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                                 bool IsRestored, 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   case SourceMgr::DK_Remark:
218     llvm_unreachable("remark unexpected");
219     break;
220   }
221   Context.diagnose(DiagnosticInfoMIRParser(Kind, Diag));
222 }
223 
224 std::unique_ptr<Module> MIRParserImpl::parseIRModule() {
225   if (!In.setCurrentDocument()) {
226     if (In.error())
227       return nullptr;
228     // Create an empty module when the MIR file is empty.
229     NoMIRDocuments = true;
230     return llvm::make_unique<Module>(Filename, Context);
231   }
232 
233   std::unique_ptr<Module> M;
234   // Parse the block scalar manually so that we can return unique pointer
235   // without having to go trough YAML traits.
236   if (const auto *BSN =
237           dyn_cast_or_null<yaml::BlockScalarNode>(In.getCurrentNode())) {
238     SMDiagnostic Error;
239     M = parseAssembly(MemoryBufferRef(BSN->getValue(), Filename), Error,
240                       Context, &IRSlots);
241     if (!M) {
242       reportDiagnostic(diagFromBlockStringDiag(Error, BSN->getSourceRange()));
243       return nullptr;
244     }
245     In.nextDocument();
246     if (!In.setCurrentDocument())
247       NoMIRDocuments = true;
248   } else {
249     // Create an new, empty module.
250     M = llvm::make_unique<Module>(Filename, Context);
251     NoLLVMIR = true;
252   }
253   return M;
254 }
255 
256 bool MIRParserImpl::parseMachineFunctions(Module &M, MachineModuleInfo &MMI) {
257   if (NoMIRDocuments)
258     return false;
259 
260   // Parse the machine functions.
261   do {
262     if (parseMachineFunction(M, MMI))
263       return true;
264     In.nextDocument();
265   } while (In.setCurrentDocument());
266 
267   return false;
268 }
269 
270 /// Create an empty function with the given name.
271 static Function *createDummyFunction(StringRef Name, Module &M) {
272   auto &Context = M.getContext();
273   Function *F = cast<Function>(M.getOrInsertFunction(
274       Name, FunctionType::get(Type::getVoidTy(Context), false)));
275   BasicBlock *BB = BasicBlock::Create(Context, "entry", F);
276   new UnreachableInst(Context, BB);
277   return F;
278 }
279 
280 bool MIRParserImpl::parseMachineFunction(Module &M, MachineModuleInfo &MMI) {
281   // Parse the yaml.
282   yaml::MachineFunction YamlMF;
283   yaml::EmptyContext Ctx;
284   yaml::yamlize(In, YamlMF, false, Ctx);
285   if (In.error())
286     return true;
287 
288   // Search for the corresponding IR function.
289   StringRef FunctionName = YamlMF.Name;
290   Function *F = M.getFunction(FunctionName);
291   if (!F) {
292     if (NoLLVMIR) {
293       F = createDummyFunction(FunctionName, M);
294     } else {
295       return error(Twine("function '") + FunctionName +
296                    "' isn't defined in the provided LLVM IR");
297     }
298   }
299   if (MMI.getMachineFunction(*F) != nullptr)
300     return error(Twine("redefinition of machine function '") + FunctionName +
301                  "'");
302 
303   // Create the MachineFunction.
