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   yaml::Input In;
54   StringRef Filename;
55   LLVMContext &Context;
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   /// True when the MIR file doesn't have LLVM IR. Dummy IR functions are
62   /// created and inserted into the given module when this is true.
63   bool NoLLVMIR = false;
64   /// True when a well formed MIR file does not contain any MIR/machine function
65   /// parts.
66   bool NoMIRDocuments = false;
67 
68 public:
69   MIRParserImpl(std::unique_ptr<MemoryBuffer> Contents,
70                 StringRef Filename, LLVMContext &Context);
71 
72   void reportDiagnostic(const SMDiagnostic &Diag);
73 
74   /// Report an error with the given message at unknown location.
75   ///
76   /// Always returns true.
77   bool error(const Twine &Message);
78 
79   /// Report an error with the given message at the given location.
80   ///
81   /// Always returns true.
82   bool error(SMLoc Loc, const Twine &Message);
83 
84   /// Report a given error with the location translated from the location in an
85   /// embedded string literal to a location in the MIR file.
86   ///
87   /// Always returns true.
88   bool error(const SMDiagnostic &Error, SMRange SourceRange);
89 
90   /// Try to parse the optional LLVM module and the machine functions in the MIR
91   /// file.
92   ///
93   /// Return null if an error occurred.
94   std::unique_ptr<Module> parseIRModule();
95 
96   bool parseMachineFunctions(Module &M, MachineModuleInfo &MMI);
97 
98   /// Parse the machine function in the current YAML document.
99   ///
100   ///
101   /// Return true if an error occurred.
102   bool parseMachineFunction(Module &M, MachineModuleInfo &MMI);
103 
104   /// Initialize the machine function to the state that's described in the MIR
105   /// file.
106   ///
107   /// Return true if error occurred.
108   bool initializeMachineFunction(const yaml::MachineFunction &YamlMF,
109                                  MachineFunction &MF);
110 
111   bool parseRegisterInfo(PerFunctionMIParsingState &PFS,
112                          const yaml::MachineFunction &YamlMF);
113 
114   bool setupRegisterInfo(const PerFunctionMIParsingState &PFS,
115                          const yaml::MachineFunction &YamlMF);
116 
117   bool initializeFrameInfo(PerFunctionMIParsingState &PFS,
118                            const yaml::MachineFunction &YamlMF);
119 
120   bool parseCalleeSavedRegister(PerFunctionMIParsingState &PFS,
121                                 std::vector<CalleeSavedInfo> &CSIInfo,
122                                 const yaml::StringValue &RegisterSource,
123                                 int FrameIdx);
124 
125   bool parseStackObjectsDebugInfo(PerFunctionMIParsingState &PFS,
126                                   const yaml::MachineStackObject &Object,
127                                   int FrameIdx);
128 
129   bool initializeConstantPool(PerFunctionMIParsingState &PFS,
130                               MachineConstantPool &ConstantPool,
131                               const yaml::MachineFunction &YamlMF);
132 
133   bool initializeJumpTableInfo(PerFunctionMIParsingState &PFS,
134                                const yaml::MachineJumpTable &YamlJTI);
135 
136 private:
137   bool parseMDNode(PerFunctionMIParsingState &PFS, MDNode *&Node,
138                    const yaml::StringValue &Source);
139 
140   bool parseMBBReference(PerFunctionMIParsingState &PFS,
141                          MachineBasicBlock *&MBB,
142                          const yaml::StringValue &Source);
143 
144   /// Return a MIR diagnostic converted from an MI string diagnostic.
145   SMDiagnostic diagFromMIStringDiag(const SMDiagnostic &Error,
146                                     SMRange SourceRange);
147 
148   /// Return a MIR diagnostic converted from a diagnostic located in a YAML
149   /// block scalar string.
150   SMDiagnostic diagFromBlockStringDiag(const SMDiagnostic &Error,
151                                        SMRange SourceRange);
152 
153   void initNames2RegClasses(const MachineFunction &MF);
154   void initNames2RegBanks(const MachineFunction &MF);
155 
156   /// Check if the given identifier is a name of a register class.
157   ///
158   /// Return null if the name isn't a register class.
159   const TargetRegisterClass *getRegClass(const MachineFunction &MF,
160                                          StringRef Name);
161 
162   /// Check if the given identifier is a name of a register bank.
163   ///
164   /// Return null if the name isn't a register bank.
