BitcodeReader.cpp revision 006c7b969a04403f1b5fb39971f14af6f2405b5a 
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 "BitcodeReader.h"
16#include "llvm/Constants.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/InlineAsm.h"
19#include "llvm/IntrinsicInst.h"
20#include "llvm/Module.h"
21#include "llvm/Operator.h"
22#include "llvm/AutoUpgrade.h"
23#include "llvm/ADT/SmallString.h"
24#include "llvm/ADT/SmallVector.h"
25#include "llvm/Support/DataStream.h"
26#include "llvm/Support/MathExtras.h"
27#include "llvm/Support/MemoryBuffer.h"
28#include "llvm/OperandTraits.h"
29using namespace llvm;
30
31void BitcodeReader::materializeForwardReferencedFunctions() {
32  while (!BlockAddrFwdRefs.empty()) {
33    Function *F = BlockAddrFwdRefs.begin()->first;
34    F->Materialize();
35  }
36}
37
38void BitcodeReader::FreeState() {
39  if (BufferOwned)
40    delete Buffer;
41  Buffer = 0;
42  std::vector<Type*>().swap(TypeList);
43  ValueList.clear();
44  MDValueList.clear();
45
46  std::vector<AttrListPtr>().swap(MAttributes);
47  std::vector<BasicBlock*>().swap(FunctionBBs);
48  std::vector<Function*>().swap(FunctionsWithBodies);
49  DeferredFunctionInfo.clear();
50  MDKindMap.clear();
51}
52
53//===----------------------------------------------------------------------===//
54//  Helper functions to implement forward reference resolution, etc.
55//===----------------------------------------------------------------------===//
56
57/// ConvertToString - Convert a string from a record into an std::string, return
58/// true on failure.
59template<typename StrTy>
60static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
61                            StrTy &Result) {
62  if (Idx > Record.size())
63    return true;
64
65  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
66    Result += (char)Record[i];
67  return false;
68}
69
70static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
71  switch (Val) {
72  default: // Map unknown/new linkages to external
73  case 0:  return GlobalValue::ExternalLinkage;
74  case 1:  return GlobalValue::WeakAnyLinkage;
75  case 2:  return GlobalValue::AppendingLinkage;
76  case 3:  return GlobalValue::InternalLinkage;
77  case 4:  return GlobalValue::LinkOnceAnyLinkage;
78  case 5:  return GlobalValue::DLLImportLinkage;
79  case 6:  return GlobalValue::DLLExportLinkage;
80  case 7:  return GlobalValue::ExternalWeakLinkage;
81  case 8:  return GlobalValue::CommonLinkage;
82  case 9:  return GlobalValue::PrivateLinkage;
83  case 10: return GlobalValue::WeakODRLinkage;
84  case 11: return GlobalValue::LinkOnceODRLinkage;
85  case 12: return GlobalValue::AvailableExternallyLinkage;
86  case 13: return GlobalValue::LinkerPrivateLinkage;
87  case 14: return GlobalValue::LinkerPrivateWeakLinkage;
88  case 15: return GlobalValue::LinkerPrivateWeakDefAutoLinkage;
89  }
90}
91
92static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
93  switch (Val) {
94  default: // Map unknown visibilities to default.
95  case 0: return GlobalValue::DefaultVisibility;
96  case 1: return GlobalValue::HiddenVisibility;
97  case 2: return GlobalValue::ProtectedVisibility;
98  }
99}
100
101static int GetDecodedCastOpcode(unsigned Val) {
102  switch (Val) {
103  default: return -1;
104  case bitc::CAST_TRUNC   : return Instruction::Trunc;
105  case bitc::CAST_ZEXT    : return Instruction::ZExt;
106  case bitc::CAST_SEXT    : return Instruction::SExt;
107  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
108  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
109  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
110  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
111  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
112  case bitc::CAST_FPEXT   : return Instruction::FPExt;
113  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
114  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
115  case bitc::CAST_BITCAST : return Instruction::BitCast;
116  }
117}
118static int GetDecodedBinaryOpcode(unsigned Val, Type *Ty) {
119  switch (Val) {
120  default: return -1;
121  case bitc::BINOP_ADD:
122    return Ty->isFPOrFPVectorTy() ? Instruction::FAdd : Instruction::Add;
123  case bitc::BINOP_SUB:
124    return Ty->isFPOrFPVectorTy() ? Instruction::FSub : Instruction::Sub;
125  case bitc::BINOP_MUL:
126    return Ty->isFPOrFPVectorTy() ? Instruction::FMul : Instruction::Mul;
127  case bitc::BINOP_UDIV: return Instruction::UDiv;
128  case bitc::BINOP_SDIV:
129    return Ty->isFPOrFPVectorTy() ? Instruction::FDiv : Instruction::SDiv;
130  case bitc::BINOP_UREM: return Instruction::URem;
131  case bitc::BINOP_SREM:
132    return Ty->isFPOrFPVectorTy() ? Instruction::FRem : Instruction::SRem;
133  case bitc::BINOP_SHL:  return Instruction::Shl;
134  case bitc::BINOP_LSHR: return Instruction::LShr;
135  case bitc::BINOP_ASHR: return Instruction::AShr;
136  case bitc::BINOP_AND:  return Instruction::And;
137  case bitc::BINOP_OR:   return Instruction::Or;
138  case bitc::BINOP_XOR:  return Instruction::Xor;
139  }
140}
141
142static AtomicRMWInst::BinOp GetDecodedRMWOperation(unsigned Val) {
143  switch (Val) {
144  default: return AtomicRMWInst::BAD_BINOP;
145  case bitc::RMW_XCHG: return AtomicRMWInst::Xchg;
146  case bitc::RMW_ADD: return AtomicRMWInst::Add;
147  case bitc::RMW_SUB: return AtomicRMWInst::Sub;
148  case bitc::RMW_AND: return AtomicRMWInst::And;
149  case bitc::RMW_NAND: return AtomicRMWInst::Nand;
150  case bitc::RMW_OR: return AtomicRMWInst::Or;
151  case bitc::RMW_XOR: return AtomicRMWInst::Xor;
152  case bitc::RMW_MAX: return AtomicRMWInst::Max;
153  case bitc::RMW_MIN: return AtomicRMWInst::Min;
154  case bitc::RMW_UMAX: return AtomicRMWInst::UMax;
155  case bitc::RMW_UMIN: return AtomicRMWInst::UMin;
156  }
157}
158
159static AtomicOrdering GetDecodedOrdering(unsigned Val) {
160  switch (Val) {
161  case bitc::ORDERING_NOTATOMIC: return NotAtomic;
162  case bitc::ORDERING_UNORDERED: return Unordered;
163  case bitc::ORDERING_MONOTONIC: return Monotonic;
164  case bitc::ORDERING_ACQUIRE: return Acquire;
165  case bitc::ORDERING_RELEASE: return Release;
166  case bitc::ORDERING_ACQREL: return AcquireRelease;
167  default: // Map unknown orderings to sequentially-consistent.
168  case bitc::ORDERING_SEQCST: return SequentiallyConsistent;
169  }
170}
171
172static SynchronizationScope GetDecodedSynchScope(unsigned Val) {
173  switch (Val) {
174  case bitc::SYNCHSCOPE_SINGLETHREAD: return SingleThread;
175  default: // Map unknown scopes to cross-thread.
176  case bitc::SYNCHSCOPE_CROSSTHREAD: return CrossThread;
177  }
178}
179
180namespace llvm {
181namespace {
182  /// @brief A class for maintaining the slot number definition
183  /// as a placeholder for the actual definition for forward constants defs.
184  class ConstantPlaceHolder : public ConstantExpr {
185    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
186  public:
187    // allocate space for exactly one operand
188    void *operator new(size_t s) {
189      return User::operator new(s, 1);
190    }
191    explicit ConstantPlaceHolder(Type *Ty, LLVMContext& Context)
192      : ConstantExpr(Ty, Instruction::UserOp1, &Op<0>(), 1) {
193      Op<0>() = UndefValue::get(Type::getInt32Ty(Context));
194    }
195
196    /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
197    //static inline bool classof(const ConstantPlaceHolder *) { return true; }
198    static bool classof(const Value *V) {
199      return isa<ConstantExpr>(V) &&
200             cast<ConstantExpr>(V)->getOpcode() == Instruction::UserOp1;
201    }
202
203
204    /// Provide fast operand accessors
205    //DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
206  };
207}
208
209// FIXME: can we inherit this from ConstantExpr?
210template <>
211struct OperandTraits<ConstantPlaceHolder> :
212  public FixedNumOperandTraits<ConstantPlaceHolder, 1> {
213};
214}
215
216
217void BitcodeReaderValueList::AssignValue(Value *V, unsigned Idx) {
218  if (Idx == size()) {
219    push_back(V);
220    return;
221  }
222
223  if (Idx >= size())
224    resize(Idx+1);
225
226  WeakVH &OldV = ValuePtrs[Idx];
227  if (OldV == 0) {
228    OldV = V;
229    return;
230  }
231
232  // Handle constants and non-constants (e.g. instrs) differently for
233  // efficiency.
234  if (Constant *PHC = dyn_cast<Constant>(&*OldV)) {
235    ResolveConstants.push_back(std::make_pair(PHC, Idx));
236    OldV = V;
237  } else {
238    // If there was a forward reference to this value, replace it.
239    Value *PrevVal = OldV;
240    OldV->replaceAllUsesWith(V);
241    delete PrevVal;
242  }
243}
244
245
246Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
247                                                    Type *Ty) {
248  if (Idx >= size())
249    resize(Idx + 1);
250
251  if (Value *V = ValuePtrs[Idx]) {
252    assert(Ty == V->getType() && "Type mismatch in constant table!");
253    return cast<Constant>(V);
254  }
255
256  // Create and return a placeholder, which will later be RAUW'd.
257  Constant *C = new ConstantPlaceHolder(Ty, Context);
258  ValuePtrs[Idx] = C;
259  return C;
260}
261
262Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, Type *Ty) {
263  if (Idx >= size())
264    resize(Idx + 1);
265
266  if (Value *V = ValuePtrs[Idx]) {
267    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
268    return V;
269  }
270
271  // No type specified, must be invalid reference.
272  if (Ty == 0) return 0;
273
274  // Create and return a placeholder, which will later be RAUW'd.
275  Value *V = new Argument(Ty);
276  ValuePtrs[Idx] = V;
277  return V;
278}
279
280/// ResolveConstantForwardRefs - Once all constants are read, this method bulk
281/// resolves any forward references.  The idea behind this is that we sometimes
282/// get constants (such as large arrays) which reference *many* forward ref
283/// constants.  Replacing each of these causes a lot of thrashing when
284/// building/reuniquing the constant.  Instead of doing this, we look at all the
285/// uses and rewrite all the place holders at once for any constant that uses
286/// a placeholder.
287void BitcodeReaderValueList::ResolveConstantForwardRefs() {
288  // Sort the values by-pointer so that they are efficient to look up with a
289  // binary search.
290  std::sort(ResolveConstants.begin(), ResolveConstants.end());
291
292  SmallVector<Constant*, 64> NewOps;
293
294  while (!ResolveConstants.empty()) {
295    Value *RealVal = operator[](ResolveConstants.back().second);
296    Constant *Placeholder = ResolveConstants.back().first;
297    ResolveConstants.pop_back();
298
299    // Loop over all users of the placeholder, updating them to reference the
300    // new value.  If they reference more than one placeholder, update them all
301    // at once.
302    while (!Placeholder->use_empty()) {
303      Value::use_iterator UI = Placeholder->use_begin();
304      User *U = *UI;
305
306      // If the using object isn't uniqued, just update the operands.  This
307      // handles instructions and initializers for global variables.
308      if (!isa<Constant>(U) || isa<GlobalValue>(U)) {
309        UI.getUse().set(RealVal);
310        continue;
311      }
312
313      // Otherwise, we have a constant that uses the placeholder.  Replace that
314      // constant with a new constant that has *all* placeholder uses updated.
315      Constant *UserC = cast<Constant>(U);
316      for (User::op_iterator I = UserC->op_begin(), E = UserC->op_end();
317           I != E; ++I) {
318        Value *NewOp;
319        if (!isa<ConstantPlaceHolder>(*I)) {
320          // Not a placeholder reference.
321          NewOp = *I;
322        } else if (*I == Placeholder) {
323          // Common case is that it just references this one placeholder.
324          NewOp = RealVal;
325        } else {
326          // Otherwise, look up the placeholder in ResolveConstants.
327          ResolveConstantsTy::iterator It =
328            std::lower_bound(ResolveConstants.begin(), ResolveConstants.end(),
329                             std::pair<Constant*, unsigned>(cast<Constant>(*I),
330                                                            0));
331          assert(It != ResolveConstants.end() && It->first == *I);
332          NewOp = operator[](It->second);
333        }
334
335        NewOps.push_back(cast<Constant>(NewOp));
336      }
337
338      // Make the new constant.
339      Constant *NewC;
340      if (ConstantArray *UserCA = dyn_cast<ConstantArray>(UserC)) {
341        NewC = ConstantArray::get(UserCA->getType(), NewOps);
342      } else if (ConstantStruct *UserCS = dyn_cast<ConstantStruct>(UserC)) {
343        NewC = ConstantStruct::get(UserCS->getType(), NewOps);
344      } else if (isa<ConstantVector>(UserC)) {
345        NewC = ConstantVector::get(NewOps);
346      } else {
347        assert(isa<ConstantExpr>(UserC) && "Must be a ConstantExpr.");
348        NewC = cast<ConstantExpr>(UserC)->getWithOperands(NewOps);
349      }
350
351      UserC->replaceAllUsesWith(NewC);
352      UserC->destroyConstant();
353      NewOps.clear();
354    }
355
356    // Update all ValueHandles, they should be the only users at this point.
