1 // archive.cc -- archive support for gold
20 // The header of an entry in the archive. This is all readable text,
21 // padded with spaces where necesary. If the contents of an archive
22 // are all text file, the entire archive is readable.
24 struct Archive::Archive_header
28 // The file modification time.
30 // The user's UID in decimal.
32 // The user's GID in decimal.
34 // The file mode in octal.
36 // The file size in decimal.
38 // The final magic code.
44 const char Archive::armag[sarmag] =
46 '!', '<', 'a', 'r', 'c', 'h', '>', '\n'
49 const char Archive::arfmag[2] = { '`', '\n' };
51 // Set up the archive: read the symbol map and the extended name
57 // The first member of the archive should be the symbol table.
58 std::string armap_name;
59 off_t armap_size = this->read_header(sarmag, &armap_name);
61 if (armap_name.empty())
63 this->read_armap(sarmag + sizeof(Archive_header), armap_size);
64 off = sarmag + sizeof(Archive_header) + armap_size;
66 else if (!this->input_file_->options().include_whole_archive())
68 fprintf(stderr, _("%s: %s: no archive symbol table (run ranlib)\n"),
69 program_name, this->name().c_str());
75 // See if there is an extended name table.
79 off_t extended_size = this->read_header(off, &xname);
82 const unsigned char* p = this->get_view(off + sizeof(Archive_header),
84 const char* px = reinterpret_cast<const char*>(p);
85 this->extended_names_.assign(px, extended_size);
88 // Opening the file locked it. Unlock it now.
89 this->input_file_->file().unlock();
92 // Read the archive symbol map.
95 Archive::read_armap(off_t start, off_t size)
97 // Read in the entire armap.
98 const unsigned char* p = this->get_view(start, size);
100 // Numbers in the armap are always big-endian.
101 const elfcpp::Elf_Word* pword = reinterpret_cast<const elfcpp::Elf_Word*>(p);
102 unsigned int nsyms = elfcpp::Swap<32, true>::readval(pword);
105 // Note that the addition is in units of sizeof(elfcpp::Elf_Word).
106 const char* pnames = reinterpret_cast<const char*>(pword + nsyms);
108 this->armap_.resize(nsyms);
110 for (unsigned int i = 0; i < nsyms; ++i)
112 this->armap_[i].name = pnames;
113 this->armap_[i].offset = elfcpp::Swap<32, true>::readval(pword);
114 pnames += strlen(pnames) + 1;
118 if (reinterpret_cast<const unsigned char*>(pnames) - p > size)
120 fprintf(stderr, _("%s: %s: bad archive symbol table names\n"),
121 program_name, this->name().c_str());
125 // This array keeps track of which symbols are for archive elements
126 // which we have already included in the link.
127 this->armap_checked_.resize(nsyms);
130 // Read the header of an archive member at OFF. Fail if something
131 // goes wrong. Return the size of the member. Set *PNAME to the name
135 Archive::read_header(off_t off, std::string* pname)
137 const unsigned char* p = this->get_view(off, sizeof(Archive_header));
138 const Archive_header* hdr = reinterpret_cast<const Archive_header*>(p);
139 return this->interpret_header(hdr, off, pname);
142 // Interpret the header of HDR, the header of the archive member at
143 // file offset OFF. Fail if something goes wrong. Return the size of
144 // the member. Set *PNAME to the name of the member.
147 Archive::interpret_header(const Archive_header* hdr, off_t off,
150 if (memcmp(hdr->ar_fmag, arfmag, sizeof arfmag) != 0)
152 fprintf(stderr, _("%s; %s: malformed archive header at %ld\n"),
153 program_name, this->name().c_str(),
154 static_cast<long>(off));
158 const int size_string_size = sizeof hdr->ar_size;
159 char size_string[size_string_size + 1];
160 memcpy(size_string, hdr->ar_size, size_string_size);
161 char* ps = size_string + size_string_size;
162 while (ps[-1] == ' ')
168 off_t member_size = strtol(size_string, &end, 10);
171 || (member_size == LONG_MAX && errno == ERANGE))
173 fprintf(stderr, _("%s: %s: malformed archive header size at %ld\n"),
174 program_name, this->name().c_str(),
175 static_cast<long>(off));
179 if (hdr->ar_name[0] != '/')
181 const char* name_end = strchr(hdr->ar_name, '/');
183 || name_end - hdr->ar_name >= static_cast<int>(sizeof hdr->ar_name))
185 fprintf(stderr, _("%s: %s: malformed archive header name at %ld\n"),
186 program_name, this->name().c_str(),
187 static_cast<long>(off));
190 pname->assign(hdr->ar_name, name_end - hdr->ar_name);
192 else if (hdr->ar_name[1] == ' ')
194 // This is the symbol table.
197 else if (hdr->ar_name[1] == '/')
199 // This is the extended name table.
200 pname->assign(1, '/');
205 long x = strtol(hdr->ar_name + 1, &end, 10);
208 || (x == LONG_MAX && errno == ERANGE)
209 || static_cast<size_t>(x) >= this->extended_names_.size())
211 fprintf(stderr, _("%s: %s: bad extended name index at %ld\n"),
212 program_name, this->name().c_str(),
213 static_cast<long>(off));
217 const char* name = this->extended_names_.data() + x;
218 const char* name_end = strchr(name, '/');
219 if (static_cast<size_t>(name_end - name) > this->extended_names_.size()
220 || name_end[1] != '\n')
222 fprintf(stderr, _("%s: %s: bad extended name entry at header %ld\n"),
223 program_name, this->name().c_str(),
224 static_cast<long>(off));
227 pname->assign(name, name_end - name);
233 // Select members from the archive and add them to the link. We walk
234 // through the elements in the archive map, and look each one up in
235 // the symbol table. If it exists as a strong undefined symbol, we
236 // pull in the corresponding element. We have to do this in a loop,
237 // since pulling in one element may create new undefined symbols which
238 // may be satisfied by other objects in the archive.