165   const RegisterBank *getRegBank(const MachineFunction &MF, StringRef Name);
166 
167   void computeFunctionProperties(MachineFunction &MF);
168 };
169 
170 } // end namespace llvm
171 
172 static void handleYAMLDiag(const SMDiagnostic &Diag, void *Context) {
173   reinterpret_cast<MIRParserImpl *>(Context)->reportDiagnostic(Diag);
174 }
175 
176 MIRParserImpl::MIRParserImpl(std::unique_ptr<MemoryBuffer> Contents,
177                              StringRef Filename, LLVMContext &Context)
178     : SM(),
179       In(SM.getMemoryBuffer(
180             SM.AddNewSourceBuffer(std::move(Contents), SMLoc()))->getBuffer(),
181             nullptr, handleYAMLDiag, this),
182       Filename(Filename),
183       Context(Context) {
184   In.setContext(&In);
185 }
186 
187 bool MIRParserImpl::error(const Twine &Message) {
188   Context.diagnose(DiagnosticInfoMIRParser(
189       DS_Error, SMDiagnostic(Filename, SourceMgr::DK_Error, Message.str())));
190   return true;
191 }
192 
193 bool MIRParserImpl::error(SMLoc Loc, const Twine &Message) {
194   Context.diagnose(DiagnosticInfoMIRParser(
195       DS_Error, SM.GetMessage(Loc, SourceMgr::DK_Error, Message)));
196   return true;
197 }
198 
199 bool MIRParserImpl::error(const SMDiagnostic &Error, SMRange SourceRange) {
200   assert(Error.getKind() == SourceMgr::DK_Error && "Expected an error");
201   reportDiagnostic(diagFromMIStringDiag(Error, SourceRange));
202   return true;
203 }
204 
205 void MIRParserImpl::reportDiagnostic(const SMDiagnostic &Diag) {
206   DiagnosticSeverity Kind;
207   switch (Diag.getKind()) {
208   case SourceMgr::DK_Error:
209     Kind = DS_Error;
210     break;
211   case SourceMgr::DK_Warning:
212     Kind = DS_Warning;
213     break;
214   case SourceMgr::DK_Note:
215     Kind = DS_Note;
216     break;
217   }
218   Context.diagnose(DiagnosticInfoMIRParser(Kind, Diag));
219 }
220 
221 std::unique_ptr<Module> MIRParserImpl::parseIRModule() {
222   if (!In.setCurrentDocument()) {
223     if (In.error())
224       return nullptr;
225     // Create an empty module when the MIR file is empty.
226     NoMIRDocuments = true;
227     return llvm::make_unique<Module>(Filename, Context);
228   }
229 
230   std::unique_ptr<Module> M;
231   // Parse the block scalar manually so that we can return unique pointer
232   // without having to go trough YAML traits.
233   if (const auto *BSN =
234           dyn_cast_or_null<yaml::BlockScalarNode>(In.getCurrentNode())) {
235     SMDiagnostic Error;
236     M = parseAssembly(MemoryBufferRef(BSN->getValue(), Filename), Error,
237                       Context, &IRSlots);
238     if (!M) {
239       reportDiagnostic(diagFromBlockStringDiag(Error, BSN->getSourceRange()));
240       return nullptr;
241     }
242     In.nextDocument();
243     if (!In.setCurrentDocument())
244       NoMIRDocuments = true;
245   } else {
246     // Create an new, empty module.
247     M = llvm::make_unique<Module>(Filename, Context);
248     NoLLVMIR = true;
249   }
250   return M;
251 }
252 
253 bool MIRParserImpl::parseMachineFunctions(Module &M, MachineModuleInfo &MMI) {
254   if (NoMIRDocuments)
255     return false;
256 
257   // Parse the machine functions.
258   do {
259     if (parseMachineFunction(M, MMI))
260       return true;
261     In.nextDocument();
262   } while (In.setCurrentDocument());
263 
264   return false;
265 }
266 
267 /// Create an empty function with the given name.
268 static Function *createDummyFunction(StringRef Name, Module &M) {
269   auto &Context = M.getContext();
270   Function *F = cast<Function>(M.getOrInsertFunction(
271       Name, FunctionType::get(Type::getVoidTy(Context), false)));
272   BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
273   new UnreachableInst(Context, BB);
274   return F;
275 }
276 
277 bool MIRParserImpl::parseMachineFunction(Module &M, MachineModuleInfo &MMI) {
278   // Parse the yaml.
279   yaml::MachineFunction YamlMF;
280   yaml::EmptyContext Ctx;
281   yaml::yamlize(In, YamlMF, false, Ctx);
282   if (In.error())
283     return true;
284 
285   // Search for the corresponding IR function.
286   StringRef FunctionName = YamlMF.Name;
287   Function *F = M.getFunction(FunctionName);
288   if (!F) {
289     if (NoLLVMIR) {
290       F = createDummyFunction(FunctionName, M);
291     } else {
292       return error(Twine("function '") + FunctionName +
293                    "' isn't defined in the provided LLVM IR");
294     }
295   }
296   if (MMI.getMachineFunction(*F) != nullptr)
297     return error(Twine("redefinition of machine function '") + FunctionName +
298                  "'");
299 
300   // Create the MachineFunction.
