2008-07-22 Simon Baldwin <simonb@google.com>
[deliverable/binutils-gdb.git] / gold / archive.cc
CommitLineData
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1// archive.cc -- archive support for gold
2
ebdbb458 3// Copyright 2006, 2007, 2008 Free Software Foundation, Inc.
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4// Written by Ian Lance Taylor <iant@google.com>.
5
6// This file is part of gold.
7
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.
12
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.
17
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.
22
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23#include "gold.h"
24
25#include <cerrno>
26#include <cstring>
27#include <climits>
28#include <vector>
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29#include "libiberty.h"
30#include "filenames.h"
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31
32#include "elfcpp.h"
7e1edb90 33#include "options.h"
7d9e3d98 34#include "mapfile.h"
61ba1cf9 35#include "fileread.h"
ead1e424 36#include "readsyms.h"
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37#include "symtab.h"
38#include "object.h"
39#include "archive.h"
40
41namespace gold
42{
43
44// The header of an entry in the archive. This is all readable text,
45// padded with spaces where necesary. If the contents of an archive
46// are all text file, the entire archive is readable.
47
48struct Archive::Archive_header
49{
50 // The entry name.
51 char ar_name[16];
52 // The file modification time.
53 char ar_date[12];
54 // The user's UID in decimal.
55 char ar_uid[6];
56 // The user's GID in decimal.
57 char ar_gid[6];
58 // The file mode in octal.
59 char ar_mode[8];
60 // The file size in decimal.
61 char ar_size[10];
62 // The final magic code.
63 char ar_fmag[2];
64};
65
66// Archive methods.
67
68const char Archive::armag[sarmag] =
69{
70 '!', '<', 'a', 'r', 'c', 'h', '>', '\n'
71};
72
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73const char Archive::armagt[sarmag] =
74{
75 '!', '<', 't', 'h', 'i', 'n', '>', '\n'
76};
77
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78const char Archive::arfmag[2] = { '`', '\n' };
79
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80// Set up the archive: read the symbol map and the extended name
81// table.
82
83void
a1207466 84Archive::setup()
61ba1cf9 85{
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86 // We need to ignore empty archives.
87 if (this->input_file_->file().filesize() == sarmag)
a1207466 88 return;
3e95a404 89
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90 // The first member of the archive should be the symbol table.
91 std::string armap_name;
8383303e 92 section_size_type armap_size =
cb295612 93 convert_to_section_size_type(this->read_header(sarmag, false,
a1207466 94 &armap_name, NULL));
75f2446e 95 off_t off = sarmag;
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96 if (armap_name.empty())
97 {
98 this->read_armap(sarmag + sizeof(Archive_header), armap_size);
99 off = sarmag + sizeof(Archive_header) + armap_size;
100 }
45aa233b 101 else if (!this->input_file_->options().whole_archive())
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102 gold_error(_("%s: no archive symbol table (run ranlib)"),
103 this->name().c_str());
4973341a 104
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105 // See if there is an extended name table. We cache these views
106 // because it is likely that we will want to read the following
107 // header in the add_symbols routine.
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108 if ((off & 1) != 0)
109 ++off;
110 std::string xname;
cb295612 111 section_size_type extended_size =
a1207466 112 convert_to_section_size_type(this->read_header(off, true, &xname, NULL));
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113 if (xname == "/")
114 {
115 const unsigned char* p = this->get_view(off + sizeof(Archive_header),
39d0cb0e 116 extended_size, false, true);
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117 const char* px = reinterpret_cast<const char*>(p);
118 this->extended_names_.assign(px, extended_size);
119 }
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120}
121
122// Unlock any nested archives.
4973341a 123
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124void
125Archive::unlock_nested_archives()
126{
127 for (Nested_archive_table::iterator p = this->nested_archives_.begin();
128 p != this->nested_archives_.end();
129 ++p)
130 {
131 p->second->unlock(this->task_);
132 }
4973341a 133}
61ba1cf9 134
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135// Read the archive symbol map.
136
137void
8383303e 138Archive::read_armap(off_t start, section_size_type size)
4973341a 139{
61ba1cf9 140 // Read in the entire armap.
