1 //===--------------------- ModuleCache.cpp ----------------------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #include "lldb/Target/ModuleCache.h" 11 12 #include "lldb/Core/Module.h" 13 #include "lldb/Core/ModuleList.h" 14 #include "lldb/Core/ModuleSpec.h" 15 #include "lldb/Host/File.h" 16 #include "lldb/Host/LockFile.h" 17 #include "lldb/Utility/Log.h" 18 #include "llvm/Support/FileSystem.h" 19 #include "llvm/Support/FileUtilities.h" 20 21 #include <assert.h> 22 23 #include <cstdio> 24 25 using namespace lldb; 26 using namespace lldb_private; 27 28 namespace { 29 30 const char *kModulesSubdir = ".cache"; 31 const char *kLockDirName = ".lock"; 32 const char *kTempFileName = ".temp"; 33 const char *kTempSymFileName = ".symtemp"; 34 const char *kSymFileExtension = ".sym"; 35 const char *kFSIllegalChars = "\\/:*?\"<>|"; 36 37 std::string GetEscapedHostname(const char *hostname) { 38 if (hostname == nullptr) 39 hostname = "unknown"; 40 std::string result(hostname); 41 size_t size = result.size(); 42 for (size_t i = 0; i < size; ++i) { 43 if ((result[i] >= 1 && result[i] <= 31) || 44 strchr(kFSIllegalChars, result[i]) != nullptr) 45 result[i] = '_'; 46 } 47 return result; 48 } 49 50 class ModuleLock { 51 private: 52 File m_file; 53 std::unique_ptr<lldb_private::LockFile> m_lock; 54 FileSpec m_file_spec; 55 56 public: 57 ModuleLock(const FileSpec &root_dir_spec, const UUID &uuid, Status &error); 58 void Delete(); 59 }; 60 61 static FileSpec JoinPath(const FileSpec &path1, const char *path2) { 62 FileSpec result_spec(path1); 63 result_spec.AppendPathComponent(path2); 64 return result_spec; 65 } 66 67 static Status MakeDirectory(const FileSpec &dir_path) { 68 namespace fs = llvm::sys::fs; 69 70 return fs::create_directories(dir_path.GetPath(), true, fs::perms::owner_all); 71 } 72 73 FileSpec GetModuleDirectory(const FileSpec &root_dir_spec, const UUID &uuid) { 74 const auto modules_dir_spec = JoinPath(root_dir_spec, kModulesSubdir); 75 return JoinPath(modules_dir_spec, uuid.GetAsString().c_str()); 76 } 77 78 FileSpec GetSymbolFileSpec(const FileSpec &module_file_spec) { 79 return FileSpec(module_file_spec.GetPath() + kSymFileExtension, false); 80 } 81 82 void DeleteExistingModule(const FileSpec &root_dir_spec, 83 const FileSpec &sysroot_module_path_spec) { 84 Log *log(GetLogIfAllCategoriesSet(LIBLLDB_LOG_MODULES)); 85 UUID module_uuid; 86 { 87 auto module_sp = 88 std::make_shared<Module>(ModuleSpec(sysroot_module_path_spec)); 89 module_uuid = module_sp->GetUUID(); 90 } 91 92 if (!module_uuid.IsValid()) 93 return; 94 95 Status error; 96 ModuleLock lock(root_dir_spec, module_uuid, error); 97 if (error.Fail()) { 98 if (log) 99 log->Printf("Failed to lock module %s: %s", 100 module_uuid.GetAsString().c_str(), error.AsCString()); 101 } 102 103 namespace fs = llvm::sys::fs; 104 fs::file_status st; 105 if (status(sysroot_module_path_spec.GetPath(), st)) 106 return; 107 108 if (st.getLinkCount() > 2) // module is referred by other hosts. 109 return; 110 111 const auto module_spec_dir = GetModuleDirectory(root_dir_spec, module_uuid); 112 llvm::sys::fs::remove_directories(module_spec_dir.GetPath()); 113 lock.Delete(); 114 } 115 116 void DecrementRefExistingModule(const FileSpec &root_dir_spec, 117 const FileSpec &sysroot_module_path_spec) { 118 // Remove $platform/.cache/$uuid folder if nobody else references it. 119 DeleteExistingModule(root_dir_spec, sysroot_module_path_spec); 120 121 // Remove sysroot link. 122 llvm::sys::fs::remove(sysroot_module_path_spec.GetPath()); 123 124 FileSpec symfile_spec = GetSymbolFileSpec(sysroot_module_path_spec); 125 llvm::sys::fs::remove(symfile_spec.GetPath()); 126 } 127 128 Status CreateHostSysRootModuleLink(const FileSpec &root_dir_spec, 129 const char *hostname, 130 const FileSpec &platform_module_spec, 131 const FileSpec &local_module_spec, 132 bool delete_existing) { 133 const auto sysroot_module_path_spec = 134 JoinPath(JoinPath(root_dir_spec, hostname), 135 platform_module_spec.GetPath().c_str()); 136 if (sysroot_module_path_spec.Exists()) { 137 if (!delete_existing) 138 return Status(); 139 140 DecrementRefExistingModule(root_dir_spec, sysroot_module_path_spec); 141 } 142 143 const auto error = MakeDirectory( 144 FileSpec(sysroot_module_path_spec.GetDirectory().AsCString(), false)); 145 if (error.Fail()) 146 return error; 147 148 return llvm::sys::fs::create_hard_link(local_module_spec.GetPath(), 149 sysroot_module_path_spec.GetPath()); 150 } 151 152 } // namespace 153 154 ModuleLock::ModuleLock(const FileSpec &root_dir_spec, const UUID &uuid, 155 Status &error) { 156 const auto lock_dir_spec = JoinPath(root_dir_spec, kLockDirName); 157 error = MakeDirectory(lock_dir_spec); 158 if (error.Fail()) 159 return; 160 161 m_file_spec = JoinPath(lock_dir_spec, uuid.GetAsString().c_str()); 162 m_file.Open(m_file_spec.GetCString(), File::eOpenOptionWrite | 163 File::eOpenOptionCanCreate | 164 File::eOpenOptionCloseOnExec); 165 if (!m_file) { 166 error.SetErrorToErrno(); 167 return; 168 } 169 170 m_lock.reset(new lldb_private::LockFile(m_file.GetDescriptor())); 171 error = m_lock->WriteLock(0, 1); 172 if (error.Fail()) 173 error.SetErrorStringWithFormat("Failed to lock file: %s", 174 error.AsCString()); 175 } 176 177 void ModuleLock::Delete() { 178 if (!m_file) 179 return; 180 181 m_file.Close(); 182 llvm::sys::fs::remove(m_file_spec.GetPath()); 183 } 184 185 ///////////////////////////////////////////////////////////////////////// 186 187 Status ModuleCache::Put(const FileSpec &root_dir_spec, const char *hostname, 188 const ModuleSpec &module_spec, const FileSpec &tmp_file, 189 const FileSpec &target_file) { 190 const auto module_spec_dir = 191 GetModuleDirectory(root_dir_spec, module_spec.GetUUID()); 192 const auto module_file_path = 193 JoinPath(module_spec_dir, target_file.GetFilename().AsCString()); 194 195 const auto tmp_file_path = tmp_file.GetPath(); 196 const auto err_code = 197 llvm::sys::fs::rename(tmp_file_path, module_file_path.GetPath()); 198 if (err_code) 199 return Status("Failed to rename file %s to %s: %s", tmp_file_path.c_str(), 200 module_file_path.GetPath().c_str(), 201 err_code.message().c_str()); 202 203 const auto error = CreateHostSysRootModuleLink( 204 root_dir_spec, hostname, target_file, module_file_path, true); 205 if (error.Fail()) 206 return Status("Failed to create link to %s: %s", 207 module_file_path.GetPath().c_str(), error.AsCString()); 208 return Status(); 209 } 210 211 Status ModuleCache::Get(const FileSpec &root_dir_spec, const char *hostname, 212 const ModuleSpec &module_spec, 213 ModuleSP &cached_module_sp, bool *did_create_ptr) { 214 const auto find_it = 215 m_loaded_modules.find(module_spec.GetUUID().GetAsString()); 216 if (find_it != m_loaded_modules.end()) { 217 cached_module_sp = (*find_it).second.lock(); 218 if (cached_module_sp) 219 return Status(); 220 m_loaded_modules.erase(find_it); 221 } 222 223 const auto module_spec_dir = 224 GetModuleDirectory(root_dir_spec, module_spec.GetUUID()); 225 const auto module_file_path = JoinPath( 226 module_spec_dir, module_spec.GetFileSpec().GetFilename().AsCString()); 227 228 if (!module_file_path.Exists()) 229 return Status("Module %s not found", module_file_path.GetPath().c_str()); 230 if (FileSystem::Instance().GetByteSize(module_file_path) != 231 module_spec.GetObjectSize()) 232 return Status("Module %s has invalid file size", 233 module_file_path.GetPath().c_str()); 234 235 // We may have already cached module but downloaded from an another host - in 236 // this case let's create a link to it. 237 auto error = CreateHostSysRootModuleLink(root_dir_spec, hostname, 238 module_spec.GetFileSpec(), 239 module_file_path, false); 240 if (error.Fail()) 241 return Status("Failed to create link to %s: %s", 242 module_file_path.GetPath().c_str(), error.AsCString()); 243 244 auto cached_module_spec(module_spec); 245 cached_module_spec.GetUUID().Clear(); // Clear UUID since it may contain md5 246 // content hash instead of real UUID. 247 cached_module_spec.GetFileSpec() = module_file_path; 248 cached_module_spec.GetPlatformFileSpec() = module_spec.GetFileSpec(); 249 250 error = ModuleList::GetSharedModule(cached_module_spec, cached_module_sp, 251 nullptr, nullptr, did_create_ptr, false); 252 if (error.Fail()) 253 return error; 254 255 FileSpec symfile_spec = GetSymbolFileSpec(cached_module_sp->GetFileSpec()); 256 if (symfile_spec.Exists()) 257 cached_module_sp->SetSymbolFileFileSpec(symfile_spec); 258 259 m_loaded_modules.insert( 260 std::make_pair(module_spec.GetUUID().GetAsString(), cached_module_sp)); 261 262 return Status(); 263 } 264 265 Status ModuleCache::GetAndPut(const FileSpec &root_dir_spec, 266 const char *hostname, 267 const ModuleSpec &module_spec, 268 const ModuleDownloader &module_downloader, 269 const SymfileDownloader &symfile_downloader, 270 lldb::ModuleSP &cached_module_sp, 271 bool *did_create_ptr) { 272 const auto module_spec_dir = 273 GetModuleDirectory(root_dir_spec, module_spec.GetUUID()); 274 auto error = MakeDirectory(module_spec_dir); 275 if (error.Fail()) 276 return error; 277 278 ModuleLock lock(root_dir_spec, module_spec.GetUUID(), error); 279 if (error.Fail()) 280 return Status("Failed to lock module %s: %s", 281 module_spec.GetUUID().GetAsString().c_str(), 282 error.AsCString()); 283 284 const auto escaped_hostname(GetEscapedHostname(hostname)); 285 // Check local cache for a module. 286 error = Get(root_dir_spec, escaped_hostname.c_str(), module_spec, 287 cached_module_sp, did_create_ptr); 288 if (error.Success()) 289 return error; 290 291 const auto tmp_download_file_spec = JoinPath(module_spec_dir, kTempFileName); 292 error = module_downloader(module_spec, tmp_download_file_spec); 293 llvm::FileRemover tmp_file_remover(tmp_download_file_spec.GetPath()); 294 if (error.Fail()) 295 return Status("Failed to download module: %s", error.AsCString()); 296 297 // Put downloaded file into local module cache. 298 error = Put(root_dir_spec, escaped_hostname.c_str(), module_spec, 299 tmp_download_file_spec, module_spec.GetFileSpec()); 300 if (error.Fail()) 301 return Status("Failed to put module into cache: %s", error.AsCString()); 302 303 tmp_file_remover.releaseFile(); 304 error = Get(root_dir_spec, escaped_hostname.c_str(), module_spec, 305 cached_module_sp, did_create_ptr); 306 if (error.Fail()) 307 return error; 308 309 // Fetching a symbol file for the module 310 const auto tmp_download_sym_file_spec = 311 JoinPath(module_spec_dir, kTempSymFileName); 312 error = symfile_downloader(cached_module_sp, tmp_download_sym_file_spec); 313 llvm::FileRemover tmp_symfile_remover(tmp_download_sym_file_spec.GetPath()); 314 if (error.Fail()) 315 // Failed to download a symfile but fetching the module was successful. The 316 // module might contain the necessary symbols and the debugging is also 317 // possible without a symfile. 318 return Status(); 319 320 error = Put(root_dir_spec, escaped_hostname.c_str(), module_spec, 321 tmp_download_sym_file_spec, 322 GetSymbolFileSpec(module_spec.GetFileSpec())); 323 if (error.Fail()) 324 return Status("Failed to put symbol file into cache: %s", 325 error.AsCString()); 326 327 tmp_symfile_remover.releaseFile(); 328 329 FileSpec symfile_spec = GetSymbolFileSpec(cached_module_sp->GetFileSpec()); 330 cached_module_sp->SetSymbolFileFileSpec(symfile_spec); 331 return Status(); 332 } 333