304   MachineFunction &MF = MMI.getOrCreateMachineFunction(*F);
305   if (initializeMachineFunction(YamlMF, MF))
306     return true;
307 
308   return false;
309 }
310 
311 static bool isSSA(const MachineFunction &MF) {
312   const MachineRegisterInfo &MRI = MF.getRegInfo();
313   for (unsigned I = 0, E = MRI.getNumVirtRegs(); I != E; ++I) {
314     unsigned Reg = TargetRegisterInfo::index2VirtReg(I);
315     if (!MRI.hasOneDef(Reg) && !MRI.def_empty(Reg))
316       return false;
317   }
318   return true;
319 }
320 
321 void MIRParserImpl::computeFunctionProperties(MachineFunction &MF) {
322   MachineFunctionProperties &Properties = MF.getProperties();
323 
324   bool HasPHI = false;
325   bool HasInlineAsm = false;
326   for (const MachineBasicBlock &MBB : MF) {
327     for (const MachineInstr &MI : MBB) {
328       if (MI.isPHI())
329         HasPHI = true;
330       if (MI.isInlineAsm())
331         HasInlineAsm = true;
332     }
333   }
334   if (!HasPHI)
335     Properties.set(MachineFunctionProperties::Property::NoPHIs);
336   MF.setHasInlineAsm(HasInlineAsm);
337 
338   if (isSSA(MF))
339     Properties.set(MachineFunctionProperties::Property::IsSSA);
340   else
341     Properties.reset(MachineFunctionProperties::Property::IsSSA);
342 
343   const MachineRegisterInfo &MRI = MF.getRegInfo();
344   if (MRI.getNumVirtRegs() == 0)
345     Properties.set(MachineFunctionProperties::Property::NoVRegs);
346 }
347 
348 bool
349 MIRParserImpl::initializeMachineFunction(const yaml::MachineFunction &YamlMF,
350                                          MachineFunction &MF) {
351   // TODO: Recreate the machine function.
352   initNames2RegClasses(MF);
353   initNames2RegBanks(MF);
354   if (YamlMF.Alignment)
355     MF.setAlignment(YamlMF.Alignment);
356   MF.setExposesReturnsTwice(YamlMF.ExposesReturnsTwice);
357 
358   if (YamlMF.Legalized)
359     MF.getProperties().set(MachineFunctionProperties::Property::Legalized);
360   if (YamlMF.RegBankSelected)
361     MF.getProperties().set(
362         MachineFunctionProperties::Property::RegBankSelected);
363   if (YamlMF.Selected)
364     MF.getProperties().set(MachineFunctionProperties::Property::Selected);
365 
366   PerFunctionMIParsingState PFS(MF, SM, IRSlots, Names2RegClasses,
367                                 Names2RegBanks);
368   if (parseRegisterInfo(PFS, YamlMF))
369     return true;
370   if (!YamlMF.Constants.empty()) {
371     auto *ConstantPool = MF.getConstantPool();
372     assert(ConstantPool && "Constant pool must be created");
373     if (initializeConstantPool(PFS, *ConstantPool, YamlMF))
374       return true;
375   }
376 
377   StringRef BlockStr = YamlMF.Body.Value.Value;
378   SMDiagnostic Error;
379   SourceMgr BlockSM;
380   BlockSM.AddNewSourceBuffer(
381       MemoryBuffer::getMemBuffer(BlockStr, "",/*RequiresNullTerminator=*/false),
382       SMLoc());
383   PFS.SM = &BlockSM;
384   if (parseMachineBasicBlockDefinitions(PFS, BlockStr, Error)) {
385     reportDiagnostic(
386         diagFromBlockStringDiag(Error, YamlMF.Body.Value.SourceRange));
387     return true;
388   }
389   PFS.SM = &SM;
390 
391   // Initialize the frame information after creating all the MBBs so that the
392   // MBB references in the frame information can be resolved.
393   if (initializeFrameInfo(PFS, YamlMF))
394     return true;
395   // Initialize the jump table after creating all the MBBs so that the MBB
396   // references can be resolved.
397   if (!YamlMF.JumpTableInfo.Entries.empty() &&
398       initializeJumpTableInfo(PFS, YamlMF.JumpTableInfo))
399     return true;
400   // Parse the machine instructions after creating all of the MBBs so that the
401   // parser can resolve the MBB references.