357    Placeholder->replaceAllUsesWith(RealVal);
358    delete Placeholder;
359  }
360}
361
362void BitcodeReaderMDValueList::AssignValue(Value *V, unsigned Idx) {
363  if (Idx == size()) {
364    push_back(V);
365    return;
366  }
367
368  if (Idx >= size())
369    resize(Idx+1);
370
371  WeakVH &OldV = MDValuePtrs[Idx];
372  if (OldV == 0) {
373    OldV = V;
374    return;
375  }
376
377  // If there was a forward reference to this value, replace it.
378  MDNode *PrevVal = cast<MDNode>(OldV);
379  OldV->replaceAllUsesWith(V);
380  MDNode::deleteTemporary(PrevVal);
381  // Deleting PrevVal sets Idx value in MDValuePtrs to null. Set new
382  // value for Idx.
383  MDValuePtrs[Idx] = V;
384}
385
386Value *BitcodeReaderMDValueList::getValueFwdRef(unsigned Idx) {
387  if (Idx >= size())
388    resize(Idx + 1);
389
390  if (Value *V = MDValuePtrs[Idx]) {
391    assert(V->getType()->isMetadataTy() && "Type mismatch in value table!");
392    return V;
393  }
394
395  // Create and return a placeholder, which will later be RAUW'd.
396  Value *V = MDNode::getTemporary(Context, ArrayRef<Value*>());
397  MDValuePtrs[Idx] = V;
398  return V;
399}
400
401Type *BitcodeReader::getTypeByID(unsigned ID) {
402  // The type table size is always specified correctly.
403  if (ID >= TypeList.size())
404    return 0;
405
406  if (Type *Ty = TypeList[ID])
407    return Ty;
408
409  // If we have a forward reference, the only possible case is when it is to a
410  // named struct.  Just create a placeholder for now.
411  return TypeList[ID] = StructType::create(Context);
412}
413
414
415//===----------------------------------------------------------------------===//
416//  Functions for parsing blocks from the bitcode file
417//===----------------------------------------------------------------------===//
418
419bool BitcodeReader::ParseAttributeBlock() {
420  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
421    return Error("Malformed block record");
422
423  if (!MAttributes.empty())
424    return Error("Multiple PARAMATTR blocks found!");
425
426  SmallVector<uint64_t, 64> Record;
427
428  SmallVector<AttributeWithIndex, 8> Attrs;
429
430  // Read all the records.
431  while (1) {
432    unsigned Code = Stream.ReadCode();
433    if (Code == bitc::END_BLOCK) {
434      if (Stream.ReadBlockEnd())
435        return Error("Error at end of PARAMATTR block");
436      return false;
437    }
438
439    if (Code == bitc::ENTER_SUBBLOCK) {
440      // No known subblocks, always skip them.
441      Stream.ReadSubBlockID();
442      if (Stream.SkipBlock())
443        return Error("Malformed block record");
444      continue;
445    }
446
447    if (Code == bitc::DEFINE_ABBREV) {
448      Stream.ReadAbbrevRecord();
449      continue;
450    }
451
452    // Read a record.
453    Record.clear();
454    switch (Stream.ReadRecord(Code, Record)) {
455    default:  // Default behavior: ignore.
456      break;
457    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
458      if (Record.size() & 1)
459        return Error("Invalid ENTRY record");
460
461      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
462        // FIXME: remove in LLVM 3.0
463        // The alignment is stored as a 16-bit raw value from bits 31--16.
464        // We shift the bits above 31 down by 11 bits.
465
466        unsigned Alignment = (Record[i+1] & (0xffffull << 16)) >> 16;
467        if (Alignment && !isPowerOf2_32(Alignment))
468          return Error("Alignment is not a power of two.");
469
470        Attributes ReconstitutedAttr(Record[i+1] & 0xffff);
471        if (Alignment)
472          ReconstitutedAttr |= Attribute::constructAlignmentFromInt(Alignment);
473        ReconstitutedAttr |=
474            Attributes((Record[i+1] & (0xffffull << 32)) >> 11);
475
476        Record[i+1] = ReconstitutedAttr.Raw();
477      }
478
479      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
480        if (Attributes(Record[i+1]) != Attribute::None)
481          Attrs.push_back(AttributeWithIndex::get(Record[i],
482                                                  Attributes(Record[i+1])));
483      }
484
485      MAttributes.push_back(AttrListPtr::get(Attrs.begin(), Attrs.end()));
486      Attrs.clear();
487      break;
488    }
489    }
490  }
491}
492
493bool BitcodeReader::ParseTypeTable() {
494  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID_NEW))
495    return Error("Malformed block record");
496
497  return ParseTypeTableBody();
498}
499
500bool BitcodeReader::ParseTypeTableBody() {
501  if (!TypeList.empty())
502    return Error("Multiple TYPE_BLOCKs found!");
503
504  SmallVector<uint64_t, 64> Record;
505  unsigned NumRecords = 0;
506
507  SmallString<64> TypeName;
508
509  // Read all the records for this type table.
510  while (1) {
511    unsigned Code = Stream.ReadCode();
512    if (Code == bitc::END_BLOCK) {
513      if (NumRecords != TypeList.size())
514        return Error("Invalid type forward reference in TYPE_BLOCK");
515      if (Stream.ReadBlockEnd())
516        return Error("Error at end of type table block");
517      return false;
518    }
519
520    if (Code == bitc::ENTER_SUBBLOCK) {
521      // No known subblocks, always skip them.
522      Stream.ReadSubBlockID();
523      if (Stream.SkipBlock())
524        return Error("Malformed block record");
525      continue;
526    }
527
528    if (Code == bitc::DEFINE_ABBREV) {
529      Stream.ReadAbbrevRecord();
530      continue;
531    }
532
533    // Read a record.
534    Record.clear();
535    Type *ResultTy = 0;
536    switch (Stream.ReadRecord(Code, Record)) {
537    default: return Error("unknown type in type table");
538    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
539      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
540      // type list.  This allows us to reserve space.
541      if (Record.size() < 1)
542        return Error("Invalid TYPE_CODE_NUMENTRY record");
543      TypeList.resize(Record[0]);
544      continue;
545    case bitc::TYPE_CODE_VOID:      // VOID
546      ResultTy = Type::getVoidTy(Context);
547      break;
548    case bitc::TYPE_CODE_HALF:     // HALF
549      ResultTy = Type::getHalfTy(Context);
550      break;
551    case bitc::TYPE_CODE_FLOAT:     // FLOAT
552      ResultTy = Type::getFloatTy(Context);
553      break;
554    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
555      ResultTy = Type::getDoubleTy(Context);
556      break;
557    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
558      ResultTy = Type::getX86_FP80Ty(Context);
559      break;
560    case bitc::TYPE_CODE_FP128:     // FP128
561      ResultTy = Type::getFP128Ty(Context);
562      break;
563    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
564      ResultTy = Type::getPPC_FP128Ty(Context);
565      break;
566    case bitc::TYPE_CODE_LABEL:     // LABEL
567      ResultTy = Type::getLabelTy(Context);
568      break;
569    case bitc::TYPE_CODE_METADATA:  // METADATA
570      ResultTy = Type::getMetadataTy(Context);
571      break;
572    case bitc::TYPE_CODE_X86_MMX:   // X86_MMX
573      ResultTy = Type::getX86_MMXTy(Context);
574      break;
575    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
576      if (Record.size() < 1)
577        return Error("Invalid Integer type record");
578
579      ResultTy = IntegerType::get(Context, Record[0]);
580      break;
581    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
582                                    //          [pointee type, address space]
583      if (Record.size() < 1)
584        return Error("Invalid POINTER type record");
585      unsigned AddressSpace = 0;
586      if (Record.size() == 2)
587        AddressSpace = Record[1];
588      ResultTy = getTypeByID(Record[0]);
589      if (ResultTy == 0) return Error("invalid element type in pointer type");
590      ResultTy = PointerType::get(ResultTy, AddressSpace);
591      break;
592    }
593    case bitc::TYPE_CODE_FUNCTION: {
594      // FUNCTION: [vararg, retty, paramty x N]
595      if (Record.size() < 2)
596        return Error("Invalid FUNCTION type record");
597      SmallVector<Type*, 8> ArgTys;
598      for (unsigned i = 2, e = Record.size(); i != e; ++i) {
599        if (Type *T = getTypeByID(Record[i]))
600          ArgTys.push_back(T);
601        else
602          break;
603      }
604
605      ResultTy = getTypeByID(Record[1]);
606      if (ResultTy == 0 || ArgTys.size() < Record.size()-2)
607        return Error("invalid type in function type");
608
609      ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
610      break;
611    }
612    case bitc::TYPE_CODE_STRUCT_ANON: {  // STRUCT: [ispacked, eltty x N]
613      if (Record.size() < 1)
614        return Error("Invalid STRUCT type record");
615      SmallVector<Type*, 8> EltTys;
616      for (unsigned i = 1, e = Record.size(); i != e; ++i) {
617        if (Type *T = getTypeByID(Record[i]))
618          EltTys.push_back(T);
619        else
620          break;
621      }
622      if (EltTys.size() != Record.size()-1)
623        return Error("invalid type in struct type");
624      ResultTy = StructType::get(Context, EltTys, Record[0]);
625      break;
626    }
627    case bitc::TYPE_CODE_STRUCT_NAME:   // STRUCT_NAME: [strchr x N]
628      if (ConvertToString(Record, 0, TypeName))
629        return Error("Invalid STRUCT_NAME record");
630      continue;
631
632    case bitc::TYPE_CODE_STRUCT_NAMED: { // STRUCT: [ispacked, eltty x N]
633      if (Record.size() < 1)
634        return Error("Invalid STRUCT type record");
635
636      if (NumRecords >= TypeList.size())
637        return Error("invalid TYPE table");
638
639      // Check to see if this was forward referenced, if so fill in the temp.
640      StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
641      if (Res) {
642        Res->setName(TypeName);
643        TypeList[NumRecords] = 0;
644      } else  // Otherwise, create a new struct.
645        Res = StructType::create(Context, TypeName);
646      TypeName.clear();
647
648      SmallVector<Type*, 8> EltTys;
649      for (unsigned i = 1, e = Record.size(); i != e; ++i) {
650        if (Type *T = getTypeByID(Record[i]))
651          EltTys.push_back(T);
652        else
653          break;
654      }
655      if (EltTys.size() != Record.size()-1)
656        return Error("invalid STRUCT type record");
657      Res->setBody(EltTys, Record[0]);
658      ResultTy = Res;
659      break;
660    }
661    case bitc::TYPE_CODE_OPAQUE: {       // OPAQUE: []
662      if (Record.size() != 1)
663        return Error("Invalid OPAQUE type record");
664
665      if (NumRecords >= TypeList.size())
666        return Error("invalid TYPE table");
667
668      // Check to see if this was forward referenced, if so fill in the temp.
669      StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
670      if (Res) {
671        Res->setName(TypeName);
672        TypeList[NumRecords] = 0;
673      } else  // Otherwise, create a new struct with no body.
674        Res = StructType::create(Context, TypeName);
675      TypeName.clear();
676      ResultTy = Res;
677      break;
678    }
679    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
680      if (Record.size() < 2)
681        return Error("Invalid ARRAY type record");
682      if ((ResultTy = getTypeByID(Record[1])))
683        ResultTy = ArrayType::get(ResultTy, Record[0]);
684      else
685        return Error("Invalid ARRAY type element");
686      break;
687    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
688      if (Record.size() < 2)
689        return Error("Invalid VECTOR type record");
690      if ((ResultTy = getTypeByID(Record[1])))
691        ResultTy = VectorType::get(ResultTy, Record[0]);
692      else
693        return Error("Invalid ARRAY type element");
694      break;
695    }
696
697    if (NumRecords >= TypeList.size())
698      return Error("invalid TYPE table");
699    assert(ResultTy && "Didn't read a type?");
700    assert(TypeList[NumRecords] == 0 && "Already read type?");
701    TypeList[NumRecords++] = ResultTy;
702  }
703}
704
705bool BitcodeReader::ParseValueSymbolTable() {
706  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
707    return Error("Malformed block record");
708
709  SmallVector<uint64_t, 64> Record;
710
711  // Read all the records for this value table.
712  SmallString<128> ValueName;
713  while (1) {
714    unsigned Code = Stream.ReadCode();
715    if (Code == bitc::END_BLOCK) {
716      if (Stream.ReadBlockEnd())
717        return Error("Error at end of value symbol table block");
718      return false;
719    }
720    if (Code == bitc::ENTER_SUBBLOCK) {
721      // No known subblocks, always skip them.
722      Stream.ReadSubBlockID();
723      if (Stream.SkipBlock())
724        return Error("Malformed block record");
725      continue;
726    }
727
728    if (Code == bitc::DEFINE_ABBREV) {
729      Stream.ReadAbbrevRecord();
730      continue;
731    }
732
733    // Read a record.
734    Record.clear();
735    switch (Stream.ReadRecord(Code, Record)) {
736    default:  // Default behavior: unknown type.
737      break;
738    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
739      if (ConvertToString(Record, 1, ValueName))
740        return Error("Invalid VST_ENTRY record");
741      unsigned ValueID = Record[0];
742      if (ValueID >= ValueList.size())
743        return Error("Invalid Value ID in VST_ENTRY record");
744      Value *V = ValueList[ValueID];
745
746      V->setName(StringRef(ValueName.data(), ValueName.size()));
747      ValueName.clear();
748      break;
749    }
750    case bitc::VST_CODE_BBENTRY: {
751      if (ConvertToString(Record, 1, ValueName))
752        return Error("Invalid VST_BBENTRY record");
753      BasicBlock *BB = getBasicBlock(Record[0]);
754      if (BB == 0)
755        return Error("Invalid BB ID in VST_BBENTRY record");
756
757      BB->setName(StringRef(ValueName.data(), ValueName.size()));
758      ValueName.clear();
759      break;
760    }
761    }
762  }
763}
764
765bool BitcodeReader::ParseMetadata() {
766  unsigned NextMDValueNo = MDValueList.size();
767
768  if (Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
769    return Error("Malformed block record");
770
771  SmallVector<uint64_t, 64> Record;
772
773  // Read all the records.
