1 //===-- LLVMTargetMachine.cpp - Implement the LLVMTargetMachine class -----===// 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 LLVMTargetMachine class. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "llvm/Analysis/Passes.h" 14 #include "llvm/CodeGen/AsmPrinter.h" 15 #include "llvm/CodeGen/BasicTTIImpl.h" 16 #include "llvm/CodeGen/MachineModuleInfo.h" 17 #include "llvm/CodeGen/Passes.h" 18 #include "llvm/CodeGen/TargetPassConfig.h" 19 #include "llvm/IR/LegacyPassManager.h" 20 #include "llvm/MC/MCAsmBackend.h" 21 #include "llvm/MC/MCAsmInfo.h" 22 #include "llvm/MC/MCCodeEmitter.h" 23 #include "llvm/MC/MCContext.h" 24 #include "llvm/MC/MCInstrInfo.h" 25 #include "llvm/MC/MCObjectWriter.h" 26 #include "llvm/MC/MCStreamer.h" 27 #include "llvm/MC/MCSubtargetInfo.h" 28 #include "llvm/Support/CommandLine.h" 29 #include "llvm/Support/ErrorHandling.h" 30 #include "llvm/Support/FormattedStream.h" 31 #include "llvm/Support/TargetRegistry.h" 32 #include "llvm/Target/TargetLoweringObjectFile.h" 33 #include "llvm/Target/TargetMachine.h" 34 #include "llvm/Target/TargetOptions.h" 35 using namespace llvm; 36 37 static cl::opt<bool> EnableTrapUnreachable("trap-unreachable", 38 cl::Hidden, cl::ZeroOrMore, cl::init(false), 39 cl::desc("Enable generating trap for unreachable")); 40 41 void LLVMTargetMachine::initAsmInfo() { 42 MRI.reset(TheTarget.createMCRegInfo(getTargetTriple().str())); 43 assert(MRI && "Unable to create reg info"); 44 MII.reset(TheTarget.createMCInstrInfo()); 45 assert(MII && "Unable to create instruction info"); 46 // FIXME: Having an MCSubtargetInfo on the target machine is a hack due 47 // to some backends having subtarget feature dependent module level 48 // code generation. This is similar to the hack in the AsmPrinter for 49 // module level assembly etc. 50 STI.reset(TheTarget.createMCSubtargetInfo( 51 getTargetTriple().str(), getTargetCPU(), getTargetFeatureString())); 52 assert(STI && "Unable to create subtarget info"); 53 54 MCAsmInfo *TmpAsmInfo = TheTarget.createMCAsmInfo( 55 *MRI, getTargetTriple().str(), Options.MCOptions); 56 // TargetSelect.h moved to a different directory between LLVM 2.9 and 3.0, 57 // and if the old one gets included then MCAsmInfo will be NULL and 58 // we'll crash later. 59 // Provide the user with a useful error message about what's wrong. 60 assert(TmpAsmInfo && "MCAsmInfo not initialized. " 61 "Make sure you include the correct TargetSelect.h" 62 "and that InitializeAllTargetMCs() is being invoked!"); 63 64 if (Options.BinutilsVersion.first > 0) 65 TmpAsmInfo->setBinutilsVersion(Options.BinutilsVersion); 66 67 if (Options.DisableIntegratedAS) 68 TmpAsmInfo->setUseIntegratedAssembler(false); 69 70 TmpAsmInfo->setPreserveAsmComments(Options.MCOptions.PreserveAsmComments); 71 72 TmpAsmInfo->setCompressDebugSections(Options.CompressDebugSections); 73 74 TmpAsmInfo->setRelaxELFRelocations(Options.RelaxELFRelocations); 75 76 if (Options.ExceptionModel != ExceptionHandling::None) 77 TmpAsmInfo->setExceptionsType(Options.ExceptionModel); 78 79 AsmInfo.reset(TmpAsmInfo); 80 } 81 82 LLVMTargetMachine::LLVMTargetMachine(const Target &T, 83 StringRef DataLayoutString, 84 const Triple &TT, StringRef CPU, 85 StringRef FS, const TargetOptions &Options, 86 Reloc::Model RM, CodeModel::Model CM, 87 CodeGenOpt::Level OL) 88 : TargetMachine(T, DataLayoutString, TT, CPU, FS, Options) { 89 this->RM = RM; 90 this->CMModel = CM; 91 this->OptLevel = OL; 92 93 if (EnableTrapUnreachable) 94 this->Options.TrapUnreachable = true; 95 } 96 97 TargetTransformInfo 98 LLVMTargetMachine::getTargetTransformInfo(const Function &F) { 99 return TargetTransformInfo(BasicTTIImpl(this, F)); 100 } 101 102 /// addPassesToX helper drives creation and initialization of TargetPassConfig. 