39d0cb0e 141 const unsigned char* p = this->get_view(start, size, true, false);
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142
143 // Numbers in the armap are always big-endian.
144 const elfcpp::Elf_Word* pword = reinterpret_cast<const elfcpp::Elf_Word*>(p);
f6ce93d6 145 unsigned int nsyms = elfcpp::Swap<32, true>::readval(pword);
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146 ++pword;
147
148 // Note that the addition is in units of sizeof(elfcpp::Elf_Word).
149 const char* pnames = reinterpret_cast<const char*>(pword + nsyms);
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150 section_size_type names_size =
151 reinterpret_cast<const char*>(p) + size - pnames;
9eb9fa57 152 this->armap_names_.assign(pnames, names_size);
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153
154 this->armap_.resize(nsyms);
155
8383303e 156 section_offset_type name_offset = 0;
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157 for (unsigned int i = 0; i < nsyms; ++i)
158 {
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159 this->armap_[i].name_offset = name_offset;
160 this->armap_[i].file_offset = elfcpp::Swap<32, true>::readval(pword);
161 name_offset += strlen(pnames + name_offset) + 1;
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162 ++pword;
163 }
164
8383303e 165 if (static_cast<section_size_type>(name_offset) > names_size)
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166 gold_error(_("%s: bad archive symbol table names"),
167 this->name().c_str());
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168
169 // This array keeps track of which symbols are for archive elements
170 // which we have already included in the link.
171 this->armap_checked_.resize(nsyms);
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172}
173
174// Read the header of an archive member at OFF. Fail if something
175// goes wrong. Return the size of the member. Set *PNAME to the name
176// of the member.
177
178off_t
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179Archive::read_header(off_t off, bool cache, std::string* pname,
180 off_t* nested_off)
61ba1cf9 181{
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182 const unsigned char* p = this->get_view(off, sizeof(Archive_header), true,
183 cache);
61ba1cf9 184 const Archive_header* hdr = reinterpret_cast<const Archive_header*>(p);
a1207466 185 return this->interpret_header(hdr, off, pname, nested_off);
4973341a 186}
61ba1cf9 187
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188// Interpret the header of HDR, the header of the archive member at
189// file offset OFF. Fail if something goes wrong. Return the size of
190// the member. Set *PNAME to the name of the member.
191
192off_t
193Archive::interpret_header(const Archive_header* hdr, off_t off,
a1207466 194 std::string* pname, off_t* nested_off)
4973341a 195{
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196 if (memcmp(hdr->ar_fmag, arfmag, sizeof arfmag) != 0)
197 {
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198 gold_error(_("%s: malformed archive header at %zu"),
199 this->name().c_str(), static_cast<size_t>(off));
200 return this->input_file_->file().filesize() - off;
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201 }
202
203 const int size_string_size = sizeof hdr->ar_size;
204 char size_string[size_string_size + 1];
205 memcpy(size_string, hdr->ar_size, size_string_size);
206 char* ps = size_string + size_string_size;
207 while (ps[-1] == ' ')
208 --ps;
209 *ps = '\0';
210
211 errno = 0;
212 char* end;
213 off_t member_size = strtol(size_string, &end, 10);
214 if (*end != '\0'
215 || member_size < 0
216 || (member_size == LONG_MAX && errno == ERANGE))
217 {
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218 gold_error(_("%s: malformed archive header size at %zu"),
219 this->name().c_str(), static_cast<size_t>(off));
220 return this->input_file_->file().filesize() - off;
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221 }
222
223 if (hdr->ar_name[0] != '/')
224 {
225 const char* name_end = strchr(hdr->ar_name, '/');
226 if (name_end == NULL
227 || name_end - hdr->ar_name >= static_cast<int>(sizeof hdr->ar_name))
228 {
a0c4fb0a 229 gold_error(_("%s: malformed archive header name at %zu"),
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230 this->name().c_str(), static_cast<size_t>(off));
231 return this->input_file_->file().filesize() - off;
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232 }
233 pname->assign(hdr->ar_name, name_end - hdr->ar_name);
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234 if (nested_off != NULL)
235 *nested_off = 0;
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236 }
237 else if (hdr->ar_name[1] == ' ')
238 {
239 // This is the symbol table.
