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 SARMAG 8 14 #define ARFMAG "`\n" 15 16 typedef struct ar_hdr { 17 char ar_name[16]; 18 char ar_date[12]; 19 char ar_uid[6], ar_gid[6]; 20 char ar_mode[8]; 21 char ar_size[10]; 22 char ar_fmag[2]; 23 } ar_hdr; 24 #else 25 #include <ar.h> 26 #endif 27 28 #include "lldb/Core/Module.h" 29 #include "lldb/Core/ModuleSpec.h" 30 #include "lldb/Core/PluginManager.h" 31 #include "lldb/Host/FileSystem.h" 32 #include "lldb/Symbol/ObjectFile.h" 33 #include "lldb/Utility/ArchSpec.h" 34 #include "lldb/Utility/LLDBLog.h" 35 #include "lldb/Utility/Stream.h" 36 #include "lldb/Utility/Timer.h" 37 38 #include "llvm/Object/Archive.h" 39 #include "llvm/Support/MemoryBuffer.h" 40 41 using namespace lldb; 42 using namespace lldb_private; 43 44 using namespace llvm::object; 45 46 LLDB_PLUGIN_DEFINE(ObjectContainerBSDArchive) 47 48 ObjectContainerBSDArchive::Object::Object() : ar_name() {} 49 50 void ObjectContainerBSDArchive::Object::Clear() { 51 ar_name.Clear(); 52 modification_time = 0; 53 size = 0; 54 file_offset = 0; 55 file_size = 0; 56 } 57 58 void ObjectContainerBSDArchive::Object::Dump() const { 59 printf("name = \"%s\"\n", ar_name.GetCString()); 60 printf("mtime = 0x%8.8" PRIx32 "\n", modification_time); 61 printf("size = 0x%8.8" PRIx32 " (%" PRIu32 ")\n", size, size); 62 printf("file_offset = 0x%16.16" PRIx64 " (%" PRIu64 ")\n", file_offset, 63 file_offset); 64 printf("file_size = 0x%16.16" PRIx64 " (%" PRIu64 ")\n\n", file_size, 65 file_size); 66 } 67 68 ObjectContainerBSDArchive::Archive::Archive(const lldb_private::ArchSpec &arch, 69 const llvm::sys::TimePoint<> &time, 70 lldb::offset_t file_offset, 71 lldb_private::DataExtractor &data, 72 ArchiveType archive_type) 73 : m_arch(arch), m_modification_time(time), m_file_offset(file_offset), 74 m_objects(), m_data(data), m_archive_type(archive_type) {} 75 76 Log *l = GetLog(LLDBLog::Object); 77 ObjectContainerBSDArchive::Archive::~Archive() = default; 78 79 size_t ObjectContainerBSDArchive::Archive::ParseObjects() { 80 DataExtractor &data = m_data; 81 82 std::unique_ptr<llvm::MemoryBuffer> mem_buffer = 83 llvm::MemoryBuffer::getMemBuffer( 84 llvm::StringRef((const char *)data.GetDataStart(), 85 data.GetByteSize()), 86 llvm::StringRef(), 87 /*RequiresNullTerminator=*/false); 88 89 auto exp_ar = llvm::object::Archive::create(mem_buffer->getMemBufferRef()); 90 if (!exp_ar) { 91 LLDB_LOG_ERROR(l, exp_ar.takeError(), "failed to create archive: {0}"); 92 return 0; 93 } 94 auto llvm_archive = std::move(exp_ar.get()); 95 96 llvm::Error iter_err = llvm::Error::success(); 97 Object obj; 98 for (const auto &child: llvm_archive->children(iter_err)) { 99 obj.Clear(); 100 auto exp_name = child.getName(); 101 if (exp_name) { 102 obj.ar_name = ConstString(exp_name.get()); 103 } else { 104 LLDB_LOG_ERROR(l, exp_name.takeError(), 105 "failed to get archive object name: {0}"); 106 continue; 107 } 108 109 auto exp_mtime = child.getLastModified(); 110 if (exp_mtime) { 111 obj.modification_time = 112 std::chrono::duration_cast<std::chrono::seconds>( 113 std::chrono::time_point_cast<std::chrono::seconds>( 114 exp_mtime.get()).time_since_epoch()).count(); 115 } else { 116 LLDB_LOG_ERROR(l, exp_mtime.takeError(), 117 "failed to get archive object time: {0}"); 118 continue; 119 } 120 121 auto exp_size = child.getRawSize(); 122 if (exp_size) { 123 obj.size = exp_size.get(); 124 } else { 125 LLDB_LOG_ERROR(l, exp_size.takeError(), 126 "failed to get archive object size: {0}"); 127 continue; 128 } 129 130 obj.file_offset = child.getDataOffset(); 131 132 auto exp_file_size = child.getSize(); 133 if (exp_file_size) { 