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 section_size_type armap_size
=
88 convert_to_section_size_type(this->read_header(sarmag
, &armap_name
));
90 if (armap_name
.empty())
92 this->read_armap(sarmag
+ sizeof(Archive_header
), armap_size
);
93 off
= sarmag
+ sizeof(Archive_header
) + armap_size
;
95 else if (!this->input_file_
->options().include_whole_archive())
96 gold_error(_("%s: no archive symbol table (run ranlib)"),
97 this->name().c_str());
99 // See if there is an extended name table.
103 off_t extended_size
= this->read_header(off
, &xname
);
106 const unsigned char* p
= this->get_view(off
+ sizeof(Archive_header
),
107 extended_size
, false);
108 const char* px
= reinterpret_cast<const char*>(p
);
109 this->extended_names_
.assign(px
, extended_size
);
112 // Opening the file locked it. Unlock it now.
113 this->input_file_
->file().unlock(task
);
116 // Read the archive symbol map.
119 Archive::read_armap(off_t start
, section_size_type size
)
121 // Read in the entire armap.
122 const unsigned char* p
= this->get_view(start
, size
, false);
124 // Numbers in the armap are always big-endian.
125 const elfcpp::Elf_Word
* pword
= reinterpret_cast<const elfcpp::Elf_Word
*>(p
);
126 unsigned int nsyms
= elfcpp::Swap
<32, true>::readval(pword
);
129 // Note that the addition is in units of sizeof(elfcpp::Elf_Word).
130 const char* pnames
= reinterpret_cast<const char*>(pword
+ nsyms
);
131 section_size_type names_size
=
132 reinterpret_cast<const char*>(p
) + size
- pnames
;
133 this->armap_names_
.assign(pnames
, names_size
);
135 this->armap_
.resize(nsyms
);
137 section_offset_type name_offset
= 0;
138 for (unsigned int i
= 0; i
< nsyms
; ++i
)
140 this->armap_
[i
].name_offset
= name_offset
;
141 this->armap_
[i
].file_offset
= elfcpp::Swap
<32, true>::readval(pword
);
142 name_offset
+= strlen(pnames
+ name_offset
) + 1;
146 if (static_cast<section_size_type
>(name_offset
) > names_size
)
147 gold_error(_("%s: bad archive symbol table names"),
148 this->name().c_str());
150 // This array keeps track of which symbols are for archive elements
151 // which we have already included in the link.
152 this->armap_checked_
.resize(nsyms
);
155 // Read the header of an archive member at OFF. Fail if something
156 // goes wrong. Return the size of the member. Set *PNAME to the name
160 Archive::read_header(off_t off
, std::string
* pname
)
162 const unsigned char* p
= this->get_view(off
, sizeof(Archive_header
), false);
163 const Archive_header
* hdr
= reinterpret_cast<const Archive_header
*>(p
);
164 return this->interpret_header(hdr
, off
, pname
);
167 // Interpret the header of HDR, the header of the archive member at
168 // file offset OFF. Fail if something goes wrong. Return the size of
169 // the member. Set *PNAME to the name of the member.
172 Archive::interpret_header(const Archive_header
* hdr
, off_t off
,
175 if (memcmp(hdr
->ar_fmag
, arfmag
, sizeof arfmag
) != 0)
177 gold_error(_("%s: malformed archive header at %zu"),
178 this->name().c_str(), static_cast<size_t>(off
));
179 return this->input_file_
->file().filesize() - 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 gold_error(_("%s: malformed archive header size at %zu"),
198 this->name().c_str(), static_cast<size_t>(off
));
199 return this->input_file_
->file().filesize() - off
;
202 if (hdr
->ar_name
[0] != '/')
204 const char* name_end
= strchr(hdr
->ar_name
, '/');
206 || name_end
- hdr
->ar_name
>= static_cast<int>(sizeof hdr
->ar_name
))
208 gold_error(_("%s: malformed archive header name at %zu"),
209 this->name().c_str(), static_cast<size_t>(off
));
210 return this->input_file_
->file().filesize() - off
;
212 pname
->assign(hdr
->ar_name
, name_end
- hdr
->ar_name
);
214 else if (hdr
->ar_name
[1] == ' ')
216 // This is the symbol table.
219 else if (hdr
->ar_name
[1] == '/')
221 // This is the extended name table.
222 pname
->assign(1, '/');
227 long x
= strtol(hdr
->ar_name
+ 1, &end
, 10);
230 || (x
== LONG_MAX
&& errno
== ERANGE
)
231 || static_cast<size_t>(x
) >= this->extended_names_
.size())
233 gold_error(_("%s: bad extended name index at %zu"),
234 this->name().c_str(), static_cast<size_t>(off
));
235 return this->input_file_
->file().filesize() - off
;
238 const char* name
= this->extended_names_
.data() + x
;
239 const char* name_end
= strchr(name
, '/');
240 if (static_cast<size_t>(name_end
- name
) > this->extended_names_
.size()
241 || name_end
[1] != '\n')
243 gold_error(_("%s: bad extended name entry at header %zu"),
244 this->name().c_str(), static_cast<size_t>(off
));
245 return this->input_file_
->file().filesize() - off
;
247 pname
->assign(name
, name_end
- name
);
253 // Select members from the archive and add them to the link. We walk
254 // through the elements in the archive map, and look each one up in
255 // the symbol table. If it exists as a strong undefined symbol, we
256 // pull in the corresponding element. We have to do this in a loop,
257 // since pulling in one element may create new undefined symbols which
258 // may be satisfied by other objects in the archive.
