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/MCRegisterInfo.h" 27 #include "llvm/MC/MCStreamer.h" 28 #include "llvm/MC/MCSubtargetInfo.h" 29 #include "llvm/MC/TargetRegistry.h" 30 #include "llvm/Support/CommandLine.h" 31 #include "llvm/Support/FormattedStream.h" 32 #include "llvm/Target/TargetMachine.h" 33 #include "llvm/Target/TargetOptions.h" 34 using namespace llvm; 35 36 static cl::opt<bool> 37 EnableTrapUnreachable("trap-unreachable", cl::Hidden, 38 cl::desc("Enable generating trap for unreachable")); 39 40 static cl::opt<bool> EnableNoTrapAfterNoreturn( 41 "no-trap-after-noreturn", cl::Hidden, 42 cl::desc("Do not emit a trap instruction for 'unreachable' IR instructions " 43 "after noreturn calls, even if --trap-unreachable is set.")); 44 45 void LLVMTargetMachine::initAsmInfo() { 46 MRI.reset(TheTarget.createMCRegInfo(getTargetTriple().str())); 47 assert(MRI && "Unable to create reg info"); 48 MII.reset(TheTarget.createMCInstrInfo()); 49 assert(MII && "Unable to create instruction info"); 50 // FIXME: Having an MCSubtargetInfo on the target machine is a hack due 51 // to some backends having subtarget feature dependent module level 52 // code generation. This is similar to the hack in the AsmPrinter for 53 // module level assembly etc. 54 STI.reset(TheTarget.createMCSubtargetInfo( 55 getTargetTriple().str(), getTargetCPU(), getTargetFeatureString())); 56 assert(STI && "Unable to create subtarget info"); 57 58 MCAsmInfo *TmpAsmInfo = TheTarget.createMCAsmInfo( 59 *MRI, getTargetTriple().str(), Options.MCOptions); 60 // TargetSelect.h moved to a different directory between LLVM 2.9 and 3.0, 61 // and if the old one gets included then MCAsmInfo will be NULL and 62 // we'll crash later. 63 // Provide the user with a useful error message about what's wrong. 64 assert(TmpAsmInfo && "MCAsmInfo not initialized. " 65 "Make sure you include the correct TargetSelect.h" 66 "and that InitializeAllTargetMCs() is being invoked!"); 67 68 if (Options.BinutilsVersion.first > 0) 69 TmpAsmInfo->setBinutilsVersion(Options.BinutilsVersion); 70 71 if (Options.DisableIntegratedAS) { 72 TmpAsmInfo->setUseIntegratedAssembler(false); 73 // If there is explict option disable integratedAS, we can't use it for 74 // inlineasm either. 75 TmpAsmInfo->setParseInlineAsmUsingAsmParser(false); 76 } 77 78 TmpAsmInfo->setPreserveAsmComments(Options.MCOptions.PreserveAsmComments); 79 80 TmpAsmInfo->setFullRegisterNames(Options.MCOptions.PPCUseFullRegisterNames); 81 82 if (Options.ExceptionModel != ExceptionHandling::None) 83 TmpAsmInfo->setExceptionsType(Options.ExceptionModel); 84 85 AsmInfo.reset(TmpAsmInfo); 86 } 87 88 LLVMTargetMachine::LLVMTargetMachine(const Target &T, 89 StringRef DataLayoutString, 90 const Triple &TT, StringRef CPU, 91 StringRef FS, const TargetOptions &Options, 92 Reloc::Model RM, CodeModel::Model CM, 93 CodeGenOptLevel OL) 94 : TargetMachine(T, DataLayoutString, TT, CPU, FS, Options) { 95 this->RM = RM; 96 this->CMModel = CM; 97 this->OptLevel = OL; 98 99 if (EnableTrapUnreachable) 100 this->Options.TrapUnreachable = true; 101 if (EnableNoTrapAfterNoreturn) 102 this->Options.NoTrapAfterNoreturn = true; 103 } 104 105 TargetTransformInfo 106 LLVMTargetMachine::getTargetTransformInfo(const Function &F) const { 107 return TargetTransformInfo(BasicTTIImpl(this, F)); 108 } 109 110 /// addPassesToX helper drives creation and initialization of TargetPassConfig. 111 static TargetPassConfig * 112 addPassesToGenerateCode(LLVMTargetMachine &TM, PassManagerBase &PM, 113 bool DisableVerify, 114 MachineModuleInfoWrapperPass &MMIWP) { 115 // Targets may override createPassConfig to provide a target-specific 116 // subclass. 117 TargetPassConfig *PassConfig = TM.createPassConfig(PM); 118 // Set PassConfig options provided by TargetMachine. 119 PassConfig->setDisableVerify(DisableVerify); 120 PM.add(PassConfig); 121 PM.add(&MMIWP); 122 123 if (PassConfig->addISelPasses()) 124 return nullptr; 125 PassConfig->addMachinePasses(); 126 PassConfig->setInitialized(); 127 return PassConfig; 128 } 129 130 bool LLVMTargetMachine::addAsmPrinter(PassManagerBase &PM, 131 raw_pwrite_stream &Out, 132 raw_pwrite_stream *DwoOut, 133 CodeGenFileType FileType, 134 MCContext &Context) { 135 Expected<std::unique_ptr<MCStreamer>> MCStreamerOrErr = 136 createMCStreamer(Out, DwoOut, FileType, Context); 137 if (auto Err = MCStreamerOrErr.takeError()) 138 return true; 139 140 // Create the AsmPrinter, which takes ownership of AsmStreamer if successful. 