1 // archive.cc -- archive support for gold
21 // The header of an entry in the archive. This is all readable text,
22 // padded with spaces where necesary. If the contents of an archive
23 // are all text file, the entire archive is readable.
25 struct Archive::Archive_header
29 // The file modification time.
31 // The user's UID in decimal.
33 // The user's GID in decimal.
35 // The file mode in octal.
37 // The file size in decimal.
39 // The final magic code.
45 const char Archive::armag[sarmag] =
47 '!', '<', 'a', 'r', 'c', 'h', '>', '\n'
50 const char Archive::arfmag[2] = { '`', '\n' };
52 // Set up the archive: read the symbol map and the extended name
58 // The first member of the archive should be the symbol table.
59 std::string armap_name;
60 off_t armap_size = this->read_header(sarmag, &armap_name);
62 if (armap_name.empty())
64 this->read_armap(sarmag + sizeof(Archive_header), armap_size);
65 off = sarmag + sizeof(Archive_header) + armap_size;
67 else if (!this->input_file_->options().include_whole_archive())
69 fprintf(stderr, _("%s: %s: no archive symbol table (run ranlib)\n"),
70 program_name, this->name().c_str());
76 // See if there is an extended name table.
80 off_t extended_size = this->read_header(off, &xname);
83 const unsigned char* p = this->get_view(off + sizeof(Archive_header),
85 const char* px = reinterpret_cast<const char*>(p);
86 this->extended_names_.assign(px, extended_size);
89 // Opening the file locked it. Unlock it now.
90 this->input_file_->file().unlock();
93 // Read the archive symbol map.
96 Archive::read_armap(off_t start, off_t size)
98 // Read in the entire armap.
99 const unsigned char* p = this->get_view(start, size);
101 // Numbers in the armap are always big-endian.
102 const elfcpp::Elf_Word* pword = reinterpret_cast<const elfcpp::Elf_Word*>(p);
103 unsigned int nsyms = elfcpp::Swap<32, true>::readval(pword);
106 // Note that the addition is in units of sizeof(elfcpp::Elf_Word).
107 const char* pnames = reinterpret_cast<const char*>(pword + nsyms);
109 this->armap_.resize(nsyms);
111 for (unsigned int i = 0; i < nsyms; ++i)
113 this->armap_[i].name = pnames;
114 this->armap_[i].offset = elfcpp::Swap<32, true>::readval(pword);
115 pnames += strlen(pnames) + 1;
119 if (reinterpret_cast<const unsigned char*>(pnames) - p > size)
121 fprintf(stderr, _("%s: %s: bad archive symbol table names\n"),
122 program_name, this->name().c_str());
126 // This array keeps track of which symbols are for archive elements
127 // which we have already included in the link.
128 this->armap_checked_.resize(nsyms);
131 // Read the header of an archive member at OFF. Fail if something
132 // goes wrong. Return the size of the member. Set *PNAME to the name
136 Archive::read_header(off_t off, std::string* pname)
138 const unsigned char* p = this->get_view(off, sizeof(Archive_header));
139 const Archive_header* hdr = reinterpret_cast<const Archive_header*>(p);
140 return this->interpret_header(hdr, off, pname);
143 // Interpret the header of HDR, the header of the archive member at
144 // file offset OFF. Fail if something goes wrong. Return the size of
145 // the member. Set *PNAME to the name of the member.
148 Archive::interpret_header(const Archive_header* hdr, off_t off,
151 if (memcmp(hdr->ar_fmag, arfmag, sizeof arfmag) != 0)
153 fprintf(stderr, _("%s; %s: malformed archive header at %ld\n"),
154 program_name, this->name().c_str(),
155 static_cast<long>(off));
159 const int size_string_size = sizeof hdr->ar_size;
160 char size_string[size_string_size + 1];
161 memcpy(size_string, hdr->ar_size, size_string_size);
162 char* ps = size_string + size_string_size;
163 while (ps[-1] == ' ')
169 off_t member_size = strtol(size_string, &end, 10);
172 || (member_size == LONG_MAX && errno == ERANGE))
174 fprintf(stderr, _("%s: %s: malformed archive header size at %ld\n"),
175 program_name, this->name().c_str(),
176 static_cast<long>(off));
180 if (hdr->ar_name[0] != '/')
182 const char* name_end = strchr(hdr->ar_name, '/');
184 || name_end - hdr->ar_name >= static_cast<int>(sizeof hdr->ar_name))
186 fprintf(stderr, _("%s: %s: malformed archive header name at %ld\n"),
187 program_name, this->name().c_str(),
188 static_cast<long>(off));
191 pname->assign(hdr->ar_name, name_end - hdr->ar_name);
193 else if (hdr->ar_name[1] == ' ')
195 // This is the symbol table.
198 else if (hdr->ar_name[1] == '/')
200 // This is the extended name table.
