BitcodeReader.cpp revision 5cb1f3949c5bdd43c84647920d147a6b8509e256 
1//===- BitcodeReader.cpp - Internal BitcodeReader 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 header defines the BitcodeReader class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Bitcode/ReaderWriter.h"
15#include "BitReader_2_7.h"
16#include "llvm/ADT/STLExtras.h"
17#include "llvm/ADT/SmallString.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/IR/AutoUpgrade.h"
20#include "llvm/IR/Constants.h"
21#include "llvm/IR/DerivedTypes.h"
22#include "llvm/IR/DiagnosticPrinter.h"
23#include "llvm/IR/GVMaterializer.h"
24#include "llvm/IR/InlineAsm.h"
25#include "llvm/IR/IntrinsicInst.h"
26#include "llvm/IR/LLVMContext.h"
27#include "llvm/IR/Module.h"
28#include "llvm/IR/OperandTraits.h"
29#include "llvm/IR/Operator.h"
30#include "llvm/Support/ManagedStatic.h"
31#include "llvm/Support/MathExtras.h"
32#include "llvm/Support/MemoryBuffer.h"
33
34using namespace llvm;
35using namespace llvm_2_7;
36
37#define METADATA_NODE_2_7             2
38#define METADATA_FN_NODE_2_7          3
39#define METADATA_NAMED_NODE_2_7       5
40#define METADATA_ATTACHMENT_2_7       7
41#define FUNC_CODE_INST_UNWIND_2_7     14
42#define FUNC_CODE_INST_MALLOC_2_7     17
43#define FUNC_CODE_INST_FREE_2_7       18
44#define FUNC_CODE_INST_STORE_2_7      21
45#define FUNC_CODE_INST_CALL_2_7       22
46#define FUNC_CODE_INST_GETRESULT_2_7  25
47#define FUNC_CODE_DEBUG_LOC_2_7       32
48
49#define TYPE_BLOCK_ID_OLD_3_0         10
50#define TYPE_SYMTAB_BLOCK_ID_OLD_3_0  13
51#define TYPE_CODE_STRUCT_OLD_3_0      10
52
53namespace {
54
55  void StripDebugInfoOfFunction(Module* M, const char* name) {
56    if (Function* FuncStart = M->getFunction(name)) {
57      while (!FuncStart->use_empty()) {
58        cast<CallInst>(*FuncStart->use_begin())->eraseFromParent();
59      }
60      FuncStart->eraseFromParent();
61    }
62  }
63
64  /// This function strips all debug info intrinsics, except for llvm.dbg.declare.
65  /// If an llvm.dbg.declare intrinsic is invalid, then this function simply
66  /// strips that use.
67  void CheckDebugInfoIntrinsics(Module *M) {
68    StripDebugInfoOfFunction(M, "llvm.dbg.func.start");
69    StripDebugInfoOfFunction(M, "llvm.dbg.stoppoint");
70    StripDebugInfoOfFunction(M, "llvm.dbg.region.start");
71    StripDebugInfoOfFunction(M, "llvm.dbg.region.end");
72
73    if (Function *Declare = M->getFunction("llvm.dbg.declare")) {
74      if (!Declare->use_empty()) {
75        DbgDeclareInst *DDI = cast<DbgDeclareInst>(*Declare->use_begin());
76        if (!isa<MDNode>(ValueAsMetadata::get(DDI->getArgOperand(0))) ||
77            !isa<MDNode>(ValueAsMetadata::get(DDI->getArgOperand(1)))) {
78          while (!Declare->use_empty()) {
79            CallInst *CI = cast<CallInst>(*Declare->use_begin());
80            CI->eraseFromParent();
81          }
82          Declare->eraseFromParent();
83        }
84      }
85    }
86  }
87
88//===----------------------------------------------------------------------===//
89//                          BitcodeReaderValueList Class
90//===----------------------------------------------------------------------===//
91
92class BitcodeReaderValueList {
93  std::vector<WeakVH> ValuePtrs;
94
95  /// ResolveConstants - As we resolve forward-referenced constants, we add
96  /// information about them to this vector.  This allows us to resolve them in
97  /// bulk instead of resolving each reference at a time.  See the code in
98  /// ResolveConstantForwardRefs for more information about this.
99  ///
100  /// The key of this vector is the placeholder constant, the value is the slot
101  /// number that holds the resolved value.
102  typedef std::vector<std::pair<Constant*, unsigned> > ResolveConstantsTy;
103  ResolveConstantsTy ResolveConstants;
104  LLVMContext &Context;
105public:
106  BitcodeReaderValueList(LLVMContext &C) : Context(C) {}
107  ~BitcodeReaderValueList() {
108    assert(ResolveConstants.empty() && "Constants not resolved?");
109  }
110
111  // vector compatibility methods
112  unsigned size() const { return ValuePtrs.size(); }
113  void resize(unsigned N) { ValuePtrs.resize(N); }
114  void push_back(Value *V) {
115    ValuePtrs.push_back(V);
116  }
117
118  void clear() {
119    assert(ResolveConstants.empty() && "Constants not resolved?");
120    ValuePtrs.clear();
121  }
122
123  Value *operator[](unsigned i) const {
124    assert(i < ValuePtrs.size());
125    return ValuePtrs[i];
126  }
127
128  Value *back() const { return ValuePtrs.back(); }
129    void pop_back() { ValuePtrs.pop_back(); }
130  bool empty() const { return ValuePtrs.empty(); }
131  void shrinkTo(unsigned N) {
132    assert(N <= size() && "Invalid shrinkTo request!");
133    ValuePtrs.resize(N);
134  }
135
136  Constant *getConstantFwdRef(unsigned Idx, Type *Ty);
137  Value *getValueFwdRef(unsigned Idx, Type *Ty);
138
139  void AssignValue(Value *V, unsigned Idx);
140
141  /// ResolveConstantForwardRefs - Once all constants are read, this method bulk
142  /// resolves any forward references.
143  void ResolveConstantForwardRefs();
144};
145
146
147//===----------------------------------------------------------------------===//
148//                          BitcodeReaderMDValueList Class
149//===----------------------------------------------------------------------===//
150
151class BitcodeReaderMDValueList {
152  unsigned NumFwdRefs;
153  bool AnyFwdRefs;
154  std::vector<TrackingMDRef> MDValuePtrs;
155
156  LLVMContext &Context;
157public:
158  BitcodeReaderMDValueList(LLVMContext &C)
159      : NumFwdRefs(0), AnyFwdRefs(false), Context(C) {}
160
161  // vector compatibility methods
162  unsigned size() const       { return MDValuePtrs.size(); }
163  void resize(unsigned N)     { MDValuePtrs.resize(N); }
164  void push_back(Metadata *MD) { MDValuePtrs.emplace_back(MD); }
165  void clear()                { MDValuePtrs.clear();  }
166  Metadata *back() const      { return MDValuePtrs.back(); }
167  void pop_back()             { MDValuePtrs.pop_back(); }
168  bool empty() const          { return MDValuePtrs.empty(); }
169
170  Metadata *operator[](unsigned i) const {
171    assert(i < MDValuePtrs.size());
172    return MDValuePtrs[i];
173  }
174
175  void shrinkTo(unsigned N) {
176    assert(N <= size() && "Invalid shrinkTo request!");
177    MDValuePtrs.resize(N);
178  }
179
180  Metadata *getValueFwdRef(unsigned Idx);
181  void AssignValue(Metadata *MD, unsigned Idx);
182  void tryToResolveCycles();
183};
184
185class BitcodeReader : public GVMaterializer {
186  LLVMContext &Context;
187  DiagnosticHandlerFunction DiagnosticHandler;
188  Module *TheModule;
189  std::unique_ptr<MemoryBuffer> Buffer;
190  std::unique_ptr<BitstreamReader> StreamFile;
191  BitstreamCursor Stream;
192  DataStreamer *LazyStreamer;
193  uint64_t NextUnreadBit;
194  bool SeenValueSymbolTable;
195
196  std::vector<Type*> TypeList;
197  BitcodeReaderValueList ValueList;
198  BitcodeReaderMDValueList MDValueList;
199  SmallVector<Instruction *, 64> InstructionList;
200
201  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits;
202  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInits;
203
204  /// MAttributes - The set of attributes by index.  Index zero in the
205  /// file is for null, and is thus not represented here.  As such all indices
206  /// are off by one.
207  std::vector<AttributeSet> MAttributes;
208
209  /// \brief The set of attribute groups.
210  std::map<unsigned, AttributeSet> MAttributeGroups;
211
212  /// FunctionBBs - While parsing a function body, this is a list of the basic
213  /// blocks for the function.
214  std::vector<BasicBlock*> FunctionBBs;
215
216  // When reading the module header, this list is populated with functions that
217  // have bodies later in the file.
218  std::vector<Function*> FunctionsWithBodies;
219
220  // When intrinsic functions are encountered which require upgrading they are
221  // stored here with their replacement function.
222  typedef std::vector<std::pair<Function*, Function*> > UpgradedIntrinsicMap;
223  UpgradedIntrinsicMap UpgradedIntrinsics;
224
225  // Map the bitcode's custom MDKind ID to the Module's MDKind ID.
226  DenseMap<unsigned, unsigned> MDKindMap;
227
228  // Several operations happen after the module header has been read, but
229  // before function bodies are processed. This keeps track of whether
230  // we've done this yet.
231  bool SeenFirstFunctionBody;
232
233  /// DeferredFunctionInfo - When function bodies are initially scanned, this
234  /// map contains info about where to find deferred function body in the
235  /// stream.
236  DenseMap<Function*, uint64_t> DeferredFunctionInfo;
237
238  /// BlockAddrFwdRefs - These are blockaddr references to basic blocks.  These
239  /// are resolved lazily when functions are loaded.
240  typedef std::pair<unsigned, GlobalVariable*> BlockAddrRefTy;
241  DenseMap<Function*, std::vector<BlockAddrRefTy> > BlockAddrFwdRefs;
242
243  /// LLVM2_7MetadataDetected - True if metadata produced by LLVM 2.7 or
244  /// earlier was detected, in which case we behave slightly differently,
245  /// for compatibility.
246  /// FIXME: Remove in LLVM 3.0.
247  bool LLVM2_7MetadataDetected;
248  static const std::error_category &BitcodeErrorCategory();
249
250public:
251  std::error_code Error(BitcodeError E, const Twine &Message);
252  std::error_code Error(BitcodeError E);
253  std::error_code Error(const Twine &Message);
254
255  explicit BitcodeReader(MemoryBuffer *buffer, LLVMContext &C,
256                         DiagnosticHandlerFunction DiagnosticHandler);
257  ~BitcodeReader() { FreeState(); }
258
259  void FreeState();
260
261  void releaseBuffer();
262
263  bool isDematerializable(const GlobalValue *GV) const override;
264  std::error_code materialize(GlobalValue *GV) override;
265  std::error_code MaterializeModule(Module *M) override;
266  std::vector<StructType *> getIdentifiedStructTypes() const override;
267  void Dematerialize(GlobalValue *GV) override;
268
269  /// @brief Main interface to parsing a bitcode buffer.
270  /// @returns true if an error occurred.
271  std::error_code ParseBitcodeInto(Module *M);
272
273  /// @brief Cheap mechanism to just extract module triple
274  /// @returns true if an error occurred.
275  llvm::ErrorOr<std::string> parseTriple();
276
277  static uint64_t decodeSignRotatedValue(uint64_t V);
278
279  /// Materialize any deferred Metadata block.
280  std::error_code materializeMetadata() override;
281
282private:
283  std::vector<StructType *> IdentifiedStructTypes;
284  StructType *createIdentifiedStructType(LLVMContext &Context, StringRef Name);
285  StructType *createIdentifiedStructType(LLVMContext &Context);
286
287  Type *getTypeByID(unsigned ID);
288  Type *getTypeByIDOrNull(unsigned ID);
289  Value *getFnValueByID(unsigned ID, Type *Ty) {
290    if (Ty && Ty->isMetadataTy())
291      return MetadataAsValue::get(Ty->getContext(), getFnMetadataByID(ID));
292    return ValueList.getValueFwdRef(ID, Ty);
293  }
294  Metadata *getFnMetadataByID(unsigned ID) {
295    return MDValueList.getValueFwdRef(ID);
296  }
297  BasicBlock *getBasicBlock(unsigned ID) const {
298    if (ID >= FunctionBBs.size()) return nullptr; // Invalid ID
299    return FunctionBBs[ID];
300  }
301  AttributeSet getAttributes(unsigned i) const {
302    if (i-1 < MAttributes.size())
303      return MAttributes[i-1];
304    return AttributeSet();
305  }
306
307  /// getValueTypePair - Read a value/type pair out of the specified record from
308  /// slot 'Slot'.  Increment Slot past the number of slots used in the record.
309  /// Return true on failure.
310  bool getValueTypePair(SmallVectorImpl<uint64_t> &Record, unsigned &Slot,
311                        unsigned InstNum, Value *&ResVal) {
312    if (Slot == Record.size()) return true;
313    unsigned ValNo = (unsigned)Record[Slot++];
314    if (ValNo < InstNum) {
315      // If this is not a forward reference, just return the value we already
316      // have.
317      ResVal = getFnValueByID(ValNo, nullptr);
318      return ResVal == nullptr;
319    } else if (Slot == Record.size()) {
320      return true;
321    }
322
323    unsigned TypeNo = (unsigned)Record[Slot++];
324    ResVal = getFnValueByID(ValNo, getTypeByID(TypeNo));
325    return ResVal == nullptr;
326  }
327  bool getValue(SmallVector<uint64_t, 64> &Record, unsigned &Slot,
328                Type *Ty, Value *&ResVal) {
329    if (Slot == Record.size()) return true;
330    unsigned ValNo = (unsigned)Record[Slot++];
331    ResVal = getFnValueByID(ValNo, Ty);
332    return ResVal == 0;
333  }
334
335
336  std::error_code ParseModule(bool Resume);
337  std::error_code ParseAttributeBlock();
338  std::error_code ParseTypeTable();
339  std::error_code ParseOldTypeTable();         // FIXME: Remove in LLVM 3.1
340  std::error_code ParseTypeTableBody();
341
342  std::error_code ParseOldTypeSymbolTable();   // FIXME: Remove in LLVM 3.1
343  std::error_code ParseValueSymbolTable();
344  std::error_code ParseConstants();
345  std::error_code RememberAndSkipFunctionBody();
346  std::error_code ParseFunctionBody(Function *F);
347  std::error_code GlobalCleanup();
348  std::error_code ResolveGlobalAndAliasInits();
349  std::error_code ParseMetadata();
350  std::error_code ParseMetadataAttachment();
351  llvm::ErrorOr<std::string> parseModuleTriple();
352  std::error_code InitStream();
353  std::error_code InitStreamFromBuffer();
354  std::error_code InitLazyStream();
355};
356} // end anonymous namespace
357
358static std::error_code Error(DiagnosticHandlerFunction DiagnosticHandler,
359                             std::error_code EC, const Twine &Message) {
360  BitcodeDiagnosticInfo DI(EC, DS_Error, Message);
361  DiagnosticHandler(DI);
362  return EC;
363}
364
365static std::error_code Error(DiagnosticHandlerFunction DiagnosticHandler,
366                             std::error_code EC) {
367  return Error(DiagnosticHandler, EC, EC.message());
368}
369
370std::error_code BitcodeReader::Error(BitcodeError E, const Twine &Message) {
371  return ::Error(DiagnosticHandler, make_error_code(E), Message);
372}
373
374std::error_code BitcodeReader::Error(const Twine &Message) {
375  return ::Error(DiagnosticHandler,
376                 make_error_code(BitcodeError::CorruptedBitcode), Message);
377}
378
379std::error_code BitcodeReader::Error(BitcodeError E) {
380  return ::Error(DiagnosticHandler, make_error_code(E));
381}
382
383static DiagnosticHandlerFunction getDiagHandler(DiagnosticHandlerFunction F,
384                                                LLVMContext &C) {
385  if (F)
386    return F;
387  return [&C](const DiagnosticInfo &DI) { C.diagnose(DI); };
388}
389
390BitcodeReader::BitcodeReader(MemoryBuffer *buffer, LLVMContext &C,
391                             DiagnosticHandlerFunction DiagnosticHandler)
392    : Context(C), DiagnosticHandler(getDiagHandler(DiagnosticHandler, C)),
393      TheModule(nullptr), Buffer(buffer), LazyStreamer(nullptr),
394      NextUnreadBit(0), SeenValueSymbolTable(false), ValueList(C),
395      MDValueList(C), SeenFirstFunctionBody(false),
396      LLVM2_7MetadataDetected(false) {}
397
398
399void BitcodeReader::FreeState() {
400  Buffer = nullptr;
401  std::vector<Type*>().swap(TypeList);
402  ValueList.clear();
403  MDValueList.clear();
404
405  std::vector<AttributeSet>().swap(MAttributes);
406  std::vector<BasicBlock*>().swap(FunctionBBs);
407  std::vector<Function*>().swap(FunctionsWithBodies);
408  DeferredFunctionInfo.clear();
409  MDKindMap.clear();
410}
411
412//===----------------------------------------------------------------------===//
413//  Helper functions to implement forward reference resolution, etc.