261 Archive::add_symbols(Symbol_table
* symtab
, Layout
* layout
,
262 Input_objects
* input_objects
)
264 if (this->input_file_
->options().include_whole_archive())
265 return this->include_all_members(symtab
, layout
, input_objects
);
267 const size_t armap_size
= this->armap_
.size();
269 // This is a quick optimization, since we usually see many symbols
270 // in a row with the same offset. last_seen_offset holds the last
271 // offset we saw that was present in the seen_offsets_ set.
272 off_t last_seen_offset
= -1;
274 // Track which symbols in the symbol table we've already found to be
277 bool added_new_object
;
280 added_new_object
= false;
281 for (size_t i
= 0; i
< armap_size
; ++i
)
283 if (this->armap_checked_
[i
])
285 if (this->armap_
[i
].file_offset
== last_seen_offset
)
287 this->armap_checked_
[i
] = true;
290 if (this->seen_offsets_
.find(this->armap_
[i
].file_offset
)
291 != this->seen_offsets_
.end())
293 this->armap_checked_
[i
] = true;
294 last_seen_offset
= this->armap_
[i
].file_offset
;
298 const char* sym_name
= (this->armap_names_
.data()
299 + this->armap_
[i
].name_offset
);
300 Symbol
* sym
= symtab
->lookup(sym_name
);
303 else if (!sym
->is_undefined())
305 this->armap_checked_
[i
] = true;
308 else if (sym
->binding() == elfcpp::STB_WEAK
)
311 // We want to include this object in the link.
312 last_seen_offset
= this->armap_
[i
].file_offset
;
313 this->seen_offsets_
.insert(last_seen_offset
);
314 this->armap_checked_
[i
] = true;
315 this->include_member(symtab
, layout
, input_objects
,
317 added_new_object
= true;
320 while (added_new_object
);
323 // Include all the archive members in the link. This is for --whole-archive.
326 Archive::include_all_members(Symbol_table
* symtab
, Layout
* layout
,
327 Input_objects
* input_objects
)
330 off_t filesize
= this->input_file_
->file().filesize();
333 if (filesize
- off
< static_cast<off_t
>(sizeof(Archive_header
)))
336 gold_error(_("%s: short archive header at %zu"),
337 this->name().c_str(), static_cast<size_t>(off
));
341 unsigned char hdr_buf
[sizeof(Archive_header
)];
342 this->input_file_
->file().read(off
, sizeof(Archive_header
), hdr_buf
);
344 const Archive_header
* hdr
=
345 reinterpret_cast<const Archive_header
*>(hdr_buf
);
347 off_t size
= this->interpret_header(hdr
, off
, &name
);
352 else if (name
== "/")
354 // Extended name table.
357 this->include_member(symtab
, layout
, input_objects
, off
);
359 off
+= sizeof(Archive_header
) + size
;
365 // Include an archive member in the link. OFF is the file offset of
366 // the member header.
369 Archive::include_member(Symbol_table
* symtab
, Layout
* layout
,
370 Input_objects
* input_objects
, off_t off
)
373 this->read_header(off
, &n
);
375 const off_t memoff
= off
+ static_cast<off_t
>(sizeof(Archive_header
));
377 // Read enough of the file to pick up the entire ELF header.
378 unsigned char ehdr_buf
[elfcpp::Elf_sizes
<64>::ehdr_size
];
380 off_t filesize
= this->input_file_
->file().filesize();
381 int read_size
= elfcpp::Elf_sizes
<64>::ehdr_size
;
382 if (filesize
- memoff
< read_size
)
383 read_size
= filesize
- memoff
;
387 gold_error(_("%s: member at %zu is not an ELF object"),
388 this->name().c_str(), static_cast<size_t>(off
));
392 this->input_file_
->file().read(memoff
, read_size
, ehdr_buf
);
394 static unsigned char elfmagic
[4] =
396 elfcpp::ELFMAG0
, elfcpp::ELFMAG1
,
397 elfcpp::ELFMAG2
, elfcpp::ELFMAG3
399 if (memcmp(ehdr_buf
, elfmagic
, 4) != 0)
401 gold_error(_("%s: member at %zu is not an ELF object"),
402 this->name().c_str(), static_cast<size_t>(off
));
406 Object
* obj
= make_elf_object((std::string(this->input_file_
->filename())
408 this->input_file_
, memoff
, ehdr_buf
,
411 if (input_objects
->add_object(obj
))
413 Read_symbols_data sd
;
414 obj
->read_symbols(&sd
);
415 obj
->layout(symtab
, layout
, &sd
);
416 obj
->add_symbols(symtab
, &sd
);
420 // FIXME: We need to close the descriptor here.
426 // Add_archive_symbols methods.
428 Add_archive_symbols::~Add_archive_symbols()
430 if (this->this_blocker_
!= NULL
)
431 delete this->this_blocker_
;
432 // next_blocker_ is deleted by the task associated with the next
436 // Return whether we can add the archive symbols. We are blocked by
437 // this_blocker_. We block next_blocker_. We also lock the file.
440 Add_archive_symbols::is_runnable()
442 if (this->this_blocker_
!= NULL
&& this->this_blocker_
->is_blocked())
443 return this->this_blocker_
;
448 Add_archive_symbols::locks(Task_locker
* tl
)
450 tl
->add(this, this->next_blocker_
);
451 tl
->add(this, this->archive_
->token());
455 Add_archive_symbols::run(Workqueue
*)
457 this->archive_
->add_symbols(this->symtab_
, this->layout_
,
458 this->input_objects_
);
460 this->archive_
->release();
462 if (this->input_group_
!= NULL
)
463 this->input_group_
->add_archive(this->archive_
);
466 // We no longer need to know about this archive.
467 delete this->archive_
;
468 this->archive_
= NULL
;
472 } // End namespace gold.