1 //===- MIRParser.cpp - MIR serialization format parser implementation -----===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the class that parses the optional LLVM IR and machine
11 // functions that are stored in MIR files.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #include "llvm/CodeGen/MIRParser/MIRParser.h"
16 #include "MIParser.h"
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/STLExtras.h"
19 #include "llvm/ADT/StringMap.h"
20 #include "llvm/ADT/StringRef.h"
21 #include "llvm/AsmParser/Parser.h"
22 #include "llvm/AsmParser/SlotMapping.h"
23 #include "llvm/CodeGen/GlobalISel/RegisterBank.h"
24 #include "llvm/CodeGen/GlobalISel/RegisterBankInfo.h"
25 #include "llvm/CodeGen/MIRYamlMapping.h"
26 #include "llvm/CodeGen/MachineConstantPool.h"
27 #include "llvm/CodeGen/MachineFrameInfo.h"
28 #include "llvm/CodeGen/MachineFunction.h"
29 #include "llvm/CodeGen/MachineModuleInfo.h"
30 #include "llvm/CodeGen/MachineRegisterInfo.h"
31 #include "llvm/IR/BasicBlock.h"
32 #include "llvm/IR/DebugInfo.h"
33 #include "llvm/IR/DiagnosticInfo.h"
34 #include "llvm/IR/Instructions.h"
35 #include "llvm/IR/LLVMContext.h"
36 #include "llvm/IR/Module.h"
37 #include "llvm/IR/ValueSymbolTable.h"
38 #include "llvm/Support/LineIterator.h"
39 #include "llvm/Support/MemoryBuffer.h"
40 #include "llvm/Support/SMLoc.h"
41 #include "llvm/Support/SourceMgr.h"
42 #include "llvm/Support/YAMLTraits.h"
43 #include <memory>
44 
45 using namespace llvm;
46 
47 namespace llvm {
48 
49 /// This class implements the parsing of LLVM IR that's embedded inside a MIR
50 /// file.
51 class MIRParserImpl {
52   SourceMgr SM;
53   StringRef Filename;
54   LLVMContext &Context;
55   StringMap<std::unique_ptr<yaml::MachineFunction>> Functions;
56   SlotMapping IRSlots;
57   /// Maps from register class names to register classes.
58   Name2RegClassMap Names2RegClasses;
59   /// Maps from register bank names to register banks.
60   Name2RegBankMap Names2RegBanks;
61 
62 public:
63   MIRParserImpl(std::unique_ptr<MemoryBuffer> Contents, StringRef Filename,
64                 LLVMContext &Context);
65 
66   void reportDiagnostic(const SMDiagnostic &Diag);
67 
68   /// Report an error with the given message at unknown location.
69   ///
70   /// Always returns true.
71   bool error(const Twine &Message);
72 
73   /// Report an error with the given message at the given location.
74   ///
75   /// Always returns true.
76   bool error(SMLoc Loc, const Twine &Message);
77 
78   /// Report a given error with the location translated from the location in an
79   /// embedded string literal to a location in the MIR file.
80   ///
81   /// Always returns true.
82   bool error(const SMDiagnostic &Error, SMRange SourceRange);
83 
84   /// Try to parse the optional LLVM module and the machine functions in the MIR
85   /// file.
86   ///
87   /// Return null if an error occurred.
88   std::unique_ptr<Module> parse();
89 
90   /// Parse the machine function in the current YAML document.
91   ///
92   /// \param NoLLVMIR - set to true when the MIR file doesn't have LLVM IR.
93   /// A dummy IR function is created and inserted into the given module when
94   /// this parameter is true.
95   ///
96   /// Return true if an error occurred.
97   bool parseMachineFunction(yaml::Input &In, Module &M, bool NoLLVMIR);
98 
99   /// Initialize the machine function to the state that's described in the MIR
100   /// file.
101   ///
102   /// Return true if error occurred.
103   bool initializeMachineFunction(MachineFunction &MF);
104 
105   bool parseRegisterInfo(PerFunctionMIParsingState &PFS,
106                          const yaml::MachineFunction &YamlMF);
107 
108   bool setupRegisterInfo(const PerFunctionMIParsingState &PFS,
109                          const yaml::MachineFunction &YamlMF);
110 
111   bool initializeFrameInfo(PerFunctionMIParsingState &PFS,
112                            const yaml::MachineFunction &YamlMF);
113 
114   bool parseCalleeSavedRegister(PerFunctionMIParsingState &PFS,
115                                 std::vector<CalleeSavedInfo> &CSIInfo,
116                                 const yaml::StringValue &RegisterSource,
117                                 int FrameIdx);
118 
119   bool parseStackObjectsDebugInfo(PerFunctionMIParsingState &PFS,
120                                   const yaml::MachineStackObject &Object,
121                                   int FrameIdx);
122 
123   bool initializeConstantPool(PerFunctionMIParsingState &PFS,
124                               MachineConstantPool &ConstantPool,
125                               const yaml::MachineFunction &YamlMF);
126 
127   bool initializeJumpTableInfo(PerFunctionMIParsingState &PFS,
128                                const yaml::MachineJumpTable &YamlJTI);
129 
130 private:
131   bool parseMDNode(PerFunctionMIParsingState &PFS, MDNode *&Node,
132                    const yaml::StringValue &Source);
133 
134   bool parseMBBReference(PerFunctionMIParsingState &PFS,
135                          MachineBasicBlock *&MBB,
136                          const yaml::StringValue &Source);
137 
138   /// Return a MIR diagnostic converted from an MI string diagnostic.
