1 //===-- ObjectContainerBSDArchive.cpp -------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "ObjectContainerBSDArchive.h" 10 11 #if defined(_WIN32) || defined(__ANDROID__) 12 // Defines from ar, missing on Windows 13 #define ARMAG "!<arch>\n" 14 #define SARMAG 8 15 #define ARFMAG "`\n" 16 17 typedef struct ar_hdr { 18 char ar_name[16]; 19 char ar_date[12]; 20 char ar_uid[6], ar_gid[6]; 21 char ar_mode[8]; 22 char ar_size[10]; 23 char ar_fmag[2]; 24 } ar_hdr; 25 #else 26 #include <ar.h> 27 #endif 28 29 #include "lldb/Core/Module.h" 30 #include "lldb/Core/ModuleSpec.h" 31 #include "lldb/Core/PluginManager.h" 32 #include "lldb/Host/FileSystem.h" 33 #include "lldb/Symbol/ObjectFile.h" 34 #include "lldb/Utility/ArchSpec.h" 35 #include "lldb/Utility/Stream.h" 36 #include "lldb/Utility/Timer.h" 37 38 #include "llvm/Support/MemoryBuffer.h" 39 40 using namespace lldb; 41 using namespace lldb_private; 42 43 LLDB_PLUGIN_DEFINE(ObjectContainerBSDArchive) 44 45 ObjectContainerBSDArchive::Object::Object() 46 : ar_name(), modification_time(0), uid(0), gid(0), mode(0), size(0), 47 file_offset(0), file_size(0) {} 48 49 void ObjectContainerBSDArchive::Object::Clear() { 50 ar_name.Clear(); 51 modification_time = 0; 52 uid = 0; 53 gid = 0; 54 mode = 0; 55 size = 0; 56 file_offset = 0; 57 file_size = 0; 58 } 59 60 lldb::offset_t 61 ObjectContainerBSDArchive::Object::Extract(const DataExtractor &data, 62 lldb::offset_t offset) { 63 size_t ar_name_len = 0; 64 std::string str; 65 char *err; 66 67 // File header 68 // 69 // The common format is as follows. 70 // 71 // Offset Length Name Format 72 // 0 16 File name ASCII right padded with spaces (no spaces 73 // allowed in file name) 74 // 16 12 File mod Decimal as cstring right padded with 75 // spaces 76 // 28 6 Owner ID Decimal as cstring right padded with 77 // spaces 78 // 34 6 Group ID Decimal as cstring right padded with 79 // spaces 80 // 40 8 File mode Octal as cstring right padded with 81 // spaces 82 // 48 10 File byte size Decimal as cstring right padded with 83 // spaces 84 // 58 2 File magic 0x60 0x0A 85 86 // Make sure there is enough data for the file header and bail if not 87 if (!data.ValidOffsetForDataOfSize(offset, 60)) 88 return LLDB_INVALID_OFFSET; 89 90 str.assign((const char *)data.GetData(&offset, 16), 16); 91 if (llvm::StringRef(str).startswith("#1/")) { 92 // If the name is longer than 16 bytes, or contains an embedded space then 93 // it will use this format where the length of the name is here and the 94 // name characters are after this header. 95 ar_name_len = strtoul(str.c_str() + 3, &err, 10); 96 } else { 97 // Strip off any trailing spaces. 98 const size_t last_pos = str.find_last_not_of(' '); 99 if (last_pos != std::string::npos) { 100 if (last_pos + 1 < 16) 101 str.erase(last_pos + 1); 102 } 103 ar_name.SetCString(str.c_str()); 104 } 105 106 str.assign((const char *)data.GetData(&offset, 12), 12); 107 modification_time = strtoul(str.c_str(), &err, 10); 108 109 str.assign((const char *)data.GetData(&offset, 6), 6); 110 uid = strtoul(str.c_str(), &err, 10); 111 112 str.assign((const char *)data.GetData(&offset, 6), 6); 113 gid = strtoul(str.c_str(), &err, 10); 114 115 str.assign((const char *)data.GetData(&offset, 8), 8); 116 mode = strtoul(str.c_str(), &err, 8); 117 118 str.assign((const char *)data.GetData(&offset, 10), 10); 119 size = strtoul(str.c_str(), &err, 10); 120 121 str.assign((const char *)data.GetData(&offset, 2), 2); 122 if (str == ARFMAG) { 123 if (ar_name_len > 0) { 124 const void *ar_name_ptr = data.GetData(&offset, ar_name_len); 