414//===----------------------------------------------------------------------===//
415
416/// ConvertToString - Convert a string from a record into an std::string, return
417/// true on failure.
418template<typename StrTy>
419static bool ConvertToString(ArrayRef<uint64_t> Record, unsigned Idx,
420                            StrTy &Result) {
421  if (Idx > Record.size())
422    return true;
423
424  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
425    Result += (char)Record[i];
426  return false;
427}
428
429static GlobalValue::LinkageTypes getDecodedLinkage(unsigned Val) {
430  switch (Val) {
431  default: // Map unknown/new linkages to external
432  case 0:
433    return GlobalValue::ExternalLinkage;
434  case 1:
435    return GlobalValue::WeakAnyLinkage;
436  case 2:
437    return GlobalValue::AppendingLinkage;
438  case 3:
439    return GlobalValue::InternalLinkage;
440  case 4:
441    return GlobalValue::LinkOnceAnyLinkage;
442  case 5:
443    return GlobalValue::ExternalLinkage; // Obsolete DLLImportLinkage
444  case 6:
445    return GlobalValue::ExternalLinkage; // Obsolete DLLExportLinkage
446  case 7:
447    return GlobalValue::ExternalWeakLinkage;
448  case 8:
449    return GlobalValue::CommonLinkage;
450  case 9:
451    return GlobalValue::PrivateLinkage;
452  case 10:
453    return GlobalValue::WeakODRLinkage;
454  case 11:
455    return GlobalValue::LinkOnceODRLinkage;
456  case 12:
457    return GlobalValue::AvailableExternallyLinkage;
458  case 13:
459    return GlobalValue::PrivateLinkage; // Obsolete LinkerPrivateLinkage
460  case 14:
461    return GlobalValue::ExternalWeakLinkage; // Obsolete LinkerPrivateWeakLinkage
462  //ANDROID: convert LinkOnceODRAutoHideLinkage -> LinkOnceODRLinkage
463  case 15:
464    return GlobalValue::LinkOnceODRLinkage;
465  }
466}
467
468static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
469  switch (Val) {
470  default: // Map unknown visibilities to default.
471  case 0: return GlobalValue::DefaultVisibility;
472  case 1: return GlobalValue::HiddenVisibility;
473  case 2: return GlobalValue::ProtectedVisibility;
474  }
475}
476
477static GlobalVariable::ThreadLocalMode GetDecodedThreadLocalMode(unsigned Val) {
478  switch (Val) {
479    case 0: return GlobalVariable::NotThreadLocal;
480    default: // Map unknown non-zero value to general dynamic.
481    case 1: return GlobalVariable::GeneralDynamicTLSModel;
482    case 2: return GlobalVariable::LocalDynamicTLSModel;
483    case 3: return GlobalVariable::InitialExecTLSModel;
484    case 4: return GlobalVariable::LocalExecTLSModel;
485  }
486}
487
488static int GetDecodedCastOpcode(unsigned Val) {
489  switch (Val) {
490  default: return -1;
491  case bitc::CAST_TRUNC   : return Instruction::Trunc;
492  case bitc::CAST_ZEXT    : return Instruction::ZExt;
493  case bitc::CAST_SEXT    : return Instruction::SExt;
494  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
495  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
496  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
497  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
498  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
499  case bitc::CAST_FPEXT   : return Instruction::FPExt;
500  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
501  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
502  case bitc::CAST_BITCAST : return Instruction::BitCast;
503  }
504}
505static int GetDecodedBinaryOpcode(unsigned Val, Type *Ty) {
506  switch (Val) {
507  default: return -1;
508  case bitc::BINOP_ADD:
509    return Ty->isFPOrFPVectorTy() ? Instruction::FAdd : Instruction::Add;
510  case bitc::BINOP_SUB:
511    return Ty->isFPOrFPVectorTy() ? Instruction::FSub : Instruction::Sub;
512  case bitc::BINOP_MUL:
513    return Ty->isFPOrFPVectorTy() ? Instruction::FMul : Instruction::Mul;
514  case bitc::BINOP_UDIV: return Instruction::UDiv;
515  case bitc::BINOP_SDIV:
516    return Ty->isFPOrFPVectorTy() ? Instruction::FDiv : Instruction::SDiv;
517  case bitc::BINOP_UREM: return Instruction::URem;
518  case bitc::BINOP_SREM:
519    return Ty->isFPOrFPVectorTy() ? Instruction::FRem : Instruction::SRem;
520  case bitc::BINOP_SHL:  return Instruction::Shl;
521  case bitc::BINOP_LSHR: return Instruction::LShr;
522  case bitc::BINOP_ASHR: return Instruction::AShr;
523  case bitc::BINOP_AND:  return Instruction::And;
524  case bitc::BINOP_OR:   return Instruction::Or;
525  case bitc::BINOP_XOR:  return Instruction::Xor;
526  }
527}
528
529namespace llvm {
530namespace {
531  /// @brief A class for maintaining the slot number definition
532  /// as a placeholder for the actual definition for forward constants defs.
533  class ConstantPlaceHolder : public ConstantExpr {
534    void operator=(const ConstantPlaceHolder &) = delete;
535  public:
536    // allocate space for exactly one operand
537    void *operator new(size_t s) {
538      return User::operator new(s, 1);
539    }
540    explicit ConstantPlaceHolder(Type *Ty, LLVMContext& Context)
541      : ConstantExpr(Ty, Instruction::UserOp1, &Op<0>(), 1) {
542      Op<0>() = UndefValue::get(Type::getInt32Ty(Context));
543    }
544
545    /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
546    static bool classof(const Value *V) {
547      return isa<ConstantExpr>(V) &&
548             cast<ConstantExpr>(V)->getOpcode() == Instruction::UserOp1;
549    }
550
551
552    /// Provide fast operand accessors
553    DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
554  };
555}
556
557// FIXME: can we inherit this from ConstantExpr?
558template <>
559struct OperandTraits<ConstantPlaceHolder> :
560  public FixedNumOperandTraits<ConstantPlaceHolder, 1> {
561};
562DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantPlaceHolder, Value)
563}
564
565
566void BitcodeReaderValueList::AssignValue(Value *V, unsigned Idx) {
567  if (Idx == size()) {
568    push_back(V);
569    return;
570  }
571
572  if (Idx >= size())
573    resize(Idx+1);
574
575  WeakVH &OldV = ValuePtrs[Idx];
576  if (!OldV) {
577    OldV = V;
578    return;
579  }
580
581  // Handle constants and non-constants (e.g. instrs) differently for
582  // efficiency.
583  if (Constant *PHC = dyn_cast<Constant>(&*OldV)) {
584    ResolveConstants.push_back(std::make_pair(PHC, Idx));
585    OldV = V;
586  } else {
587    // If there was a forward reference to this value, replace it.
588    Value *PrevVal = OldV;
589    OldV->replaceAllUsesWith(V);
590    delete PrevVal;
591  }
592}
593
594
595Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
596                                                    Type *Ty) {
597  if (Idx >= size())
598    resize(Idx + 1);
599
600  if (Value *V = ValuePtrs[Idx]) {
601    assert(Ty == V->getType() && "Type mismatch in constant table!");
602    return cast<Constant>(V);
603  }
604
605  // Create and return a placeholder, which will later be RAUW'd.
606  Constant *C = new ConstantPlaceHolder(Ty, Context);
607  ValuePtrs[Idx] = C;
608  return C;
609}
610
611Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, Type *Ty) {
612  if (Idx >= size())
613    resize(Idx + 1);
614
615  if (Value *V = ValuePtrs[Idx]) {
616    assert((!Ty || Ty == V->getType()) && "Type mismatch in value table!");
617    return V;
618  }
619
620  // No type specified, must be invalid reference.
621  if (!Ty) return nullptr;
622
623  // Create and return a placeholder, which will later be RAUW'd.
624  Value *V = new Argument(Ty);
625  ValuePtrs[Idx] = V;
626  return V;
627}
628
629/// ResolveConstantForwardRefs - Once all constants are read, this method bulk
630/// resolves any forward references.  The idea behind this is that we sometimes
631/// get constants (such as large arrays) which reference *many* forward ref
632/// constants.  Replacing each of these causes a lot of thrashing when
633/// building/reuniquing the constant.  Instead of doing this, we look at all the
634/// uses and rewrite all the place holders at once for any constant that uses
635/// a placeholder.
636void BitcodeReaderValueList::ResolveConstantForwardRefs() {
637  // Sort the values by-pointer so that they are efficient to look up with a
638  // binary search.
639  std::sort(ResolveConstants.begin(), ResolveConstants.end());
640
641  SmallVector<Constant*, 64> NewOps;
642
643  while (!ResolveConstants.empty()) {
644    Value *RealVal = operator[](ResolveConstants.back().second);
645    Constant *Placeholder = ResolveConstants.back().first;
646    ResolveConstants.pop_back();
647
648    // Loop over all users of the placeholder, updating them to reference the
649    // new value.  If they reference more than one placeholder, update them all
650    // at once.
651    while (!Placeholder->use_empty()) {
652      auto UI = Placeholder->user_begin();
653      User *U = *UI;
654
655      // If the using object isn't uniqued, just update the operands.  This
656      // handles instructions and initializers for global variables.
657      if (!isa<Constant>(U) || isa<GlobalValue>(U)) {
658        UI.getUse().set(RealVal);
659        continue;
660      }
661
662      // Otherwise, we have a constant that uses the placeholder.  Replace that
663      // constant with a new constant that has *all* placeholder uses updated.
664      Constant *UserC = cast<Constant>(U);
665      for (User::op_iterator I = UserC->op_begin(), E = UserC->op_end();
666           I != E; ++I) {
667        Value *NewOp;
668        if (!isa<ConstantPlaceHolder>(*I)) {
669          // Not a placeholder reference.
670          NewOp = *I;
671        } else if (*I == Placeholder) {
672          // Common case is that it just references this one placeholder.
673          NewOp = RealVal;
674        } else {
675          // Otherwise, look up the placeholder in ResolveConstants.
676          ResolveConstantsTy::iterator It =
677            std::lower_bound(ResolveConstants.begin(), ResolveConstants.end(),
678                             std::pair<Constant*, unsigned>(cast<Constant>(*I),
679                                                            0));
680          assert(It != ResolveConstants.end() && It->first == *I);
681          NewOp = operator[](It->second);
682        }
683
684        NewOps.push_back(cast<Constant>(NewOp));
685      }
686
687      // Make the new constant.
688      Constant *NewC;
689      if (ConstantArray *UserCA = dyn_cast<ConstantArray>(UserC)) {
690        NewC = ConstantArray::get(UserCA->getType(), NewOps);
691      } else if (ConstantStruct *UserCS = dyn_cast<ConstantStruct>(UserC)) {
692        NewC = ConstantStruct::get(UserCS->getType(), NewOps);
693      } else if (isa<ConstantVector>(UserC)) {
694        NewC = ConstantVector::get(NewOps);
695      } else {
696        assert(isa<ConstantExpr>(UserC) && "Must be a ConstantExpr.");
697        NewC = cast<ConstantExpr>(UserC)->getWithOperands(NewOps);
698      }
699
700      UserC->replaceAllUsesWith(NewC);
701      UserC->destroyConstant();
702      NewOps.clear();
703    }
704
705    // Update all ValueHandles, they should be the only users at this point.
706    Placeholder->replaceAllUsesWith(RealVal);
707    delete Placeholder;
708  }
709}
710
711void BitcodeReaderMDValueList::AssignValue(Metadata *MD, unsigned Idx) {
712  if (Idx == size()) {
713    push_back(MD);
714    return;
715  }
716
717  if (Idx >= size())
718    resize(Idx+1);
719
720  TrackingMDRef &OldMD = MDValuePtrs[Idx];
721  if (!OldMD) {
722    OldMD.reset(MD);
723    return;
724  }
725
726  // If there was a forward reference to this value, replace it.
727  TempMDTuple PrevMD(cast<MDTuple>(OldMD.get()));
728  PrevMD->replaceAllUsesWith(MD);
729  --NumFwdRefs;
730}
731
732Metadata *BitcodeReaderMDValueList::getValueFwdRef(unsigned Idx) {
733  if (Idx >= size())
734    resize(Idx + 1);
735
736  if (Metadata *MD = MDValuePtrs[Idx])
737    return MD;
738
739  // Create and return a placeholder, which will later be RAUW'd.
740  AnyFwdRefs = true;
741  ++NumFwdRefs;
742  Metadata *MD = MDNode::getTemporary(Context, None).release();
743  MDValuePtrs[Idx].reset(MD);
744  return MD;
745}
746
747void BitcodeReaderMDValueList::tryToResolveCycles() {
748  if (!AnyFwdRefs)
749    // Nothing to do.
750    return;
751
752  if (NumFwdRefs)
753    // Still forward references... can't resolve cycles.
754    return;
755
756  // Resolve any cycles.
757  for (auto &MD : MDValuePtrs) {
758    auto *N = dyn_cast_or_null<MDNode>(MD);
759    if (!N)
760      continue;
761
762    assert(!N->isTemporary() && "Unexpected forward reference");
763    N->resolveCycles();
764  }
765}
766
767Type *BitcodeReader::getTypeByID(unsigned ID) {
768  // The type table size is always specified correctly.
769  if (ID >= TypeList.size())
770    return nullptr;
771
772  if (Type *Ty = TypeList[ID])
773    return Ty;
774
775  // If we have a forward reference, the only possible case is when it is to a
776  // named struct.  Just create a placeholder for now.
777  return TypeList[ID] = createIdentifiedStructType(Context);
778}
779
780StructType *BitcodeReader::createIdentifiedStructType(LLVMContext &Context,
781                                                      StringRef Name) {
782  auto *Ret = StructType::create(Context, Name);
783  IdentifiedStructTypes.push_back(Ret);
784  return Ret;
785}
786
787StructType *BitcodeReader::createIdentifiedStructType(LLVMContext &Context) {
788  auto *Ret = StructType::create(Context);
789  IdentifiedStructTypes.push_back(Ret);
790  return Ret;
791}
792
793
794/// FIXME: Remove in LLVM 3.1, only used by ParseOldTypeTable.
795Type *BitcodeReader::getTypeByIDOrNull(unsigned ID) {
796  if (ID >= TypeList.size())
797    TypeList.resize(ID+1);
798
799  return TypeList[ID];
800}
801
802//===----------------------------------------------------------------------===//
803//  Functions for parsing blocks from the bitcode file
804//===----------------------------------------------------------------------===//
805
806
807/// \brief This fills an AttrBuilder object with the LLVM attributes that have
808/// been decoded from the given integer. This function must stay in sync with
809/// 'encodeLLVMAttributesForBitcode'.
810static void decodeLLVMAttributesForBitcode(AttrBuilder &B,
811                                           uint64_t EncodedAttrs) {
812  // FIXME: Remove in 4.0.
813
814  // The alignment is stored as a 16-bit raw value from bits 31--16.  We shift
815  // the bits above 31 down by 11 bits.
816  unsigned Alignment = (EncodedAttrs & (0xffffULL << 16)) >> 16;
817  assert((!Alignment || isPowerOf2_32(Alignment)) &&
818         "Alignment must be a power of two.");
819
820  if (Alignment)
821    B.addAlignmentAttr(Alignment);
822  B.addRawValue(((EncodedAttrs & (0xfffffULL << 32)) >> 11) |
823                (EncodedAttrs & 0xffff));
824}
825
826std::error_code BitcodeReader::ParseAttributeBlock() {
827  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
828    return Error("Invalid record");
829
830  if (!MAttributes.empty())
831    return Error("Invalid multiple blocks");
832
833  SmallVector<uint64_t, 64> Record;
834
835  SmallVector<AttributeSet, 8> Attrs;
836
837  // Read all the records.
838  while (1) {
839    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
840
841    switch (Entry.Kind) {
842    case BitstreamEntry::SubBlock: // Handled for us already.
843    case BitstreamEntry::Error:
844      return Error("Malformed block");
845    case BitstreamEntry::EndBlock:
846      return std::error_code();
847    case BitstreamEntry::Record:
848      // The interesting case.
849      break;
850    }
851
852    // Read a record.
853    Record.clear();
854    switch (Stream.readRecord(Entry.ID, Record)) {
855    default:  // Default behavior: ignore.
856      break;
857    case bitc::PARAMATTR_CODE_ENTRY_OLD: { // ENTRY: [paramidx0, attr0, ...]