139   SMDiagnostic diagFromMIStringDiag(const SMDiagnostic &Error,
140                                     SMRange SourceRange);
141 
142   /// Return a MIR diagnostic converted from a diagnostic located in a YAML
143   /// block scalar string.
144   SMDiagnostic diagFromBlockStringDiag(const SMDiagnostic &Error,
145                                        SMRange SourceRange);
146 
147   /// Create an empty function with the given name.
148   void createDummyFunction(StringRef Name, Module &M);
149 
150   void initNames2RegClasses(const MachineFunction &MF);
151   void initNames2RegBanks(const MachineFunction &MF);
152 
153   /// Check if the given identifier is a name of a register class.
154   ///
155   /// Return null if the name isn't a register class.
156   const TargetRegisterClass *getRegClass(const MachineFunction &MF,
157                                          StringRef Name);
158 
159   /// Check if the given identifier is a name of a register bank.
160   ///
161   /// Return null if the name isn't a register bank.
162   const RegisterBank *getRegBank(const MachineFunction &MF, StringRef Name);
163 
164   void computeFunctionProperties(MachineFunction &MF);
165 };
166 
167 } // end namespace llvm
168 
169 MIRParserImpl::MIRParserImpl(std::unique_ptr<MemoryBuffer> Contents,
170                              StringRef Filename, LLVMContext &Context)
171     : SM(), Filename(Filename), Context(Context) {
172   SM.AddNewSourceBuffer(std::move(Contents), SMLoc());
173 }
174 
175 bool MIRParserImpl::error(const Twine &Message) {
176   Context.diagnose(DiagnosticInfoMIRParser(
177       DS_Error, SMDiagnostic(Filename, SourceMgr::DK_Error, Message.str())));
178   return true;
179 }
180 
181 bool MIRParserImpl::error(SMLoc Loc, const Twine &Message) {
182   Context.diagnose(DiagnosticInfoMIRParser(
183       DS_Error, SM.GetMessage(Loc, SourceMgr::DK_Error, Message)));
184   return true;
185 }
186 
187 bool MIRParserImpl::error(const SMDiagnostic &Error, SMRange SourceRange) {
188   assert(Error.getKind() == SourceMgr::DK_Error && "Expected an error");
189   reportDiagnostic(diagFromMIStringDiag(Error, SourceRange));
190   return true;
191 }
192 
193 void MIRParserImpl::reportDiagnostic(const SMDiagnostic &Diag) {
194   DiagnosticSeverity Kind;
195   switch (Diag.getKind()) {
196   case SourceMgr::DK_Error:
197     Kind = DS_Error;
198     break;
199   case SourceMgr::DK_Warning:
200     Kind = DS_Warning;
201     break;
202   case SourceMgr::DK_Note:
203     Kind = DS_Note;
204     break;
205   }
206   Context.diagnose(DiagnosticInfoMIRParser(Kind, Diag));
207 }
208 
209 static void handleYAMLDiag(const SMDiagnostic &Diag, void *Context) {
210   reinterpret_cast<MIRParserImpl *>(Context)->reportDiagnostic(Diag);
211 }
212 
213 std::unique_ptr<Module> MIRParserImpl::parse() {
214   yaml::Input In(SM.getMemoryBuffer(SM.getMainFileID())->getBuffer(),
215                  /*Ctxt=*/nullptr, handleYAMLDiag, this);
216   In.setContext(&In);
217 
218   if (!In.setCurrentDocument()) {
219     if (In.error())
220       return nullptr;
221     // Create an empty module when the MIR file is empty.
222     return llvm::make_unique<Module>(Filename, Context);
223   }
224 
225   std::unique_ptr<Module> M;
226   bool NoLLVMIR = false;
227   // Parse the block scalar manually so that we can return unique pointer
228   // without having to go trough YAML traits.
229   if (const auto *BSN =
230           dyn_cast_or_null<yaml::BlockScalarNode>(In.getCurrentNode())) {
231     SMDiagnostic Error;
232     M = parseAssembly(MemoryBufferRef(BSN->getValue(), Filename), Error,
233                       Context, &IRSlots);
234     if (!M) {
235       reportDiagnostic(diagFromBlockStringDiag(Error, BSN->getSourceRange()));
236       return nullptr;
237     }
238     In.nextDocument();
239     if (!In.setCurrentDocument())
240       return M;
241   } else {
242     // Create an new, empty module.
