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, /*UpgradeDebugInfo=*/false);
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   if (YamlMF.FailedISel)
366     MF.getProperties().set(MachineFunctionProperties::Property::FailedISel);
367 
368   PerFunctionMIParsingState PFS(MF, SM, IRSlots, Names2RegClasses,
369                                 Names2RegBanks);
370   if (parseRegisterInfo(PFS, YamlMF))
371     return true;
372   if (!YamlMF.Constants.empty()) {
373     auto *ConstantPool = MF.getConstantPool();
374     assert(ConstantPool && "Constant pool must be created");
375     if (initializeConstantPool(PFS, *ConstantPool, YamlMF))
376       return true;
377   }
378 
379   StringRef BlockStr = YamlMF.Body.Value.Value;
380   SMDiagnostic Error;
381   SourceMgr BlockSM;
382   BlockSM.AddNewSourceBuffer(
383       MemoryBuffer::getMemBuffer(BlockStr, "",/*RequiresNullTerminator=*/false),
384       SMLoc());
385   PFS.SM = &BlockSM;
386   if (parseMachineBasicBlockDefinitions(PFS, BlockStr, Error)) {
387     reportDiagnostic(
388         diagFromBlockStringDiag(Error, YamlMF.Body.Value.SourceRange));
389     return true;
390   }
391   PFS.SM = &SM;
392 
393   // Initialize the frame information after creating all the MBBs so that the
394   // MBB references in the frame information can be resolved.
395   if (initializeFrameInfo(PFS, YamlMF))
396     return true;
397   // Initialize the jump table after creating all the MBBs so that the MBB
398   // references can be resolved.
399   if (!YamlMF.JumpTableInfo.Entries.empty() &&
400       initializeJumpTableInfo(PFS, YamlMF.JumpTableInfo))
401     return true;
402   // Parse the machine instructions after creating all of the MBBs so that the
403   // parser can resolve the MBB references.
404   StringRef InsnStr = YamlMF.Body.Value.Value;
405   SourceMgr InsnSM;
406   InsnSM.AddNewSourceBuffer(
407       MemoryBuffer::getMemBuffer(InsnStr, "", /*RequiresNullTerminator=*/false),
408       SMLoc());
409   PFS.SM = &InsnSM;
410   if (parseMachineInstructions(PFS, InsnStr, Error)) {
411     reportDiagnostic(
412         diagFromBlockStringDiag(Error, YamlMF.Body.Value.SourceRange));
413     return true;
414   }
415   PFS.SM = &SM;
416 
417   if (setupRegisterInfo(PFS, YamlMF))
418     return true;
419 
420   computeFunctionProperties(MF);
421 
422   MF.getSubtarget().mirFileLoaded(MF);
423 
424   MF.verify();
425   return false;
426 }
427 
428 bool MIRParserImpl::parseRegisterInfo(PerFunctionMIParsingState &PFS,
429                                       const yaml::MachineFunction &YamlMF) {
430   MachineFunction &MF = PFS.MF;
431   MachineRegisterInfo &RegInfo = MF.getRegInfo();
432   assert(RegInfo.tracksLiveness());
433   if (!YamlMF.TracksRegLiveness)
434     RegInfo.invalidateLiveness();
435 
436   SMDiagnostic Error;
437   // Parse the virtual register information.
438   for (const auto &VReg : YamlMF.VirtualRegisters) {
439     VRegInfo &Info = PFS.getVRegInfo(VReg.ID.Value);
440     if (Info.Explicit)
441       return error(VReg.ID.SourceRange.Start,
442                    Twine("redefinition of virtual register '%") +
443                        Twine(VReg.ID.Value) + "'");
444     Info.Explicit = true;
445 
446     if (StringRef(VReg.Class.Value).equals("_")) {
447       Info.Kind = VRegInfo::GENERIC;
448       Info.D.RegBank = nullptr;
449     } else {
450       const auto *RC = getRegClass(MF, VReg.Class.Value);
451       if (RC) {
452         Info.Kind = VRegInfo::NORMAL;
453         Info.D.RC = RC;
454       } else {
455         const RegisterBank *RegBank = getRegBank(MF, VReg.Class.Value);
456         if (!RegBank)
457           return error(
458               VReg.Class.SourceRange.Start,
459               Twine("use of undefined register class or register bank '") +
460                   VReg.Class.Value + "'");
461         Info.Kind = VRegInfo::REGBANK;
462         Info.D.RegBank = RegBank;
463       }
464     }
465 
466     if (!VReg.PreferredRegister.Value.empty()) {
467       if (Info.Kind != VRegInfo::NORMAL)
468         return error(VReg.Class.SourceRange.Start,
469               Twine("preferred register can only be set for normal vregs"));
470 
471       if (parseRegisterReference(PFS, Info.PreferredReg,
472                                  VReg.PreferredRegister.Value, Error))
473         return error(Error, VReg.PreferredRegister.SourceRange);
474     }
475   }
476 
477   // Parse the liveins.