858      if (Record.size() & 1)
859        return Error("Invalid record");
860
861      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
862        AttrBuilder B;
863        decodeLLVMAttributesForBitcode(B, Record[i+1]);
864        Attrs.push_back(AttributeSet::get(Context, Record[i], B));
865      }
866
867      MAttributes.push_back(AttributeSet::get(Context, Attrs));
868      Attrs.clear();
869      break;
870    }
871    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [attrgrp0, attrgrp1, ...]
872      for (unsigned i = 0, e = Record.size(); i != e; ++i)
873        Attrs.push_back(MAttributeGroups[Record[i]]);
874
875      MAttributes.push_back(AttributeSet::get(Context, Attrs));
876      Attrs.clear();
877      break;
878    }
879    }
880  }
881}
882
883
884std::error_code BitcodeReader::ParseTypeTable() {
885  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID_NEW))
886    return Error("Invalid record");
887
888  return ParseTypeTableBody();
889}
890
891std::error_code BitcodeReader::ParseTypeTableBody() {
892  if (!TypeList.empty())
893    return Error("Invalid multiple blocks");
894
895  SmallVector<uint64_t, 64> Record;
896  unsigned NumRecords = 0;
897
898  SmallString<64> TypeName;
899
900  // Read all the records for this type table.
901  while (1) {
902    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
903
904    switch (Entry.Kind) {
905    case BitstreamEntry::SubBlock: // Handled for us already.
906    case BitstreamEntry::Error:
907      return Error("Malformed block");
908    case BitstreamEntry::EndBlock:
909      if (NumRecords != TypeList.size())
910        return Error("Malformed block");
911      return std::error_code();
912    case BitstreamEntry::Record:
913      // The interesting case.
914      break;
915    }
916
917    // Read a record.
918    Record.clear();
919    Type *ResultTy = nullptr;
920    switch (Stream.readRecord(Entry.ID, Record)) {
921    default:
922      return Error("Invalid value");
923    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
924      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
925      // type list.  This allows us to reserve space.
926      if (Record.size() < 1)
927        return Error("Invalid record");
928      TypeList.resize(Record[0]);
929      continue;
930    case bitc::TYPE_CODE_VOID:      // VOID
931      ResultTy = Type::getVoidTy(Context);
932      break;
933    case bitc::TYPE_CODE_HALF:     // HALF
934      ResultTy = Type::getHalfTy(Context);
935      break;
936    case bitc::TYPE_CODE_FLOAT:     // FLOAT
937      ResultTy = Type::getFloatTy(Context);
938      break;
939    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
940      ResultTy = Type::getDoubleTy(Context);
941      break;
942    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
943      ResultTy = Type::getX86_FP80Ty(Context);
944      break;
945    case bitc::TYPE_CODE_FP128:     // FP128
946      ResultTy = Type::getFP128Ty(Context);
947      break;
948    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
949      ResultTy = Type::getPPC_FP128Ty(Context);
950      break;
951    case bitc::TYPE_CODE_LABEL:     // LABEL
952      ResultTy = Type::getLabelTy(Context);
953      break;
954    case bitc::TYPE_CODE_METADATA:  // METADATA
955      ResultTy = Type::getMetadataTy(Context);
956      break;
957    case bitc::TYPE_CODE_X86_MMX:   // X86_MMX
958      ResultTy = Type::getX86_MMXTy(Context);
959      break;
960    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
961      if (Record.size() < 1)
962        return Error("Invalid record");
963
964      ResultTy = IntegerType::get(Context, Record[0]);
965      break;
966    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
967                                    //          [pointee type, address space]
968      if (Record.size() < 1)
969        return Error("Invalid record");
970      unsigned AddressSpace = 0;
971      if (Record.size() == 2)
972        AddressSpace = Record[1];
973      ResultTy = getTypeByID(Record[0]);
974      if (!ResultTy)
975        return Error("Invalid type");
976      ResultTy = PointerType::get(ResultTy, AddressSpace);
977      break;
978    }
979    case bitc::TYPE_CODE_FUNCTION_OLD: {
980      // FIXME: attrid is dead, remove it in LLVM 4.0
981      // FUNCTION: [vararg, attrid, retty, paramty x N]
982      if (Record.size() < 3)
983        return Error("Invalid record");
984      SmallVector<Type*, 8> ArgTys;
985      for (unsigned i = 3, e = Record.size(); i != e; ++i) {
986        if (Type *T = getTypeByID(Record[i]))
987          ArgTys.push_back(T);
988        else
989          break;
990      }
991
992      ResultTy = getTypeByID(Record[2]);
993      if (!ResultTy || ArgTys.size() < Record.size()-3)
994        return Error("Invalid type");
995
996      ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
997      break;
998    }
999    case bitc::TYPE_CODE_STRUCT_ANON: {  // STRUCT: [ispacked, eltty x N]
1000      if (Record.size() < 1)
1001        return Error("Invalid record");
1002      SmallVector<Type*, 8> EltTys;
1003      for (unsigned i = 1, e = Record.size(); i != e; ++i) {
1004        if (Type *T = getTypeByID(Record[i]))
1005          EltTys.push_back(T);
1006        else
1007          break;
1008      }
1009      if (EltTys.size() != Record.size()-1)
1010        return Error("Invalid type");
1011      ResultTy = StructType::get(Context, EltTys, Record[0]);
1012      break;
1013    }
1014    case bitc::TYPE_CODE_STRUCT_NAME:   // STRUCT_NAME: [strchr x N]
1015      if (ConvertToString(Record, 0, TypeName))
1016        return Error("Invalid record");
1017      continue;
1018
1019    case bitc::TYPE_CODE_STRUCT_NAMED: { // STRUCT: [ispacked, eltty x N]
1020      if (Record.size() < 1)
1021        return Error("Invalid record");
1022
1023      if (NumRecords >= TypeList.size())
1024        return Error("Invalid TYPE table");
1025
1026      // Check to see if this was forward referenced, if so fill in the temp.
1027      StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
1028      if (Res) {
1029        Res->setName(TypeName);
1030        TypeList[NumRecords] = nullptr;
1031      } else  // Otherwise, create a new struct.
1032        Res = createIdentifiedStructType(Context, TypeName);
1033      TypeName.clear();
1034
1035      SmallVector<Type*, 8> EltTys;
1036      for (unsigned i = 1, e = Record.size(); i != e; ++i) {
1037        if (Type *T = getTypeByID(Record[i]))
1038          EltTys.push_back(T);
1039        else
1040          break;
1041      }
1042      if (EltTys.size() != Record.size()-1)
1043        return Error("Invalid record");
1044      Res->setBody(EltTys, Record[0]);
1045      ResultTy = Res;
1046      break;
1047    }
1048    case bitc::TYPE_CODE_OPAQUE: {       // OPAQUE: []
1049      if (Record.size() != 1)
1050        return Error("Invalid record");
1051
1052      if (NumRecords >= TypeList.size())
1053        return Error("Invalid TYPE table");
1054
1055      // Check to see if this was forward referenced, if so fill in the temp.
1056      StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
1057      if (Res) {
1058        Res->setName(TypeName);
1059        TypeList[NumRecords] = nullptr;
1060      } else  // Otherwise, create a new struct with no body.
1061        Res = createIdentifiedStructType(Context, TypeName);
1062      TypeName.clear();
1063      ResultTy = Res;
1064      break;
1065    }
1066    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
1067      if (Record.size() < 2)
1068        return Error("Invalid record");
1069      if ((ResultTy = getTypeByID(Record[1])))
1070        ResultTy = ArrayType::get(ResultTy, Record[0]);
1071      else
1072        return Error("Invalid type");
1073      break;
1074    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
1075      if (Record.size() < 2)
1076        return Error("Invalid record");
1077      if ((ResultTy = getTypeByID(Record[1])))
1078        ResultTy = VectorType::get(ResultTy, Record[0]);
1079      else
1080        return Error("Invalid type");
1081      break;
1082    }
1083
1084    if (NumRecords >= TypeList.size())
1085      return Error("Invalid TYPE table");
1086    assert(ResultTy && "Didn't read a type?");
1087    assert(!TypeList[NumRecords] && "Already read type?");
1088    TypeList[NumRecords++] = ResultTy;
1089  }
1090}
1091
1092// FIXME: Remove in LLVM 3.1
1093std::error_code BitcodeReader::ParseOldTypeTable() {
1094  if (Stream.EnterSubBlock(TYPE_BLOCK_ID_OLD_3_0))
1095    return Error("Malformed block");
1096
1097  if (!TypeList.empty())
1098    return Error("Invalid TYPE table");
1099
1100
1101  // While horrible, we have no good ordering of types in the bc file.  Just
1102  // iteratively parse types out of the bc file in multiple passes until we get
1103  // them all.  Do this by saving a cursor for the start of the type block.
1104  BitstreamCursor StartOfTypeBlockCursor(Stream);
1105
1106  unsigned NumTypesRead = 0;
1107
1108  SmallVector<uint64_t, 64> Record;
1109RestartScan:
1110  unsigned NextTypeID = 0;
1111  bool ReadAnyTypes = false;
1112
1113  // Read all the records for this type table.
1114  while (1) {
1115    unsigned Code = Stream.ReadCode();
1116    if (Code == bitc::END_BLOCK) {
1117      if (NextTypeID != TypeList.size())
1118        return Error("Invalid TYPE table");
1119
1120      // If we haven't read all of the types yet, iterate again.
1121      if (NumTypesRead != TypeList.size()) {
1122        // If we didn't successfully read any types in this pass, then we must
1123        // have an unhandled forward reference.
1124        if (!ReadAnyTypes)
1125          return Error("Invalid TYPE table");
1126
1127        Stream = StartOfTypeBlockCursor;
1128        goto RestartScan;
1129      }
1130
1131      if (Stream.ReadBlockEnd())
1132        return Error("Invalid TYPE table");
1133      return std::error_code();
1134    }
1135
1136    if (Code == bitc::ENTER_SUBBLOCK) {
1137      // No known subblocks, always skip them.
1138      Stream.ReadSubBlockID();
1139      if (Stream.SkipBlock())
1140        return Error("Malformed block");
1141      continue;
1142    }
1143
1144    if (Code == bitc::DEFINE_ABBREV) {
1145      Stream.ReadAbbrevRecord();
1146      continue;
1147    }
1148
1149    // Read a record.
1150    Record.clear();
1151    Type *ResultTy = nullptr;
1152    switch (Stream.readRecord(Code, Record)) {
1153    default: return Error("Invalid TYPE table");
1154    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
1155      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
1156      // type list.  This allows us to reserve space.
1157      if (Record.size() < 1)
1158        return Error("Invalid TYPE table");
1159      TypeList.resize(Record[0]);
1160      continue;
1161    case bitc::TYPE_CODE_VOID:      // VOID
1162      ResultTy = Type::getVoidTy(Context);
1163      break;
1164    case bitc::TYPE_CODE_FLOAT:     // FLOAT
1165      ResultTy = Type::getFloatTy(Context);
1166      break;
1167    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
1168      ResultTy = Type::getDoubleTy(Context);
1169      break;
1170    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
1171      ResultTy = Type::getX86_FP80Ty(Context);
1172      break;
1173    case bitc::TYPE_CODE_FP128:     // FP128
1174      ResultTy = Type::getFP128Ty(Context);
1175      break;
1176    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
1177      ResultTy = Type::getPPC_FP128Ty(Context);
1178      break;
1179    case bitc::TYPE_CODE_LABEL:     // LABEL
1180      ResultTy = Type::getLabelTy(Context);
1181      break;
1182    case bitc::TYPE_CODE_METADATA:  // METADATA
1183      ResultTy = Type::getMetadataTy(Context);
1184      break;
1185    case bitc::TYPE_CODE_X86_MMX:   // X86_MMX
1186      ResultTy = Type::getX86_MMXTy(Context);
1187      break;
1188    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
1189      if (Record.size() < 1)
1190        return Error("Invalid TYPE table");
1191      ResultTy = IntegerType::get(Context, Record[0]);
1192      break;
1193    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
1194      if (NextTypeID < TypeList.size() && TypeList[NextTypeID] == 0)
1195        ResultTy = StructType::create(Context, "");
1196      break;
1197    case TYPE_CODE_STRUCT_OLD_3_0: {// STRUCT_OLD
1198      if (NextTypeID >= TypeList.size()) break;
1199      // If we already read it, don't reprocess.
1200      if (TypeList[NextTypeID] &&
1201          !cast<StructType>(TypeList[NextTypeID])->isOpaque())
1202        break;
1203
1204      // Set a type.
1205      if (TypeList[NextTypeID] == 0)
1206        TypeList[NextTypeID] = StructType::create(Context, "");
1207
1208      std::vector<Type*> EltTys;
1209      for (unsigned i = 1, e = Record.size(); i != e; ++i) {
1210        if (Type *Elt = getTypeByIDOrNull(Record[i]))
1211          EltTys.push_back(Elt);
1212        else
1213          break;
1214      }
1215
1216      if (EltTys.size() != Record.size()-1)
1217        break;      // Not all elements are ready.
1218
1219      cast<StructType>(TypeList[NextTypeID])->setBody(EltTys, Record[0]);
1220      ResultTy = TypeList[NextTypeID];
1221      TypeList[NextTypeID] = 0;
1222      break;
1223    }
1224    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
1225      //          [pointee type, address space]
1226      if (Record.size() < 1)
1227        return Error("Invalid TYPE table");
1228      unsigned AddressSpace = 0;
1229      if (Record.size() == 2)
1230        AddressSpace = Record[1];
1231      if ((ResultTy = getTypeByIDOrNull(Record[0])))
1232        ResultTy = PointerType::get(ResultTy, AddressSpace);
1233      break;
1234    }
1235    case bitc::TYPE_CODE_FUNCTION_OLD: {
1236      // FIXME: attrid is dead, remove it in LLVM 3.0
1237      // FUNCTION: [vararg, attrid, retty, paramty x N]
1238      if (Record.size() < 3)
1239        return Error("Invalid TYPE table");
1240      std::vector<Type*> ArgTys;
1241      for (unsigned i = 3, e = Record.size(); i != e; ++i) {
1242        if (Type *Elt = getTypeByIDOrNull(Record[i]))
1243          ArgTys.push_back(Elt);
1244        else
1245          break;
1246      }
1247      if (ArgTys.size()+3 != Record.size())
1248        break;  // Something was null.
1249      if ((ResultTy = getTypeByIDOrNull(Record[2])))
1250        ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
1251      break;
1252    }
1253    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
1254      if (Record.size() < 2)
1255        return Error("Invalid TYPE table");
1256      if ((ResultTy = getTypeByIDOrNull(Record[1])))
1257        ResultTy = ArrayType::get(ResultTy, Record[0]);
1258      break;
1259    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
1260      if (Record.size() < 2)
1261        return Error("Invalid TYPE table");
1262      if ((ResultTy = getTypeByIDOrNull(Record[1])))
1263        ResultTy = VectorType::get(ResultTy, Record[0]);
1264      break;
1265    }
1266
1267    if (NextTypeID >= TypeList.size())
1268      return Error("Invalid TYPE table");
1269
1270    if (ResultTy && TypeList[NextTypeID] == 0) {
1271      ++NumTypesRead;
1272      ReadAnyTypes = true;
1273
1274      TypeList[NextTypeID] = ResultTy;
1275    }
1276
1277    ++NextTypeID;
1278  }
1279}
1280
1281
1282std::error_code BitcodeReader::ParseOldTypeSymbolTable() {
1283  if (Stream.EnterSubBlock(TYPE_SYMTAB_BLOCK_ID_OLD_3_0))
1284    return Error("Malformed block");
1285
1286  SmallVector<uint64_t, 64> Record;
1287
1288  // Read all the records for this type table.
1289  std::string TypeName;
1290  while (1) {
1291    unsigned Code = Stream.ReadCode();
1292    if (Code == bitc::END_BLOCK) {
1293      if (Stream.ReadBlockEnd())
1294        return Error("Malformed block");
1295      return std::error_code();
1296    }
1297
1298    if (Code == bitc::ENTER_SUBBLOCK) {
1299      // No known subblocks, always skip them.
1300      Stream.ReadSubBlockID();
1301      if (Stream.SkipBlock())
1302        return Error("Malformed block");
1303      continue;
1304    }
1305
1306    if (Code == bitc::DEFINE_ABBREV) {
1307      Stream.ReadAbbrevRecord();
1308      continue;
1309    }
1310
1311    // Read a record.
1312    Record.clear();
1313    switch (Stream.readRecord(Code, Record)) {
1314    default:  // Default behavior: unknown type.
1315      break;
1316    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namechar x N]
1317      if (ConvertToString(Record, 1, TypeName))
1318        return Error("Invalid record");
1319      unsigned TypeID = Record[0];
1320      if (TypeID >= TypeList.size())
1321        return Error("Invalid record");
1322
1323      // Only apply the type name to a struct type with no name.
