| File: | llvm/lib/LTO/LTOBackend.cpp |
| Warning: | line 248, column 40 Called C++ object pointer is null |
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| 1 | //===-LTOBackend.cpp - LLVM Link Time Optimizer Backend -------------------===// | |||
| 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 file implements the "backend" phase of LTO, i.e. it performs | |||
| 10 | // optimization and code generation on a loaded module. It is generally used | |||
| 11 | // internally by the LTO class but can also be used independently, for example | |||
| 12 | // to implement a standalone ThinLTO backend. | |||
| 13 | // | |||
| 14 | //===----------------------------------------------------------------------===// | |||
| 15 | ||||
| 16 | #include "llvm/LTO/LTOBackend.h" | |||
| 17 | #include "llvm/Analysis/AliasAnalysis.h" | |||
| 18 | #include "llvm/Analysis/CGSCCPassManager.h" | |||
| 19 | #include "llvm/Analysis/ModuleSummaryAnalysis.h" | |||
| 20 | #include "llvm/Analysis/TargetLibraryInfo.h" | |||
| 21 | #include "llvm/Analysis/TargetTransformInfo.h" | |||
| 22 | #include "llvm/Bitcode/BitcodeReader.h" | |||
| 23 | #include "llvm/Bitcode/BitcodeWriter.h" | |||
| 24 | #include "llvm/IR/LLVMRemarkStreamer.h" | |||
| 25 | #include "llvm/IR/LegacyPassManager.h" | |||
| 26 | #include "llvm/IR/PassManager.h" | |||
| 27 | #include "llvm/IR/Verifier.h" | |||
| 28 | #include "llvm/LTO/LTO.h" | |||
| 29 | #include "llvm/MC/SubtargetFeature.h" | |||
| 30 | #include "llvm/MC/TargetRegistry.h" | |||
| 31 | #include "llvm/Object/ModuleSymbolTable.h" | |||
| 32 | #include "llvm/Passes/PassBuilder.h" | |||
| 33 | #include "llvm/Passes/PassPlugin.h" | |||
| 34 | #include "llvm/Passes/StandardInstrumentations.h" | |||
| 35 | #include "llvm/Support/Error.h" | |||
| 36 | #include "llvm/Support/FileSystem.h" | |||
| 37 | #include "llvm/Support/MemoryBuffer.h" | |||
| 38 | #include "llvm/Support/Path.h" | |||
| 39 | #include "llvm/Support/Program.h" | |||
| 40 | #include "llvm/Support/ThreadPool.h" | |||
| 41 | #include "llvm/Support/raw_ostream.h" | |||
| 42 | #include "llvm/Target/TargetMachine.h" | |||
| 43 | #include "llvm/Transforms/IPO.h" | |||
| 44 | #include "llvm/Transforms/IPO/PassManagerBuilder.h" | |||
| 45 | #include "llvm/Transforms/Scalar/LoopPassManager.h" | |||
| 46 | #include "llvm/Transforms/Utils/FunctionImportUtils.h" | |||
| 47 | #include "llvm/Transforms/Utils/SplitModule.h" | |||
| 48 | ||||
| 49 | using namespace llvm; | |||
| 50 | using namespace lto; | |||
| 51 | ||||
| 52 | #define DEBUG_TYPE"lto-backend" "lto-backend" | |||
| 53 | ||||
| 54 | enum class LTOBitcodeEmbedding { | |||
| 55 | DoNotEmbed = 0, | |||
| 56 | EmbedOptimized = 1, | |||
| 57 | EmbedPostMergePreOptimized = 2 | |||
| 58 | }; | |||
| 59 | ||||
| 60 | static cl::opt<LTOBitcodeEmbedding> EmbedBitcode( | |||
| 61 | "lto-embed-bitcode", cl::init(LTOBitcodeEmbedding::DoNotEmbed), | |||
| 62 | cl::values(clEnumValN(LTOBitcodeEmbedding::DoNotEmbed, "none",llvm::cl::OptionEnumValue { "none", int(LTOBitcodeEmbedding:: DoNotEmbed), "Do not embed" } | |||
| 63 | "Do not embed")llvm::cl::OptionEnumValue { "none", int(LTOBitcodeEmbedding:: DoNotEmbed), "Do not embed" }, | |||
| 64 | clEnumValN(LTOBitcodeEmbedding::EmbedOptimized, "optimized",llvm::cl::OptionEnumValue { "optimized", int(LTOBitcodeEmbedding ::EmbedOptimized), "Embed after all optimization passes" } | |||
| 65 | "Embed after all optimization passes")llvm::cl::OptionEnumValue { "optimized", int(LTOBitcodeEmbedding ::EmbedOptimized), "Embed after all optimization passes" }, | |||
| 66 | clEnumValN(LTOBitcodeEmbedding::EmbedPostMergePreOptimized,llvm::cl::OptionEnumValue { "post-merge-pre-opt", int(LTOBitcodeEmbedding ::EmbedPostMergePreOptimized), "Embed post merge, but before optimizations" } | |||
| 67 | "post-merge-pre-opt",llvm::cl::OptionEnumValue { "post-merge-pre-opt", int(LTOBitcodeEmbedding ::EmbedPostMergePreOptimized), "Embed post merge, but before optimizations" } | |||
| 68 | "Embed post merge, but before optimizations")llvm::cl::OptionEnumValue { "post-merge-pre-opt", int(LTOBitcodeEmbedding ::EmbedPostMergePreOptimized), "Embed post merge, but before optimizations" }), | |||
| 69 | cl::desc("Embed LLVM bitcode in object files produced by LTO")); | |||
| 70 | ||||
| 71 | static cl::opt<bool> ThinLTOAssumeMerged( | |||
| 72 | "thinlto-assume-merged", cl::init(false), | |||
| 73 | cl::desc("Assume the input has already undergone ThinLTO function " | |||
| 74 | "importing and the other pre-optimization pipeline changes.")); | |||
| 75 | ||||
| 76 | namespace llvm { | |||
| 77 | extern cl::opt<bool> NoPGOWarnMismatch; | |||
| 78 | } | |||
| 79 | ||||
| 80 | [[noreturn]] static void reportOpenError(StringRef Path, Twine Msg) { | |||
| 81 | errs() << "failed to open " << Path << ": " << Msg << '\n'; | |||
| 82 | errs().flush(); | |||
| 83 | exit(1); | |||
| 84 | } | |||
| 85 | ||||
| 86 | Error Config::addSaveTemps(std::string OutputFileName, | |||
| 87 | bool UseInputModulePath) { | |||
| 88 | ShouldDiscardValueNames = false; | |||
| 89 | ||||
| 90 | std::error_code EC; | |||
| 91 | ResolutionFile = | |||
| 92 | std::make_unique<raw_fd_ostream>(OutputFileName + "resolution.txt", EC, | |||
| 93 | sys::fs::OpenFlags::OF_TextWithCRLF); | |||
| 94 | if (EC) { | |||
| 95 | ResolutionFile.reset(); | |||
| 96 | return errorCodeToError(EC); | |||
| 97 | } | |||
| 98 | ||||
| 99 | auto setHook = [&](std::string PathSuffix, ModuleHookFn &Hook) { | |||
| 100 | // Keep track of the hook provided by the linker, which also needs to run. | |||
| 101 | ModuleHookFn LinkerHook = Hook; | |||
| 102 | Hook = [=](unsigned Task, const Module &M) { | |||
| 103 | // If the linker's hook returned false, we need to pass that result | |||
| 104 | // through. | |||
| 105 | if (LinkerHook && !LinkerHook(Task, M)) | |||
| 106 | return false; | |||
| 107 | ||||
| 108 | std::string PathPrefix; | |||
| 109 | // If this is the combined module (not a ThinLTO backend compile) or the | |||
| 110 | // user hasn't requested using the input module's path, emit to a file | |||
| 111 | // named from the provided OutputFileName with the Task ID appended. | |||
| 112 | if (M.getModuleIdentifier() == "ld-temp.o" || !UseInputModulePath) { | |||
| 113 | PathPrefix = OutputFileName; | |||
| 114 | if (Task != (unsigned)-1) | |||
| 115 | PathPrefix += utostr(Task) + "."; | |||
| 116 | } else | |||
| 117 | PathPrefix = M.getModuleIdentifier() + "."; | |||
| 118 | std::string Path = PathPrefix + PathSuffix + ".bc"; | |||
| 119 | std::error_code EC; | |||
| 120 | raw_fd_ostream OS(Path, EC, sys::fs::OpenFlags::OF_None); | |||
| 121 | // Because -save-temps is a debugging feature, we report the error | |||
| 122 | // directly and exit. | |||
| 123 | if (EC) | |||
| 124 | reportOpenError(Path, EC.message()); | |||
| 125 | WriteBitcodeToFile(M, OS, /*ShouldPreserveUseListOrder=*/false); | |||
| 126 | return true; | |||
| 127 | }; | |||
| 128 | }; | |||
| 129 | ||||
| 130 | setHook("0.preopt", PreOptModuleHook); | |||
| 131 | setHook("1.promote", PostPromoteModuleHook); | |||
| 132 | setHook("2.internalize", PostInternalizeModuleHook); | |||
| 133 | setHook("3.import", PostImportModuleHook); | |||
| 134 | setHook("4.opt", PostOptModuleHook); | |||
| 135 | setHook("5.precodegen", PreCodeGenModuleHook); | |||
| 136 | ||||
| 137 | CombinedIndexHook = | |||
| 138 | [=](const ModuleSummaryIndex &Index, | |||
| 139 | const DenseSet<GlobalValue::GUID> &GUIDPreservedSymbols) { | |||
| 140 | std::string Path = OutputFileName + "index.bc"; | |||
| 141 | std::error_code EC; | |||
| 142 | raw_fd_ostream OS(Path, EC, sys::fs::OpenFlags::OF_None); | |||
| 143 | // Because -save-temps is a debugging feature, we report the error | |||
| 144 | // directly and exit. | |||
| 145 | if (EC) | |||
| 146 | reportOpenError(Path, EC.message()); | |||
| 147 | WriteIndexToFile(Index, OS); | |||
| 148 | ||||
| 149 | Path = OutputFileName + "index.dot"; | |||
| 150 | raw_fd_ostream OSDot(Path, EC, sys::fs::OpenFlags::OF_None); | |||
| 151 | if (EC) | |||
| 152 | reportOpenError(Path, EC.message()); | |||
| 153 | Index.exportToDot(OSDot, GUIDPreservedSymbols); | |||
| 154 | return true; | |||
| 155 | }; | |||
| 156 | ||||
| 157 | return Error::success(); | |||
| 158 | } | |||
| 159 | ||||
| 160 | #define HANDLE_EXTENSION(Ext) \ | |||
| 161 | llvm::PassPluginLibraryInfo get##Ext##PluginInfo(); | |||
| 162 | #include "llvm/Support/Extension.def" | |||
| 163 | ||||
| 164 | static void RegisterPassPlugins(ArrayRef<std::string> PassPlugins, | |||
| 165 | PassBuilder &PB) { | |||
| 166 | #define HANDLE_EXTENSION(Ext) \ | |||
| 167 | get##Ext##PluginInfo().RegisterPassBuilderCallbacks(PB); | |||
| 168 | #include "llvm/Support/Extension.def" | |||
| 169 | ||||
| 170 | // Load requested pass plugins and let them register pass builder callbacks | |||
| 171 | for (auto &PluginFN : PassPlugins) { | |||
| 172 | auto PassPlugin = PassPlugin::Load(PluginFN); | |||
| 173 | if (!PassPlugin) { | |||
| 174 | errs() << "Failed to load passes from '" << PluginFN | |||
| 175 | << "'. Request ignored.\n"; | |||
| 176 | continue; | |||
| 177 | } | |||
| 178 | ||||
| 179 | PassPlugin->registerPassBuilderCallbacks(PB); | |||
| 180 | } | |||
| 181 | } | |||
| 182 | ||||
| 183 | static std::unique_ptr<TargetMachine> | |||
| 184 | createTargetMachine(const Config &Conf, const Target *TheTarget, Module &M) { | |||
| 185 | StringRef TheTriple = M.getTargetTriple(); | |||
| 186 | SubtargetFeatures Features; | |||
| 187 | Features.getDefaultSubtargetFeatures(Triple(TheTriple)); | |||
| 188 | for (const std::string &A : Conf.MAttrs) | |||
| 189 | Features.AddFeature(A); | |||
| 190 | ||||
| 191 | Optional<Reloc::Model> RelocModel = None; | |||
| 192 | if (Conf.RelocModel) | |||
| 193 | RelocModel = *Conf.RelocModel; | |||
| 194 | else if (M.getModuleFlag("PIC Level")) | |||
| 195 | RelocModel = | |||
| 196 | M.getPICLevel() == PICLevel::NotPIC ? Reloc::Static : Reloc::PIC_; | |||
| 197 | ||||
| 198 | Optional<CodeModel::Model> CodeModel; | |||
| 199 | if (Conf.CodeModel) | |||
| 200 | CodeModel = *Conf.CodeModel; | |||
| 201 | else | |||
| 202 | CodeModel = M.getCodeModel(); | |||
| 203 | ||||
| 204 | std::unique_ptr<TargetMachine> TM(TheTarget->createTargetMachine( | |||
| 205 | TheTriple, Conf.CPU, Features.getString(), Conf.Options, RelocModel, | |||
| 206 | CodeModel, Conf.CGOptLevel)); | |||
| 207 | assert(TM && "Failed to create target machine")(static_cast <bool> (TM && "Failed to create target machine" ) ? void (0) : __assert_fail ("TM && \"Failed to create target machine\"" , "llvm/lib/LTO/LTOBackend.cpp", 207, __extension__ __PRETTY_FUNCTION__ )); | |||
| 208 | return TM; | |||
| 209 | } | |||
| 210 | ||||
| 211 | static void runNewPMPasses(const Config &Conf, Module &Mod, TargetMachine *TM, | |||
| 212 | unsigned OptLevel, bool IsThinLTO, | |||
| 213 | ModuleSummaryIndex *ExportSummary, | |||
| 214 | const ModuleSummaryIndex *ImportSummary) { | |||
| 215 | Optional<PGOOptions> PGOOpt; | |||
| 216 | if (!Conf.SampleProfile.empty()) | |||
| 217 | PGOOpt = PGOOptions(Conf.SampleProfile, "", Conf.ProfileRemapping, | |||
| 218 | PGOOptions::SampleUse, PGOOptions::NoCSAction, true); | |||
| 219 | else if (Conf.RunCSIRInstr) { | |||
| 220 | PGOOpt = PGOOptions("", Conf.CSIRProfile, Conf.ProfileRemapping, | |||
| 221 | PGOOptions::IRUse, PGOOptions::CSIRInstr, | |||
| 222 | Conf.AddFSDiscriminator); | |||
| 223 | } else if (!Conf.CSIRProfile.empty()) { | |||
| 224 | PGOOpt = PGOOptions(Conf.CSIRProfile, "", Conf.ProfileRemapping, | |||
| 225 | PGOOptions::IRUse, PGOOptions::CSIRUse, | |||
| 226 | Conf.AddFSDiscriminator); | |||
| 227 | NoPGOWarnMismatch = !Conf.PGOWarnMismatch; | |||
| 228 | } else if (Conf.AddFSDiscriminator) { | |||
| 229 | PGOOpt = PGOOptions("", "", "", PGOOptions::NoAction, | |||
| 230 | PGOOptions::NoCSAction, true); | |||
| 231 | } | |||
| 232 | if (TM) | |||
| 233 | TM->setPGOOption(PGOOpt); | |||
| 234 | ||||
| 235 | LoopAnalysisManager LAM; | |||
| 236 | FunctionAnalysisManager FAM; | |||
| 237 | CGSCCAnalysisManager CGAM; | |||
| 238 | ModuleAnalysisManager MAM; | |||