134 obj.file_size = exp_file_size.get(); 135 } else { 136 LLDB_LOG_ERROR(l, exp_file_size.takeError(), 137 "failed to get archive object file size: {0}"); 138 continue; 139 } 140 m_object_name_to_index_map.Append(obj.ar_name, m_objects.size()); 141 m_objects.push_back(obj); 142 } 143 if (iter_err) { 144 LLDB_LOG_ERROR(l, std::move(iter_err), 145 "failed to iterate over archive objects: {0}"); 146 } 147 // Now sort all of the object name pointers 148 m_object_name_to_index_map.Sort(); 149 return m_objects.size(); 150 } 151 152 ObjectContainerBSDArchive::Object * 153 ObjectContainerBSDArchive::Archive::FindObject( 154 ConstString object_name, const llvm::sys::TimePoint<> &object_mod_time) { 155 const ObjectNameToIndexMap::Entry *match = 156 m_object_name_to_index_map.FindFirstValueForName(object_name); 157 if (!match) 158 return nullptr; 159 if (object_mod_time == llvm::sys::TimePoint<>()) 160 return &m_objects[match->value]; 161 162 const uint64_t object_modification_date = llvm::sys::toTimeT(object_mod_time); 163 if (m_objects[match->value].modification_time == object_modification_date) 164 return &m_objects[match->value]; 165 166 const ObjectNameToIndexMap::Entry *next_match = 167 m_object_name_to_index_map.FindNextValueForName(match); 168 while (next_match) { 169 if (m_objects[next_match->value].modification_time == 170 object_modification_date) 171 return &m_objects[next_match->value]; 172 next_match = m_object_name_to_index_map.FindNextValueForName(next_match); 173 } 174 175 return nullptr; 176 } 177 178 ObjectContainerBSDArchive::Archive::shared_ptr 179 ObjectContainerBSDArchive::Archive::FindCachedArchive( 180 const FileSpec &file, const ArchSpec &arch, 181 const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset) { 182 std::lock_guard<std::recursive_mutex> guard(Archive::GetArchiveCacheMutex()); 183 shared_ptr archive_sp; 184 Archive::Map &archive_map = Archive::GetArchiveCache(); 185 Archive::Map::iterator pos = archive_map.find(file); 186 // Don't cache a value for "archive_map.end()" below since we might delete an 187 // archive entry... 188 while (pos != archive_map.end() && pos->first == file) { 189 bool match = true; 190 if (arch.IsValid() && 191 !pos->second->GetArchitecture().IsCompatibleMatch(arch)) 192 match = false; 193 else if (file_offset != LLDB_INVALID_OFFSET && 194 pos->second->GetFileOffset() != file_offset) 195 match = false; 196 if (match) { 197 if (pos->second->GetModificationTime() == time) { 198 return pos->second; 199 } else { 200 // We have a file at the same path with the same architecture whose 201 // modification time doesn't match. It doesn't make sense for us to 202 // continue to use this BSD archive since we cache only the object info 203 // which consists of file time info and also the file offset and file 204 // size of any contained objects. Since this information is now out of 205 // date, we won't get the correct information if we go and extract the 206 // file data, so we should remove the old and outdated entry. 207 archive_map.erase(pos); 208 pos = archive_map.find(file); 209 continue; // Continue to next iteration so we don't increment pos 210 // below... 