llvm/lib/CodeGen/LLVMTargetMachine.cpp

   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 void LLVMTargetMachine::initAsmInfo() {
  41   MRI.reset(TheTarget.createMCRegInfo(getTargetTriple().str()));
  42   assert(MRI && "Unable to create reg info");
  43   MII.reset(TheTarget.createMCInstrInfo());
  44   assert(MII && "Unable to create instruction info");
  45   // FIXME: Having an MCSubtargetInfo on the target machine is a hack due
  46   // to some backends having subtarget feature dependent module level
  47   // code generation. This is similar to the hack in the AsmPrinter for
  48   // module level assembly etc.
  49   STI.reset(TheTarget.createMCSubtargetInfo(
  50       getTargetTriple().str(), getTargetCPU(), getTargetFeatureString()));
  51   assert(STI && "Unable to create subtarget info");
  52
  53   MCAsmInfo *TmpAsmInfo = TheTarget.createMCAsmInfo(
  54       *MRI, getTargetTriple().str(), Options.MCOptions);
  55   // TargetSelect.h moved to a different directory between LLVM 2.9 and 3.0,
  56   // and if the old one gets included then MCAsmInfo will be NULL and
  57   // we'll crash later.
  58   // Provide the user with a useful error message about what's wrong.
  59   assert(TmpAsmInfo && "MCAsmInfo not initialized. "
  60          "Make sure you include the correct TargetSelect.h"
  61          "and that InitializeAllTargetMCs() is being invoked!");
  62
  63   if (Options.BinutilsVersion.first > 0)
  64     TmpAsmInfo->setBinutilsVersion(Options.BinutilsVersion);
  65
  66   if (Options.DisableIntegratedAS) {
  67     TmpAsmInfo->setUseIntegratedAssembler(false);
  68     // If there is explict option disable integratedAS, we can't use it for
  69     // inlineasm either.
  70     TmpAsmInfo->setParseInlineAsmUsingAsmParser(false);
  71   }
  72
  73   TmpAsmInfo->setPreserveAsmComments(Options.MCOptions.PreserveAsmComments);
  74
  75   TmpAsmInfo->setCompressDebugSections(Options.CompressDebugSections);
  76
  77   TmpAsmInfo->setRelaxELFRelocations(Options.RelaxELFRelocations);
  78
  79   if (Options.ExceptionModel != ExceptionHandling::None)
  80     TmpAsmInfo->setExceptionsType(Options.ExceptionModel);
  81
  82   AsmInfo.reset(TmpAsmInfo);
  83 }
  84
  85 LLVMTargetMachine::LLVMTargetMachine(const Target &T,
  86                                      StringRef DataLayoutString,
  87                                      const Triple &TT, StringRef CPU,
  88                                      StringRef FS, const TargetOptions &Options,
  89                                      Reloc::Model RM, CodeModel::Model CM,
  90                                      CodeGenOpt::Level OL)
  91     : TargetMachine(T, DataLayoutString, TT, CPU, FS, Options) {
  92   this->RM = RM;
  93   this->CMModel = CM;
  94   this->OptLevel = OL;
  95
  96   if (EnableTrapUnreachable)
  97     this->Options.TrapUnreachable = true;
  98 }
  99
 100 TargetTransformInfo
 101 LLVMTargetMachine::getTargetTransformInfo(const Function &F) const {
 102   return TargetTransformInfo(BasicTTIImpl(this, F));
 103 }
 104
 105 /// addPassesToX helper drives creation and initialization of TargetPassConfig.
 106 static TargetPassConfig *
 107 addPassesToGenerateCode(LLVMTargetMachine &TM, PassManagerBase &PM,
 108                         bool DisableVerify,
 109                         MachineModuleInfoWrapperPass &MMIWP) {
 110   // Targets may override createPassConfig to provide a target-specific
 111   // subclass.
 112   TargetPassConfig *PassConfig = TM.createPassConfig(PM);
 113   // Set PassConfig options provided by TargetMachine.