243     M = llvm::make_unique<Module>(Filename, Context);
244     NoLLVMIR = true;
245   }
246 
247   // Parse the machine functions.
248   do {
249     if (parseMachineFunction(In, *M, NoLLVMIR))
250       return nullptr;
251     In.nextDocument();
252   } while (In.setCurrentDocument());
253 
254   return M;
255 }
256 
257 bool MIRParserImpl::parseMachineFunction(yaml::Input &In, Module &M,
258                                          bool NoLLVMIR) {
259   auto MF = llvm::make_unique<yaml::MachineFunction>();
260   yaml::EmptyContext Ctx;
261   yaml::yamlize(In, *MF, false, Ctx);
262   if (In.error())
263     return true;
264   auto FunctionName = MF->Name;
265   if (Functions.find(FunctionName) != Functions.end())
266     return error(Twine("redefinition of machine function '") + FunctionName +
267                  "'");
268   Functions.insert(std::make_pair(FunctionName, std::move(MF)));
269   if (NoLLVMIR)
270     createDummyFunction(FunctionName, M);
271   else if (!M.getFunction(FunctionName))
272     return error(Twine("function '") + FunctionName +
273                  "' isn't defined in the provided LLVM IR");
274   return false;
275 }
276 
277 void MIRParserImpl::createDummyFunction(StringRef Name, Module &M) {
278   auto &Context = M.getContext();
279   Function *F = cast<Function>(M.getOrInsertFunction(
280       Name, FunctionType::get(Type::getVoidTy(Context), false)));
281   BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
282   new UnreachableInst(Context, BB);
283 }
284 
285 static bool isSSA(const MachineFunction &MF) {
286   const MachineRegisterInfo &MRI = MF.getRegInfo();
287   for (unsigned I = 0, E = MRI.getNumVirtRegs(); I != E; ++I) {
288     unsigned Reg = TargetRegisterInfo::index2VirtReg(I);
289     if (!MRI.hasOneDef(Reg) && !MRI.def_empty(Reg))
290       return false;
291   }
292   return true;
293 }
294 
295 void MIRParserImpl::computeFunctionProperties(MachineFunction &MF) {
296   MachineFunctionProperties &Properties = MF.getProperties();
297 
298   bool HasPHI = false;
299   bool HasInlineAsm = false;
300   for (const MachineBasicBlock &MBB : MF) {
301     for (const MachineInstr &MI : MBB) {
302       if (MI.isPHI())
303         HasPHI = true;
304       if (MI.isInlineAsm())
305         HasInlineAsm = true;
306     }
307   }
308   if (!HasPHI)
309     Properties.set(MachineFunctionProperties::Property::NoPHIs);
310   MF.setHasInlineAsm(HasInlineAsm);
311 
312   if (isSSA(MF))
313     Properties.set(MachineFunctionProperties::Property::IsSSA);
314   else
315     Properties.reset(MachineFunctionProperties::Property::IsSSA);
316 
317   const MachineRegisterInfo &MRI = MF.getRegInfo();
318   if (MRI.getNumVirtRegs() == 0)
319     Properties.set(MachineFunctionProperties::Property::NoVRegs);
320 }
321 
322 bool MIRParserImpl::initializeMachineFunction(MachineFunction &MF) {
323   auto It = Functions.find(MF.getName());
324   if (It == Functions.end())
325     return error(Twine("no machine function information for function '") +
326                  MF.getName() + "' in the MIR file");
327   // TODO: Recreate the machine function.
328   initNames2RegClasses(MF);
329   initNames2RegBanks(MF);
330   const yaml::MachineFunction &YamlMF = *It->getValue();
331   if (YamlMF.Alignment)
332     MF.setAlignment(YamlMF.Alignment);
333   MF.setExposesReturnsTwice(YamlMF.ExposesReturnsTwice);
334 
335   if (YamlMF.Legalized)
336     MF.getProperties().set(MachineFunctionProperties::Property::Legalized);
337   if (YamlMF.RegBankSelected)
338     MF.getProperties().set(
339         MachineFunctionProperties::Property::RegBankSelected);
340   if (YamlMF.Selected)
341     MF.getProperties().set(MachineFunctionProperties::Property::Selected);
342 
343   PerFunctionMIParsingState PFS(MF, SM, IRSlots, Names2RegClasses,
344                                 Names2RegBanks);
345   if (parseRegisterInfo(PFS, YamlMF))
346     return true;
347   if (!YamlMF.Constants.empty()) {
348     auto *ConstantPool = MF.getConstantPool();
349     assert(ConstantPool && "Constant pool must be created");
350     if (initializeConstantPool(PFS, *ConstantPool, YamlMF))
351       return true;
352   }
353 
354   StringRef BlockStr = YamlMF.Body.Value.Value;
355   SMDiagnostic Error;
356   SourceMgr BlockSM;
357   BlockSM.AddNewSourceBuffer(
358       MemoryBuffer::getMemBuffer(BlockStr, "",/*RequiresNullTerminator=*/false),
359       SMLoc());
360   PFS.SM = &BlockSM;
361   if (parseMachineBasicBlockDefinitions(PFS, BlockStr, Error)) {
362     reportDiagnostic(
363         diagFromBlockStringDiag(Error, YamlMF.Body.Value.SourceRange));
364     return true;
365   }
366   PFS.SM = &SM;
367 
368   // Initialize the frame information after creating all the MBBs so that the
369   // MBB references in the frame information can be resolved.