1324      if (StructType *STy = dyn_cast<StructType>(TypeList[TypeID]))
1325        if (!STy->isLiteral() && !STy->hasName())
1326          STy->setName(TypeName);
1327      TypeName.clear();
1328      break;
1329    }
1330  }
1331}
1332
1333std::error_code BitcodeReader::ParseValueSymbolTable() {
1334  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
1335    return Error("Invalid record");
1336
1337  SmallVector<uint64_t, 64> Record;
1338
1339  // Read all the records for this value table.
1340  SmallString<128> ValueName;
1341  while (1) {
1342    unsigned Code = Stream.ReadCode();
1343    if (Code == bitc::END_BLOCK) {
1344      if (Stream.ReadBlockEnd())
1345        return Error("Malformed block");
1346      return std::error_code();
1347    }
1348    if (Code == bitc::ENTER_SUBBLOCK) {
1349      // No known subblocks, always skip them.
1350      Stream.ReadSubBlockID();
1351      if (Stream.SkipBlock())
1352        return Error("Malformed block");
1353      continue;
1354    }
1355
1356    if (Code == bitc::DEFINE_ABBREV) {
1357      Stream.ReadAbbrevRecord();
1358      continue;
1359    }
1360
1361    // Read a record.
1362    Record.clear();
1363    switch (Stream.readRecord(Code, Record)) {
1364    default:  // Default behavior: unknown type.
1365      break;
1366    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
1367      if (ConvertToString(Record, 1, ValueName))
1368        return Error("Invalid record");
1369      unsigned ValueID = Record[0];
1370      if (ValueID >= ValueList.size())
1371        return Error("Invalid record");
1372      Value *V = ValueList[ValueID];
1373
1374      V->setName(StringRef(ValueName.data(), ValueName.size()));
1375      ValueName.clear();
1376      break;
1377    }
1378    case bitc::VST_CODE_BBENTRY: {
1379      if (ConvertToString(Record, 1, ValueName))
1380        return Error("Invalid record");
1381      BasicBlock *BB = getBasicBlock(Record[0]);
1382      if (!BB)
1383        return Error("Invalid record");
1384
1385      BB->setName(StringRef(ValueName.data(), ValueName.size()));
1386      ValueName.clear();
1387      break;
1388    }
1389    }
1390  }
1391}
1392
1393std::error_code BitcodeReader::ParseMetadata() {
1394  unsigned NextMDValueNo = MDValueList.size();
1395
1396  if (Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
1397    return Error("Invalid record");
1398
1399  SmallVector<uint64_t, 64> Record;
1400
1401  // Read all the records.
1402  while (1) {
1403    unsigned Code = Stream.ReadCode();
1404    if (Code == bitc::END_BLOCK) {
1405      if (Stream.ReadBlockEnd())
1406        return Error("Malformed block");
1407      return std::error_code();
1408    }
1409
1410    if (Code == bitc::ENTER_SUBBLOCK) {
1411      // No known subblocks, always skip them.
1412      Stream.ReadSubBlockID();
1413      if (Stream.SkipBlock())
1414        return Error("Malformed block");
1415      continue;
1416    }
1417
1418    if (Code == bitc::DEFINE_ABBREV) {
1419      Stream.ReadAbbrevRecord();
1420      continue;
1421    }
1422
1423    bool IsFunctionLocal = false;
1424    // Read a record.
1425    Record.clear();
1426    Code = Stream.readRecord(Code, Record);
1427    switch (Code) {
1428    default:  // Default behavior: ignore.
1429      break;
1430    case bitc::METADATA_NAME: {
1431      // Read named of the named metadata.
1432      unsigned NameLength = Record.size();
1433      SmallString<8> Name;
1434      Name.resize(NameLength);
1435      for (unsigned i = 0; i != NameLength; ++i)
1436        Name[i] = Record[i];
1437      Record.clear();
1438      Code = Stream.ReadCode();
1439
1440      // METADATA_NAME is always followed by METADATA_NAMED_NODE.
1441      unsigned NextBitCode = Stream.readRecord(Code, Record);
1442      if (NextBitCode == METADATA_NAMED_NODE_2_7) {
1443        LLVM2_7MetadataDetected = true;
1444      } else if (NextBitCode != bitc::METADATA_NAMED_NODE) {
1445        assert(!"Invalid Named Metadata record.");  (void)NextBitCode;
1446      }
1447
1448      // Read named metadata elements.
1449      unsigned Size = Record.size();
1450      NamedMDNode *NMD = TheModule->getOrInsertNamedMetadata(Name);
1451      for (unsigned i = 0; i != Size; ++i) {
1452        MDNode *MD = dyn_cast_or_null<MDNode>(MDValueList.getValueFwdRef(Record[i]));
1453        if (!MD)
1454          return Error("Invalid record");
1455        NMD->addOperand(MD);
1456      }
1457
1458      if (LLVM2_7MetadataDetected) {
1459        MDValueList.AssignValue(0, NextMDValueNo++);
1460      }
1461      break;
1462    }
1463    case METADATA_FN_NODE_2_7:
1464    case bitc::METADATA_OLD_FN_NODE:
1465      IsFunctionLocal = true;
1466      // fall-through
1467    case METADATA_NODE_2_7:
1468    case bitc::METADATA_OLD_NODE: {
1469      if (Code == METADATA_FN_NODE_2_7 ||
1470          Code == METADATA_NODE_2_7) {
1471        LLVM2_7MetadataDetected = true;
1472      }
1473
1474      if (Record.size() % 2 == 1)
1475        return Error("Invalid record");
1476
1477      unsigned Size = Record.size();
1478      SmallVector<Metadata *, 8> Elts;
1479      for (unsigned i = 0; i != Size; i += 2) {
1480        Type *Ty = getTypeByID(Record[i]);
1481        if (!Ty)
1482          return Error("Invalid record");
1483        if (Ty->isMetadataTy())
1484          Elts.push_back(MDValueList.getValueFwdRef(Record[i+1]));
1485        else if (!Ty->isVoidTy()) {
1486          auto *MD =
1487              ValueAsMetadata::get(ValueList.getValueFwdRef(Record[i + 1], Ty));
1488          assert(isa<ConstantAsMetadata>(MD) &&
1489                 "Expected non-function-local metadata");
1490          Elts.push_back(MD);
1491        } else
1492          Elts.push_back(nullptr);
1493      }
1494      MDValueList.AssignValue(MDNode::get(Context, Elts), NextMDValueNo++);
1495      break;
1496    }
1497    case bitc::METADATA_STRING: {
1498      std::string String(Record.begin(), Record.end());
1499      llvm::UpgradeMDStringConstant(String);
1500      Metadata *MD = MDString::get(Context, String);
1501      MDValueList.AssignValue(MD, NextMDValueNo++);
1502      break;
1503    }
1504    case bitc::METADATA_KIND: {
1505      if (Record.size() < 2)
1506        return Error("Invalid record");
1507
1508      unsigned Kind = Record[0];
1509      SmallString<8> Name(Record.begin()+1, Record.end());
1510
1511      unsigned NewKind = TheModule->getMDKindID(Name.str());
1512      if (!MDKindMap.insert(std::make_pair(Kind, NewKind)).second)
1513        return Error("Conflicting METADATA_KIND records");
1514      break;
1515    }
1516    }
1517  }
1518}
1519
1520/// decodeSignRotatedValue - Decode a signed value stored with the sign bit in
1521/// the LSB for dense VBR encoding.
1522uint64_t BitcodeReader::decodeSignRotatedValue(uint64_t V) {
1523  if ((V & 1) == 0)
1524    return V >> 1;
1525  if (V != 1)
1526    return -(V >> 1);
1527  // There is no such thing as -0 with integers.  "-0" really means MININT.
1528  return 1ULL << 63;
1529}
1530
1531// FIXME: Delete this in LLVM 4.0 and just assert that the aliasee is a
1532// GlobalObject.
1533static GlobalObject &
1534getGlobalObjectInExpr(const DenseMap<GlobalAlias *, Constant *> &Map,
1535                      Constant &C) {
1536  auto *GO = dyn_cast<GlobalObject>(&C);
1537  if (GO)
1538    return *GO;
1539
1540  auto *GA = dyn_cast<GlobalAlias>(&C);
1541  if (GA)
1542    return getGlobalObjectInExpr(Map, *Map.find(GA)->second);
1543
1544  auto &CE = cast<ConstantExpr>(C);
1545  assert(CE.getOpcode() == Instruction::BitCast ||
1546         CE.getOpcode() == Instruction::GetElementPtr ||
1547         CE.getOpcode() == Instruction::AddrSpaceCast);
1548  if (CE.getOpcode() == Instruction::GetElementPtr)
1549    assert(cast<GEPOperator>(CE).hasAllZeroIndices());
1550  return getGlobalObjectInExpr(Map, *CE.getOperand(0));
1551}
1552
1553/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
1554/// values and aliases that we can.
1555std::error_code BitcodeReader::ResolveGlobalAndAliasInits() {
1556  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
1557  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
1558
1559  GlobalInitWorklist.swap(GlobalInits);
1560  AliasInitWorklist.swap(AliasInits);
1561
1562  while (!GlobalInitWorklist.empty()) {
1563    unsigned ValID = GlobalInitWorklist.back().second;
1564    if (ValID >= ValueList.size()) {
1565      // Not ready to resolve this yet, it requires something later in the file.
1566      GlobalInits.push_back(GlobalInitWorklist.back());
1567    } else {
1568      if (Constant *C = dyn_cast_or_null<Constant>(ValueList[ValID]))
1569        GlobalInitWorklist.back().first->setInitializer(C);
1570      else
1571        return Error("Expected a constant");
1572    }
1573    GlobalInitWorklist.pop_back();
1574  }
1575
1576  // FIXME: Delete this in LLVM 4.0
1577  // Older versions of llvm could write an alias pointing to another. We cannot
1578  // construct those aliases, so we first collect an alias to aliasee expression
1579  // and then compute the actual aliasee.
1580  DenseMap<GlobalAlias *, Constant *> AliasInit;
1581
1582  while (!AliasInitWorklist.empty()) {
1583    unsigned ValID = AliasInitWorklist.back().second;
1584    if (ValID >= ValueList.size()) {
1585      AliasInits.push_back(AliasInitWorklist.back());
1586    } else {
1587      if (Constant *C = dyn_cast_or_null<Constant>(ValueList[ValID]))
1588        AliasInit.insert(std::make_pair(AliasInitWorklist.back().first, C));
1589      else
1590        return Error("Expected a constant");
1591    }
1592    AliasInitWorklist.pop_back();
1593  }
1594
1595  for (auto &Pair : AliasInit) {
1596    auto &GO = getGlobalObjectInExpr(AliasInit, *Pair.second);
1597    Pair.first->setAliasee(&GO);
1598  }
1599
1600  return std::error_code();
1601}
1602
1603static APInt ReadWideAPInt(ArrayRef<uint64_t> Vals, unsigned TypeBits) {
1604  SmallVector<uint64_t, 8> Words(Vals.size());
1605  std::transform(Vals.begin(), Vals.end(), Words.begin(),
1606                 BitcodeReader::decodeSignRotatedValue);
1607
1608  return APInt(TypeBits, Words);
1609}
1610
1611std::error_code BitcodeReader::ParseConstants() {
1612  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
1613    return Error("Invalid record");
1614
1615  SmallVector<uint64_t, 64> Record;
1616
1617  // Read all the records for this value table.
1618  Type *CurTy = Type::getInt32Ty(Context);
1619  unsigned NextCstNo = ValueList.size();
1620  while (1) {
1621    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
1622
1623    switch (Entry.Kind) {
1624    case BitstreamEntry::SubBlock: // Handled for us already.
1625    case BitstreamEntry::Error:
1626      return Error("Malformed block");
1627    case BitstreamEntry::EndBlock:
1628      if (NextCstNo != ValueList.size())
1629        return Error("Invalid constant reference");
1630
1631      // Once all the constants have been read, go through and resolve forward
1632      // references.
1633      ValueList.ResolveConstantForwardRefs();
1634      return std::error_code();
1635    case BitstreamEntry::Record:
1636      // The interesting case.
1637      break;
1638    }
1639
1640    // Read a record.
1641    Record.clear();
1642    Value *V = nullptr;
1643    unsigned BitCode = Stream.readRecord(Entry.ID, Record);
1644    switch (BitCode) {
1645    default:  // Default behavior: unknown constant
1646    case bitc::CST_CODE_UNDEF:     // UNDEF
1647      V = UndefValue::get(CurTy);
1648      break;
1649    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
1650      if (Record.empty())
1651        return Error("Invalid record");
1652      if (Record[0] >= TypeList.size())
1653        return Error("Invalid record");
1654      CurTy = TypeList[Record[0]];
1655      continue;  // Skip the ValueList manipulation.
1656    case bitc::CST_CODE_NULL:      // NULL
1657      V = Constant::getNullValue(CurTy);
1658      break;
1659    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
1660      if (!CurTy->isIntegerTy() || Record.empty())
1661        return Error("Invalid record");
1662      V = ConstantInt::get(CurTy, decodeSignRotatedValue(Record[0]));
1663      break;
1664    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
1665      if (!CurTy->isIntegerTy() || Record.empty())
1666        return Error("Invalid record");
1667
1668      APInt VInt = ReadWideAPInt(Record,
1669                                 cast<IntegerType>(CurTy)->getBitWidth());
1670      V = ConstantInt::get(Context, VInt);
1671
1672      break;
1673    }
1674    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
1675      if (Record.empty())
1676        return Error("Invalid record");
1677      if (CurTy->isHalfTy())
1678        V = ConstantFP::get(Context, APFloat(APFloat::IEEEhalf,
1679                                             APInt(16, (uint16_t)Record[0])));
1680      else if (CurTy->isFloatTy())
1681        V = ConstantFP::get(Context, APFloat(APFloat::IEEEsingle,
1682                                             APInt(32, (uint32_t)Record[0])));
1683      else if (CurTy->isDoubleTy())
1684        V = ConstantFP::get(Context, APFloat(APFloat::IEEEdouble,
1685                                             APInt(64, Record[0])));
1686      else if (CurTy->isX86_FP80Ty()) {
1687        // Bits are not stored the same way as a normal i80 APInt, compensate.