774  while (1) {
775    unsigned Code = Stream.ReadCode();
776    if (Code == bitc::END_BLOCK) {
777      if (Stream.ReadBlockEnd())
778        return Error("Error at end of PARAMATTR block");
779      return false;
780    }
781
782    if (Code == bitc::ENTER_SUBBLOCK) {
783      // No known subblocks, always skip them.
784      Stream.ReadSubBlockID();
785      if (Stream.SkipBlock())
786        return Error("Malformed block record");
787      continue;
788    }
789
790    if (Code == bitc::DEFINE_ABBREV) {
791      Stream.ReadAbbrevRecord();
792      continue;
793    }
794
795    bool IsFunctionLocal = false;
796    // Read a record.
797    Record.clear();
798    Code = Stream.ReadRecord(Code, Record);
799    switch (Code) {
800    default:  // Default behavior: ignore.
801      break;
802    case bitc::METADATA_NAME: {
803      // Read named of the named metadata.
804      unsigned NameLength = Record.size();
805      SmallString<8> Name;
806      Name.resize(NameLength);
807      for (unsigned i = 0; i != NameLength; ++i)
808        Name[i] = Record[i];
809      Record.clear();
810      Code = Stream.ReadCode();
811
812      // METADATA_NAME is always followed by METADATA_NAMED_NODE.
813      unsigned NextBitCode = Stream.ReadRecord(Code, Record);
814      assert(NextBitCode == bitc::METADATA_NAMED_NODE); (void)NextBitCode;
815
816      // Read named metadata elements.
817      unsigned Size = Record.size();
818      NamedMDNode *NMD = TheModule->getOrInsertNamedMetadata(Name);
819      for (unsigned i = 0; i != Size; ++i) {
820        MDNode *MD = dyn_cast<MDNode>(MDValueList.getValueFwdRef(Record[i]));
821        if (MD == 0)
822          return Error("Malformed metadata record");
823        NMD->addOperand(MD);
824      }
825      break;
826    }
827    case bitc::METADATA_FN_NODE:
828      IsFunctionLocal = true;
829      // fall-through
830    case bitc::METADATA_NODE: {
831      if (Record.size() % 2 == 1)
832        return Error("Invalid METADATA_NODE record");
833
834      unsigned Size = Record.size();
835      SmallVector<Value*, 8> Elts;
836      for (unsigned i = 0; i != Size; i += 2) {
837        Type *Ty = getTypeByID(Record[i]);
838        if (!Ty) return Error("Invalid METADATA_NODE record");
839        if (Ty->isMetadataTy())
840          Elts.push_back(MDValueList.getValueFwdRef(Record[i+1]));
841        else if (!Ty->isVoidTy())
842          Elts.push_back(ValueList.getValueFwdRef(Record[i+1], Ty));
843        else
844          Elts.push_back(NULL);
845      }
846      Value *V = MDNode::getWhenValsUnresolved(Context, Elts, IsFunctionLocal);
847      IsFunctionLocal = false;
848      MDValueList.AssignValue(V, NextMDValueNo++);
849      break;
850    }
851    case bitc::METADATA_STRING: {
852      unsigned MDStringLength = Record.size();
853      SmallString<8> String;
854      String.resize(MDStringLength);
855      for (unsigned i = 0; i != MDStringLength; ++i)
856        String[i] = Record[i];
857      Value *V = MDString::get(Context,
858                               StringRef(String.data(), String.size()));
859      MDValueList.AssignValue(V, NextMDValueNo++);
860      break;
861    }
862    case bitc::METADATA_KIND: {
863      unsigned RecordLength = Record.size();
864      if (Record.empty() || RecordLength < 2)
865        return Error("Invalid METADATA_KIND record");
866      SmallString<8> Name;
867      Name.resize(RecordLength-1);
868      unsigned Kind = Record[0];
869      for (unsigned i = 1; i != RecordLength; ++i)
870        Name[i-1] = Record[i];
871
872      unsigned NewKind = TheModule->getMDKindID(Name.str());
873      if (!MDKindMap.insert(std::make_pair(Kind, NewKind)).second)
874        return Error("Conflicting METADATA_KIND records");
875      break;
876    }
877    }
878  }
879}
880
881/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
882/// the LSB for dense VBR encoding.
883static uint64_t DecodeSignRotatedValue(uint64_t V) {
884  if ((V & 1) == 0)
885    return V >> 1;
886  if (V != 1)
887    return -(V >> 1);
888  // There is no such thing as -0 with integers.  "-0" really means MININT.
889  return 1ULL << 63;
890}
891
892/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
893/// values and aliases that we can.
894bool BitcodeReader::ResolveGlobalAndAliasInits() {
895  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
896  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
897
898  GlobalInitWorklist.swap(GlobalInits);
899  AliasInitWorklist.swap(AliasInits);
900
901  while (!GlobalInitWorklist.empty()) {
902    unsigned ValID = GlobalInitWorklist.back().second;
903    if (ValID >= ValueList.size()) {
904      // Not ready to resolve this yet, it requires something later in the file.
905      GlobalInits.push_back(GlobalInitWorklist.back());
906    } else {
907      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
908        GlobalInitWorklist.back().first->setInitializer(C);
909      else
910        return Error("Global variable initializer is not a constant!");
911    }
912    GlobalInitWorklist.pop_back();
913  }
914
915  while (!AliasInitWorklist.empty()) {
916    unsigned ValID = AliasInitWorklist.back().second;
917    if (ValID >= ValueList.size()) {
918      AliasInits.push_back(AliasInitWorklist.back());
919    } else {
920      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
921        AliasInitWorklist.back().first->setAliasee(C);
922      else
923        return Error("Alias initializer is not a constant!");
924    }
925    AliasInitWorklist.pop_back();
926  }
927  return false;
928}
929
930bool BitcodeReader::ParseConstants() {
931  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
932    return Error("Malformed block record");
933
934  SmallVector<uint64_t, 64> Record;
935
936  // Read all the records for this value table.
937  Type *CurTy = Type::getInt32Ty(Context);
938  unsigned NextCstNo = ValueList.size();
939  while (1) {
940    unsigned Code = Stream.ReadCode();
941    if (Code == bitc::END_BLOCK)
942      break;
943
944    if (Code == bitc::ENTER_SUBBLOCK) {
945      // No known subblocks, always skip them.
946      Stream.ReadSubBlockID();
947      if (Stream.SkipBlock())
948        return Error("Malformed block record");
949      continue;
950    }
951
952    if (Code == bitc::DEFINE_ABBREV) {
953      Stream.ReadAbbrevRecord();
954      continue;
955    }
956
957    // Read a record.
958    Record.clear();
959    Value *V = 0;
960    unsigned BitCode = Stream.ReadRecord(Code, Record);
961    switch (BitCode) {
962    default:  // Default behavior: unknown constant
963    case bitc::CST_CODE_UNDEF:     // UNDEF
964      V = UndefValue::get(CurTy);
965      break;
966    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
967      if (Record.empty())
968        return Error("Malformed CST_SETTYPE record");
969      if (Record[0] >= TypeList.size())
970        return Error("Invalid Type ID in CST_SETTYPE record");
971      CurTy = TypeList[Record[0]];
972      continue;  // Skip the ValueList manipulation.
973    case bitc::CST_CODE_NULL:      // NULL
974      V = Constant::getNullValue(CurTy);
975      break;
976    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
977      if (!CurTy->isIntegerTy() || Record.empty())
978        return Error("Invalid CST_INTEGER record");
979      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
980      break;
981    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
982      if (!CurTy->isIntegerTy() || Record.empty())
983        return Error("Invalid WIDE_INTEGER record");
984
985      unsigned NumWords = Record.size();
986      SmallVector<uint64_t, 8> Words;
987      Words.resize(NumWords);
988      for (unsigned i = 0; i != NumWords; ++i)
989        Words[i] = DecodeSignRotatedValue(Record[i]);
990      V = ConstantInt::get(Context,
991                           APInt(cast<IntegerType>(CurTy)->getBitWidth(),
992                                 Words));
993      break;
994    }
995    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
996      if (Record.empty())
997        return Error("Invalid FLOAT record");
998      if (CurTy->isHalfTy())
999        V = ConstantFP::get(Context, APFloat(APInt(16, (uint16_t)Record[0])));
1000      else if (CurTy->isFloatTy())
1001        V = ConstantFP::get(Context, APFloat(APInt(32, (uint32_t)Record[0])));
1002      else if (CurTy->isDoubleTy())
1003        V = ConstantFP::get(Context, APFloat(APInt(64, Record[0])));
1004      else if (CurTy->isX86_FP80Ty()) {
1005        // Bits are not stored the same way as a normal i80 APInt, compensate.
1006        uint64_t Rearrange[2];
1007        Rearrange[0] = (Record[1] & 0xffffLL) | (Record[0] << 16);
1008        Rearrange[1] = Record[0] >> 48;
1009        V = ConstantFP::get(Context, APFloat(APInt(80, Rearrange)));
1010      } else if (CurTy->isFP128Ty())
1011        V = ConstantFP::get(Context, APFloat(APInt(128, Record), true));
1012      else if (CurTy->isPPC_FP128Ty())
1013        V = ConstantFP::get(Context, APFloat(APInt(128, Record)));
1014      else
1015        V = UndefValue::get(CurTy);
1016      break;
1017    }
1018
1019    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
1020      if (Record.empty())
1021        return Error("Invalid CST_AGGREGATE record");
1022
1023      unsigned Size = Record.size();
1024      SmallVector<Constant*, 16> Elts;
1025
1026      if (StructType *STy = dyn_cast<StructType>(CurTy)) {
1027        for (unsigned i = 0; i != Size; ++i)
1028          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
1029                                                     STy->getElementType(i)));
1030        V = ConstantStruct::get(STy, Elts);
1031      } else if (ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
1032        Type *EltTy = ATy->getElementType();
1033        for (unsigned i = 0; i != Size; ++i)
1034          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1035        V = ConstantArray::get(ATy, Elts);
1036      } else if (VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
1037        Type *EltTy = VTy->getElementType();
1038        for (unsigned i = 0; i != Size; ++i)
1039          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1040        V = ConstantVector::get(Elts);
1041      } else {
1042        V = UndefValue::get(CurTy);
1043      }
1044      break;
1045    }
1046    case bitc::CST_CODE_STRING:    // STRING: [values]
1047    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
1048      if (Record.empty())
1049        return Error("Invalid CST_STRING record");
1050
1051      unsigned Size = Record.size();
1052      SmallString<16> Elts;
1053      for (unsigned i = 0; i != Size; ++i)
1054        Elts.push_back(Record[i]);
1055      V = ConstantDataArray::getString(Context, Elts,
1056                                       BitCode == bitc::CST_CODE_CSTRING);
1057      break;
1058    }
1059    case bitc::CST_CODE_DATA: {// DATA: [n x value]
1060      if (Record.empty())
1061        return Error("Invalid CST_DATA record");
1062
1063      Type *EltTy = cast<SequentialType>(CurTy)->getElementType();
1064      unsigned Size = Record.size();
1065
1066      if (EltTy->isIntegerTy(8)) {
1067        SmallVector<uint8_t, 16> Elts(Record.begin(), Record.end());
1068        if (isa<VectorType>(CurTy))
1069          V = ConstantDataVector::get(Context, Elts);
1070        else
1071          V = ConstantDataArray::get(Context, Elts);
1072      } else if (EltTy->isIntegerTy(16)) {
1073        SmallVector<uint16_t, 16> Elts(Record.begin(), Record.end());
1074        if (isa<VectorType>(CurTy))
1075          V = ConstantDataVector::get(Context, Elts);
1076        else
1077          V = ConstantDataArray::get(Context, Elts);
1078      } else if (EltTy->isIntegerTy(32)) {
1079        SmallVector<uint32_t, 16> Elts(Record.begin(), Record.end());
1080        if (isa<VectorType>(CurTy))
1081          V = ConstantDataVector::get(Context, Elts);
1082        else
1083          V = ConstantDataArray::get(Context, Elts);
1084      } else if (EltTy->isIntegerTy(64)) {
1085        SmallVector<uint64_t, 16> Elts(Record.begin(), Record.end());
1086        if (isa<VectorType>(CurTy))
1087          V = ConstantDataVector::get(Context, Elts);
1088        else
1089          V = ConstantDataArray::get(Context, Elts);
1090      } else if (EltTy->isFloatTy()) {
1091        SmallVector<float, 16> Elts;
1092        for (unsigned i = 0; i != Size; ++i) {
1093          union { uint32_t I; float F; };
1094          I = Record[i];
1095          Elts.push_back(F);
1096        }
1097        if (isa<VectorType>(CurTy))
1098          V = ConstantDataVector::get(Context, Elts);
1099        else
1100          V = ConstantDataArray::get(Context, Elts);
1101      } else if (EltTy->isDoubleTy()) {
1102        SmallVector<double, 16> Elts;
1103        for (unsigned i = 0; i != Size; ++i) {
1104          union { uint64_t I; double F; };
1105          I = Record[i];
1106          Elts.push_back(F);
1107        }
1108        if (isa<VectorType>(CurTy))
1109          V = ConstantDataVector::get(Context, Elts);
1110        else
1111          V = ConstantDataArray::get(Context, Elts);
1112      } else {
1113        return Error("Unknown element type in CE_DATA");
1114      }
1115      break;