211 } 212 } 213 ++pos; 214 } 215 return archive_sp; 216 } 217 218 ObjectContainerBSDArchive::Archive::shared_ptr 219 ObjectContainerBSDArchive::Archive::ParseAndCacheArchiveForFile( 220 const FileSpec &file, const ArchSpec &arch, 221 const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset, 222 DataExtractor &data, ArchiveType archive_type) { 223 shared_ptr archive_sp( 224 new Archive(arch, time, file_offset, data, archive_type)); 225 if (archive_sp) { 226 const size_t num_objects = archive_sp->ParseObjects(); 227 if (num_objects > 0) { 228 std::lock_guard<std::recursive_mutex> guard( 229 Archive::GetArchiveCacheMutex()); 230 Archive::GetArchiveCache().insert(std::make_pair(file, archive_sp)); 231 } else { 232 archive_sp.reset(); 233 } 234 } 235 return archive_sp; 236 } 237 238 ObjectContainerBSDArchive::Archive::Map & 239 ObjectContainerBSDArchive::Archive::GetArchiveCache() { 240 static Archive::Map g_archive_map; 241 return g_archive_map; 242 } 243 244 std::recursive_mutex & 245 ObjectContainerBSDArchive::Archive::GetArchiveCacheMutex() { 246 static std::recursive_mutex g_archive_map_mutex; 247 return g_archive_map_mutex; 248 } 249 250 void ObjectContainerBSDArchive::Initialize() { 251 PluginManager::RegisterPlugin(GetPluginNameStatic(), 252 GetPluginDescriptionStatic(), CreateInstance, 253 GetModuleSpecifications); 254 } 255 256 void ObjectContainerBSDArchive::Terminate() { 257 PluginManager::UnregisterPlugin(CreateInstance); 258 } 259 260 ObjectContainer *ObjectContainerBSDArchive::CreateInstance( 261 const lldb::ModuleSP &module_sp, DataBufferSP &data_sp, 262 lldb::offset_t data_offset, const FileSpec *file, 263 lldb::offset_t file_offset, lldb::offset_t length) { 264 ConstString object_name(module_sp->GetObjectName()); 265 if (!object_name) 266 return nullptr; 267 268 if (data_sp) { 269 // We have data, which means this is the first 512 bytes of the file Check 270 // to see if the magic bytes match and if they do, read the entire table of 271 // contents for the archive and cache it 272 DataExtractor data; 273 data.SetData(data_sp, data_offset, length); 274 ArchiveType archive_type = ObjectContainerBSDArchive::MagicBytesMatch(data); 275 if (file && data_sp && archive_type != ArchiveType::Invalid) { 276 LLDB_SCOPED_TIMERF( 277 "ObjectContainerBSDArchive::CreateInstance (module = %s, file = " 278 "%p, file_offset = 0x%8.8" PRIx64 ", file_size = 0x%8.8" PRIx64 ")", 279 module_sp->GetFileSpec().GetPath().c_str(), 280 static_cast<const void *>(file), static_cast<uint64_t>(file_offset), 281 static_cast<uint64_t>(length)); 282 283 // Map the entire .a file to be sure that we don't lose any data if the 284 // file gets updated by a new build while this .a file is being used for 285 // debugging 286 DataBufferSP archive_data_sp = 287 FileSystem::Instance().CreateDataBuffer(*file, length, file_offset); 288 if (!archive_data_sp) 289 return nullptr; 290 291 lldb::offset_t archive_data_offset = 0; 292 293 Archive::shared_ptr archive_sp(Archive::FindCachedArchive( 294 *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(), 295 file_offset)); 296 std::unique_ptr<ObjectContainerBSDArchive> container_up( 297 new ObjectContainerBSDArchive(module_sp, archive_data_sp, 298 archive_data_offset, file, file_offset, 299 length, archive_type)); 300 301 if (container_up) { 302 if (archive_sp) { 303 // We already have this archive in our cache, use it 304 container_up->SetArchive(archive_sp); 305 return container_up.release(); 306 } else if (container_up->ParseHeader()) 307 return container_up.release(); 308 } 309 } 310 } else { 311 // No data, just check for a cached archive 312 Archive::shared_ptr archive_sp(Archive::FindCachedArchive( 313 *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(), 314 file_offset)); 315 if (archive_sp) { 316 std::unique_ptr<ObjectContainerBSDArchive> container_up( 317 new ObjectContainerBSDArchive(module_sp, data_sp, data_offset, file, 318 file_offset, length, 319 archive_sp->GetArchiveType())); 320 321 if (container_up) { 322 // We already have this archive in our cache, use it 323 