BitcodeReader.cpp revision ea693dfab48ee6fc07cc21abc20f487df5057a6b 
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/Instructions.h"
20#include "llvm/Module.h"
21#include "llvm/AutoUpgrade.h"
22#include "llvm/ADT/SmallString.h"
23#include "llvm/ADT/SmallVector.h"
24#include "llvm/Support/MathExtras.h"
25#include "llvm/Support/MemoryBuffer.h"
26#include "llvm/OperandTraits.h"
27using namespace llvm;
28
29void BitcodeReader::FreeState() {
30  delete Buffer;
31  Buffer = 0;
32  std::vector<PATypeHolder>().swap(TypeList);
33  ValueList.clear();
34
35  std::vector<PAListPtr>().swap(ParamAttrs);
36  std::vector<BasicBlock*>().swap(FunctionBBs);
37  std::vector<Function*>().swap(FunctionsWithBodies);
38  DeferredFunctionInfo.clear();
39}
40
41//===----------------------------------------------------------------------===//
42//  Helper functions to implement forward reference resolution, etc.
43//===----------------------------------------------------------------------===//
44
45/// ConvertToString - Convert a string from a record into an std::string, return
46/// true on failure.
47template<typename StrTy>
48static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
49                            StrTy &Result) {
50  if (Idx > Record.size())
51    return true;
52
53  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
54    Result += (char)Record[i];
55  return false;
56}
57
58static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
59  switch (Val) {
60  default: // Map unknown/new linkages to external
61  case 0: return GlobalValue::ExternalLinkage;
62  case 1: return GlobalValue::WeakLinkage;
63  case 2: return GlobalValue::AppendingLinkage;
64  case 3: return GlobalValue::InternalLinkage;
65  case 4: return GlobalValue::LinkOnceLinkage;
66  case 5: return GlobalValue::DLLImportLinkage;
67  case 6: return GlobalValue::DLLExportLinkage;
68  case 7: return GlobalValue::ExternalWeakLinkage;
69  case 8: return GlobalValue::CommonLinkage;
70  }
71}
72
73static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
74  switch (Val) {
75  default: // Map unknown visibilities to default.
76  case 0: return GlobalValue::DefaultVisibility;
77  case 1: return GlobalValue::HiddenVisibility;
78  case 2: return GlobalValue::ProtectedVisibility;
79  }
80}
81
82static int GetDecodedCastOpcode(unsigned Val) {
83  switch (Val) {
84  default: return -1;
85  case bitc::CAST_TRUNC   : return Instruction::Trunc;
86  case bitc::CAST_ZEXT    : return Instruction::ZExt;
87  case bitc::CAST_SEXT    : return Instruction::SExt;
88  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
89  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
90  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
91  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
92  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
93  case bitc::CAST_FPEXT   : return Instruction::FPExt;
94  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
95  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
96  case bitc::CAST_BITCAST : return Instruction::BitCast;
97  }
98}
99static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
100  switch (Val) {
101  default: return -1;
102  case bitc::BINOP_ADD:  return Instruction::Add;
103  case bitc::BINOP_SUB:  return Instruction::Sub;
104  case bitc::BINOP_MUL:  return Instruction::Mul;
105  case bitc::BINOP_UDIV: return Instruction::UDiv;
106  case bitc::BINOP_SDIV:
107    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
108  case bitc::BINOP_UREM: return Instruction::URem;
109  case bitc::BINOP_SREM:
110    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
111  case bitc::BINOP_SHL:  return Instruction::Shl;
112  case bitc::BINOP_LSHR: return Instruction::LShr;
113  case bitc::BINOP_ASHR: return Instruction::AShr;
114  case bitc::BINOP_AND:  return Instruction::And;
115  case bitc::BINOP_OR:   return Instruction::Or;
116  case bitc::BINOP_XOR:  return Instruction::Xor;
117  }
118}
119
120namespace llvm {
121namespace {
122  /// @brief A class for maintaining the slot number definition
123  /// as a placeholder for the actual definition for forward constants defs.
124  class ConstantPlaceHolder : public ConstantExpr {
125    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
126    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
127  public:
128    // allocate space for exactly one operand
129    void *operator new(size_t s) {
130      return User::operator new(s, 1);
131    }
132    explicit ConstantPlaceHolder(const Type *Ty)
133      : ConstantExpr(Ty, Instruction::UserOp1, &Op<0>(), 1) {
134      Op<0>() = UndefValue::get(Type::Int32Ty);
135    }
136
137    /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
138    static inline bool classof(const ConstantPlaceHolder *) { return true; }
139    static bool classof(const Value *V) {
140      return isa<ConstantExpr>(V) &&
141             cast<ConstantExpr>(V)->getOpcode() == Instruction::UserOp1;
142    }
143
144
145    /// Provide fast operand accessors
146    DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
147  };
148}
149
150
151  // FIXME: can we inherit this from ConstantExpr?
152template <>
153struct OperandTraits<ConstantPlaceHolder> : FixedNumOperandTraits<1> {
154};
155
156DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantPlaceHolder, Value)
157}
158
159void BitcodeReaderValueList::resize(unsigned Desired) {
160  if (Desired > Capacity) {
161    // Since we expect many values to come from the bitcode file we better
162    // allocate the double amount, so that the array size grows exponentially
163    // at each reallocation.  Also, add a small amount of 100 extra elements
164    // each time, to reallocate less frequently when the array is still small.
165    //
166    Capacity = Desired * 2 + 100;
167    Use *New = allocHungoffUses(Capacity);
168    Use *Old = OperandList;
169    unsigned Ops = getNumOperands();
170    for (int i(Ops - 1); i >= 0; --i)
171      New[i] = Old[i].get();
172    OperandList = New;
173    if (Old) Use::zap(Old, Old + Ops, true);
174  }
175}
176
177Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
178                                                    const Type *Ty) {
179  if (Idx >= size()) {
180    // Insert a bunch of null values.
181    resize(Idx + 1);
182    NumOperands = Idx+1;
183  }
184
185  if (Value *V = OperandList[Idx]) {
186    assert(Ty == V->getType() && "Type mismatch in constant table!");
187    return cast<Constant>(V);
188  }
189
190  // Create and return a placeholder, which will later be RAUW'd.
191  Constant *C = new ConstantPlaceHolder(Ty);
192  OperandList[Idx] = C;
193  return C;
194}
195
196Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
197  if (Idx >= size()) {
198    // Insert a bunch of null values.
199    resize(Idx + 1);
200    NumOperands = Idx+1;
201  }
202
203  if (Value *V = OperandList[Idx]) {
204    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
205    return V;
206  }
207
208  // No type specified, must be invalid reference.
209  if (Ty == 0) return 0;
210
211  // Create and return a placeholder, which will later be RAUW'd.
212  Value *V = new Argument(Ty);
213  OperandList[Idx] = V;
214  return V;
215}
216
217/// ResolveConstantForwardRefs - Once all constants are read, this method bulk
218/// resolves any forward references.  The idea behind this is that we sometimes
219/// get constants (such as large arrays) which reference *many* forward ref
220/// constants.  Replacing each of these causes a lot of thrashing when
221/// building/reuniquing the constant.  Instead of doing this, we look at all the
222/// uses and rewrite all the place holders at once for any constant that uses
223/// a placeholder.
224void BitcodeReaderValueList::ResolveConstantForwardRefs() {
225  // Sort the values by-pointer so that they are efficient to look up with a
226  // binary search.