1116    }
1117
1118    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
1119      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
1120      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
1121      if (Opc < 0) {
1122        V = UndefValue::get(CurTy);  // Unknown binop.
1123      } else {
1124        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
1125        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
1126        unsigned Flags = 0;
1127        if (Record.size() >= 4) {
1128          if (Opc == Instruction::Add ||
1129              Opc == Instruction::Sub ||
1130              Opc == Instruction::Mul ||
1131              Opc == Instruction::Shl) {
1132            if (Record[3] & (1 << bitc::OBO_NO_SIGNED_WRAP))
1133              Flags |= OverflowingBinaryOperator::NoSignedWrap;
1134            if (Record[3] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
1135              Flags |= OverflowingBinaryOperator::NoUnsignedWrap;
1136          } else if (Opc == Instruction::SDiv ||
1137                     Opc == Instruction::UDiv ||
1138                     Opc == Instruction::LShr ||
1139                     Opc == Instruction::AShr) {
1140            if (Record[3] & (1 << bitc::PEO_EXACT))
1141              Flags |= SDivOperator::IsExact;
1142          }
1143        }
1144        V = ConstantExpr::get(Opc, LHS, RHS, Flags);
1145      }
1146      break;
1147    }
1148    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
1149      if (Record.size() < 3) return Error("Invalid CE_CAST record");
1150      int Opc = GetDecodedCastOpcode(Record[0]);
1151      if (Opc < 0) {
1152        V = UndefValue::get(CurTy);  // Unknown cast.
1153      } else {
1154        Type *OpTy = getTypeByID(Record[1]);
1155        if (!OpTy) return Error("Invalid CE_CAST record");
1156        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
1157        V = ConstantExpr::getCast(Opc, Op, CurTy);
1158      }
1159      break;
1160    }
1161    case bitc::CST_CODE_CE_INBOUNDS_GEP:
1162    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
1163      if (Record.size() & 1) return Error("Invalid CE_GEP record");
1164      SmallVector<Constant*, 16> Elts;
1165      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
1166        Type *ElTy = getTypeByID(Record[i]);
1167        if (!ElTy) return Error("Invalid CE_GEP record");
1168        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
1169      }
1170      ArrayRef<Constant *> Indices(Elts.begin() + 1, Elts.end());
1171      V = ConstantExpr::getGetElementPtr(Elts[0], Indices,
1172                                         BitCode ==
1173                                           bitc::CST_CODE_CE_INBOUNDS_GEP);
1174      break;
1175    }
1176    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
1177      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
1178      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
1179                                                              Type::getInt1Ty(Context)),
1180                                  ValueList.getConstantFwdRef(Record[1],CurTy),
1181                                  ValueList.getConstantFwdRef(Record[2],CurTy));
1182      break;
1183    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
1184      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
1185      VectorType *OpTy =
1186        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1187      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
1188      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1189      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
1190      V = ConstantExpr::getExtractElement(Op0, Op1);
1191      break;
1192    }
1193    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
1194      VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1195      if (Record.size() < 3 || OpTy == 0)
1196        return Error("Invalid CE_INSERTELT record");
1197      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1198      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
1199                                                  OpTy->getElementType());
1200      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
1201      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
1202      break;
1203    }
1204    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
1205      VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1206      if (Record.size() < 3 || OpTy == 0)
1207        return Error("Invalid CE_SHUFFLEVEC record");
1208      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1209      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
1210      Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
1211                                                 OpTy->getNumElements());
1212      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
1213      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1214      break;
1215    }
1216    case bitc::CST_CODE_CE_SHUFVEC_EX: { // [opty, opval, opval, opval]
1217      VectorType *RTy = dyn_cast<VectorType>(CurTy);
1218      VectorType *OpTy =
1219        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1220      if (Record.size() < 4 || RTy == 0 || OpTy == 0)
1221        return Error("Invalid CE_SHUFVEC_EX record");
1222      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1223      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1224      Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
1225                                                 RTy->getNumElements());
1226      Constant *Op2 = ValueList.getConstantFwdRef(Record[3], ShufTy);
1227      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1228      break;
1229    }
1230    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
1231      if (Record.size() < 4) return Error("Invalid CE_CMP record");
1232      Type *OpTy = getTypeByID(Record[0]);
1233      if (OpTy == 0) return Error("Invalid CE_CMP record");
1234      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1235      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1236
1237      if (OpTy->isFPOrFPVectorTy())
1238        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
1239      else
1240        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
1241      break;
1242    }
1243    case bitc::CST_CODE_INLINEASM: {
1244      if (Record.size() < 2) return Error("Invalid INLINEASM record");
1245      std::string AsmStr, ConstrStr;
1246      bool HasSideEffects = Record[0] & 1;
1247      bool IsAlignStack = Record[0] >> 1;
1248      unsigned AsmStrSize = Record[1];
1249      if (2+AsmStrSize >= Record.size())
1250        return Error("Invalid INLINEASM record");
1251      unsigned ConstStrSize = Record[2+AsmStrSize];
1252      if (3+AsmStrSize+ConstStrSize > Record.size())
1253        return Error("Invalid INLINEASM record");
1254
1255      for (unsigned i = 0; i != AsmStrSize; ++i)
1256        AsmStr += (char)Record[2+i];
1257      for (unsigned i = 0; i != ConstStrSize; ++i)
1258        ConstrStr += (char)Record[3+AsmStrSize+i];
1259      PointerType *PTy = cast<PointerType>(CurTy);
1260      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
1261                         AsmStr, ConstrStr, HasSideEffects, IsAlignStack);
1262      break;
1263    }
1264    case bitc::CST_CODE_BLOCKADDRESS:{
1265      if (Record.size() < 3) return Error("Invalid CE_BLOCKADDRESS record");
1266      Type *FnTy = getTypeByID(Record[0]);
1267      if (FnTy == 0) return Error("Invalid CE_BLOCKADDRESS record");
1268      Function *Fn =
1269        dyn_cast_or_null<Function>(ValueList.getConstantFwdRef(Record[1],FnTy));
1270      if (Fn == 0) return Error("Invalid CE_BLOCKADDRESS record");
1271
1272      GlobalVariable *FwdRef = new GlobalVariable(*Fn->getParent(),
1273                                                  Type::getInt8Ty(Context),
1274                                            false, GlobalValue::InternalLinkage,
1275                                                  0, "");
1276      BlockAddrFwdRefs[Fn].push_back(std::make_pair(Record[2], FwdRef));
1277      V = FwdRef;
1278      break;
1279    }
1280    }
1281
1282    ValueList.AssignValue(V, NextCstNo);
1283    ++NextCstNo;
1284  }
1285
1286  if (NextCstNo != ValueList.size())
1287    return Error("Invalid constant reference!");
1288
1289  if (Stream.ReadBlockEnd())
1290    return Error("Error at end of constants block");
1291
1292  // Once all the constants have been read, go through and resolve forward
1293  // references.
1294  ValueList.ResolveConstantForwardRefs();
1295  return false;
1296}
1297
1298bool BitcodeReader::ParseUseLists() {
1299  if (Stream.EnterSubBlock(bitc::USELIST_BLOCK_ID))
1300    return Error("Malformed block record");
1301
1302  SmallVector<uint64_t, 64> Record;
1303
1304  // Read all the records.
1305  while (1) {
1306    unsigned Code = Stream.ReadCode();
1307    if (Code == bitc::END_BLOCK) {
1308      if (Stream.ReadBlockEnd())
1309        return Error("Error at end of use-list table block");
1310      return false;
1311    }
1312
1313    if (Code == bitc::ENTER_SUBBLOCK) {
1314      // No known subblocks, always skip them.
1315      Stream.ReadSubBlockID();
1316      if (Stream.SkipBlock())
1317        return Error("Malformed block record");
1318      continue;
1319    }
1320
1321    if (Code == bitc::DEFINE_ABBREV) {
1322      Stream.ReadAbbrevRecord();
1323      continue;
1324    }
1325
1326    // Read a use list record.
1327    Record.clear();
1328    switch (Stream.ReadRecord(Code, Record)) {
1329    default:  // Default behavior: unknown type.
1330      break;
1331    case bitc::USELIST_CODE_ENTRY: { // USELIST_CODE_ENTRY: TBD.
1332      unsigned RecordLength = Record.size();
1333      if (RecordLength < 1)
1334        return Error ("Invalid UseList reader!");
1335      UseListRecords.push_back(Record);
1336      break;
1337    }
1338    }
1339  }
1340}
1341
1342/// RememberAndSkipFunctionBody - When we see the block for a function body,
1343/// remember where it is and then skip it.  This lets us lazily deserialize the
1344/// functions.
1345bool BitcodeReader::RememberAndSkipFunctionBody() {
1346  // Get the function we are talking about.
1347  if (FunctionsWithBodies.empty())
1348    return Error("Insufficient function protos");
1349
1350  Function *Fn = FunctionsWithBodies.back();
1351  FunctionsWithBodies.pop_back();
1352
1353  // Save the current stream state.
1354  uint64_t CurBit = Stream.GetCurrentBitNo();
1355  DeferredFunctionInfo[Fn] = CurBit;
1356
1357  // Skip over the function block for now.
1358  if (Stream.SkipBlock())
1359    return Error("Malformed block record");
1360  return false;
1361}
1362
1363bool BitcodeReader::GlobalCleanup() {
1364  // Patch the initializers for globals and aliases up.
1365  ResolveGlobalAndAliasInits();
1366  if (!GlobalInits.empty() || !AliasInits.empty())
1367    return Error("Malformed global initializer set");
1368
1369  // Look for intrinsic functions which need to be upgraded at some point
1370  for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
1371       FI != FE; ++FI) {
1372    Function *NewFn;
1373    if (UpgradeIntrinsicFunction(FI, NewFn))
1374      UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
1375  }
1376
1377  // Look for global variables which need to be renamed.
1378  for (Module::global_iterator
1379         GI = TheModule->global_begin(), GE = TheModule->global_end();
1380       GI != GE; ++GI)
1381    UpgradeGlobalVariable(GI);
1382  // Force deallocation of memory for these vectors to favor the client that
1383  // want lazy deserialization.
1384  std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
1385  std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
1386  return false;
1387}
1388
1389bool BitcodeReader::ParseModule(bool Resume) {
1390  if (Resume)
1391    Stream.JumpToBit(NextUnreadBit);
1392  else if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
1393    return Error("Malformed block record");
1394
1395  SmallVector<uint64_t, 64> Record;
1396  std::vector<std::string> SectionTable;
1397  std::vector<std::string> GCTable;
1398
1399  // Read all the records for this module.
1400  while (!Stream.AtEndOfStream()) {
1401    unsigned Code = Stream.ReadCode();
1402    if (Code == bitc::END_BLOCK) {
1403      if (Stream.ReadBlockEnd())
1404        return Error("Error at end of module block");
1405
1406      return GlobalCleanup();
1407    }
1408
1409    if (Code == bitc::ENTER_SUBBLOCK) {
1410      switch (Stream.ReadSubBlockID()) {
1411      default:  // Skip unknown content.
1412        if (Stream.SkipBlock())
1413          return Error("Malformed block record");
1414        break;
1415      case bitc::BLOCKINFO_BLOCK_ID:
1416        if (Stream.ReadBlockInfoBlock())
1417          return Error("Malformed BlockInfoBlock");
1418        break;
1419      case bitc::PARAMATTR_BLOCK_ID:
1420        if (ParseAttributeBlock())
1421          return true;
1422        break;
1423      case bitc::TYPE_BLOCK_ID_NEW:
1424        if (ParseTypeTable())
1425          return true;
1426        break;
1427      case bitc::VALUE_SYMTAB_BLOCK_ID:
1428        if (ParseValueSymbolTable())
1429          return true;
1430        SeenValueSymbolTable = true;
1431        break;
1432      case bitc::CONSTANTS_BLOCK_ID:
1433        if (ParseConstants() || ResolveGlobalAndAliasInits())
1434          return true;
1435        break;
1436      case bitc::METADATA_BLOCK_ID:
1437        if (ParseMetadata())
1438          return true;
1439        break;
1440      case bitc::FUNCTION_BLOCK_ID:
1441        // If this is the first function body we've seen, reverse the
1442        // FunctionsWithBodies list.
1443        if (!SeenFirstFunctionBody) {
1444          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
1445          if (GlobalCleanup())
1446            return true;
1447          SeenFirstFunctionBody = true;
1448        }
1449
1450        if (RememberAndSkipFunctionBody())
1451          return true;
1452        // For streaming bitcode, suspend parsing when we reach the function
1453        // bodies. Subsequent materialization calls will resume it when
1454        // necessary. For streaming, the function bodies must be at the end of
1455        // the bitcode. If the bitcode file is old, the symbol table will be
1456        // at the end instead and will not have been seen yet. In this case,
1457        // just finish the parse now.
1458        if (LazyStreamer && SeenValueSymbolTable) {
1459          NextUnreadBit = Stream.GetCurrentBitNo();
1460          return false;
1461        }
1462        break;
1463      case bitc::USELIST_BLOCK_ID:
1464        if (ParseUseLists())
1465          return true;
1466        break;
1467      }
1468      continue;
1469    }
1470
1471    if (Code == bitc::DEFINE_ABBREV) {
1472      Stream.ReadAbbrevRecord();
1473      continue;
1474    }
1475
1476    // Read a record.
1477    switch (Stream.ReadRecord(Code, Record)) {
1478    default: break;  // Default behavior, ignore unknown content.
1479    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
1480      if (Record.size() < 1)
1481        return Error("Malformed MODULE_CODE_VERSION");
1482      // Only version #0 is supported so far.