370   if (initializeFrameInfo(PFS, YamlMF))
371     return true;
372   // Initialize the jump table after creating all the MBBs so that the MBB
373   // references can be resolved.
374   if (!YamlMF.JumpTableInfo.Entries.empty() &&
375       initializeJumpTableInfo(PFS, YamlMF.JumpTableInfo))
376     return true;
377   // Parse the machine instructions after creating all of the MBBs so that the
378   // parser can resolve the MBB references.
379   StringRef InsnStr = YamlMF.Body.Value.Value;
380   SourceMgr InsnSM;
381   InsnSM.AddNewSourceBuffer(
382       MemoryBuffer::getMemBuffer(InsnStr, "", /*RequiresNullTerminator=*/false),
383       SMLoc());
384   PFS.SM = &InsnSM;
385   if (parseMachineInstructions(PFS, InsnStr, Error)) {
386     reportDiagnostic(
387         diagFromBlockStringDiag(Error, YamlMF.Body.Value.SourceRange));
388     return true;
389   }
390   PFS.SM = &SM;
391 
392   if (setupRegisterInfo(PFS, YamlMF))
393     return true;
394 
395   computeFunctionProperties(MF);
396 
397   MF.verify();
398   return false;
399 }
400 
401 bool MIRParserImpl::parseRegisterInfo(PerFunctionMIParsingState &PFS,
402                                       const yaml::MachineFunction &YamlMF) {
403   MachineFunction &MF = PFS.MF;
404   MachineRegisterInfo &RegInfo = MF.getRegInfo();
405   assert(RegInfo.tracksLiveness());
406   if (!YamlMF.TracksRegLiveness)
407     RegInfo.invalidateLiveness();
408 
409   SMDiagnostic Error;
410   // Parse the virtual register information.
411   for (const auto &VReg : YamlMF.VirtualRegisters) {
412     VRegInfo &Info = PFS.getVRegInfo(VReg.ID.Value);
413     if (Info.Explicit)
414       return error(VReg.ID.SourceRange.Start,
415                    Twine("redefinition of virtual register '%") +
416                        Twine(VReg.ID.Value) + "'");
417     Info.Explicit = true;
418 
419     if (StringRef(VReg.Class.Value).equals("_")) {
420       Info.Kind = VRegInfo::GENERIC;
421     } else {
422       const auto *RC = getRegClass(MF, VReg.Class.Value);
423       if (RC) {
424         Info.Kind = VRegInfo::NORMAL;
425         Info.D.RC = RC;
426       } else {
427         const RegisterBank *RegBank = getRegBank(MF, VReg.Class.Value);
428         if (!RegBank)
429           return error(
430               VReg.Class.SourceRange.Start,
431               Twine("use of undefined register class or register bank '") +
432                   VReg.Class.Value + "'");
433         Info.Kind = VRegInfo::REGBANK;
434         Info.D.RegBank = RegBank;
435       }
436     }
437 
438     if (!VReg.PreferredRegister.Value.empty()) {
439       if (Info.Kind != VRegInfo::NORMAL)
440         return error(VReg.Class.SourceRange.Start,
441               Twine("preferred register can only be set for normal vregs"));
442 
443       if (parseRegisterReference(PFS, Info.PreferredReg,
444                                  VReg.PreferredRegister.Value, Error))
445         return error(Error, VReg.PreferredRegister.SourceRange);
446     }
447   }
448 
449   // Parse the liveins.
450   for (const auto &LiveIn : YamlMF.LiveIns) {
451     unsigned Reg = 0;
452     if (parseNamedRegisterReference(PFS, Reg, LiveIn.Register.Value, Error))
453       return error(Error, LiveIn.Register.SourceRange);
454     unsigned VReg = 0;
455     if (!LiveIn.VirtualRegister.Value.empty()) {
456       VRegInfo *Info;
457       if (parseVirtualRegisterReference(PFS, Info, LiveIn.VirtualRegister.Value,
458                                         Error))
459         return error(Error, LiveIn.VirtualRegister.SourceRange);
460       VReg = Info->VReg;
461     }
462     RegInfo.addLiveIn(Reg, VReg);
463   }
464 
465   // Parse the callee saved registers (Registers that will
466   // be saved for the caller).