241 Archive::add_symbols(const General_options& options, Symbol_table* symtab,
242 Layout* layout, Input_objects* input_objects)
244 if (this->input_file_->options().include_whole_archive())
245 return this->include_all_members(options, symtab, layout, input_objects);
247 const size_t armap_size = this->armap_.size();
249 // This is a quick optimization, since we usually see many symbols
250 // in a row with the same offset. last_seen holds the last offset
251 // we saw that was present in the seen_ set.
252 off_t last_seen_offset = -1;
254 // Track which symbols in the symbol table we've already found to be
257 bool added_new_object;
260 added_new_object = false;
261 for (size_t i = 0; i < armap_size; ++i)
263 if (this->armap_checked_[i])
265 if (this->armap_[i].offset == last_seen_offset)
267 this->armap_checked_[i] = true;
270 if (this->seen_offsets_.find(this->armap_[i].offset)
271 != this->seen_offsets_.end())
273 this->armap_checked_[i] = true;
274 last_seen_offset = this->armap_[i].offset;
278 Symbol* sym = symtab->lookup(this->armap_[i].name);
281 else if (!sym->is_undefined())
283 this->armap_checked_[i] = true;
286 else if (sym->binding() == elfcpp::STB_WEAK)
289 // We want to include this object in the link.
290 last_seen_offset = this->armap_[i].offset;
291 this->seen_offsets_.insert(last_seen_offset);
292 this->armap_checked_[i] = true;
293 this->include_member(options, symtab, layout, input_objects,
295 added_new_object = true;
298 while (added_new_object);
301 // Include all the archive members in the link. This is for --whole-archive.
304 Archive::include_all_members(const General_options& options,
305 Symbol_table* symtab, Layout* layout,
306 Input_objects* input_objects)
312 const unsigned char* p = this->get_view(off, sizeof(Archive_header),
314 if (bytes < sizeof(Archive_header))
318 fprintf(stderr, _("%s: %s: short archive header at %ld\n"),
319 program_name, this->name().c_str(),
320 static_cast<long>(off));
327 const Archive_header* hdr = reinterpret_cast<const Archive_header*>(p);
329 off_t size = this->interpret_header(hdr, off, &name);
334 else if (name == "/")
336 // Extended name table.
339 this->include_member(options, symtab, layout, input_objects, off);
341 off += sizeof(Archive_header) + size;
347 // Include an archive member in the link. OFF is the file offset of
348 // the member header.
351 Archive::include_member(const General_options& options, Symbol_table* symtab,
352 Layout* layout, Input_objects* input_objects,
356 this->read_header(off, &n);
358 size_t memoff = off + sizeof(Archive_header);
360 // Read enough of the file to pick up the entire ELF header.
361 int ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size;
363 const unsigned char* p = this->input_file_->file().get_view(memoff,
368 fprintf(stderr, _("%s: %s: member at %ld is not an ELF object"),
369 program_name, this->name().c_str(),
370 static_cast<long>(off));
374 static unsigned char elfmagic[4] =
376 elfcpp::ELFMAG0, elfcpp::ELFMAG1,
377 elfcpp::ELFMAG2, elfcpp::ELFMAG3
379 if (memcmp(p, elfmagic, 4) != 0)
381 fprintf(stderr, _("%s: %s: member at %ld is not an ELF object"),
382 program_name, this->name().c_str(),
383 static_cast<long>(off));
387 Object* obj = make_elf_object((std::string(this->input_file_->filename())
389 this->input_file_, memoff, p, bytes);
391 input_objects->add_object(obj);
393 Read_symbols_data sd;
394 obj->read_symbols(&sd);
395 obj->layout(options, symtab, layout, &sd);
396 obj->add_symbols(symtab, &sd);
399 // Add_archive_symbols methods.
401 Add_archive_symbols::~Add_archive_symbols()
403 if (this->this_blocker_ != NULL)
404 delete this->this_blocker_;
405 // next_blocker_ is deleted by the task associated with the next
409 // Return whether we can add the archive symbols. We are blocked by
410 // this_blocker_. We block next_blocker_. We also lock the file.
412 Task::Is_runnable_type
413 Add_archive_symbols::is_runnable(Workqueue*)
415 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
420 class Add_archive_symbols::Add_archive_symbols_locker : public Task_locker
423 Add_archive_symbols_locker(Task_token& token, Workqueue* workqueue,
425 : blocker_(token, workqueue), filelock_(file)
429 Task_locker_block blocker_;
430 Task_locker_obj<File_read> filelock_;
434 Add_archive_symbols::locks(Workqueue* workqueue)
436 return new Add_archive_symbols_locker(*this->next_blocker_,
438 this->archive_->file());
442 Add_archive_symbols::run(Workqueue*)
444 this->archive_->add_symbols(this->options_, this->symtab_, this->layout_,
445 this->input_objects_);
447 if (this->input_group_ != NULL)
448 this->input_group_->add_archive(this->archive_);
451 // We no longer need to know about this archive.
452 delete this->archive_;
456 } // End namespace gold.