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 17typedef 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 40using namespace lldb; 41using namespace lldb_private; 42 43LLDB_PLUGIN_DEFINE(ObjectContainerBSDArchive) 44 45ObjectContainerBSDArchive::Object::Object() 46 : ar_name(), modification_time(0), uid(0), gid(0), mode(0), size(0), 47 file_offset(0), file_size(0) {} 48 49void 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 60lldb::offset_t 61ObjectContainerBSDArchive::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 138ObjectContainerBSDArchive::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 145ObjectContainerBSDArchive::Archive::~Archive() {} 146 147size_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 172ObjectContainerBSDArchive::Object * 173ObjectContainerBSDArchive::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 198ObjectContainerBSDArchive::Archive::shared_ptr 199ObjectContainerBSDArchive::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 238ObjectContainerBSDArchive::Archive::shared_ptr 239ObjectContainerBSDArchive::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 257ObjectContainerBSDArchive::Archive::Map & 258ObjectContainerBSDArchive::Archive::GetArchiveCache() { 259 static Archive::Map g_archive_map; 260 return g_archive_map; 261} 262 263std::recursive_mutex & 264ObjectContainerBSDArchive::Archive::GetArchiveCacheMutex() { 265 static std::recursive_mutex g_archive_map_mutex; 266 return g_archive_map_mutex; 267} 268 269void ObjectContainerBSDArchive::Initialize() { 270 PluginManager::RegisterPlugin(GetPluginNameStatic(), 271 GetPluginDescriptionStatic(), CreateInstance, 272 GetModuleSpecifications); 273} 274 275void ObjectContainerBSDArchive::Terminate() { 276 PluginManager::UnregisterPlugin(CreateInstance); 277} 278 279lldb_private::ConstString ObjectContainerBSDArchive::GetPluginNameStatic() { 280 static ConstString g_name("bsd-archive"); 281 return g_name; 282} 283 284const char *ObjectContainerBSDArchive::GetPluginDescriptionStatic() { 285 return "BSD Archive object container reader."; 286} 287 288ObjectContainer *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 static Timer::Category func_cat(LLVM_PRETTY_FUNCTION); 304 Timer scoped_timer( 305 func_cat, 306 "ObjectContainerBSDArchive::CreateInstance (module = %s, file = " 307 "%p, file_offset = 0x%8.8" PRIx64 ", file_size = 0x%8.8" PRIx64 ")", 308 module_sp->GetFileSpec().GetPath().c_str(), 309 static_cast<const void *>(file), static_cast<uint64_t>(file_offset), 310 static_cast<uint64_t>(length)); 311 312 // Map the entire .a file to be sure that we don't lose any data if the 313 // file gets updated by a new build while this .a file is being used for 314 // debugging 315 DataBufferSP archive_data_sp = 316 FileSystem::Instance().CreateDataBuffer(*file, length, file_offset); 317 if (!archive_data_sp) 318 return nullptr; 319 320 lldb::offset_t archive_data_offset = 0; 321 322 Archive::shared_ptr archive_sp(Archive::FindCachedArchive( 323 *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(), 324 file_offset)); 325 std::unique_ptr<ObjectContainerBSDArchive> container_up( 326 new ObjectContainerBSDArchive(module_sp, archive_data_sp, 327 archive_data_offset, file, file_offset, 328 length)); 329 330 if (container_up) { 331 if (archive_sp) { 332 // We already have this archive in our cache, use it 333 container_up->SetArchive(archive_sp); 334 return container_up.release(); 335 } else if (container_up->ParseHeader()) 336 return container_up.release(); 337 } 338 } 339 } else { 340 // No data, just check for a cached archive 341 Archive::shared_ptr archive_sp(Archive::FindCachedArchive( 342 *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(), 343 file_offset)); 344 if (archive_sp) { 345 std::unique_ptr<ObjectContainerBSDArchive> container_up( 346 new ObjectContainerBSDArchive(module_sp, data_sp, data_offset, file, 347 file_offset, length)); 348 349 if (container_up) { 350 // We already have this archive in our cache, use it 351 container_up->SetArchive(archive_sp); 352 return container_up.release(); 353 } 354 } 355 } 356 return nullptr; 357} 358 359bool ObjectContainerBSDArchive::MagicBytesMatch(const DataExtractor &data) { 360 uint32_t offset = 0; 361 const char *armag = (const char *)data.PeekData(offset, sizeof(ar_hdr)); 362 if (armag && ::strncmp(armag, ARMAG, SARMAG) == 0) { 363 armag += offsetof(struct ar_hdr, ar_fmag) + SARMAG; 364 if (strncmp(armag, ARFMAG, 2) == 0) 365 return true; 366 } 367 return false; 368} 369 370ObjectContainerBSDArchive::ObjectContainerBSDArchive( 371 const lldb::ModuleSP &module_sp, DataBufferSP &data_sp, 372 lldb::offset_t data_offset, const lldb_private::FileSpec *file, 373 lldb::offset_t file_offset, lldb::offset_t size) 374 : ObjectContainer(module_sp, file, file_offset, size, data_sp, data_offset), 375 m_archive_sp() {} 376void ObjectContainerBSDArchive::SetArchive(Archive::shared_ptr &archive_sp) { 377 m_archive_sp = archive_sp; 378} 