240 pname->clear();
241 }
242 else if (hdr->ar_name[1] == '/')
243 {
244 // This is the extended name table.
245 pname->assign(1, '/');
246 }
247 else
248 {
249 errno = 0;
250 long x = strtol(hdr->ar_name + 1, &end, 10);
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251 long y = 0;
252 if (*end == ':')
253 y = strtol(end + 1, &end, 10);
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254 if (*end != ' '
255 || x < 0
256 || (x == LONG_MAX && errno == ERANGE)
257 || static_cast<size_t>(x) >= this->extended_names_.size())
258 {
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259 gold_error(_("%s: bad extended name index at %zu"),
260 this->name().c_str(), static_cast<size_t>(off));
261 return this->input_file_->file().filesize() - off;
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262 }
263
264 const char* name = this->extended_names_.data() + x;
a1207466 265 const char* name_end = strchr(name, '\n');
61ba1cf9 266 if (static_cast<size_t>(name_end - name) > this->extended_names_.size()
a1207466 267 || name_end[-1] != '/')
61ba1cf9 268 {
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269 gold_error(_("%s: bad extended name entry at header %zu"),
270 this->name().c_str(), static_cast<size_t>(off));
271 return this->input_file_->file().filesize() - off;
61ba1cf9 272 }
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273 pname->assign(name, name_end - 1 - name);
274 if (nested_off != NULL)
275 *nested_off = y;
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276 }
277
278 return member_size;
279}
280
281// Select members from the archive and add them to the link. We walk
282// through the elements in the archive map, and look each one up in
283// the symbol table. If it exists as a strong undefined symbol, we
284// pull in the corresponding element. We have to do this in a loop,
285// since pulling in one element may create new undefined symbols which
286// may be satisfied by other objects in the archive.
287
288void
7e1edb90 289Archive::add_symbols(Symbol_table* symtab, Layout* layout,
7d9e3d98 290 Input_objects* input_objects, Mapfile* mapfile)
61ba1cf9 291{
45aa233b 292 if (this->input_file_->options().whole_archive())
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293 return this->include_all_members(symtab, layout, input_objects,
294 mapfile);
4973341a 295
ead1e424 296 const size_t armap_size = this->armap_.size();
61ba1cf9 297
e243ffc6 298 // This is a quick optimization, since we usually see many symbols
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299 // in a row with the same offset. last_seen_offset holds the last
300 // offset we saw that was present in the seen_offsets_ set.
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301 off_t last_seen_offset = -1;
302
303 // Track which symbols in the symbol table we've already found to be
304 // defined.
e243ffc6 305
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306 bool added_new_object;
307 do
308 {
309 added_new_object = false;
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310 for (size_t i = 0; i < armap_size; ++i)
311 {
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312 if (this->armap_checked_[i])
313 continue;
9eb9fa57 314 if (this->armap_[i].file_offset == last_seen_offset)
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315 {
316 this->armap_checked_[i] = true;
317 continue;
318 }
9eb9fa57 319 if (this->seen_offsets_.find(this->armap_[i].file_offset)
a93d6d07 320 != this->seen_offsets_.end())
61ba1cf9 321 {
a93d6d07 322 this->armap_checked_[i] = true;
9eb9fa57 323 last_seen_offset = this->armap_[i].file_offset;
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324 continue;
325 }
326
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327 const char* sym_name = (this->armap_names_.data()
328 + this->armap_[i].name_offset);
329 Symbol* sym = symtab->lookup(sym_name);
61ba1cf9 330 if (sym == NULL)
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331 {
332 // Check whether the symbol was named in a -u option.
333 if (!parameters->options().is_undefined(sym_name))
334 continue;
335 }
ead1e424 336 else if (!sym->is_undefined())
61ba1cf9 337 {
a93d6d07 338 this->armap_checked_[i] = true;
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339 continue;
340 }
341 else if (sym->binding() == elfcpp::STB_WEAK)
342 continue;
343
344 // We want to include this object in the link.