478   for (const auto &LiveIn : YamlMF.LiveIns) {
479     unsigned Reg = 0;
480     if (parseNamedRegisterReference(PFS, Reg, LiveIn.Register.Value, Error))
481       return error(Error, LiveIn.Register.SourceRange);
482     unsigned VReg = 0;
483     if (!LiveIn.VirtualRegister.Value.empty()) {
484       VRegInfo *Info;
485       if (parseVirtualRegisterReference(PFS, Info, LiveIn.VirtualRegister.Value,
486                                         Error))
487         return error(Error, LiveIn.VirtualRegister.SourceRange);
488       VReg = Info->VReg;
489     }
490     RegInfo.addLiveIn(Reg, VReg);
491   }
492 
493   // Parse the callee saved registers (Registers that will
494   // be saved for the caller).
495   if (YamlMF.CalleeSavedRegisters) {
496     SmallVector<MCPhysReg, 16> CalleeSavedRegisters;
497     for (const auto &RegSource : YamlMF.CalleeSavedRegisters.getValue()) {
498       unsigned Reg = 0;
499       if (parseNamedRegisterReference(PFS, Reg, RegSource.Value, Error))
500         return error(Error, RegSource.SourceRange);
501       CalleeSavedRegisters.push_back(Reg);
502     }
503     RegInfo.setCalleeSavedRegs(CalleeSavedRegisters);
504   }
505 
506   return false;
507 }
508 
509 bool MIRParserImpl::setupRegisterInfo(const PerFunctionMIParsingState &PFS,
510                                       const yaml::MachineFunction &YamlMF) {
511   MachineFunction &MF = PFS.MF;
512   MachineRegisterInfo &MRI = MF.getRegInfo();
513   bool Error = false;
514   // Create VRegs
515   for (auto P : PFS.VRegInfos) {
516     const VRegInfo &Info = *P.second;
517     unsigned Reg = Info.VReg;
518     switch (Info.Kind) {
519     case VRegInfo::UNKNOWN:
520       error(Twine("Cannot determine class/bank of virtual register ") +
521             Twine(P.first) + " in function '" + MF.getName() + "'");
522       Error = true;
523       break;
524     case VRegInfo::NORMAL:
525       MRI.setRegClass(Reg, Info.D.RC);
526       if (Info.PreferredReg != 0)
527         MRI.setSimpleHint(Reg, Info.PreferredReg);
528       break;
529     case VRegInfo::GENERIC:
530       break;
531     case VRegInfo::REGBANK:
532       MRI.setRegBank(Reg, *Info.D.RegBank);
533       break;
534     }
535   }
536 
537   // Compute MachineRegisterInfo::UsedPhysRegMask
538   for (const MachineBasicBlock &MBB : MF) {
539     for (const MachineInstr &MI : MBB) {
540       for (const MachineOperand &MO : MI.operands()) {
541         if (!MO.isRegMask())
542           continue;
543         MRI.addPhysRegsUsedFromRegMask(MO.getRegMask());
544       }
545     }
546   }
547 
548   // FIXME: This is a temporary workaround until the reserved registers can be
549   // serialized.