379 380ObjectContainerBSDArchive::~ObjectContainerBSDArchive() {} 381 382bool ObjectContainerBSDArchive::ParseHeader() { 383 if (m_archive_sp.get() == nullptr) { 384 if (m_data.GetByteSize() > 0) { 385 ModuleSP module_sp(GetModule()); 386 if (module_sp) { 387 m_archive_sp = Archive::ParseAndCacheArchiveForFile( 388 m_file, module_sp->GetArchitecture(), 389 module_sp->GetModificationTime(), m_offset, m_data); 390 } 391 // Clear the m_data that contains the entire archive data and let our 392 // m_archive_sp hold onto the data. 393 m_data.Clear(); 394 } 395 } 396 return m_archive_sp.get() != nullptr; 397} 398 399void ObjectContainerBSDArchive::Dump(Stream *s) const { 400 s->Printf("%p: ", static_cast<const void *>(this)); 401 s->Indent(); 402 const size_t num_archs = GetNumArchitectures(); 403 const size_t num_objects = GetNumObjects(); 404 s->Printf("ObjectContainerBSDArchive, num_archs = %" PRIu64 405 ", num_objects = %" PRIu64 "", 406 (uint64_t)num_archs, (uint64_t)num_objects); 407 uint32_t i; 408 ArchSpec arch; 409 s->IndentMore(); 410 for (i = 0; i < num_archs; i++) { 411 s->Indent(); 412 GetArchitectureAtIndex(i, arch); 413 s->Printf("arch[%u] = %s\n", i, arch.GetArchitectureName()); 414 } 415 for (i = 0; i < num_objects; i++) { 416 s->Indent(); 417 s->Printf("object[%u] = %s\n", i, GetObjectNameAtIndex(i)); 418 } 419 s->IndentLess(); 420 s->EOL(); 421} 422 423ObjectFileSP ObjectContainerBSDArchive::GetObjectFile(const FileSpec *file) { 424 ModuleSP module_sp(GetModule()); 425 if (module_sp) { 426 if (module_sp->GetObjectName() && m_archive_sp) { 427 Object *object = m_archive_sp->FindObject( 428 module_sp->GetObjectName(), module_sp->GetObjectModificationTime()); 429 if (object) { 430 lldb::offset_t data_offset = object->file_offset; 431 return ObjectFile::FindPlugin( 432 module_sp, file, m_offset + object->file_offset, object->file_size, 433 m_archive_sp->GetData().GetSharedDataBuffer(), data_offset); 434 } 435 } 436 } 437 return ObjectFileSP(); 438} 439 440// PluginInterface protocol 441lldb_private::ConstString ObjectContainerBSDArchive::GetPluginName() { 442 return GetPluginNameStatic(); 443} 444 445uint32_t ObjectContainerBSDArchive::GetPluginVersion() { return 1; } 446 447size_t ObjectContainerBSDArchive::GetModuleSpecifications( 448 const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp, 449 lldb::offset_t data_offset, lldb::offset_t file_offset, 450 lldb::offset_t file_size, lldb_private::ModuleSpecList &specs) { 451 452 // We have data, which means this is the first 512 bytes of the file Check to 453 // see if the magic bytes match and if they do, read the entire table of 454 // contents for the archive and cache it 455 DataExtractor data; 456 data.SetData(data_sp, data_offset, data_sp->GetByteSize()); 457 if (!file || !data_sp || !ObjectContainerBSDArchive::MagicBytesMatch(data)) 458 return 0; 459 460 const size_t initial_count = specs.GetSize(); 461 llvm::sys::TimePoint<> file_mod_time = FileSystem::Instance().GetModificationTime(file); 462 Archive::shared_ptr archive_sp( 463 Archive::FindCachedArchive(file, ArchSpec(), file_mod_time, file_offset)); 464 bool set_archive_arch = false; 465 if (!archive_sp) { 466 set_archive_arch = true; 467 data_sp = 468 FileSystem::Instance().CreateDataBuffer(file, file_size, file_offset); 469 if (data_sp) { 470 data.SetData(data_sp, 0, data_sp->GetByteSize()); 471 archive_sp = Archive::ParseAndCacheArchiveForFile( 472 file, ArchSpec(), file_mod_time, file_offset, data); 473 } 474 } 475 476 if (archive_sp) { 477 const size_t num_objects = archive_sp->GetNumObjects(); 478 for (size_t idx = 0; idx < num_objects; ++idx) { 479 const Object *object = archive_sp->GetObjectAtIndex(idx); 480 if (object) { 481 const lldb::offset_t object_file_offset = 482 file_offset + object->file_offset; 483 if (object->file_offset < file_size && file_size > object_file_offset) { 484 if (ObjectFile::GetModuleSpecifications( 485 file, object_file_offset, file_size - object_file_offset, 486 specs)) { 487 ModuleSpec &spec = 488 specs.GetModuleSpecRefAtIndex(specs.GetSize() - 1); 489 llvm::sys::TimePoint<> object_mod_time( 490 std::chrono::seconds(object->modification_time)); 491 spec.GetObjectName() = object->ar_name; 492 spec.SetObjectOffset(object_file_offset); 493 spec.SetObjectSize(file_size - object_file_offset); 494 spec.GetObjectModificationTime() = object_mod_time; 495 } 496 } 497 } 498 } 499 } 500 const size_t end_count = specs.GetSize(); 501 size_t num_specs_added = end_count - initial_count; 502 if (set_archive_arch && num_specs_added > 0) { 503 // The archive was created but we didn't have an architecture so we need to 504 // set it 505 for (size_t i = initial_count; i < end_count; ++i) { 506 ModuleSpec module_spec; 507 if (specs.GetModuleSpecAtIndex(i, module_spec)) { 508 if (module_spec.GetArchitecture().IsValid()) { 509 archive_sp->SetArchitecture(module_spec.GetArchitecture()); 510 break; 511 } 512 } 513 } 514 } 515 return num_specs_added; 516} 517