1483      if (Record[0] != 0)
1484        return Error("Unknown bitstream version!");
1485      break;
1486    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1487      std::string S;
1488      if (ConvertToString(Record, 0, S))
1489        return Error("Invalid MODULE_CODE_TRIPLE record");
1490      TheModule->setTargetTriple(S);
1491      break;
1492    }
1493    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
1494      std::string S;
1495      if (ConvertToString(Record, 0, S))
1496        return Error("Invalid MODULE_CODE_DATALAYOUT record");
1497      TheModule->setDataLayout(S);
1498      break;
1499    }
1500    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
1501      std::string S;
1502      if (ConvertToString(Record, 0, S))
1503        return Error("Invalid MODULE_CODE_ASM record");
1504      TheModule->setModuleInlineAsm(S);
1505      break;
1506    }
1507    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
1508      std::string S;
1509      if (ConvertToString(Record, 0, S))
1510        return Error("Invalid MODULE_CODE_DEPLIB record");
1511      TheModule->addLibrary(S);
1512      break;
1513    }
1514    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
1515      std::string S;
1516      if (ConvertToString(Record, 0, S))
1517        return Error("Invalid MODULE_CODE_SECTIONNAME record");
1518      SectionTable.push_back(S);
1519      break;
1520    }
1521    case bitc::MODULE_CODE_GCNAME: {  // SECTIONNAME: [strchr x N]
1522      std::string S;
1523      if (ConvertToString(Record, 0, S))
1524        return Error("Invalid MODULE_CODE_GCNAME record");
1525      GCTable.push_back(S);
1526      break;
1527    }
1528    // GLOBALVAR: [pointer type, isconst, initid,
1529    //             linkage, alignment, section, visibility, threadlocal,
1530    //             unnamed_addr]
1531    case bitc::MODULE_CODE_GLOBALVAR: {
1532      if (Record.size() < 6)
1533        return Error("Invalid MODULE_CODE_GLOBALVAR record");
1534      Type *Ty = getTypeByID(Record[0]);
1535      if (!Ty) return Error("Invalid MODULE_CODE_GLOBALVAR record");
1536      if (!Ty->isPointerTy())
1537        return Error("Global not a pointer type!");
1538      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
1539      Ty = cast<PointerType>(Ty)->getElementType();
1540
1541      bool isConstant = Record[1];
1542      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1543      unsigned Alignment = (1 << Record[4]) >> 1;
1544      std::string Section;
1545      if (Record[5]) {
1546        if (Record[5]-1 >= SectionTable.size())
1547          return Error("Invalid section ID");
1548        Section = SectionTable[Record[5]-1];
1549      }
1550      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1551      if (Record.size() > 6)
1552        Visibility = GetDecodedVisibility(Record[6]);
1553      bool isThreadLocal = false;
1554      if (Record.size() > 7)
1555        isThreadLocal = Record[7];
1556
1557      bool UnnamedAddr = false;
1558      if (Record.size() > 8)
1559        UnnamedAddr = Record[8];
1560
1561      GlobalVariable *NewGV =
1562        new GlobalVariable(*TheModule, Ty, isConstant, Linkage, 0, "", 0,
1563                           isThreadLocal, AddressSpace);
1564      NewGV->setAlignment(Alignment);
1565      if (!Section.empty())
1566        NewGV->setSection(Section);
1567      NewGV->setVisibility(Visibility);
1568      NewGV->setThreadLocal(isThreadLocal);
1569      NewGV->setUnnamedAddr(UnnamedAddr);
1570
1571      ValueList.push_back(NewGV);
1572
1573      // Remember which value to use for the global initializer.
1574      if (unsigned InitID = Record[2])
1575        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1576      break;
1577    }
1578    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1579    //             alignment, section, visibility, gc, unnamed_addr]
1580    case bitc::MODULE_CODE_FUNCTION: {
1581      if (Record.size() < 8)
1582        return Error("Invalid MODULE_CODE_FUNCTION record");
1583      Type *Ty = getTypeByID(Record[0]);
1584      if (!Ty) return Error("Invalid MODULE_CODE_FUNCTION record");
1585      if (!Ty->isPointerTy())
1586        return Error("Function not a pointer type!");
1587      FunctionType *FTy =
1588        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1589      if (!FTy)
1590        return Error("Function not a pointer to function type!");
1591
1592      Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
1593                                        "", TheModule);
1594
1595      Func->setCallingConv(static_cast<CallingConv::ID>(Record[1]));
1596      bool isProto = Record[2];
1597      Func->setLinkage(GetDecodedLinkage(Record[3]));
1598      Func->setAttributes(getAttributes(Record[4]));
1599
1600      Func->setAlignment((1 << Record[5]) >> 1);
1601      if (Record[6]) {
1602        if (Record[6]-1 >= SectionTable.size())
1603          return Error("Invalid section ID");
1604        Func->setSection(SectionTable[Record[6]-1]);
1605      }
1606      Func->setVisibility(GetDecodedVisibility(Record[7]));
1607      if (Record.size() > 8 && Record[8]) {
1608        if (Record[8]-1 > GCTable.size())
1609          return Error("Invalid GC ID");
1610        Func->setGC(GCTable[Record[8]-1].c_str());
1611      }
1612      bool UnnamedAddr = false;
1613      if (Record.size() > 9)
1614        UnnamedAddr = Record[9];
1615      Func->setUnnamedAddr(UnnamedAddr);
1616      ValueList.push_back(Func);
1617
1618      // If this is a function with a body, remember the prototype we are
1619      // creating now, so that we can match up the body with them later.
1620      if (!isProto) {
1621        FunctionsWithBodies.push_back(Func);
1622        if (LazyStreamer) DeferredFunctionInfo[Func] = 0;
1623      }
1624      break;
1625    }
1626    // ALIAS: [alias type, aliasee val#, linkage]
1627    // ALIAS: [alias type, aliasee val#, linkage, visibility]
1628    case bitc::MODULE_CODE_ALIAS: {
1629      if (Record.size() < 3)
1630        return Error("Invalid MODULE_ALIAS record");
1631      Type *Ty = getTypeByID(Record[0]);
1632      if (!Ty) return Error("Invalid MODULE_ALIAS record");
1633      if (!Ty->isPointerTy())
1634        return Error("Function not a pointer type!");
1635
1636      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1637                                           "", 0, TheModule);
1638      // Old bitcode files didn't have visibility field.
1639      if (Record.size() > 3)
1640        NewGA->setVisibility(GetDecodedVisibility(Record[3]));
1641      ValueList.push_back(NewGA);
1642      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1643      break;
1644    }
1645    /// MODULE_CODE_PURGEVALS: [numvals]
1646    case bitc::MODULE_CODE_PURGEVALS:
1647      // Trim down the value list to the specified size.
1648      if (Record.size() < 1 || Record[0] > ValueList.size())
1649        return Error("Invalid MODULE_PURGEVALS record");
1650      ValueList.shrinkTo(Record[0]);
1651      break;
1652    }
1653    Record.clear();
1654  }
1655
1656  return Error("Premature end of bitstream");
1657}
1658
1659bool BitcodeReader::ParseBitcodeInto(Module *M) {
1660  TheModule = 0;
1661
1662  if (InitStream()) return true;
1663
1664  // Sniff for the signature.
1665  if (Stream.Read(8) != 'B' ||
1666      Stream.Read(8) != 'C' ||
1667      Stream.Read(4) != 0x0 ||
1668      Stream.Read(4) != 0xC ||
1669      Stream.Read(4) != 0xE ||
1670      Stream.Read(4) != 0xD)
1671    return Error("Invalid bitcode signature");
1672
1673  // We expect a number of well-defined blocks, though we don't necessarily
1674  // need to understand them all.
1675  while (!Stream.AtEndOfStream()) {
1676    unsigned Code = Stream.ReadCode();
1677
1678    if (Code != bitc::ENTER_SUBBLOCK) {
1679
1680      // The ranlib in xcode 4 will align archive members by appending newlines
1681      // to the end of them. If this file size is a multiple of 4 but not 8, we
1682      // have to read and ignore these final 4 bytes :-(
1683      if (Stream.GetAbbrevIDWidth() == 2 && Code == 2 &&
1684          Stream.Read(6) == 2 && Stream.Read(24) == 0xa0a0a &&
1685	  Stream.AtEndOfStream())
1686        return false;
1687
1688      return Error("Invalid record at top-level");
1689    }
1690
1691    unsigned BlockID = Stream.ReadSubBlockID();
1692
1693    // We only know the MODULE subblock ID.
1694    switch (BlockID) {
1695    case bitc::BLOCKINFO_BLOCK_ID:
1696      if (Stream.ReadBlockInfoBlock())
1697        return Error("Malformed BlockInfoBlock");
1698      break;
1699    case bitc::MODULE_BLOCK_ID:
1700      // Reject multiple MODULE_BLOCK's in a single bitstream.
1701      if (TheModule)
1702        return Error("Multiple MODULE_BLOCKs in same stream");
1703      TheModule = M;
1704      if (ParseModule(false))
1705        return true;
1706      if (LazyStreamer) return false;
1707      break;
1708    default:
1709      if (Stream.SkipBlock())
1710        return Error("Malformed block record");
1711      break;
1712    }
1713  }
1714
1715  return false;
1716}
1717
1718bool BitcodeReader::ParseModuleTriple(std::string &Triple) {
1719  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
1720    return Error("Malformed block record");
1721
1722  SmallVector<uint64_t, 64> Record;
1723
1724  // Read all the records for this module.
1725  while (!Stream.AtEndOfStream()) {
1726    unsigned Code = Stream.ReadCode();
1727    if (Code == bitc::END_BLOCK) {
1728      if (Stream.ReadBlockEnd())
1729        return Error("Error at end of module block");
1730
1731      return false;
1732    }
1733
1734    if (Code == bitc::ENTER_SUBBLOCK) {
1735      switch (Stream.ReadSubBlockID()) {
1736      default:  // Skip unknown content.
1737        if (Stream.SkipBlock())
1738          return Error("Malformed block record");
1739        break;
1740      }
1741      continue;
1742    }
1743
1744    if (Code == bitc::DEFINE_ABBREV) {
1745      Stream.ReadAbbrevRecord();
1746      continue;
1747    }
1748
1749    // Read a record.
1750    switch (Stream.ReadRecord(Code, Record)) {
1751    default: break;  // Default behavior, ignore unknown content.
1752    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
1753      if (Record.size() < 1)
1754        return Error("Malformed MODULE_CODE_VERSION");
1755      // Only version #0 is supported so far.
1756      if (Record[0] != 0)
1757        return Error("Unknown bitstream version!");
1758      break;
1759    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1760      std::string S;
1761      if (ConvertToString(Record, 0, S))
1762        return Error("Invalid MODULE_CODE_TRIPLE record");
1763      Triple = S;
1764      break;
1765    }
1766    }
1767    Record.clear();
1768  }
1769
1770  return Error("Premature end of bitstream");
1771}
1772
1773bool BitcodeReader::ParseTriple(std::string &Triple) {
1774  if (InitStream()) return true;
1775
1776  // Sniff for the signature.
1777  if (Stream.Read(8) != 'B' ||
1778      Stream.Read(8) != 'C' ||
1779      Stream.Read(4) != 0x0 ||
1780      Stream.Read(4) != 0xC ||
1781      Stream.Read(4) != 0xE ||
1782      Stream.Read(4) != 0xD)
1783    return Error("Invalid bitcode signature");
1784
1785  // We expect a number of well-defined blocks, though we don't necessarily
1786  // need to understand them all.
1787  while (!Stream.AtEndOfStream()) {
1788    unsigned Code = Stream.ReadCode();
1789
1790    if (Code != bitc::ENTER_SUBBLOCK)
1791      return Error("Invalid record at top-level");
1792
1793    unsigned BlockID = Stream.ReadSubBlockID();
1794
1795    // We only know the MODULE subblock ID.
1796    switch (BlockID) {
1797    case bitc::MODULE_BLOCK_ID:
1798      if (ParseModuleTriple(Triple))
1799        return true;
1800      break;
1801    default:
1802      if (Stream.SkipBlock())
1803        return Error("Malformed block record");
1804      break;
1805    }
1806  }
1807
1808  return false;
1809}
1810
1811/// ParseMetadataAttachment - Parse metadata attachments.
1812bool BitcodeReader::ParseMetadataAttachment() {
1813  if (Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
1814    return Error("Malformed block record");
1815
1816  SmallVector<uint64_t, 64> Record;
1817  while(1) {
1818    unsigned Code = Stream.ReadCode();
1819    if (Code == bitc::END_BLOCK) {
1820      if (Stream.ReadBlockEnd())
1821        return Error("Error at end of PARAMATTR block");
1822      break;
1823    }
1824    if (Code == bitc::DEFINE_ABBREV) {
1825      Stream.ReadAbbrevRecord();
1826      continue;
1827    }
1828    // Read a metadata attachment record.
1829    Record.clear();
1830    switch (Stream.ReadRecord(Code, Record)) {
1831    default:  // Default behavior: ignore.
1832      break;
1833    case bitc::METADATA_ATTACHMENT: {
1834      unsigned RecordLength = Record.size();
1835      if (Record.empty() || (RecordLength - 1) % 2 == 1)
1836        return Error ("Invalid METADATA_ATTACHMENT reader!");
1837      Instruction *Inst = InstructionList[Record[0]];
1838      for (unsigned i = 1; i != RecordLength; i = i+2) {
1839        unsigned Kind = Record[i];
1840        DenseMap<unsigned, unsigned>::iterator I =
1841          MDKindMap.find(Kind);
1842        if (I == MDKindMap.end())
1843          return Error("Invalid metadata kind ID");
1844        Value *Node = MDValueList.getValueFwdRef(Record[i+1]);
1845        Inst->setMetadata(I->second, cast<MDNode>(Node));
1846      }
1847      break;
1848    }
1849    }
1850  }
1851  return false;
1852}
1853
1854/// ParseFunctionBody - Lazily parse the specified function body block.