1688        uint64_t Rearrange[2];
1689        Rearrange[0] = (Record[1] & 0xffffLL) | (Record[0] << 16);
1690        Rearrange[1] = Record[0] >> 48;
1691        V = ConstantFP::get(Context, APFloat(APFloat::x87DoubleExtended,
1692                                             APInt(80, Rearrange)));
1693      } else if (CurTy->isFP128Ty())
1694        V = ConstantFP::get(Context, APFloat(APFloat::IEEEquad,
1695                                             APInt(128, Record)));
1696      else if (CurTy->isPPC_FP128Ty())
1697        V = ConstantFP::get(Context, APFloat(APFloat::PPCDoubleDouble,
1698                                             APInt(128, Record)));
1699      else
1700        V = UndefValue::get(CurTy);
1701      break;
1702    }
1703
1704    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
1705      if (Record.empty())
1706        return Error("Invalid record");
1707
1708      unsigned Size = Record.size();
1709      SmallVector<Constant*, 16> Elts;
1710
1711      if (StructType *STy = dyn_cast<StructType>(CurTy)) {
1712        for (unsigned i = 0; i != Size; ++i)
1713          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
1714                                                     STy->getElementType(i)));
1715        V = ConstantStruct::get(STy, Elts);
1716      } else if (ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
1717        Type *EltTy = ATy->getElementType();
1718        for (unsigned i = 0; i != Size; ++i)
1719          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1720        V = ConstantArray::get(ATy, Elts);
1721      } else if (VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
1722        Type *EltTy = VTy->getElementType();
1723        for (unsigned i = 0; i != Size; ++i)
1724          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1725        V = ConstantVector::get(Elts);
1726      } else {
1727        V = UndefValue::get(CurTy);
1728      }
1729      break;
1730    }
1731    case bitc::CST_CODE_STRING: { // STRING: [values]
1732      if (Record.empty())
1733        return Error("Invalid record");
1734
1735      ArrayType *ATy = cast<ArrayType>(CurTy);
1736      Type *EltTy = ATy->getElementType();
1737
1738      unsigned Size = Record.size();
1739      std::vector<Constant*> Elts;
1740      for (unsigned i = 0; i != Size; ++i)
1741        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
1742      V = ConstantArray::get(ATy, Elts);
1743      break;
1744    }
1745    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
1746      if (Record.empty())
1747        return Error("Invalid record");
1748
1749      ArrayType *ATy = cast<ArrayType>(CurTy);
1750      Type *EltTy = ATy->getElementType();
1751
1752      unsigned Size = Record.size();
1753      std::vector<Constant*> Elts;
1754      for (unsigned i = 0; i != Size; ++i)
1755        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
1756      Elts.push_back(Constant::getNullValue(EltTy));
1757      V = ConstantArray::get(ATy, Elts);
1758      break;
1759    }
1760    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
1761      if (Record.size() < 3)
1762        return Error("Invalid record");
1763      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
1764      if (Opc < 0) {
1765        V = UndefValue::get(CurTy);  // Unknown binop.
1766      } else {
1767        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
1768        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
1769        unsigned Flags = 0;
1770        if (Record.size() >= 4) {
1771          if (Opc == Instruction::Add ||
1772              Opc == Instruction::Sub ||
1773              Opc == Instruction::Mul ||
1774              Opc == Instruction::Shl) {
1775            if (Record[3] & (1 << bitc::OBO_NO_SIGNED_WRAP))
1776              Flags |= OverflowingBinaryOperator::NoSignedWrap;
1777            if (Record[3] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
1778              Flags |= OverflowingBinaryOperator::NoUnsignedWrap;
1779          } else if (Opc == Instruction::SDiv ||
1780                     Opc == Instruction::UDiv ||
1781                     Opc == Instruction::LShr ||
1782                     Opc == Instruction::AShr) {
1783            if (Record[3] & (1 << bitc::PEO_EXACT))
1784              Flags |= SDivOperator::IsExact;
1785          }
1786        }
1787        V = ConstantExpr::get(Opc, LHS, RHS, Flags);
1788      }
1789      break;
1790    }
1791    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
1792      if (Record.size() < 3)
1793        return Error("Invalid record");
1794      int Opc = GetDecodedCastOpcode(Record[0]);
1795      if (Opc < 0) {
1796        V = UndefValue::get(CurTy);  // Unknown cast.
1797      } else {
1798        Type *OpTy = getTypeByID(Record[1]);
1799        if (!OpTy)
1800          return Error("Invalid record");
1801        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
1802        V = ConstantExpr::getCast(Opc, Op, CurTy);
1803      }
1804      break;
1805    }
1806    case bitc::CST_CODE_CE_INBOUNDS_GEP:
1807    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
1808      if (Record.size() & 1)
1809        return Error("Invalid record");
1810      SmallVector<Constant*, 16> Elts;
1811      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
1812        Type *ElTy = getTypeByID(Record[i]);
1813        if (!ElTy)
1814          return Error("Invalid record");
1815        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
1816      }
1817      ArrayRef<Constant *> Indices(Elts.begin() + 1, Elts.end());
1818      V = ConstantExpr::getGetElementPtr(Elts[0], Indices,
1819                                         BitCode ==
1820                                           bitc::CST_CODE_CE_INBOUNDS_GEP);
1821      break;
1822    }
1823    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
1824      if (Record.size() < 3)
1825        return Error("Invalid record");
1826      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
1827                                                              Type::getInt1Ty(Context)),
1828                                  ValueList.getConstantFwdRef(Record[1],CurTy),
1829                                  ValueList.getConstantFwdRef(Record[2],CurTy));
1830      break;
1831    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
1832      if (Record.size() < 3)
1833        return Error("Invalid record");
1834      VectorType *OpTy =
1835        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1836      if (!OpTy)
1837        return Error("Invalid record");
1838      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1839      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
1840      V = ConstantExpr::getExtractElement(Op0, Op1);
1841      break;
1842    }
1843    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
1844      VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1845      if (Record.size() < 3 || !OpTy)
1846        return Error("Invalid record");
1847      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1848      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
1849                                                  OpTy->getElementType());
1850      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
1851      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
1852      break;
1853    }
1854    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
1855      VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1856      if (Record.size() < 3 || !OpTy)
1857        return Error("Invalid record");
1858      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1859      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
1860      Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
1861                                                 OpTy->getNumElements());
1862      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
1863      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1864      break;
1865    }
1866    case bitc::CST_CODE_CE_SHUFVEC_EX: { // [opty, opval, opval, opval]
1867      VectorType *RTy = dyn_cast<VectorType>(CurTy);
1868      VectorType *OpTy =
1869        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1870      if (Record.size() < 4 || !RTy || !OpTy)
1871        return Error("Invalid record");
1872      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1873      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1874      Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
1875                                                 RTy->getNumElements());
1876      Constant *Op2 = ValueList.getConstantFwdRef(Record[3], ShufTy);
1877      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1878      break;
1879    }
1880    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
1881      if (Record.size() < 4)
1882        return Error("Invalid record");
1883      Type *OpTy = getTypeByID(Record[0]);
1884      if (!OpTy)
1885        return Error("Invalid record");
1886      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1887      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1888
1889      if (OpTy->isFPOrFPVectorTy())
1890        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
1891      else
1892        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
1893      break;
1894    }
1895    case bitc::CST_CODE_INLINEASM:
1896    case bitc::CST_CODE_INLINEASM_OLD: {
1897      if (Record.size() < 2)
1898        return Error("Invalid record");
1899      std::string AsmStr, ConstrStr;
1900      bool HasSideEffects = Record[0] & 1;
1901      bool IsAlignStack = Record[0] >> 1;
1902      unsigned AsmStrSize = Record[1];
1903      if (2+AsmStrSize >= Record.size())
1904        return Error("Invalid record");
1905      unsigned ConstStrSize = Record[2+AsmStrSize];
1906      if (3+AsmStrSize+ConstStrSize > Record.size())
1907        return Error("Invalid record");
1908
1909      for (unsigned i = 0; i != AsmStrSize; ++i)
1910        AsmStr += (char)Record[2+i];
1911      for (unsigned i = 0; i != ConstStrSize; ++i)
1912        ConstrStr += (char)Record[3+AsmStrSize+i];
1913      PointerType *PTy = cast<PointerType>(CurTy);
1914      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
1915                         AsmStr, ConstrStr, HasSideEffects, IsAlignStack);
1916      break;
1917    }
1918    case bitc::CST_CODE_BLOCKADDRESS:{
1919      if (Record.size() < 3)
1920        return Error("Invalid record");
1921      Type *FnTy = getTypeByID(Record[0]);
1922      if (!FnTy)
1923        return Error("Invalid record");
1924      Function *Fn =
1925        dyn_cast_or_null<Function>(ValueList.getConstantFwdRef(Record[1],FnTy));
1926      if (!Fn)
1927        return Error("Invalid record");
1928
1929      GlobalVariable *FwdRef = new GlobalVariable(*Fn->getParent(),
1930                                                  Type::getInt8Ty(Context),
1931                                            false, GlobalValue::InternalLinkage,
1932                                                  0, "");
1933      BlockAddrFwdRefs[Fn].push_back(std::make_pair(Record[2], FwdRef));
1934      V = FwdRef;
1935      break;
1936    }
1937    }
1938
1939    ValueList.AssignValue(V, NextCstNo);
1940    ++NextCstNo;
1941  }
1942
1943  if (NextCstNo != ValueList.size())
1944    return Error("Invalid constant reference");
1945
1946  if (Stream.ReadBlockEnd())
1947    return Error("Expected a constant");
1948
1949  // Once all the constants have been read, go through and resolve forward
1950  // references.
1951  ValueList.ResolveConstantForwardRefs();
1952  return std::error_code();
1953}
1954
1955std::error_code BitcodeReader::materializeMetadata() {
1956  return std::error_code();
1957}
1958
1959/// RememberAndSkipFunctionBody - When we see the block for a function body,
1960/// remember where it is and then skip it.  This lets us lazily deserialize the
1961/// functions.
1962std::error_code BitcodeReader::RememberAndSkipFunctionBody() {
1963  // Get the function we are talking about.
1964  if (FunctionsWithBodies.empty())
1965    return Error("Insufficient function protos");
1966
1967  Function *Fn = FunctionsWithBodies.back();
1968  FunctionsWithBodies.pop_back();
1969
1970  // Save the current stream state.
1971  uint64_t CurBit = Stream.GetCurrentBitNo();
1972  DeferredFunctionInfo[Fn] = CurBit;
1973
1974  // Skip over the function block for now.
1975  if (Stream.SkipBlock())
1976    return Error("Invalid record");
1977  return std::error_code();
1978}
1979
1980std::error_code BitcodeReader::GlobalCleanup() {
1981  // Patch the initializers for globals and aliases up.
1982  ResolveGlobalAndAliasInits();
1983  if (!GlobalInits.empty() || !AliasInits.empty())
1984    return Error("Malformed global initializer set");
1985
1986  // Look for intrinsic functions which need to be upgraded at some point
1987  for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
1988       FI != FE; ++FI) {
1989    Function *NewFn;
1990    if (UpgradeIntrinsicFunction(FI, NewFn))
1991      UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
1992  }
1993
1994  // Look for global variables which need to be renamed.
1995  for (Module::global_iterator
1996         GI = TheModule->global_begin(), GE = TheModule->global_end();
1997       GI != GE;) {
1998    GlobalVariable *GV = GI++;
1999    UpgradeGlobalVariable(GV);
2000  }
2001
2002  // Force deallocation of memory for these vectors to favor the client that
2003  // want lazy deserialization.
2004  std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
2005  std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
2006  return std::error_code();
2007}
2008
2009std::error_code BitcodeReader::ParseModule(bool Resume) {
2010  if (Resume)
2011    Stream.JumpToBit(NextUnreadBit);
2012  else if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
2013    return Error("Invalid record");
2014
2015  SmallVector<uint64_t, 64> Record;
2016  std::vector<std::string> SectionTable;
2017  std::vector<std::string> GCTable;
2018
2019  // Read all the records for this module.
2020  while (!Stream.AtEndOfStream()) {
2021    unsigned Code = Stream.ReadCode();
2022    if (Code == bitc::END_BLOCK) {
2023      if (Stream.ReadBlockEnd())
2024        return Error("Malformed block");
2025
2026      // Patch the initializers for globals and aliases up.
2027      ResolveGlobalAndAliasInits();
2028      if (!GlobalInits.empty() || !AliasInits.empty())
2029        return Error("Malformed global initializer set");
2030      if (!FunctionsWithBodies.empty())
2031        return Error("Insufficient function protos");
2032
2033      // Look for intrinsic functions which need to be upgraded at some point
2034      for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
2035           FI != FE; ++FI) {
2036        Function* NewFn;
2037        if (UpgradeIntrinsicFunction(FI, NewFn))
2038          UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
2039      }
2040
2041      // Look for global variables which need to be renamed.
2042      for (Module::global_iterator
2043             GI = TheModule->global_begin(), GE = TheModule->global_end();
2044           GI != GE; ++GI)
2045        UpgradeGlobalVariable(GI);
2046
2047      // Force deallocation of memory for these vectors to favor the client that
2048      // want lazy deserialization.
2049      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
2050      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
2051      std::vector<Function*>().swap(FunctionsWithBodies);
2052      return std::error_code();
2053    }
2054
2055    if (Code == bitc::ENTER_SUBBLOCK) {
2056      switch (Stream.ReadSubBlockID()) {
2057      default:  // Skip unknown content.
2058        if (Stream.SkipBlock())
2059          return Error("Invalid record");
2060        break;
2061      case bitc::BLOCKINFO_BLOCK_ID:
2062        if (Stream.ReadBlockInfoBlock())
2063          return Error("Malformed block");
2064        break;
2065      case bitc::PARAMATTR_BLOCK_ID:
2066        if (std::error_code EC = ParseAttributeBlock())
2067          return EC;
2068        break;
2069      case bitc::TYPE_BLOCK_ID_NEW:
2070        if (std::error_code EC = ParseTypeTable())
2071          return EC;
2072        break;
2073      case TYPE_BLOCK_ID_OLD_3_0:
2074        if (std::error_code EC = ParseOldTypeTable())
2075          return EC;
2076        break;
2077      case TYPE_SYMTAB_BLOCK_ID_OLD_3_0:
2078        if (std::error_code EC = ParseOldTypeSymbolTable())
2079          return EC;
2080        break;
2081      case bitc::VALUE_SYMTAB_BLOCK_ID:
2082        if (std::error_code EC = ParseValueSymbolTable())
2083          return EC;
2084        SeenValueSymbolTable = true;
2085        break;
2086      case bitc::CONSTANTS_BLOCK_ID:
2087        if (std::error_code EC = ParseConstants())
2088          return EC;
2089        if (std::error_code EC = ResolveGlobalAndAliasInits())
2090          return EC;
2091        break;
2092      case bitc::METADATA_BLOCK_ID:
2093        if (std::error_code EC = ParseMetadata())
2094          return EC;
2095        break;
2096      case bitc::FUNCTION_BLOCK_ID:
2097        // If this is the first function body we've seen, reverse the
2098        // FunctionsWithBodies list.
2099        if (!SeenFirstFunctionBody) {
2100          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
2101          if (std::error_code EC = GlobalCleanup())
2102            return EC;
2103          SeenFirstFunctionBody = true;
2104        }
2105
2106        if (std::error_code EC = RememberAndSkipFunctionBody())
2107          return EC;
2108        // For streaming bitcode, suspend parsing when we reach the function
2109        // bodies. Subsequent materialization calls will resume it when
2110        // necessary. For streaming, the function bodies must be at the end of
2111        // the bitcode. If the bitcode file is old, the symbol table will be
2112        // at the end instead and will not have been seen yet. In this case,
2113        // just finish the parse now.
2114        if (LazyStreamer && SeenValueSymbolTable) {
2115          NextUnreadBit = Stream.GetCurrentBitNo();
2116          return std::error_code();
2117        }
2118        break;
2119        break;
2120      }
2121      continue;
2122    }
2123
2124    if (Code == bitc::DEFINE_ABBREV) {
2125      Stream.ReadAbbrevRecord();
2126      continue;
2127    }
2128
2129    // Read a record.
2130    switch (Stream.readRecord(Code, Record)) {
2131    default: break;  // Default behavior, ignore unknown content.
2132    case bitc::MODULE_CODE_VERSION: {  // VERSION: [version#]
2133      if (Record.size() < 1)
2134        return Error("Invalid record");
2135      // Only version #0 is supported so far.
2136      if (Record[0] != 0)
2137        return Error("Invalid value");
2138      break;
2139    }
2140    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
2141      std::string S;
2142      if (ConvertToString(Record, 0, S))
2143        return Error("Invalid record");
2144      TheModule->setTargetTriple(S);
2145      break;
2146    }
2147    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
2148      std::string S;
2149      if (ConvertToString(Record, 0, S))
2150        return Error("Invalid record");
2151      TheModule->setDataLayout(S);
2152      break;
2153    }
2154    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
2155      std::string S;
2156      if (ConvertToString(Record, 0, S))
2157        return Error("Invalid record");
2158      TheModule->setModuleInlineAsm(S);
2159      break;
2160    }
2161    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
2162      std::string S;
2163      if (ConvertToString(Record, 0, S))
2164        return Error("Invalid record");
2165      // ANDROID: Ignore value, since we never used it anyways.
2166      // TheModule->addLibrary(S);
2167      break;
2168    }
2169    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
2170      std::string S;
2171      if (ConvertToString(Record, 0, S))
2172        return Error("Invalid record");
2173      SectionTable.push_back(S);
2174      break;
2175    }
2176    case bitc::MODULE_CODE_GCNAME: {  // SECTIONNAME: [strchr x N]
2177      std::string S;
2178      if (ConvertToString(Record, 0, S))
2179        return Error("Invalid record");
2180      GCTable.push_back(S);
2181      break;
2182    }
2183    // GLOBALVAR: [pointer type, isconst, initid,
2184    //             linkage, alignment, section, visibility, threadlocal,
2185    //             unnamed_addr]
2186    case bitc::MODULE_CODE_GLOBALVAR: {
2187      if (Record.size() < 6)
2188        return Error("Invalid record");
2189      Type *Ty = getTypeByID(Record[0]);
2190      if (!Ty)
2191        return Error("Invalid record");
2192      if (!Ty->isPointerTy())
2193        return Error("Invalid type for value");
2194      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
2195      Ty = cast<PointerType>(Ty)->getElementType();
2196
2197      bool isConstant = Record[1];
2198      uint64_t RawLinkage = Record[3];
2199      GlobalValue::LinkageTypes Linkage = getDecodedLinkage(RawLinkage);
2200      unsigned Alignment = (1 << Record[4]) >> 1;
2201      std::string Section;
2202      if (Record[5]) {
2203        if (Record[5]-1 >= SectionTable.size())
2204          return Error("Invalid ID");
2205        Section = SectionTable[Record[5]-1];
2206      }
2207      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
2208      if (Record.size() > 6)
2209        Visibility = GetDecodedVisibility(Record[6]);
2210
2211      GlobalVariable::ThreadLocalMode TLM = GlobalVariable::NotThreadLocal;
2212      if (Record.size() > 7)
2213        TLM = GetDecodedThreadLocalMode(Record[7]);
2214
2215      bool UnnamedAddr = false;
2216      if (Record.size() > 8)
2217        UnnamedAddr = Record[8];
2218
2219      GlobalVariable *NewGV =
2220        new GlobalVariable(*TheModule, Ty, isConstant, Linkage, nullptr, "", nullptr,
2221                           TLM, AddressSpace);
2222      NewGV->setAlignment(Alignment);
2223      if (!Section.empty())
2224        NewGV->setSection(Section);
2225      NewGV->setVisibility(Visibility);
2226      NewGV->setUnnamedAddr(UnnamedAddr);
2227
2228      ValueList.push_back(NewGV);
2229
2230      // Remember which value to use for the global initializer.
