//===-- ObjectContainerBSDArchive.cpp -------------------------------------===// // // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // See https://llvm.org/LICENSE.txt for license information. // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // //===----------------------------------------------------------------------===// #include "ObjectContainerBSDArchive.h" #if defined(_WIN32) || defined(__ANDROID__) // Defines from ar, missing on Windows #define ARMAG "!\n" #define SARMAG 8 #define ARFMAG "`\n" typedef struct ar_hdr { char ar_name[16]; char ar_date[12]; char ar_uid[6], ar_gid[6]; char ar_mode[8]; char ar_size[10]; char ar_fmag[2]; } ar_hdr; #else #include #endif #include "lldb/Core/Module.h" #include "lldb/Core/ModuleSpec.h" #include "lldb/Core/PluginManager.h" #include "lldb/Host/FileSystem.h" #include "lldb/Symbol/ObjectFile.h" #include "lldb/Utility/ArchSpec.h" #include "lldb/Utility/Stream.h" #include "lldb/Utility/Timer.h" #include "llvm/Support/MemoryBuffer.h" using namespace lldb; using namespace lldb_private; LLDB_PLUGIN_DEFINE(ObjectContainerBSDArchive) ObjectContainerBSDArchive::Object::Object() : ar_name(), modification_time(0), uid(0), gid(0), mode(0), size(0), file_offset(0), file_size(0) {} void ObjectContainerBSDArchive::Object::Clear() { ar_name.Clear(); modification_time = 0; uid = 0; gid = 0; mode = 0; size = 0; file_offset = 0; file_size = 0; } lldb::offset_t ObjectContainerBSDArchive::Object::Extract(const DataExtractor &data, lldb::offset_t offset) { size_t ar_name_len = 0; std::string str; char *err; // File header // // The common format is as follows. // // Offset Length Name Format // 0 16 File name ASCII right padded with spaces (no spaces // allowed in file name) // 16 12 File mod Decimal as cstring right padded with // spaces // 28 6 Owner ID Decimal as cstring right padded with // spaces // 34 6 Group ID Decimal as cstring right padded with // spaces // 40 8 File mode Octal as cstring right padded with // spaces // 48 10 File byte size Decimal as cstring right padded with // spaces // 58 2 File magic 0x60 0x0A // Make sure there is enough data for the file header and bail if not if (!data.ValidOffsetForDataOfSize(offset, 60)) return LLDB_INVALID_OFFSET; str.assign((const char *)data.GetData(&offset, 16), 16); if (llvm::StringRef(str).startswith("#1/")) { // If the name is longer than 16 bytes, or contains an embedded space then // it will use this format where the length of the name is here and the // name characters are after this header. ar_name_len = strtoul(str.c_str() + 3, &err, 10); } else { // Strip off any trailing spaces. const size_t last_pos = str.find_last_not_of(' '); if (last_pos != std::string::npos) { if (last_pos + 1 < 16) str.erase(last_pos + 1); } ar_name.SetCString(str.c_str()); } str.assign((const char *)data.GetData(&offset, 12), 12); modification_time = strtoul(str.c_str(), &err, 10); str.assign((const char *)data.GetData(&offset, 6), 6); uid = strtoul(str.c_str(), &err, 10); str.assign((const char *)data.GetData(&offset, 6), 6); gid = strtoul(str.c_str(), &err, 10); str.assign((const char *)data.GetData(&offset, 8), 8); mode = strtoul(str.c_str(), &err, 8); str.assign((const char *)data.GetData(&offset, 10), 10); size = strtoul(str.c_str(), &err, 10); str.assign((const char *)data.GetData(&offset, 2), 2); if (str == ARFMAG) { if (ar_name_len > 0) { const void *ar_name_ptr = data.GetData(&offset, ar_name_len); // Make sure there was enough data for the string value and bail if not if (ar_name_ptr == nullptr) return LLDB_INVALID_OFFSET; str.assign((const char *)ar_name_ptr, ar_name_len); ar_name.SetCString(str.c_str()); } file_offset = offset; file_size = size - ar_name_len; return offset; } return LLDB_INVALID_OFFSET; } ObjectContainerBSDArchive::Archive::Archive(const lldb_private::ArchSpec &arch, const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset, lldb_private::DataExtractor &data) : m_arch(arch), m_modification_time(time), m_file_offset(file_offset), m_objects(), m_data(data) {} ObjectContainerBSDArchive::Archive::~Archive() {} size_t