141 FunctionPass *Printer = 142 getTarget().createAsmPrinter(*this, std::move(*MCStreamerOrErr)); 143 if (!Printer) 144 return true; 145 146 PM.add(Printer); 147 return false; 148 } 149 150 Expected<std::unique_ptr<MCStreamer>> LLVMTargetMachine::createMCStreamer( 151 raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut, CodeGenFileType FileType, 152 MCContext &Context) { 153 const MCSubtargetInfo &STI = *getMCSubtargetInfo(); 154 const MCAsmInfo &MAI = *getMCAsmInfo(); 155 const MCRegisterInfo &MRI = *getMCRegisterInfo(); 156 const MCInstrInfo &MII = *getMCInstrInfo(); 157 158 std::unique_ptr<MCStreamer> AsmStreamer; 159 160 switch (FileType) { 161 case CodeGenFileType::AssemblyFile: { 162 MCInstPrinter *InstPrinter = getTarget().createMCInstPrinter( 163 getTargetTriple(), MAI.getAssemblerDialect(), MAI, MII, MRI); 164 165 // Create a code emitter if asked to show the encoding. 166 std::unique_ptr<MCCodeEmitter> MCE; 167 if (Options.MCOptions.ShowMCEncoding) 168 MCE.reset(getTarget().createMCCodeEmitter(MII, Context)); 169 170 std::unique_ptr<MCAsmBackend> MAB( 171 getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions)); 172 auto FOut = std::make_unique<formatted_raw_ostream>(Out); 173 MCStreamer *S = getTarget().createAsmStreamer( 174 Context, std::move(FOut), InstPrinter, std::move(MCE), std::move(MAB)); 175 AsmStreamer.reset(S); 176 break; 177 } 178 case CodeGenFileType::ObjectFile: { 179 // Create the code emitter for the target if it exists. If not, .o file 180 // emission fails. 181 MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(MII, Context); 182 if (!MCE) 183 return make_error<StringError>("createMCCodeEmitter failed", 184 inconvertibleErrorCode()); 185 MCAsmBackend *MAB = 186 getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions); 187 if (!MAB) 188 return make_error<StringError>("createMCAsmBackend failed", 189 inconvertibleErrorCode()); 190 191 Triple T(getTargetTriple().str()); 192 AsmStreamer.reset(getTarget().createMCObjectStreamer( 193 T, Context, std::unique_ptr<MCAsmBackend>(MAB), 194 DwoOut ? MAB->createDwoObjectWriter(Out, *DwoOut) 195 : MAB->createObjectWriter(Out), 196 std::unique_ptr<MCCodeEmitter>(MCE), STI)); 197 break; 198 } 199 case CodeGenFileType::Null: 200 // The Null output is intended for use for performance analysis and testing, 201 // not real users. 202 AsmStreamer.reset(getTarget().createNullStreamer(Context)); 203 break; 204 } 205 206 return std::move(AsmStreamer); 207 } 208 209 bool LLVMTargetMachine::addPassesToEmitFile( 210 PassManagerBase &PM, raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut, 211 CodeGenFileType FileType, bool DisableVerify, 212 MachineModuleInfoWrapperPass *MMIWP) { 213 // Add common CodeGen passes. 214 if (!MMIWP) 215 MMIWP = new MachineModuleInfoWrapperPass(this); 216 TargetPassConfig *PassConfig = 217 addPassesToGenerateCode(*this, PM, DisableVerify, *MMIWP); 218 if (!PassConfig) 219 return true; 220 221 if (TargetPassConfig::willCompleteCodeGenPipeline()) { 222 if (addAsmPrinter(PM, Out, DwoOut, FileType, MMIWP->getMMI().getContext())) 223 return true; 224 } else { 225 // MIR printing is redundant with -filetype=null. 226 if (FileType != CodeGenFileType::Null) 227 PM.add(createPrintMIRPass(Out)); 228 } 229 230 PM.add(createFreeMachineFunctionPass()); 231 return false; 232 } 233 234 /// addPassesToEmitMC - Add passes to the specified pass manager to get 235 /// machine code emitted with the MCJIT. This method returns true if machine 236 /// code is not supported. It fills the MCContext Ctx pointer which can be 237 /// used to build custom MCStreamer. 238 /// 239 bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM, MCContext *&Ctx, 240 raw_pwrite_stream &Out, 241 bool DisableVerify) { 242 // Add common CodeGen passes. 243 MachineModuleInfoWrapperPass *MMIWP = new MachineModuleInfoWrapperPass(this); 244 TargetPassConfig *PassConfig = 245 addPassesToGenerateCode(*this, PM, DisableVerify, *MMIWP); 246 if (!PassConfig) 247 return true; 248 assert(TargetPassConfig::willCompleteCodeGenPipeline() && 249 "Cannot emit MC with limited codegen pipeline"); 250 251 Ctx = &MMIWP->getMMI().getContext(); 252 // libunwind is unable to load compact unwind dynamically, so we must generate 253 // DWARF unwind info for the JIT. 254 Options.MCOptions.EmitDwarfUnwind = EmitDwarfUnwindType::Always; 255 256 // Create the code emitter for the target if it exists. If not, .o file 257 // emission fails. 258 const MCSubtargetInfo &STI = *getMCSubtargetInfo(); 259 const MCRegisterInfo &MRI = *getMCRegisterInfo(); 260 std::unique_ptr<MCCodeEmitter> MCE( 261 getTarget().createMCCodeEmitter(*getMCInstrInfo(), *Ctx)); 262 MCAsmBackend *MAB = 263 getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions); 264 if (!MCE || !MAB) 265 return true; 266 267 const Triple &T = getTargetTriple(); 268 std::unique_ptr<MCStreamer> AsmStreamer(getTarget().createMCObjectStreamer( 269 T, *Ctx, std::unique_ptr<MCAsmBackend>(MAB), MAB->createObjectWriter(Out), 270 std::move(MCE), STI)); 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