| 239 | ||||
| 240 | PassInstrumentationCallbacks PIC; | |||
| 241 | StandardInstrumentations SI(Conf.DebugPassManager); | |||
| 242 | SI.registerCallbacks(PIC, &FAM); | |||
| 243 | PassBuilder PB(TM, Conf.PTO, PGOOpt, &PIC); | |||
| 244 | ||||
| 245 | RegisterPassPlugins(Conf.PassPlugins, PB); | |||
| 246 | ||||
| 247 | std::unique_ptr<TargetLibraryInfoImpl> TLII( | |||
| 248 | new TargetLibraryInfoImpl(Triple(TM->getTargetTriple()))); | |||
| ||||
| 249 | if (Conf.Freestanding) | |||
| 250 | TLII->disableAllFunctions(); | |||
| 251 | FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); }); | |||
| 252 | ||||
| 253 | // Parse a custom AA pipeline if asked to. | |||
| 254 | if (!Conf.AAPipeline.empty()) { | |||
| 255 | AAManager AA; | |||
| 256 | if (auto Err = PB.parseAAPipeline(AA, Conf.AAPipeline)) { | |||
| 257 | report_fatal_error(Twine("unable to parse AA pipeline description '") + | |||
| 258 | Conf.AAPipeline + "': " + toString(std::move(Err))); | |||
| 259 | } | |||
| 260 | // Register the AA manager first so that our version is the one used. | |||
| 261 | FAM.registerPass([&] { return std::move(AA); }); | |||
| 262 | } | |||
| 263 | ||||
| 264 | // Register all the basic analyses with the managers. | |||
| 265 | PB.registerModuleAnalyses(MAM); | |||
| 266 | PB.registerCGSCCAnalyses(CGAM); | |||
| 267 | PB.registerFunctionAnalyses(FAM); | |||
| 268 | PB.registerLoopAnalyses(LAM); | |||
| 269 | PB.crossRegisterProxies(LAM, FAM, CGAM, MAM); | |||
| 270 | ||||
| 271 | ModulePassManager MPM; | |||
| 272 | ||||
| 273 | if (!Conf.DisableVerify) | |||
| 274 | MPM.addPass(VerifierPass()); | |||
| 275 | ||||
| 276 | OptimizationLevel OL; | |||
| 277 | ||||
| 278 | switch (OptLevel) { | |||
| 279 | default: | |||
| 280 | llvm_unreachable("Invalid optimization level")::llvm::llvm_unreachable_internal("Invalid optimization level" , "llvm/lib/LTO/LTOBackend.cpp", 280); | |||
| 281 | case 0: | |||
| 282 | OL = OptimizationLevel::O0; | |||
| 283 | break; | |||
| 284 | case 1: | |||
| 285 | OL = OptimizationLevel::O1; | |||
| 286 | break; | |||
| 287 | case 2: | |||
| 288 | OL = OptimizationLevel::O2; | |||
| 289 | break; | |||
| 290 | case 3: | |||
| 291 | OL = OptimizationLevel::O3; | |||
| 292 | break; | |||
| 293 | } | |||
| 294 | ||||
| 295 | // Parse a custom pipeline if asked to. | |||
| 296 | if (!Conf.OptPipeline.empty()) { | |||
| 297 | if (auto Err = PB.parsePassPipeline(MPM, Conf.OptPipeline)) { | |||
| 298 | report_fatal_error(Twine("unable to parse pass pipeline description '") + | |||
| 299 | Conf.OptPipeline + "': " + toString(std::move(Err))); | |||
| 300 | } | |||
| 301 | } else if (IsThinLTO) { | |||
| 302 | MPM.addPass(PB.buildThinLTODefaultPipeline(OL, ImportSummary)); | |||
| 303 | } else { | |||
| 304 | MPM.addPass(PB.buildLTODefaultPipeline(OL, ExportSummary)); | |||
| 305 | } | |||
| 306 | ||||
| 307 | if (!Conf.DisableVerify) | |||
| 308 | MPM.addPass(VerifierPass()); | |||
| 309 | ||||
| 310 | MPM.run(Mod, MAM); | |||
| 311 | } | |||
| 312 | ||||
| 313 | static void runOldPMPasses(const Config &Conf, Module &Mod, TargetMachine *TM, | |||
| 314 | bool IsThinLTO, ModuleSummaryIndex *ExportSummary, | |||
| 315 | const ModuleSummaryIndex *ImportSummary) { | |||
| 316 | legacy::PassManager passes; | |||
| 317 | passes.add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis())); | |||
| 318 | ||||
| 319 | PassManagerBuilder PMB; | |||
| 320 | PMB.LibraryInfo = new TargetLibraryInfoImpl(Triple(TM->getTargetTriple())); | |||
| 321 | if (Conf.Freestanding) | |||
| 322 | PMB.LibraryInfo->disableAllFunctions(); | |||
| 323 | PMB.Inliner = createFunctionInliningPass(); | |||
| 324 | PMB.ExportSummary = ExportSummary; | |||
| 325 | PMB.ImportSummary = ImportSummary; | |||
| 326 | // Unconditionally verify input since it is not verified before this | |||
| 327 | // point and has unknown origin. | |||
| 328 | PMB.VerifyInput = true; | |||
| 329 | PMB.VerifyOutput = !Conf.DisableVerify; | |||
| 330 | PMB.LoopVectorize = true; | |||
| 331 | PMB.SLPVectorize = true; | |||
| 332 | PMB.OptLevel = Conf.OptLevel; | |||
| 333 | PMB.PGOSampleUse = Conf.SampleProfile; | |||
| 334 | PMB.EnablePGOCSInstrGen = Conf.RunCSIRInstr; | |||
| 335 | if (!Conf.RunCSIRInstr && !Conf.CSIRProfile.empty()) { | |||
| 336 | PMB.EnablePGOCSInstrUse = true; | |||
| 337 | PMB.PGOInstrUse = Conf.CSIRProfile; | |||
| 338 | } | |||
| 339 | if (IsThinLTO) | |||
| 340 | PMB.populateThinLTOPassManager(passes); | |||
| 341 | else | |||
| 342 | PMB.populateLTOPassManager(passes); | |||
| 343 | passes.run(Mod); | |||
| 344 | } | |||
| 345 | ||||
| 346 | bool lto::opt(const Config &Conf, TargetMachine *TM, unsigned Task, Module &Mod, | |||
| 347 | bool IsThinLTO, ModuleSummaryIndex *ExportSummary, | |||
| 348 | const ModuleSummaryIndex *ImportSummary, | |||
| 349 | const std::vector<uint8_t> &CmdArgs) { | |||
| 350 | if (EmbedBitcode == LTOBitcodeEmbedding::EmbedPostMergePreOptimized) { | |||
| 351 | // FIXME: the motivation for capturing post-merge bitcode and command line | |||
| 352 | // is replicating the compilation environment from bitcode, without needing | |||
| 353 | // to understand the dependencies (the functions to be imported). This | |||
| 354 | // assumes a clang - based invocation, case in which we have the command | |||
| 355 | // line. | |||
| 356 | // It's not very clear how the above motivation would map in the | |||
| 357 | // linker-based case, so we currently don't plumb the command line args in | |||
| 358 | // that case. | |||
| 359 | if (CmdArgs.empty()) | |||
| 360 | LLVM_DEBUG(do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("lto-backend")) { dbgs() << "Post-(Thin)LTO merge bitcode embedding was requested, but " "command line arguments are not available"; } } while (false ) | |||
| 361 | dbgs() << "Post-(Thin)LTO merge bitcode embedding was requested, but "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("lto-backend")) { dbgs() << "Post-(Thin)LTO merge bitcode embedding was requested, but " "command line arguments are not available"; } } while (false ) | |||
| 362 | "command line arguments are not available")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType ("lto-backend")) { dbgs() << "Post-(Thin)LTO merge bitcode embedding was requested, but " "command line arguments are not available"; } } while (false ); | |||
| 363 | llvm::EmbedBitcodeInModule(Mod, llvm::MemoryBufferRef(), | |||
| 364 | /*EmbedBitcode*/ true, /*EmbedCmdline*/ true, | |||
| 365 | /*Cmdline*/ CmdArgs); | |||
| 366 | } | |||
| 367 | // FIXME: Plumb the combined index into the new pass manager. | |||
| 368 | if (Conf.UseNewPM || !Conf.OptPipeline.empty()) { | |||
| 369 | runNewPMPasses(Conf, Mod, TM, Conf.OptLevel, IsThinLTO, ExportSummary, | |||
| 370 | ImportSummary); | |||
| 371 | } else { | |||
| 372 | runOldPMPasses(Conf, Mod, TM, IsThinLTO, ExportSummary, ImportSummary); | |||
| 373 | } | |||
| 374 | return !Conf.PostOptModuleHook || Conf.PostOptModuleHook(Task, Mod); | |||
| 375 | } | |||
| 376 | ||||
| 377 | static void codegen(const Config &Conf, TargetMachine *TM, | |||
| 378 | AddStreamFn AddStream, unsigned Task, Module &Mod, | |||
| 379 | const ModuleSummaryIndex &CombinedIndex) { | |||
| 380 | if (Conf.PreCodeGenModuleHook && !Conf.PreCodeGenModuleHook(Task, Mod)) | |||
| 381 | return; | |||
| 382 | ||||
| 383 | if (EmbedBitcode == LTOBitcodeEmbedding::EmbedOptimized) | |||
| 384 | llvm::EmbedBitcodeInModule(Mod, llvm::MemoryBufferRef(), | |||
| 385 | /*EmbedBitcode*/ true, | |||
| 386 | /*EmbedCmdline*/ false, | |||
| 387 | /*CmdArgs*/ std::vector<uint8_t>()); | |||
| 388 | ||||
| 389 | std::unique_ptr<ToolOutputFile> DwoOut; | |||
| 390 | SmallString<1024> DwoFile(Conf.SplitDwarfOutput); | |||
| 391 | if (!Conf.DwoDir.empty()) { | |||
| 392 | std::error_code EC; | |||
| 393 | if (auto EC = llvm::sys::fs::create_directories(Conf.DwoDir)) | |||
| 394 | report_fatal_error(Twine("Failed to create directory ") + Conf.DwoDir + | |||
| 395 | ": " + EC.message()); | |||
| 396 | ||||
| 397 | DwoFile = Conf.DwoDir; | |||
| 398 | sys::path::append(DwoFile, std::to_string(Task) + ".dwo"); | |||
| 399 | TM->Options.MCOptions.SplitDwarfFile = std::string(DwoFile); | |||
| 400 | } else | |||
| 401 | TM->Options.MCOptions.SplitDwarfFile = Conf.SplitDwarfFile; | |||
| 402 | ||||
| 403 | if (!DwoFile.empty()) { | |||
| 404 | std::error_code EC; | |||
| 405 | DwoOut = std::make_unique<ToolOutputFile>(DwoFile, EC, sys::fs::OF_None); | |||
| 406 | if (EC) | |||
| 407 | report_fatal_error(Twine("Failed to open ") + DwoFile + ": " + | |||
| 408 | EC.message()); | |||
| 409 | } | |||
| 410 | ||||
| 411 | Expected<std::unique_ptr<CachedFileStream>> StreamOrErr = AddStream(Task); | |||
| 412 | if (Error Err = StreamOrErr.takeError()) | |||
| 413 | report_fatal_error(std::move(Err)); | |||
| 414 | std::unique_ptr<CachedFileStream> &Stream = *StreamOrErr; | |||
| 415 | TM->Options.ObjectFilenameForDebug = Stream->ObjectPathName; | |||
| 416 | ||||
| 417 | legacy::PassManager CodeGenPasses; | |||
| 418 | TargetLibraryInfoImpl TLII(Triple(Mod.getTargetTriple())); | |||
| 419 | CodeGenPasses.add(new TargetLibraryInfoWrapperPass(TLII)); | |||
| 420 | CodeGenPasses.add( | |||
| 421 | createImmutableModuleSummaryIndexWrapperPass(&CombinedIndex)); | |||
| 422 | if (Conf.PreCodeGenPassesHook) | |||
| 423 | Conf.PreCodeGenPassesHook(CodeGenPasses); | |||
| 424 | if (TM->addPassesToEmitFile(CodeGenPasses, *Stream->OS, | |||
| 425 | DwoOut ? &DwoOut->os() : nullptr, | |||
| 426 | Conf.CGFileType)) | |||
| 427 | report_fatal_error("Failed to setup codegen"); | |||
| 428 | CodeGenPasses.run(Mod); | |||
| 429 | ||||
| 430 | if (DwoOut) | |||
| 431 | DwoOut->keep(); | |||
| 432 | } | |||
| 433 | ||||
| 434 | static void splitCodeGen(const Config &C, TargetMachine *TM, | |||
| 435 | AddStreamFn AddStream, | |||
| 436 | unsigned ParallelCodeGenParallelismLevel, Module &Mod, | |||
| 437 | const ModuleSummaryIndex &CombinedIndex) { | |||
| 438 | ThreadPool CodegenThreadPool( | |||
| 439 | heavyweight_hardware_concurrency(ParallelCodeGenParallelismLevel)); | |||
| 440 | unsigned ThreadCount = 0; | |||
| 441 | const Target *T = &TM->getTarget(); | |||
| 442 | ||||
| 443 | SplitModule( | |||
| 444 | Mod, ParallelCodeGenParallelismLevel, | |||
| 445 | [&](std::unique_ptr<Module> MPart) { | |||
| 446 | // We want to clone the module in a new context to multi-thread the | |||
| 447 | // codegen. We do it by serializing partition modules to bitcode | |||
| 448 | // (while still on the main thread, in order to avoid data races) and | |||
| 449 | // spinning up new threads which deserialize the partitions into | |||
| 450 | // separate contexts. | |||
| 451 | // FIXME: Provide a more direct way to do this in LLVM. | |||
| 452 | SmallString<0> BC; | |||
| 453 | raw_svector_ostream BCOS(BC); | |||
| 454 | WriteBitcodeToFile(*MPart, BCOS); | |||
| 455 | ||||
| 456 | // Enqueue the task | |||
| 457 | CodegenThreadPool.async( | |||
| 458 | [&](const SmallString<0> &BC, unsigned ThreadId) { | |||
| 459 | LTOLLVMContext Ctx(C); | |||
| 460 | Expected<std::unique_ptr<Module>> MOrErr = parseBitcodeFile( | |||
| 461 | MemoryBufferRef(StringRef(BC.data(), BC.size()), "ld-temp.o"), | |||
| 462 | Ctx); | |||
| 463 | if (!MOrErr) | |||
| 464 | report_fatal_error("Failed to read bitcode"); | |||
| 465 | std::unique_ptr<Module> MPartInCtx = std::move(MOrErr.get()); | |||
| 466 | ||||
| 467 | std::unique_ptr<TargetMachine> TM = | |||
| 468 | createTargetMachine(C, T, *MPartInCtx); | |||
| 469 | ||||
| 470 | codegen(C, TM.get(), AddStream, ThreadId, *MPartInCtx, | |||
| 471 | CombinedIndex); | |||
| 472 | }, | |||
| 473 | // Pass BC using std::move to ensure that it get moved rather than | |||
| 474 | // copied into the thread's context. | |||
| 475 | std::move(BC), ThreadCount++); | |||
| 476 | }, | |||
| 477 | false); | |||
| 478 | ||||
| 479 | // Because the inner lambda (which runs in a worker thread) captures our local | |||
| 480 | // variables, we need to wait for the worker threads to terminate before we | |||
| 481 | // can leave the function scope. | |||
