj
))
411 Read_symbols_data sd
;
412 obj
->read_symbols(&sd
);
413 obj
->layout(symtab
, layout
, &sd
);
414 obj
->add_symbols(symtab
, &sd
);
418 // FIXME: We need to close the descriptor here.
424 // Add_archive_symbols methods.
426 Add_archive_symbols::~Add_archive_symbols()
428 if (this->this_blocker_
!= NULL
)
429 delete this->this_blocker_
;
430 // next_blocker_ is deleted by the task associated with the next
434 // Return whether we can add the archive symbols. We are blocked by
435 // this_blocker_. We block next_blocker_. We also lock the file.
438 Add_archive_symbols::is_runnable()
440 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
441 return this->this_blocker_
;
446 Add_archive_symbols::locks(Task_locker
* tl
)
448 tl
->add(this, this->next_blocker_
);
449 tl
->add(this, this->archive_
->token());
453 Add_archive_symbols::run(Workqueue
*)
455 this->archive_
->add_symbols(this->symtab_
, this->layout_
,
456 this->input_objects_
);
458 this->archive_
->release();
460 if (this->input_group_
!= NULL
)
461 this->input_group_
->add_archive(this->archive_
);
464 // We no longer need to know about this archive.
465 delete this->archive_
;
466 this->archive_
= NULL
;
470 } // End namespace gold.