1 //===-- llvm-lto2: test harness for the resolution-based LTO interface ----===// 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 // This program takes in a list of bitcode files, links them and performs 10 // link-time optimization according to the provided symbol resolutions using the 11 // resolution-based LTO interface, and outputs one or more object files. 12 // 13 // This program is intended to eventually replace llvm-lto which uses the legacy 14 // LTO interface. 15 // 16 //===----------------------------------------------------------------------===// 17 18 #include "llvm/Bitcode/BitcodeReader.h" 19 #include "llvm/CodeGen/CommandFlags.h" 20 #include "llvm/IR/DiagnosticPrinter.h" 21 #include "llvm/LTO/Caching.h" 22 #include "llvm/LTO/LTO.h" 23 #include "llvm/Passes/PassPlugin.h" 24 #include "llvm/Support/CommandLine.h" 25 #include "llvm/Support/FileSystem.h" 26 #include "llvm/Support/InitLLVM.h" 27 #include "llvm/Support/PluginLoader.h" 28 #include "llvm/Support/TargetSelect.h" 29 #include "llvm/Support/Threading.h" 30 31 using namespace llvm; 32 using namespace lto; 33 34 static codegen::RegisterCodeGenFlags CGF; 35 36 static cl::opt<char> 37 OptLevel("O", cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] " 38 "(default = '-O2')"), 39 cl::Prefix, cl::ZeroOrMore, cl::init('2')); 40 41 static cl::opt<char> CGOptLevel( 42 "cg-opt-level", 43 cl::desc("Codegen optimization level (0, 1, 2 or 3, default = '2')"), 44 cl::init('2')); 45 46 static cl::list<std::string> InputFilenames(cl::Positional, cl::OneOrMore, 47 cl::desc("<input bitcode files>")); 48 49 static cl::opt<std::string> OutputFilename("o", cl::Required, 50 cl::desc("Output filename"), 51 cl::value_desc("filename")); 52 53 static cl::opt<std::string> CacheDir("cache-dir", cl::desc("Cache Directory"), 54 cl::value_desc("directory")); 55 56 static cl::opt<std::string> OptPipeline("opt-pipeline", 57 cl::desc("Optimizer Pipeline"), 58 cl::value_desc("pipeline")); 59 60 static cl::opt<std::string> AAPipeline("aa-pipeline", 61 cl::desc("Alias Analysis Pipeline"), 62 cl::value_desc("aapipeline")); 63 64 static cl::opt<bool> SaveTemps("save-temps", cl::desc("Save temporary files")); 65 66 static cl::opt<bool> 67 ThinLTODistributedIndexes("thinlto-distributed-indexes", cl::init(false), 68 cl::desc("Write out individual index and " 69 "import files for the " 70 "distributed backend case")); 71 72 // Default to using all available threads in the system, but using only one 73 // thread per core (no SMT). 74 // Use -thinlto-threads=all to use hardware_concurrency() instead, which means 75 // to use all hardware threads or cores in the system. 76 static cl::opt<std::string> Threads("thinlto-threads"); 77 78 static cl::list<std::string> SymbolResolutions( 79 "r", 80 cl::desc("Specify a symbol resolution: filename,symbolname,resolution\n" 81 "where \"resolution\" is a sequence (which may be empty) of the\n" 82 "following characters:\n" 83 " p - prevailing: the linker has chosen this definition of the\n" 84 " symbol\n" 85 " l - local: the definition of this symbol is unpreemptable at\n" 86 " runtime and is known to be in this linkage unit\n" 87 " x - externally visible: the definition of this symbol is\n" 88 " visible outside of the LTO unit\n" 89 "A resolution for each symbol must be specified."), 90 cl::ZeroOrMore); 91 92 static cl::opt<std::string> OverrideTriple( 93 "override-triple", 94 cl::desc("Replace target triples in input files with this triple")); 95 96 static cl::opt<std::string> DefaultTriple( 97 "default-triple", 98 cl::desc( 99 "Replace unspecified target triples in input files with this triple")); 100 101 static cl::opt<bool> RemarksWithHotness( 102 "pass-remarks-with-hotness", 103 cl::desc("With PGO, include profile count in optimization remarks"), 104 cl::Hidden); 105 106 static cl::opt<std::string> 107 RemarksFilename("pass-remarks-output", 