227  std::sort(ResolveConstants.begin(), ResolveConstants.end());
228
229  SmallVector<Constant*, 64> NewOps;
230
231  while (!ResolveConstants.empty()) {
232    Value *RealVal = getOperand(ResolveConstants.back().second);
233    Constant *Placeholder = ResolveConstants.back().first;
234    ResolveConstants.pop_back();
235
236    // Loop over all users of the placeholder, updating them to reference the
237    // new value.  If they reference more than one placeholder, update them all
238    // at once.
239    while (!Placeholder->use_empty()) {
240      User *U = Placeholder->use_back();
241      // If the using object isn't uniqued, just update the operands.  This
242      // handles instructions and initializers for global variables.
243      if (!isa<Constant>(U) || isa<GlobalValue>(U)) {
244        U->replaceUsesOfWith(Placeholder, RealVal);
245        continue;
246      }
247
248      // Otherwise, we have a constant that uses the placeholder.  Replace that
249      // constant with a new constant that has *all* placeholder uses updated.
250      Constant *UserC = cast<Constant>(U);
251      for (User::op_iterator I = UserC->op_begin(), E = UserC->op_end();
252           I != E; ++I) {
253        Value *NewOp;
254        if (!isa<ConstantPlaceHolder>(*I)) {
255          // Not a placeholder reference.
256          NewOp = *I;
257        } else if (*I == Placeholder) {
258          // Common case is that it just references this one placeholder.
259          NewOp = RealVal;
260        } else {
261          // Otherwise, look up the placeholder in ResolveConstants.
262          ResolveConstantsTy::iterator It =
263            std::lower_bound(ResolveConstants.begin(), ResolveConstants.end(),
264                             std::pair<Constant*, unsigned>(cast<Constant>(*I),
265                                                            0));
266          assert(It != ResolveConstants.end() && It->first == *I);
267          NewOp = this->getOperand(It->second);
268        }
269
270        NewOps.push_back(cast<Constant>(NewOp));
271      }
272
273      // Make the new constant.
274      Constant *NewC;
275      if (ConstantArray *UserCA = dyn_cast<ConstantArray>(UserC)) {
276        NewC = ConstantArray::get(UserCA->getType(), &NewOps[0], NewOps.size());
277      } else if (ConstantStruct *UserCS = dyn_cast<ConstantStruct>(UserC)) {
278        NewC = ConstantStruct::get(&NewOps[0], NewOps.size(),
279                                   UserCS->getType()->isPacked());
280      } else if (isa<ConstantVector>(UserC)) {
281        NewC = ConstantVector::get(&NewOps[0], NewOps.size());
282      } else {
283        // Must be a constant expression.
284        NewC = cast<ConstantExpr>(UserC)->getWithOperands(&NewOps[0],
285                                                          NewOps.size());
286      }
287
288      UserC->replaceAllUsesWith(NewC);
289      UserC->destroyConstant();
290      NewOps.clear();
291    }
292
293    delete Placeholder;
294  }
295}
296
297
298const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
299  // If the TypeID is in range, return it.
300  if (ID < TypeList.size())
301    return TypeList[ID].get();
302  if (!isTypeTable) return 0;
303
304  // The type table allows forward references.  Push as many Opaque types as
305  // needed to get up to ID.
306  while (TypeList.size() <= ID)
307    TypeList.push_back(OpaqueType::get());
308  return TypeList.back().get();
309}
310
311//===----------------------------------------------------------------------===//
312//  Functions for parsing blocks from the bitcode file
313//===----------------------------------------------------------------------===//
314
315bool BitcodeReader::ParseParamAttrBlock() {
316  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
317    return Error("Malformed block record");
318
319  if (!ParamAttrs.empty())
320    return Error("Multiple PARAMATTR blocks found!");
321
322  SmallVector<uint64_t, 64> Record;
323
324  SmallVector<ParamAttrsWithIndex, 8> Attrs;
325
326  // Read all the records.
327  while (1) {
328    unsigned Code = Stream.ReadCode();
329    if (Code == bitc::END_BLOCK) {
330      if (Stream.ReadBlockEnd())
331        return Error("Error at end of PARAMATTR block");
332      return false;
333    }
334
335    if (Code == bitc::ENTER_SUBBLOCK) {
336      // No known subblocks, always skip them.
337      Stream.ReadSubBlockID();
338      if (Stream.SkipBlock())
339        return Error("Malformed block record");
340      continue;
341    }
342
343    if (Code == bitc::DEFINE_ABBREV) {
344      Stream.ReadAbbrevRecord();
345      continue;
346    }
347
348    // Read a record.
349    Record.clear();
350    switch (Stream.ReadRecord(Code, Record)) {
351    default:  // Default behavior: ignore.
352      break;
353    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
354      if (Record.size() & 1)
355        return Error("Invalid ENTRY record");
356
357      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
358        if (Record[i+1] != ParamAttr::None)
359          Attrs.push_back(ParamAttrsWithIndex::get(Record[i], Record[i+1]));
360      }
361
362      ParamAttrs.push_back(PAListPtr::get(Attrs.begin(), Attrs.end()));
363      Attrs.clear();
364      break;
365    }
366    }
367  }
368}
369
370
371bool BitcodeReader::ParseTypeTable() {
372  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID))
373    return Error("Malformed block record");
374
375  if (!TypeList.empty())
376    return Error("Multiple TYPE_BLOCKs found!");
377
378  SmallVector<uint64_t, 64> Record;
379  unsigned NumRecords = 0;
380
381  // Read all the records for this type table.
382  while (1) {
383    unsigned Code = Stream.ReadCode();
384    if (Code == bitc::END_BLOCK) {
385      if (NumRecords != TypeList.size())
386        return Error("Invalid type forward reference in TYPE_BLOCK");
387      if (Stream.ReadBlockEnd())
388        return Error("Error at end of type table block");
389      return false;
390    }
391
392    if (Code == bitc::ENTER_SUBBLOCK) {
393      // No known subblocks, always skip them.
394      Stream.ReadSubBlockID();
395      if (Stream.SkipBlock())
396        return Error("Malformed block record");
397      continue;
398    }
399
400    if (Code == bitc::DEFINE_ABBREV) {
401      Stream.ReadAbbrevRecord();
402      continue;
403    }
404
405    // Read a record.
406    Record.clear();
407    const Type *ResultTy = 0;
408    switch (Stream.ReadRecord(Code, Record)) {
409    default:  // Default behavior: unknown type.
410      ResultTy = 0;
411      break;
412    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
413      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
414      // type list.  This allows us to reserve space.