125 // Make sure there was enough data for the string value and bail if not 126 if (ar_name_ptr == nullptr) 127 return LLDB_INVALID_OFFSET; 128 str.assign((const char *)ar_name_ptr, ar_name_len); 129 ar_name.SetCString(str.c_str()); 130 } 131 file_offset = offset; 132 file_size = size - ar_name_len; 133 return offset; 134 } 135 return LLDB_INVALID_OFFSET; 136 } 137 138 ObjectContainerBSDArchive::Archive::Archive(const lldb_private::ArchSpec &arch, 139 const llvm::sys::TimePoint<> &time, 140 lldb::offset_t file_offset, 141 lldb_private::DataExtractor &data) 142 : m_arch(arch), m_modification_time(time), m_file_offset(file_offset), 143 m_objects(), m_data(data) {} 144 145 ObjectContainerBSDArchive::Archive::~Archive() {} 146 147 size_t ObjectContainerBSDArchive::Archive::ParseObjects() { 148 DataExtractor &data = m_data; 149 std::string str; 150 lldb::offset_t offset = 0; 151 str.assign((const char *)data.GetData(&offset, SARMAG), SARMAG); 152 if (str == ARMAG) { 153 Object obj; 154 do { 155 offset = obj.Extract(data, offset); 156 if (offset == LLDB_INVALID_OFFSET) 157 break; 158 size_t obj_idx = m_objects.size(); 159 m_objects.push_back(obj); 160 // Insert all of the C strings out of order for now... 161 m_object_name_to_index_map.Append(obj.ar_name, obj_idx); 162 offset += obj.file_size; 163 obj.Clear(); 164 } while (data.ValidOffset(offset)); 165 166 // Now sort all of the object name pointers 167 m_object_name_to_index_map.Sort(); 168 } 169 return m_objects.size(); 170 } 171 172 ObjectContainerBSDArchive::Object * 173 ObjectContainerBSDArchive::Archive::FindObject( 174 ConstString object_name, const llvm::sys::TimePoint<> &object_mod_time) { 175 const ObjectNameToIndexMap::Entry *match = 176 m_object_name_to_index_map.FindFirstValueForName(object_name); 177 if (!match) 178 return nullptr; 179 if (object_mod_time == llvm::sys::TimePoint<>()) 180 return &m_objects[match->value]; 181 182 const uint64_t object_modification_date = llvm::sys::toTimeT(object_mod_time); 183 if (m_objects[match->value].modification_time == object_modification_date) 184 return &m_objects[match->value]; 185 186 const ObjectNameToIndexMap::Entry *next_match = 187 m_object_name_to_index_map.FindNextValueForName(match); 188 while (next_match) { 189 if (m_objects[next_match->value].modification_time == 190 object_modification_date) 191 return &m_objects[next_match->value]; 192 next_match = m_object_name_to_index_map.FindNextValueForName(next_match); 193 } 194 195 return nullptr; 196 } 197 198 ObjectContainerBSDArchive::Archive::shared_ptr 199 ObjectContainerBSDArchive::Archive::FindCachedArchive( 200 const FileSpec &file, const ArchSpec &arch, 201 const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset) { 202 std::lock_guard<std::recursive_mutex> guard(Archive::GetArchiveCacheMutex()); 203 shared_ptr archive_sp; 204 Archive::Map &archive_map = Archive::GetArchiveCache(); 205 Archive::Map::iterator pos = archive_map.find(file); 206 // Don't cache a value for "archive_map.end()" below since we might delete an 207 // archive entry... 208 while (pos != archive_map.end() && pos->first == file) { 209 bool match = true; 210 if (arch.IsValid() && 211 !pos->second->GetArchitecture().IsCompatibleMatch(arch)) 212 match = false; 213 else if (file_offset != LLDB_INVALID_OFFSET && 214 pos->second->GetFileOffset() != file_offset) 215 match = false; 216 if (match) { 217 if (pos->second->GetModificationTime() == time) { 218 return pos->second; 219 } else { 220 // We have a file at the same path with the same architecture whose 221 // modification time doesn't match. It doesn't make sense for us to 222 // continue to use this BSD archive since we cache only the object info 223 // which consists of file time info and also the file offset and file 224 // size of any contained objects. Since this information is now out of 225 // date, we won't get the correct information if we go and extract the 226 // file data, so we should remove the old and outdated entry. 