container_up->SetArchive(archive_sp); 324 return container_up.release(); 325 } 326 } 327 } 328 return nullptr; 329 } 330 331 ArchiveType 332 ObjectContainerBSDArchive::MagicBytesMatch(const DataExtractor &data) { 333 uint32_t offset = 0; 334 const char *armag = (const char *)data.PeekData(offset, 335 sizeof(ar_hdr) + SARMAG); 336 if (armag == nullptr) 337 return ArchiveType::Invalid; 338 ArchiveType result = ArchiveType::Invalid; 339 if (strncmp(armag, ArchiveMagic, SARMAG) == 0) 340 result = ArchiveType::Archive; 341 else if (strncmp(armag, ThinArchiveMagic, SARMAG) == 0) 342 result = ArchiveType::ThinArchive; 343 else 344 return ArchiveType::Invalid; 345 346 armag += offsetof(struct ar_hdr, ar_fmag) + SARMAG; 347 if (strncmp(armag, ARFMAG, 2) == 0) 348 return result; 349 return ArchiveType::Invalid; 350 } 351 352 ObjectContainerBSDArchive::ObjectContainerBSDArchive( 353 const lldb::ModuleSP &module_sp, DataBufferSP &data_sp, 354 lldb::offset_t data_offset, const lldb_private::FileSpec *file, 355 lldb::offset_t file_offset, lldb::offset_t size, ArchiveType archive_type) 356 : ObjectContainer(module_sp, file, file_offset, size, data_sp, data_offset), 357 m_archive_sp() { 358 m_archive_type = archive_type; 359 } 360 361 void ObjectContainerBSDArchive::SetArchive(Archive::shared_ptr &archive_sp) { 362 m_archive_sp = archive_sp; 363 } 364 365 ObjectContainerBSDArchive::~ObjectContainerBSDArchive() = default; 366 367 bool ObjectContainerBSDArchive::ParseHeader() { 368 if (m_archive_sp.get() == nullptr) { 369 if (m_data.GetByteSize() > 0) { 370 ModuleSP module_sp(GetModule()); 371 if (module_sp) { 372 m_archive_sp = Archive::ParseAndCacheArchiveForFile( 373 m_file, module_sp->GetArchitecture(), 374 module_sp->GetModificationTime(), m_offset, m_data, m_archive_type); 375 } 376 // Clear the m_data that contains the entire archive data and let our 377 // m_archive_sp hold onto the data. 378 m_data.Clear(); 379 } 380 } 381 return m_archive_sp.get() != nullptr; 382 } 383 384 FileSpec GetChildFileSpecificationsFromThin(llvm::StringRef childPath, 385 const FileSpec &parentFileSpec) { 386 llvm::SmallString<128> FullPath; 387 if (llvm::sys::path::is_absolute(childPath)) { 388 FullPath = childPath; 389 } else { 390 FullPath = parentFileSpec.GetDirectory().GetStringRef(); 391 llvm::sys::path::append(FullPath, childPath); 392 } 393 FileSpec child = FileSpec(FullPath.str(), llvm::sys::path::Style::posix); 394 return child; 395 } 396 397 ObjectFileSP ObjectContainerBSDArchive::GetObjectFile(const FileSpec *file) { 398 ModuleSP module_sp(GetModule()); 399 if (module_sp) { 400 if (module_sp->GetObjectName() && m_archive_sp) { 401 Object *object = m_archive_sp->FindObject( 402 module_sp->GetObjectName(), module_sp->GetObjectModificationTime()); 403 if (object) { 404 if (m_archive_type == ArchiveType::ThinArchive) { 405 // Set file to child object file 406 FileSpec child = GetChildFileSpecificationsFromThin( 407 object->ar_name.GetStringRef(), m_file); 408 lldb::offset_t file_offset = 0; 409 lldb::offset_t file_size = object->size; 410 std::shared_ptr<DataBuffer> child_data_sp = 411 FileSystem::Instance().CreateDataBuffer(child, file_size, 412 file_offset); 413 if (!child_data_sp || 414 child_data_sp->GetByteSize() != object->file_size) 415 return ObjectFileSP(); 416 lldb::offset_t data_offset = 0; 417 return ObjectFile::FindPlugin( 418 module_sp, &child, m_offset + object->file_offset, 419 object->file_size, child_data_sp, data_offset); 420 } 421 lldb::offset_t data_offset = object->file_offset; 422 return ObjectFile::FindPlugin( 423 module_sp, file, m_offset + object->file_offset, object->file_size, 