103 static TargetPassConfig * 104 addPassesToGenerateCode(LLVMTargetMachine &TM, PassManagerBase &PM, 105 bool DisableVerify, 106 MachineModuleInfoWrapperPass &MMIWP) { 107 // Targets may override createPassConfig to provide a target-specific 108 // subclass. 109 TargetPassConfig *PassConfig = TM.createPassConfig(PM); 110 // Set PassConfig options provided by TargetMachine. 111 PassConfig->setDisableVerify(DisableVerify); 112 PM.add(PassConfig); 113 PM.add(&MMIWP); 114 115 if (PassConfig->addISelPasses()) 116 return nullptr; 117 PassConfig->addMachinePasses(); 118 PassConfig->setInitialized(); 119 return PassConfig; 120 } 121 122 bool LLVMTargetMachine::addAsmPrinter(PassManagerBase &PM, 123 raw_pwrite_stream &Out, 124 raw_pwrite_stream *DwoOut, 125 CodeGenFileType FileType, 126 MCContext &Context) { 127 Expected<std::unique_ptr<MCStreamer>> MCStreamerOrErr = 128 createMCStreamer(Out, DwoOut, FileType, Context); 129 if (auto Err = MCStreamerOrErr.takeError()) 130 return true; 131 132 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful. 133 FunctionPass *Printer = 134 getTarget().createAsmPrinter(*this, std::move(*MCStreamerOrErr)); 135 if (!Printer) 136 return true; 137 138 PM.add(Printer); 139 return false; 140 } 141 142 Expected<std::unique_ptr<MCStreamer>> LLVMTargetMachine::createMCStreamer( 143 raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut, CodeGenFileType FileType, 144 MCContext &Context) { 145 if (Options.MCOptions.MCSaveTempLabels) 146 Context.setAllowTemporaryLabels(false); 147 148 const MCSubtargetInfo &STI = *getMCSubtargetInfo(); 149 const MCAsmInfo &MAI = *getMCAsmInfo(); 150 const MCRegisterInfo &MRI = *getMCRegisterInfo(); 151 const MCInstrInfo &MII = *getMCInstrInfo(); 152 153 std::unique_ptr<MCStreamer> AsmStreamer; 154 155 switch (FileType) { 156 case CGFT_AssemblyFile: { 157 MCInstPrinter *InstPrinter = getTarget().createMCInstPrinter( 158 getTargetTriple(), MAI.getAssemblerDialect(), MAI, MII, MRI); 159 160 // Create a code emitter if asked to show the encoding. 161 std::unique_ptr<MCCodeEmitter> MCE; 162 if (Options.MCOptions.ShowMCEncoding) 163 MCE.reset(getTarget().createMCCodeEmitter(MII, MRI, Context)); 164 165 std::unique_ptr<MCAsmBackend> MAB( 166 getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions)); 167 auto FOut = std::make_unique<formatted_raw_ostream>(Out); 168 MCStreamer *S = getTarget().createAsmStreamer( 169 Context, std::move(FOut), Options.MCOptions.AsmVerbose, 170 Options.MCOptions.MCUseDwarfDirectory, InstPrinter, std::move(MCE), 171 std::move(MAB), Options.MCOptions.ShowMCInst); 172 AsmStreamer.reset(S); 173 break; 174 } 175 case CGFT_ObjectFile: { 176 // Create the code emitter for the target if it exists. If not, .o file 177 // emission fails. 