1855bool BitcodeReader::ParseFunctionBody(Function *F) {
1856  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1857    return Error("Malformed block record");
1858
1859  InstructionList.clear();
1860  unsigned ModuleValueListSize = ValueList.size();
1861  unsigned ModuleMDValueListSize = MDValueList.size();
1862
1863  // Add all the function arguments to the value table.
1864  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1865    ValueList.push_back(I);
1866
1867  unsigned NextValueNo = ValueList.size();
1868  BasicBlock *CurBB = 0;
1869  unsigned CurBBNo = 0;
1870
1871  DebugLoc LastLoc;
1872
1873  // Read all the records.
1874  SmallVector<uint64_t, 64> Record;
1875  while (1) {
1876    unsigned Code = Stream.ReadCode();
1877    if (Code == bitc::END_BLOCK) {
1878      if (Stream.ReadBlockEnd())
1879        return Error("Error at end of function block");
1880      break;
1881    }
1882
1883    if (Code == bitc::ENTER_SUBBLOCK) {
1884      switch (Stream.ReadSubBlockID()) {
1885      default:  // Skip unknown content.
1886        if (Stream.SkipBlock())
1887          return Error("Malformed block record");
1888        break;
1889      case bitc::CONSTANTS_BLOCK_ID:
1890        if (ParseConstants()) return true;
1891        NextValueNo = ValueList.size();
1892        break;
1893      case bitc::VALUE_SYMTAB_BLOCK_ID:
1894        if (ParseValueSymbolTable()) return true;
1895        break;
1896      case bitc::METADATA_ATTACHMENT_ID:
1897        if (ParseMetadataAttachment()) return true;
1898        break;
1899      case bitc::METADATA_BLOCK_ID:
1900        if (ParseMetadata()) return true;
1901        break;
1902      }
1903      continue;
1904    }
1905
1906    if (Code == bitc::DEFINE_ABBREV) {
1907      Stream.ReadAbbrevRecord();
1908      continue;
1909    }
1910
1911    // Read a record.
1912    Record.clear();
1913    Instruction *I = 0;
1914    unsigned BitCode = Stream.ReadRecord(Code, Record);
1915    switch (BitCode) {
1916    default: // Default behavior: reject
1917      return Error("Unknown instruction");
1918    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1919      if (Record.size() < 1 || Record[0] == 0)
1920        return Error("Invalid DECLAREBLOCKS record");
1921      // Create all the basic blocks for the function.
1922      FunctionBBs.resize(Record[0]);
1923      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1924        FunctionBBs[i] = BasicBlock::Create(Context, "", F);
1925      CurBB = FunctionBBs[0];
1926      continue;
1927
1928    case bitc::FUNC_CODE_DEBUG_LOC_AGAIN:  // DEBUG_LOC_AGAIN
1929      // This record indicates that the last instruction is at the same
1930      // location as the previous instruction with a location.
1931      I = 0;
1932
1933      // Get the last instruction emitted.
1934      if (CurBB && !CurBB->empty())
1935        I = &CurBB->back();
1936      else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
1937               !FunctionBBs[CurBBNo-1]->empty())
1938        I = &FunctionBBs[CurBBNo-1]->back();
1939
1940      if (I == 0) return Error("Invalid DEBUG_LOC_AGAIN record");
1941      I->setDebugLoc(LastLoc);
1942      I = 0;
1943      continue;
1944
1945    case bitc::FUNC_CODE_DEBUG_LOC: {      // DEBUG_LOC: [line, col, scope, ia]
1946      I = 0;     // Get the last instruction emitted.
1947      if (CurBB && !CurBB->empty())
1948        I = &CurBB->back();
1949      else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
1950               !FunctionBBs[CurBBNo-1]->empty())
1951        I = &FunctionBBs[CurBBNo-1]->back();
1952      if (I == 0 || Record.size() < 4)
1953        return Error("Invalid FUNC_CODE_DEBUG_LOC record");
1954
1955      unsigned Line = Record[0], Col = Record[1];
1956      unsigned ScopeID = Record[2], IAID = Record[3];
1957
1958      MDNode *Scope = 0, *IA = 0;
1959      if (ScopeID) Scope = cast<MDNode>(MDValueList.getValueFwdRef(ScopeID-1));
1960      if (IAID)    IA = cast<MDNode>(MDValueList.getValueFwdRef(IAID-1));
1961      LastLoc = DebugLoc::get(Line, Col, Scope, IA);
1962      I->setDebugLoc(LastLoc);
1963      I = 0;
1964      continue;
1965    }
1966
1967    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1968      unsigned OpNum = 0;
1969      Value *LHS, *RHS;
1970      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1971          getValue(Record, OpNum, LHS->getType(), RHS) ||
1972          OpNum+1 > Record.size())
1973        return Error("Invalid BINOP record");
1974
1975      int Opc = GetDecodedBinaryOpcode(Record[OpNum++], LHS->getType());
1976      if (Opc == -1) return Error("Invalid BINOP record");
1977      I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
1978      InstructionList.push_back(I);
1979      if (OpNum < Record.size()) {
1980        if (Opc == Instruction::Add ||
1981            Opc == Instruction::Sub ||
1982            Opc == Instruction::Mul ||
1983            Opc == Instruction::Shl) {
1984          if (Record[OpNum] & (1 << bitc::OBO_NO_SIGNED_WRAP))
1985            cast<BinaryOperator>(I)->setHasNoSignedWrap(true);
1986          if (Record[OpNum] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
1987            cast<BinaryOperator>(I)->setHasNoUnsignedWrap(true);
1988        } else if (Opc == Instruction::SDiv ||
1989                   Opc == Instruction::UDiv ||
1990                   Opc == Instruction::LShr ||
1991                   Opc == Instruction::AShr) {
1992          if (Record[OpNum] & (1 << bitc::PEO_EXACT))
1993            cast<BinaryOperator>(I)->setIsExact(true);
1994        }
1995      }
1996      break;
1997    }
1998    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
1999      unsigned OpNum = 0;
2000      Value *Op;
2001      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2002          OpNum+2 != Record.size())
2003        return Error("Invalid CAST record");
2004
2005      Type *ResTy = getTypeByID(Record[OpNum]);
2006      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
2007      if (Opc == -1 || ResTy == 0)
2008        return Error("Invalid CAST record");
2009      I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
2010      InstructionList.push_back(I);
2011      break;
2012    }
2013    case bitc::FUNC_CODE_INST_INBOUNDS_GEP:
2014    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
2015      unsigned OpNum = 0;
2016      Value *BasePtr;
2017      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
2018        return Error("Invalid GEP record");
2019
2020      SmallVector<Value*, 16> GEPIdx;
2021      while (OpNum != Record.size()) {
2022        Value *Op;
2023        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2024          return Error("Invalid GEP record");
2025        GEPIdx.push_back(Op);
2026      }
2027
2028      I = GetElementPtrInst::Create(BasePtr, GEPIdx);
2029      InstructionList.push_back(I);
2030      if (BitCode == bitc::FUNC_CODE_INST_INBOUNDS_GEP)
2031        cast<GetElementPtrInst>(I)->setIsInBounds(true);
2032      break;
2033    }
2034
2035    case bitc::FUNC_CODE_INST_EXTRACTVAL: {
2036                                       // EXTRACTVAL: [opty, opval, n x indices]
2037      unsigned OpNum = 0;
2038      Value *Agg;
2039      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2040        return Error("Invalid EXTRACTVAL record");
2041
2042      SmallVector<unsigned, 4> EXTRACTVALIdx;
2043      for (unsigned RecSize = Record.size();
2044           OpNum != RecSize; ++OpNum) {
2045        uint64_t Index = Record[OpNum];
2046        if ((unsigned)Index != Index)
2047          return Error("Invalid EXTRACTVAL index");
2048        EXTRACTVALIdx.push_back((unsigned)Index);
2049      }
2050
2051      I = ExtractValueInst::Create(Agg, EXTRACTVALIdx);
2052      InstructionList.push_back(I);
2053      break;
2054    }
2055
2056    case bitc::FUNC_CODE_INST_INSERTVAL: {
2057                           // INSERTVAL: [opty, opval, opty, opval, n x indices]
2058      unsigned OpNum = 0;
2059      Value *Agg;
2060      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2061        return Error("Invalid INSERTVAL record");
2062      Value *Val;
2063      if (getValueTypePair(Record, OpNum, NextValueNo, Val))
2064        return Error("Invalid INSERTVAL record");
2065
2066      SmallVector<unsigned, 4> INSERTVALIdx;
2067      for (unsigned RecSize = Record.size();
2068           OpNum != RecSize; ++OpNum) {
2069        uint64_t Index = Record[OpNum];
2070        if ((unsigned)Index != Index)
2071          return Error("Invalid INSERTVAL index");
2072        INSERTVALIdx.push_back((unsigned)Index);
2073      }
2074
2075      I = InsertValueInst::Create(Agg, Val, INSERTVALIdx);
2076      InstructionList.push_back(I);
2077      break;
2078    }
2079
2080    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
2081      // obsolete form of select
2082      // handles select i1 ... in old bitcode
2083      unsigned OpNum = 0;
2084      Value *TrueVal, *FalseVal, *Cond;
2085      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2086          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
2087          getValue(Record, OpNum, Type::getInt1Ty(Context), Cond))
2088        return Error("Invalid SELECT record");
2089
2090      I = SelectInst::Create(Cond, TrueVal, FalseVal);
2091      InstructionList.push_back(I);
2092      break;
2093    }
2094
2095    case bitc::FUNC_CODE_INST_VSELECT: {// VSELECT: [ty,opval,opval,predty,pred]
2096      // new form of select
2097      // handles select i1 or select [N x i1]
2098      unsigned OpNum = 0;
2099      Value *TrueVal, *FalseVal, *Cond;
2100      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2101          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
2102          getValueTypePair(Record, OpNum, NextValueNo, Cond))
2103        return Error("Invalid SELECT record");
2104
2105      // select condition can be either i1 or [N x i1]
2106      if (VectorType* vector_type =
2107          dyn_cast<VectorType>(Cond->getType())) {
2108        // expect <n x i1>
2109        if (vector_type->getElementType() != Type::getInt1Ty(Context))
2110          return Error("Invalid SELECT condition type");
2111      } else {
2112        // expect i1
2113        if (Cond->getType() != Type::getInt1Ty(Context))
2114          return Error("Invalid SELECT condition type");
2115      }
2116
2117      I = SelectInst::Create(Cond, TrueVal, FalseVal);
2118      InstructionList.push_back(I);
2119      break;
2120    }
2121
2122    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
2123      unsigned OpNum = 0;
2124      Value *Vec, *Idx;
2125      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2126          getValue(Record, OpNum, Type::getInt32Ty(Context), Idx))
2127        return Error("Invalid EXTRACTELT record");
2128      I = ExtractElementInst::Create(Vec, Idx);
2129      InstructionList.push_back(I);
2130      break;
2131    }
2132
2133    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
2134      unsigned OpNum = 0;
2135      Value *Vec, *Elt, *Idx;
2136      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2137          getValue(Record, OpNum,
2138                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
2139          getValue(Record, OpNum, Type::getInt32Ty(Context), Idx))
2140        return Error("Invalid INSERTELT record");
2141      I = InsertElementInst::Create(Vec, Elt, Idx);
2142      InstructionList.push_back(I);
2143      break;
2144    }
2145
2146    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
2147      unsigned OpNum = 0;
2148      Value *Vec1, *Vec2, *Mask;
2149      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
2150          getValue(Record, OpNum, Vec1->getType(), Vec2))
2151        return Error("Invalid SHUFFLEVEC record");
2152
2153      if (getValueTypePair(Record, OpNum, NextValueNo, Mask))
2154        return Error("Invalid SHUFFLEVEC record");
2155      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
2156      InstructionList.push_back(I);
2157      break;
2158    }
2159
2160    case bitc::FUNC_CODE_INST_CMP:   // CMP: [opty, opval, opval, pred]
2161      // Old form of ICmp/FCmp returning bool
2162      // Existed to differentiate between icmp/fcmp and vicmp/vfcmp which were
2163      // both legal on vectors but had different behaviour.
2164    case bitc::FUNC_CODE_INST_CMP2: { // CMP2: [opty, opval, opval, pred]
2165      // FCmp/ICmp returning bool or vector of bool
2166
2167      unsigned OpNum = 0;
2168      Value *LHS, *RHS;
2169      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
2170          getValue(Record, OpNum, LHS->getType(), RHS) ||
2171          OpNum+1 != Record.size())
2172        return Error("Invalid CMP record");
2173
2174      if (LHS->getType()->isFPOrFPVectorTy())
2175        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
2176      else
2177        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
2178      InstructionList.push_back(I);
2179      break;
2180    }
2181
2182    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
2183      {
2184        unsigned Size = Record.size();
2185        if (Size == 0) {
2186          I = ReturnInst::Create(Context);
2187          InstructionList.push_back(I);
2188          break;
2189        }
2190
2191        unsigned OpNum = 0;
2192        Value *Op = NULL;
2193        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2194          return Error("Invalid RET record");
2195        if (OpNum != Record.size())
2196          return Error("Invalid RET record");
2197
2198        I = ReturnInst::Create(Context, Op);
2199        InstructionList.push_back(I);
2200        break;
2201      }
2202    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
2203      if (Record.size() != 1 && Record.size() != 3)
2204        return Error("Invalid BR record");
2205      BasicBlock *TrueDest = getBasicBlock(Record[0]);
2206      if (TrueDest == 0)
2207        return Error("Invalid BR record");
2208
2209      if (Record.size() == 1) {
2210        I = BranchInst::Create(TrueDest);
2211        InstructionList.push_back(I);
2212      }
2213      else {
2214        BasicBlock *FalseDest = getBasicBlock(Record[1]);
2215        Value *Cond = getFnValueByID(Record[2], Type::getInt1Ty(Context));
2216        if (FalseDest == 0 || Cond == 0)
2217          return Error("Invalid BR record");
2218        I = BranchInst::Create(TrueDest, FalseDest, Cond);
2219        InstructionList.push_back(I);
2220      }
2221      break;
2222    }
2223    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, op0, op1, ...]