402   StringRef InsnStr = YamlMF.Body.Value.Value;
403   SourceMgr InsnSM;
404   InsnSM.AddNewSourceBuffer(
405       MemoryBuffer::getMemBuffer(InsnStr, "", /*RequiresNullTerminator=*/false),
406       SMLoc());
407   PFS.SM = &InsnSM;
408   if (parseMachineInstructions(PFS, InsnStr, Error)) {
409     reportDiagnostic(
410         diagFromBlockStringDiag(Error, YamlMF.Body.Value.SourceRange));
411     return true;
412   }
413   PFS.SM = &SM;
414 
415   if (setupRegisterInfo(PFS, YamlMF))
416     return true;
417 
418   computeFunctionProperties(MF);
419 
420   MF.verify();
421   return false;
422 }
423 
424 bool MIRParserImpl::parseRegisterInfo(PerFunctionMIParsingState &PFS,
425                                       const yaml::MachineFunction &YamlMF) {
426   MachineFunction &MF = PFS.MF;
427   MachineRegisterInfo &RegInfo = MF.getRegInfo();
428   assert(RegInfo.tracksLiveness());
429   if (!YamlMF.TracksRegLiveness)
430     RegInfo.invalidateLiveness();
431 
432   SMDiagnostic Error;
433   // Parse the virtual register information.
434   for (const auto &VReg : YamlMF.VirtualRegisters) {
435     VRegInfo &Info = PFS.getVRegInfo(VReg.ID.Value);
436     if (Info.Explicit)
437       return error(VReg.ID.SourceRange.Start,
438                    Twine("redefinition of virtual register '%") +
439                        Twine(VReg.ID.Value) + "'");
440     Info.Explicit = true;
441 
442     if (StringRef(VReg.Class.Value).equals("_")) {
443       Info.Kind = VRegInfo::GENERIC;
444       Info.D.RegBank = nullptr;
445     } else {
446       const auto *RC = getRegClass(MF, VReg.Class.Value);
447       if (RC) {
448         Info.Kind = VRegInfo::NORMAL;
449         Info.D.RC = RC;
450       } else {
451         const RegisterBank *RegBank = getRegBank(MF, VReg.Class.Value);
452         if (!RegBank)
453           return error(
454               VReg.Class.SourceRange.Start,
455               Twine("use of undefined register class or register bank '") +
456                   VReg.Class.Value + "'");
457         Info.Kind = VRegInfo::REGBANK;
458         Info.D.RegBank = RegBank;
459       }
460     }
461 
462     if (!VReg.PreferredRegister.Value.empty()) {
463       if (Info.Kind != VRegInfo::NORMAL)
464         return error(VReg.Class.SourceRange.Start,
465               Twine("preferred register can only be set for normal vregs"));
466 
467       if (parseRegisterReference(PFS, Info.PreferredReg,
468                                  VReg.PreferredRegister.Value, Error))
469         return error(Error, VReg.PreferredRegister.SourceRange);
470     }
471   }
472 
473   // Parse the liveins.
474   for (const auto &LiveIn : YamlMF.LiveIns) {
475     unsigned Reg = 0;
476     if (parseNamedRegisterReference(PFS, Reg, LiveIn.Register.Value, Error))
477       return error(Error, LiveIn.Register.SourceRange);
478     unsigned VReg = 0;
479     if (!LiveIn.VirtualRegister.Value.empty()) {
480       VRegInfo *Info;
481       if (parseVirtualRegisterReference(PFS, Info, LiveIn.VirtualRegister.Value,
482                                         Error))
483         return error(Error, LiveIn.VirtualRegister.SourceRange);
484       VReg = Info->VReg;
485     }
486     RegInfo.addLiveIn(Reg, VReg);
487   }
488 
489   // Parse the callee saved registers (Registers that will
490   // be saved for the caller).