550   MRI.freezeReservedRegs(MF);
551   return Error;
552 }
553 
554 bool MIRParserImpl::initializeFrameInfo(PerFunctionMIParsingState &PFS,
555                                         const yaml::MachineFunction &YamlMF) {
556   MachineFunction &MF = PFS.MF;
557   MachineFrameInfo &MFI = MF.getFrameInfo();
558   const Function &F = MF.getFunction();
559   const yaml::MachineFrameInfo &YamlMFI = YamlMF.FrameInfo;
560   MFI.setFrameAddressIsTaken(YamlMFI.IsFrameAddressTaken);
561   MFI.setReturnAddressIsTaken(YamlMFI.IsReturnAddressTaken);
562   MFI.setHasStackMap(YamlMFI.HasStackMap);
563   MFI.setHasPatchPoint(YamlMFI.HasPatchPoint);
564   MFI.setStackSize(YamlMFI.StackSize);
565   MFI.setOffsetAdjustment(YamlMFI.OffsetAdjustment);
566   if (YamlMFI.MaxAlignment)
567     MFI.ensureMaxAlignment(YamlMFI.MaxAlignment);
568   MFI.setAdjustsStack(YamlMFI.AdjustsStack);
569   MFI.setHasCalls(YamlMFI.HasCalls);
570   if (YamlMFI.MaxCallFrameSize != ~0u)
571     MFI.setMaxCallFrameSize(YamlMFI.MaxCallFrameSize);
572   MFI.setHasOpaqueSPAdjustment(YamlMFI.HasOpaqueSPAdjustment);
573   MFI.setHasVAStart(YamlMFI.HasVAStart);
574   MFI.setHasMustTailInVarArgFunc(YamlMFI.HasMustTailInVarArgFunc);
575   if (!YamlMFI.SavePoint.Value.empty()) {
576     MachineBasicBlock *MBB = nullptr;
577     if (parseMBBReference(PFS, MBB, YamlMFI.SavePoint))
578       return true;
579     MFI.setSavePoint(MBB);
580   }
581   if (!YamlMFI.RestorePoint.Value.empty()) {
582     MachineBasicBlock *MBB = nullptr;
583     if (parseMBBReference(PFS, MBB, YamlMFI.RestorePoint))
584       return true;
585     MFI.setRestorePoint(MBB);
586   }
587 
588   std::vector<CalleeSavedInfo> CSIInfo;
589   // Initialize the fixed frame objects.
590   for (const auto &Object : YamlMF.FixedStackObjects) {
591     int ObjectIdx;
592     if (Object.Type != yaml::FixedMachineStackObject::SpillSlot)
593       ObjectIdx = MFI.CreateFixedObject(Object.Size, Object.Offset,
594                                         Object.IsImmutable, Object.IsAliased);
595     else
596       ObjectIdx = MFI.CreateFixedSpillStackObject(Object.Size, Object.Offset);
597     MFI.setObjectAlignment(ObjectIdx, Object.Alignment);
598     MFI.setStackID(ObjectIdx, Object.StackID);
599     if (!PFS.FixedStackObjectSlots.insert(std::make_pair(Object.ID.Value,
600                                                          ObjectIdx))
601              .second)
602       return error(Object.ID.SourceRange.Start,
603                    Twine("redefinition of fixed stack object '%fixed-stack.") +
604                        Twine(Object.ID.Value) + "'");
605     if (parseCalleeSavedRegister(PFS, CSIInfo, Object.CalleeSavedRegister,
606                                  Object.CalleeSavedRestored, ObjectIdx))
607       return true;
608   }
609 
610   // Initialize the ordinary frame objects.
611   for (const auto &Object : YamlMF.StackObjects) {
612     int ObjectIdx;
613     const AllocaInst *Alloca = nullptr;
614     const yaml::StringValue &Name = Object.Name;
615     if (!Name.Value.empty()) {
616       Alloca = dyn_cast_or_null<AllocaInst>(
617           F.getValueSymbolTable()->lookup(Name.Value));
618       if (!Alloca)
619         return error(Name.SourceRange.Start,
620                      "alloca instruction named '" + Name.Value +
621                          "' isn't defined in the function '" + F.getName() +
622                          "'");
623     }
624     if (Object.Type == yaml::MachineStackObject::VariableSized)
625       ObjectIdx = MFI.CreateVariableSizedObject(Object.Alignment, Alloca);
626     else
627       ObjectIdx = MFI.CreateStackObject(
628           Object.Size, Object.Alignment,
629           Object.Type == yaml::MachineStackObject::SpillSlot, Alloca);
630     MFI.setObjectOffset(ObjectIdx, Object.Offset);
631     MFI.setStackID(ObjectIdx, Object.StackID);
632 
633     if (!PFS.StackObjectSlots.insert(std::make_pair(Object.ID.Value, ObjectIdx))
634              .second)
635       return error(Object.ID.SourceRange.Start,
636                    Twine("redefinition of stack object '%stack.") +
637                        Twine(Object.ID.Value) + "'");
638     if (parseCalleeSavedRegister(PFS, CSIInfo, Object.CalleeSavedRegister,
639                                  Object.CalleeSavedRestored, ObjectIdx))
640       return true;
641     if (Object.LocalOffset)
642       MFI.mapLocalFrameObject(ObjectIdx, Object.LocalOffset.getValue());
643     if (parseStackObjectsDebugInfo(PFS, Object, ObjectIdx))
644       return true;
645   }
646   MFI.setCalleeSavedInfo(CSIInfo);
647   if (!CSIInfo.empty())
648     MFI.setCalleeSavedInfoValid(true);
649 
650   // Initialize the various stack object references after initializing the
651   // stack objects.