108 cl::desc("Output filename for pass remarks"), 109 cl::value_desc("filename")); 110 111 static cl::opt<std::string> 112 RemarksPasses("pass-remarks-filter", 113 cl::desc("Only record optimization remarks from passes whose " 114 "names match the given regular expression"), 115 cl::value_desc("regex")); 116 117 static cl::opt<std::string> RemarksFormat( 118 "pass-remarks-format", 119 cl::desc("The format used for serializing remarks (default: YAML)"), 120 cl::value_desc("format"), cl::init("yaml")); 121 122 static cl::opt<std::string> 123 SamplePGOFile("lto-sample-profile-file", 124 cl::desc("Specify a SamplePGO profile file")); 125 126 static cl::opt<std::string> 127 CSPGOFile("lto-cspgo-profile-file", 128 cl::desc("Specify a context sensitive PGO profile file")); 129 130 static cl::opt<bool> 131 RunCSIRInstr("lto-cspgo-gen", 132 cl::desc("Run PGO context sensitive IR instrumentation"), 133 cl::init(false), cl::Hidden); 134 135 static cl::opt<bool> 136 UseNewPM("use-new-pm", 137 cl::desc("Run LTO passes using the new pass manager"), 138 cl::init(false), cl::Hidden); 139 140 static cl::opt<bool> 141 DebugPassManager("debug-pass-manager", cl::init(false), cl::Hidden, 142 cl::desc("Print pass management debugging information")); 143 144 static cl::opt<std::string> 145 StatsFile("stats-file", cl::desc("Filename to write statistics to")); 146 147 static cl::list<std::string> 148 PassPlugins("load-pass-plugin", 149 cl::desc("Load passes from plugin library")); 150 151 static void check(Error E, std::string Msg) { 152 if (!E) 153 return; 154 handleAllErrors(std::move(E), [&](ErrorInfoBase &EIB) { 155 errs() << "llvm-lto2: " << Msg << ": " << EIB.message().c_str() << '\n'; 156 }); 157 exit(1); 158 } 159 160 template <typename T> static T check(Expected<T> E, std::string Msg) { 161 if (E) 162 return std::move(*E); 163 check(E.takeError(), Msg); 164 return T(); 165 } 166 167 static void check(std::error_code EC, std::string Msg) { 168 check(errorCodeToError(EC), Msg); 169 } 170 171 template <typename T> static T check(ErrorOr<T> E, std::string Msg) { 172 if (E) 173 return std::move(*E); 174 check(E.getError(), Msg); 175 return T(); 176 } 177 178 static int usage() { 179 errs() << "Available subcommands: dump-symtab run\n"; 180 return 1; 181 } 182 183 static int run(int argc, char **argv) { 184 cl::ParseCommandLineOptions(argc, argv, "Resolution-based LTO test harness"); 185 186 // FIXME: Workaround PR30396 which means that a symbol can appear 187 // more than once if it is defined in module-level assembly and 188 // has a GV declaration. We allow (file, symbol) pairs to have multiple 189 // resolutions and apply them in the order observed. 190 std::map<std::pair<std::string, std::string>, std::list<SymbolResolution>> 191 CommandLineResolutions; 192 for (std::string R : SymbolResolutions) { 193 StringRef Rest = R; 194 StringRef FileName, SymbolName; 195 std::tie(FileName, Rest) = Rest.split(','); 196 if (Rest.empty()) { 197 llvm::errs() << "invalid resolution: " << R << '\n'; 198 return 1; 199 } 200 std::tie(SymbolName, Rest) = Rest.split(','); 201 SymbolResolution Res; 202 for (char C : Rest) { 203 if (C == 'p') 204 Res.Prevailing = true; 205 else if (C == 'l') 206 Res.FinalDefinitionInLinkageUnit = true; 207 else if (C == 'x') 208 Res.VisibleToRegularObj = true; 209 else if (C == 'r') 210 Res.LinkerRedefined = true; 211 else { 212 llvm::errs() << "invalid character " << C << " in resolution: " << R 213 << '\n'; 214 return 1; 215 } 216 } 217 CommandLineResolutions[{std::string(FileName), std::string(SymbolName)}] 218 .push_back(Res); 219 } 220 221 std::vector<std::unique_ptr<MemoryBuffer>> MBs; 222 223 Config Conf; 224 Conf.DiagHandler = [](const DiagnosticInfo &DI) { 225 DiagnosticPrinterRawOStream DP(errs()); 226 DI.print(DP); 227 errs() << '\n'; 228 if (DI.getSeverity() == DS_Error) 229 exit(1); 230 }; 231 232 Conf.CPU = codegen::getMCPU(); 233 Conf.Options = codegen::InitTargetOptionsFromCodeGenFlags(); 234 Conf.MAttrs = codegen::getMAttrs(); 235 if (auto RM = codegen::getExplicitRelocModel()) 236 Conf.RelocModel = RM.getValue(); 237 Conf.CodeModel = codegen::getExplicitCodeModel(); 238 239 Conf.DebugPassManager = DebugPassManager; 240 241 if (SaveTemps) 242 check(Conf.addSaveTemps(OutputFilename + "."), 243 "Config::addSaveTemps failed"); 244 245 // Optimization remarks. 