| 482 | CodegenThreadPool.wait(); | |||
| 483 | } | |||
| 484 | ||||
| 485 | static Expected<const Target *> initAndLookupTarget(const Config &C, | |||
| 486 | Module &Mod) { | |||
| 487 | if (!C.OverrideTriple.empty()) | |||
| 488 | Mod.setTargetTriple(C.OverrideTriple); | |||
| 489 | else if (Mod.getTargetTriple().empty()) | |||
| 490 | Mod.setTargetTriple(C.DefaultTriple); | |||
| 491 | ||||
| 492 | std::string Msg; | |||
| 493 | const Target *T = TargetRegistry::lookupTarget(Mod.getTargetTriple(), Msg); | |||
| 494 | if (!T) | |||
| 495 | return make_error<StringError>(Msg, inconvertibleErrorCode()); | |||
| 496 | return T; | |||
| 497 | } | |||
| 498 | ||||
| 499 | Error lto::finalizeOptimizationRemarks( | |||
| 500 | std::unique_ptr<ToolOutputFile> DiagOutputFile) { | |||
| 501 | // Make sure we flush the diagnostic remarks file in case the linker doesn't | |||
| 502 | // call the global destructors before exiting. | |||
| 503 | if (!DiagOutputFile) | |||
| 504 | return Error::success(); | |||
| 505 | DiagOutputFile->keep(); | |||
| 506 | DiagOutputFile->os().flush(); | |||
| 507 | return Error::success(); | |||
| 508 | } | |||
| 509 | ||||
| 510 | Error lto::backend(const Config &C, AddStreamFn AddStream, | |||
| 511 | unsigned ParallelCodeGenParallelismLevel, Module &Mod, | |||
| 512 | ModuleSummaryIndex &CombinedIndex) { | |||
| 513 | Expected<const Target *> TOrErr = initAndLookupTarget(C, Mod); | |||
| 514 | if (!TOrErr) | |||
| ||||
| 515 | return TOrErr.takeError(); | |||
| 516 | ||||
| 517 | std::unique_ptr<TargetMachine> TM = createTargetMachine(C, *TOrErr, Mod); | |||
| 518 | ||||
| 519 | if (!C.CodeGenOnly) { | |||
| 520 | if (!opt(C, TM.get(), 0, Mod, /*IsThinLTO=*/false, | |||
| 521 | /*ExportSummary=*/&CombinedIndex, /*ImportSummary=*/nullptr, | |||
| 522 | /*CmdArgs*/ std::vector<uint8_t>())) | |||
| 523 | return Error::success(); | |||
| 524 | } | |||
| 525 | ||||
| 526 | if (ParallelCodeGenParallelismLevel == 1) { | |||
| 527 | codegen(C, TM.get(), AddStream, 0, Mod, CombinedIndex); | |||
| 528 | } else { | |||
| 529 | splitCodeGen(C, TM.get(), AddStream, ParallelCodeGenParallelismLevel, Mod, | |||
| 530 | CombinedIndex); | |||
| 531 | } | |||
| 532 | return Error::success(); | |||
| 533 | } | |||
| 534 | ||||
| 535 | static void dropDeadSymbols(Module &Mod, const GVSummaryMapTy &DefinedGlobals, | |||
| 536 | const ModuleSummaryIndex &Index) { | |||
| 537 | std::vector<GlobalValue*> DeadGVs; | |||
| 538 | for (auto &GV : Mod.global_values()) | |||
| 539 | if (GlobalValueSummary *GVS = DefinedGlobals.lookup(GV.getGUID())) | |||
| 540 | if (!Index.isGlobalValueLive(GVS)) { | |||
| 541 | DeadGVs.push_back(&GV); | |||
| 542 | convertToDeclaration(GV); | |||
| 543 | } | |||
| 544 | ||||
| 545 | // Now that all dead bodies have been dropped, delete the actual objects | |||
| 546 | // themselves when possible. | |||
| 547 | for (GlobalValue *GV : DeadGVs) { | |||
| 548 | GV->removeDeadConstantUsers(); | |||
| 549 | // Might reference something defined in native object (i.e. dropped a | |||
| 550 | // non-prevailing IR def, but we need to keep the declaration). | |||
| 551 | if (GV->use_empty()) | |||
| 552 | GV->eraseFromParent(); | |||
| 553 | } | |||
| 554 | } | |||
| 555 | ||||
| 556 | Error lto::thinBackend(const Config &Conf, unsigned Task, AddStreamFn AddStream, | |||
| 557 | Module &Mod, const ModuleSummaryIndex &CombinedIndex, | |||
| 558 | const FunctionImporter::ImportMapTy &ImportList, | |||
| 559 | const GVSummaryMapTy &DefinedGlobals, | |||
| 560 | MapVector<StringRef, BitcodeModule> *ModuleMap, | |||
| 561 | const std::vector<uint8_t> &CmdArgs) { | |||
| 562 | Expected<const Target *> TOrErr = initAndLookupTarget(Conf, Mod); | |||
| 563 | if (!TOrErr) | |||
| 564 | return TOrErr.takeError(); | |||
| 565 | ||||
| 566 | std::unique_ptr<TargetMachine> TM = createTargetMachine(Conf, *TOrErr, Mod); | |||
| 567 | ||||
| 568 | // Setup optimization remarks. | |||
| 569 | auto DiagFileOrErr = lto::setupLLVMOptimizationRemarks( | |||
| 570 | Mod.getContext(), Conf.RemarksFilename, Conf.RemarksPasses, | |||
| 571 | Conf.RemarksFormat, Conf.RemarksWithHotness, Conf.RemarksHotnessThreshold, | |||
| 572 | Task); | |||
| 573 | if (!DiagFileOrErr) | |||
| 574 | return DiagFileOrErr.takeError(); | |||
| 575 | auto DiagnosticOutputFile = std::move(*DiagFileOrErr); | |||
| 576 | ||||
| 577 | // Set the partial sample profile ratio in the profile summary module flag of | |||
| 578 | // the module, if applicable. | |||
| 579 | Mod.setPartialSampleProfileRatio(CombinedIndex); | |||
| 580 | ||||
| 581 | if (Conf.CodeGenOnly) { | |||
| 582 | codegen(Conf, TM.get(), AddStream, Task, Mod, CombinedIndex); | |||
| 583 | return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); | |||
| 584 | } | |||
| 585 | ||||
| 586 | if (Conf.PreOptModuleHook && !Conf.PreOptModuleHook(Task, Mod)) | |||
| 587 | return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); | |||
| 588 | ||||
| 589 | auto OptimizeAndCodegen = | |||
| 590 | [&](Module &Mod, TargetMachine *TM, | |||
| 591 | std::unique_ptr<ToolOutputFile> DiagnosticOutputFile) { | |||
| 592 | if (!opt(Conf, TM, Task, Mod, /*IsThinLTO=*/true, | |||
| 593 | /*ExportSummary=*/nullptr, /*ImportSummary=*/&CombinedIndex, | |||
| 594 | CmdArgs)) | |||
| 595 | return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); | |||
| 596 | ||||
| 597 | codegen(Conf, TM, AddStream, Task, Mod, CombinedIndex); | |||
| 598 | return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); | |||
| 599 | }; | |||
| 600 | ||||
| 601 | if (ThinLTOAssumeMerged) | |||
| 602 | return OptimizeAndCodegen(Mod, TM.get(), std::move(DiagnosticOutputFile)); | |||
| 603 | ||||
| 604 | // When linking an ELF shared object, dso_local should be dropped. We | |||
| 605 | // conservatively do this for -fpic. | |||
| 606 | bool ClearDSOLocalOnDeclarations = | |||
| 607 | TM->getTargetTriple().isOSBinFormatELF() && | |||
| 608 | TM->getRelocationModel() != Reloc::Static && | |||
| 609 | Mod.getPIELevel() == PIELevel::Default; | |||
| 610 | renameModuleForThinLTO(Mod, CombinedIndex, ClearDSOLocalOnDeclarations); | |||
| 611 | ||||
| 612 | dropDeadSymbols(Mod, DefinedGlobals, CombinedIndex); | |||
| 613 | ||||
| 614 | thinLTOFinalizeInModule(Mod, DefinedGlobals, /*PropagateAttrs=*/true); | |||
| 615 | ||||
| 616 | if (Conf.PostPromoteModuleHook && !Conf.PostPromoteModuleHook(Task, Mod)) | |||
| 617 | return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); | |||
| 618 | ||||
| 619 | if (!DefinedGlobals.empty()) | |||
| 620 | thinLTOInternalizeModule(Mod, DefinedGlobals); | |||
| 621 | ||||
| 622 | if (Conf.PostInternalizeModuleHook && | |||
| 623 | !Conf.PostInternalizeModuleHook(Task, Mod)) | |||
| 624 | return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); | |||
| 625 | ||||
| 626 | auto ModuleLoader = [&](StringRef Identifier) { | |||
| 627 | assert(Mod.getContext().isODRUniquingDebugTypes() &&(static_cast <bool> (Mod.getContext().isODRUniquingDebugTypes () && "ODR Type uniquing should be enabled on the context" ) ? void (0) : __assert_fail ("Mod.getContext().isODRUniquingDebugTypes() && \"ODR Type uniquing should be enabled on the context\"" , "llvm/lib/LTO/LTOBackend.cpp", 628, __extension__ __PRETTY_FUNCTION__ )) | |||
| 628 | "ODR Type uniquing should be enabled on the context")(static_cast <bool> (Mod.getContext().isODRUniquingDebugTypes () && "ODR Type uniquing should be enabled on the context" ) ? void (0) : __assert_fail ("Mod.getContext().isODRUniquingDebugTypes() && \"ODR Type uniquing should be enabled on the context\"" , "llvm/lib/LTO/LTOBackend.cpp", 628, __extension__ __PRETTY_FUNCTION__ )); | |||
| 629 | if (ModuleMap) { | |||
| 630 | auto I = ModuleMap->find(Identifier); | |||
| 631 | assert(I != ModuleMap->end())(static_cast <bool> (I != ModuleMap->end()) ? void ( 0) : __assert_fail ("I != ModuleMap->end()", "llvm/lib/LTO/LTOBackend.cpp" , 631, __extension__ __PRETTY_FUNCTION__)); | |||
| 632 | return I->second.getLazyModule(Mod.getContext(), | |||
| 633 | /*ShouldLazyLoadMetadata=*/true, | |||
| 634 | /*IsImporting*/ true); | |||
| 635 | } | |||
| 636 | ||||
| 637 | ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MBOrErr = | |||
| 638 | llvm::MemoryBuffer::getFile(Identifier); | |||
| 639 | if (!MBOrErr) | |||
| 640 | return Expected<std::unique_ptr<llvm::Module>>(make_error<StringError>( | |||
| 641 | Twine("Error loading imported file ") + Identifier + " : ", | |||
| 642 | MBOrErr.getError())); | |||
| 643 | ||||
| 644 | Expected<BitcodeModule> BMOrErr = findThinLTOModule(**MBOrErr); | |||
| 645 | if (!BMOrErr) | |||
| 646 | return Expected<std::unique_ptr<llvm::Module>>(make_error<StringError>( | |||
| 647 | Twine("Error loading imported file ") + Identifier + " : " + | |||
| 648 | toString(BMOrErr.takeError()), | |||
| 649 | inconvertibleErrorCode())); | |||
| 650 | ||||
| 651 | Expected<std::unique_ptr<Module>> MOrErr = | |||
| 652 | BMOrErr->getLazyModule(Mod.getContext(), | |||
| 653 | /*ShouldLazyLoadMetadata=*/true, | |||
| 654 | /*IsImporting*/ true); | |||
| 655 | if (MOrErr) | |||
| 656 | (*MOrErr)->setOwnedMemoryBuffer(std::move(*MBOrErr)); | |||
| 657 | return MOrErr; | |||
| 658 | }; | |||
| 659 | ||||
| 660 | FunctionImporter Importer(CombinedIndex, ModuleLoader, | |||
| 661 | ClearDSOLocalOnDeclarations); | |||
| 662 | if (Error Err = Importer.importFunctions(Mod, ImportList).takeError()) | |||
| 663 | return Err; | |||
| 664 | ||||
| 665 | if (Conf.PostImportModuleHook && !Conf.PostImportModuleHook(Task, Mod)) | |||
| 666 | return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); | |||
| 667 | ||||
| 668 | return OptimizeAndCodegen(Mod, TM.get(), std::move(DiagnosticOutputFile)); | |||
| 669 | } | |||
| 670 | ||||
| 671 | BitcodeModule *lto::findThinLTOModule(MutableArrayRef<BitcodeModule> BMs) { | |||
| 672 | if (ThinLTOAssumeMerged && BMs.size() == 1) | |||
| 673 | return BMs.begin(); | |||
| 674 | ||||
| 675 | for (BitcodeModule &BM : BMs) { | |||
| 676 | Expected<BitcodeLTOInfo> LTOInfo = BM.getLTOInfo(); | |||
| 677 | if (LTOInfo && LTOInfo->IsThinLTO) | |||
| 678 | return &BM; | |||
| 679 | } | |||
| 680 | return nullptr; | |||
| 681 | } | |||
| 682 | ||||
| 683 | Expected<BitcodeModule> lto::findThinLTOModule(MemoryBufferRef MBRef) { | |||
| 684 | Expected<std::vector<BitcodeModule>> BMsOrErr = getBitcodeModuleList(MBRef); | |||
| 685 | if (!BMsOrErr) | |||
| 686 | return BMsOrErr.takeError(); | |||
| 687 | ||||
| 688 | // The bitcode file may contain multiple modules, we want the one that is | |||
| 689 | // marked as being the ThinLTO module. | |||
| 690 | if (const BitcodeModule *Bm = lto::findThinLTOModule(*BMsOrErr)) | |||
| 691 | return *Bm; | |||
| 692 | ||||
| 693 | return make_error<StringError>("Could not find module summary", | |||
| 694 | inconvertibleErrorCode()); | |||
| 695 | } | |||
| 696 | ||||
| 697 | bool lto::initImportList(const Module &M, | |||
| 698 | const ModuleSummaryIndex &CombinedIndex, | |||
| 699 | FunctionImporter::ImportMapTy &ImportList) { | |||
| 700 | if (ThinLTOAssumeMerged) | |||
| 701 | return true; | |||
| 702 | // We can simply import the values mentioned in the combined index, since | |||
| 703 | // we should only invoke this using the individual indexes written out | |||
| 704 | // via a WriteIndexesThinBackend. | |||
| 705 | for (const auto &GlobalList : CombinedIndex) { | |||
| 706 | // Ignore entries for undefined references. | |||
| 707 | if (GlobalList.second.SummaryList.empty()) | |||
| 708 | continue; | |||
| 709 | ||||
| 710 | auto GUID = GlobalList.first; | |||
| 711 | for (const auto &Summary : GlobalList.second.SummaryList) { | |||
| 712 | // Skip the summaries for the importing module. These are included to | |||
| 713 | // e.g. record required linkage changes. | |||
| 714 | if (Summary->modulePath() == M.getModuleIdentifier()) | |||
| 715 | continue; | |||
| 716 | // Add an entry to provoke importing by thinBackend. | |||
| 717 | ImportList[Summary->modulePath()].insert(GUID); | |||
| 718 | } | |||
| 719 | } | |||
| 720 | return true; | |||
| 721 | } |