415      if (Record.size() < 1)
416        return Error("Invalid TYPE_CODE_NUMENTRY record");
417      TypeList.reserve(Record[0]);
418      continue;
419    case bitc::TYPE_CODE_VOID:      // VOID
420      ResultTy = Type::VoidTy;
421      break;
422    case bitc::TYPE_CODE_FLOAT:     // FLOAT
423      ResultTy = Type::FloatTy;
424      break;
425    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
426      ResultTy = Type::DoubleTy;
427      break;
428    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
429      ResultTy = Type::X86_FP80Ty;
430      break;
431    case bitc::TYPE_CODE_FP128:     // FP128
432      ResultTy = Type::FP128Ty;
433      break;
434    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
435      ResultTy = Type::PPC_FP128Ty;
436      break;
437    case bitc::TYPE_CODE_LABEL:     // LABEL
438      ResultTy = Type::LabelTy;
439      break;
440    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
441      ResultTy = 0;
442      break;
443    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
444      if (Record.size() < 1)
445        return Error("Invalid Integer type record");
446
447      ResultTy = IntegerType::get(Record[0]);
448      break;
449    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
450                                    //          [pointee type, address space]
451      if (Record.size() < 1)
452        return Error("Invalid POINTER type record");
453      unsigned AddressSpace = 0;
454      if (Record.size() == 2)
455        AddressSpace = Record[1];
456      ResultTy = PointerType::get(getTypeByID(Record[0], true), AddressSpace);
457      break;
458    }
459    case bitc::TYPE_CODE_FUNCTION: {
460      // FIXME: attrid is dead, remove it in LLVM 3.0
461      // FUNCTION: [vararg, attrid, retty, paramty x N]
462      if (Record.size() < 3)
463        return Error("Invalid FUNCTION type record");
464      std::vector<const Type*> ArgTys;
465      for (unsigned i = 3, e = Record.size(); i != e; ++i)
466        ArgTys.push_back(getTypeByID(Record[i], true));
467
468      ResultTy = FunctionType::get(getTypeByID(Record[2], true), ArgTys,
469                                   Record[0]);
470      break;
471    }
472    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, eltty x N]
473      if (Record.size() < 1)
474        return Error("Invalid STRUCT type record");
475      std::vector<const Type*> EltTys;
476      for (unsigned i = 1, e = Record.size(); i != e; ++i)
477        EltTys.push_back(getTypeByID(Record[i], true));
478      ResultTy = StructType::get(EltTys, Record[0]);
479      break;
480    }
481    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
482      if (Record.size() < 2)
483        return Error("Invalid ARRAY type record");
484      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
485      break;
486    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
487      if (Record.size() < 2)
488        return Error("Invalid VECTOR type record");
489      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
490      break;
491    }
492
493    if (NumRecords == TypeList.size()) {
494      // If this is a new type slot, just append it.
495      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
496      ++NumRecords;
497    } else if (ResultTy == 0) {
498      // Otherwise, this was forward referenced, so an opaque type was created,
499      // but the result type is actually just an opaque.  Leave the one we
500      // created previously.
501      ++NumRecords;
502    } else {
503      // Otherwise, this was forward referenced, so an opaque type was created.
504      // Resolve the opaque type to the real type now.
505      assert(NumRecords < TypeList.size() && "Typelist imbalance");
506      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
507
508      // Don't directly push the new type on the Tab. Instead we want to replace
509      // the opaque type we previously inserted with the new concrete value. The
510      // refinement from the abstract (opaque) type to the new type causes all
511      // uses of the abstract type to use the concrete type (NewTy). This will
512      // also cause the opaque type to be deleted.
513      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
514
515      // This should have replaced the old opaque type with the new type in the
516      // value table... or with a preexisting type that was already in the
517      // system.  Let's just make sure it did.
518      assert(TypeList[NumRecords-1].get() != OldTy &&
519             "refineAbstractType didn't work!");
520    }
521  }
522}
523
524
525bool BitcodeReader::ParseTypeSymbolTable() {
526  if (Stream.EnterSubBlock(bitc::TYPE_SYMTAB_BLOCK_ID))
527    return Error("Malformed block record");
528
529  SmallVector<uint64_t, 64> Record;
530
531  // Read all the records for this type table.
532  std::string TypeName;
533  while (1) {
534    unsigned Code = Stream.ReadCode();
535    if (Code == bitc::END_BLOCK) {
536      if (Stream.ReadBlockEnd())
537        return Error("Error at end of type symbol table block");
538      return false;
539    }
540
541    if (Code == bitc::ENTER_SUBBLOCK) {
542      // No known subblocks, always skip them.
543      Stream.ReadSubBlockID();
544      if (Stream.SkipBlock())
545        return Error("Malformed block record");
546      continue;
547    }
548
549    if (Code == bitc::DEFINE_ABBREV) {
550      Stream.ReadAbbrevRecord();
551      continue;
552    }
553
554    // Read a record.
555    Record.clear();
556    switch (Stream.ReadRecord(Code, Record)) {
557    default:  // Default behavior: unknown type.
558      break;
559    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namechar x N]
560      if (ConvertToString(Record, 1, TypeName))
561        return Error("Invalid TST_ENTRY record");
562      unsigned TypeID = Record[0];
563      if (TypeID >= TypeList.size())
564        return Error("Invalid Type ID in TST_ENTRY record");
565
566      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
567      TypeName.clear();
568      break;
569    }
570  }
571}
572
573bool BitcodeReader::ParseValueSymbolTable() {
574  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
575    return Error("Malformed block record");
576
577  SmallVector<uint64_t, 64> Record;
578
579  // Read all the records for this value table.
580  SmallString<128> ValueName;
581  while (1) {
582    unsigned Code = Stream.ReadCode();
583    if (Code == bitc::END_BLOCK) {
584      if (Stream.ReadBlockEnd())
585        return Error("Error at end of value symbol table block");
586      return false;
587    }
588    if (Code == bitc::ENTER_SUBBLOCK) {
589      // No known subblocks, always skip them.
590      Stream.ReadSubBlockID();
591      if (Stream.SkipBlock())
592        return Error("Malformed block record");
593      continue;
594    }
595
596    if (Code == bitc::DEFINE_ABBREV) {
597      Stream.ReadAbbrevRecord();
598      continue;
599    }
600
601    // Read a record.
602    Record.clear();
603    switch (Stream.ReadRecord(Code, Record)) {
604    default:  // Default behavior: unknown type.
605      break;
606    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
607      if (ConvertToString(Record, 1, ValueName))
608        return Error("Invalid TST_ENTRY record");
609      unsigned ValueID = Record[0];
610      if (ValueID >= ValueList.size())
611        return Error("Invalid Value ID in VST_ENTRY record");
612      Value *V = ValueList[ValueID];
613
614      V->setName(&ValueName[0], ValueName.size());
615      ValueName.clear();
616      break;
617    }
618    case bitc::VST_CODE_BBENTRY: {
619      if (ConvertToString(Record, 1, ValueName))
620        return Error("Invalid VST_BBENTRY record");
621      BasicBlock *BB = getBasicBlock(Record[0]);
622      if (BB == 0)
623        return Error("Invalid BB ID in VST_BBENTRY record");
624
625      BB->setName(&ValueName[0], ValueName.size());
626      ValueName.clear();
627      break;
628    }
629    }
630  }
631}
632
633/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
634/// the LSB for dense VBR encoding.
635static uint64_t DecodeSignRotatedValue(uint64_t V) {
636  if ((V & 1) == 0)
637    return V >> 1;
638  if (V != 1)
639    return -(V >> 1);
640  // There is no such thing as -0 with integers.  "-0" really means MININT.
641  return 1ULL << 63;
642}
643
644/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
645/// values and aliases that we can.
646bool BitcodeReader::ResolveGlobalAndAliasInits() {
647  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
648  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
649
650  GlobalInitWorklist.swap(GlobalInits);
651  AliasInitWorklist.swap(AliasInits);
652
653  while (!GlobalInitWorklist.empty()) {
654    unsigned ValID = GlobalInitWorklist.back().second;
655    if (ValID >= ValueList.size()) {
656      // Not ready to resolve this yet, it requires something later in the file.
657      GlobalInits.push_back(GlobalInitWorklist.back());
658    } else {
659      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
660        GlobalInitWorklist.back().first->setInitializer(C);
661      else
662        return Error("Global variable initializer is not a constant!");
663    }
664    GlobalInitWorklist.pop_back();
665  }
666
667  while (!AliasInitWorklist.empty()) {
668    unsigned ValID = AliasInitWorklist.back().second;
669    if (ValID >= ValueList.size()) {
670      AliasInits.push_back(AliasInitWorklist.back());
671    } else {
672      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
673        AliasInitWorklist.back().first->setAliasee(C);
674      else
675        return Error("Alias initializer is not a constant!");
676    }
677    AliasInitWorklist.pop_back();
678  }
679  return false;
680}
681
682
683bool BitcodeReader::ParseConstants() {
684  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
685    return Error("Malformed block record");
686
687  SmallVector<uint64_t, 64> Record;
688
689  // Read all the records for this value table.