227 archive_map.erase(pos); 228 pos = archive_map.find(file); 229 continue; // Continue to next iteration so we don't increment pos 230 // below... 231 } 232 } 233 ++pos; 234 } 235 return archive_sp; 236 } 237 238 ObjectContainerBSDArchive::Archive::shared_ptr 239 ObjectContainerBSDArchive::Archive::ParseAndCacheArchiveForFile( 240 const FileSpec &file, const ArchSpec &arch, 241 const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset, 242 DataExtractor &data) { 243 shared_ptr archive_sp(new Archive(arch, time, file_offset, data)); 244 if (archive_sp) { 245 const size_t num_objects = archive_sp->ParseObjects(); 246 if (num_objects > 0) { 247 std::lock_guard<std::recursive_mutex> guard( 248 Archive::GetArchiveCacheMutex()); 249 Archive::GetArchiveCache().insert(std::make_pair(file, archive_sp)); 250 } else { 251 archive_sp.reset(); 252 } 253 } 254 return archive_sp; 255 } 256 257 ObjectContainerBSDArchive::Archive::Map & 258 ObjectContainerBSDArchive::Archive::GetArchiveCache() { 259 static Archive::Map g_archive_map; 260 return g_archive_map; 261 } 262 263 std::recursive_mutex & 264 ObjectContainerBSDArchive::Archive::GetArchiveCacheMutex() { 265 static std::recursive_mutex g_archive_map_mutex; 266 return g_archive_map_mutex; 267 } 268 269 void ObjectContainerBSDArchive::Initialize() { 270 PluginManager::RegisterPlugin(GetPluginNameStatic(), 271 GetPluginDescriptionStatic(), CreateInstance, 272 GetModuleSpecifications); 273 } 274 275 void ObjectContainerBSDArchive::Terminate() { 276 PluginManager::UnregisterPlugin(CreateInstance); 277 } 278 279 lldb_private::ConstString ObjectContainerBSDArchive::GetPluginNameStatic() { 280 static ConstString g_name("bsd-archive"); 281 return g_name; 282 } 283 284 const char *ObjectContainerBSDArchive::GetPluginDescriptionStatic() { 285 return "BSD Archive object container reader."; 286 } 287 288 ObjectContainer *ObjectContainerBSDArchive::CreateInstance( 289 const lldb::ModuleSP &module_sp, DataBufferSP &data_sp, 290 lldb::offset_t data_offset, const FileSpec *file, 291 lldb::offset_t file_offset, lldb::offset_t length) { 292 ConstString object_name(module_sp->GetObjectName()); 293 if (!object_name) 294 return nullptr; 295 296 if (data_sp) { 297 // We have data, which means this is the first 512 bytes of the file Check 298 // to see if the magic bytes match and if they do, read the entire table of 299 // contents for the archive and cache it 300 DataExtractor data; 301 data.SetData(data_sp, data_offset, length); 302 if (file && data_sp && ObjectContainerBSDArchive::MagicBytesMatch(data)) { 303 LLDB_SCOPED_TIMERF( 304 "ObjectContainerBSDArchive::CreateInstance (module = %s, file = " 305 "%p, file_offset = 0x%8.8" PRIx64 ", file_size = 0x%8.8" PRIx64 ")", 306 module_sp->GetFileSpec().GetPath().c_str(), 307 static_cast<const void *>(file), static_cast<uint64_t>(file_offset), 308 static_cast<uint64_t>(length)); 309 310 // Map the entire .a file to be sure that we don't lose any data if the 311 // file gets updated by a new build while this .a file is being used for 312 // debugging 313 DataBufferSP archive_data_sp = 314 FileSystem::Instance().CreateDataBuffer(*file, length, file_offset); 