9eb9fa57 345 last_seen_offset = this->armap_[i].file_offset;
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346 this->seen_offsets_.insert(last_seen_offset);
347 this->armap_checked_[i] = true;
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348
349 std::string why;
350 if (sym == NULL)
351 {
352 why = "-u ";
353 why += sym_name;
354 }
7e1edb90 355 this->include_member(symtab, layout, input_objects,
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356 last_seen_offset, mapfile, sym, why.c_str());
357
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358 added_new_object = true;
359 }
360 }
361 while (added_new_object);
362}
363
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364// Include all the archive members in the link. This is for --whole-archive.
365
366void
7e1edb90 367Archive::include_all_members(Symbol_table* symtab, Layout* layout,
7d9e3d98 368 Input_objects* input_objects, Mapfile* mapfile)
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369{
370 off_t off = sarmag;
82dcae9d 371 off_t filesize = this->input_file_->file().filesize();
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372 while (true)
373 {
f5c3f225 374 if (filesize - off < static_cast<off_t>(sizeof(Archive_header)))
4973341a 375 {
82dcae9d 376 if (filesize != off)
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377 gold_error(_("%s: short archive header at %zu"),
378 this->name().c_str(), static_cast<size_t>(off));
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379 break;
380 }
381
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382 unsigned char hdr_buf[sizeof(Archive_header)];
383 this->input_file_->file().read(off, sizeof(Archive_header), hdr_buf);
384
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385 const Archive_header* hdr =
386 reinterpret_cast<const Archive_header*>(hdr_buf);
4973341a 387 std::string name;
a1207466 388 off_t size = this->interpret_header(hdr, off, &name, NULL);
3e90f135 389 bool special_member = false;
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390 if (name.empty())
391 {
392 // Symbol table.
3e90f135 393 special_member = true;
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394 }
395 else if (name == "/")
396 {
397 // Extended name table.
3e90f135 398 special_member = true;
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399 }
400 else
7d9e3d98
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401 this->include_member(symtab, layout, input_objects, off,
402 mapfile, NULL, "--whole-archive");
4973341a 403
a1207466 404 off += sizeof(Archive_header);
3e90f135 405 if (special_member || !this->is_thin_archive_)
a1207466 406 off += size;
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407 if ((off & 1) != 0)
408 ++off;
409 }
410}
411
61ba1cf9 412// Include an archive member in the link. OFF is the file offset of
7d9e3d98 413// the member header. WHY is the reason we are including this member.
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414
415void
7e1edb90 416Archive::include_member(Symbol_table* symtab, Layout* layout,
7d9e3d98
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417 Input_objects* input_objects, off_t off,
418 Mapfile* mapfile, Symbol* sym, const char* why)
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419{
420 std::string n;
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421 off_t nested_off;
422 this->read_header(off, false, &n, &nested_off);
61ba1cf9 423
7d9e3d98
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424 if (mapfile != NULL)
425 mapfile->report_include_archive_member(this, n, sym, why);
426
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427 Input_file* input_file;
428 off_t memoff;
429
430 if (!this->is_thin_archive_)
431 {
432 input_file = this->input_file_;
433 memoff = off + static_cast<off_t>(sizeof(Archive_header));
434 }
435 else
436 {
437 // Adjust a relative pathname so that it is relative
438 // to the directory containing the archive.
439 if (!IS_ABSOLUTE_PATH(n.c_str()))
440 {
441 const char *arch_path = this->name().c_str();
442 const char *basename = lbasename(arch_path);
443 if (basename > arch_path)
444 n.replace(0, 0, this->name().substr(0, basename - arch_path));
445 }
446 if (nested_off > 0)
447 {
448 // This is a member of a nested archive. Open the containing
449 // archive if we don't already have it open, then do a recursive
450 // call to include the member from that archive.
451 Archive* arch;
452 Nested_archive_table::const_iterator p =
453 this->nested_archives_.find(n);
454 if (p != this->nested_archives_.end())
455 arch = p->second;
456 else
457 {
458 Input_file_argument* input_file_arg =
459 new Input_file_argument(n.c_str(), false, "", false,
460 parameters->options());
461 input_file = new Input_file(input_file_arg);
462 if (!input_file->open(parameters->options(), *this->dirpath_,
463 this->task_))
464 return;
465 arch = new Archive(n, input_file, false, this->dirpath_,
466 this->task_);
467 arch->setup();
468 std::pair<Nested_archive_table::iterator, bool> ins =
469 this->nested_archives_.insert(std::make_pair(n, arch));
470 gold_assert(ins.second);
471 }
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472 arch->include_member(symtab, layout, input_objects, nested_off,
473 NULL, NULL, NULL);
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474 return;
475 }
476 // This is an external member of a thin archive. Open the
477 // file as a regular relocatable object file.