| 1 | //===- llvm/Support/Error.h - Recoverable error handling --------*- C++ -*-===// |
| 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 file defines an API used to report recoverable errors. |
| 10 | // |
| 11 | //===----------------------------------------------------------------------===// |
| 12 | |
| 13 | #ifndef LLVM_SUPPORT_ERROR_H |
| 14 | #define LLVM_SUPPORT_ERROR_H |
| 15 | |
| 16 | #include "llvm-c/Error.h" |
| 17 | #include "llvm/ADT/STLExtras.h" |
| 18 | #include "llvm/ADT/SmallVector.h" |
| 19 | #include "llvm/ADT/StringExtras.h" |
| 20 | #include "llvm/ADT/Twine.h" |
| 21 | #include "llvm/Config/abi-breaking.h" |
| 22 | #include "llvm/Support/AlignOf.h" |
| 23 | #include "llvm/Support/Compiler.h" |
| 24 | #include "llvm/Support/Debug.h" |
| 25 | #include "llvm/Support/ErrorHandling.h" |
| 26 | #include "llvm/Support/ErrorOr.h" |
| 27 | #include "llvm/Support/Format.h" |
| 28 | #include "llvm/Support/raw_ostream.h" |
| 29 | #include <algorithm> |
| 30 | #include <cassert> |
| 31 | #include <cstdint> |
| 32 | #include <cstdlib> |
| 33 | #include <functional> |
| 34 | #include <memory> |
| 35 | #include <new> |
| 36 | #include <string> |
| 37 | #include <system_error> |
| 38 | #include <type_traits> |
| 39 | #include <utility> |
| 40 | #include <vector> |
| 41 | |
| 42 | namespace llvm { |
| 43 | |
| 44 | class ErrorSuccess; |
| 45 | |
| 46 | /// Base class for error info classes. Do not extend this directly: Extend |
| 47 | /// the ErrorInfo template subclass instead. |
| 48 | class ErrorInfoBase { |
| 49 | public: |
| 50 | virtual ~ErrorInfoBase() = default; |
| 51 | |
| 52 | /// Print an error message to an output stream. |
| 53 | virtual void log(raw_ostream &OS) const = 0; |
| 54 | |
| 55 | /// Return the error message as a string. |
| 56 | virtual std::string message() const { |
| 57 | std::string Msg; |
| 58 | raw_string_ostream OS(Msg); |
| 59 | log(OS); |
| 60 | return OS.str(); |
| 61 | } |
| 62 | |
| 63 | /// Convert this error to a std::error_code. |
| 64 | /// |
| 65 | /// This is a temporary crutch to enable interaction with code still |
| 66 | /// using std::error_code. It will be removed in the future. |
| 67 | virtual std::error_code convertToErrorCode() const = 0; |
| 68 | |
| 69 | // Returns the class ID for this type. |
| 70 | static const void *classID() { return &ID; } |
| 71 | |
| 72 | // Returns the class ID for the dynamic type of this ErrorInfoBase instance. |
| 73 | virtual const void *dynamicClassID() const = 0; |
| 74 | |
| 75 | // Check whether this instance is a subclass of the class identified by |
| 76 | // ClassID. |
| 77 | virtual bool isA(const void *const ClassID) const { |
| 78 | return ClassID == classID(); |
| 79 | } |
| 80 | |
| 81 | // Check whether this instance is a subclass of ErrorInfoT. |
| 82 | template <typename ErrorInfoT> bool isA() const { |
| 83 | return isA(ErrorInfoT::classID()); |
| 84 | } |
| 85 | |
| 86 | private: |
| 87 | virtual void anchor(); |
| 88 | |
| 89 | static char ID; |
| 90 | }; |
| 91 | |
| 92 | /// Lightweight error class with error context and mandatory checking. |
| 93 | /// |
| 94 | /// Instances of this class wrap a ErrorInfoBase pointer. Failure states |
| 95 | /// are represented by setting the pointer to a ErrorInfoBase subclass |
| 96 | /// instance containing information describing the failure. Success is |
| 97 | /// represented by a null pointer value. |
| 98 | /// |
| 99 | /// Instances of Error also contains a 'Checked' flag, which must be set |
| 100 | /// before the destructor is called, otherwise the destructor will trigger a |
| 101 | /// runtime error. This enforces at runtime the requirement that all Error |
| 102 | /// instances be checked or returned to the caller. |
| 103 | /// |
| 104 | /// There are two ways to set the checked flag, depending on what state the |
| 105 | /// Error instance is in. For Error instances indicating success, it |
| 106 | /// is sufficient to invoke the boolean conversion operator. E.g.: |
| 107 | /// |
| 108 | /// @code{.cpp} |
| 109 | /// Error foo(<...>); |
| 110 | /// |
| 111 | /// if (auto E = foo(<...>)) |
| 112 | /// return E; // <- Return E if it is in the error state. |
| 113 | /// // We have verified that E was in the success state. It can now be safely |
| 114 | /// // destroyed. |
| 115 | /// @endcode |
| 116 | /// |
| 117 | /// A success value *can not* be dropped. For example, just calling 'foo(<...>)' |
| 118 | /// without testing the return value will raise a runtime error, even if foo |
| 119 | /// returns success. |
| 120 | /// |
| 121 | /// For Error instances representing failure, you must use either the |
| 122 | /// handleErrors or handleAllErrors function with a typed handler. E.g.: |
| 123 | /// |
| 124 | /// @code{.cpp} |
| 125 | /// class MyErrorInfo : public ErrorInfo<MyErrorInfo> { |
| 126 | /// // Custom error info. |
| 127 | /// }; |
| 128 | /// |
| 129 | /// Error foo(<...>) { return make_error<MyErrorInfo>(...); } |
| 130 | /// |
| 131 | /// auto E = foo(<...>); // <- foo returns failure with MyErrorInfo. |
| 132 | /// auto NewE = |
| 133 | /// handleErrors(E, |
| 134 | /// [](const MyErrorInfo &M) { |
| 135 | /// // Deal with the error. |
| 136 | /// }, |
| 137 | /// [](std::unique_ptr<OtherError> M) -> Error { |
| 138 | /// if (canHandle(*M)) { |
| 139 | /// // handle error. |
| 140 | /// return Error::success(); |
| 141 | /// } |
| 142 | /// // Couldn't handle this error instance. Pass it up the stack. |
| 143 | /// return Error(std::move(M)); |
| 144 | /// ); |
| 145 | /// // Note - we must check or return NewE in case any of the handlers |
| 146 | /// // returned a new error. |
| 147 | /// @endcode |
| 148 | /// |
| 149 | /// The handleAllErrors function is identical to handleErrors, except |
| 150 | /// that it has a void return type, and requires all errors to be handled and |
| 151 | /// no new errors be returned. It prevents errors (assuming they can all be |
| 152 | /// handled) from having to be bubbled all the way to the top-level. |
| 153 | /// |
| 154 | /// *All* Error instances must be checked before destruction, even if |
| 155 | /// they're moved-assigned or constructed from Success values that have already |
| 156 | /// been checked. This enforces checking through all levels of the call stack. |
| 157 | class LLVM_NODISCARD[[clang::warn_unused_result]] Error { |
| 158 | // ErrorList needs to be able to yank ErrorInfoBase pointers out of Errors |
| 159 | // to add to the error list. It can't rely on handleErrors for this, since |
| 160 | // handleErrors does not support ErrorList handlers. |
| 161 | friend class ErrorList; |
| 162 | |
| 163 | // handleErrors needs to be able to set the Checked flag. |
| 164 | template <typename... HandlerTs> |
| 165 | friend Error handleErrors(Error E, HandlerTs &&... Handlers); |
| 166 | |
| 167 | // Expected<T> needs to be able to steal the payload when constructed from an |
| 168 | // error. |
| 169 | template <typename T> friend class Expected; |
| 170 | |
| 171 | // wrap needs to be able to steal the payload. |
| 172 | friend LLVMErrorRef wrap(Error); |
| 173 | |
| 174 | protected: |
| 175 | /// Create a success value. Prefer using 'Error::success()' for readability |
| 176 | Error() { |
| 177 | setPtr(nullptr); |
| 178 | setChecked(false); |
| 179 | } |
| 180 | |
| 181 | public: |
| 182 | /// Create a success value. |
| 183 | static ErrorSuccess success(); |
| 184 | |
| 185 | // Errors are not copy-constructable. |
| 186 | Error(const Error &Other) = delete; |
| 187 | |
| 188 | /// Move-construct an error value. The newly constructed error is considered |
| 189 | /// unchecked, even if the source error had been checked. The original error |
| 190 | /// becomes a checked Success value, regardless of its original state. |
| 191 | Error(Error &&Other) { |
| 192 | setChecked(true); |
| 193 | *this = std::move(Other); |
| 194 | } |
| 195 | |
| 196 | /// Create an error value. Prefer using the 'make_error' function, but |
| 197 | /// this constructor can be useful when "re-throwing" errors from handlers. |
| 198 | Error(std::unique_ptr<ErrorInfoBase> Payload) { |
| 199 | setPtr(Payload.release()); |
| 200 | setChecked(false); |
| 201 | } |
| 202 | |
| 203 | // Errors are not copy-assignable. |
| 204 | Error &operator=(const Error &Other) = delete; |
| 205 | |
| 206 | /// Move-assign an error value. The current error must represent success, you |
| 207 | /// you cannot overwrite an unhandled error. The current error is then |
| 208 | /// considered unchecked. The source error becomes a checked success value, |
| 209 | /// regardless of its original state. |
| 210 | Error &operator=(Error &&Other) { |
| 211 | // Don't allow overwriting of unchecked values. |
| 212 | assertIsChecked(); |
| 213 | setPtr(Other.getPtr()); |
| 214 | |
| 215 | // This Error is unchecked, even if the source error was checked. |
| 216 | setChecked(false); |
| 217 | |
| 218 | // Null out Other's payload and set its checked bit. |
| 219 | Other.setPtr(nullptr); |
| 220 | Other.setChecked(true); |
| 221 | |
| 222 | return *this; |
| 223 | } |
| 224 | |
| 225 | /// Destroy a Error. Fails with a call to abort() if the error is |
| 226 | /// unchecked. |
| 227 | ~Error() { |
| 228 | assertIsChecked(); |
| 229 | delete getPtr(); |
| 230 | } |
| 231 | |
| 232 | /// Bool conversion. Returns true if this Error is in a failure state, |
| 233 | /// and false if it is in an accept state. If the error is in a Success state |
| 234 | /// it will be considered checked. |
| 235 | explicit operator bool() { |
| 236 | setChecked(getPtr() == nullptr); |
| 237 | return getPtr() != nullptr; |
| 238 | } |
| 239 | |
| 240 | /// Check whether one error is a subclass of another. |
| 241 | template <typename ErrT> bool isA() const { |
| 242 | return getPtr() && getPtr()->isA(ErrT::classID()); |
| 243 | } |
| 244 | |
| 245 | /// Returns the dynamic class id of this error, or null if this is a success |
| 246 | /// value. |
| 247 | const void* dynamicClassID() const { |
| 248 | if (!getPtr()) |
| 249 | return nullptr; |
| 250 | return getPtr()->dynamicClassID(); |
| 251 | } |
| 252 | |
| 253 | private: |
| 254 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 255 | // assertIsChecked() happens very frequently, but under normal circumstances |
| 256 | // is supposed to be a no-op. So we want it to be inlined, but having a bunch |
| 257 | // of debug prints can cause the function to be too large for inlining. So |
| 258 | // it's important that we define this function out of line so that it can't be |
| 259 | // inlined. |
| 260 | [[noreturn]] void fatalUncheckedError() const; |
| 261 | #endif |
| 262 | |
| 263 | void assertIsChecked() { |
| 264 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 265 | if (LLVM_UNLIKELY(!getChecked() || getPtr())__builtin_expect((bool)(!getChecked() || getPtr()), false)) |
| 266 | fatalUncheckedError(); |
| 267 | #endif |
| 268 | } |
| 269 | |
| 270 | ErrorInfoBase *getPtr() const { |
| 271 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 272 | return reinterpret_cast<ErrorInfoBase*>( |
| 273 | reinterpret_cast<uintptr_t>(Payload) & |
| 274 | ~static_cast<uintptr_t>(0x1)); |
| 275 | #else |
| 276 | return Payload; |
| 277 | #endif |
| 278 | } |
| 279 | |
| 280 | void setPtr(ErrorInfoBase *EI) { |
| 281 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 282 | Payload = reinterpret_cast<ErrorInfoBase*>( |
| 283 | (reinterpret_cast<uintptr_t>(EI) & |
| 284 | ~static_cast<uintptr_t>(0x1)) | |
| 285 | (reinterpret_cast<uintptr_t>(Payload) & 0x1)); |
| 286 | #else |
| 287 | Payload = EI; |
| 288 | #endif |
| 289 | } |
| 290 | |
| 291 | bool getChecked() const { |
| 292 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 293 | return (reinterpret_cast<uintptr_t>(Payload) & 0x1) == 0; |
| 294 | #else |
| 295 | return true; |
| 296 | #endif |
| 297 | } |
| 298 | |
| 299 | void setChecked(bool V) { |
| 300 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 301 | Payload = reinterpret_cast<ErrorInfoBase*>( |
| 302 | (reinterpret_cast<uintptr_t>(Payload) & |
| 303 | ~static_cast<uintptr_t>(0x1)) | |