178 MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(MII, MRI, Context); 179 if (!MCE) 180 return make_error<StringError>("createMCCodeEmitter failed", 181 inconvertibleErrorCode()); 182 MCAsmBackend *MAB = 183 getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions); 184 if (!MAB) 185 return make_error<StringError>("createMCAsmBackend failed", 186 inconvertibleErrorCode()); 187 188 Triple T(getTargetTriple().str()); 189 AsmStreamer.reset(getTarget().createMCObjectStreamer( 190 T, Context, std::unique_ptr<MCAsmBackend>(MAB), 191 DwoOut ? MAB->createDwoObjectWriter(Out, *DwoOut) 192 : MAB->createObjectWriter(Out), 193 std::unique_ptr<MCCodeEmitter>(MCE), STI, Options.MCOptions.MCRelaxAll, 194 Options.MCOptions.MCIncrementalLinkerCompatible, 195 /*DWARFMustBeAtTheEnd*/ true)); 196 break; 197 } 198 case CGFT_Null: 199 // The Null output is intended for use for performance analysis and testing, 200 // not real users. 201 AsmStreamer.reset(getTarget().createNullStreamer(Context)); 202 break; 203 } 204 205 return std::move(AsmStreamer); 206 } 207 208 bool LLVMTargetMachine::addPassesToEmitFile( 209 PassManagerBase &PM, raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut, 210 CodeGenFileType FileType, bool DisableVerify, 211 MachineModuleInfoWrapperPass *MMIWP) { 212 // Add common CodeGen passes. 213 if (!MMIWP) 214 MMIWP = new MachineModuleInfoWrapperPass(this); 215 TargetPassConfig *PassConfig = 216 addPassesToGenerateCode(*this, PM, DisableVerify, *MMIWP); 217 if (!PassConfig) 218 return true; 219 220 if (TargetPassConfig::willCompleteCodeGenPipeline()) { 221 if (addAsmPrinter(PM, Out, DwoOut, FileType, MMIWP->getMMI().getContext())) 222 return true; 223 } else { 224 // MIR printing is redundant with -filetype=null. 225 if (FileType != CGFT_Null) 226 PM.add(createPrintMIRPass(Out)); 227 } 228 229 PM.add(createFreeMachineFunctionPass()); 230 return false; 231 } 232 233 /// addPassesToEmitMC - Add passes to the specified pass manager to get 234 /// machine code emitted with the MCJIT. This method returns true if machine 235 /// code is not supported. It fills the MCContext Ctx pointer which can be 236 /// used to build custom MCStreamer. 237 /// 238 bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM, MCContext *&Ctx, 239 raw_pwrite_stream &Out, 240 bool DisableVerify) { 241 // Add common CodeGen passes. 242 MachineModuleInfoWrapperPass *MMIWP = new MachineModuleInfoWrapperPass(this); 243 TargetPassConfig *PassConfig = 244 addPassesToGenerateCode(*this, PM, DisableVerify, *MMIWP); 245 if (!PassConfig) 246 return true; 247 assert(TargetPassConfig::willCompleteCodeGenPipeline() && 248 "Cannot emit MC with limited codegen pipeline"); 249 250 Ctx = &MMIWP->getMMI().getContext(); 251 if (Options.MCOptions.MCSaveTempLabels) 252 Ctx->setAllowTemporaryLabels(false); 253 254 // Create the code emitter for the target if it exists. If not, .o file 255 // emission fails. 256 const MCSubtargetInfo &STI = *getMCSubtargetInfo(); 257 const MCRegisterInfo &MRI = *getMCRegisterInfo(); 258 MCCodeEmitter *MCE = 259 getTarget().createMCCodeEmitter(*getMCInstrInfo(), MRI, *Ctx); 260 MCAsmBackend *MAB = 261 getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions); 262 if (!MCE || !MAB) 263 return true; 264 265 const Triple &T = getTargetTriple(); 266 std::unique_ptr<MCStreamer> AsmStreamer(getTarget().createMCObjectStreamer( 267 T, *Ctx, std::unique_ptr<MCAsmBackend>(MAB), MAB->createObjectWriter(Out), 268 std::unique_ptr<MCCodeEmitter>(MCE), STI, Options.MCOptions.MCRelaxAll, 269 Options.MCOptions.MCIncrementalLinkerCompatible, 270 /*DWARFMustBeAtTheEnd*/ true)); 271 272 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful. 273 FunctionPass *Printer = 274 getTarget().createAsmPrinter(*this, std::move(AsmStreamer)); 275 if (!Printer) 276 return true; 277 278 PM.add(Printer); 279 PM.add(createFreeMachineFunctionPass()); 280 281 return false; // success! 282 } 283