315 if (!archive_data_sp) 316 return nullptr; 317 318 lldb::offset_t archive_data_offset = 0; 319 320 Archive::shared_ptr archive_sp(Archive::FindCachedArchive( 321 *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(), 322 file_offset)); 323 std::unique_ptr<ObjectContainerBSDArchive> container_up( 324 new ObjectContainerBSDArchive(module_sp, archive_data_sp, 325 archive_data_offset, file, file_offset, 326 length)); 327 328 if (container_up) { 329 if (archive_sp) { 330 // We already have this archive in our cache, use it 331 container_up->SetArchive(archive_sp); 332 return container_up.release(); 333 } else if (container_up->ParseHeader()) 334 return container_up.release(); 335 } 336 } 337 } else { 338 // No data, just check for a cached archive 339 Archive::shared_ptr archive_sp(Archive::FindCachedArchive( 340 *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(), 341 file_offset)); 342 if (archive_sp) { 343 std::unique_ptr<ObjectContainerBSDArchive> container_up( 344 new ObjectContainerBSDArchive(module_sp, data_sp, data_offset, file, 345 file_offset, length)); 346 347 if (container_up) { 348 // We already have this archive in our cache, use it 349 container_up->SetArchive(archive_sp); 350 return container_up.release(); 351 } 352 } 353 } 354 return nullptr; 355 } 356 357 bool ObjectContainerBSDArchive::MagicBytesMatch(const DataExtractor &data) { 358 uint32_t offset = 0; 359 const char *armag = (const char *)data.PeekData(offset, sizeof(ar_hdr)); 360 if (armag && ::strncmp(armag, ARMAG, SARMAG) == 0) { 361 armag += offsetof(struct ar_hdr, ar_fmag) + SARMAG; 362 if (strncmp(armag, ARFMAG, 2) == 0) 363 return true; 364 } 365 return false; 366 } 367 368 ObjectContainerBSDArchive::ObjectContainerBSDArchive( 369 const lldb::ModuleSP &module_sp, DataBufferSP &data_sp, 370 lldb::offset_t data_offset, const lldb_private::FileSpec *file, 371 lldb::offset_t file_offset, lldb::offset_t size) 372 : ObjectContainer(module_sp, file, file_offset, size, data_sp, data_offset), 373 m_archive_sp() {} 374 void ObjectContainerBSDArchive::SetArchive(Archive::shared_ptr &archive_sp) { 375 m_archive_sp = archive_sp; 376 } 377 378 ObjectContainerBSDArchive::~ObjectContainerBSDArchive() {} 379 380 bool ObjectContainerBSDArchive::ParseHeader() { 381 if (m_archive_sp.get() == nullptr) { 382 if (m_data.GetByteSize() > 0) { 383 ModuleSP module_sp(GetModule()); 384 if (module_sp) { 385 m_archive_sp = Archive::ParseAndCacheArchiveForFile( 386 m_file, module_sp->GetArchitecture(), 387 module_sp->GetModificationTime(), m_offset, m_data); 388 } 389 // Clear the m_data that contains the entire archive data and let our 390 // m_archive_sp hold onto the data. 391 m_data.Clear(); 392 } 393 } 394 return m_archive_sp.get() != nullptr; 395 } 396 397 void ObjectContainerBSDArchive::Dump(Stream *s) const { 398 s->Printf("%p: ", static_cast<const void *>(this)); 399 s->Indent(); 400 const size_t num_archs = GetNumArchitectures(); 401 const size_t num_objects = GetNumObjects(); 402 s->Printf("ObjectContainerBSDArchive, num_archs = %" PRIu64 403 ", num_objects = %" PRIu64 "", 404 (uint64_t)num_archs, (uint64_t)num_objects); 405 uint32_t i; 406 ArchSpec arch; 407 s->IndentMore(); 408 for (i = 0; i < num_archs; i++) { 409 s->Indent(); 410 GetArchitectureAtIndex(i, arch); 411 s->Printf("arch[%u] = %s\n", i, arch.GetArchitectureName()); 412 } 413 for (i = 0; i < num_objects; i++) { 414 s->Indent(); 415 s->Printf("object[%u] = %s\n", i, GetObjectNameAtIndex(i)); 416 } 417 s->IndentLess(); 418 s->EOL(); 419 } 420 421 ObjectFileSP