 114   PassConfig->setDisableVerify(DisableVerify);
 115   PM.add(PassConfig);
 116   PM.add(&MMIWP);
 117
 118   if (PassConfig->addISelPasses())
 119     return nullptr;
 120   PassConfig->addMachinePasses();
 121   PassConfig->setInitialized();
 122   return PassConfig;
 123 }
 124
 125 bool LLVMTargetMachine::addAsmPrinter(PassManagerBase &PM,
 126                                       raw_pwrite_stream &Out,
 127                                       raw_pwrite_stream *DwoOut,
 128                                       CodeGenFileType FileType,
 129                                       MCContext &Context) {
 130   Expected<std::unique_ptr<MCStreamer>> MCStreamerOrErr =
 131       createMCStreamer(Out, DwoOut, FileType, Context);
 132   if (auto Err = MCStreamerOrErr.takeError())
 133     return true;
 134
 135   // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
 136   FunctionPass *Printer =
 137       getTarget().createAsmPrinter(*this, std::move(*MCStreamerOrErr));
 138   if (!Printer)
 139     return true;
 140
 141   PM.add(Printer);
 142   return false;
 143 }
 144
 145 Expected<std::unique_ptr<MCStreamer>> LLVMTargetMachine::createMCStreamer(
 146     raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut, CodeGenFileType FileType,
 147     MCContext &Context) {
 148   if (Options.MCOptions.MCSaveTempLabels)
 149     Context.setAllowTemporaryLabels(false);
 150
 151   const MCSubtargetInfo &STI = *getMCSubtargetInfo();
 152   const MCAsmInfo &MAI = *getMCAsmInfo();
 153   const MCRegisterInfo &MRI = *getMCRegisterInfo();
 154   const MCInstrInfo &MII = *getMCInstrInfo();
 155
 156   std::unique_ptr<MCStreamer> AsmStreamer;
 157
 158   switch (FileType) {
 159   case CGFT_AssemblyFile: {
 160     MCInstPrinter *InstPrinter = getTarget().createMCInstPrinter(
 161         getTargetTriple(), MAI.getAssemblerDialect(), MAI, MII, MRI);
 162
 163     // Create a code emitter if asked to show the encoding.
 164     std::unique_ptr<MCCodeEmitter> MCE;
 165     if (Options.MCOptions.ShowMCEncoding)
 166       MCE.reset(getTarget().createMCCodeEmitter(MII, Context));
 167
 168     bool UseDwarfDirectory = false;
 169     switch (Options.MCOptions.MCUseDwarfDirectory) {
 170     case MCTargetOptions::DisableDwarfDirectory:
 171       UseDwarfDirectory = false;
 172       break;
 173     case MCTargetOptions::EnableDwarfDirectory:
 174       UseDwarfDirectory = true;
 175       break;
 176     case MCTargetOptions::DefaultDwarfDirectory:
 177       UseDwarfDirectory = MAI.enableDwarfFileDirectoryDefault();
 178       break;
 179     }
 180
 181     std::unique_ptr<MCAsmBackend> MAB(
 182         getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions));
 183     auto FOut = std::make_unique<formatted_raw_ostream>(Out);
 184     MCStreamer *S = getTarget().createAsmStreamer(
 185         Context, std::move(FOut), Options.MCOptions.AsmVerbose,
 186         UseDwarfDirectory, InstPrinter, std::move(MCE), std::move(MAB),
 187         Options.MCOptions.ShowMCInst);
 188     AsmStreamer.reset(S);
 189     break;
 190   }
 191   case CGFT_ObjectFile: {
 192     // Create the code emitter for the target if it exists.  If not, .o file
 193     // emission fails.
 194     MCCodeEmitter *MCE = getTarget().createMCCodeEmitter(MII, Context);
 195     if (!MCE)
 196       return make_error<StringError>("createMCCodeEmitter failed",
 197                                      inconvertibleErrorCode());
 198     MCAsmBackend *MAB =
 199         getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions);
 200     if (!MAB)
 201       return make_error<StringError>("createMCAsmBackend failed",
 202                                      inconvertibleErrorCode());
 203
 204     Triple T(getTargetTriple().str());
 205     AsmStreamer.reset(getTarget().createMCObjectStreamer(
 206         T, Context, std::unique_ptr<MCAsmBackend>(MAB),
 207         DwoOut ? MAB->createDwoObjectWriter(Out, *DwoOut)
 208                : MAB->createObjectWriter(Out),
 209         std::unique_ptr<MCCodeEmitter>(MCE), STI, Options.MCOptions.MCRelaxAll,
 210         Options.MCOptions.MCIncrementalLinkerCompatible,
 211         /*DWARFMustBeAtTheEnd*/ true));
 212     break;
 213   }
 214   case CGFT_Null:
 215     // The Null output is intended for use for performance analysis and testing,
 216     // not real users.