301   MachineFunction &MF = MMI.getOrCreateMachineFunction(*F);
302   if (initializeMachineFunction(YamlMF, MF))
303     return true;
304 
305   return false;
306 }
307 
308 static bool isSSA(const MachineFunction &MF) {
309   const MachineRegisterInfo &MRI = MF.getRegInfo();
310   for (unsigned I = 0, E = MRI.getNumVirtRegs(); I != E; ++I) {
311     unsigned Reg = TargetRegisterInfo::index2VirtReg(I);
312     if (!MRI.hasOneDef(Reg) && !MRI.def_empty(Reg))
313       return false;
314   }
315   return true;
316 }
317 
318 void MIRParserImpl::computeFunctionProperties(MachineFunction &MF) {
319   MachineFunctionProperties &Properties = MF.getProperties();
320 
321   bool HasPHI = false;
322   bool HasInlineAsm = false;
323   for (const MachineBasicBlock &MBB : MF) {
324     for (const MachineInstr &MI : MBB) {
325       if (MI.isPHI())
326         HasPHI = true;
327       if (MI.isInlineAsm())
328         HasInlineAsm = true;
329     }
330   }
331   if (!HasPHI)
332     Properties.set(MachineFunctionProperties::Property::NoPHIs);
333   MF.setHasInlineAsm(HasInlineAsm);
334 
335   if (isSSA(MF))
336     Properties.set(MachineFunctionProperties::Property::IsSSA);
337   else
338     Properties.reset(MachineFunctionProperties::Property::IsSSA);
339 
340   const MachineRegisterInfo &MRI = MF.getRegInfo();
341   if (MRI.getNumVirtRegs() == 0)
342     Properties.set(MachineFunctionProperties::Property::NoVRegs);
343 }
344 
345 bool
346 MIRParserImpl::initializeMachineFunction(const yaml::MachineFunction &YamlMF,
347                                          MachineFunction &MF) {
348   // TODO: Recreate the machine function.
349   initNames2RegClasses(MF);
350   initNames2RegBanks(MF);
351   if (YamlMF.Alignment)
352     MF.setAlignment(YamlMF.Alignment);
353   MF.setExposesReturnsTwice(YamlMF.ExposesReturnsTwice);
354 
355   if (YamlMF.Legalized)
356     MF.getProperties().set(MachineFunctionProperties::Property::Legalized);
357   if (YamlMF.RegBankSelected)
358     MF.getProperties().set(
359         MachineFunctionProperties::Property::RegBankSelected);
360   if (YamlMF.Selected)
361     MF.getProperties().set(MachineFunctionProperties::Property::Selected);
362 
363   PerFunctionMIParsingState PFS(MF, SM, IRSlots, Names2RegClasses,
364                                 Names2RegBanks);
365   if (parseRegisterInfo(PFS, YamlMF))
366     return true;
367   if (!YamlMF.Constants.empty()) {
368     auto *ConstantPool = MF.getConstantPool();
369     assert(ConstantPool && "Constant pool must be created");
370     if (initializeConstantPool(PFS, *ConstantPool, YamlMF))
371       return true;
372   }
373 
374   StringRef BlockStr = YamlMF.Body.Value.Value;
375   SMDiagnostic Error;
376   SourceMgr BlockSM;
377   BlockSM.AddNewSourceBuffer(
378       MemoryBuffer::getMemBuffer(BlockStr, "",/*RequiresNullTerminator=*/false),
379       SMLoc());
380   PFS.SM = &BlockSM;
381   if (parseMachineBasicBlockDefinitions(PFS, BlockStr, Error)) {
382     reportDiagnostic(
383         diagFromBlockStringDiag(Error, YamlMF.Body.Value.SourceRange));
384     return true;
385   }
386   PFS.SM = &SM;
387 
388   // Initialize the frame information after creating all the MBBs so that the
389   // MBB references in the frame information can be resolved.
390   if (initializeFrameInfo(PFS, YamlMF))
391     return true;
392   // Initialize the jump table after creating all the MBBs so that the MBB
393   // references can be resolved.
394   if (!YamlMF.JumpTableInfo.Entries.empty() &&
395       initializeJumpTableInfo(PFS, YamlMF.JumpTableInfo))
396     return true;
397   // Parse the machine instructions after creating all of the MBBs so that the
398   // parser can resolve the MBB references.
