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
initAsmInfo()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
LLVMTargetMachine(const Target & T,StringRef DataLayoutString,const Triple & TT,StringRef CPU,StringRef FS,const TargetOptions & Options,Reloc::Model RM,CodeModel::Model CM,CodeGenOpt::Level OL)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
getTargetTransformInfo(const Function & F)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 *
addPassesToGenerateCode(LLVMTargetMachine & TM,PassManagerBase & PM,bool DisableVerify,MachineModuleInfoWrapperPass & MMIWP)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
addAsmPrinter(PassManagerBase & PM,raw_pwrite_stream & Out,raw_pwrite_stream * DwoOut,CodeGenFileType FileType,MCContext & Context)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
createMCStreamer(raw_pwrite_stream & Out,raw_pwrite_stream * DwoOut,CodeGenFileType FileType,MCContext & Context)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
addPassesToEmitFile(PassManagerBase & PM,raw_pwrite_stream & Out,raw_pwrite_stream * DwoOut,CodeGenFileType FileType,bool DisableVerify,MachineModuleInfoWrapperPass * MMIWP)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 ///
addPassesToEmitMC(PassManagerBase & PM,MCContext * & Ctx,raw_pwrite_stream & Out,bool DisableVerify)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