| 304 | (V ? 0 : 1)); |
| 305 | #endif |
| 306 | } |
| 307 | |
| 308 | std::unique_ptr<ErrorInfoBase> takePayload() { |
| 309 | std::unique_ptr<ErrorInfoBase> Tmp(getPtr()); |
| 310 | setPtr(nullptr); |
| 311 | setChecked(true); |
| 312 | return Tmp; |
| 313 | } |
| 314 | |
| 315 | friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) { |
| 316 | if (auto *P = E.getPtr()) |
| 317 | P->log(OS); |
| 318 | else |
| 319 | OS << "success"; |
| 320 | return OS; |
| 321 | } |
| 322 | |
| 323 | ErrorInfoBase *Payload = nullptr; |
| 324 | }; |
| 325 | |
| 326 | /// Subclass of Error for the sole purpose of identifying the success path in |
| 327 | /// the type system. This allows to catch invalid conversion to Expected<T> at |
| 328 | /// compile time. |
| 329 | class ErrorSuccess final : public Error {}; |
| 330 | |
| 331 | inline ErrorSuccess Error::success() { return ErrorSuccess(); } |
| 332 | |
| 333 | /// Make a Error instance representing failure using the given error info |
| 334 | /// type. |
| 335 | template <typename ErrT, typename... ArgTs> Error make_error(ArgTs &&... Args) { |
| 336 | return Error(std::make_unique<ErrT>(std::forward<ArgTs>(Args)...)); |
| 337 | } |
| 338 | |
| 339 | /// Base class for user error types. Users should declare their error types |
| 340 | /// like: |
| 341 | /// |
| 342 | /// class MyError : public ErrorInfo<MyError> { |
| 343 | /// .... |
| 344 | /// }; |
| 345 | /// |
| 346 | /// This class provides an implementation of the ErrorInfoBase::kind |
| 347 | /// method, which is used by the Error RTTI system. |
| 348 | template <typename ThisErrT, typename ParentErrT = ErrorInfoBase> |
| 349 | class ErrorInfo : public ParentErrT { |
| 350 | public: |
| 351 | using ParentErrT::ParentErrT; // inherit constructors |
| 352 | |
| 353 | static const void *classID() { return &ThisErrT::ID; } |
| 354 | |
| 355 | const void *dynamicClassID() const override { return &ThisErrT::ID; } |
| 356 | |
| 357 | bool isA(const void *const ClassID) const override { |
| 358 | return ClassID == classID() || ParentErrT::isA(ClassID); |
| 359 | } |
| 360 | }; |
| 361 | |
| 362 | /// Special ErrorInfo subclass representing a list of ErrorInfos. |
| 363 | /// Instances of this class are constructed by joinError. |
| 364 | class ErrorList final : public ErrorInfo<ErrorList> { |
| 365 | // handleErrors needs to be able to iterate the payload list of an |
| 366 | // ErrorList. |
| 367 | template <typename... HandlerTs> |
| 368 | friend Error handleErrors(Error E, HandlerTs &&... Handlers); |
| 369 | |
| 370 | // joinErrors is implemented in terms of join. |
| 371 | friend Error joinErrors(Error, Error); |
| 372 | |
| 373 | public: |
| 374 | void log(raw_ostream &OS) const override { |
| 375 | OS << "Multiple errors:\n"; |
| 376 | for (const auto &ErrPayload : Payloads) { |
| 377 | ErrPayload->log(OS); |
| 378 | OS << "\n"; |
| 379 | } |
| 380 | } |
| 381 | |
| 382 | std::error_code convertToErrorCode() const override; |
| 383 | |
| 384 | // Used by ErrorInfo::classID. |
| 385 | static char ID; |
| 386 | |
| 387 | private: |
| 388 | ErrorList(std::unique_ptr<ErrorInfoBase> Payload1, |
| 389 | std::unique_ptr<ErrorInfoBase> Payload2) { |
| 390 | assert(!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() &&(static_cast <bool> (!Payload1->isA<ErrorList> () && !Payload2->isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors") ? void (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\"" , "llvm/include/llvm/Support/Error.h", 391, __extension__ __PRETTY_FUNCTION__ )) |
| 391 | "ErrorList constructor payloads should be singleton errors")(static_cast <bool> (!Payload1->isA<ErrorList> () && !Payload2->isA<ErrorList>() && "ErrorList constructor payloads should be singleton errors") ? void (0) : __assert_fail ("!Payload1->isA<ErrorList>() && !Payload2->isA<ErrorList>() && \"ErrorList constructor payloads should be singleton errors\"" , "llvm/include/llvm/Support/Error.h", 391, __extension__ __PRETTY_FUNCTION__ )); |
| 392 | Payloads.push_back(std::move(Payload1)); |
| 393 | Payloads.push_back(std::move(Payload2)); |
| 394 | } |
| 395 | |
| 396 | static Error join(Error E1, Error E2) { |
| 397 | if (!E1) |
| 398 | return E2; |
| 399 | if (!E2) |
| 400 | return E1; |
| 401 | if (E1.isA<ErrorList>()) { |
| 402 | auto &E1List = static_cast<ErrorList &>(*E1.getPtr()); |
| 403 | if (E2.isA<ErrorList>()) { |
| 404 | auto E2Payload = E2.takePayload(); |
| 405 | auto &E2List = static_cast<ErrorList &>(*E2Payload); |
| 406 | for (auto &Payload : E2List.Payloads) |
| 407 | E1List.Payloads.push_back(std::move(Payload)); |
| 408 | } else |
| 409 | E1List.Payloads.push_back(E2.takePayload()); |
| 410 | |
| 411 | return E1; |
| 412 | } |
| 413 | if (E2.isA<ErrorList>()) { |
| 414 | auto &E2List = static_cast<ErrorList &>(*E2.getPtr()); |
| 415 | E2List.Payloads.insert(E2List.Payloads.begin(), E1.takePayload()); |
| 416 | return E2; |
| 417 | } |
| 418 | return Error(std::unique_ptr<ErrorList>( |
| 419 | new ErrorList(E1.takePayload(), E2.takePayload()))); |
| 420 | } |
| 421 | |
| 422 | std::vector<std::unique_ptr<ErrorInfoBase>> Payloads; |
| 423 | }; |
| 424 | |
| 425 | /// Concatenate errors. The resulting Error is unchecked, and contains the |
| 426 | /// ErrorInfo(s), if any, contained in E1, followed by the |
| 427 | /// ErrorInfo(s), if any, contained in E2. |
| 428 | inline Error joinErrors(Error E1, Error E2) { |
| 429 | return ErrorList::join(std::move(E1), std::move(E2)); |
| 430 | } |
| 431 | |
| 432 | /// Tagged union holding either a T or a Error. |
| 433 | /// |
| 434 | /// This class parallels ErrorOr, but replaces error_code with Error. Since |
| 435 | /// Error cannot be copied, this class replaces getError() with |
| 436 | /// takeError(). It also adds an bool errorIsA<ErrT>() method for testing the |
| 437 | /// error class type. |
| 438 | /// |
| 439 | /// Example usage of 'Expected<T>' as a function return type: |
| 440 | /// |
| 441 | /// @code{.cpp} |
| 442 | /// Expected<int> myDivide(int A, int B) { |
| 443 | /// if (B == 0) { |
| 444 | /// // return an Error |
| 445 | /// return createStringError(inconvertibleErrorCode(), |
| 446 | /// "B must not be zero!"); |
| 447 | /// } |
| 448 | /// // return an integer |
| 449 | /// return A / B; |
| 450 | /// } |
| 451 | /// @endcode |
| 452 | /// |
| 453 | /// Checking the results of to a function returning 'Expected<T>': |
| 454 | /// @code{.cpp} |
| 455 | /// if (auto E = Result.takeError()) { |
| 456 | /// // We must consume the error. Typically one of: |
| 457 | /// // - return the error to our caller |
| 458 | /// // - toString(), when logging |
| 459 | /// // - consumeError(), to silently swallow the error |
| 460 | /// // - handleErrors(), to distinguish error types |
| 461 | /// errs() << "Problem with division " << toString(std::move(E)) << "\n"; |
| 462 | /// return; |
| 463 | /// } |
| 464 | /// // use the result |
| 465 | /// outs() << "The answer is " << *Result << "\n"; |
| 466 | /// @endcode |
| 467 | /// |
| 468 | /// For unit-testing a function returning an 'Expceted<T>', see the |
| 469 | /// 'EXPECT_THAT_EXPECTED' macros in llvm/Testing/Support/Error.h |
| 470 | |
| 471 | template <class T> class LLVM_NODISCARD[[clang::warn_unused_result]] Expected { |
| 472 | template <class T1> friend class ExpectedAsOutParameter; |
| 473 | template <class OtherT> friend class Expected; |
| 474 | |
| 475 | static constexpr bool isRef = std::is_reference<T>::value; |
| 476 | |
| 477 | using wrap = std::reference_wrapper<std::remove_reference_t<T>>; |
| 478 | |
| 479 | using error_type = std::unique_ptr<ErrorInfoBase>; |
| 480 | |
| 481 | public: |
| 482 | using storage_type = std::conditional_t<isRef, wrap, T>; |
| 483 | using value_type = T; |
| 484 | |
| 485 | private: |
| 486 | using reference = std::remove_reference_t<T> &; |
| 487 | using const_reference = const std::remove_reference_t<T> &; |
| 488 | using pointer = std::remove_reference_t<T> *; |
| 489 | using const_pointer = const std::remove_reference_t<T> *; |
| 490 | |
| 491 | public: |
| 492 | /// Create an Expected<T> error value from the given Error. |
| 493 | Expected(Error Err) |
| 494 | : HasError(true) |
| 495 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 496 | // Expected is unchecked upon construction in Debug builds. |
| 497 | , Unchecked(true) |
| 498 | #endif |
| 499 | { |
| 500 | assert(Err && "Cannot create Expected<T> from Error success value.")(static_cast <bool> (Err && "Cannot create Expected<T> from Error success value." ) ? void (0) : __assert_fail ("Err && \"Cannot create Expected<T> from Error success value.\"" , "llvm/include/llvm/Support/Error.h", 500, __extension__ __PRETTY_FUNCTION__ )); |
| 501 | new (getErrorStorage()) error_type(Err.takePayload()); |
| 502 | } |
| 503 | |
| 504 | /// Forbid to convert from Error::success() implicitly, this avoids having |
| 505 | /// Expected<T> foo() { return Error::success(); } which compiles otherwise |
| 506 | /// but triggers the assertion above. |
| 507 | Expected(ErrorSuccess) = delete; |
| 508 | |
| 509 | /// Create an Expected<T> success value from the given OtherT value, which |
| 510 | /// must be convertible to T. |
| 511 | template <typename OtherT> |
| 512 | Expected(OtherT &&Val, |
| 513 | std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) |
| 514 | : HasError(false) |
| 515 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 516 | // Expected is unchecked upon construction in Debug builds. |
| 517 | , |
| 518 | Unchecked(true) |
| 519 | #endif |
| 520 | { |
| 521 | new (getStorage()) storage_type(std::forward<OtherT>(Val)); |
| 522 | } |
| 523 | |
| 524 | /// Move construct an Expected<T> value. |
| 525 | Expected(Expected &&Other) { moveConstruct(std::move(Other)); } |
| 526 | |
| 527 | /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT |
| 528 | /// must be convertible to T. |
| 529 | template <class OtherT> |
| 530 | Expected( |
| 531 | Expected<OtherT> &&Other, |
| 532 | std::enable_if_t<std::is_convertible<OtherT, T>::value> * = nullptr) { |
| 533 | moveConstruct(std::move(Other)); |
| 534 | } |
| 535 | |
| 536 | /// Move construct an Expected<T> value from an Expected<OtherT>, where OtherT |
| 537 | /// isn't convertible to T. |
| 538 | template <class OtherT> |
| 539 | explicit Expected( |
| 540 | Expected<OtherT> &&Other, |
| 541 | std::enable_if_t<!std::is_convertible<OtherT, T>::value> * = nullptr) { |
| 542 | moveConstruct(std::move(Other)); |
| 543 | } |
| 544 | |
| 545 | /// Move-assign from another Expected<T>. |
| 546 | Expected &operator=(Expected &&Other) { |
| 547 | moveAssign(std::move(Other)); |
| 548 | return *this; |
| 549 | } |
| 550 | |
| 551 | /// Destroy an Expected<T>. |
| 552 | ~Expected() { |
| 553 | assertIsChecked(); |
| 554 | if (!HasError) |
| 555 | getStorage()->~storage_type(); |
| 556 | else |
| 557 | getErrorStorage()->~error_type(); |
| 558 | } |
| 559 | |
| 560 | /// Return false if there is an error. |
| 561 | explicit operator bool() { |
| 562 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 563 | Unchecked = HasError; |
| 564 | #endif |
| 565 | return !HasError; |
| 566 | } |
| 567 | |
| 568 | /// Returns a reference to the stored T value. |
| 569 | reference get() { |
| 570 | assertIsChecked(); |
| 571 | return *getStorage(); |
| 572 | } |
| 573 | |
| 574 | /// Returns a const reference to the stored T value. |
| 575 | const_reference get() const { |
| 576 | assertIsChecked(); |
| 577 | return const_cast<Expected<T> *>(this)->get(); |
| 578 | } |
| 579 | |
| 580 | /// Returns \a takeError() after moving the held T (if any) into \p V. |
| 581 | template <class OtherT> |
| 582 | Error moveInto(OtherT &Value, |
| 583 | std::enable_if_t<std::is_assignable<OtherT &, T &&>::value> * = |
| 584 | nullptr) && { |
| 585 | if (*this) |
| 586 | Value = std::move(get()); |
| 587 | return takeError(); |
| 588 | } |
| 589 | |
| 590 | /// Check that this Expected<T> is an error of type ErrT. |
| 591 | template <typename ErrT> bool errorIsA() const { |
| 592 | return HasError && (*getErrorStorage())->template isA<ErrT>(); |
| 593 | } |
| 594 | |