399   StringRef InsnStr = YamlMF.Body.Value.Value;
400   SourceMgr InsnSM;
401   InsnSM.AddNewSourceBuffer(
402       MemoryBuffer::getMemBuffer(InsnStr, "", /*RequiresNullTerminator=*/false),
403       SMLoc());
404   PFS.SM = &InsnSM;
405   if (parseMachineInstructions(PFS, InsnStr, Error)) {
406     reportDiagnostic(
407         diagFromBlockStringDiag(Error, YamlMF.Body.Value.SourceRange));
408     return true;
409   }
410   PFS.SM = &SM;
411 
412   if (setupRegisterInfo(PFS, YamlMF))
413     return true;
414 
415   computeFunctionProperties(MF);
416 
417   MF.verify();
418   return false;
419 }
420 
421 bool MIRParserImpl::parseRegisterInfo(PerFunctionMIParsingState &PFS,
422                                       const yaml::MachineFunction &YamlMF) {
423   MachineFunction &MF = PFS.MF;
424   MachineRegisterInfo &RegInfo = MF.getRegInfo();
425   assert(RegInfo.tracksLiveness());
426   if (!YamlMF.TracksRegLiveness)
427     RegInfo.invalidateLiveness();
428 
429   SMDiagnostic Error;
430   // Parse the virtual register information.
431   for (const auto &VReg : YamlMF.VirtualRegisters) {
432     VRegInfo &Info = PFS.getVRegInfo(VReg.ID.Value);
433     if (Info.Explicit)
434       return error(VReg.ID.SourceRange.Start,
435                    Twine("redefinition of virtual register '%") +
436                        Twine(VReg.ID.Value) + "'");
437     Info.Explicit = true;
438 
439     if (StringRef(VReg.Class.Value).equals("_")) {
440       Info.Kind = VRegInfo::GENERIC;
441     } else {
442       const auto *RC = getRegClass(MF, VReg.Class.Value);
443       if (RC) {
444         Info.Kind = VRegInfo::NORMAL;
445         Info.D.RC = RC;
446       } else {
447         const RegisterBank *RegBank = getRegBank(MF, VReg.Class.Value);
448         if (!RegBank)
449           return error(
450               VReg.Class.SourceRange.Start,
451               Twine("use of undefined register class or register bank '") +
452                   VReg.Class.Value + "'");
453         Info.Kind = VRegInfo::REGBANK;
454         Info.D.RegBank = RegBank;
455       }
456     }
457 
458     if (!VReg.PreferredRegister.Value.empty()) {
459       if (Info.Kind != VRegInfo::NORMAL)
460         return error(VReg.Class.SourceRange.Start,
461               Twine("preferred register can only be set for normal vregs"));
462 
463       if (parseRegisterReference(PFS, Info.PreferredReg,
464                                  VReg.PreferredRegister.Value, Error))
465         return error(Error, VReg.PreferredRegister.SourceRange);
466     }
467   }
468 
469   // Parse the liveins.
470   for (const auto &LiveIn : YamlMF.LiveIns) {
471     unsigned Reg = 0;
472     if (parseNamedRegisterReference(PFS, Reg, LiveIn.Register.Value, Error))
473       return error(Error, LiveIn.Register.SourceRange);
474     unsigned VReg = 0;
475     if (!LiveIn.VirtualRegister.Value.empty()) {
476       VRegInfo *Info;
477       if (parseVirtualRegisterReference(PFS, Info, LiveIn.VirtualRegister.Value,
478                                         Error))
479         return error(Error, LiveIn.VirtualRegister.SourceRange);
480       VReg = Info->VReg;
481     }
482     RegInfo.addLiveIn(Reg, VReg);
483   }
484 
485   // Parse the callee saved registers (Registers that will
486   // be saved for the caller).