478 Input_file_argument* input_file_arg =
479 new Input_file_argument(n.c_str(), false, "", false,
480 this->input_file_->options());
481 input_file = new Input_file(input_file_arg);
482 if (!input_file->open(parameters->options(), *this->dirpath_,
483 this->task_))
484 {
485 return;
486 }
487 memoff = 0;
488 }
61ba1cf9 489
a1207466 490 off_t filesize = input_file->file().filesize();
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491 int read_size = elfcpp::Elf_sizes<64>::ehdr_size;
492 if (filesize - memoff < read_size)
493 read_size = filesize - memoff;
494
495 if (read_size < 4)
61ba1cf9 496 {
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497 gold_error(_("%s: member at %zu is not an ELF object"),
498 this->name().c_str(), static_cast<size_t>(off));
499 return;
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500 }
501
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502 const unsigned char* ehdr = input_file->file().get_view(memoff, 0, read_size,
503 true, false);
82dcae9d 504
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505 static unsigned char elfmagic[4] =
506 {
507 elfcpp::ELFMAG0, elfcpp::ELFMAG1,
508 elfcpp::ELFMAG2, elfcpp::ELFMAG3
509 };
7ef73768 510 if (memcmp(ehdr, elfmagic, 4) != 0)
61ba1cf9 511 {
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512 gold_error(_("%s: member at %zu is not an ELF object"),
513 this->name().c_str(), static_cast<size_t>(off));
514 return;
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515 }
516
92e059d8 517 Object* obj = make_elf_object((std::string(this->input_file_->filename())
61ba1cf9 518 + "(" + n + ")"),
7ef73768 519 input_file, memoff, ehdr, read_size);
61ba1cf9 520
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521 if (input_objects->add_object(obj))
522 {
523 Read_symbols_data sd;
524 obj->read_symbols(&sd);
525 obj->layout(symtab, layout, &sd);
526 obj->add_symbols(symtab, &sd);
527 }
528 else
529 {
530 // FIXME: We need to close the descriptor here.
531 delete obj;
532 }
61ba1cf9 533
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534 if (this->is_thin_archive_)
535 {
536 // Opening the file locked it. Unlock it now.
537 input_file->file().unlock(this->task_);
538 }
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539}
540
541// Add_archive_symbols methods.
542
543Add_archive_symbols::~Add_archive_symbols()
544{
545 if (this->this_blocker_ != NULL)
546 delete this->this_blocker_;
547 // next_blocker_ is deleted by the task associated with the next
548 // input file.
549}
550
551// Return whether we can add the archive symbols. We are blocked by
552// this_blocker_. We block next_blocker_. We also lock the file.
553
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554Task_token*
555Add_archive_symbols::is_runnable()
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556{
557 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
17a1d0a9
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558 return this->this_blocker_;
559 return NULL;
61ba1cf9
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560}
561
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562void
563Add_archive_symbols::locks(Task_locker* tl)
61ba1cf9 564{
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565 tl->add(this, this->next_blocker_);
566 tl->add(this, this->archive_->token());
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567}
568
569void
570Add_archive_symbols::run(Workqueue*)
571{
7e1edb90 572 this->archive_->add_symbols(this->symtab_, this->layout_,
7d9e3d98 573 this->input_objects_, this->mapfile_);
ead1e424 574
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575 this->archive_->unlock_nested_archives();
576
17a1d0a9 577 this->archive_->release();
39d0cb0e 578 this->archive_->clear_uncached_views();
17a1d0a9 579
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580 if (this->input_group_ != NULL)
581 this->input_group_->add_archive(this->archive_);
582 else
583 {
584 // We no longer need to know about this archive.
585 delete this->archive_;
c7912668 586 this->archive_ = NULL;
ead1e424 587 }
61ba1cf9
ILT
588}
589
590} // End namespace gold.
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