| 595 | /// Take ownership of the stored error. |
| 596 | /// After calling this the Expected<T> is in an indeterminate state that can |
| 597 | /// only be safely destructed. No further calls (beside the destructor) should |
| 598 | /// be made on the Expected<T> value. |
| 599 | Error takeError() { |
| 600 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 601 | Unchecked = false; |
| 602 | #endif |
| 603 | return HasError ? Error(std::move(*getErrorStorage())) : Error::success(); |
| 604 | } |
| 605 | |
| 606 | /// Returns a pointer to the stored T value. |
| 607 | pointer operator->() { |
| 608 | assertIsChecked(); |
| 609 | return toPointer(getStorage()); |
| 610 | } |
| 611 | |
| 612 | /// Returns a const pointer to the stored T value. |
| 613 | const_pointer operator->() const { |
| 614 | assertIsChecked(); |
| 615 | return toPointer(getStorage()); |
| 616 | } |
| 617 | |
| 618 | /// Returns a reference to the stored T value. |
| 619 | reference operator*() { |
| 620 | assertIsChecked(); |
| 621 | return *getStorage(); |
| 622 | } |
| 623 | |
| 624 | /// Returns a const reference to the stored T value. |
| 625 | const_reference operator*() const { |
| 626 | assertIsChecked(); |
| 627 | return *getStorage(); |
| 628 | } |
| 629 | |
| 630 | private: |
| 631 | template <class T1> |
| 632 | static bool compareThisIfSameType(const T1 &a, const T1 &b) { |
| 633 | return &a == &b; |
| 634 | } |
| 635 | |
| 636 | template <class T1, class T2> |
| 637 | static bool compareThisIfSameType(const T1 &, const T2 &) { |
| 638 | return false; |
| 639 | } |
| 640 | |
| 641 | template <class OtherT> void moveConstruct(Expected<OtherT> &&Other) { |
| 642 | HasError = Other.HasError; |
| 643 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 644 | Unchecked = true; |
| 645 | Other.Unchecked = false; |
| 646 | #endif |
| 647 | |
| 648 | if (!HasError) |
| 649 | new (getStorage()) storage_type(std::move(*Other.getStorage())); |
| 650 | else |
| 651 | new (getErrorStorage()) error_type(std::move(*Other.getErrorStorage())); |
| 652 | } |
| 653 | |
| 654 | template <class OtherT> void moveAssign(Expected<OtherT> &&Other) { |
| 655 | assertIsChecked(); |
| 656 | |
| 657 | if (compareThisIfSameType(*this, Other)) |
| 658 | return; |
| 659 | |
| 660 | this->~Expected(); |
| 661 | new (this) Expected(std::move(Other)); |
| 662 | } |
| 663 | |
| 664 | pointer toPointer(pointer Val) { return Val; } |
| 665 | |
| 666 | const_pointer toPointer(const_pointer Val) const { return Val; } |
| 667 | |
| 668 | pointer toPointer(wrap *Val) { return &Val->get(); } |
| 669 | |
| 670 | const_pointer toPointer(const wrap *Val) const { return &Val->get(); } |
| 671 | |
| 672 | storage_type *getStorage() { |
| 673 | assert(!HasError && "Cannot get value when an error exists!")(static_cast <bool> (!HasError && "Cannot get value when an error exists!" ) ? void (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\"" , "llvm/include/llvm/Support/Error.h", 673, __extension__ __PRETTY_FUNCTION__ )); |
| 674 | return reinterpret_cast<storage_type *>(&TStorage); |
| 675 | } |
| 676 | |
| 677 | const storage_type *getStorage() const { |
| 678 | assert(!HasError && "Cannot get value when an error exists!")(static_cast <bool> (!HasError && "Cannot get value when an error exists!" ) ? void (0) : __assert_fail ("!HasError && \"Cannot get value when an error exists!\"" , "llvm/include/llvm/Support/Error.h", 678, __extension__ __PRETTY_FUNCTION__ )); |
| 679 | return reinterpret_cast<const storage_type *>(&TStorage); |
| 680 | } |
| 681 | |
| 682 | error_type *getErrorStorage() { |
| 683 | assert(HasError && "Cannot get error when a value exists!")(static_cast <bool> (HasError && "Cannot get error when a value exists!" ) ? void (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\"" , "llvm/include/llvm/Support/Error.h", 683, __extension__ __PRETTY_FUNCTION__ )); |
| 684 | return reinterpret_cast<error_type *>(&ErrorStorage); |
| 685 | } |
| 686 | |
| 687 | const error_type *getErrorStorage() const { |
| 688 | assert(HasError && "Cannot get error when a value exists!")(static_cast <bool> (HasError && "Cannot get error when a value exists!" ) ? void (0) : __assert_fail ("HasError && \"Cannot get error when a value exists!\"" , "llvm/include/llvm/Support/Error.h", 688, __extension__ __PRETTY_FUNCTION__ )); |
| 689 | return reinterpret_cast<const error_type *>(&ErrorStorage); |
| 690 | } |
| 691 | |
| 692 | // Used by ExpectedAsOutParameter to reset the checked flag. |
| 693 | void setUnchecked() { |
| 694 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 695 | Unchecked = true; |
| 696 | #endif |
| 697 | } |
| 698 | |
| 699 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 700 | [[noreturn]] LLVM_ATTRIBUTE_NOINLINE__attribute__((noinline)) void fatalUncheckedExpected() const { |
| 701 | dbgs() << "Expected<T> must be checked before access or destruction.\n"; |
| 702 | if (HasError) { |
| 703 | dbgs() << "Unchecked Expected<T> contained error:\n"; |
| 704 | (*getErrorStorage())->log(dbgs()); |
| 705 | } else |
| 706 | dbgs() << "Expected<T> value was in success state. (Note: Expected<T> " |
| 707 | "values in success mode must still be checked prior to being " |
| 708 | "destroyed).\n"; |
| 709 | abort(); |
| 710 | } |
| 711 | #endif |
| 712 | |
| 713 | void assertIsChecked() const { |
| 714 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 715 | if (LLVM_UNLIKELY(Unchecked)__builtin_expect((bool)(Unchecked), false)) |
| 716 | fatalUncheckedExpected(); |
| 717 | #endif |
| 718 | } |
| 719 | |
| 720 | union { |
| 721 | AlignedCharArrayUnion<storage_type> TStorage; |
| 722 | AlignedCharArrayUnion<error_type> ErrorStorage; |
| 723 | }; |
| 724 | bool HasError : 1; |
| 725 | #if LLVM_ENABLE_ABI_BREAKING_CHECKS1 |
| 726 | bool Unchecked : 1; |
| 727 | #endif |
| 728 | }; |
| 729 | |
| 730 | /// Report a serious error, calling any installed error handler. See |
| 731 | /// ErrorHandling.h. |
| 732 | [[noreturn]] void report_fatal_error(Error Err, bool gen_crash_diag = true); |
| 733 | |
| 734 | /// Report a fatal error if Err is a failure value. |
| 735 | /// |
| 736 | /// This function can be used to wrap calls to fallible functions ONLY when it |
| 737 | /// is known that the Error will always be a success value. E.g. |
| 738 | /// |
| 739 | /// @code{.cpp} |
| 740 | /// // foo only attempts the fallible operation if DoFallibleOperation is |
| 741 | /// // true. If DoFallibleOperation is false then foo always returns |
| 742 | /// // Error::success(). |
| 743 | /// Error foo(bool DoFallibleOperation); |
| 744 | /// |
| 745 | /// cantFail(foo(false)); |
| 746 | /// @endcode |
| 747 | inline void cantFail(Error Err, const char *Msg = nullptr) { |
| 748 | if (Err) { |
| 749 | if (!Msg) |
| 750 | Msg = "Failure value returned from cantFail wrapped call"; |
| 751 | #ifndef NDEBUG |
| 752 | std::string Str; |
| 753 | raw_string_ostream OS(Str); |
| 754 | OS << Msg << "\n" << Err; |
| 755 | Msg = OS.str().c_str(); |
| 756 | #endif |
| 757 | llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "llvm/include/llvm/Support/Error.h" , 757); |
| 758 | } |
| 759 | } |
| 760 | |
| 761 | /// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and |
| 762 | /// returns the contained value. |
| 763 | /// |
| 764 | /// This function can be used to wrap calls to fallible functions ONLY when it |
| 765 | /// is known that the Error will always be a success value. E.g. |
| 766 | /// |
| 767 | /// @code{.cpp} |
| 768 | /// // foo only attempts the fallible operation if DoFallibleOperation is |
| 769 | /// // true. If DoFallibleOperation is false then foo always returns an int. |
| 770 | /// Expected<int> foo(bool DoFallibleOperation); |
| 771 | /// |
| 772 | /// int X = cantFail(foo(false)); |
| 773 | /// @endcode |
| 774 | template <typename T> |
| 775 | T cantFail(Expected<T> ValOrErr, const char *Msg = nullptr) { |
| 776 | if (ValOrErr) |
| 777 | return std::move(*ValOrErr); |
| 778 | else { |
| 779 | if (!Msg) |
| 780 | Msg = "Failure value returned from cantFail wrapped call"; |
| 781 | #ifndef NDEBUG |
| 782 | std::string Str; |
| 783 | raw_string_ostream OS(Str); |
| 784 | auto E = ValOrErr.takeError(); |
| 785 | OS << Msg << "\n" << E; |
| 786 | Msg = OS.str().c_str(); |
| 787 | #endif |
| 788 | llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "llvm/include/llvm/Support/Error.h" , 788); |
| 789 | } |
| 790 | } |
| 791 | |
| 792 | /// Report a fatal error if ValOrErr is a failure value, otherwise unwraps and |
| 793 | /// returns the contained reference. |
| 794 | /// |
| 795 | /// This function can be used to wrap calls to fallible functions ONLY when it |
| 796 | /// is known that the Error will always be a success value. E.g. |
| 797 | /// |
| 798 | /// @code{.cpp} |
| 799 | /// // foo only attempts the fallible operation if DoFallibleOperation is |
| 800 | /// // true. If DoFallibleOperation is false then foo always returns a Bar&. |
| 801 | /// Expected<Bar&> foo(bool DoFallibleOperation); |
| 802 | /// |
| 803 | /// Bar &X = cantFail(foo(false)); |
| 804 | /// @endcode |
| 805 | template <typename T> |
| 806 | T& cantFail(Expected<T&> ValOrErr, const char *Msg = nullptr) { |
| 807 | if (ValOrErr) |
| 808 | return *ValOrErr; |
| 809 | else { |
| 810 | if (!Msg) |
| 811 | Msg = "Failure value returned from cantFail wrapped call"; |
| 812 | #ifndef NDEBUG |
| 813 | std::string Str; |
| 814 | raw_string_ostream OS(Str); |
| 815 | auto E = ValOrErr.takeError(); |
| 816 | OS << Msg << "\n" << E; |
| 817 | Msg = OS.str().c_str(); |
| 818 | #endif |
| 819 | llvm_unreachable(Msg)::llvm::llvm_unreachable_internal(Msg, "llvm/include/llvm/Support/Error.h" , 819); |
| 820 | } |
| 821 | } |
| 822 | |
| 823 | /// Helper for testing applicability of, and applying, handlers for |
| 824 | /// ErrorInfo types. |
| 825 | template <typename HandlerT> |
| 826 | class ErrorHandlerTraits |
| 827 | : public ErrorHandlerTraits<decltype( |
| 828 | &std::remove_reference<HandlerT>::type::operator())> {}; |
| 829 | |
| 830 | // Specialization functions of the form 'Error (const ErrT&)'. |
| 831 | template <typename ErrT> class ErrorHandlerTraits<Error (&)(ErrT &)> { |
| 832 | public: |
| 833 | static bool appliesTo(const ErrorInfoBase &E) { |
| 834 | return E.template isA<ErrT>(); |
| 835 | } |
| 836 | |
| 837 | template <typename HandlerT> |
| 838 | static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) { |
| 839 | assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler" ) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\"" , "llvm/include/llvm/Support/Error.h", 839, __extension__ __PRETTY_FUNCTION__ )); |
| 840 | return H(static_cast<ErrT &>(*E)); |
| 841 | } |
| 842 | }; |
| 843 | |
| 844 | // Specialization functions of the form 'void (const ErrT&)'. |
| 845 | template <typename ErrT> class ErrorHandlerTraits<void (&)(ErrT &)> { |
| 846 | public: |
| 847 | static bool appliesTo(const ErrorInfoBase &E) { |
| 848 | return E.template isA<ErrT>(); |
| 849 | } |
| 850 | |
| 851 | template <typename HandlerT> |
| 852 | static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) { |
| 853 | assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler" ) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\"" , "llvm/include/llvm/Support/Error.h", 853, __extension__ __PRETTY_FUNCTION__ )); |
| 854 | H(static_cast<ErrT &>(*E)); |
| 855 | return Error::success(); |
| 856 | } |
| 857 | }; |
| 858 | |
| 859 | /// Specialization for functions of the form 'Error (std::unique_ptr<ErrT>)'. |
| 860 | template <typename ErrT> |
| 861 | class ErrorHandlerTraits<Error (&)(std::unique_ptr<ErrT>)> { |
| 862 | public: |
| 863 | static bool appliesTo(const ErrorInfoBase &E) { |
| 864 | return E.template isA<ErrT>(); |
| 865 | } |
| 866 | |
| 867 | template <typename HandlerT> |
| 868 | static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) { |
| 869 | assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler" ) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\"" , "llvm/include/llvm/Support/Error.h", 869, __extension__ __PRETTY_FUNCTION__ )); |