487   if (YamlMF.CalleeSavedRegisters) {
488     SmallVector<MCPhysReg, 16> CalleeSavedRegisters;
489     for (const auto &RegSource : YamlMF.CalleeSavedRegisters.getValue()) {
490       unsigned Reg = 0;
491       if (parseNamedRegisterReference(PFS, Reg, RegSource.Value, Error))
492         return error(Error, RegSource.SourceRange);
493       CalleeSavedRegisters.push_back(Reg);
494     }
495     RegInfo.setCalleeSavedRegs(CalleeSavedRegisters);
496   }
497 
498   return false;
499 }
500 
501 bool MIRParserImpl::setupRegisterInfo(const PerFunctionMIParsingState &PFS,
502                                       const yaml::MachineFunction &YamlMF) {
503   MachineFunction &MF = PFS.MF;
504   MachineRegisterInfo &MRI = MF.getRegInfo();
505   bool Error = false;
506   // Create VRegs
507   for (auto P : PFS.VRegInfos) {
508     const VRegInfo &Info = *P.second;
509     unsigned Reg = Info.VReg;
510     switch (Info.Kind) {
511     case VRegInfo::UNKNOWN:
512       error(Twine("Cannot determine class/bank of virtual register ") +
513             Twine(P.first) + " in function '" + MF.getName() + "'");
514       Error = true;
515       break;
516     case VRegInfo::NORMAL:
517       MRI.setRegClass(Reg, Info.D.RC);
518       if (Info.PreferredReg != 0)
519         MRI.setSimpleHint(Reg, Info.PreferredReg);
520       break;
521     case VRegInfo::GENERIC:
522       break;
523     case VRegInfo::REGBANK:
524       MRI.setRegBank(Reg, *Info.D.RegBank);
525       break;
526     }
527   }
528 
529   // Compute MachineRegisterInfo::UsedPhysRegMask
530   for (const MachineBasicBlock &MBB : MF) {
531     for (const MachineInstr &MI : MBB) {
532       for (const MachineOperand &MO : MI.operands()) {
533         if (!MO.isRegMask())
534           continue;
535         MRI.addPhysRegsUsedFromRegMask(MO.getRegMask());
536       }
537     }
538   }
539 
540   // FIXME: This is a temporary workaround until the reserved registers can be
541   // serialized.
542   MRI.freezeReservedRegs(MF);
543   return Error;
544 }
545 
546 bool MIRParserImpl::initializeFrameInfo(PerFunctionMIParsingState &PFS,
547                                         const yaml::MachineFunction &YamlMF) {
548   MachineFunction &MF = PFS.MF;
549   MachineFrameInfo &MFI = MF.getFrameInfo();
550   const Function &F = *MF.getFunction();
551   const yaml::MachineFrameInfo &YamlMFI = YamlMF.FrameInfo;
552   MFI.setFrameAddressIsTaken(YamlMFI.IsFrameAddressTaken);
553   MFI.setReturnAddressIsTaken(YamlMFI.IsReturnAddressTaken);
554   MFI.setHasStackMap(YamlMFI.HasStackMap);
555   MFI.setHasPatchPoint(YamlMFI.HasPatchPoint);
556   MFI.setStackSize(YamlMFI.StackSize);
557   MFI.setOffsetAdjustment(YamlMFI.OffsetAdjustment);
558   if (YamlMFI.MaxAlignment)
559     MFI.ensureMaxAlignment(YamlMFI.MaxAlignment);
560   MFI.setAdjustsStack(YamlMFI.AdjustsStack);
561   MFI.setHasCalls(YamlMFI.HasCalls);
562   if (YamlMFI.MaxCallFrameSize != ~0u)
563     MFI.setMaxCallFrameSize(YamlMFI.MaxCallFrameSize);
564   MFI.setHasOpaqueSPAdjustment(YamlMFI.HasOpaqueSPAdjustment);
565   MFI.setHasVAStart(YamlMFI.HasVAStart);
566   MFI.setHasMustTailInVarArgFunc(YamlMFI.HasMustTailInVarArgFunc);
567   if (!YamlMFI.SavePoint.Value.empty()) {
568     MachineBasicBlock *MBB = nullptr;
569     if (parseMBBReference(PFS, MBB, YamlMFI.SavePoint))
570       return true;
571     MFI.setSavePoint(MBB);
572   }
573   if (!YamlMFI.RestorePoint.Value.empty()) {
574     MachineBasicBlock *MBB = nullptr;
575     if (parseMBBReference(PFS, MBB, YamlMFI.RestorePoint))
576       return true;
577     MFI.setRestorePoint(MBB);
578   }
579 
580   std::vector<CalleeSavedInfo> CSIInfo;
581   // Initialize the fixed frame objects.
582   for (const auto &Object : YamlMF.FixedStackObjects) {
583     int ObjectIdx;
584     if (Object.Type != yaml::FixedMachineStackObject::SpillSlot)
585       ObjectIdx = MFI.CreateFixedObject(Object.Size, Object.Offset,
586                                         Object.IsImmutable, Object.IsAliased);
587     else
588       ObjectIdx = MFI.CreateFixedSpillStackObject(Object.Size, Object.Offset);
589     MFI.setObjectAlignment(ObjectIdx, Object.Alignment);
590     if (!PFS.FixedStackObjectSlots.insert(std::make_pair(Object.ID.Value,
591                                                          ObjectIdx))
592              .second)
593       return error(Object.ID.SourceRange.Start,
594                    Twine("redefinition of fixed stack object '%fixed-stack.") +
595                        Twine(Object.ID.Value) + "'");
596     if (parseCalleeSavedRegister(PFS, CSIInfo, Object.CalleeSavedRegister,
597                                  ObjectIdx))
598       return true;
599   }
600 
601   // Initialize the ordinary frame objects.