246 Conf.RemarksFilename = RemarksFilename; 247 Conf.RemarksPasses = RemarksPasses; 248 Conf.RemarksWithHotness = RemarksWithHotness; 249 Conf.RemarksFormat = RemarksFormat; 250 251 Conf.SampleProfile = SamplePGOFile; 252 Conf.CSIRProfile = CSPGOFile; 253 Conf.RunCSIRInstr = RunCSIRInstr; 254 255 // Run a custom pipeline, if asked for. 256 Conf.OptPipeline = OptPipeline; 257 Conf.AAPipeline = AAPipeline; 258 259 Conf.OptLevel = OptLevel - '0'; 260 Conf.UseNewPM = UseNewPM; 261 for (auto &PluginFN : PassPlugins) 262 Conf.PassPlugins.push_back(PluginFN); 263 switch (CGOptLevel) { 264 case '0': 265 Conf.CGOptLevel = CodeGenOpt::None; 266 break; 267 case '1': 268 Conf.CGOptLevel = CodeGenOpt::Less; 269 break; 270 case '2': 271 Conf.CGOptLevel = CodeGenOpt::Default; 272 break; 273 case '3': 274 Conf.CGOptLevel = CodeGenOpt::Aggressive; 275 break; 276 default: 277 llvm::errs() << "invalid cg optimization level: " << CGOptLevel << '\n'; 278 return 1; 279 } 280 281 if (auto FT = codegen::getExplicitFileType()) 282 Conf.CGFileType = FT.getValue(); 283 284 Conf.OverrideTriple = OverrideTriple; 285 Conf.DefaultTriple = DefaultTriple; 286 Conf.StatsFile = StatsFile; 287 Conf.PTO.LoopVectorization = Conf.OptLevel > 1; 288 Conf.PTO.SLPVectorization = Conf.OptLevel > 1; 289 290 ThinBackend Backend; 291 if (ThinLTODistributedIndexes) 292 Backend = createWriteIndexesThinBackend(/* OldPrefix */ "", 293 /* NewPrefix */ "", 294 /* ShouldEmitImportsFiles */ true, 295 /* LinkedObjectsFile */ nullptr, 296 /* OnWrite */ {}); 297 else 298 Backend = createInProcessThinBackend( 299 llvm::heavyweight_hardware_concurrency(Threads)); 300 LTO Lto(std::move(Conf), std::move(Backend)); 301 302 bool HasErrors = false; 303 for (std::string F : InputFilenames) { 304 std::unique_ptr<MemoryBuffer> MB = check(MemoryBuffer::getFile(F), F); 305 std::unique_ptr<InputFile> Input = 306 check(InputFile::create(MB->getMemBufferRef()), F); 307 308 std::vector<SymbolResolution> Res; 309 for (const InputFile::Symbol &Sym : Input->symbols()) { 310 auto I = CommandLineResolutions.find({F, std::string(Sym.getName())}); 311 // If it isn't found, look for "$", which would have been added 312 // (followed by a hash) when the symbol was promoted during module 313 // splitting if it was defined in one part and used in the other. 314 // Try looking up the symbol name before the "$". 315 if (I == CommandLineResolutions.end()) { 316 auto SplitName = Sym.getName().rsplit("$"); 317 I = CommandLineResolutions.find({F, std::string(SplitName.first)}); 318 } 319 if (I == CommandLineResolutions.end()) { 320 llvm::errs() << argv[0] << ": missing symbol resolution for " << F 321 << ',' << Sym.getName() << '\n'; 322 HasErrors = true; 323 } else { 324 Res.push_back(I->second.front()); 325 I->second.pop_front(); 326 if (I->second.empty()) 327 CommandLineResolutions.erase(I); 328 } 329 } 330 331 if (HasErrors) 332 continue; 333 334 MBs.push_back(std::move(MB)); 335 check(Lto.add(std::move(Input), Res), F); 336 } 337 338 if (!CommandLineResolutions.empty()) { 339 HasErrors = true; 340 for (auto UnusedRes : CommandLineResolutions) 341 llvm::errs() << argv[0] << ": unused symbol resolution for " 342 << UnusedRes.first.first << ',' << UnusedRes.first.second 343 << '\n'; 344 } 345 if (HasErrors) 346 return 1; 347 348 auto AddStream = 349 [&](size_t Task) -> std::unique_ptr<lto::NativeObjectStream> { 350 std::string Path = OutputFilename + "." + utostr(Task); 351 352 std::error_code EC; 353 auto S = std::make_unique<raw_fd_ostream>(Path, EC, sys::fs::OF_None); 354 check(EC, Path); 355 return std::make_unique<lto::NativeObjectStream>(std::move(S)); 356 }; 357 358 auto AddBuffer = [&](size_t Task, std::unique_ptr<MemoryBuffer> MB) { 359 *AddStream(Task)->OS << MB->getBuffer(); 360 }; 361 362 NativeObjectCache Cache; 363 if (!CacheDir.empty()) 364 Cache = check(localCache(CacheDir, AddBuffer), "failed to create cache"); 365 366 check(Lto.run(AddStream, Cache), "LTO::run failed"); 367 return 0; 368 } 369 370 static int dumpSymtab(int argc, char **argv) { 371 for (StringRef F : make_range(argv + 1, argv + argc)) { 372 std::unique_ptr<MemoryBuffer> MB = 373 check(MemoryBuffer::getFile(F), std::string(F)); 374 BitcodeFileContents BFC = 375 check(getBitcodeFileContents(*MB), std::string(F)); 376 377 if (BFC.Symtab.size() >= sizeof(irsymtab::storage::Header)) { 378 auto *Hdr = reinterpret_cast<const irsymtab::storage::Header *>( 379 BFC.Symtab.data()); 380 outs() << "version: " << Hdr->Version << '\n'; 381 if (Hdr->Version == irsymtab::storage::Header::kCurrentVersion) 382 outs() << "producer: " << Hdr->Producer.get(BFC.StrtabForSymtab) 383 << '\n'; 384 } 385 386 std::unique_ptr<InputFile> Input = 387 check(InputFile::create(MB->getMemBufferRef()), std::string(F)); 388 389 outs() << "target triple: " << Input->getTargetTriple() << '\n'; 390 Triple TT(Input->getTargetTriple()); 391 392 outs() << "source filename: " << Input->getSourceFileName() << '\n'; 393 394 if (TT.isOSBinFormatCOFF()) 395 outs() << "linker opts: " << Input->getCOFFLinkerOpts() << '\n'; 396 397 if (TT.isOSBinFormatELF()) { 398 outs() << "dependent libraries:"; 399 for (auto L : Input->getDependentLibraries()) 400 outs() << " \"" << L << "\""; 401 outs() << '\n'; 402 } 403 404 std::vector<StringRef> ComdatTable = Input->getComdatTable(); 405 for (const InputFile::Symbol &Sym : Input->symbols()) { 406 switch (Sym.getVisibility()) { 407 case GlobalValue::HiddenVisibility: 408 outs() << 'H'; 409 break; 410 case GlobalValue::ProtectedVisibility: 411 outs() << 'P'; 412 break; 413 case GlobalValue::DefaultVisibility: 414 outs() << 'D'; 415 break; 416 } 417 418 auto PrintBool = [&](char C, bool B) { outs() << (B ? C : '-'); }; 419 PrintBool('U', Sym.isUndefined()); 420 PrintBool('C', Sym.isCommon()); 421 PrintBool('W', Sym.isWeak()); 422 PrintBool('I', Sym.isIndirect()); 423 PrintBool('O', Sym.canBeOmittedFromSymbolTable()); 424 PrintBool('T', Sym.isTLS()); 425 PrintBool('X', Sym.isExecutable()); 426 outs() << ' ' << Sym.getName() << '\n'; 427 428 if (Sym.isCommon()) 429 outs() << " size " << Sym.getCommonSize() << " align " 430 << Sym.getCommonAlignment() << '\n'; 431 432 int Comdat = Sym.getComdatIndex(); 433 if (Comdat != -1) 434 outs() << " comdat " << ComdatTable[Comdat] << '\n'; 435 436 if (TT.isOSBinFormatCOFF() && Sym.isWeak() && Sym.isIndirect()) 437 outs() << " fallback " << Sym.getCOFFWeakExternalFallback() << '\n'; 438 439 if (!Sym.getSectionName().empty()) 440 outs() << " section " << Sym.getSectionName() << "\n"; 441 } 442 443 outs() << '\n'; 444 } 445 446 return 0; 447 } 448 449 int main(int argc, char **argv) { 450 InitLLVM X(argc, argv); 451 InitializeAllTargets(); 452 InitializeAllTargetMCs(); 453 InitializeAllAsmPrinters(); 454 InitializeAllAsmParsers(); 455 456 // FIXME: This should use llvm::cl subcommands, but it isn't currently 457 // possible to pass an argument not associated with a subcommand to a 458 // subcommand (e.g. -use-new-pm). 459 if (argc < 2) 460 return usage(); 461 462 StringRef Subcommand = argv[1]; 463 // Ensure that argv[0] is correct after adjusting argv/argc. 464 argv[1] = argv[0]; 465 if (Subcommand == "dump-symtab") 466 return dumpSymtab(argc - 1, argv + 1); 467 if (Subcommand == "run") 468 return run(argc - 1, argv + 1); 469 return usage(); 470 } 471