ObjectContainerBSDArchive::GetObjectFile(const FileSpec *file) { 422 ModuleSP module_sp(GetModule()); 423 if (module_sp) { 424 if (module_sp->GetObjectName() && m_archive_sp) { 425 Object *object = m_archive_sp->FindObject( 426 module_sp->GetObjectName(), module_sp->GetObjectModificationTime()); 427 if (object) { 428 lldb::offset_t data_offset = object->file_offset; 429 return ObjectFile::FindPlugin( 430 module_sp, file, m_offset + object->file_offset, object->file_size, 431 m_archive_sp->GetData().GetSharedDataBuffer(), data_offset); 432 } 433 } 434 } 435 return ObjectFileSP(); 436 } 437 438 // PluginInterface protocol 439 lldb_private::ConstString ObjectContainerBSDArchive::GetPluginName() { 440 return GetPluginNameStatic(); 441 } 442 443 uint32_t ObjectContainerBSDArchive::GetPluginVersion() { return 1; } 444 445 size_t ObjectContainerBSDArchive::GetModuleSpecifications( 446 const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp, 447 lldb::offset_t data_offset, lldb::offset_t file_offset, 448 lldb::offset_t file_size, lldb_private::ModuleSpecList &specs) { 449 450 // We have data, which means this is the first 512 bytes of the file Check to 451 // see if the magic bytes match and if they do, read the entire table of 452 // contents for the archive and cache it 453 DataExtractor data; 454 data.SetData(data_sp, data_offset, data_sp->GetByteSize()); 455 if (!file || !data_sp || !ObjectContainerBSDArchive::MagicBytesMatch(data)) 456 return 0; 457 458 const size_t initial_count = specs.GetSize(); 459 llvm::sys::TimePoint<> file_mod_time = FileSystem::Instance().GetModificationTime(file); 460 Archive::shared_ptr archive_sp( 461 Archive::FindCachedArchive(file, ArchSpec(), file_mod_time, file_offset)); 462 bool set_archive_arch = false; 463 if (!archive_sp) { 464 set_archive_arch = true; 465 data_sp = 466 FileSystem::Instance().CreateDataBuffer(file, file_size, file_offset); 467 if (data_sp) { 468 data.SetData(data_sp, 0, data_sp->GetByteSize()); 469 archive_sp = Archive::ParseAndCacheArchiveForFile( 470 file, ArchSpec(), file_mod_time, file_offset, data); 471 } 472 } 473 474 if (archive_sp) { 475 const size_t num_objects = archive_sp->GetNumObjects(); 476 for (size_t idx = 0; idx < num_objects; ++idx) { 477 const Object *object = archive_sp->GetObjectAtIndex(idx); 478 if (object) { 479 const lldb::offset_t object_file_offset = 480 file_offset + object->file_offset; 481 if (object->file_offset < file_size && file_size > object_file_offset) { 482 if (ObjectFile::GetModuleSpecifications( 483 file, object_file_offset, file_size - object_file_offset, 484 specs)) { 485 ModuleSpec &spec = 486 specs.GetModuleSpecRefAtIndex(specs.GetSize() - 1); 487 llvm::sys::TimePoint<> object_mod_time( 488 std::chrono::seconds(object->modification_time)); 489 spec.GetObjectName() = object->ar_name; 490 spec.SetObjectOffset(object_file_offset); 491 spec.SetObjectSize(file_size - object_file_offset); 492 spec.GetObjectModificationTime() = object_mod_time; 493 } 494 } 495 } 496 } 497 } 498 const size_t end_count = specs.GetSize(); 499 size_t num_specs_added = end_count - initial_count; 500 if (set_archive_arch && num_specs_added > 0) { 501 // The archive was created but we didn't have an architecture so we need to 502 // set it 503 for (size_t i = initial_count; i < end_count; ++i) { 504 ModuleSpec module_spec; 505 if (specs.GetModuleSpecAtIndex(i, module_spec)) { 506 if (module_spec.GetArchitecture().IsValid()) { 507 archive_sp->SetArchitecture(module_spec.GetArchitecture()); 508 break; 509 } 510 } 511 } 512 } 513 return num_specs_added; 514 } 515