690  const Type *CurTy = Type::Int32Ty;
691  unsigned NextCstNo = ValueList.size();
692  while (1) {
693    unsigned Code = Stream.ReadCode();
694    if (Code == bitc::END_BLOCK)
695      break;
696
697    if (Code == bitc::ENTER_SUBBLOCK) {
698      // No known subblocks, always skip them.
699      Stream.ReadSubBlockID();
700      if (Stream.SkipBlock())
701        return Error("Malformed block record");
702      continue;
703    }
704
705    if (Code == bitc::DEFINE_ABBREV) {
706      Stream.ReadAbbrevRecord();
707      continue;
708    }
709
710    // Read a record.
711    Record.clear();
712    Value *V = 0;
713    switch (Stream.ReadRecord(Code, Record)) {
714    default:  // Default behavior: unknown constant
715    case bitc::CST_CODE_UNDEF:     // UNDEF
716      V = UndefValue::get(CurTy);
717      break;
718    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
719      if (Record.empty())
720        return Error("Malformed CST_SETTYPE record");
721      if (Record[0] >= TypeList.size())
722        return Error("Invalid Type ID in CST_SETTYPE record");
723      CurTy = TypeList[Record[0]];
724      continue;  // Skip the ValueList manipulation.
725    case bitc::CST_CODE_NULL:      // NULL
726      V = Constant::getNullValue(CurTy);
727      break;
728    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
729      if (!isa<IntegerType>(CurTy) || Record.empty())
730        return Error("Invalid CST_INTEGER record");
731      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
732      break;
733    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
734      if (!isa<IntegerType>(CurTy) || Record.empty())
735        return Error("Invalid WIDE_INTEGER record");
736
737      unsigned NumWords = Record.size();
738      SmallVector<uint64_t, 8> Words;
739      Words.resize(NumWords);
740      for (unsigned i = 0; i != NumWords; ++i)
741        Words[i] = DecodeSignRotatedValue(Record[i]);
742      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
743                                 NumWords, &Words[0]));
744      break;
745    }
746    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
747      if (Record.empty())
748        return Error("Invalid FLOAT record");
749      if (CurTy == Type::FloatTy)
750        V = ConstantFP::get(APFloat(APInt(32, (uint32_t)Record[0])));
751      else if (CurTy == Type::DoubleTy)
752        V = ConstantFP::get(APFloat(APInt(64, Record[0])));
753      else if (CurTy == Type::X86_FP80Ty)
754        V = ConstantFP::get(APFloat(APInt(80, 2, &Record[0])));
755      else if (CurTy == Type::FP128Ty)
756        V = ConstantFP::get(APFloat(APInt(128, 2, &Record[0]), true));
757      else if (CurTy == Type::PPC_FP128Ty)
758        V = ConstantFP::get(APFloat(APInt(128, 2, &Record[0])));
759      else
760        V = UndefValue::get(CurTy);
761      break;
762    }
763
764    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
765      if (Record.empty())
766        return Error("Invalid CST_AGGREGATE record");
767
768      unsigned Size = Record.size();
769      std::vector<Constant*> Elts;
770
771      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
772        for (unsigned i = 0; i != Size; ++i)
773          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
774                                                     STy->getElementType(i)));
775        V = ConstantStruct::get(STy, Elts);
776      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
777        const Type *EltTy = ATy->getElementType();
778        for (unsigned i = 0; i != Size; ++i)
779          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
780        V = ConstantArray::get(ATy, Elts);
781      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
782        const Type *EltTy = VTy->getElementType();
783        for (unsigned i = 0; i != Size; ++i)
784          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
785        V = ConstantVector::get(Elts);
786      } else {
787        V = UndefValue::get(CurTy);
788      }
789      break;
790    }
791    case bitc::CST_CODE_STRING: { // STRING: [values]
792      if (Record.empty())
793        return Error("Invalid CST_AGGREGATE record");
794
795      const ArrayType *ATy = cast<ArrayType>(CurTy);
796      const Type *EltTy = ATy->getElementType();
797
798      unsigned Size = Record.size();
799      std::vector<Constant*> Elts;
800      for (unsigned i = 0; i != Size; ++i)
801        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
802      V = ConstantArray::get(ATy, Elts);
803      break;
804    }
805    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
806      if (Record.empty())
807        return Error("Invalid CST_AGGREGATE record");
808
809      const ArrayType *ATy = cast<ArrayType>(CurTy);
810      const Type *EltTy = ATy->getElementType();
811
812      unsigned Size = Record.size();
813      std::vector<Constant*> Elts;
814      for (unsigned i = 0; i != Size; ++i)
815        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
816      Elts.push_back(Constant::getNullValue(EltTy));
817      V = ConstantArray::get(ATy, Elts);
818      break;
819    }
820    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
821      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
822      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
823      if (Opc < 0) {
824        V = UndefValue::get(CurTy);  // Unknown binop.
825      } else {
826        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
827        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
828        V = ConstantExpr::get(Opc, LHS, RHS);
829      }
830      break;
831    }
832    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
833      if (Record.size() < 3) return Error("Invalid CE_CAST record");
834      int Opc = GetDecodedCastOpcode(Record[0]);
835      if (Opc < 0) {
836        V = UndefValue::get(CurTy);  // Unknown cast.
837      } else {
838        const Type *OpTy = getTypeByID(Record[1]);
839        if (!OpTy) return Error("Invalid CE_CAST record");
840        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
841        V = ConstantExpr::getCast(Opc, Op, CurTy);
842      }
843      break;
844    }
845    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
846      if (Record.size() & 1) return Error("Invalid CE_GEP record");
847      SmallVector<Constant*, 16> Elts;
848      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
849        const Type *ElTy = getTypeByID(Record[i]);
850        if (!ElTy) return Error("Invalid CE_GEP record");
851        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
852      }
853      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
854      break;
855    }
856    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
857      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
858      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
859                                                              Type::Int1Ty),
860                                  ValueList.getConstantFwdRef(Record[1],CurTy),
861                                  ValueList.getConstantFwdRef(Record[2],CurTy));
862      break;
863    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
864      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
865      const VectorType *OpTy =
866        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
867      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
868      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
869      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
870                                                  OpTy->getElementType());
871      V = ConstantExpr::getExtractElement(Op0, Op1);
872      break;
873    }
874    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
875      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
876      if (Record.size() < 3 || OpTy == 0)
877        return Error("Invalid CE_INSERTELT record");
878      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
879      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
880                                                  OpTy->getElementType());
881      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
882      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
883      break;
884    }
885    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
886      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
887      if (Record.size() < 3 || OpTy == 0)
888        return Error("Invalid CE_INSERTELT record");
889      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
890      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
891      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
892      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
893      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
894      break;
895    }
896    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
897      if (Record.size() < 4) return Error("Invalid CE_CMP record");
898      const Type *OpTy = getTypeByID(Record[0]);
899      if (OpTy == 0) return Error("Invalid CE_CMP record");
900      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
901      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
902
903      if (OpTy->isFloatingPoint())
904        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
905      else if (!isa<VectorType>(OpTy))
906        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
907      else if (OpTy->isFPOrFPVector())
908        V = ConstantExpr::getVFCmp(Record[3], Op0, Op1);
909      else
910        V = ConstantExpr::getVICmp(Record[3], Op0, Op1);
911      break;
912    }
913    case bitc::CST_CODE_INLINEASM: {
914      if (Record.size() < 2) return Error("Invalid INLINEASM record");
915      std::string AsmStr, ConstrStr;
916      bool HasSideEffects = Record[0];
917      unsigned AsmStrSize = Record[1];
918      if (2+AsmStrSize >= Record.size())
919        return Error("Invalid INLINEASM record");
920      unsigned ConstStrSize = Record[2+AsmStrSize];
921      if (3+AsmStrSize+ConstStrSize > Record.size())
922        return Error("Invalid INLINEASM record");
923
924      for (unsigned i = 0; i != AsmStrSize; ++i)
925        AsmStr += (char)Record[2+i];
926      for (unsigned i = 0; i != ConstStrSize; ++i)
927        ConstrStr += (char)Record[3+AsmStrSize+i];
928      const PointerType *PTy = cast<PointerType>(CurTy);
929      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
930                         AsmStr, ConstrStr, HasSideEffects);
931      break;
932    }
933    }
934
935    ValueList.AssignValue(V, NextCstNo);
936    ++NextCstNo;
937  }
938
939  if (NextCstNo != ValueList.size())
940    return Error("Invalid constant reference!");
941
942  if (Stream.ReadBlockEnd())
943    return Error("Error at end of constants block");
944
945  // Once all the constants have been read, go through and resolve forward
946  // references.