491   if (YamlMF.CalleeSavedRegisters) {
492     SmallVector<MCPhysReg, 16> CalleeSavedRegisters;
493     for (const auto &RegSource : YamlMF.CalleeSavedRegisters.getValue()) {
494       unsigned Reg = 0;
495       if (parseNamedRegisterReference(PFS, Reg, RegSource.Value, Error))
496         return error(Error, RegSource.SourceRange);
497       CalleeSavedRegisters.push_back(Reg);
498     }
499     RegInfo.setCalleeSavedRegs(CalleeSavedRegisters);
500   }
501 
502   return false;
503 }
504 
505 bool MIRParserImpl::setupRegisterInfo(const PerFunctionMIParsingState &PFS,
506                                       const yaml::MachineFunction &YamlMF) {
507   MachineFunction &MF = PFS.MF;
508   MachineRegisterInfo &MRI = MF.getRegInfo();
509   bool Error = false;
510   // Create VRegs
511   for (auto P : PFS.VRegInfos) {
512     const VRegInfo &Info = *P.second;
513     unsigned Reg = Info.VReg;
514     switch (Info.Kind) {
515     case VRegInfo::UNKNOWN:
516       error(Twine("Cannot determine class/bank of virtual register ") +
517             Twine(P.first) + " in function '" + MF.getName() + "'");
518       Error = true;
519       break;
520     case VRegInfo::NORMAL:
521       MRI.setRegClass(Reg, Info.D.RC);
522       if (Info.PreferredReg != 0)
523         MRI.setSimpleHint(Reg, Info.PreferredReg);
524       break;
525     case VRegInfo::GENERIC:
526       break;
527     case VRegInfo::REGBANK:
528       MRI.setRegBank(Reg, *Info.D.RegBank);
529       break;
530     }
531   }
532 
533   // Compute MachineRegisterInfo::UsedPhysRegMask
534   for (const MachineBasicBlock &MBB : MF) {
535     for (const MachineInstr &MI : MBB) {
536       for (const MachineOperand &MO : MI.operands()) {
537         if (!MO.isRegMask())
538           continue;
539         MRI.addPhysRegsUsedFromRegMask(MO.getRegMask());
540       }
541     }
542   }
543 
544   // FIXME: This is a temporary workaround until the reserved registers can be
545   // serialized.
546   MRI.freezeReservedRegs(MF);
547   return Error;
548 }
549 
550 bool MIRParserImpl::initializeFrameInfo(PerFunctionMIParsingState &PFS,
551                                         const yaml::MachineFunction &YamlMF) {
552   MachineFunction &MF = PFS.MF;
553   MachineFrameInfo &MFI = MF.getFrameInfo();
554   const Function &F = MF.getFunction();
555   const yaml::MachineFrameInfo &YamlMFI = YamlMF.FrameInfo;
556   MFI.setFrameAddressIsTaken(YamlMFI.IsFrameAddressTaken);
557   MFI.setReturnAddressIsTaken(YamlMFI.IsReturnAddressTaken);
558   MFI.setHasStackMap(YamlMFI.HasStackMap);
559   MFI.setHasPatchPoint(YamlMFI.HasPatchPoint);
560   MFI.setStackSize(YamlMFI.StackSize);
561   MFI.setOffsetAdjustment(YamlMFI.OffsetAdjustment);
562   if (YamlMFI.MaxAlignment)
563     MFI.ensureMaxAlignment(YamlMFI.MaxAlignment);
564   MFI.setAdjustsStack(YamlMFI.AdjustsStack);
565   MFI.setHasCalls(YamlMFI.HasCalls);
566   if (YamlMFI.MaxCallFrameSize != ~0u)
567     MFI.setMaxCallFrameSize(YamlMFI.MaxCallFrameSize);
568   MFI.setHasOpaqueSPAdjustment(YamlMFI.HasOpaqueSPAdjustment);
569   MFI.setHasVAStart(YamlMFI.HasVAStart);
570   MFI.setHasMustTailInVarArgFunc(YamlMFI.HasMustTailInVarArgFunc);
571   if (!YamlMFI.SavePoint.Value.empty()) {
572     MachineBasicBlock *MBB = nullptr;
573     if (parseMBBReference(PFS, MBB, YamlMFI.SavePoint))
574       return true;
575     MFI.setSavePoint(MBB);
576   }
577   if (!YamlMFI.RestorePoint.Value.empty()) {
578     MachineBasicBlock *MBB = nullptr;
579     if (parseMBBReference(PFS, MBB, YamlMFI.RestorePoint))
580       return true;
581     MFI.setRestorePoint(MBB);
582   }
583 
584   std::vector<CalleeSavedInfo> CSIInfo;
585   // Initialize the fixed frame objects.