602   for (const auto &Object : YamlMF.StackObjects) {
603     int ObjectIdx;
604     const AllocaInst *Alloca = nullptr;
605     const yaml::StringValue &Name = Object.Name;
606     if (!Name.Value.empty()) {
607       Alloca = dyn_cast_or_null<AllocaInst>(
608           F.getValueSymbolTable()->lookup(Name.Value));
609       if (!Alloca)
610         return error(Name.SourceRange.Start,
611                      "alloca instruction named '" + Name.Value +
612                          "' isn't defined in the function '" + F.getName() +
613                          "'");
614     }
615     if (Object.Type == yaml::MachineStackObject::VariableSized)
616       ObjectIdx = MFI.CreateVariableSizedObject(Object.Alignment, Alloca);
617     else
618       ObjectIdx = MFI.CreateStackObject(
619           Object.Size, Object.Alignment,
620           Object.Type == yaml::MachineStackObject::SpillSlot, Alloca);
621     MFI.setObjectOffset(ObjectIdx, Object.Offset);
622     if (!PFS.StackObjectSlots.insert(std::make_pair(Object.ID.Value, ObjectIdx))
623              .second)
624       return error(Object.ID.SourceRange.Start,
625                    Twine("redefinition of stack object '%stack.") +
626                        Twine(Object.ID.Value) + "'");
627     if (parseCalleeSavedRegister(PFS, CSIInfo, Object.CalleeSavedRegister,
628                                  ObjectIdx))
629       return true;
630     if (Object.LocalOffset)
631       MFI.mapLocalFrameObject(ObjectIdx, Object.LocalOffset.getValue());
632     if (parseStackObjectsDebugInfo(PFS, Object, ObjectIdx))
633       return true;
634   }
635   MFI.setCalleeSavedInfo(CSIInfo);
636   if (!CSIInfo.empty())
637     MFI.setCalleeSavedInfoValid(true);
638 
639   // Initialize the various stack object references after initializing the
640   // stack objects.
641   if (!YamlMFI.StackProtector.Value.empty()) {
642     SMDiagnostic Error;
643     int FI;
644     if (parseStackObjectReference(PFS, FI, YamlMFI.StackProtector.Value, Error))
645       return error(Error, YamlMFI.StackProtector.SourceRange);
646     MFI.setStackProtectorIndex(FI);
647   }
648   return false;
649 }
650 
651 bool MIRParserImpl::parseCalleeSavedRegister(PerFunctionMIParsingState &PFS,
652     std::vector<CalleeSavedInfo> &CSIInfo,
653     const yaml::StringValue &RegisterSource, int FrameIdx) {
654   if (RegisterSource.Value.empty())
655     return false;
656   unsigned Reg = 0;
657   SMDiagnostic Error;
658   if (parseNamedRegisterReference(PFS, Reg, RegisterSource.Value, Error))
659     return error(Error, RegisterSource.SourceRange);
660   CSIInfo.push_back(CalleeSavedInfo(Reg, FrameIdx));
661   return false;
662 }
663 
664 /// Verify that given node is of a certain type. Return true on error.
665 template <typename T>
666 static bool typecheckMDNode(T *&Result, MDNode *Node,
667                             const yaml::StringValue &Source,
668                             StringRef TypeString, MIRParserImpl &Parser) {
669   if (!Node)
670     return false;
671   Result = dyn_cast<T>(Node);
672   if (!Result)
673     return Parser.error(Source.SourceRange.Start,
674                         "expected a reference to a '" + TypeString +
675                             "' metadata node");
676   return false;
677 }
678 
679 bool MIRParserImpl::parseStackObjectsDebugInfo(PerFunctionMIParsingState &PFS,
680     const yaml::MachineStackObject &Object, int FrameIdx) {
681   // Debug information can only be attached to stack objects; Fixed stack
682   // objects aren't supported.
