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