586   for (const auto &Object : YamlMF.FixedStackObjects) {
587     int ObjectIdx;
588     if (Object.Type != yaml::FixedMachineStackObject::SpillSlot)
589       ObjectIdx = MFI.CreateFixedObject(Object.Size, Object.Offset,
590                                         Object.IsImmutable, Object.IsAliased);
591     else
592       ObjectIdx = MFI.CreateFixedSpillStackObject(Object.Size, Object.Offset);
593     MFI.setObjectAlignment(ObjectIdx, Object.Alignment);
594     MFI.setStackID(ObjectIdx, Object.StackID);
595     if (!PFS.FixedStackObjectSlots.insert(std::make_pair(Object.ID.Value,
596                                                          ObjectIdx))
597              .second)
598       return error(Object.ID.SourceRange.Start,
599                    Twine("redefinition of fixed stack object '%fixed-stack.") +
600                        Twine(Object.ID.Value) + "'");
601     if (parseCalleeSavedRegister(PFS, CSIInfo, Object.CalleeSavedRegister,
602                                  Object.CalleeSavedRestored, ObjectIdx))
603       return true;
604   }
605 
606   // Initialize the ordinary frame objects.
607   for (const auto &Object : YamlMF.StackObjects) {
608     int ObjectIdx;
609     const AllocaInst *Alloca = nullptr;
610     const yaml::StringValue &Name = Object.Name;
611     if (!Name.Value.empty()) {
612       Alloca = dyn_cast_or_null<AllocaInst>(
613           F.getValueSymbolTable()->lookup(Name.Value));
614       if (!Alloca)
615         return error(Name.SourceRange.Start,
616                      "alloca instruction named '" + Name.Value +
617                          "' isn't defined in the function '" + F.getName() +
618                          "'");
619     }
620     if (Object.Type == yaml::MachineStackObject::VariableSized)
621       ObjectIdx = MFI.CreateVariableSizedObject(Object.Alignment, Alloca);
622     else
623       ObjectIdx = MFI.CreateStackObject(
624           Object.Size, Object.Alignment,
625           Object.Type == yaml::MachineStackObject::SpillSlot, Alloca);
626     MFI.setObjectOffset(ObjectIdx, Object.Offset);
627     MFI.setStackID(ObjectIdx, Object.StackID);
628 
629     if (!PFS.StackObjectSlots.insert(std::make_pair(Object.ID.Value, ObjectIdx))
630              .second)
631       return error(Object.ID.SourceRange.Start,
632                    Twine("redefinition of stack object '%stack.") +
633                        Twine(Object.ID.Value) + "'");
634     if (parseCalleeSavedRegister(PFS, CSIInfo, Object.CalleeSavedRegister,
635                                  Object.CalleeSavedRestored, ObjectIdx))
636       return true;
637     if (Object.LocalOffset)
638       MFI.mapLocalFrameObject(ObjectIdx, Object.LocalOffset.getValue());
639     if (parseStackObjectsDebugInfo(PFS, Object, ObjectIdx))
640       return true;
641   }
642   MFI.setCalleeSavedInfo(CSIInfo);
643   if (!CSIInfo.empty())
644     MFI.setCalleeSavedInfoValid(true);
645 
646   // Initialize the various stack object references after initializing the
647   // stack objects.
