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