467   if (YamlMF.CalleeSavedRegisters) {
468     SmallVector<MCPhysReg, 16> CalleeSavedRegisters;
469     for (const auto &RegSource : YamlMF.CalleeSavedRegisters.getValue()) {
470       unsigned Reg = 0;
471       if (parseNamedRegisterReference(PFS, Reg, RegSource.Value, Error))
472         return error(Error, RegSource.SourceRange);
473       CalleeSavedRegisters.push_back(Reg);
474     }
475     RegInfo.setCalleeSavedRegs(CalleeSavedRegisters);
476   }
477 
478   return false;
479 }
480 
481 bool MIRParserImpl::setupRegisterInfo(const PerFunctionMIParsingState &PFS,
482                                       const yaml::MachineFunction &YamlMF) {
483   MachineFunction &MF = PFS.MF;
484   MachineRegisterInfo &MRI = MF.getRegInfo();
485   bool Error = false;
486   // Create VRegs
487   for (auto P : PFS.VRegInfos) {
488     const VRegInfo &Info = *P.second;
489     unsigned Reg = Info.VReg;
490     switch (Info.Kind) {
491     case VRegInfo::UNKNOWN:
492       error(Twine("Cannot determine class/bank of virtual register ") +
493             Twine(P.first) + " in function '" + MF.getName() + "'");
494       Error = true;
495       break;
496     case VRegInfo::NORMAL:
497       MRI.setRegClass(Reg, Info.D.RC);
498       if (Info.PreferredReg != 0)
499         MRI.setSimpleHint(Reg, Info.PreferredReg);
500       break;
501     case VRegInfo::GENERIC:
502       break;
503     case VRegInfo::REGBANK:
504       MRI.setRegBank(Reg, *Info.D.RegBank);
505       break;
506     }
507   }
508 
509   // Compute MachineRegisterInfo::UsedPhysRegMask
510   for (const MachineBasicBlock &MBB : MF) {
511     for (const MachineInstr &MI : MBB) {
512       for (const MachineOperand &MO : MI.operands()) {
513         if (!MO.isRegMask())
514           continue;
515         MRI.addPhysRegsUsedFromRegMask(MO.getRegMask());
516       }
517     }
518   }
519 
520   // FIXME: This is a temporary workaround until the reserved registers can be
521   // serialized.
522   MRI.freezeReservedRegs(MF);
523   return Error;
524 }
525 
526 bool MIRParserImpl::initializeFrameInfo(PerFunctionMIParsingState &PFS,
527                                         const yaml::MachineFunction &YamlMF) {
528   MachineFunction &MF = PFS.MF;
529   MachineFrameInfo &MFI = MF.getFrameInfo();
530   const Function &F = *MF.getFunction();
531   const yaml::MachineFrameInfo &YamlMFI = YamlMF.FrameInfo;
532   MFI.setFrameAddressIsTaken(YamlMFI.IsFrameAddressTaken);
533   MFI.setReturnAddressIsTaken(YamlMFI.IsReturnAddressTaken);
534   MFI.setHasStackMap(YamlMFI.HasStackMap);
535   MFI.setHasPatchPoint(YamlMFI.HasPatchPoint);
536   MFI.setStackSize(YamlMFI.StackSize);
537   MFI.setOffsetAdjustment(YamlMFI.OffsetAdjustment);
538   if (YamlMFI.MaxAlignment)
539     MFI.ensureMaxAlignment(YamlMFI.MaxAlignment);
540   MFI.setAdjustsStack(YamlMFI.AdjustsStack);
541   MFI.setHasCalls(YamlMFI.HasCalls);
542   if (YamlMFI.MaxCallFrameSize != ~0u)
543     MFI.setMaxCallFrameSize(YamlMFI.MaxCallFrameSize);
544   MFI.setHasOpaqueSPAdjustment(YamlMFI.HasOpaqueSPAdjustment);
545   MFI.setHasVAStart(YamlMFI.HasVAStart);
546   MFI.setHasMustTailInVarArgFunc(YamlMFI.HasMustTailInVarArgFunc);
547   if (!YamlMFI.SavePoint.Value.empty()) {
548     MachineBasicBlock *MBB = nullptr;
549     if (parseMBBReference(PFS, MBB, YamlMFI.SavePoint))
550       return true;
551     MFI.setSavePoint(MBB);
552   }
553   if (!YamlMFI.RestorePoint.Value.empty()) {
554     MachineBasicBlock *MBB = nullptr;
555     if (parseMBBReference(PFS, MBB, YamlMFI.RestorePoint))
556       return true;
557     MFI.setRestorePoint(MBB);
558   }
559 
560   std::vector<CalleeSavedInfo> CSIInfo;
561   // Initialize the fixed frame objects.