ObjectContainerBSDArchive::Archive::ParseObjects() { DataExtractor &data = m_data; std::string str; lldb::offset_t offset = 0; str.assign((const char *)data.GetData(&offset, SARMAG), SARMAG); if (str == ARMAG) { Object obj; do { offset = obj.Extract(data, offset); if (offset == LLDB_INVALID_OFFSET) break; size_t obj_idx = m_objects.size(); m_objects.push_back(obj); // Insert all of the C strings out of order for now... m_object_name_to_index_map.Append(obj.ar_name, obj_idx); offset += obj.file_size; obj.Clear(); } while (data.ValidOffset(offset)); // Now sort all of the object name pointers m_object_name_to_index_map.Sort(); } return m_objects.size(); } ObjectContainerBSDArchive::Object * ObjectContainerBSDArchive::Archive::FindObject( ConstString object_name, const llvm::sys::TimePoint<> &object_mod_time) { const ObjectNameToIndexMap::Entry *match = m_object_name_to_index_map.FindFirstValueForName(object_name); if (!match) return nullptr; if (object_mod_time == llvm::sys::TimePoint<>()) return &m_objects[match->value]; const uint64_t object_modification_date = llvm::sys::toTimeT(object_mod_time); if (m_objects[match->value].modification_time == object_modification_date) return &m_objects[match->value]; const ObjectNameToIndexMap::Entry *next_match = m_object_name_to_index_map.FindNextValueForName(match); while (next_match) { if (m_objects[next_match->value].modification_time == object_modification_date) return &m_objects[next_match->value]; next_match = m_object_name_to_index_map.FindNextValueForName(next_match); } return nullptr; } ObjectContainerBSDArchive::Archive::shared_ptr ObjectContainerBSDArchive::Archive::FindCachedArchive( const FileSpec &file, const ArchSpec &arch, const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset) { std::lock_guard guard(Archive::GetArchiveCacheMutex()); shared_ptr archive_sp; Archive::Map &archive_map = Archive::GetArchiveCache(); Archive::Map::iterator pos = archive_map.find(file); // Don't cache a value for "archive_map.end()" below since we might delete an // archive entry... while (pos != archive_map.end() && pos->first == file) { bool match = true; if (arch.IsValid() && !pos->second->GetArchitecture().IsCompatibleMatch(arch)) match = false; else if (file_offset != LLDB_INVALID_OFFSET && pos->second->GetFileOffset() != file_offset) match = false; if (match) { if (pos->second->GetModificationTime() == time) { return pos->second; } else { // We have a file at the same path with the same architecture whose // modification time doesn't match. It doesn't make sense for us to // continue to use this BSD archive since we cache only the object info // which consists of file time info and also the file offset and file // size of any contained objects. Since this information is now out of // date, we won't get the correct information if we go and extract the // file data, so we should remove the old and outdated entry. archive_map.erase(pos); pos = archive_map.find(file); continue; // Continue to next iteration so we don't increment pos // below... } } ++pos; } return archive_sp; } ObjectContainerBSDArchive::Archive::shared_ptr ObjectContainerBSDArchive::Archive::ParseAndCacheArchiveForFile( const FileSpec &file, const ArchSpec &arch, const llvm::sys::TimePoint<> &time, lldb::offset_t file_offset, DataExtractor &data) { shared_ptr archive_sp(new Archive(arch, time, file_offset, data)); if (archive_sp) { const size_t num_objects = archive_sp->ParseObjects(); if (num_objects > 0) { std::lock_guard guard( Archive::GetArchiveCacheMutex()); Archive::GetArchiveCache().insert(std::make_pair(file, archive_sp)); } else { archive_sp.reset(); } } return archive_sp; } ObjectContainerBSDArchive::Archive::Map & ObjectContainerBSDArchive::Archive::GetArchiveCache() { static Archive::Map g_archive_map; return g_archive_map; } std::recursive_mutex & ObjectContainerBSDArchive::Archive::GetArchiveCacheMutex() { static std::recursive_mutex g_archive_map_mutex; return