648   if (!YamlMFI.StackProtector.Value.empty()) {
649     SMDiagnostic Error;
650     int FI;
651     if (parseStackObjectReference(PFS, FI, YamlMFI.StackProtector.Value, Error))
652       return error(Error, YamlMFI.StackProtector.SourceRange);
653     MFI.setStackProtectorIndex(FI);
654   }
655   return false;
656 }
657 
658 bool MIRParserImpl::parseCalleeSavedRegister(PerFunctionMIParsingState &PFS,
659     std::vector<CalleeSavedInfo> &CSIInfo,
660     const yaml::StringValue &RegisterSource, bool IsRestored, int FrameIdx) {
661   if (RegisterSource.Value.empty())
662     return false;
663   unsigned Reg = 0;
664   SMDiagnostic Error;
665   if (parseNamedRegisterReference(PFS, Reg, RegisterSource.Value, Error))
666     return error(Error, RegisterSource.SourceRange);
667   CalleeSavedInfo CSI(Reg, FrameIdx);
668   CSI.setRestored(IsRestored);
669   CSIInfo.push_back(CSI);
670   return false;
671 }
672 
673 /// Verify that given node is of a certain type. Return true on error.
674 template <typename T>
675 static bool typecheckMDNode(T *&Result, MDNode *Node,
676                             const yaml::StringValue &Source,
677                             StringRef TypeString, MIRParserImpl &Parser) {
678   if (!Node)
679     return false;
680   Result = dyn_cast<T>(Node);
681   if (!Result)
682     return Parser.error(Source.SourceRange.Start,
683                         "expected a reference to a '" + TypeString +
684                             "' metadata node");
685   return false;
686 }
687 
688 bool MIRParserImpl::parseStackObjectsDebugInfo(PerFunctionMIParsingState &PFS,
689     const yaml::MachineStackObject &Object, int FrameIdx) {
690   // Debug information can only be attached to stack objects; Fixed stack
691   // objects aren't supported.
692   assert(FrameIdx >= 0 && "Expected a stack object frame index");
693   MDNode *Var = nullptr, *Expr = nullptr, *Loc = nullptr;
694   if (parseMDNode(PFS, Var, Object.DebugVar) ||
695       parseMDNode(PFS, Expr, Object.DebugExpr) ||
696       parseMDNode(PFS, Loc, Object.DebugLoc))
697     return true;
698   if (!Var && !Expr && !Loc)
699     return false;
700   DILocalVariable *DIVar = nullptr;
701   DIExpression *DIExpr = nullptr;
702   DILocation *DILoc = nullptr;
703   if (typecheckMDNode(DIVar, Var, Object.DebugVar, "DILocalVariable", *this) ||
704       typecheckMDNode(DIExpr, Expr, Object.DebugExpr, "DIExpression", *this) ||
705       typecheckMDNode(DILoc, Loc, Object.DebugLoc, "DILocation", *this))
706     return true;
707   PFS.MF.setVariableDbgInfo(DIVar, DIExpr, unsigned(FrameIdx), DILoc);
708   return false;
709 }
710 
711 bool MIRParserImpl::parseMDNode(PerFunctionMIParsingState &PFS,
712     MDNode *&Node, const yaml::StringValue &Source) {
713   if (Source.Value.empty())
714     return false;
715   SMDiagnostic Error;
716   if (llvm::parseMDNode(PFS, Node, Source.Value, Error))
717     return error(Error, Source.SourceRange);
718   return false;
719 }
720 
721 bool MIRParserImpl::initializeConstantPool(PerFunctionMIParsingState &PFS,
722     MachineConstantPool &ConstantPool, const yaml::MachineFunction &YamlMF) {
723   DenseMap<unsigned, unsigned> &ConstantPoolSlots = PFS.ConstantPoolSlots;
724   const MachineFunction &MF = PFS.MF;
725   const auto &M = *MF.getFunction().getParent();
726   SMDiagnostic Error;
727   for (const auto &YamlConstant : YamlMF.Constants) {
728     if (YamlConstant.IsTargetSpecific)
729       // FIXME: Support target-specific constant pools
730       return error(YamlConstant.Value.SourceRange.Start,
731                    "Can't parse target-specific constant pool entries yet");