562   for (const auto &Object : YamlMF.FixedStackObjects) {
563     int ObjectIdx;
564     if (Object.Type != yaml::FixedMachineStackObject::SpillSlot)
565       ObjectIdx = MFI.CreateFixedObject(Object.Size, Object.Offset,
566                                         Object.IsImmutable, Object.IsAliased);
567     else
568       ObjectIdx = MFI.CreateFixedSpillStackObject(Object.Size, Object.Offset);
569     MFI.setObjectAlignment(ObjectIdx, Object.Alignment);
570     if (!PFS.FixedStackObjectSlots.insert(std::make_pair(Object.ID.Value,
571                                                          ObjectIdx))
572              .second)
573       return error(Object.ID.SourceRange.Start,
574                    Twine("redefinition of fixed stack object '%fixed-stack.") +
575                        Twine(Object.ID.Value) + "'");
576     if (parseCalleeSavedRegister(PFS, CSIInfo, Object.CalleeSavedRegister,
577                                  ObjectIdx))
578       return true;
579   }
580 
581   // Initialize the ordinary frame objects.
582   for (const auto &Object : YamlMF.StackObjects) {
583     int ObjectIdx;
584     const AllocaInst *Alloca = nullptr;
585     const yaml::StringValue &Name = Object.Name;
586     if (!Name.Value.empty()) {
587       Alloca = dyn_cast_or_null<AllocaInst>(
588           F.getValueSymbolTable()->lookup(Name.Value));
589       if (!Alloca)
590         return error(Name.SourceRange.Start,
591                      "alloca instruction named '" + Name.Value +
592                          "' isn't defined in the function '" + F.getName() +
593                          "'");
594     }
595     if (Object.Type == yaml::MachineStackObject::VariableSized)
596       ObjectIdx = MFI.CreateVariableSizedObject(Object.Alignment, Alloca);
597     else
598       ObjectIdx = MFI.CreateStackObject(
599           Object.Size, Object.Alignment,
600           Object.Type == yaml::MachineStackObject::SpillSlot, Alloca);
601     MFI.setObjectOffset(ObjectIdx, Object.Offset);
602     if (!PFS.StackObjectSlots.insert(std::make_pair(Object.ID.Value, ObjectIdx))
603              .second)
604       return error(Object.ID.SourceRange.Start,
605                    Twine("redefinition of stack object '%stack.") +
606                        Twine(Object.ID.Value) + "'");
607     if (parseCalleeSavedRegister(PFS, CSIInfo, Object.CalleeSavedRegister,
608                                  ObjectIdx))
609       return true;
610     if (Object.LocalOffset)
611       MFI.mapLocalFrameObject(ObjectIdx, Object.LocalOffset.getValue());
612     if (parseStackObjectsDebugInfo(PFS, Object, ObjectIdx))
613       return true;
614   }
615   MFI.setCalleeSavedInfo(CSIInfo);
616   if (!CSIInfo.empty())
617     MFI.setCalleeSavedInfoValid(true);
618 
619   // Initialize the various stack object references after initializing the
620   // stack objects.
621   if (!YamlMFI.StackProtector.Value.empty()) {
622     SMDiagnostic Error;
623     int FI;
624     if (parseStackObjectReference(PFS, FI, YamlMFI.StackProtector.Value, Error))
625       return error(Error, YamlMFI.StackProtector.SourceRange);
626     MFI.setStackProtectorIndex(FI);
627   }
628   return false;
629 }
630 
631 bool MIRParserImpl::parseCalleeSavedRegister(PerFunctionMIParsingState &PFS,
632     std::vector<CalleeSavedInfo> &CSIInfo,
633     const yaml::StringValue &RegisterSource, int FrameIdx) {
634   if (RegisterSource.Value.empty())
635     return false;
636   unsigned Reg = 0;
637   SMDiagnostic Error;
638   if (parseNamedRegisterReference(PFS, Reg, RegisterSource.Value, Error))
639     return error(Error, RegisterSource.SourceRange);
640   CSIInfo.push_back(CalleeSavedInfo(Reg, FrameIdx));
641   return false;
642 }
643 
644 /// Verify that given node is of a certain type. Return true on error.
645 template <typename T>
646 static bool typecheckMDNode(T *&Result, MDNode *Node,
647                             const yaml::StringValue &Source,
648                             StringRef TypeString, MIRParserImpl &Parser) {
649   if (!Node)
650     return false;
651   Result = dyn_cast<T>(Node);
652   if (!Result)
653     return Parser.error(Source.SourceRange.Start,
654                         "expected a reference to a '" + TypeString +
655                             "' metadata node");
656   return false;
657 }
658 
659 bool MIRParserImpl::parseStackObjectsDebugInfo(PerFunctionMIParsingState &PFS,
660     const yaml::MachineStackObject &Object, int FrameIdx) {
661   // Debug information can only be attached to stack objects; Fixed stack
662   // objects aren't supported.