424 m_archive_sp->GetData().GetSharedDataBuffer(), data_offset); 425 } 426 } 427 } 428 return ObjectFileSP(); 429 } 430 431 size_t ObjectContainerBSDArchive::GetModuleSpecifications( 432 const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp, 433 lldb::offset_t data_offset, lldb::offset_t file_offset, 434 lldb::offset_t file_size, lldb_private::ModuleSpecList &specs) { 435 436 // We have data, which means this is the first 512 bytes of the file Check to 437 // see if the magic bytes match and if they do, read the entire table of 438 // contents for the archive and cache it 439 DataExtractor data; 440 data.SetData(data_sp, data_offset, data_sp->GetByteSize()); 441 ArchiveType archive_type = ObjectContainerBSDArchive::MagicBytesMatch(data); 442 if (!file || !data_sp || archive_type == ArchiveType::Invalid) 443 return 0; 444 445 const size_t initial_count = specs.GetSize(); 446 llvm::sys::TimePoint<> file_mod_time = FileSystem::Instance().GetModificationTime(file); 447 Archive::shared_ptr archive_sp( 448 Archive::FindCachedArchive(file, ArchSpec(), file_mod_time, file_offset)); 449 bool set_archive_arch = false; 450 if (!archive_sp) { 451 set_archive_arch = true; 452 data_sp = 453 FileSystem::Instance().CreateDataBuffer(file, file_size, file_offset); 454 if (data_sp) { 455 data.SetData(data_sp, 0, data_sp->GetByteSize()); 456 archive_sp = Archive::ParseAndCacheArchiveForFile( 457 file, ArchSpec(), file_mod_time, file_offset, data, archive_type); 458 } 459 } 460 461 if (archive_sp) { 462 const size_t num_objects = archive_sp->GetNumObjects(); 463 for (size_t idx = 0; idx < num_objects; ++idx) { 464 const Object *object = archive_sp->GetObjectAtIndex(idx); 465 if (object) { 466 if (archive_sp->GetArchiveType() == ArchiveType::ThinArchive) { 467 if (object->ar_name.IsEmpty()) 468 continue; 469 FileSpec child = GetChildFileSpecificationsFromThin( 470 object->ar_name.GetStringRef(), file); 471 if (ObjectFile::GetModuleSpecifications(child, 0, object->file_size, 472 specs)) { 473 ModuleSpec &spec = 474 specs.GetModuleSpecRefAtIndex(specs.GetSize() - 1); 475 llvm::sys::TimePoint<> object_mod_time( 476 std::chrono::seconds(object->modification_time)); 477 spec.GetObjectName() = object->ar_name; 478 spec.SetObjectOffset(0); 479 spec.SetObjectSize(object->file_size); 480 spec.GetObjectModificationTime() = object_mod_time; 481 } 482 continue; 483 } 484 const lldb::offset_t object_file_offset = 485 file_offset + object->file_offset; 486 if (object->file_offset < file_size && file_size > object_file_offset) { 487 if (ObjectFile::GetModuleSpecifications( 488 file, object_file_offset, file_size - object_file_offset, 489 specs)) { 490 ModuleSpec &spec = 491 specs.GetModuleSpecRefAtIndex(specs.GetSize() - 1); 492 llvm::sys::TimePoint<> object_mod_time( 493 std::chrono::seconds(object->modification_time)); 494 spec.GetObjectName() = object->ar_name; 495 spec.SetObjectOffset(object_file_offset); 496 spec.SetObjectSize(object->file_size); 497 spec.GetObjectModificationTime() = object_mod_time; 498 } 499 } 500 } 501 } 502 } 503 const size_t end_count = specs.GetSize(); 504 size_t num_specs_added = end_count - initial_count; 505 if (set_archive_arch && num_specs_added > 0) { 506 // The archive was created but we didn't have an architecture so we need to 507 // set it 508 for (size_t i = initial_count; i < end_count; ++i) { 509 ModuleSpec module_spec; 510 if (specs.GetModuleSpecAtIndex(i, module_spec)) { 511 if (module_spec.GetArchitecture().IsValid()) { 512 archive_sp->SetArchitecture(module_spec.GetArchitecture()); 513 break; 514 } 515 } 516 } 517 } 518 return num_specs_added; 519 } 520