947  ValueList.ResolveConstantForwardRefs();
948  return false;
949}
950
951/// RememberAndSkipFunctionBody - When we see the block for a function body,
952/// remember where it is and then skip it.  This lets us lazily deserialize the
953/// functions.
954bool BitcodeReader::RememberAndSkipFunctionBody() {
955  // Get the function we are talking about.
956  if (FunctionsWithBodies.empty())
957    return Error("Insufficient function protos");
958
959  Function *Fn = FunctionsWithBodies.back();
960  FunctionsWithBodies.pop_back();
961
962  // Save the current stream state.
963  uint64_t CurBit = Stream.GetCurrentBitNo();
964  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
965
966  // Set the functions linkage to GhostLinkage so we know it is lazily
967  // deserialized.
968  Fn->setLinkage(GlobalValue::GhostLinkage);
969
970  // Skip over the function block for now.
971  if (Stream.SkipBlock())
972    return Error("Malformed block record");
973  return false;
974}
975
976bool BitcodeReader::ParseModule(const std::string &ModuleID) {
977  // Reject multiple MODULE_BLOCK's in a single bitstream.
978  if (TheModule)
979    return Error("Multiple MODULE_BLOCKs in same stream");
980
981  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
982    return Error("Malformed block record");
983
984  // Otherwise, create the module.
985  TheModule = new Module(ModuleID);
986
987  SmallVector<uint64_t, 64> Record;
988  std::vector<std::string> SectionTable;
989  std::vector<std::string> GCTable;
990
991  // Read all the records for this module.
992  while (!Stream.AtEndOfStream()) {
993    unsigned Code = Stream.ReadCode();
994    if (Code == bitc::END_BLOCK) {
995      if (Stream.ReadBlockEnd())
996        return Error("Error at end of module block");
997
998      // Patch the initializers for globals and aliases up.
999      ResolveGlobalAndAliasInits();
1000      if (!GlobalInits.empty() || !AliasInits.empty())
1001        return Error("Malformed global initializer set");
1002      if (!FunctionsWithBodies.empty())
1003        return Error("Too few function bodies found");
1004
1005      // Look for intrinsic functions which need to be upgraded at some point
1006      for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
1007           FI != FE; ++FI) {
1008        Function* NewFn;
1009        if (UpgradeIntrinsicFunction(FI, NewFn))
1010          UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
1011      }
1012
1013      // Force deallocation of memory for these vectors to favor the client that
1014      // want lazy deserialization.
1015      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
1016      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
1017      std::vector<Function*>().swap(FunctionsWithBodies);
1018      return false;
1019    }
1020
1021    if (Code == bitc::ENTER_SUBBLOCK) {
1022      switch (Stream.ReadSubBlockID()) {
1023      default:  // Skip unknown content.
1024        if (Stream.SkipBlock())
1025          return Error("Malformed block record");
1026        break;
1027      case bitc::BLOCKINFO_BLOCK_ID:
1028        if (Stream.ReadBlockInfoBlock())
1029          return Error("Malformed BlockInfoBlock");
1030        break;
1031      case bitc::PARAMATTR_BLOCK_ID:
1032        if (ParseParamAttrBlock())
1033          return true;
1034        break;
1035      case bitc::TYPE_BLOCK_ID:
1036        if (ParseTypeTable())
1037          return true;
1038        break;
1039      case bitc::TYPE_SYMTAB_BLOCK_ID:
1040        if (ParseTypeSymbolTable())
1041          return true;
1042        break;
1043      case bitc::VALUE_SYMTAB_BLOCK_ID:
1044        if (ParseValueSymbolTable())
1045          return true;
1046        break;
1047      case bitc::CONSTANTS_BLOCK_ID:
1048        if (ParseConstants() || ResolveGlobalAndAliasInits())
1049          return true;
1050        break;
1051      case bitc::FUNCTION_BLOCK_ID:
1052        // If this is the first function body we've seen, reverse the
1053        // FunctionsWithBodies list.
1054        if (!HasReversedFunctionsWithBodies) {
1055          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
1056          HasReversedFunctionsWithBodies = true;
1057        }
1058
1059        if (RememberAndSkipFunctionBody())
1060          return true;
1061        break;
1062      }
1063      continue;
1064    }
1065
1066    if (Code == bitc::DEFINE_ABBREV) {
1067      Stream.ReadAbbrevRecord();
1068      continue;
1069    }
1070
1071    // Read a record.
1072    switch (Stream.ReadRecord(Code, Record)) {
1073    default: break;  // Default behavior, ignore unknown content.
1074    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
1075      if (Record.size() < 1)
1076        return Error("Malformed MODULE_CODE_VERSION");
1077      // Only version #0 is supported so far.
1078      if (Record[0] != 0)
1079        return Error("Unknown bitstream version!");
1080      break;
1081    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1082      std::string S;
1083      if (ConvertToString(Record, 0, S))
1084        return Error("Invalid MODULE_CODE_TRIPLE record");
1085      TheModule->setTargetTriple(S);
1086      break;
1087    }
1088    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
1089      std::string S;
1090      if (ConvertToString(Record, 0, S))
1091        return Error("Invalid MODULE_CODE_DATALAYOUT record");
1092      TheModule->setDataLayout(S);
1093      break;
1094    }
1095    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
1096      std::string S;
1097      if (ConvertToString(Record, 0, S))
1098        return Error("Invalid MODULE_CODE_ASM record");
1099      TheModule->setModuleInlineAsm(S);
1100      break;
1101    }
1102    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
1103      std::string S;
1104      if (ConvertToString(Record, 0, S))
1105        return Error("Invalid MODULE_CODE_DEPLIB record");
1106      TheModule->addLibrary(S);
1107      break;
1108    }
1109    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
1110      std::string S;
1111      if (ConvertToString(Record, 0, S))
1112        return Error("Invalid MODULE_CODE_SECTIONNAME record");
1113      SectionTable.push_back(S);
1114      break;
1115    }
1116    case bitc::MODULE_CODE_GCNAME: {  // SECTIONNAME: [strchr x N]
1117      std::string S;
1118      if (ConvertToString(Record, 0, S))
1119        return Error("Invalid MODULE_CODE_GCNAME record");
1120      GCTable.push_back(S);
1121      break;
1122    }
1123    // GLOBALVAR: [pointer type, isconst, initid,
1124    //             linkage, alignment, section, visibility, threadlocal]
1125    case bitc::MODULE_CODE_GLOBALVAR: {
1126      if (Record.size() < 6)
1127        return Error("Invalid MODULE_CODE_GLOBALVAR record");
1128      const Type *Ty = getTypeByID(Record[0]);
1129      if (!isa<PointerType>(Ty))
1130        return Error("Global not a pointer type!");
1131      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
1132      Ty = cast<PointerType>(Ty)->getElementType();
1133
1134      bool isConstant = Record[1];
1135      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1136      unsigned Alignment = (1 << Record[4]) >> 1;
1137      std::string Section;
1138      if (Record[5]) {
1139        if (Record[5]-1 >= SectionTable.size())
1140          return Error("Invalid section ID");
1141        Section = SectionTable[Record[5]-1];
1142      }
1143      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1144      if (Record.size() > 6)
1145        Visibility = GetDecodedVisibility(Record[6]);
1146      bool isThreadLocal = false;
1147      if (Record.size() > 7)
1148        isThreadLocal = Record[7];
1149
1150      GlobalVariable *NewGV =
1151        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule,
1152                           isThreadLocal, AddressSpace);
1153      NewGV->setAlignment(Alignment);
1154      if (!Section.empty())
1155        NewGV->setSection(Section);
1156      NewGV->setVisibility(Visibility);
1157      NewGV->setThreadLocal(isThreadLocal);
1158
1159      ValueList.push_back(NewGV);
1160
1161      // Remember which value to use for the global initializer.