2231      if (unsigned InitID = Record[2])
2232        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
2233      break;
2234    }
2235    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
2236    //             alignment, section, visibility, gc, unnamed_addr]
2237    case bitc::MODULE_CODE_FUNCTION: {
2238      if (Record.size() < 8)
2239        return Error("Invalid record");
2240      Type *Ty = getTypeByID(Record[0]);
2241      if (!Ty)
2242        return Error("Invalid record");
2243      if (!Ty->isPointerTy())
2244        return Error("Invalid type for value");
2245      FunctionType *FTy =
2246        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
2247      if (!FTy)
2248        return Error("Invalid type for value");
2249
2250      Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
2251                                        "", TheModule);
2252
2253      Func->setCallingConv(static_cast<CallingConv::ID>(Record[1]));
2254      bool isProto = Record[2];
2255      uint64_t RawLinkage = Record[3];
2256      Func->setLinkage(getDecodedLinkage(RawLinkage));
2257      Func->setAttributes(getAttributes(Record[4]));
2258
2259      Func->setAlignment((1 << Record[5]) >> 1);
2260      if (Record[6]) {
2261        if (Record[6]-1 >= SectionTable.size())
2262          return Error("Invalid ID");
2263        Func->setSection(SectionTable[Record[6]-1]);
2264      }
2265      Func->setVisibility(GetDecodedVisibility(Record[7]));
2266      if (Record.size() > 8 && Record[8]) {
2267        if (Record[8]-1 > GCTable.size())
2268          return Error("Invalid ID");
2269        Func->setGC(GCTable[Record[8]-1].c_str());
2270      }
2271      bool UnnamedAddr = false;
2272      if (Record.size() > 9)
2273        UnnamedAddr = Record[9];
2274      Func->setUnnamedAddr(UnnamedAddr);
2275      ValueList.push_back(Func);
2276
2277      // If this is a function with a body, remember the prototype we are
2278      // creating now, so that we can match up the body with them later.
2279      if (!isProto) {
2280        Func->setIsMaterializable(true);
2281        FunctionsWithBodies.push_back(Func);
2282        if (LazyStreamer)
2283          DeferredFunctionInfo[Func] = 0;
2284      }
2285      break;
2286    }
2287    // ALIAS: [alias type, aliasee val#, linkage]
2288    // ALIAS: [alias type, aliasee val#, linkage, visibility]
2289    case bitc::MODULE_CODE_ALIAS: {
2290      if (Record.size() < 3)
2291        return Error("Invalid record");
2292      Type *Ty = getTypeByID(Record[0]);
2293      if (!Ty)
2294        return Error("Invalid record");
2295      auto *PTy = dyn_cast<PointerType>(Ty);
2296      if (!PTy)
2297        return Error("Invalid type for value");
2298
2299      auto *NewGA =
2300          GlobalAlias::create(PTy->getElementType(), PTy->getAddressSpace(),
2301                              getDecodedLinkage(Record[2]), "", TheModule);
2302      // Old bitcode files didn't have visibility field.
2303      if (Record.size() > 3)
2304        NewGA->setVisibility(GetDecodedVisibility(Record[3]));
2305      ValueList.push_back(NewGA);
2306      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
2307      break;
2308    }
2309    /// MODULE_CODE_PURGEVALS: [numvals]
2310    case bitc::MODULE_CODE_PURGEVALS:
2311      // Trim down the value list to the specified size.
2312      if (Record.size() < 1 || Record[0] > ValueList.size())
2313        return Error("Invalid record");
2314      ValueList.shrinkTo(Record[0]);
2315      break;
2316    }
2317    Record.clear();
2318  }
2319
2320  return Error("Invalid bitcode signature");
2321}
2322
2323std::error_code BitcodeReader::ParseBitcodeInto(Module *M) {
2324  TheModule = nullptr;
2325
2326  if (std::error_code EC = InitStream())
2327    return EC;
2328
2329  // Sniff for the signature.
2330  if (Stream.Read(8) != 'B' ||
2331      Stream.Read(8) != 'C' ||
2332      Stream.Read(4) != 0x0 ||
2333      Stream.Read(4) != 0xC ||
2334      Stream.Read(4) != 0xE ||
2335      Stream.Read(4) != 0xD)
2336    return Error("Invalid bitcode signature");
2337
2338  // We expect a number of well-defined blocks, though we don't necessarily
2339  // need to understand them all.
2340  while (1) {
2341    if (Stream.AtEndOfStream())
2342      return std::error_code();
2343
2344    BitstreamEntry Entry =
2345      Stream.advance(BitstreamCursor::AF_DontAutoprocessAbbrevs);
2346
2347    switch (Entry.Kind) {
2348    case BitstreamEntry::Error:
2349      return Error("Malformed block");
2350    case BitstreamEntry::EndBlock:
2351      return std::error_code();
2352
2353    case BitstreamEntry::SubBlock:
2354      switch (Entry.ID) {
2355      case bitc::BLOCKINFO_BLOCK_ID:
2356        if (Stream.ReadBlockInfoBlock())
2357          return Error("Malformed block");
2358        break;
2359      case bitc::MODULE_BLOCK_ID:
2360        // Reject multiple MODULE_BLOCK's in a single bitstream.
2361        if (TheModule)
2362          return Error("Invalid multiple blocks");
2363        TheModule = M;
2364        if (std::error_code EC = ParseModule(false))
2365          return EC;
2366        if (LazyStreamer)
2367          return std::error_code();
2368        break;
2369      default:
2370        if (Stream.SkipBlock())
2371          return Error("Invalid record");
2372        break;
2373      }
2374      continue;
2375    case BitstreamEntry::Record:
2376      // There should be no records in the top-level of blocks.
2377
2378      // The ranlib in Xcode 4 will align archive members by appending newlines
2379      // to the end of them. If this file size is a multiple of 4 but not 8, we
2380      // have to read and ignore these final 4 bytes :-(
2381      if (Stream.getAbbrevIDWidth() == 2 && Entry.ID == 2 &&
2382          Stream.Read(6) == 2 && Stream.Read(24) == 0xa0a0a &&
2383          Stream.AtEndOfStream())
2384        return std::error_code();
2385
2386      return Error("Invalid record");
2387    }
2388  }
2389}
2390
2391llvm::ErrorOr<std::string> BitcodeReader::parseModuleTriple() {
2392  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
2393    return Error("Invalid record");
2394
2395  SmallVector<uint64_t, 64> Record;
2396
2397  std::string Triple;
2398  // Read all the records for this module.
2399  while (1) {
2400    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
2401
2402    switch (Entry.Kind) {
2403    case BitstreamEntry::SubBlock: // Handled for us already.
2404    case BitstreamEntry::Error:
2405      return Error("Malformed block");
2406    case BitstreamEntry::EndBlock:
2407      return Triple;
2408    case BitstreamEntry::Record:
2409      // The interesting case.
2410      break;
2411    }
2412
2413    // Read a record.
2414    switch (Stream.readRecord(Entry.ID, Record)) {
2415    default: break;  // Default behavior, ignore unknown content.
2416    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
2417      if (Record.size() < 1)
2418        return Error("Invalid record");
2419      // Only version #0 is supported so far.
2420      if (Record[0] != 0)
2421        return Error("Invalid record");
2422      break;
2423    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
2424      std::string S;
2425      if (ConvertToString(Record, 0, S))
2426        return Error("Invalid record");
2427      Triple = S;
2428      break;
2429    }
2430    }
2431    Record.clear();
2432  }
2433
2434  return Error("Invalid bitcode signature");
2435}
2436
2437llvm::ErrorOr<std::string> BitcodeReader::parseTriple() {
2438  if (std::error_code EC = InitStream())
2439    return EC;
2440
2441  // Sniff for the signature.
2442  if (Stream.Read(8) != 'B' ||
2443      Stream.Read(8) != 'C' ||
2444      Stream.Read(4) != 0x0 ||
2445      Stream.Read(4) != 0xC ||
2446      Stream.Read(4) != 0xE ||
2447      Stream.Read(4) != 0xD)
2448    return Error("Invalid bitcode signature");
2449
2450  // We expect a number of well-defined blocks, though we don't necessarily
2451  // need to understand them all.
2452  while (1) {
2453    BitstreamEntry Entry = Stream.advance();
2454
2455    switch (Entry.Kind) {
2456    case BitstreamEntry::Error:
2457      return Error("Malformed block");
2458    case BitstreamEntry::EndBlock:
2459      return std::error_code();
2460
2461    case BitstreamEntry::SubBlock:
2462      if (Entry.ID == bitc::MODULE_BLOCK_ID)
2463        return parseModuleTriple();
2464
2465      // Ignore other sub-blocks.
2466      if (Stream.SkipBlock())
2467        return Error("Malformed block");
2468      continue;
2469
2470    case BitstreamEntry::Record:
2471      Stream.skipRecord(Entry.ID);
2472      continue;
2473    }
2474  }
2475}
2476
2477/// ParseMetadataAttachment - Parse metadata attachments.
2478std::error_code BitcodeReader::ParseMetadataAttachment() {
2479  if (Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
2480    return Error("Invalid record");
2481
2482  SmallVector<uint64_t, 64> Record;
2483  while (1) {
2484    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
2485
2486    switch (Entry.Kind) {
2487    case BitstreamEntry::SubBlock: // Handled for us already.
2488    case BitstreamEntry::Error:
2489      return Error("Malformed block");
2490    case BitstreamEntry::EndBlock:
2491      return std::error_code();
2492    case BitstreamEntry::Record:
2493      // The interesting case.
2494      break;
2495    }
2496
2497    // Read a metadata attachment record.
2498    Record.clear();
2499    switch (Stream.readRecord(Entry.ID, Record)) {
2500    default:  // Default behavior: ignore.
2501      break;
2502    case METADATA_ATTACHMENT_2_7:
2503      LLVM2_7MetadataDetected = true;
2504    case bitc::METADATA_ATTACHMENT: {
2505      unsigned RecordLength = Record.size();
2506      if (Record.empty() || (RecordLength - 1) % 2 == 1)
2507        return Error("Invalid record");
2508      Instruction *Inst = InstructionList[Record[0]];
2509      for (unsigned i = 1; i != RecordLength; i = i+2) {
2510        unsigned Kind = Record[i];
2511        DenseMap<unsigned, unsigned>::iterator I =
2512          MDKindMap.find(Kind);
2513        if (I == MDKindMap.end())
2514          return Error("Invalid ID");
2515        Metadata *Node = MDValueList.getValueFwdRef(Record[i + 1]);
2516        Inst->setMetadata(I->second, cast<MDNode>(Node));
2517      }
2518      break;
2519    }
2520    }
2521  }
2522}
2523
2524/// ParseFunctionBody - Lazily parse the specified function body block.
2525std::error_code BitcodeReader::ParseFunctionBody(Function *F) {
2526  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
2527    return Error("Invalid record");
2528
2529  InstructionList.clear();
2530  unsigned ModuleValueListSize = ValueList.size();
2531  unsigned ModuleMDValueListSize = MDValueList.size();
2532
2533  // Add all the function arguments to the value table.
2534  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
2535    ValueList.push_back(I);
2536
2537  unsigned NextValueNo = ValueList.size();
2538  BasicBlock *CurBB = nullptr;
2539  unsigned CurBBNo = 0;
2540
2541  DebugLoc LastLoc;
2542
2543  // Read all the records.
2544  SmallVector<uint64_t, 64> Record;
2545  while (1) {
2546    unsigned Code = Stream.ReadCode();
2547    if (Code == bitc::END_BLOCK) {
2548      if (Stream.ReadBlockEnd())
2549        return Error("Malformed block");
2550      break;
2551    }
2552
2553    if (Code == bitc::ENTER_SUBBLOCK) {
2554      switch (Stream.ReadSubBlockID()) {
2555      default:  // Skip unknown content.
2556        if (Stream.SkipBlock())
2557          return Error("Invalid record");
2558        break;
2559      case bitc::CONSTANTS_BLOCK_ID:
2560        if (std::error_code EC = ParseConstants())
2561          return EC;
2562        NextValueNo = ValueList.size();
2563        break;
2564      case bitc::VALUE_SYMTAB_BLOCK_ID:
2565        if (std::error_code EC = ParseValueSymbolTable())
2566          return EC;
2567        break;
2568      case bitc::METADATA_ATTACHMENT_ID:
2569        if (std::error_code EC = ParseMetadataAttachment())
2570          return EC;
2571        break;
2572      case bitc::METADATA_BLOCK_ID:
2573        if (std::error_code EC = ParseMetadata())
2574          return EC;
2575        break;
2576      }
2577      continue;
2578    }
2579
2580    if (Code == bitc::DEFINE_ABBREV) {
2581      Stream.ReadAbbrevRecord();
2582      continue;
2583    }
2584
2585    // Read a record.
2586    Record.clear();
2587    Instruction *I = nullptr;
2588    unsigned BitCode = Stream.readRecord(Code, Record);
2589    switch (BitCode) {
2590    default: // Default behavior: reject
2591      return Error("Invalid value");
2592    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
2593      if (Record.size() < 1 || Record[0] == 0)
2594        return Error("Invalid record");
2595      // Create all the basic blocks for the function.
2596      FunctionBBs.resize(Record[0]);
2597      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
2598        FunctionBBs[i] = BasicBlock::Create(Context, "", F);
2599      CurBB = FunctionBBs[0];
2600      continue;
2601
2602    case bitc::FUNC_CODE_DEBUG_LOC_AGAIN:  // DEBUG_LOC_AGAIN
2603      // This record indicates that the last instruction is at the same
2604      // location as the previous instruction with a location.
2605      I = nullptr;
2606
2607      // Get the last instruction emitted.