732     const Constant *Value = dyn_cast_or_null<Constant>(
733         parseConstantValue(YamlConstant.Value.Value, Error, M));
734     if (!Value)
735       return error(Error, YamlConstant.Value.SourceRange);
736     unsigned Alignment =
737         YamlConstant.Alignment
738             ? YamlConstant.Alignment
739             : M.getDataLayout().getPrefTypeAlignment(Value->getType());
740     unsigned Index = ConstantPool.getConstantPoolIndex(Value, Alignment);
741     if (!ConstantPoolSlots.insert(std::make_pair(YamlConstant.ID.Value, Index))
742              .second)
743       return error(YamlConstant.ID.SourceRange.Start,
744                    Twine("redefinition of constant pool item '%const.") +
745                        Twine(YamlConstant.ID.Value) + "'");
746   }
747   return false;
748 }
749 
750 bool MIRParserImpl::initializeJumpTableInfo(PerFunctionMIParsingState &PFS,
751     const yaml::MachineJumpTable &YamlJTI) {
752   MachineJumpTableInfo *JTI = PFS.MF.getOrCreateJumpTableInfo(YamlJTI.Kind);
753   for (const auto &Entry : YamlJTI.Entries) {
754     std::vector<MachineBasicBlock *> Blocks;
755     for (const auto &MBBSource : Entry.Blocks) {
756       MachineBasicBlock *MBB = nullptr;
757       if (parseMBBReference(PFS, MBB, MBBSource.Value))
758         return true;
759       Blocks.push_back(MBB);
760     }
761     unsigned Index = JTI->createJumpTableIndex(Blocks);
762     if (!PFS.JumpTableSlots.insert(std::make_pair(Entry.ID.Value, Index))
763              .second)
764       return error(Entry.ID.SourceRange.Start,
765                    Twine("redefinition of jump table entry '%jump-table.") +
766                        Twine(Entry.ID.Value) + "'");
767   }
768   return false;
769 }
770 
771 bool MIRParserImpl::parseMBBReference(PerFunctionMIParsingState &PFS,
772                                       MachineBasicBlock *&MBB,
773                                       const yaml::StringValue &Source) {
774   SMDiagnostic Error;
775   if (llvm::parseMBBReference(PFS, MBB, Source.Value, Error))
776     return error(Error, Source.SourceRange);
777   return false;
778 }
779 
780 SMDiagnostic MIRParserImpl::diagFromMIStringDiag(const SMDiagnostic &Error,
781                                                  SMRange SourceRange) {
782   assert(SourceRange.isValid() && "Invalid source range");
783   SMLoc Loc = SourceRange.Start;
784   bool HasQuote = Loc.getPointer() < SourceRange.End.getPointer() &&
785                   *Loc.getPointer() == '\'';
786   // Translate the location of the error from the location in the MI string to
787   // the corresponding location in the MIR file.
788   Loc = Loc.getFromPointer(Loc.getPointer() + Error.getColumnNo() +
789                            (HasQuote ? 1 : 0));
790 
791   // TODO: Translate any source ranges as well.
792   return SM.GetMessage(Loc, Error.getKind(), Error.getMessage(), None,
793                        Error.getFixIts());
794 }
795 
796 SMDiagnostic MIRParserImpl::diagFromBlockStringDiag(const SMDiagnostic &Error,
797                                                     SMRange SourceRange) {
798   assert(SourceRange.isValid());
799 
800   // Translate the location of the error from the location in the llvm IR string
801   // to the corresponding location in the MIR file.
802   auto LineAndColumn = SM.getLineAndColumn(SourceRange.Start);
803   unsigned Line = LineAndColumn.first + Error.getLineNo() - 1;
804   unsigned Column = Error.getColumnNo();
805   StringRef LineStr = Error.getLineContents();
806   SMLoc Loc = Error.getLoc();
807 
808   // Get the full line and adjust the column number by taking the indentation of
809   // LLVM IR into account.