1162      if (unsigned InitID = Record[2])
1163        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1164      break;
1165    }
1166    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1167    //             alignment, section, visibility, gc]
1168    case bitc::MODULE_CODE_FUNCTION: {
1169      if (Record.size() < 8)
1170        return Error("Invalid MODULE_CODE_FUNCTION record");
1171      const Type *Ty = getTypeByID(Record[0]);
1172      if (!isa<PointerType>(Ty))
1173        return Error("Function not a pointer type!");
1174      const FunctionType *FTy =
1175        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1176      if (!FTy)
1177        return Error("Function not a pointer to function type!");
1178
1179      Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
1180                                        "", TheModule);
1181
1182      Func->setCallingConv(Record[1]);
1183      bool isProto = Record[2];
1184      Func->setLinkage(GetDecodedLinkage(Record[3]));
1185      Func->setParamAttrs(getParamAttrs(Record[4]));
1186
1187      Func->setAlignment((1 << Record[5]) >> 1);
1188      if (Record[6]) {
1189        if (Record[6]-1 >= SectionTable.size())
1190          return Error("Invalid section ID");
1191        Func->setSection(SectionTable[Record[6]-1]);
1192      }
1193      Func->setVisibility(GetDecodedVisibility(Record[7]));
1194      if (Record.size() > 8 && Record[8]) {
1195        if (Record[8]-1 > GCTable.size())
1196          return Error("Invalid GC ID");
1197        Func->setGC(GCTable[Record[8]-1].c_str());
1198      }
1199
1200      ValueList.push_back(Func);
1201
1202      // If this is a function with a body, remember the prototype we are
1203      // creating now, so that we can match up the body with them later.
1204      if (!isProto)
1205        FunctionsWithBodies.push_back(Func);
1206      break;
1207    }
1208    // ALIAS: [alias type, aliasee val#, linkage]
1209    // ALIAS: [alias type, aliasee val#, linkage, visibility]
1210    case bitc::MODULE_CODE_ALIAS: {
1211      if (Record.size() < 3)
1212        return Error("Invalid MODULE_ALIAS record");
1213      const Type *Ty = getTypeByID(Record[0]);
1214      if (!isa<PointerType>(Ty))
1215        return Error("Function not a pointer type!");
1216
1217      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1218                                           "", 0, TheModule);
1219      // Old bitcode files didn't have visibility field.
1220      if (Record.size() > 3)
1221        NewGA->setVisibility(GetDecodedVisibility(Record[3]));
1222      ValueList.push_back(NewGA);
1223      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1224      break;
1225    }
1226    /// MODULE_CODE_PURGEVALS: [numvals]
1227    case bitc::MODULE_CODE_PURGEVALS:
1228      // Trim down the value list to the specified size.
1229      if (Record.size() < 1 || Record[0] > ValueList.size())
1230        return Error("Invalid MODULE_PURGEVALS record");
1231      ValueList.shrinkTo(Record[0]);
1232      break;
1233    }
1234    Record.clear();
1235  }
1236
1237  return Error("Premature end of bitstream");
1238}
1239
1240/// SkipWrapperHeader - Some systems wrap bc files with a special header for
1241/// padding or other reasons.  The format of this header is:
1242///
1243/// struct bc_header {
1244///   uint32_t Magic;         // 0x0B17C0DE
1245///   uint32_t Version;       // Version, currently always 0.
1246///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1247///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1248///   ... potentially other gunk ...
1249/// };
1250///
1251/// This function is called when we find a file with a matching magic number.
1252/// In this case, skip down to the subsection of the file that is actually a BC
1253/// file.
1254static bool SkipWrapperHeader(unsigned char *&BufPtr, unsigned char *&BufEnd) {
1255  enum {
1256    KnownHeaderSize = 4*4,  // Size of header we read.
1257    OffsetField = 2*4,      // Offset in bytes to Offset field.
1258    SizeField = 3*4         // Offset in bytes to Size field.
1259  };
1260
1261
1262  // Must contain the header!
1263  if (BufEnd-BufPtr < KnownHeaderSize) return true;
1264
1265  unsigned Offset = ( BufPtr[OffsetField  ]        |
1266                     (BufPtr[OffsetField+1] << 8)  |
1267                     (BufPtr[OffsetField+2] << 16) |
1268                     (BufPtr[OffsetField+3] << 24));
1269  unsigned Size   = ( BufPtr[SizeField    ]        |
1270                     (BufPtr[SizeField  +1] << 8)  |
1271                     (BufPtr[SizeField  +2] << 16) |
1272                     (BufPtr[SizeField  +3] << 24));
1273
1274  // Verify that Offset+Size fits in the file.
1275  if (Offset+Size > unsigned(BufEnd-BufPtr))
1276    return true;
1277  BufPtr += Offset;
1278  BufEnd = BufPtr+Size;
1279  return false;
1280}
1281
1282bool BitcodeReader::ParseBitcode() {
1283  TheModule = 0;
1284
1285  if (Buffer->getBufferSize() & 3)
1286    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1287
1288  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1289  unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
1290
1291  // If we have a wrapper header, parse it and ignore the non-bc file contents.
1292  // The magic number is 0x0B17C0DE stored in little endian.
1293  if (BufPtr != BufEnd && BufPtr[0] == 0xDE && BufPtr[1] == 0xC0 &&
1294      BufPtr[2] == 0x17 && BufPtr[3] == 0x0B)
1295    if (SkipWrapperHeader(BufPtr, BufEnd))
1296      return Error("Invalid bitcode wrapper header");
1297
1298  Stream.init(BufPtr, BufEnd);
1299
1300  // Sniff for the signature.
1301  if (Stream.Read(8) != 'B' ||
1302      Stream.Read(8) != 'C' ||
1303      Stream.Read(4) != 0x0 ||
1304      Stream.Read(4) != 0xC ||
1305      Stream.Read(4) != 0xE ||
1306      Stream.Read(4) != 0xD)
1307    return Error("Invalid bitcode signature");
1308
1309  // We expect a number of well-defined blocks, though we don't necessarily
1310  // need to understand them all.