652   if (!YamlMFI.StackProtector.Value.empty()) {
653     SMDiagnostic Error;
654     int FI;
655     if (parseStackObjectReference(PFS, FI, YamlMFI.StackProtector.Value, Error))
656       return error(Error, YamlMFI.StackProtector.SourceRange);
657     MFI.setStackProtectorIndex(FI);
658   }
659   return false;
660 }
661 
662 bool MIRParserImpl::parseCalleeSavedRegister(PerFunctionMIParsingState &PFS,
663     std::vector<CalleeSavedInfo> &CSIInfo,
664     const yaml::StringValue &RegisterSource, bool IsRestored, int FrameIdx) {
665   if (RegisterSource.Value.empty())
666     return false;
667   unsigned Reg = 0;
668   SMDiagnostic Error;
669   if (parseNamedRegisterReference(PFS, Reg, RegisterSource.Value, Error))
670     return error(Error, RegisterSource.SourceRange);
671   CalleeSavedInfo CSI(Reg, FrameIdx);
672   CSI.setRestored(IsRestored);
673   CSIInfo.push_back(CSI);
674   return false;
675 }
676 
677 /// Verify that given node is of a certain type. Return true on error.
678 template <typename T>
679 static bool typecheckMDNode(T *&Result, MDNode *Node,
680                             const yaml::StringValue &Source,
681                             StringRef TypeString, MIRParserImpl &Parser) {
682   if (!Node)
683     return false;
684   Result = dyn_cast<T>(Node);
685   if (!Result)
686     return Parser.error(Source.SourceRange.Start,
687                         "expected a reference to a '" + TypeString +
688                             "' metadata node");
689   return false;
690 }
691 
692 bool MIRParserImpl::parseStackObjectsDebugInfo(PerFunctionMIParsingState &PFS,
693     const yaml::MachineStackObject &Object, int FrameIdx) {
694   // Debug information can only be attached to stack objects; Fixed stack
695   // objects aren't supported.
696   assert(FrameIdx >= 0 && "Expected a stack object frame index");
697   MDNode *Var = nullptr, *Expr = nullptr, *Loc = nullptr;
698   if (parseMDNode(PFS, Var, Object.DebugVar) ||
699       parseMDNode(PFS, Expr, Object.DebugExpr) ||
700       parseMDNode(PFS, Loc, Object.DebugLoc))
701     return true;
702   if (!Var && !Expr && !Loc)
703     return false;
704   DILocalVariable *DIVar = nullptr;
705   DIExpression *DIExpr = nullptr;
706   DILocation *DILoc = nullptr;
707   if (typecheckMDNode(DIVar, Var, Object.DebugVar, "DILocalVariable", *this) ||
708       typecheckMDNode(DIExpr, Expr, Object.DebugExpr, "DIExpression", *this) ||
709       typecheckMDNode(DILoc, Loc, Object.DebugLoc, "DILocation", *this))
710     return true;
711   PFS.MF.setVariableDbgInfo(DIVar, DIExpr, unsigned(FrameIdx), DILoc);
712   return false;
713 }
714 
715 bool MIRParserImpl::parseMDNode(PerFunctionMIParsingState &PFS,
716     MDNode *&Node, const yaml::StringValue &Source) {
717   if (Source.Value.empty())
718     return false;
719   SMDiagnostic Error;
720   if (llvm::parseMDNode(PFS, Node, Source.Value, Error))
721     return error(Error, Source.SourceRange);
722   return false;
723 }
724 
725 bool MIRParserImpl::initializeConstantPool(PerFunctionMIParsingState &PFS,
726     MachineConstantPool &ConstantPool, const yaml::MachineFunction &YamlMF) {
727   DenseMap<unsigned, unsigned> &ConstantPoolSlots = PFS.ConstantPoolSlots;
728   const MachineFunction &MF = PFS.MF;
729   const auto &M = *MF.getFunction().getParent();
730   SMDiagnostic Error;
731   for (const auto &YamlConstant : YamlMF.Constants) {
732     if (YamlConstant.IsTargetSpecific)
733       // FIXME: Support target-specific constant pools
734       return error(YamlConstant.Value.SourceRange.Start,
735                    "Can't parse target-specific constant pool entries yet");
