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