663   assert(FrameIdx >= 0 && "Expected a stack object frame index");
664   MDNode *Var = nullptr, *Expr = nullptr, *Loc = nullptr;
665   if (parseMDNode(PFS, Var, Object.DebugVar) ||
666       parseMDNode(PFS, Expr, Object.DebugExpr) ||
667       parseMDNode(PFS, Loc, Object.DebugLoc))
668     return true;
669   if (!Var && !Expr && !Loc)
670     return false;
671   DILocalVariable *DIVar = nullptr;
672   DIExpression *DIExpr = nullptr;
673   DILocation *DILoc = nullptr;
674   if (typecheckMDNode(DIVar, Var, Object.DebugVar, "DILocalVariable", *this) ||
675       typecheckMDNode(DIExpr, Expr, Object.DebugExpr, "DIExpression", *this) ||
676       typecheckMDNode(DILoc, Loc, Object.DebugLoc, "DILocation", *this))
677     return true;
678   PFS.MF.setVariableDbgInfo(DIVar, DIExpr, unsigned(FrameIdx), DILoc);
679   return false;
680 }
681 
682 bool MIRParserImpl::parseMDNode(PerFunctionMIParsingState &PFS,
683     MDNode *&Node, const yaml::StringValue &Source) {
684   if (Source.Value.empty())
685     return false;
686   SMDiagnostic Error;
687   if (llvm::parseMDNode(PFS, Node, Source.Value, Error))
688     return error(Error, Source.SourceRange);
689   return false;
690 }
691 
692 bool MIRParserImpl::initializeConstantPool(PerFunctionMIParsingState &PFS,
693     MachineConstantPool &ConstantPool, const yaml::MachineFunction &YamlMF) {
694   DenseMap<unsigned, unsigned> &ConstantPoolSlots = PFS.ConstantPoolSlots;
695   const MachineFunction &MF = PFS.MF;
696   const auto &M = *MF.getFunction()->getParent();
697   SMDiagnostic Error;
698   for (const auto &YamlConstant : YamlMF.Constants) {
699     const Constant *Value = dyn_cast_or_null<Constant>(
700         parseConstantValue(YamlConstant.Value.Value, Error, M));
701     if (!Value)
702       return error(Error, YamlConstant.Value.SourceRange);
703     unsigned Alignment =
704         YamlConstant.Alignment
705             ? YamlConstant.Alignment
706             : M.getDataLayout().getPrefTypeAlignment(Value->getType());
707     unsigned Index = ConstantPool.getConstantPoolIndex(Value, Alignment);
708     if (!ConstantPoolSlots.insert(std::make_pair(YamlConstant.ID.Value, Index))
709              .second)
710       return error(YamlConstant.ID.SourceRange.Start,
711                    Twine("redefinition of constant pool item '%const.") +
712                        Twine(YamlConstant.ID.Value) + "'");
713   }
714   return false;
715 }
716 
717 bool MIRParserImpl::initializeJumpTableInfo(PerFunctionMIParsingState &PFS,
718     const yaml::MachineJumpTable &YamlJTI) {
719   MachineJumpTableInfo *JTI = PFS.MF.getOrCreateJumpTableInfo(YamlJTI.Kind);
720   for (const auto &Entry : YamlJTI.Entries) {
721     std::vector<MachineBasicBlock *> Blocks;
722     for (const auto &MBBSource : Entry.Blocks) {
723       MachineBasicBlock *MBB = nullptr;
724       if (parseMBBReference(PFS, MBB, MBBSource.Value))
725         return true;
726       Blocks.push_back(MBB);
727     }
728     unsigned Index = JTI->createJumpTableIndex(Blocks);
729     if (!PFS.JumpTableSlots.insert(std::make_pair(Entry.ID.Value, Index))
730              .second)
731       return error(Entry.ID.SourceRange.Start,
732                    Twine("redefinition of jump table entry '%jump-table.") +
733                        Twine(Entry.ID.Value) + "'");
734   }
735   return false;
736 }
737 
738 bool MIRParserImpl::parseMBBReference(PerFunctionMIParsingState &PFS,
739                                       MachineBasicBlock *&MBB,
740                                       const yaml::StringValue &Source) {
741   SMDiagnostic Error;
742   if (llvm::parseMBBReference(PFS, MBB, Source.Value, Error))
743     return error(Error, Source.SourceRange);
744   return false;
745 }
746 
747 SMDiagnostic MIRParserImpl::diagFromMIStringDiag(const SMDiagnostic &Error,
748                                                  SMRange SourceRange) {
749   assert(SourceRange.isValid() && "Invalid source range");
750   SMLoc Loc = SourceRange.Start;
751   bool HasQuote = Loc.getPointer() < SourceRange.End.getPointer() &&
752                   *Loc.getPointer() == '\'';
753   // Translate the location of the error from the location in the MI string to
754   // the corresponding location in the MIR file.
755   Loc = Loc.getFromPointer(Loc.getPointer() + Error.getColumnNo() +
756                            (HasQuote ? 1 : 0));
757 
758   // TODO: Translate any source ranges as well.