1311  while (!Stream.AtEndOfStream()) {
1312    unsigned Code = Stream.ReadCode();
1313
1314    if (Code != bitc::ENTER_SUBBLOCK)
1315      return Error("Invalid record at top-level");
1316
1317    unsigned BlockID = Stream.ReadSubBlockID();
1318
1319    // We only know the MODULE subblock ID.
1320    switch (BlockID) {
1321    case bitc::BLOCKINFO_BLOCK_ID:
1322      if (Stream.ReadBlockInfoBlock())
1323        return Error("Malformed BlockInfoBlock");
1324      break;
1325    case bitc::MODULE_BLOCK_ID:
1326      if (ParseModule(Buffer->getBufferIdentifier()))
1327        return true;
1328      break;
1329    default:
1330      if (Stream.SkipBlock())
1331        return Error("Malformed block record");
1332      break;
1333    }
1334  }
1335
1336  return false;
1337}
1338
1339
1340/// ParseFunctionBody - Lazily parse the specified function body block.
1341bool BitcodeReader::ParseFunctionBody(Function *F) {
1342  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1343    return Error("Malformed block record");
1344
1345  unsigned ModuleValueListSize = ValueList.size();
1346
1347  // Add all the function arguments to the value table.
1348  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1349    ValueList.push_back(I);
1350
1351  unsigned NextValueNo = ValueList.size();
1352  BasicBlock *CurBB = 0;
1353  unsigned CurBBNo = 0;
1354
1355  // Read all the records.
1356  SmallVector<uint64_t, 64> Record;
1357  while (1) {
1358    unsigned Code = Stream.ReadCode();
1359    if (Code == bitc::END_BLOCK) {
1360      if (Stream.ReadBlockEnd())
1361        return Error("Error at end of function block");
1362      break;
1363    }
1364
1365    if (Code == bitc::ENTER_SUBBLOCK) {
1366      switch (Stream.ReadSubBlockID()) {
1367      default:  // Skip unknown content.
1368        if (Stream.SkipBlock())
1369          return Error("Malformed block record");
1370        break;
1371      case bitc::CONSTANTS_BLOCK_ID:
1372        if (ParseConstants()) return true;
1373        NextValueNo = ValueList.size();
1374        break;
1375      case bitc::VALUE_SYMTAB_BLOCK_ID:
1376        if (ParseValueSymbolTable()) return true;
1377        break;
1378      }
1379      continue;
1380    }
1381
1382    if (Code == bitc::DEFINE_ABBREV) {
1383      Stream.ReadAbbrevRecord();
1384      continue;
1385    }
1386
1387    // Read a record.
1388    Record.clear();
1389    Instruction *I = 0;
1390    switch (Stream.ReadRecord(Code, Record)) {
1391    default: // Default behavior: reject
1392      return Error("Unknown instruction");
1393    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1394      if (Record.size() < 1 || Record[0] == 0)
1395        return Error("Invalid DECLAREBLOCKS record");
1396      // Create all the basic blocks for the function.
1397      FunctionBBs.resize(Record[0]);
1398      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1399        FunctionBBs[i] = BasicBlock::Create("", F);
1400      CurBB = FunctionBBs[0];
1401      continue;
1402
1403    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1404      unsigned OpNum = 0;
1405      Value *LHS, *RHS;
1406      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1407          getValue(Record, OpNum, LHS->getType(), RHS) ||
1408          OpNum+1 != Record.size())
1409        return Error("Invalid BINOP record");
1410
1411      int Opc = GetDecodedBinaryOpcode(Record[OpNum], LHS->getType());
1412      if (Opc == -1) return Error("Invalid BINOP record");
1413      I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
1414      break;
1415    }
1416    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
1417      unsigned OpNum = 0;
1418      Value *Op;
1419      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1420          OpNum+2 != Record.size())
1421        return Error("Invalid CAST record");
1422
1423      const Type *ResTy = getTypeByID(Record[OpNum]);
1424      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
1425      if (Opc == -1 || ResTy == 0)
1426        return Error("Invalid CAST record");
1427      I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
1428      break;
1429    }
1430    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
1431      unsigned OpNum = 0;
1432      Value *BasePtr;
1433      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
1434        return Error("Invalid GEP record");
1435
1436      SmallVector<Value*, 16> GEPIdx;
1437      while (OpNum != Record.size()) {
1438        Value *Op;
1439        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1440          return Error("Invalid GEP record");
1441        GEPIdx.push_back(Op);
1442      }
1443
1444      I = GetElementPtrInst::Create(BasePtr, GEPIdx.begin(), GEPIdx.end());
1445      break;
1446    }
1447
1448    case bitc::FUNC_CODE_INST_EXTRACTVAL: {
1449                                       // EXTRACTVAL: [opty, opval, n x indices]
1450      unsigned OpNum = 0;
1451      Value *Agg;
1452      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
1453        return Error("Invalid EXTRACTVAL record");
1454
1455      SmallVector<unsigned, 4> EXTRACTVALIdx;
1456      for (unsigned RecSize = Record.size();
1457           OpNum != RecSize; ++OpNum) {
1458        uint64_t Index = Record[OpNum];
1459        if ((unsigned)Index != Index)
1460          return Error("Invalid EXTRACTVAL index");
1461        EXTRACTVALIdx.push_back((unsigned)Index);
1462      }
1463
1464      I = ExtractValueInst::Create(Agg,
1465                                   EXTRACTVALIdx.begin(), EXTRACTVALIdx.end());
1466      break;
1467    }
1468
1469    case bitc::FUNC_CODE_INST_INSERTVAL: {
1470                           // INSERTVAL: [opty, opval, opty, opval, n x indices]
1471      unsigned OpNum = 0;
1472      Value *Agg;
1473      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
1474        return Error("Invalid INSERTVAL record");
1475      Value *Val;
1476      if (getValueTypePair(Record, OpNum, NextValueNo, Val))
1477        return Error("Invalid INSERTVAL record");
1478
1479      SmallVector<unsigned, 4> INSERTVALIdx;
1480      for (unsigned RecSize = Record.size();
1481           OpNum != RecSize; ++OpNum) {
1482        uint64_t Index = Record[OpNum];
1483        if ((unsigned)Index != Index)
1484          return Error("Invalid INSERTVAL index");
1485        INSERTVALIdx.push_back((unsigned)Index);
1486      }
1487
1488      I = InsertValueInst::Create(Agg, Val,
1489                                  INSERTVALIdx.begin(), INSERTVALIdx.end());
1490      break;
1491    }
1492
1493    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
1494      unsigned OpNum = 0;
1495      Value *TrueVal, *FalseVal, *Cond;
1496      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
1497          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
1498          getValue(Record, OpNum, Type::Int1Ty, Cond))
1499        return Error("Invalid SELECT record");
1500
1501      I = SelectInst::Create(Cond, TrueVal, FalseVal);
1502      break;
1503    }
1504
1505    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1506      unsigned OpNum = 0;
1507      Value *Vec, *Idx;
1508      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1509          getValue(Record, OpNum, Type::Int32Ty, Idx))
1510        return Error("Invalid EXTRACTELT record");
1511      I = new ExtractElementInst(Vec, Idx);
1512      break;
1513    }
1514
1515    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1516      unsigned OpNum = 0;
1517      Value *Vec, *Elt, *Idx;
1518      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1519          getValue(Record, OpNum,
1520                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
1521          getValue(Record, OpNum, Type::Int32Ty, Idx))
1522        return Error("Invalid INSERTELT record");
1523      I = InsertElementInst::Create(Vec, Elt, Idx);
1524      break;
1525    }
1526
1527    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
1528      unsigned OpNum = 0;
1529      Value *Vec1, *Vec2, *Mask;
1530      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
1531          getValue(Record, OpNum, Vec1->getType(), Vec2))
1532        return Error("Invalid SHUFFLEVEC record");
1533
1534      const Type *MaskTy =
1535        VectorType::get(Type::Int32Ty,
1536                        cast<VectorType>(Vec1->getType())->getNumElements());
1537
1538      if (getValue(Record, OpNum, MaskTy, Mask))
1539        return Error("Invalid SHUFFLEVEC record");
1540      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1541      break;
1542    }