683   assert(FrameIdx >= 0 && "Expected a stack object frame index");
684   MDNode *Var = nullptr, *Expr = nullptr, *Loc = nullptr;
685   if (parseMDNode(PFS, Var, Object.DebugVar) ||
686       parseMDNode(PFS, Expr, Object.DebugExpr) ||
687       parseMDNode(PFS, Loc, Object.DebugLoc))
688     return true;
689   if (!Var && !Expr && !Loc)
690     return false;
691   DILocalVariable *DIVar = nullptr;
692   DIExpression *DIExpr = nullptr;
693   DILocation *DILoc = nullptr;
694   if (typecheckMDNode(DIVar, Var, Object.DebugVar, "DILocalVariable", *this) ||
695       typecheckMDNode(DIExpr, Expr, Object.DebugExpr, "DIExpression", *this) ||
696       typecheckMDNode(DILoc, Loc, Object.DebugLoc, "DILocation", *this))
697     return true;
698   PFS.MF.setVariableDbgInfo(DIVar, DIExpr, unsigned(FrameIdx), DILoc);
699   return false;
700 }
701 
702 bool MIRParserImpl::parseMDNode(PerFunctionMIParsingState &PFS,
703     MDNode *&Node, const yaml::StringValue &Source) {
704   if (Source.Value.empty())
705     return false;
706   SMDiagnostic Error;
707   if (llvm::parseMDNode(PFS, Node, Source.Value, Error))
708     return error(Error, Source.SourceRange);
709   return false;
710 }
711 
712 bool MIRParserImpl::initializeConstantPool(PerFunctionMIParsingState &PFS,
713     MachineConstantPool &ConstantPool, const yaml::MachineFunction &YamlMF) {
714   DenseMap<unsigned, unsigned> &ConstantPoolSlots = PFS.ConstantPoolSlots;
715   const MachineFunction &MF = PFS.MF;
716   const auto &M = *MF.getFunction()->getParent();
717   SMDiagnostic Error;
718   for (const auto &YamlConstant : YamlMF.Constants) {
719     const Constant *Value = dyn_cast_or_null<Constant>(
720         parseConstantValue(YamlConstant.Value.Value, Error, M));
721     if (!Value)
722       return error(Error, YamlConstant.Value.SourceRange);
723     unsigned Alignment =
724         YamlConstant.Alignment
725             ? YamlConstant.Alignment
726             : M.getDataLayout().getPrefTypeAlignment(Value->getType());
727     unsigned Index = ConstantPool.getConstantPoolIndex(Value, Alignment);
728     if (!ConstantPoolSlots.insert(std::make_pair(YamlConstant.ID.Value, Index))
729              .second)
730       return error(YamlConstant.ID.SourceRange.Start,
731                    Twine("redefinition of constant pool item '%const.") +
732                        Twine(YamlConstant.ID.Value) + "'");
733   }
734   return false;
735 }
736 
737 bool MIRParserImpl::initializeJumpTableInfo(PerFunctionMIParsingState &PFS,
738     const yaml::MachineJumpTable &YamlJTI) {
739   MachineJumpTableInfo *JTI = PFS.MF.getOrCreateJumpTableInfo(YamlJTI.Kind);
740   for (const auto &Entry : YamlJTI.Entries) {
741     std::vector<MachineBasicBlock *> Blocks;
742     for (const auto &MBBSource : Entry.Blocks) {
743       MachineBasicBlock *MBB = nullptr;
744       if (parseMBBReference(PFS, MBB, MBBSource.Value))
745         return true;
746       Blocks.push_back(MBB);
747     }
748     unsigned Index = JTI->createJumpTableIndex(Blocks);
749     if (!PFS.JumpTableSlots.insert(std::make_pair(Entry.ID.Value, Index))
750              .second)
751       return error(Entry.ID.SourceRange.Start,
752                    Twine("redefinition of jump table entry '%jump-table.") +
753                        Twine(Entry.ID.Value) + "'");
754   }
755   return false;
756 }
757 
758 bool MIRParserImpl::parseMBBReference(PerFunctionMIParsingState &PFS,
759                                       MachineBasicBlock *&MBB,
760                                       const yaml::StringValue &Source) {
761   SMDiagnostic Error;
762   if (llvm::parseMBBReference(PFS, MBB, Source.Value, Error))
763     return error(Error, Source.SourceRange);
764   return false;
765 }
766 
767 SMDiagnostic MIRParserImpl::diagFromMIStringDiag(const SMDiagnostic &Error,
768                                                  SMRange SourceRange) {
769   assert(SourceRange.isValid() && "Invalid source range");
770   SMLoc Loc = SourceRange.Start;
771   bool HasQuote = Loc.getPointer() < SourceRange.End.getPointer() &&
772                   *Loc.getPointer() == '\'';
773   // Translate the location of the error from the location in the MI string to
774   // the corresponding location in the MIR file.
775   Loc = Loc.getFromPointer(Loc.getPointer() + Error.getColumnNo() +
776                            (HasQuote ? 1 : 0));
777 
778   // TODO: Translate any source ranges as well.
779   return SM.GetMessage(Loc, Error.getKind(), Error.getMessage(), None,
780                        Error.getFixIts());
781 }
782 
783 SMDiagnostic MIRParserImpl::diagFromBlockStringDiag(const SMDiagnostic &Error,
784                                                     SMRange SourceRange) {
785   assert(SourceRange.isValid());
786 
787   // Translate the location of the error from the location in the llvm IR string
788   // to the corresponding location in the MIR file.