2224      if (Record.size() < 3 || (Record.size() & 1) == 0)
2225        return Error("Invalid SWITCH record");
2226      Type *OpTy = getTypeByID(Record[0]);
2227      Value *Cond = getFnValueByID(Record[1], OpTy);
2228      BasicBlock *Default = getBasicBlock(Record[2]);
2229      if (OpTy == 0 || Cond == 0 || Default == 0)
2230        return Error("Invalid SWITCH record");
2231      unsigned NumCases = (Record.size()-3)/2;
2232      SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
2233      InstructionList.push_back(SI);
2234      for (unsigned i = 0, e = NumCases; i != e; ++i) {
2235        ConstantInt *CaseVal =
2236          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
2237        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
2238        if (CaseVal == 0 || DestBB == 0) {
2239          delete SI;
2240          return Error("Invalid SWITCH record!");
2241        }
2242        SI->addCase(CaseVal, DestBB);
2243      }
2244      I = SI;
2245      break;
2246    }
2247    case bitc::FUNC_CODE_INST_INDIRECTBR: { // INDIRECTBR: [opty, op0, op1, ...]
2248      if (Record.size() < 2)
2249        return Error("Invalid INDIRECTBR record");
2250      Type *OpTy = getTypeByID(Record[0]);
2251      Value *Address = getFnValueByID(Record[1], OpTy);
2252      if (OpTy == 0 || Address == 0)
2253        return Error("Invalid INDIRECTBR record");
2254      unsigned NumDests = Record.size()-2;
2255      IndirectBrInst *IBI = IndirectBrInst::Create(Address, NumDests);
2256      InstructionList.push_back(IBI);
2257      for (unsigned i = 0, e = NumDests; i != e; ++i) {
2258        if (BasicBlock *DestBB = getBasicBlock(Record[2+i])) {
2259          IBI->addDestination(DestBB);
2260        } else {
2261          delete IBI;
2262          return Error("Invalid INDIRECTBR record!");
2263        }
2264      }
2265      I = IBI;
2266      break;
2267    }
2268
2269    case bitc::FUNC_CODE_INST_INVOKE: {
2270      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
2271      if (Record.size() < 4) return Error("Invalid INVOKE record");
2272      AttrListPtr PAL = getAttributes(Record[0]);
2273      unsigned CCInfo = Record[1];
2274      BasicBlock *NormalBB = getBasicBlock(Record[2]);
2275      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
2276
2277      unsigned OpNum = 4;
2278      Value *Callee;
2279      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
2280        return Error("Invalid INVOKE record");
2281
2282      PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
2283      FunctionType *FTy = !CalleeTy ? 0 :
2284        dyn_cast<FunctionType>(CalleeTy->getElementType());
2285
2286      // Check that the right number of fixed parameters are here.
2287      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
2288          Record.size() < OpNum+FTy->getNumParams())
2289        return Error("Invalid INVOKE record");
2290
2291      SmallVector<Value*, 16> Ops;
2292      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
2293        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
2294        if (Ops.back() == 0) return Error("Invalid INVOKE record");
2295      }
2296
2297      if (!FTy->isVarArg()) {
2298        if (Record.size() != OpNum)
2299          return Error("Invalid INVOKE record");
2300      } else {
2301        // Read type/value pairs for varargs params.
2302        while (OpNum != Record.size()) {
2303          Value *Op;
2304          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2305            return Error("Invalid INVOKE record");
2306          Ops.push_back(Op);
2307        }
2308      }
2309
2310      I = InvokeInst::Create(Callee, NormalBB, UnwindBB, Ops);
2311      InstructionList.push_back(I);
2312      cast<InvokeInst>(I)->setCallingConv(
2313        static_cast<CallingConv::ID>(CCInfo));
2314      cast<InvokeInst>(I)->setAttributes(PAL);
2315      break;
2316    }
2317    case bitc::FUNC_CODE_INST_RESUME: { // RESUME: [opval]
2318      unsigned Idx = 0;
2319      Value *Val = 0;
2320      if (getValueTypePair(Record, Idx, NextValueNo, Val))
2321        return Error("Invalid RESUME record");
2322      I = ResumeInst::Create(Val);
2323      InstructionList.push_back(I);
2324      break;
2325    }
2326    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
2327      I = new UnreachableInst(Context);
2328      InstructionList.push_back(I);
2329      break;
2330    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
2331      if (Record.size() < 1 || ((Record.size()-1)&1))
2332        return Error("Invalid PHI record");
2333      Type *Ty = getTypeByID(Record[0]);
2334      if (!Ty) return Error("Invalid PHI record");
2335
2336      PHINode *PN = PHINode::Create(Ty, (Record.size()-1)/2);
2337      InstructionList.push_back(PN);
2338
2339      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
2340        Value *V = getFnValueByID(Record[1+i], Ty);
2341        BasicBlock *BB = getBasicBlock(Record[2+i]);
2342        if (!V || !BB) return Error("Invalid PHI record");
2343        PN->addIncoming(V, BB);
2344      }
2345      I = PN;
2346      break;
2347    }
2348
2349    case bitc::FUNC_CODE_INST_LANDINGPAD: {
2350      // LANDINGPAD: [ty, val, val, num, (id0,val0 ...)?]
2351      unsigned Idx = 0;
2352      if (Record.size() < 4)
2353        return Error("Invalid LANDINGPAD record");
2354      Type *Ty = getTypeByID(Record[Idx++]);
2355      if (!Ty) return Error("Invalid LANDINGPAD record");
2356      Value *PersFn = 0;
2357      if (getValueTypePair(Record, Idx, NextValueNo, PersFn))
2358        return Error("Invalid LANDINGPAD record");
2359
2360      bool IsCleanup = !!Record[Idx++];
2361      unsigned NumClauses = Record[Idx++];
2362      LandingPadInst *LP = LandingPadInst::Create(Ty, PersFn, NumClauses);
2363      LP->setCleanup(IsCleanup);
2364      for (unsigned J = 0; J != NumClauses; ++J) {
2365        LandingPadInst::ClauseType CT =
2366          LandingPadInst::ClauseType(Record[Idx++]); (void)CT;
2367        Value *Val;
2368
2369        if (getValueTypePair(Record, Idx, NextValueNo, Val)) {
2370          delete LP;
2371          return Error("Invalid LANDINGPAD record");
2372        }
2373
2374        assert((CT != LandingPadInst::Catch ||
2375                !isa<ArrayType>(Val->getType())) &&
2376               "Catch clause has a invalid type!");
2377        assert((CT != LandingPadInst::Filter ||
2378                isa<ArrayType>(Val->getType())) &&
2379               "Filter clause has invalid type!");
2380        LP->addClause(Val);
2381      }
2382
2383      I = LP;
2384      InstructionList.push_back(I);
2385      break;
2386    }
2387
2388    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, opty, op, align]
2389      if (Record.size() != 4)
2390        return Error("Invalid ALLOCA record");
2391      PointerType *Ty =
2392        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
2393      Type *OpTy = getTypeByID(Record[1]);
2394      Value *Size = getFnValueByID(Record[2], OpTy);
2395      unsigned Align = Record[3];
2396      if (!Ty || !Size) return Error("Invalid ALLOCA record");
2397      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
2398      InstructionList.push_back(I);
2399      break;
2400    }
2401    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
2402      unsigned OpNum = 0;
2403      Value *Op;
2404      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2405          OpNum+2 != Record.size())
2406        return Error("Invalid LOAD record");
2407
2408      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
2409      InstructionList.push_back(I);
2410      break;
2411    }
2412    case bitc::FUNC_CODE_INST_LOADATOMIC: {
2413       // LOADATOMIC: [opty, op, align, vol, ordering, synchscope]
2414      unsigned OpNum = 0;
2415      Value *Op;
2416      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2417          OpNum+4 != Record.size())
2418        return Error("Invalid LOADATOMIC record");
2419
2420
2421      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2422      if (Ordering == NotAtomic || Ordering == Release ||
2423          Ordering == AcquireRelease)
2424        return Error("Invalid LOADATOMIC record");
2425      if (Ordering != NotAtomic && Record[OpNum] == 0)
2426        return Error("Invalid LOADATOMIC record");
2427      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2428
2429      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1,
2430                       Ordering, SynchScope);
2431      InstructionList.push_back(I);
2432      break;
2433    }
2434    case bitc::FUNC_CODE_INST_STORE: { // STORE2:[ptrty, ptr, val, align, vol]
2435      unsigned OpNum = 0;
2436      Value *Val, *Ptr;
2437      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2438          getValue(Record, OpNum,
2439                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2440          OpNum+2 != Record.size())
2441        return Error("Invalid STORE record");
2442
2443      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
2444      InstructionList.push_back(I);
2445      break;
2446    }
2447    case bitc::FUNC_CODE_INST_STOREATOMIC: {
2448      // STOREATOMIC: [ptrty, ptr, val, align, vol, ordering, synchscope]
2449      unsigned OpNum = 0;
2450      Value *Val, *Ptr;
2451      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2452          getValue(Record, OpNum,
2453                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2454          OpNum+4 != Record.size())
2455        return Error("Invalid STOREATOMIC record");
2456
2457      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2458      if (Ordering == NotAtomic || Ordering == Acquire ||
2459          Ordering == AcquireRelease)
2460        return Error("Invalid STOREATOMIC record");
2461      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2462      if (Ordering != NotAtomic && Record[OpNum] == 0)
2463        return Error("Invalid STOREATOMIC record");
2464
2465      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1,
2466                        Ordering, SynchScope);
2467      InstructionList.push_back(I);
2468      break;
2469    }
2470    case bitc::FUNC_CODE_INST_CMPXCHG: {
2471      // CMPXCHG:[ptrty, ptr, cmp, new, vol, ordering, synchscope]
2472      unsigned OpNum = 0;
2473      Value *Ptr, *Cmp, *New;
2474      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2475          getValue(Record, OpNum,
2476                    cast<PointerType>(Ptr->getType())->getElementType(), Cmp) ||
2477          getValue(Record, OpNum,
2478                    cast<PointerType>(Ptr->getType())->getElementType(), New) ||
2479          OpNum+3 != Record.size())
2480        return Error("Invalid CMPXCHG record");
2481      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+1]);
2482      if (Ordering == NotAtomic || Ordering == Unordered)
2483        return Error("Invalid CMPXCHG record");
2484      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+2]);
2485      I = new AtomicCmpXchgInst(Ptr, Cmp, New, Ordering, SynchScope);
2486      cast<AtomicCmpXchgInst>(I)->setVolatile(Record[OpNum]);
2487      InstructionList.push_back(I);
2488      break;
2489    }
2490    case bitc::FUNC_CODE_INST_ATOMICRMW: {
2491      // ATOMICRMW:[ptrty, ptr, val, op, vol, ordering, synchscope]
2492      unsigned OpNum = 0;
2493      Value *Ptr, *Val;
2494      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2495          getValue(Record, OpNum,
2496                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2497          OpNum+4 != Record.size())
2498        return Error("Invalid ATOMICRMW record");
2499      AtomicRMWInst::BinOp Operation = GetDecodedRMWOperation(Record[OpNum]);
2500      if (Operation < AtomicRMWInst::FIRST_BINOP ||
2501          Operation > AtomicRMWInst::LAST_BINOP)
2502        return Error("Invalid ATOMICRMW record");
2503      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2504      if (Ordering == NotAtomic || Ordering == Unordered)
2505        return Error("Invalid ATOMICRMW record");
2506      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2507      I = new AtomicRMWInst(Operation, Ptr, Val, Ordering, SynchScope);
2508      cast<AtomicRMWInst>(I)->setVolatile(Record[OpNum+1]);
2509      InstructionList.push_back(I);
2510      break;
2511    }
2512    case bitc::FUNC_CODE_INST_FENCE: { // FENCE:[ordering, synchscope]
2513      if (2 != Record.size())
2514        return Error("Invalid FENCE record");
2515      AtomicOrdering Ordering = GetDecodedOrdering(Record[0]);
2516      if (Ordering == NotAtomic || Ordering == Unordered ||
2517          Ordering == Monotonic)
2518        return Error("Invalid FENCE record");
2519      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[1]);
2520      I = new FenceInst(Context, Ordering, SynchScope);
2521      InstructionList.push_back(I);
2522      break;
2523    }
2524    case bitc::FUNC_CODE_INST_CALL: {
2525      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
2526      if (Record.size() < 3)
2527        return Error("Invalid CALL record");
2528
2529      AttrListPtr PAL = getAttributes(Record[0]);
2530      unsigned CCInfo = Record[1];
2531
2532      unsigned OpNum = 2;
2533      Value *Callee;
2534      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
2535        return Error("Invalid CALL record");
2536
2537      PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
2538      FunctionType *FTy = 0;
2539      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
2540      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
2541        return Error("Invalid CALL record");
2542
2543      SmallVector<Value*, 16> Args;
2544      // Read the fixed params.
2545      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
2546        if (FTy->getParamType(i)->isLabelTy())
2547          Args.push_back(getBasicBlock(Record[OpNum]));
2548        else
2549          Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
2550        if (Args.back() == 0) return Error("Invalid CALL record");
2551      }
2552
2553      // Read type/value pairs for varargs params.