| 870 | std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release())); |
| 871 | return H(std::move(SubE)); |
| 872 | } |
| 873 | }; |
| 874 | |
| 875 | /// Specialization for functions of the form 'void (std::unique_ptr<ErrT>)'. |
| 876 | template <typename ErrT> |
| 877 | class ErrorHandlerTraits<void (&)(std::unique_ptr<ErrT>)> { |
| 878 | public: |
| 879 | static bool appliesTo(const ErrorInfoBase &E) { |
| 880 | return E.template isA<ErrT>(); |
| 881 | } |
| 882 | |
| 883 | template <typename HandlerT> |
| 884 | static Error apply(HandlerT &&H, std::unique_ptr<ErrorInfoBase> E) { |
| 885 | assert(appliesTo(*E) && "Applying incorrect handler")(static_cast <bool> (appliesTo(*E) && "Applying incorrect handler" ) ? void (0) : __assert_fail ("appliesTo(*E) && \"Applying incorrect handler\"" , "llvm/include/llvm/Support/Error.h", 885, __extension__ __PRETTY_FUNCTION__ )); |
| 886 | std::unique_ptr<ErrT> SubE(static_cast<ErrT *>(E.release())); |
| 887 | H(std::move(SubE)); |
| 888 | return Error::success(); |
| 889 | } |
| 890 | }; |
| 891 | |
| 892 | // Specialization for member functions of the form 'RetT (const ErrT&)'. |
| 893 | template <typename C, typename RetT, typename ErrT> |
| 894 | class ErrorHandlerTraits<RetT (C::*)(ErrT &)> |
| 895 | : public ErrorHandlerTraits<RetT (&)(ErrT &)> {}; |
| 896 | |
| 897 | // Specialization for member functions of the form 'RetT (const ErrT&) const'. |
| 898 | template <typename C, typename RetT, typename ErrT> |
| 899 | class ErrorHandlerTraits<RetT (C::*)(ErrT &) const> |
| 900 | : public ErrorHandlerTraits<RetT (&)(ErrT &)> {}; |
| 901 | |
| 902 | // Specialization for member functions of the form 'RetT (const ErrT&)'. |
| 903 | template <typename C, typename RetT, typename ErrT> |
| 904 | class ErrorHandlerTraits<RetT (C::*)(const ErrT &)> |
| 905 | : public ErrorHandlerTraits<RetT (&)(ErrT &)> {}; |
| 906 | |
| 907 | // Specialization for member functions of the form 'RetT (const ErrT&) const'. |
| 908 | template <typename C, typename RetT, typename ErrT> |
| 909 | class ErrorHandlerTraits<RetT (C::*)(const ErrT &) const> |
| 910 | : public ErrorHandlerTraits<RetT (&)(ErrT &)> {}; |
| 911 | |
| 912 | /// Specialization for member functions of the form |
| 913 | /// 'RetT (std::unique_ptr<ErrT>)'. |
| 914 | template <typename C, typename RetT, typename ErrT> |
| 915 | class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>)> |
| 916 | : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {}; |
| 917 | |
| 918 | /// Specialization for member functions of the form |
| 919 | /// 'RetT (std::unique_ptr<ErrT>) const'. |
| 920 | template <typename C, typename RetT, typename ErrT> |
| 921 | class ErrorHandlerTraits<RetT (C::*)(std::unique_ptr<ErrT>) const> |
| 922 | : public ErrorHandlerTraits<RetT (&)(std::unique_ptr<ErrT>)> {}; |
| 923 | |
| 924 | inline Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload) { |
| 925 | return Error(std::move(Payload)); |
| 926 | } |
| 927 | |
| 928 | template <typename HandlerT, typename... HandlerTs> |
| 929 | Error handleErrorImpl(std::unique_ptr<ErrorInfoBase> Payload, |
| 930 | HandlerT &&Handler, HandlerTs &&... Handlers) { |
| 931 | if (ErrorHandlerTraits<HandlerT>::appliesTo(*Payload)) |
| 932 | return ErrorHandlerTraits<HandlerT>::apply(std::forward<HandlerT>(Handler), |
| 933 | std::move(Payload)); |
| 934 | return handleErrorImpl(std::move(Payload), |
| 935 | std::forward<HandlerTs>(Handlers)...); |
| 936 | } |
| 937 | |
| 938 | /// Pass the ErrorInfo(s) contained in E to their respective handlers. Any |
| 939 | /// unhandled errors (or Errors returned by handlers) are re-concatenated and |
| 940 | /// returned. |
| 941 | /// Because this function returns an error, its result must also be checked |
| 942 | /// or returned. If you intend to handle all errors use handleAllErrors |
| 943 | /// (which returns void, and will abort() on unhandled errors) instead. |
| 944 | template <typename... HandlerTs> |
| 945 | Error handleErrors(Error E, HandlerTs &&... Hs) { |
| 946 | if (!E) |
| 947 | return Error::success(); |
| 948 | |
| 949 | std::unique_ptr<ErrorInfoBase> Payload = E.takePayload(); |
| 950 | |
| 951 | if (Payload->isA<ErrorList>()) { |
| 952 | ErrorList &List = static_cast<ErrorList &>(*Payload); |
| 953 | Error R; |
| 954 | for (auto &P : List.Payloads) |
| 955 | R = ErrorList::join( |
| 956 | std::move(R), |
| 957 | handleErrorImpl(std::move(P), std::forward<HandlerTs>(Hs)...)); |
| 958 | return R; |
| 959 | } |
| 960 | |
| 961 | return handleErrorImpl(std::move(Payload), std::forward<HandlerTs>(Hs)...); |
| 962 | } |
| 963 | |
| 964 | /// Behaves the same as handleErrors, except that by contract all errors |
| 965 | /// *must* be handled by the given handlers (i.e. there must be no remaining |
| 966 | /// errors after running the handlers, or llvm_unreachable is called). |
| 967 | template <typename... HandlerTs> |
| 968 | void handleAllErrors(Error E, HandlerTs &&... Handlers) { |
| 969 | cantFail(handleErrors(std::move(E), std::forward<HandlerTs>(Handlers)...)); |
| 970 | } |
| 971 | |
| 972 | /// Check that E is a non-error, then drop it. |
| 973 | /// If E is an error, llvm_unreachable will be called. |
| 974 | inline void handleAllErrors(Error E) { |
| 975 | cantFail(std::move(E)); |
| 976 | } |
| 977 | |
| 978 | /// Handle any errors (if present) in an Expected<T>, then try a recovery path. |
| 979 | /// |
| 980 | /// If the incoming value is a success value it is returned unmodified. If it |
| 981 | /// is a failure value then it the contained error is passed to handleErrors. |
| 982 | /// If handleErrors is able to handle the error then the RecoveryPath functor |
| 983 | /// is called to supply the final result. If handleErrors is not able to |
| 984 | /// handle all errors then the unhandled errors are returned. |
| 985 | /// |
| 986 | /// This utility enables the follow pattern: |
| 987 | /// |
| 988 | /// @code{.cpp} |
| 989 | /// enum FooStrategy { Aggressive, Conservative }; |
| 990 | /// Expected<Foo> foo(FooStrategy S); |
| 991 | /// |
| 992 | /// auto ResultOrErr = |
| 993 | /// handleExpected( |
| 994 | /// foo(Aggressive), |
| 995 | /// []() { return foo(Conservative); }, |
| 996 | /// [](AggressiveStrategyError&) { |
| 997 | /// // Implicitly conusme this - we'll recover by using a conservative |
| 998 | /// // strategy. |
| 999 | /// }); |
| 1000 | /// |
| 1001 | /// @endcode |
| 1002 | template <typename T, typename RecoveryFtor, typename... HandlerTs> |
| 1003 | Expected<T> handleExpected(Expected<T> ValOrErr, RecoveryFtor &&RecoveryPath, |
| 1004 | HandlerTs &&... Handlers) { |
| 1005 | if (ValOrErr) |
| 1006 | return ValOrErr; |
| 1007 | |
| 1008 | if (auto Err = handleErrors(ValOrErr.takeError(), |
| 1009 | std::forward<HandlerTs>(Handlers)...)) |
| 1010 | return std::move(Err); |
| 1011 | |
| 1012 | return RecoveryPath(); |
| 1013 | } |
| 1014 | |
| 1015 | /// Log all errors (if any) in E to OS. If there are any errors, ErrorBanner |
| 1016 | /// will be printed before the first one is logged. A newline will be printed |
| 1017 | /// after each error. |
| 1018 | /// |
| 1019 | /// This function is compatible with the helpers from Support/WithColor.h. You |
| 1020 | /// can pass any of them as the OS. Please consider using them instead of |
| 1021 | /// including 'error: ' in the ErrorBanner. |
| 1022 | /// |
| 1023 | /// This is useful in the base level of your program to allow clean termination |
| 1024 | /// (allowing clean deallocation of resources, etc.), while reporting error |
| 1025 | /// information to the user. |
| 1026 | void logAllUnhandledErrors(Error E, raw_ostream &OS, Twine ErrorBanner = {}); |
| 1027 | |
| 1028 | /// Write all error messages (if any) in E to a string. The newline character |
| 1029 | /// is used to separate error messages. |
| 1030 | inline std::string toString(Error E) { |
| 1031 | SmallVector<std::string, 2> Errors; |
| 1032 | handleAllErrors(std::move(E), [&Errors](const ErrorInfoBase &EI) { |
| 1033 | Errors.push_back(EI.message()); |
| 1034 | }); |
| 1035 | return join(Errors.begin(), Errors.end(), "\n"); |
| 1036 | } |
| 1037 | |
| 1038 | /// Consume a Error without doing anything. This method should be used |
| 1039 | /// only where an error can be considered a reasonable and expected return |
| 1040 | /// value. |
| 1041 | /// |
| 1042 | /// Uses of this method are potentially indicative of design problems: If it's |
| 1043 | /// legitimate to do nothing while processing an "error", the error-producer |
| 1044 | /// might be more clearly refactored to return an Optional<T>. |
| 1045 | inline void consumeError(Error Err) { |
| 1046 | handleAllErrors(std::move(Err), [](const ErrorInfoBase &) {}); |
| 1047 | } |
| 1048 | |
| 1049 | /// Convert an Expected to an Optional without doing anything. This method |
| 1050 | /// should be used only where an error can be considered a reasonable and |
| 1051 | /// expected return value. |
| 1052 | /// |
| 1053 | /// Uses of this method are potentially indicative of problems: perhaps the |
| 1054 | /// error should be propagated further, or the error-producer should just |
| 1055 | /// return an Optional in the first place. |
| 1056 | template <typename T> Optional<T> expectedToOptional(Expected<T> &&E) { |
| 1057 | if (E) |
| 1058 | return std::move(*E); |
| 1059 | consumeError(E.takeError()); |
| 1060 | return None; |
| 1061 | } |
| 1062 | |
| 1063 | /// Helper for converting an Error to a bool. |
| 1064 | /// |
| 1065 | /// This method returns true if Err is in an error state, or false if it is |
| 1066 | /// in a success state. Puts Err in a checked state in both cases (unlike |
| 1067 | /// Error::operator bool(), which only does this for success states). |
| 1068 | inline bool errorToBool(Error Err) { |
| 1069 | bool IsError = static_cast<bool>(Err); |
| 1070 | if (IsError) |
| 1071 | consumeError(std::move(Err)); |
| 1072 | return IsError; |
| 1073 | } |
| 1074 | |
| 1075 | /// Helper for Errors used as out-parameters. |
| 1076 | /// |
| 1077 | /// This helper is for use with the Error-as-out-parameter idiom, where an error |
| 1078 | /// is passed to a function or method by reference, rather than being returned. |
| 1079 | /// In such cases it is helpful to set the checked bit on entry to the function |
| 1080 | /// so that the error can be written to (unchecked Errors abort on assignment) |
| 1081 | /// and clear the checked bit on exit so that clients cannot accidentally forget |
| 1082 | /// to check the result. This helper performs these actions automatically using |
| 1083 | /// RAII: |
| 1084 | /// |
| 1085 | /// @code{.cpp} |
| 1086 | /// Result foo(Error &Err) { |
| 1087 | /// ErrorAsOutParameter ErrAsOutParam(&Err); // 'Checked' flag set |
| 1088 | /// // <body of foo> |
| 1089 | /// // <- 'Checked' flag auto-cleared when ErrAsOutParam is destructed. |
| 1090 | /// } |
| 1091 | /// @endcode |
| 1092 | /// |
| 1093 | /// ErrorAsOutParameter takes an Error* rather than Error& so that it can be |
| 1094 | /// used with optional Errors (Error pointers that are allowed to be null). If |
| 1095 | /// ErrorAsOutParameter took an Error reference, an instance would have to be |
| 1096 | /// created inside every condition that verified that Error was non-null. By |
| 1097 | /// taking an Error pointer we can just create one instance at the top of the |
| 1098 | /// function. |
| 1099 | class ErrorAsOutParameter { |
| 1100 | public: |
| 1101 | ErrorAsOutParameter(Error *Err) : Err(Err) { |
| 1102 | // Raise the checked bit if Err is success. |
| 1103 | if (Err) |
| 1104 | (void)!!*Err; |
| 1105 | } |
| 1106 | |
| 1107 | ~ErrorAsOutParameter() { |
| 1108 | // Clear the checked bit. |
| 1109 | if (Err && !*Err) |
| 1110 | *Err = Error::success(); |
| 1111 | } |
| 1112 | |
| 1113 | private: |
| 1114 | Error *Err; |
| 1115 | }; |
| 1116 | |
| 1117 | /// Helper for Expected<T>s used as out-parameters. |
| 1118 | /// |
| 1119 | /// See ErrorAsOutParameter. |
| 1120 | template <typename T> |
| 1121 | class ExpectedAsOutParameter { |
| 1122 | public: |
| 1123 | ExpectedAsOutParameter(Expected<T> *ValOrErr) |