g_archive_map_mutex; } void ObjectContainerBSDArchive::Initialize() { PluginManager::RegisterPlugin(GetPluginNameStatic(), GetPluginDescriptionStatic(), CreateInstance, GetModuleSpecifications); } void ObjectContainerBSDArchive::Terminate() { PluginManager::UnregisterPlugin(CreateInstance); } lldb_private::ConstString ObjectContainerBSDArchive::GetPluginNameStatic() { static ConstString g_name("bsd-archive"); return g_name; } const char *ObjectContainerBSDArchive::GetPluginDescriptionStatic() { return "BSD Archive object container reader."; } ObjectContainer *ObjectContainerBSDArchive::CreateInstance( const lldb::ModuleSP &module_sp, DataBufferSP &data_sp, lldb::offset_t data_offset, const FileSpec *file, lldb::offset_t file_offset, lldb::offset_t length) { ConstString object_name(module_sp->GetObjectName()); if (!object_name) return nullptr; if (data_sp) { // We have data, which means this is the first 512 bytes of the file Check // to see if the magic bytes match and if they do, read the entire table of // contents for the archive and cache it DataExtractor data; data.SetData(data_sp, data_offset, length); if (file && data_sp && ObjectContainerBSDArchive::MagicBytesMatch(data)) { static Timer::Category func_cat(LLVM_PRETTY_FUNCTION); Timer scoped_timer( func_cat, "ObjectContainerBSDArchive::CreateInstance (module = %s, file = " "%p, file_offset = 0x%8.8" PRIx64 ", file_size = 0x%8.8" PRIx64 ")", module_sp->GetFileSpec().GetPath().c_str(), static_cast(file), static_cast(file_offset), static_cast(length)); // Map the entire .a file to be sure that we don't lose any data if the // file gets updated by a new build while this .a file is being used for // debugging DataBufferSP archive_data_sp = FileSystem::Instance().CreateDataBuffer(*file, length, file_offset); if (!archive_data_sp) return nullptr; lldb::offset_t archive_data_offset = 0; Archive::shared_ptr archive_sp(Archive::FindCachedArchive( *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(), file_offset)); std::unique_ptr container_up( new ObjectContainerBSDArchive(module_sp, archive_data_sp, archive_data_offset, file, file_offset, length)); if (container_up) { if (archive_sp) { // We already have this archive in our cache, use it container_up->SetArchive(archive_sp); return container_up.release(); } else if (container_up->ParseHeader()) return container_up.release(); } } } else { // No data, just check for a cached archive Archive::shared_ptr archive_sp(Archive::FindCachedArchive( *file, module_sp->GetArchitecture(), module_sp->GetModificationTime(), file_offset)); if (archive_sp) { std::unique_ptr container_up( new ObjectContainerBSDArchive(module_sp, data_sp, data_offset, file, file_offset, length)); if (container_up) { // We already have this archive in our cache, use it container_up->SetArchive(archive_sp); return container_up.release(); } } } return nullptr; } bool ObjectContainerBSDArchive::MagicBytesMatch(const DataExtractor &data) { uint32_t offset = 0; const char *armag = (const char *)data.PeekData(offset, sizeof(ar_hdr)); if (armag && ::strncmp(armag, ARMAG, SARMAG) == 0) { armag += offsetof(struct ar_hdr, ar_fmag) + SARMAG; if (strncmp(armag, ARFMAG, 2) == 0) return true; } return false; } ObjectContainerBSDArchive::ObjectContainerBSDArchive( const lldb::ModuleSP &module_sp, DataBufferSP &data_sp, lldb::offset_t data_offset, const lldb_private::FileSpec *file, lldb::offset_t file_offset, lldb::offset_t size) : ObjectContainer(module_sp, file, file_offset, size, data_sp, data_offset), m_archive_sp() {} void ObjectContainerBSDArchive::SetArchive(Archive::shared_ptr &archive_sp) { m_archive_sp = archive_sp; } ObjectContainerBSDArchive::~ObjectContainerBSDArchive() {} bool ObjectContainerBSDArchive::ParseHeader() { if (m_archive_sp.get() == nullptr) { if (m_data.GetByteSize() > 0) { ModuleSP module_sp(GetModule()); if (module_sp) { m_archive_sp = Archive::ParseAndCacheArchiveForFile( m_file, module_sp->GetArchitecture(), module_sp->GetModificationTime(), m_offset, m_data); } // Clear the m_data that