201 pname->assign(1, '/');
206 long x = strtol(hdr->ar_name + 1, &end, 10);
209 || (x == LONG_MAX && errno == ERANGE)
210 || static_cast<size_t>(x) >= this->extended_names_.size())
212 fprintf(stderr, _("%s: %s: bad extended name index at %ld\n"),
213 program_name, this->name().c_str(),
214 static_cast<long>(off));
218 const char* name = this->extended_names_.data() + x;
219 const char* name_end = strchr(name, '/');
220 if (static_cast<size_t>(name_end - name) > this->extended_names_.size()
221 || name_end[1] != '\n')
223 fprintf(stderr, _("%s: %s: bad extended name entry at header %ld\n"),
224 program_name, this->name().c_str(),
225 static_cast<long>(off));
228 pname->assign(name, name_end - name);
234 // Select members from the archive and add them to the link. We walk
235 // through the elements in the archive map, and look each one up in
236 // the symbol table. If it exists as a strong undefined symbol, we
237 // pull in the corresponding element. We have to do this in a loop,
238 // since pulling in one element may create new undefined symbols which
239 // may be satisfied by other objects in the archive.
242 Archive::add_symbols(Symbol_table* symtab, Layout* layout,
243 Input_objects* input_objects)
245 if (this->input_file_->options().include_whole_archive())
246 return this->include_all_members(symtab, layout, input_objects);
248 const size_t armap_size = this->armap_.size();
250 // This is a quick optimization, since we usually see many symbols
251 // in a row with the same offset. last_seen_offset holds the last
252 // offset we saw that was present in the seen_offsets_ set.
253 off_t last_seen_offset = -1;
255 // Track which symbols in the symbol table we've already found to be
258 bool added_new_object;
261 added_new_object = false;
262 for (size_t i = 0; i < armap_size; ++i)
264 if (this->armap_checked_[i])
266 if (this->armap_[i].offset == last_seen_offset)
268 this->armap_checked_[i] = true;
271 if (this->seen_offsets_.find(this->armap_[i].offset)
272 != this->seen_offsets_.end())
274 this->armap_checked_[i] = true;
275 last_seen_offset = this->armap_[i].offset;
279 Symbol* sym = symtab->lookup(this->armap_[i].name);
282 else if (!sym->is_undefined())
284 this->armap_checked_[i] = true;
287 else if (sym->binding() == elfcpp::STB_WEAK)
290 // We want to include this object in the link.
291 last_seen_offset = this->armap_[i].offset;
292 this->seen_offsets_.insert(last_seen_offset);
293 this->armap_checked_[i] = true;
294 this->include_member(symtab, layout, input_objects,
296 added_new_object = true;
299 while (added_new_object);
302 // Include all the archive members in the link. This is for --whole-archive.
305 Archive::include_all_members(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(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(Symbol_table* symtab, Layout* layout,
352 Input_objects* input_objects, off_t off)
355 this->read_header(off, &n);
357 size_t memoff = off + sizeof(Archive_header);
359 // Read enough of the file to pick up the entire ELF header.
360 int ehdr_size = elfcpp::Elf_sizes<64>::ehdr_size;
362 const unsigned char* p = this->input_file_->file().get_view(memoff,
367 fprintf(stderr, _("%s: %s: member at %ld is not an ELF object"),
368 program_name, this->name().c_str(),
369 static_cast<long>(off));
373 static unsigned char elfmagic[4] =
375 elfcpp::ELFMAG0, elfcpp::ELFMAG1,
376 elfcpp::ELFMAG2, elfcpp::ELFMAG3
378 if (memcmp(p, elfmagic, 4) != 0)
380 fprintf(stderr, _("%s: %s: member at %ld is not an ELF object"),
381 program_name, this->name().c_str(),
382 static_cast<long>(off));
386 Object* obj = make_elf_object((std::string(this->input_file_->filename())
388 this->input_file_, memoff, p, bytes);
390 input_objects->add_object(obj);
392 Read_symbols_data sd;
393 obj->read_symbols(&sd);
394 obj->layout(symtab, layout, &sd);
395 obj->add_symbols(symtab, &sd);
398 // Add_archive_symbols methods.
400 Add_archive_symbols::~Add_archive_symbols()
402 if (this->this_blocker_ != NULL)
403 delete this->this_blocker_;
404 // next_blocker_ is deleted by the task associated with the next
408 // Return whether we can add the archive symbols. We are blocked by
409 // this_blocker_. We block next_blocker_. We also lock the file.
411 Task::Is_runnable_type
412 Add_archive_symbols::is_runnable(Workqueue*)
414 if (this->this_blocker_ != NULL && this->this_blocker_->is_blocked())
419 class Add_archive_symbols::Add_archive_symbols_locker : public Task_locker
422 Add_archive_symbols_locker(Task_token& token, Workqueue* workqueue,
424 : blocker_(token, workqueue), filelock_(file)
428 Task_locker_block blocker_;
429 Task_locker_obj<File_read> filelock_;
433 Add_archive_symbols::locks(Workqueue* workqueue)
435 return new Add_archive_symbols_locker(*this->next_blocker_,
437 this->archive_->file());
441 Add_archive_symbols::run(Workqueue*)
443 this->archive_->add_symbols(this->symtab_, this->layout_,
444 this->input_objects_);
446 if (this->input_group_ != NULL)
447 this->input_group_->add_archive(this->archive_);
450 // We no longer need to know about this archive.
451 delete this->archive_;
455 } // End namespace gold.