810   for (line_iterator L(*SM.getMemoryBuffer(SM.getMainFileID()), false), E;
811        L != E; ++L) {
812     if (L.line_number() == Line) {
813       LineStr = *L;
814       Loc = SMLoc::getFromPointer(LineStr.data());
815       auto Indent = LineStr.find(Error.getLineContents());
816       if (Indent != StringRef::npos)
817         Column += Indent;
818       break;
819     }
820   }
821 
822   return SMDiagnostic(SM, Loc, Filename, Line, Column, Error.getKind(),
823                       Error.getMessage(), LineStr, Error.getRanges(),
824                       Error.getFixIts());
825 }
826 
827 void MIRParserImpl::initNames2RegClasses(const MachineFunction &MF) {
828   if (!Names2RegClasses.empty())
829     return;
830   const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
831   for (unsigned I = 0, E = TRI->getNumRegClasses(); I < E; ++I) {
832     const auto *RC = TRI->getRegClass(I);
833     Names2RegClasses.insert(
834         std::make_pair(StringRef(TRI->getRegClassName(RC)).lower(), RC));
835   }
836 }
837 
838 void MIRParserImpl::initNames2RegBanks(const MachineFunction &MF) {
839   if (!Names2RegBanks.empty())
840     return;
841   const RegisterBankInfo *RBI = MF.getSubtarget().getRegBankInfo();
842   // If the target does not support GlobalISel, we may not have a
843   // register bank info.
844   if (!RBI)
845     return;
846   for (unsigned I = 0, E = RBI->getNumRegBanks(); I < E; ++I) {
847     const auto &RegBank = RBI->getRegBank(I);
848     Names2RegBanks.insert(
849         std::make_pair(StringRef(RegBank.getName()).lower(), &RegBank));
850   }
851 }
852 
853 const TargetRegisterClass *MIRParserImpl::getRegClass(const MachineFunction &MF,
854                                                       StringRef Name) {
855   auto RegClassInfo = Names2RegClasses.find(Name);
856   if (RegClassInfo == Names2RegClasses.end())
857     return nullptr;
858   return RegClassInfo->getValue();
859 }
860 
861 const RegisterBank *MIRParserImpl::getRegBank(const MachineFunction &MF,
862                                               StringRef Name) {
863   auto RegBankInfo = Names2RegBanks.find(Name);
864   if (RegBankInfo == Names2RegBanks.end())
865     return nullptr;
866   return RegBankInfo->getValue();
867 }
868 
869 MIRParser::MIRParser(std::unique_ptr<MIRParserImpl> Impl)
870     : Impl(std::move(Impl)) {}
871 
872 MIRParser::~MIRParser() {}
873 
874 std::unique_ptr<Module> MIRParser::parseIRModule() {
875   return Impl->parseIRModule();
876 }
877 
878 bool MIRParser::parseMachineFunctions(Module &M, MachineModuleInfo &MMI) {
879   return Impl->parseMachineFunctions(M, MMI);
880 }
881 
882 std::unique_ptr<MIRParser> llvm::createMIRParserFromFile(StringRef Filename,
883                                                          SMDiagnostic &Error,
884                                                          LLVMContext &Context) {
885   auto FileOrErr = MemoryBuffer::getFileOrSTDIN(Filename);
886   if (std::error_code EC = FileOrErr.getError()) {
887     Error = SMDiagnostic(Filename, SourceMgr::DK_Error,
888                          "Could not open input file: " + EC.message());
889     return nullptr;
890   }
891   return createMIRParser(std::move(FileOrErr.get()), Context);
892 }
893 
894 std::unique_ptr<MIRParser>
895 llvm::createMIRParser(std::unique_ptr<MemoryBuffer> Contents,
896                       LLVMContext &Context) {
897   auto Filename = Contents->getBufferIdentifier();
898   if (Context.shouldDiscardValueNames()) {
899     Context.diagnose(DiagnosticInfoMIRParser(
900         DS_Error,
901         SMDiagnostic(
902             Filename, SourceMgr::DK_Error,
903             "Can't read MIR with a Context that discards named Values")));
904     return nullptr;
905   }
906   return llvm::make_unique<MIRParser>(
907       llvm::make_unique<MIRParserImpl>(std::move(Contents), Filename, Context));
908 }
909