789   auto LineAndColumn = SM.getLineAndColumn(SourceRange.Start);
790   unsigned Line = LineAndColumn.first + Error.getLineNo() - 1;
791   unsigned Column = Error.getColumnNo();
792   StringRef LineStr = Error.getLineContents();
793   SMLoc Loc = Error.getLoc();
794 
795   // Get the full line and adjust the column number by taking the indentation of
796   // LLVM IR into account.
797   for (line_iterator L(*SM.getMemoryBuffer(SM.getMainFileID()), false), E;
798        L != E; ++L) {
799     if (L.line_number() == Line) {
800       LineStr = *L;
801       Loc = SMLoc::getFromPointer(LineStr.data());
802       auto Indent = LineStr.find(Error.getLineContents());
803       if (Indent != StringRef::npos)
804         Column += Indent;
805       break;
806     }
807   }
808 
809   return SMDiagnostic(SM, Loc, Filename, Line, Column, Error.getKind(),
810                       Error.getMessage(), LineStr, Error.getRanges(),
811                       Error.getFixIts());
812 }
813 
814 void MIRParserImpl::initNames2RegClasses(const MachineFunction &MF) {
815   if (!Names2RegClasses.empty())
816     return;
817   const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
818   for (unsigned I = 0, E = TRI->getNumRegClasses(); I < E; ++I) {
819     const auto *RC = TRI->getRegClass(I);
820     Names2RegClasses.insert(
821         std::make_pair(StringRef(TRI->getRegClassName(RC)).lower(), RC));
822   }
823 }
824 
825 void MIRParserImpl::initNames2RegBanks(const MachineFunction &MF) {
826   if (!Names2RegBanks.empty())
827     return;
828   const RegisterBankInfo *RBI = MF.getSubtarget().getRegBankInfo();
829   // If the target does not support GlobalISel, we may not have a
830   // register bank info.
831   if (!RBI)
832     return;
833   for (unsigned I = 0, E = RBI->getNumRegBanks(); I < E; ++I) {
834     const auto &RegBank = RBI->getRegBank(I);
835     Names2RegBanks.insert(
836         std::make_pair(StringRef(RegBank.getName()).lower(), &RegBank));
837   }
838 }
839 
840 const TargetRegisterClass *MIRParserImpl::getRegClass(const MachineFunction &MF,
841                                                       StringRef Name) {
842   auto RegClassInfo = Names2RegClasses.find(Name);
843   if (RegClassInfo == Names2RegClasses.end())
844     return nullptr;
845   return RegClassInfo->getValue();
846 }
847 
848 const RegisterBank *MIRParserImpl::getRegBank(const MachineFunction &MF,
849                                               StringRef Name) {
850   auto RegBankInfo = Names2RegBanks.find(Name);
851   if (RegBankInfo == Names2RegBanks.end())
852     return nullptr;
853   return RegBankInfo->getValue();
854 }
855 
856 MIRParser::MIRParser(std::unique_ptr<MIRParserImpl> Impl)
857     : Impl(std::move(Impl)) {}
858 
859 MIRParser::~MIRParser() {}
860 
861 std::unique_ptr<Module> MIRParser::parseIRModule() {
862   return Impl->parseIRModule();
863 }
864 
865 bool MIRParser::parseMachineFunctions(Module &M, MachineModuleInfo &MMI) {
866   return Impl->parseMachineFunctions(M, MMI);
867 }
868 
869 std::unique_ptr<MIRParser> llvm::createMIRParserFromFile(StringRef Filename,
870                                                          SMDiagnostic &Error,
871                                                          LLVMContext &Context) {
872   auto FileOrErr = MemoryBuffer::getFileOrSTDIN(Filename);
873   if (std::error_code EC = FileOrErr.getError()) {
874     Error = SMDiagnostic(Filename, SourceMgr::DK_Error,
875                          "Could not open input file: " + EC.message());
876     return nullptr;
877   }
878   return createMIRParser(std::move(FileOrErr.get()), Context);
879 }
880 
881 std::unique_ptr<MIRParser>
882 llvm::createMIRParser(std::unique_ptr<MemoryBuffer> Contents,
883                       LLVMContext &Context) {
884   auto Filename = Contents->getBufferIdentifier();
885   if (Context.shouldDiscardValueNames()) {
886     Context.diagnose(DiagnosticInfoMIRParser(
887         DS_Error,
888         SMDiagnostic(
889             Filename, SourceMgr::DK_Error,
890             "Can't read MIR with a Context that discards named Values")));
891     return nullptr;
892   }
893   return llvm::make_unique<MIRParser>(
894       llvm::make_unique<MIRParserImpl>(std::move(Contents), Filename, Context));
895 }
896