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 |