736     const Constant *Value = dyn_cast_or_null<Constant>(
737         parseConstantValue(YamlConstant.Value.Value, Error, M));
738     if (!Value)
739       return error(Error, YamlConstant.Value.SourceRange);
740     unsigned Alignment =
741         YamlConstant.Alignment
742             ? YamlConstant.Alignment
743             : M.getDataLayout().getPrefTypeAlignment(Value->getType());
744     unsigned Index = ConstantPool.getConstantPoolIndex(Value, Alignment);
745     if (!ConstantPoolSlots.insert(std::make_pair(YamlConstant.ID.Value, Index))
746              .second)
747       return error(YamlConstant.ID.SourceRange.Start,
748                    Twine("redefinition of constant pool item '%const.") +
749                        Twine(YamlConstant.ID.Value) + "'");
750   }
751   return false;
752 }
753 
754 bool MIRParserImpl::initializeJumpTableInfo(PerFunctionMIParsingState &PFS,
755     const yaml::MachineJumpTable &YamlJTI) {
756   MachineJumpTableInfo *JTI = PFS.MF.getOrCreateJumpTableInfo(YamlJTI.Kind);
757   for (const auto &Entry : YamlJTI.Entries) {
758     std::vector<MachineBasicBlock *> Blocks;
759     for (const auto &MBBSource : Entry.Blocks) {
760       MachineBasicBlock *MBB = nullptr;
761       if (parseMBBReference(PFS, MBB, MBBSource.Value))
762         return true;
763       Blocks.push_back(MBB);
764     }
765     unsigned Index = JTI->createJumpTableIndex(Blocks);
766     if (!PFS.JumpTableSlots.insert(std::make_pair(Entry.ID.Value, Index))
767              .second)
768       return error(Entry.ID.SourceRange.Start,
769                    Twine("redefinition of jump table entry '%jump-table.") +
770                        Twine(Entry.ID.Value) + "'");
771   }
772   return false;
773 }
774 
775 bool MIRParserImpl::parseMBBReference(PerFunctionMIParsingState &PFS,
776                                       MachineBasicBlock *&MBB,
777                                       const yaml::StringValue &Source) {
778   SMDiagnostic Error;
779   if (llvm::parseMBBReference(PFS, MBB, Source.Value, Error))
780     return error(Error, Source.SourceRange);
781   return false;
782 }
783 
784 SMDiagnostic MIRParserImpl::diagFromMIStringDiag(const SMDiagnostic &Error,
785                                                  SMRange SourceRange) {
786   assert(SourceRange.isValid() && "Invalid source range");
787   SMLoc Loc = SourceRange.Start;
788   bool HasQuote = Loc.getPointer() < SourceRange.End.getPointer() &&
789                   *Loc.getPointer() == '\'';
790   // Translate the location of the error from the location in the MI string to
791   // the corresponding location in the MIR file.
792   Loc = Loc.getFromPointer(Loc.getPointer() + Error.getColumnNo() +
793                            (HasQuote ? 1 : 0));
794 
795   // TODO: Translate any source ranges as well.
796   return SM.GetMessage(Loc, Error.getKind(), Error.getMessage(), None,
797                        Error.getFixIts());
798 }
799 
800 SMDiagnostic MIRParserImpl::diagFromBlockStringDiag(const SMDiagnostic &Error,
801                                                     SMRange SourceRange) {
802   assert(SourceRange.isValid());
803 
804   // Translate the location of the error from the location in the llvm IR string
805   // to the corresponding location in the MIR file.
806   auto LineAndColumn = SM.getLineAndColumn(SourceRange.Start);
807   unsigned Line = LineAndColumn.first + Error.getLineNo() - 1;
808   unsigned Column = Error.getColumnNo();
809   StringRef LineStr = Error.getLineContents();
810   SMLoc Loc = Error.getLoc();
811 
812   // Get the full line and adjust the column number by taking the indentation of
813   // LLVM IR into account.