2608      if (CurBB && !CurBB->empty())
2609        I = &CurBB->back();
2610      else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
2611               !FunctionBBs[CurBBNo-1]->empty())
2612        I = &FunctionBBs[CurBBNo-1]->back();
2613
2614      if (!I)
2615        return Error("Invalid record");
2616      I->setDebugLoc(LastLoc);
2617      I = nullptr;
2618      continue;
2619
2620    case FUNC_CODE_DEBUG_LOC_2_7:
2621      LLVM2_7MetadataDetected = true;
2622    case bitc::FUNC_CODE_DEBUG_LOC: {      // DEBUG_LOC: [line, col, scope, ia]
2623      I = nullptr;     // Get the last instruction emitted.
2624      if (CurBB && !CurBB->empty())
2625        I = &CurBB->back();
2626      else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
2627               !FunctionBBs[CurBBNo-1]->empty())
2628        I = &FunctionBBs[CurBBNo-1]->back();
2629      if (!I || Record.size() < 4)
2630        return Error("Invalid record");
2631
2632      unsigned Line = Record[0], Col = Record[1];
2633      unsigned ScopeID = Record[2], IAID = Record[3];
2634
2635      MDNode *Scope = nullptr, *IA = nullptr;
2636      if (ScopeID) Scope = cast<MDNode>(MDValueList.getValueFwdRef(ScopeID-1));
2637      if (IAID)    IA = cast<MDNode>(MDValueList.getValueFwdRef(IAID-1));
2638      LastLoc = DebugLoc::get(Line, Col, Scope, IA);
2639      I->setDebugLoc(LastLoc);
2640      I = nullptr;
2641      continue;
2642    }
2643
2644    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
2645      unsigned OpNum = 0;
2646      Value *LHS, *RHS;
2647      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
2648          getValue(Record, OpNum, LHS->getType(), RHS) ||
2649          OpNum+1 > Record.size())
2650        return Error("Invalid record");
2651
2652      int Opc = GetDecodedBinaryOpcode(Record[OpNum++], LHS->getType());
2653      if (Opc == -1)
2654        return Error("Invalid record");
2655      I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
2656      InstructionList.push_back(I);
2657      if (OpNum < Record.size()) {
2658        if (Opc == Instruction::Add ||
2659            Opc == Instruction::Sub ||
2660            Opc == Instruction::Mul ||
2661            Opc == Instruction::Shl) {
2662          if (Record[OpNum] & (1 << bitc::OBO_NO_SIGNED_WRAP))
2663            cast<BinaryOperator>(I)->setHasNoSignedWrap(true);
2664          if (Record[OpNum] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
2665            cast<BinaryOperator>(I)->setHasNoUnsignedWrap(true);
2666        } else if (Opc == Instruction::SDiv ||
2667                   Opc == Instruction::UDiv ||
2668                   Opc == Instruction::LShr ||
2669                   Opc == Instruction::AShr) {
2670          if (Record[OpNum] & (1 << bitc::PEO_EXACT))
2671            cast<BinaryOperator>(I)->setIsExact(true);
2672        }
2673      }
2674      break;
2675    }
2676    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
2677      unsigned OpNum = 0;
2678      Value *Op;
2679      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2680          OpNum+2 != Record.size())
2681        return Error("Invalid record");
2682
2683      Type *ResTy = getTypeByID(Record[OpNum]);
2684      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
2685      if (Opc == -1 || !ResTy)
2686        return Error("Invalid record");
2687      I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
2688      InstructionList.push_back(I);
2689      break;
2690    }
2691    case bitc::FUNC_CODE_INST_INBOUNDS_GEP_OLD:
2692    case bitc::FUNC_CODE_INST_GEP_OLD: // GEP: [n x operands]
2693    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
2694      unsigned OpNum = 0;
2695
2696      Type *Ty;
2697      bool InBounds;
2698
2699      if (BitCode == bitc::FUNC_CODE_INST_GEP) {
2700        InBounds = Record[OpNum++];
2701        Ty = getTypeByID(Record[OpNum++]);
2702      } else {
2703        InBounds = BitCode == bitc::FUNC_CODE_INST_INBOUNDS_GEP_OLD;
2704        Ty = nullptr;
2705      }
2706
2707      Value *BasePtr;
2708      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
2709        return Error("Invalid record");
2710
2711      if (Ty &&
2712          Ty !=
2713              cast<SequentialType>(BasePtr->getType()->getScalarType())
2714                  ->getElementType())
2715        return Error(
2716            "Explicit gep type does not match pointee type of pointer operand");
2717
2718      SmallVector<Value*, 16> GEPIdx;
2719      while (OpNum != Record.size()) {
2720        Value *Op;
2721        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2722          return Error("Invalid record");
2723        GEPIdx.push_back(Op);
2724      }
2725
2726      I = GetElementPtrInst::Create(Ty, BasePtr, GEPIdx);
2727
2728      InstructionList.push_back(I);
2729      if (InBounds)
2730        cast<GetElementPtrInst>(I)->setIsInBounds(true);
2731      break;
2732    }
2733
2734    case bitc::FUNC_CODE_INST_EXTRACTVAL: {
2735                                       // EXTRACTVAL: [opty, opval, n x indices]
2736      unsigned OpNum = 0;
2737      Value *Agg;
2738      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2739        return Error("Invalid record");
2740
2741      SmallVector<unsigned, 4> EXTRACTVALIdx;
2742      for (unsigned RecSize = Record.size();
2743           OpNum != RecSize; ++OpNum) {
2744        uint64_t Index = Record[OpNum];
2745        if ((unsigned)Index != Index)
2746          return Error("Invalid value");
2747        EXTRACTVALIdx.push_back((unsigned)Index);
2748      }
2749
2750      I = ExtractValueInst::Create(Agg, EXTRACTVALIdx);
2751      InstructionList.push_back(I);
2752      break;
2753    }
2754
2755    case bitc::FUNC_CODE_INST_INSERTVAL: {
2756                           // INSERTVAL: [opty, opval, opty, opval, n x indices]
2757      unsigned OpNum = 0;
2758      Value *Agg;
2759      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2760        return Error("Invalid record");
2761      Value *Val;
2762      if (getValueTypePair(Record, OpNum, NextValueNo, Val))
2763        return Error("Invalid record");
2764
2765      SmallVector<unsigned, 4> INSERTVALIdx;
2766      for (unsigned RecSize = Record.size();
2767           OpNum != RecSize; ++OpNum) {
2768        uint64_t Index = Record[OpNum];
2769        if ((unsigned)Index != Index)
2770          return Error("Invalid value");
2771        INSERTVALIdx.push_back((unsigned)Index);
2772      }
2773
2774      I = InsertValueInst::Create(Agg, Val, INSERTVALIdx);
2775      InstructionList.push_back(I);
2776      break;
2777    }
2778
2779    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
2780      // obsolete form of select
2781      // handles select i1 ... in old bitcode
2782      unsigned OpNum = 0;
2783      Value *TrueVal, *FalseVal, *Cond;
2784      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2785          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
2786          getValue(Record, OpNum, Type::getInt1Ty(Context), Cond))
2787        return Error("Invalid record");
2788
2789      I = SelectInst::Create(Cond, TrueVal, FalseVal);
2790      InstructionList.push_back(I);
2791      break;
2792    }
2793
2794    case bitc::FUNC_CODE_INST_VSELECT: {// VSELECT: [ty,opval,opval,predty,pred]
2795      // new form of select
2796      // handles select i1 or select [N x i1]
2797      unsigned OpNum = 0;
2798      Value *TrueVal, *FalseVal, *Cond;
2799      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2800          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
2801          getValueTypePair(Record, OpNum, NextValueNo, Cond))
2802        return Error("Invalid record");
2803
2804      // select condition can be either i1 or [N x i1]
2805      if (VectorType* vector_type =
2806          dyn_cast<VectorType>(Cond->getType())) {
2807        // expect <n x i1>
2808        if (vector_type->getElementType() != Type::getInt1Ty(Context))
2809          return Error("Invalid type for value");
2810      } else {
2811        // expect i1
2812        if (Cond->getType() != Type::getInt1Ty(Context))
2813          return Error("Invalid type for value");
2814      }
2815
2816      I = SelectInst::Create(Cond, TrueVal, FalseVal);
2817      InstructionList.push_back(I);
2818      break;
2819    }
2820
2821    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
2822      unsigned OpNum = 0;
2823      Value *Vec, *Idx;
2824      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2825          getValue(Record, OpNum, Type::getInt32Ty(Context), Idx))
2826        return Error("Invalid record");
2827      I = ExtractElementInst::Create(Vec, Idx);
2828      InstructionList.push_back(I);
2829      break;
2830    }
2831
2832    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
2833      unsigned OpNum = 0;
2834      Value *Vec, *Elt, *Idx;
2835      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2836          getValue(Record, OpNum,
2837                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
2838          getValue(Record, OpNum, Type::getInt32Ty(Context), Idx))
2839        return Error("Invalid record");
2840      I = InsertElementInst::Create(Vec, Elt, Idx);
2841      InstructionList.push_back(I);
2842      break;
2843    }
2844
2845    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
2846      unsigned OpNum = 0;
2847      Value *Vec1, *Vec2, *Mask;
2848      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
2849          getValue(Record, OpNum, Vec1->getType(), Vec2))
2850        return Error("Invalid record");
2851
2852      if (getValueTypePair(Record, OpNum, NextValueNo, Mask))
2853        return Error("Invalid record");
2854      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
2855      InstructionList.push_back(I);
2856      break;
2857    }
2858
2859    case bitc::FUNC_CODE_INST_CMP:   // CMP: [opty, opval, opval, pred]
2860      // Old form of ICmp/FCmp returning bool
2861      // Existed to differentiate between icmp/fcmp and vicmp/vfcmp which were
2862      // both legal on vectors but had different behaviour.
2863    case bitc::FUNC_CODE_INST_CMP2: { // CMP2: [opty, opval, opval, pred]
2864      // FCmp/ICmp returning bool or vector of bool
2865
2866      unsigned OpNum = 0;
2867      Value *LHS, *RHS;
2868      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
2869          getValue(Record, OpNum, LHS->getType(), RHS) ||
2870          OpNum+1 != Record.size())
2871        return Error("Invalid record");
2872
2873      if (LHS->getType()->isFPOrFPVectorTy())
2874        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
2875      else
2876        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
2877      InstructionList.push_back(I);
2878      break;
2879    }
2880
2881    case FUNC_CODE_INST_GETRESULT_2_7: {
2882      if (Record.size() != 2) {
2883        return Error("Invalid record");
2884      }
2885      unsigned OpNum = 0;
2886      Value *Op;
2887      getValueTypePair(Record, OpNum, NextValueNo, Op);
2888      unsigned Index = Record[1];
2889      I = ExtractValueInst::Create(Op, Index);
2890      InstructionList.push_back(I);
2891      break;
2892    }
2893
2894    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
2895      {
2896        unsigned Size = Record.size();
2897        if (Size == 0) {
2898          I = ReturnInst::Create(Context);
2899          InstructionList.push_back(I);
2900          break;
2901        }
2902
2903        unsigned OpNum = 0;
2904        Value *Op = nullptr;
2905        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2906          return Error("Invalid record");
2907        if (OpNum != Record.size())
2908          return Error("Invalid record");
2909
2910        I = ReturnInst::Create(Context, Op);
2911        InstructionList.push_back(I);
2912        break;
2913      }
2914    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
2915      if (Record.size() != 1 && Record.size() != 3)
2916        return Error("Invalid record");
2917      BasicBlock *TrueDest = getBasicBlock(Record[0]);
2918      if (!TrueDest)
2919        return Error("Invalid record");
2920
2921      if (Record.size() == 1) {
2922        I = BranchInst::Create(TrueDest);
2923        InstructionList.push_back(I);
2924      }
2925      else {
2926        BasicBlock *FalseDest = getBasicBlock(Record[1]);
2927        Value *Cond = getFnValueByID(Record[2], Type::getInt1Ty(Context));
2928        if (!FalseDest || !Cond)
2929          return Error("Invalid record");
2930        I = BranchInst::Create(TrueDest, FalseDest, Cond);
2931        InstructionList.push_back(I);
2932      }
2933      break;
2934    }
2935    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, op0, op1, ...]
2936      if (Record.size() < 3 || (Record.size() & 1) == 0)
2937        return Error("Invalid record");
2938      Type *OpTy = getTypeByID(Record[0]);
2939      Value *Cond = getFnValueByID(Record[1], OpTy);
2940      BasicBlock *Default = getBasicBlock(Record[2]);
2941      if (!OpTy || !Cond || !Default)
2942        return Error("Invalid record");
2943      unsigned NumCases = (Record.size()-3)/2;
2944      SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
2945      InstructionList.push_back(SI);
2946      for (unsigned i = 0, e = NumCases; i != e; ++i) {
2947        ConstantInt *CaseVal =
2948          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
2949        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
2950        if (!CaseVal || !DestBB) {
2951          delete SI;
2952          return Error("Invalid record");
2953        }
2954        SI->addCase(CaseVal, DestBB);
2955      }
2956      I = SI;
2957      break;
2958    }
2959    case bitc::FUNC_CODE_INST_INDIRECTBR: { // INDIRECTBR: [opty, op0, op1, ...]
2960      if (Record.size() < 2)
2961        return Error("Invalid record");
2962      Type *OpTy = getTypeByID(Record[0]);
2963      Value *Address = getFnValueByID(Record[1], OpTy);
2964      if (!OpTy || !Address)
2965        return Error("Invalid record");
2966      unsigned NumDests = Record.size()-2;
2967      IndirectBrInst *IBI = IndirectBrInst::Create(Address, NumDests);
2968      InstructionList.push_back(IBI);
2969      for (unsigned i = 0, e = NumDests; i != e; ++i) {
2970        if (BasicBlock *DestBB = getBasicBlock(Record[2+i])) {
2971          IBI->addDestination(DestBB);
2972        } else {
2973          delete IBI;
2974          return Error("Invalid record");
2975        }
2976      }
2977      I = IBI;
2978      break;
2979    }
2980
2981    case bitc::FUNC_CODE_INST_INVOKE: {
2982      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
2983      if (Record.size() < 4)
2984        return Error("Invalid record");
2985      AttributeSet PAL = getAttributes(Record[0]);
2986      unsigned CCInfo = Record[1];
2987      BasicBlock *NormalBB = getBasicBlock(Record[2]);
2988      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
2989
2990      unsigned OpNum = 4;
2991      Value *Callee;
2992      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
2993        return Error("Invalid record");
2994
2995      PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
2996      FunctionType *FTy = !CalleeTy ? nullptr :
2997        dyn_cast<FunctionType>(CalleeTy->getElementType());
2998
2999      // Check that the right number of fixed parameters are here.
3000      if (!FTy || !NormalBB || !UnwindBB ||
3001          Record.size() < OpNum+FTy->getNumParams())
3002        return Error("Invalid record");
3003
3004      SmallVector<Value*, 16> Ops;
3005      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
3006        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
3007        if (!Ops.back())
3008          return Error("Invalid record");
3009      }
3010
3011      if (!FTy->isVarArg()) {
3012        if (Record.size() != OpNum)
3013          return Error("Invalid record");
3014      } else {
3015        // Read type/value pairs for varargs params.
3016        while (OpNum != Record.size()) {
3017          Value *Op;
3018          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
3019            return Error("Invalid record");
3020          Ops.push_back(Op);
3021        }
3022      }
3023
3024      I = InvokeInst::Create(Callee, NormalBB, UnwindBB, Ops);
3025      InstructionList.push_back(I);
3026      cast<InvokeInst>(I)->setCallingConv(
3027        static_cast<CallingConv::ID>(CCInfo));
3028      cast<InvokeInst>(I)->setAttributes(PAL);
3029      break;
3030    }
3031    case FUNC_CODE_INST_UNWIND_2_7: { // UNWIND_OLD
3032      // 'unwind' instruction has been removed in LLVM 3.1
3033      // Replace 'unwind' with 'landingpad' and 'resume'.
3034      Type *ExnTy = StructType::get(Type::getInt8PtrTy(Context),
3035                                    Type::getInt32Ty(Context), nullptr);
3036      Constant *PersFn =
3037        F->getParent()->
3038        getOrInsertFunction("__gcc_personality_v0",
3039                          FunctionType::get(Type::getInt32Ty(Context), true));
3040
3041      LandingPadInst *LP = LandingPadInst::Create(ExnTy, PersFn, 1);
3042      LP->setCleanup(true);
3043
3044      CurBB->getInstList().push_back(LP);
3045      I = ResumeInst::Create(LP);
3046      InstructionList.push_back(I);
3047      break;
3048    }
3049    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
3050      I = new UnreachableInst(Context);
3051      InstructionList.push_back(I);
3052      break;
3053    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
3054      if (Record.size() < 1 || ((Record.size()-1)&1))
3055        return Error("Invalid record");
3056      Type *Ty = getTypeByID(Record[0]);
3057      if (!Ty)
3058        return Error("Invalid record");
3059
3060      PHINode *PN = PHINode::Create(Ty, (Record.size()-1)/2);
3061      InstructionList.push_back(PN);
3062
3063      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
3064        Value *V = getFnValueByID(Record[1+i], Ty);
3065        BasicBlock *BB = getBasicBlock(Record[2+i]);
3066        if (!V || !BB)
3067          return Error("Invalid record");
3068        PN->addIncoming(V, BB);
3069      }
3070      I = PN;
3071      break;
3072    }
3073
3074    case FUNC_CODE_INST_MALLOC_2_7: { // MALLOC: [instty, op, align]
3075      // Autoupgrade malloc instruction to malloc call.
3076      // FIXME: Remove in LLVM 3.0.
3077      if (Record.size() < 3) {
3078        return Error("Invalid record");
3079      }
3080      PointerType *Ty =
3081          dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
3082      Value *Size = getFnValueByID(Record[1], Type::getInt32Ty(Context));
3083      if (!Ty || !Size)
3084        return Error("Invalid record");
3085      if (!CurBB)
3086        return Error("Invalid instruction with no BB");
3087      Type *Int32Ty = IntegerType::getInt32Ty(CurBB->getContext());
3088      Constant *AllocSize = ConstantExpr::getSizeOf(Ty->getElementType());
3089      AllocSize = ConstantExpr::getTruncOrBitCast(AllocSize, Int32Ty);
3090      I = CallInst::CreateMalloc(CurBB, Int32Ty, Ty->getElementType(),
3091                                 AllocSize, Size, nullptr);
3092      InstructionList.push_back(I);
3093      break;
3094    }
3095    case FUNC_CODE_INST_FREE_2_7: { // FREE: [op, opty]
3096      unsigned OpNum = 0;
3097      Value *Op;
3098      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
3099          OpNum != Record.size()) {
3100        return Error("Invalid record");
3101      }
3102      if (!CurBB)
3103        return Error("Invalid instruction with no BB");
3104      I = CallInst::CreateFree(Op, CurBB);
3105      InstructionList.push_back(I);
3106      break;
3107    }
3108
3109    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, opty, op, align]
3110      // For backward compatibility, tolerate a lack of an opty, and use i32.
3111      // Remove this in LLVM 3.0.