contains the entire archive data and let our // m_archive_sp hold onto the data. m_data.Clear(); } } return m_archive_sp.get() != nullptr; } void ObjectContainerBSDArchive::Dump(Stream *s) const { s->Printf("%p: ", static_cast(this)); s->Indent(); const size_t num_archs = GetNumArchitectures(); const size_t num_objects = GetNumObjects(); s->Printf("ObjectContainerBSDArchive, num_archs = %" PRIu64 ", num_objects = %" PRIu64 "", (uint64_t)num_archs, (uint64_t)num_objects); uint32_t i; ArchSpec arch; s->IndentMore(); for (i = 0; i < num_archs; i++) { s->Indent(); GetArchitectureAtIndex(i, arch); s->Printf("arch[%u] = %s\n", i, arch.GetArchitectureName()); } for (i = 0; i < num_objects; i++) { s->Indent(); s->Printf("object[%u] = %s\n", i, GetObjectNameAtIndex(i)); } s->IndentLess(); s->EOL(); } ObjectFileSP ObjectContainerBSDArchive::GetObjectFile(const FileSpec *file) { ModuleSP module_sp(GetModule()); if (module_sp) { if (module_sp->GetObjectName() && m_archive_sp) { Object *object = m_archive_sp->FindObject( module_sp->GetObjectName(), module_sp->GetObjectModificationTime()); if (object) { lldb::offset_t data_offset = object->file_offset; return ObjectFile::FindPlugin( module_sp, file, m_offset + object->file_offset, object->file_size, m_archive_sp->GetData().GetSharedDataBuffer(), data_offset); } } } return ObjectFileSP(); } // PluginInterface protocol lldb_private::ConstString ObjectContainerBSDArchive::GetPluginName() { return GetPluginNameStatic(); } uint32_t ObjectContainerBSDArchive::GetPluginVersion() { return 1; } size_t ObjectContainerBSDArchive::GetModuleSpecifications( const lldb_private::FileSpec &file, lldb::DataBufferSP &data_sp, lldb::offset_t data_offset, lldb::offset_t file_offset, lldb::offset_t file_size, lldb_private::ModuleSpecList &specs) { // We have data, which means this is the first 512 bytes of the file Check to // see if the magic bytes match and if they do, read the entire table of // contents for the archive and cache it DataExtractor data; data.SetData(data_sp, data_offset, data_sp->GetByteSize()); if (!file || !data_sp || !ObjectContainerBSDArchive::MagicBytesMatch(data)) return 0; const size_t initial_count = specs.GetSize(); llvm::sys::TimePoint<> file_mod_time = FileSystem::Instance().GetModificationTime(file); Archive::shared_ptr archive_sp( Archive::FindCachedArchive(file, ArchSpec(), file_mod_time, file_offset)); bool set_archive_arch = false; if (!archive_sp) { set_archive_arch = true; data_sp = FileSystem::Instance().CreateDataBuffer(file, file_size, file_offset); if (data_sp) { data.SetData(data_sp, 0, data_sp->GetByteSize()); archive_sp = Archive::ParseAndCacheArchiveForFile( file, ArchSpec(), file_mod_time, file_offset, data); } } if (archive_sp) { const size_t num_objects = archive_sp->GetNumObjects(); for (size_t idx = 0; idx < num_objects; ++idx) { const Object *object = archive_sp->GetObjectAtIndex(idx); if (object) { const lldb::offset_t object_file_offset = file_offset + object->file_offset; if (object->file_offset < file_size && file_size > object_file_offset) { if (ObjectFile::GetModuleSpecifications( file, object_file_offset, file_size - object_file_offset, specs)) { ModuleSpec &spec = specs.GetModuleSpecRefAtIndex(specs.GetSize() - 1); llvm::sys::TimePoint<> object_mod_time( std::chrono::seconds(object->modification_time)); spec.GetObjectName() = object->ar_name; spec.SetObjectOffset(object_file_offset); spec.SetObjectSize(file_size - object_file_offset); spec.GetObjectModificationTime() = object_mod_time; } } } } } const size_t end_count = specs.GetSize(); size_t num_specs_added = end_count - initial_count; if (set_archive_arch && num_specs_added > 0) { // The archive was created but we didn't have an architecture so we need to // set it for (size_t i = initial_count; i < end_count; ++i) { ModuleSpec module_spec; if (specs.GetModuleSpecAtIndex(i, module_spec)) { if (module_spec.GetArchitecture().IsValid()) { archive_sp->SetArchitecture(module_spec.GetArchitecture()); break; } } } } return num_specs_added; }