814   for (line_iterator L(*SM.getMemoryBuffer(SM.getMainFileID()), false), E;
815        L != E; ++L) {
816     if (L.line_number() == Line) {
817       LineStr = *L;
818       Loc = SMLoc::getFromPointer(LineStr.data());
819       auto Indent = LineStr.find(Error.getLineContents());
820       if (Indent != StringRef::npos)
821         Column += Indent;
822       break;
823     }
824   }
825 
826   return SMDiagnostic(SM, Loc, Filename, Line, Column, Error.getKind(),
827                       Error.getMessage(), LineStr, Error.getRanges(),
828                       Error.getFixIts());
829 }
830 
831 void MIRParserImpl::initNames2RegClasses(const MachineFunction &MF) {
832   if (!Names2RegClasses.empty())
833     return;
834   const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
835   for (unsigned I = 0, E = TRI->getNumRegClasses(); I < E; ++I) {
836     const auto *RC = TRI->getRegClass(I);
837     Names2RegClasses.insert(
838         std::make_pair(StringRef(TRI->getRegClassName(RC)).lower(), RC));
839   }
840 }
841 
842 void MIRParserImpl::initNames2RegBanks(const MachineFunction &MF) {
843   if (!Names2RegBanks.empty())
844     return;
845   const RegisterBankInfo *RBI = MF.getSubtarget().getRegBankInfo();
846   // If the target does not support GlobalISel, we may not have a
847   // register bank info.
848   if (!RBI)
849     return;
850   for (unsigned I = 0, E = RBI->getNumRegBanks(); I < E; ++I) {
851     const auto &RegBank = RBI->getRegBank(I);
852     Names2RegBanks.insert(
853         std::make_pair(StringRef(RegBank.getName()).lower(), &RegBank));
854   }
855 }
856 
857 const TargetRegisterClass *MIRParserImpl::getRegClass(const MachineFunction &MF,
858                                                       StringRef Name) {
859   auto RegClassInfo = Names2RegClasses.find(Name);
860   if (RegClassInfo == Names2RegClasses.end())
861     return nullptr;
862   return RegClassInfo->getValue();
863 }
864 
865 const RegisterBank *MIRParserImpl::getRegBank(const MachineFunction &MF,
866                                               StringRef Name) {
867   auto RegBankInfo = Names2RegBanks.find(Name);
868   if (RegBankInfo == Names2RegBanks.end())
869     return nullptr;
870   return RegBankInfo->getValue();
871 }
872 
873 MIRParser::MIRParser(std::unique_ptr<MIRParserImpl> Impl)
874     : Impl(std::move(Impl)) {}
875 
876 MIRParser::~MIRParser() {}
877 
878 std::unique_ptr<Module> MIRParser::parseIRModule() {
879   return Impl->parseIRModule();
880 }
881 
882 bool MIRParser::parseMachineFunctions(Module &M, MachineModuleInfo &MMI) {
883   return Impl->parseMachineFunctions(M, MMI);
884 }
885 
886 std::unique_ptr<MIRParser> llvm::createMIRParserFromFile(StringRef Filename,
887                                                          SMDiagnostic &Error,
888                                                          LLVMContext &Context) {
889   auto FileOrErr = MemoryBuffer::getFileOrSTDIN(Filename);
890   if (std::error_code EC = FileOrErr.getError()) {
891     Error = SMDiagnostic(Filename, SourceMgr::DK_Error,
892                          "Could not open input file: " + EC.message());
893     return nullptr;
894   }
895   return createMIRParser(std::move(FileOrErr.get()), Context);
896 }
897 
898 std::unique_ptr<MIRParser>
899 llvm::createMIRParser(std::unique_ptr<MemoryBuffer> Contents,
900                       LLVMContext &Context) {
901   auto Filename = Contents->getBufferIdentifier();
902   if (Context.shouldDiscardValueNames()) {
903     Context.diagnose(DiagnosticInfoMIRParser(
904         DS_Error,
905         SMDiagnostic(
906             Filename, SourceMgr::DK_Error,
907             "Can't read MIR with a Context that discards named Values")));
908     return nullptr;
909   }
910   return llvm::make_unique<MIRParser>(
911       llvm::make_unique<MIRParserImpl>(std::move(Contents), Filename, Context));
912 }
913