3112      if (Record.size() < 3 || Record.size() > 4) {
3113        return Error("Invalid record");
3114      }
3115      unsigned OpNum = 0;
3116      PointerType *Ty =
3117        dyn_cast_or_null<PointerType>(getTypeByID(Record[OpNum++]));
3118      Type *OpTy = Record.size() == 4 ? getTypeByID(Record[OpNum++]) :
3119                                              Type::getInt32Ty(Context);
3120      Value *Size = getFnValueByID(Record[OpNum++], OpTy);
3121      unsigned Align = Record[OpNum++];
3122      if (!Ty || !Size)
3123        return Error("Invalid record");
3124      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
3125      InstructionList.push_back(I);
3126      break;
3127    }
3128    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
3129      unsigned OpNum = 0;
3130      Value *Op;
3131      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
3132          OpNum+2 != Record.size())
3133        return Error("Invalid record");
3134
3135      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
3136      InstructionList.push_back(I);
3137      break;
3138    }
3139    case bitc::FUNC_CODE_INST_STORE: { // STORE2:[ptrty, ptr, val, align, vol]
3140      unsigned OpNum = 0;
3141      Value *Val, *Ptr;
3142      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
3143          getValue(Record, OpNum,
3144                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
3145          OpNum+2 != Record.size())
3146        return Error("Invalid record");
3147
3148      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
3149      InstructionList.push_back(I);
3150      break;
3151    }
3152    case FUNC_CODE_INST_STORE_2_7: {
3153      unsigned OpNum = 0;
3154      Value *Val, *Ptr;
3155      if (getValueTypePair(Record, OpNum, NextValueNo, Val) ||
3156          getValue(Record, OpNum,
3157                   PointerType::getUnqual(Val->getType()), Ptr)||
3158          OpNum+2 != Record.size()) {
3159        return Error("Invalid record");
3160      }
3161      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
3162      InstructionList.push_back(I);
3163      break;
3164    }
3165    case FUNC_CODE_INST_CALL_2_7:
3166      LLVM2_7MetadataDetected = true;
3167    case bitc::FUNC_CODE_INST_CALL: {
3168      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
3169      if (Record.size() < 3)
3170        return Error("Invalid record");
3171
3172      AttributeSet PAL = getAttributes(Record[0]);
3173      unsigned CCInfo = Record[1];
3174
3175      unsigned OpNum = 2;
3176      Value *Callee;
3177      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
3178        return Error("Invalid record");
3179
3180      PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
3181      FunctionType *FTy = nullptr;
3182      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
3183      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
3184        return Error("Invalid record");
3185
3186      SmallVector<Value*, 16> Args;
3187      // Read the fixed params.
3188      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
3189        if (FTy->getParamType(i)->isLabelTy())
3190          Args.push_back(getBasicBlock(Record[OpNum]));
3191        else
3192          Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
3193        if (!Args.back())
3194          return Error("Invalid record");
3195      }
3196
3197      // Read type/value pairs for varargs params.
3198      if (!FTy->isVarArg()) {
3199        if (OpNum != Record.size())
3200          return Error("Invalid record");
3201      } else {
3202        while (OpNum != Record.size()) {
3203          Value *Op;
3204          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
3205            return Error("Invalid record");
3206          Args.push_back(Op);
3207        }
3208      }
3209
3210      I = CallInst::Create(Callee, Args);
3211      InstructionList.push_back(I);
3212      cast<CallInst>(I)->setCallingConv(
3213        static_cast<CallingConv::ID>(CCInfo>>1));
3214      cast<CallInst>(I)->setTailCall(CCInfo & 1);
3215      cast<CallInst>(I)->setAttributes(PAL);
3216      break;
3217    }
3218    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
3219      if (Record.size() < 3)
3220        return Error("Invalid record");
3221      Type *OpTy = getTypeByID(Record[0]);
3222      Value *Op = getFnValueByID(Record[1], OpTy);
3223      Type *ResTy = getTypeByID(Record[2]);
3224      if (!OpTy || !Op || !ResTy)
3225        return Error("Invalid record");
3226      I = new VAArgInst(Op, ResTy);
3227      InstructionList.push_back(I);
3228      break;
3229    }
3230    }
3231
3232    // Add instruction to end of current BB.  If there is no current BB, reject
3233    // this file.
3234    if (!CurBB) {
3235      delete I;
3236      return Error("Invalid instruction with no BB");
3237    }
3238    CurBB->getInstList().push_back(I);
3239
3240    // If this was a terminator instruction, move to the next block.
3241    if (isa<TerminatorInst>(I)) {
3242      ++CurBBNo;
3243      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : nullptr;
3244    }
3245
3246    // Non-void values get registered in the value table for future use.
3247    if (I && !I->getType()->isVoidTy())
3248      ValueList.AssignValue(I, NextValueNo++);
3249  }
3250
3251  // Check the function list for unresolved values.
3252  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
3253    if (!A->getParent()) {
3254      // We found at least one unresolved value.  Nuke them all to avoid leaks.
3255      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
3256        if ((A = dyn_cast_or_null<Argument>(ValueList[i])) && !A->getParent()) {
3257          A->replaceAllUsesWith(UndefValue::get(A->getType()));
3258          delete A;
3259        }
3260      }
3261      return Error("Never resolved value found in function");
3262    }
3263  }
3264
3265  // FIXME: Check for unresolved forward-declared metadata references
3266  // and clean up leaks.
3267
3268  // See if anything took the address of blocks in this function.  If so,
3269  // resolve them now.
3270  DenseMap<Function*, std::vector<BlockAddrRefTy> >::iterator BAFRI =
3271    BlockAddrFwdRefs.find(F);
3272  if (BAFRI != BlockAddrFwdRefs.end()) {
3273    std::vector<BlockAddrRefTy> &RefList = BAFRI->second;
3274    for (unsigned i = 0, e = RefList.size(); i != e; ++i) {
3275      unsigned BlockIdx = RefList[i].first;
3276      if (BlockIdx >= FunctionBBs.size())
3277        return Error("Invalid ID");
3278
3279      GlobalVariable *FwdRef = RefList[i].second;
3280      FwdRef->replaceAllUsesWith(BlockAddress::get(F, FunctionBBs[BlockIdx]));
3281      FwdRef->eraseFromParent();
3282    }
3283
3284    BlockAddrFwdRefs.erase(BAFRI);
3285  }
3286
3287  unsigned NewMDValueListSize = MDValueList.size();
3288  // Trim the value list down to the size it was before we parsed this function.
3289  ValueList.shrinkTo(ModuleValueListSize);
3290  MDValueList.shrinkTo(ModuleMDValueListSize);
3291
3292  if (LLVM2_7MetadataDetected) {
3293    MDValueList.resize(NewMDValueListSize);
3294  }
3295
3296  std::vector<BasicBlock*>().swap(FunctionBBs);
3297  return std::error_code();
3298}
3299
3300//===----------------------------------------------------------------------===//
3301// GVMaterializer implementation
3302//===----------------------------------------------------------------------===//
3303
3304void BitcodeReader::releaseBuffer() { Buffer.release(); }
3305
3306std::error_code BitcodeReader::materialize(GlobalValue *GV) {
3307  if (std::error_code EC = materializeMetadata())
3308    return EC;
3309
3310  Function *F = dyn_cast<Function>(GV);
3311  // If it's not a function or is already material, ignore the request.
3312  if (!F || !F->isMaterializable())
3313    return std::error_code();
3314
3315  DenseMap<Function*, uint64_t>::iterator DFII = DeferredFunctionInfo.find(F);
3316  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
3317
3318  // Move the bit stream to the saved position of the deferred function body.
3319  Stream.JumpToBit(DFII->second);
3320
3321  if (std::error_code EC = ParseFunctionBody(F))
3322    return EC;
3323  F->setIsMaterializable(false);
3324
3325  // Upgrade any old intrinsic calls in the function.
3326  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
3327       E = UpgradedIntrinsics.end(); I != E; ++I) {
3328    if (I->first != I->second) {
3329      for (auto UI = I->first->user_begin(), UE = I->first->user_end();
3330           UI != UE;) {
3331        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
3332          UpgradeIntrinsicCall(CI, I->second);
3333      }
3334    }
3335  }
3336
3337  return std::error_code();
3338}
3339
3340bool BitcodeReader::isDematerializable(const GlobalValue *GV) const {
3341  const Function *F = dyn_cast<Function>(GV);
3342  if (!F || F->isDeclaration())
3343    return false;
3344  return DeferredFunctionInfo.count(const_cast<Function*>(F));
3345}
3346
3347void BitcodeReader::Dematerialize(GlobalValue *GV) {
3348  Function *F = dyn_cast<Function>(GV);
3349  // If this function isn't dematerializable, this is a noop.
3350  if (!F || !isDematerializable(F))
3351    return;
3352
3353  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
3354
3355  // Just forget the function body, we can remat it later.
3356  F->deleteBody();
3357  F->setIsMaterializable(true);
3358}
3359
3360std::error_code BitcodeReader::MaterializeModule(Module *M) {
3361  assert(M == TheModule &&
3362         "Can only Materialize the Module this BitcodeReader is attached to.");
3363  // Iterate over the module, deserializing any functions that are still on
3364  // disk.
3365  for (Module::iterator F = TheModule->begin(), E = TheModule->end();
3366       F != E; ++F) {
3367    if (std::error_code EC = materialize(F))
3368      return EC;
3369  }
3370  // At this point, if there are any function bodies, the current bit is
3371  // pointing to the END_BLOCK record after them. Now make sure the rest
3372  // of the bits in the module have been read.
3373  if (NextUnreadBit)
3374    ParseModule(true);
3375
3376  // Upgrade any intrinsic calls that slipped through (should not happen!) and
3377  // delete the old functions to clean up. We can't do this unless the entire
3378  // module is materialized because there could always be another function body
3379  // with calls to the old function.
3380  for (std::vector<std::pair<Function*, Function*> >::iterator I =
3381       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
3382    if (I->first != I->second) {
3383      for (auto UI = I->first->user_begin(), UE = I->first->user_end();
3384           UI != UE;) {
3385        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
3386          UpgradeIntrinsicCall(CI, I->second);
3387      }
3388      if (!I->first->use_empty())
3389        I->first->replaceAllUsesWith(I->second);
3390      I->first->eraseFromParent();
3391    }
3392  }
3393  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
3394
3395  // Check debug info intrinsics.
3396  CheckDebugInfoIntrinsics(TheModule);
3397
3398  return std::error_code();
3399}
3400
3401std::vector<StructType *> BitcodeReader::getIdentifiedStructTypes() const {
3402  return IdentifiedStructTypes;
3403}
3404
3405std::error_code BitcodeReader::InitStream() {
3406  if (LazyStreamer)
3407    return InitLazyStream();
3408  return InitStreamFromBuffer();
3409}
3410
3411std::error_code BitcodeReader::InitStreamFromBuffer() {
3412  const unsigned char *BufPtr = (const unsigned char*)Buffer->getBufferStart();
3413  const unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
3414
3415  if (Buffer->getBufferSize() & 3)
3416    return Error("Invalid bitcode signature");
3417
3418  // If we have a wrapper header, parse it and ignore the non-bc file contents.
3419  // The magic number is 0x0B17C0DE stored in little endian.
3420  if (isBitcodeWrapper(BufPtr, BufEnd))
3421    if (SkipBitcodeWrapperHeader(BufPtr, BufEnd, true))
3422      return Error("Invalid bitcode wrapper header");
3423
3424  StreamFile.reset(new BitstreamReader(BufPtr, BufEnd));
3425  Stream.init(&*StreamFile);
3426
3427  return std::error_code();
3428}
3429
3430std::error_code BitcodeReader::InitLazyStream() {
3431  // Check and strip off the bitcode wrapper; BitstreamReader expects never to
3432  // see it.
3433  auto OwnedBytes = llvm::make_unique<StreamingMemoryObject>(LazyStreamer);
3434  StreamingMemoryObject &Bytes = *OwnedBytes;
3435  StreamFile = llvm::make_unique<BitstreamReader>(std::move(OwnedBytes));
3436  Stream.init(&*StreamFile);
3437
3438  unsigned char buf[16];
3439  if (Bytes.readBytes(buf, 16, 0) != 16)
3440    return Error("Invalid bitcode signature");
3441
3442  if (!isBitcode(buf, buf + 16))
3443    return Error("Invalid bitcode signature");
3444
3445  if (isBitcodeWrapper(buf, buf + 4)) {
3446    const unsigned char *bitcodeStart = buf;
3447    const unsigned char *bitcodeEnd = buf + 16;
3448    SkipBitcodeWrapperHeader(bitcodeStart, bitcodeEnd, false);
3449    Bytes.dropLeadingBytes(bitcodeStart - buf);
3450    Bytes.setKnownObjectSize(bitcodeEnd - bitcodeStart);
3451  }
3452  return std::error_code();
3453}
3454
3455namespace {
3456class BitcodeErrorCategoryType : public std::error_category {
3457  const char *name() const LLVM_NOEXCEPT override {
3458    return "llvm.bitcode";
3459  }
3460  std::string message(int IE) const override {
3461    BitcodeError E = static_cast<BitcodeError>(IE);
3462    switch (E) {
3463    case BitcodeError::InvalidBitcodeSignature:
3464      return "Invalid bitcode signature";
3465    case BitcodeError::CorruptedBitcode:
3466      return "Corrupted bitcode";
3467    }
3468    llvm_unreachable("Unknown error type!");
3469  }
3470};
3471}
3472
3473static ManagedStatic<BitcodeErrorCategoryType> ErrorCategory;
3474
3475const std::error_category &BitcodeReader::BitcodeErrorCategory() {
3476  return *ErrorCategory;
3477}
3478
3479//===----------------------------------------------------------------------===//
3480// External interface
3481//===----------------------------------------------------------------------===//
3482
3483/// getLazyBitcodeModule - lazy function-at-a-time loading from a file.
3484///
3485static llvm::ErrorOr<llvm::Module *>
3486getLazyBitcodeModuleImpl(std::unique_ptr<MemoryBuffer> &&Buffer,
3487                         LLVMContext &Context, bool WillMaterializeAll,
3488                         DiagnosticHandlerFunction DiagnosticHandler) {
3489  Module *M = new Module(Buffer->getBufferIdentifier(), Context);
3490  BitcodeReader *R =
3491      new BitcodeReader(Buffer.get(), Context, DiagnosticHandler);
3492  M->setMaterializer(R);
3493
3494  auto cleanupOnError = [&](std::error_code EC) {
3495    R->releaseBuffer(); // Never take ownership on error.
3496    delete M;  // Also deletes R.
3497    return EC;
3498  };
3499
3500  if (std::error_code EC = R->ParseBitcodeInto(M))
3501    return cleanupOnError(EC);
3502
3503  Buffer.release(); // The BitcodeReader owns it now.
3504  return M;
3505}
3506
3507llvm::ErrorOr<Module *>
3508llvm_2_7::getLazyBitcodeModule(std::unique_ptr<MemoryBuffer> &&Buffer,
3509                           LLVMContext &Context,
3510                           DiagnosticHandlerFunction DiagnosticHandler) {
3511  return getLazyBitcodeModuleImpl(std::move(Buffer), Context, false,
3512                                  DiagnosticHandler);
3513}
3514
3515/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
3516/// If an error occurs, return null and fill in *ErrMsg if non-null.
3517llvm::ErrorOr<llvm::Module *>
3518llvm_2_7::parseBitcodeFile(MemoryBufferRef Buffer, LLVMContext &Context,
3519                       DiagnosticHandlerFunction DiagnosticHandler) {
3520  std::unique_ptr<MemoryBuffer> Buf = MemoryBuffer::getMemBuffer(Buffer, false);
3521  ErrorOr<Module *> ModuleOrErr = getLazyBitcodeModuleImpl(
3522      std::move(Buf), Context, true, DiagnosticHandler);
3523  if (!ModuleOrErr)
3524    return ModuleOrErr;
3525  Module *M = ModuleOrErr.get();
3526  // Read in the entire module, and destroy the BitcodeReader.
3527  if (std::error_code EC = M->materializeAllPermanently()) {
3528    delete M;
3529    return EC;
3530  }
3531
3532  return M;
3533}
3534
3535std::string
3536llvm_2_7::getBitcodeTargetTriple(MemoryBufferRef Buffer, LLVMContext &Context,
3537                             DiagnosticHandlerFunction DiagnosticHandler) {
3538  std::unique_ptr<MemoryBuffer> Buf = MemoryBuffer::getMemBuffer(Buffer, false);
3539  auto R = llvm::make_unique<BitcodeReader>(Buf.release(), Context,
3540                                            DiagnosticHandler);
3541  ErrorOr<std::string> Triple = R->parseTriple();
3542  if (Triple.getError())
3543    return "";
3544  return Triple.get();
3545}
3546