| 1124 | : ValOrErr(ValOrErr) { |
| 1125 | if (ValOrErr) |
| 1126 | (void)!!*ValOrErr; |
| 1127 | } |
| 1128 | |
| 1129 | ~ExpectedAsOutParameter() { |
| 1130 | if (ValOrErr) |
| 1131 | ValOrErr->setUnchecked(); |
| 1132 | } |
| 1133 | |
| 1134 | private: |
| 1135 | Expected<T> *ValOrErr; |
| 1136 | }; |
| 1137 | |
| 1138 | /// This class wraps a std::error_code in a Error. |
| 1139 | /// |
| 1140 | /// This is useful if you're writing an interface that returns a Error |
| 1141 | /// (or Expected) and you want to call code that still returns |
| 1142 | /// std::error_codes. |
| 1143 | class ECError : public ErrorInfo<ECError> { |
| 1144 | friend Error errorCodeToError(std::error_code); |
| 1145 | |
| 1146 | virtual void anchor() override; |
| 1147 | |
| 1148 | public: |
| 1149 | void setErrorCode(std::error_code EC) { this->EC = EC; } |
| 1150 | std::error_code convertToErrorCode() const override { return EC; } |
| 1151 | void log(raw_ostream &OS) const override { OS << EC.message(); } |
| 1152 | |
| 1153 | // Used by ErrorInfo::classID. |
| 1154 | static char ID; |
| 1155 | |
| 1156 | protected: |
| 1157 | ECError() = default; |
| 1158 | ECError(std::error_code EC) : EC(EC) {} |
| 1159 | |
| 1160 | std::error_code EC; |
| 1161 | }; |
| 1162 | |
| 1163 | /// The value returned by this function can be returned from convertToErrorCode |
| 1164 | /// for Error values where no sensible translation to std::error_code exists. |
| 1165 | /// It should only be used in this situation, and should never be used where a |
| 1166 | /// sensible conversion to std::error_code is available, as attempts to convert |
| 1167 | /// to/from this error will result in a fatal error. (i.e. it is a programmatic |
| 1168 | /// error to try to convert such a value). |
| 1169 | std::error_code inconvertibleErrorCode(); |
| 1170 | |
| 1171 | /// Helper for converting an std::error_code to a Error. |
| 1172 | Error errorCodeToError(std::error_code EC); |
| 1173 | |
| 1174 | /// Helper for converting an ECError to a std::error_code. |
| 1175 | /// |
| 1176 | /// This method requires that Err be Error() or an ECError, otherwise it |
| 1177 | /// will trigger a call to abort(). |
| 1178 | std::error_code errorToErrorCode(Error Err); |
| 1179 | |
| 1180 | /// Convert an ErrorOr<T> to an Expected<T>. |
| 1181 | template <typename T> Expected<T> errorOrToExpected(ErrorOr<T> &&EO) { |
| 1182 | if (auto EC = EO.getError()) |
| 1183 | return errorCodeToError(EC); |
| 1184 | return std::move(*EO); |
| 1185 | } |
| 1186 | |
| 1187 | /// Convert an Expected<T> to an ErrorOr<T>. |
| 1188 | template <typename T> ErrorOr<T> expectedToErrorOr(Expected<T> &&E) { |
| 1189 | if (auto Err = E.takeError()) |
| 1190 | return errorToErrorCode(std::move(Err)); |
| 1191 | return std::move(*E); |
| 1192 | } |
| 1193 | |
| 1194 | /// This class wraps a string in an Error. |
| 1195 | /// |
| 1196 | /// StringError is useful in cases where the client is not expected to be able |
| 1197 | /// to consume the specific error message programmatically (for example, if the |
| 1198 | /// error message is to be presented to the user). |
| 1199 | /// |
| 1200 | /// StringError can also be used when additional information is to be printed |
| 1201 | /// along with a error_code message. Depending on the constructor called, this |
| 1202 | /// class can either display: |
| 1203 | /// 1. the error_code message (ECError behavior) |
| 1204 | /// 2. a string |
| 1205 | /// 3. the error_code message and a string |
| 1206 | /// |
| 1207 | /// These behaviors are useful when subtyping is required; for example, when a |
| 1208 | /// specific library needs an explicit error type. In the example below, |
| 1209 | /// PDBError is derived from StringError: |
| 1210 | /// |
| 1211 | /// @code{.cpp} |
| 1212 | /// Expected<int> foo() { |
| 1213 | /// return llvm::make_error<PDBError>(pdb_error_code::dia_failed_loading, |
| 1214 | /// "Additional information"); |
| 1215 | /// } |
| 1216 | /// @endcode |
| 1217 | /// |
| 1218 | class StringError : public ErrorInfo<StringError> { |
| 1219 | public: |
| 1220 | static char ID; |
| 1221 | |
| 1222 | // Prints EC + S and converts to EC |
| 1223 | StringError(std::error_code EC, const Twine &S = Twine()); |
| 1224 | |
| 1225 | // Prints S and converts to EC |
| 1226 | StringError(const Twine &S, std::error_code EC); |
| 1227 | |
| 1228 | void log(raw_ostream &OS) const override; |
| 1229 | std::error_code convertToErrorCode() const override; |
| 1230 | |
| 1231 | const std::string &getMessage() const { return Msg; } |
| 1232 | |
| 1233 | private: |
| 1234 | std::string Msg; |
| 1235 | std::error_code EC; |
| 1236 | const bool PrintMsgOnly = false; |
| 1237 | }; |
| 1238 | |
| 1239 | /// Create formatted StringError object. |
| 1240 | template <typename... Ts> |
| 1241 | inline Error createStringError(std::error_code EC, char const *Fmt, |
| 1242 | const Ts &... Vals) { |
| 1243 | std::string Buffer; |
| 1244 | raw_string_ostream Stream(Buffer); |
| 1245 | Stream << format(Fmt, Vals...); |
| 1246 | return make_error<StringError>(Stream.str(), EC); |
| 1247 | } |
| 1248 | |
| 1249 | Error createStringError(std::error_code EC, char const *Msg); |
| 1250 | |
| 1251 | inline Error createStringError(std::error_code EC, const Twine &S) { |
| 1252 | return createStringError(EC, S.str().c_str()); |
| 1253 | } |
| 1254 | |
| 1255 | template <typename... Ts> |
| 1256 | inline Error createStringError(std::errc EC, char const *Fmt, |
| 1257 | const Ts &... Vals) { |
| 1258 | return createStringError(std::make_error_code(EC), Fmt, Vals...); |
| 1259 | } |
| 1260 | |
| 1261 | /// This class wraps a filename and another Error. |
| 1262 | /// |
| 1263 | /// In some cases, an error needs to live along a 'source' name, in order to |
| 1264 | /// show more detailed information to the user. |
| 1265 | class FileError final : public ErrorInfo<FileError> { |
| 1266 | |
| 1267 | friend Error createFileError(const Twine &, Error); |
| 1268 | friend Error createFileError(const Twine &, size_t, Error); |
| 1269 | |
| 1270 | public: |
| 1271 | void log(raw_ostream &OS) const override { |
| 1272 | assert(Err && "Trying to log after takeError().")(static_cast <bool> (Err && "Trying to log after takeError()." ) ? void (0) : __assert_fail ("Err && \"Trying to log after takeError().\"" , "llvm/include/llvm/Support/Error.h", 1272, __extension__ __PRETTY_FUNCTION__ )); |
| 1273 | OS << "'" << FileName << "': "; |
| 1274 | if (Line.hasValue()) |
| 1275 | OS << "line " << Line.getValue() << ": "; |
| 1276 | Err->log(OS); |
| 1277 | } |
| 1278 | |
| 1279 | std::string messageWithoutFileInfo() const { |
| 1280 | std::string Msg; |
| 1281 | raw_string_ostream OS(Msg); |
| 1282 | Err->log(OS); |
| 1283 | return OS.str(); |
| 1284 | } |
| 1285 | |
| 1286 | StringRef getFileName() { return FileName; } |
| 1287 | |
| 1288 | Error takeError() { return Error(std::move(Err)); } |
| 1289 | |
| 1290 | std::error_code convertToErrorCode() const override; |
| 1291 | |
| 1292 | // Used by ErrorInfo::classID. |
| 1293 | static char ID; |
| 1294 | |
| 1295 | private: |
| 1296 | FileError(const Twine &F, Optional<size_t> LineNum, |
| 1297 | std::unique_ptr<ErrorInfoBase> E) { |
| 1298 | assert(E && "Cannot create FileError from Error success value.")(static_cast <bool> (E && "Cannot create FileError from Error success value." ) ? void (0) : __assert_fail ("E && \"Cannot create FileError from Error success value.\"" , "llvm/include/llvm/Support/Error.h", 1298, __extension__ __PRETTY_FUNCTION__ )); |
| 1299 | FileName = F.str(); |
| 1300 | Err = std::move(E); |
| 1301 | Line = std::move(LineNum); |
| 1302 | } |
| 1303 | |
| 1304 | static Error build(const Twine &F, Optional<size_t> Line, Error E) { |
| 1305 | std::unique_ptr<ErrorInfoBase> Payload; |
| 1306 | handleAllErrors(std::move(E), |
| 1307 | [&](std::unique_ptr<ErrorInfoBase> EIB) -> Error { |
| 1308 | Payload = std::move(EIB); |
| 1309 | return Error::success(); |
| 1310 | }); |
| 1311 | return Error( |
| 1312 | std::unique_ptr<FileError>(new FileError(F, Line, std::move(Payload)))); |
| 1313 | } |
| 1314 | |
| 1315 | std::string FileName; |
| 1316 | Optional<size_t> Line; |
| 1317 | std::unique_ptr<ErrorInfoBase> Err; |
| 1318 | }; |
| 1319 | |
| 1320 | /// Concatenate a source file path and/or name with an Error. The resulting |
| 1321 | /// Error is unchecked. |
| 1322 | inline Error createFileError(const Twine &F, Error E) { |
| 1323 | return FileError::build(F, Optional<size_t>(), std::move(E)); |
| 1324 | } |
| 1325 | |
| 1326 | /// Concatenate a source file path and/or name with line number and an Error. |
| 1327 | /// The resulting Error is unchecked. |
| 1328 | inline Error createFileError(const Twine &F, size_t Line, Error E) { |
| 1329 | return FileError::build(F, Optional<size_t>(Line), std::move(E)); |
| 1330 | } |
| 1331 | |
| 1332 | /// Concatenate a source file path and/or name with a std::error_code |
| 1333 | /// to form an Error object. |
| 1334 | inline Error createFileError(const Twine &F, std::error_code EC) { |
| 1335 | return createFileError(F, errorCodeToError(EC)); |
| 1336 | } |
| 1337 | |
| 1338 | /// Concatenate a source file path and/or name with line number and |
| 1339 | /// std::error_code to form an Error object. |
| 1340 | inline Error createFileError(const Twine &F, size_t Line, std::error_code EC) { |
| 1341 | return createFileError(F, Line, errorCodeToError(EC)); |
| 1342 | } |
| 1343 | |
| 1344 | Error createFileError(const Twine &F, ErrorSuccess) = delete; |
| 1345 | |
| 1346 | /// Helper for check-and-exit error handling. |
| 1347 | /// |
| 1348 | /// For tool use only. NOT FOR USE IN LIBRARY CODE. |
| 1349 | /// |
| 1350 | class ExitOnError { |
| 1351 | public: |
| 1352 | /// Create an error on exit helper. |
| 1353 | ExitOnError(std::string Banner = "", int DefaultErrorExitCode = 1) |
| 1354 | : Banner(std::move(Banner)), |
| 1355 | GetExitCode([=](const Error &) { return DefaultErrorExitCode; }) {} |
| 1356 | |
| 1357 | /// Set the banner string for any errors caught by operator(). |
| 1358 | void setBanner(std::string Banner) { this->Banner = std::move(Banner); } |
| 1359 | |
| 1360 | /// Set the exit-code mapper function. |
| 1361 | void setExitCodeMapper(std::function<int(const Error &)> GetExitCode) { |
| 1362 | this->GetExitCode = std::move(GetExitCode); |
| 1363 | } |
| 1364 | |
| 1365 | /// Check Err. If it's in a failure state log the error(s) and exit. |
| 1366 | void operator()(Error Err) const { checkError(std::move(Err)); } |
| 1367 | |
| 1368 | /// Check E. If it's in a success state then return the contained value. If |
| 1369 | /// it's in a failure state log the error(s) and exit. |
| 1370 | template <typename T> T operator()(Expected<T> &&E) const { |
| 1371 | checkError(E.takeError()); |
| 1372 | return std::move(*E); |
| 1373 | } |
| 1374 | |
| 1375 | /// Check E. If it's in a success state then return the contained reference. If |
| 1376 | /// it's in a failure state log the error(s) and exit. |
| 1377 | template <typename T> T& operator()(Expected<T&> &&E) const { |
| 1378 | checkError(E.takeError()); |
| 1379 | return *E; |
| 1380 | } |
| 1381 | |
| 1382 | private: |
| 1383 | void checkError(Error Err) const { |
| 1384 | if (Err) { |
| 1385 | int ExitCode = GetExitCode(Err); |
| 1386 | logAllUnhandledErrors(std::move(Err), errs(), Banner); |
| 1387 | exit(ExitCode); |
| 1388 | } |
| 1389 | } |
| 1390 | |
| 1391 | std::string Banner; |
| 1392 | std::function<int(const Error &)> GetExitCode; |
| 1393 | }; |
| 1394 | |
| 1395 | /// Conversion from Error to LLVMErrorRef for C error bindings. |
| 1396 | inline LLVMErrorRef wrap(Error Err) { |
| 1397 | return reinterpret_cast<LLVMErrorRef>(Err.takePayload().release()); |
| 1398 | } |
| 1399 | |
| 1400 | /// Conversion from LLVMErrorRef to Error for C error bindings. |
| 1401 | inline Error unwrap(LLVMErrorRef ErrRef) { |
| 1402 | return Error(std::unique_ptr<ErrorInfoBase>( |
| 1403 | reinterpret_cast<ErrorInfoBase *>(ErrRef))); |
| 1404 | } |
| 1405 | |
| 1406 | } // end namespace llvm |
| 1407 | |
| 1408 | #endif // LLVM_SUPPORT_ERROR_H |