2554      if (!FTy->isVarArg()) {
2555        if (OpNum != Record.size())
2556          return Error("Invalid CALL record");
2557      } else {
2558        while (OpNum != Record.size()) {
2559          Value *Op;
2560          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2561            return Error("Invalid CALL record");
2562          Args.push_back(Op);
2563        }
2564      }
2565
2566      I = CallInst::Create(Callee, Args);
2567      InstructionList.push_back(I);
2568      cast<CallInst>(I)->setCallingConv(
2569        static_cast<CallingConv::ID>(CCInfo>>1));
2570      cast<CallInst>(I)->setTailCall(CCInfo & 1);
2571      cast<CallInst>(I)->setAttributes(PAL);
2572      break;
2573    }
2574    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
2575      if (Record.size() < 3)
2576        return Error("Invalid VAARG record");
2577      Type *OpTy = getTypeByID(Record[0]);
2578      Value *Op = getFnValueByID(Record[1], OpTy);
2579      Type *ResTy = getTypeByID(Record[2]);
2580      if (!OpTy || !Op || !ResTy)
2581        return Error("Invalid VAARG record");
2582      I = new VAArgInst(Op, ResTy);
2583      InstructionList.push_back(I);
2584      break;
2585    }
2586    }
2587
2588    // Add instruction to end of current BB.  If there is no current BB, reject
2589    // this file.
2590    if (CurBB == 0) {
2591      delete I;
2592      return Error("Invalid instruction with no BB");
2593    }
2594    CurBB->getInstList().push_back(I);
2595
2596    // If this was a terminator instruction, move to the next block.
2597    if (isa<TerminatorInst>(I)) {
2598      ++CurBBNo;
2599      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
2600    }
2601
2602    // Non-void values get registered in the value table for future use.
2603    if (I && !I->getType()->isVoidTy())
2604      ValueList.AssignValue(I, NextValueNo++);
2605  }
2606
2607  // Check the function list for unresolved values.
2608  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
2609    if (A->getParent() == 0) {
2610      // We found at least one unresolved value.  Nuke them all to avoid leaks.
2611      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
2612        if ((A = dyn_cast<Argument>(ValueList[i])) && A->getParent() == 0) {
2613          A->replaceAllUsesWith(UndefValue::get(A->getType()));
2614          delete A;
2615        }
2616      }
2617      return Error("Never resolved value found in function!");
2618    }
2619  }
2620
2621  // FIXME: Check for unresolved forward-declared metadata references
2622  // and clean up leaks.
2623
2624  // See if anything took the address of blocks in this function.  If so,
2625  // resolve them now.
2626  DenseMap<Function*, std::vector<BlockAddrRefTy> >::iterator BAFRI =
2627    BlockAddrFwdRefs.find(F);
2628  if (BAFRI != BlockAddrFwdRefs.end()) {
2629    std::vector<BlockAddrRefTy> &RefList = BAFRI->second;
2630    for (unsigned i = 0, e = RefList.size(); i != e; ++i) {
2631      unsigned BlockIdx = RefList[i].first;
2632      if (BlockIdx >= FunctionBBs.size())
2633        return Error("Invalid blockaddress block #");
2634
2635      GlobalVariable *FwdRef = RefList[i].second;
2636      FwdRef->replaceAllUsesWith(BlockAddress::get(F, FunctionBBs[BlockIdx]));
2637      FwdRef->eraseFromParent();
2638    }
2639
2640    BlockAddrFwdRefs.erase(BAFRI);
2641  }
2642
2643  // Trim the value list down to the size it was before we parsed this function.
2644  ValueList.shrinkTo(ModuleValueListSize);
2645  MDValueList.shrinkTo(ModuleMDValueListSize);
2646  std::vector<BasicBlock*>().swap(FunctionBBs);
2647  return false;
2648}
2649
2650/// FindFunctionInStream - Find the function body in the bitcode stream
2651bool BitcodeReader::FindFunctionInStream(Function *F,
2652       DenseMap<Function*, uint64_t>::iterator DeferredFunctionInfoIterator) {
2653  while (DeferredFunctionInfoIterator->second == 0) {
2654    if (Stream.AtEndOfStream())
2655      return Error("Could not find Function in stream");
2656    // ParseModule will parse the next body in the stream and set its
2657    // position in the DeferredFunctionInfo map.
2658    if (ParseModule(true)) return true;
2659  }
2660  return false;
2661}
2662
2663//===----------------------------------------------------------------------===//
2664// GVMaterializer implementation
2665//===----------------------------------------------------------------------===//
2666
2667
2668bool BitcodeReader::isMaterializable(const GlobalValue *GV) const {
2669  if (const Function *F = dyn_cast<Function>(GV)) {
2670    return F->isDeclaration() &&
2671      DeferredFunctionInfo.count(const_cast<Function*>(F));
2672  }
2673  return false;
2674}
2675
2676bool BitcodeReader::Materialize(GlobalValue *GV, std::string *ErrInfo) {
2677  Function *F = dyn_cast<Function>(GV);
2678  // If it's not a function or is already material, ignore the request.
2679  if (!F || !F->isMaterializable()) return false;
2680
2681  DenseMap<Function*, uint64_t>::iterator DFII = DeferredFunctionInfo.find(F);
2682  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
2683  // If its position is recorded as 0, its body is somewhere in the stream
2684  // but we haven't seen it yet.
2685  if (DFII->second == 0)
2686    if (LazyStreamer && FindFunctionInStream(F, DFII)) return true;
2687
2688  // Move the bit stream to the saved position of the deferred function body.
2689  Stream.JumpToBit(DFII->second);
2690
2691  if (ParseFunctionBody(F)) {
2692    if (ErrInfo) *ErrInfo = ErrorString;
2693    return true;
2694  }
2695
2696  // Upgrade any old intrinsic calls in the function.
2697  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
2698       E = UpgradedIntrinsics.end(); I != E; ++I) {
2699    if (I->first != I->second) {
2700      for (Value::use_iterator UI = I->first->use_begin(),
2701           UE = I->first->use_end(); UI != UE; ) {
2702        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2703          UpgradeIntrinsicCall(CI, I->second);
2704      }
2705    }
2706  }
2707
2708  return false;
2709}
2710
2711bool BitcodeReader::isDematerializable(const GlobalValue *GV) const {
2712  const Function *F = dyn_cast<Function>(GV);
2713  if (!F || F->isDeclaration())
2714    return false;
2715  return DeferredFunctionInfo.count(const_cast<Function*>(F));
2716}
2717
2718void BitcodeReader::Dematerialize(GlobalValue *GV) {
2719  Function *F = dyn_cast<Function>(GV);
2720  // If this function isn't dematerializable, this is a noop.
2721  if (!F || !isDematerializable(F))
2722    return;
2723
2724  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
2725
2726  // Just forget the function body, we can remat it later.
2727  F->deleteBody();
2728}
2729
2730
2731bool BitcodeReader::MaterializeModule(Module *M, std::string *ErrInfo) {
2732  assert(M == TheModule &&
2733         "Can only Materialize the Module this BitcodeReader is attached to.");
2734  // Iterate over the module, deserializing any functions that are still on
2735  // disk.
2736  for (Module::iterator F = TheModule->begin(), E = TheModule->end();
2737       F != E; ++F)
2738    if (F->isMaterializable() &&
2739        Materialize(F, ErrInfo))
2740      return true;
2741
2742  // At this point, if there are any function bodies, the current bit is
2743  // pointing to the END_BLOCK record after them. Now make sure the rest
2744  // of the bits in the module have been read.
2745  if (NextUnreadBit)
2746    ParseModule(true);
2747
2748  // Upgrade any intrinsic calls that slipped through (should not happen!) and
2749  // delete the old functions to clean up. We can't do this unless the entire
2750  // module is materialized because there could always be another function body
2751  // with calls to the old function.
2752  for (std::vector<std::pair<Function*, Function*> >::iterator I =
2753       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
2754    if (I->first != I->second) {
2755      for (Value::use_iterator UI = I->first->use_begin(),
2756           UE = I->first->use_end(); UI != UE; ) {
2757        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2758          UpgradeIntrinsicCall(CI, I->second);
2759      }
2760      if (!I->first->use_empty())
2761        I->first->replaceAllUsesWith(I->second);
2762      I->first->eraseFromParent();
2763    }
2764  }
2765  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
2766
2767  return false;
2768}
2769
2770bool BitcodeReader::InitStream() {
2771  if (LazyStreamer) return InitLazyStream();
2772  return InitStreamFromBuffer();
2773}
2774
2775bool BitcodeReader::InitStreamFromBuffer() {
2776  const unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
2777  const unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
2778
2779  if (Buffer->getBufferSize() & 3) {
2780    if (!isRawBitcode(BufPtr, BufEnd) && !isBitcodeWrapper(BufPtr, BufEnd))
2781      return Error("Invalid bitcode signature");
2782    else
2783      return Error("Bitcode stream should be a multiple of 4 bytes in length");
2784  }
2785
2786  // If we have a wrapper header, parse it and ignore the non-bc file contents.
2787  // The magic number is 0x0B17C0DE stored in little endian.
2788  if (isBitcodeWrapper(BufPtr, BufEnd))
2789    if (SkipBitcodeWrapperHeader(BufPtr, BufEnd, true))
2790      return Error("Invalid bitcode wrapper header");
2791
2792  StreamFile.reset(new BitstreamReader(BufPtr, BufEnd));
2793  Stream.init(*StreamFile);
2794
2795  return false;
2796}
2797
2798bool BitcodeReader::InitLazyStream() {
2799  // Check and strip off the bitcode wrapper; BitstreamReader expects never to
2800  // see it.
2801  StreamingMemoryObject *Bytes = new StreamingMemoryObject(LazyStreamer);
2802  StreamFile.reset(new BitstreamReader(Bytes));
2803  Stream.init(*StreamFile);
2804
2805  unsigned char buf[16];
2806  if (Bytes->readBytes(0, 16, buf, NULL) == -1)
2807    return Error("Bitcode stream must be at least 16 bytes in length");
2808
2809  if (!isBitcode(buf, buf + 16))
2810    return Error("Invalid bitcode signature");
2811
2812  if (isBitcodeWrapper(buf, buf + 4)) {
2813    const unsigned char *bitcodeStart = buf;
2814    const unsigned char *bitcodeEnd = buf + 16;
2815    SkipBitcodeWrapperHeader(bitcodeStart, bitcodeEnd, false);
2816    Bytes->dropLeadingBytes(bitcodeStart - buf);
2817    Bytes->setKnownObjectSize(bitcodeEnd - bitcodeStart);
2818  }
2819  return false;
2820}
2821
2822//===----------------------------------------------------------------------===//
2823// External interface
2824//===----------------------------------------------------------------------===//
2825
2826/// getLazyBitcodeModule - lazy function-at-a-time loading from a file.
2827///
2828Module *llvm::getLazyBitcodeModule(MemoryBuffer *Buffer,
2829                                   LLVMContext& Context,
2830                                   std::string *ErrMsg) {
2831  Module *M = new Module(Buffer->getBufferIdentifier(), Context);
2832  BitcodeReader *R = new BitcodeReader(Buffer, Context);
2833  M->setMaterializer(R);
2834  if (R->ParseBitcodeInto(M)) {
2835    if (ErrMsg)
2836      *ErrMsg = R->getErrorString();
2837
2838    delete M;  // Also deletes R.
2839    return 0;
2840  }
2841  // Have the BitcodeReader dtor delete 'Buffer'.
2842  R->setBufferOwned(true);
2843
2844  R->materializeForwardReferencedFunctions();
2845
2846  return M;
2847}
2848
2849
2850Module *llvm::getStreamedBitcodeModule(const std::string &name,
2851                                       DataStreamer *streamer,
2852                                       LLVMContext &Context,
2853                                       std::string *ErrMsg) {
2854  Module *M = new Module(name, Context);
2855  BitcodeReader *R = new BitcodeReader(streamer, Context);
2856  M->setMaterializer(R);
2857  if (R->ParseBitcodeInto(M)) {
2858    if (ErrMsg)
2859      *ErrMsg = R->getErrorString();
2860    delete M;  // Also deletes R.
2861    return 0;
2862  }
2863  R->setBufferOwned(false); // no buffer to delete
2864  return M;
2865}
2866
2867/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
2868/// If an error occurs, return null and fill in *ErrMsg if non-null.
2869Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, LLVMContext& Context,
2870                               std::string *ErrMsg){
2871  Module *M = getLazyBitcodeModule(Buffer, Context, ErrMsg);
2872  if (!M) return 0;
2873
2874  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
2875  // there was an error.
2876  static_cast<BitcodeReader*>(M->getMaterializer())->setBufferOwned(false);
2877
2878  // Read in the entire module, and destroy the BitcodeReader.
2879  if (M->MaterializeAllPermanently(ErrMsg)) {
2880    delete M;
2881    return 0;
2882  }
2883
2884  // TODO: Restore the use-lists to the in-memory state when the bitcode was
2885  // written.  We must defer until the Module has been fully materialized.
2886
2887  return M;
2888}
2889
2890std::string llvm::getBitcodeTargetTriple(MemoryBuffer *Buffer,
2891                                         LLVMContext& Context,
2892                                         std::string *ErrMsg) {
2893  BitcodeReader *R = new BitcodeReader(Buffer, Context);
2894  // Don't let the BitcodeReader dtor delete 'Buffer'.
2895  R->setBufferOwned(false);
2896
2897  std::string Triple("");
2898  if (R->ParseTriple(Triple))
2899    if (ErrMsg)
2900      *ErrMsg = R->getErrorString();
2901
2902  delete R;
2903  return Triple;
2904}
2905