 217     AsmStreamer.reset(getTarget().createNullStreamer(Context));
 218     break;
 219   }
 220
 221   return std::move(AsmStreamer);
 222 }
 223
 224 bool LLVMTargetMachine::addPassesToEmitFile(
 225     PassManagerBase &PM, raw_pwrite_stream &Out, raw_pwrite_stream *DwoOut,
 226     CodeGenFileType FileType, bool DisableVerify,
 227     MachineModuleInfoWrapperPass *MMIWP) {
 228   // Add common CodeGen passes.
 229   if (!MMIWP)
 230     MMIWP = new MachineModuleInfoWrapperPass(this);
 231   TargetPassConfig *PassConfig =
 232       addPassesToGenerateCode(*this, PM, DisableVerify, *MMIWP);
 233   if (!PassConfig)
 234     return true;
 235
 236   if (TargetPassConfig::willCompleteCodeGenPipeline()) {
 237     if (addAsmPrinter(PM, Out, DwoOut, FileType, MMIWP->getMMI().getContext()))
 238       return true;
 239   } else {
 240     // MIR printing is redundant with -filetype=null.
 241     if (FileType != CGFT_Null)
 242       PM.add(createPrintMIRPass(Out));
 243   }
 244
 245   PM.add(createFreeMachineFunctionPass());
 246   return false;
 247 }
 248
 249 /// addPassesToEmitMC - Add passes to the specified pass manager to get
 250 /// machine code emitted with the MCJIT. This method returns true if machine
 251 /// code is not supported. It fills the MCContext Ctx pointer which can be
 252 /// used to build custom MCStreamer.
 253 ///
 254 bool LLVMTargetMachine::addPassesToEmitMC(PassManagerBase &PM, MCContext *&Ctx,
 255                                           raw_pwrite_stream &Out,
 256                                           bool DisableVerify) {
 257   // Add common CodeGen passes.
 258   MachineModuleInfoWrapperPass *MMIWP = new MachineModuleInfoWrapperPass(this);
 259   TargetPassConfig *PassConfig =
 260       addPassesToGenerateCode(*this, PM, DisableVerify, *MMIWP);
 261   if (!PassConfig)
 262     return true;
 263   assert(TargetPassConfig::willCompleteCodeGenPipeline() &&
 264          "Cannot emit MC with limited codegen pipeline");
 265
 266   Ctx = &MMIWP->getMMI().getContext();
 267   // libunwind is unable to load compact unwind dynamically, so we must generate
 268   // DWARF unwind info for the JIT.
 269   Options.MCOptions.EmitDwarfUnwind = EmitDwarfUnwindType::Always;
 270   if (Options.MCOptions.MCSaveTempLabels)
 271     Ctx->setAllowTemporaryLabels(false);
 272
 273   // Create the code emitter for the target if it exists.  If not, .o file
 274   // emission fails.
 275   const MCSubtargetInfo &STI = *getMCSubtargetInfo();
 276   const MCRegisterInfo &MRI = *getMCRegisterInfo();
 277   std::unique_ptr<MCCodeEmitter> MCE(
 278       getTarget().createMCCodeEmitter(*getMCInstrInfo(), *Ctx));
 279   std::unique_ptr<MCAsmBackend> MAB(
 280       getTarget().createMCAsmBackend(STI, MRI, Options.MCOptions));
 281   if (!MCE || !MAB)
 282     return true;
 283
 284   const Triple &T = getTargetTriple();
 285   std::unique_ptr<MCStreamer> AsmStreamer(getTarget().createMCObjectStreamer(
 286       T, *Ctx, std::move(MAB), MAB->createObjectWriter(Out), std::move(MCE),
 287       STI, Options.MCOptions.MCRelaxAll,
 288       Options.MCOptions.MCIncrementalLinkerCompatible,
 289       /*DWARFMustBeAtTheEnd*/ true));
 290
 291   // Create the AsmPrinter, which takes ownership of AsmStreamer if successful.
 292   FunctionPass *Printer =
 293       getTarget().createAsmPrinter(*this, std::move(AsmStreamer));
 294   if (!Printer)
 295     return true;
 296
 297   PM.add(Printer);
 298   PM.add(createFreeMachineFunctionPass());
 299
 300   return false; // success!
 301 }