759   return SM.GetMessage(Loc, Error.getKind(), Error.getMessage(), None,
760                        Error.getFixIts());
761 }
762 
763 SMDiagnostic MIRParserImpl::diagFromBlockStringDiag(const SMDiagnostic &Error,
764                                                     SMRange SourceRange) {
765   assert(SourceRange.isValid());
766 
767   // Translate the location of the error from the location in the llvm IR string
768   // to the corresponding location in the MIR file.
769   auto LineAndColumn = SM.getLineAndColumn(SourceRange.Start);
770   unsigned Line = LineAndColumn.first + Error.getLineNo() - 1;
771   unsigned Column = Error.getColumnNo();
772   StringRef LineStr = Error.getLineContents();
773   SMLoc Loc = Error.getLoc();
774 
775   // Get the full line and adjust the column number by taking the indentation of
776   // LLVM IR into account.
777   for (line_iterator L(*SM.getMemoryBuffer(SM.getMainFileID()), false), E;
778        L != E; ++L) {
779     if (L.line_number() == Line) {
780       LineStr = *L;
781       Loc = SMLoc::getFromPointer(LineStr.data());
782       auto Indent = LineStr.find(Error.getLineContents());
783       if (Indent != StringRef::npos)
784         Column += Indent;
785       break;
786     }
787   }
788 
789   return SMDiagnostic(SM, Loc, Filename, Line, Column, Error.getKind(),
790                       Error.getMessage(), LineStr, Error.getRanges(),
791                       Error.getFixIts());
792 }
793 
794 void MIRParserImpl::initNames2RegClasses(const MachineFunction &MF) {
795   if (!Names2RegClasses.empty())
796     return;
797   const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
798   for (unsigned I = 0, E = TRI->getNumRegClasses(); I < E; ++I) {
799     const auto *RC = TRI->getRegClass(I);
800     Names2RegClasses.insert(
801         std::make_pair(StringRef(TRI->getRegClassName(RC)).lower(), RC));
802   }
803 }
804 
805 void MIRParserImpl::initNames2RegBanks(const MachineFunction &MF) {
806   if (!Names2RegBanks.empty())
807     return;
808   const RegisterBankInfo *RBI = MF.getSubtarget().getRegBankInfo();
809   // If the target does not support GlobalISel, we may not have a
810   // register bank info.
811   if (!RBI)
812     return;
813   for (unsigned I = 0, E = RBI->getNumRegBanks(); I < E; ++I) {
814     const auto &RegBank = RBI->getRegBank(I);
815     Names2RegBanks.insert(
816         std::make_pair(StringRef(RegBank.getName()).lower(), &RegBank));
817   }
818 }
819 
820 const TargetRegisterClass *MIRParserImpl::getRegClass(const MachineFunction &MF,
821                                                       StringRef Name) {
822   auto RegClassInfo = Names2RegClasses.find(Name);
823   if (RegClassInfo == Names2RegClasses.end())
824     return nullptr;
825   return RegClassInfo->getValue();
826 }
827 
828 const RegisterBank *MIRParserImpl::getRegBank(const MachineFunction &MF,
829                                               StringRef Name) {
830   auto RegBankInfo = Names2RegBanks.find(Name);
831   if (RegBankInfo == Names2RegBanks.end())
832     return nullptr;
833   return RegBankInfo->getValue();
834 }
835 
836 MIRParser::MIRParser(std::unique_ptr<MIRParserImpl> Impl)
837     : Impl(std::move(Impl)) {}
838 
839 MIRParser::~MIRParser() {}
840 
841 std::unique_ptr<Module> MIRParser::parseLLVMModule() { return Impl->parse(); }
842 
843 bool MIRParser::initializeMachineFunction(MachineFunction &MF) {
844   return Impl->initializeMachineFunction(MF);
845 }
846 
847 std::unique_ptr<MIRParser> llvm::createMIRParserFromFile(StringRef Filename,
848                                                          SMDiagnostic &Error,
849                                                          LLVMContext &Context) {
850   auto FileOrErr = MemoryBuffer::getFile(Filename);
851   if (std::error_code EC = FileOrErr.getError()) {
852     Error = SMDiagnostic(Filename, SourceMgr::DK_Error,
853                          "Could not open input file: " + EC.message());
854     return nullptr;
855   }
856   return createMIRParser(std::move(FileOrErr.get()), Context);
857 }
858 
859 std::unique_ptr<MIRParser>
860 llvm::createMIRParser(std::unique_ptr<MemoryBuffer> Contents,
861                       LLVMContext &Context) {
862   auto Filename = Contents->getBufferIdentifier();
863   if (Context.shouldDiscardValueNames()) {
864     Context.diagnose(DiagnosticInfoMIRParser(
865         DS_Error,
866         SMDiagnostic(
867             Filename, SourceMgr::DK_Error,
868             "Can't read MIR with a Context that discards named Values")));
869     return nullptr;
870   }
871   return llvm::make_unique<MIRParser>(
872       llvm::make_unique<MIRParserImpl>(std::move(Contents), Filename, Context));
873 }
874