1543
1544    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1545      unsigned OpNum = 0;
1546      Value *LHS, *RHS;
1547      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1548          getValue(Record, OpNum, LHS->getType(), RHS) ||
1549          OpNum+1 != Record.size())
1550        return Error("Invalid CMP record");
1551
1552      if (LHS->getType()->isFloatingPoint())
1553        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1554      else if (!isa<VectorType>(LHS->getType()))
1555        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1556      else if (LHS->getType()->isFPOrFPVector())
1557        I = new VFCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1558      else
1559        I = new VICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1560      break;
1561    }
1562    case bitc::FUNC_CODE_INST_GETRESULT: { // GETRESULT: [ty, val, n]
1563      if (Record.size() != 2)
1564        return Error("Invalid GETRESULT record");
1565      unsigned OpNum = 0;
1566      Value *Op;
1567      getValueTypePair(Record, OpNum, NextValueNo, Op);
1568      unsigned Index = Record[1];
1569      I = ExtractValueInst::Create(Op, Index);
1570      break;
1571    }
1572
1573    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1574      {
1575        unsigned Size = Record.size();
1576        if (Size == 0) {
1577          I = ReturnInst::Create();
1578          break;
1579        }
1580
1581        unsigned OpNum = 0;
1582        SmallVector<Value *,4> Vs;
1583        do {
1584          Value *Op = NULL;
1585          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1586            return Error("Invalid RET record");
1587          Vs.push_back(Op);
1588        } while(OpNum != Record.size());
1589
1590        const Type *ReturnType = F->getReturnType();
1591        if (Vs.size() > 1 ||
1592            (isa<StructType>(ReturnType) &&
1593             (Vs.empty() || Vs[0]->getType() != ReturnType))) {
1594          Value *RV = UndefValue::get(ReturnType);
1595          for (unsigned i = 0, e = Vs.size(); i != e; ++i) {
1596            I = InsertValueInst::Create(RV, Vs[i], i, "mrv");
1597            CurBB->getInstList().push_back(I);
1598            ValueList.AssignValue(I, NextValueNo++);
1599            RV = I;
1600          }
1601          I = ReturnInst::Create(RV);
1602          break;
1603        }
1604
1605        I = ReturnInst::Create(Vs[0]);
1606        break;
1607      }
1608    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1609      if (Record.size() != 1 && Record.size() != 3)
1610        return Error("Invalid BR record");
1611      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1612      if (TrueDest == 0)
1613        return Error("Invalid BR record");
1614
1615      if (Record.size() == 1)
1616        I = BranchInst::Create(TrueDest);
1617      else {
1618        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1619        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1620        if (FalseDest == 0 || Cond == 0)
1621          return Error("Invalid BR record");
1622        I = BranchInst::Create(TrueDest, FalseDest, Cond);
1623      }
1624      break;
1625    }
1626    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1627      if (Record.size() < 3 || (Record.size() & 1) == 0)
1628        return Error("Invalid SWITCH record");
1629      const Type *OpTy = getTypeByID(Record[0]);
1630      Value *Cond = getFnValueByID(Record[1], OpTy);
1631      BasicBlock *Default = getBasicBlock(Record[2]);
1632      if (OpTy == 0 || Cond == 0 || Default == 0)
1633        return Error("Invalid SWITCH record");
1634      unsigned NumCases = (Record.size()-3)/2;
1635      SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
1636      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1637        ConstantInt *CaseVal =
1638          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1639        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1640        if (CaseVal == 0 || DestBB == 0) {
1641          delete SI;
1642          return Error("Invalid SWITCH record!");
1643        }
1644        SI->addCase(CaseVal, DestBB);
1645      }
1646      I = SI;
1647      break;
1648    }
1649
1650    case bitc::FUNC_CODE_INST_INVOKE: {
1651      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
1652      if (Record.size() < 4) return Error("Invalid INVOKE record");
1653      PAListPtr PAL = getParamAttrs(Record[0]);
1654      unsigned CCInfo = Record[1];
1655      BasicBlock *NormalBB = getBasicBlock(Record[2]);
1656      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
1657
1658      unsigned OpNum = 4;
1659      Value *Callee;
1660      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1661        return Error("Invalid INVOKE record");
1662
1663      const PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
1664      const FunctionType *FTy = !CalleeTy ? 0 :
1665        dyn_cast<FunctionType>(CalleeTy->getElementType());
1666
1667      // Check that the right number of fixed parameters are here.
1668      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
1669          Record.size() < OpNum+FTy->getNumParams())
1670        return Error("Invalid INVOKE record");
1671
1672      SmallVector<Value*, 16> Ops;
1673      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1674        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1675        if (Ops.back() == 0) return Error("Invalid INVOKE record");
1676      }
1677
1678      if (!FTy->isVarArg()) {
1679        if (Record.size() != OpNum)
1680          return Error("Invalid INVOKE record");
1681      } else {
1682        // Read type/value pairs for varargs params.
1683        while (OpNum != Record.size()) {
1684          Value *Op;
1685          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1686            return Error("Invalid INVOKE record");
1687          Ops.push_back(Op);
1688        }
1689      }
1690
1691      I = InvokeInst::Create(Callee, NormalBB, UnwindBB,
1692                             Ops.begin(), Ops.end());
1693      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1694      cast<InvokeInst>(I)->setParamAttrs(PAL);
1695      break;
1696    }
1697    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1698      I = new UnwindInst();
1699      break;
1700    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1701      I = new UnreachableInst();
1702      break;
1703    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
1704      if (Record.size() < 1 || ((Record.size()-1)&1))
1705        return Error("Invalid PHI record");
1706      const Type *Ty = getTypeByID(Record[0]);
1707      if (!Ty) return Error("Invalid PHI record");
1708
1709      PHINode *PN = PHINode::Create(Ty);
1710      PN->reserveOperandSpace((Record.size()-1)/2);
1711
1712      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
1713        Value *V = getFnValueByID(Record[1+i], Ty);
1714        BasicBlock *BB = getBasicBlock(Record[2+i]);
1715        if (!V || !BB) return Error("Invalid PHI record");
1716        PN->addIncoming(V, BB);
1717      }
1718      I = PN;
1719      break;
1720    }
1721
1722    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1723      if (Record.size() < 3)
1724        return Error("Invalid MALLOC record");
1725      const PointerType *Ty =
1726        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1727      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1728      unsigned Align = Record[2];
1729      if (!Ty || !Size) return Error("Invalid MALLOC record");
1730      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1731      break;
1732    }
1733    case bitc::FUNC_CODE_INST_FREE: { // FREE: [op, opty]
1734      unsigned OpNum = 0;
1735      Value *Op;
1736      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1737          OpNum != Record.size())
1738        return Error("Invalid FREE record");
1739      I = new FreeInst(Op);
1740      break;
1741    }
1742    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1743      if (Record.size() < 3)
1744        return Error("Invalid ALLOCA record");
1745      const PointerType *Ty =
1746        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1747      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1748      unsigned Align = Record[2];
1749      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1750      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1751      break;
1752    }
1753    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1754      unsigned OpNum = 0;
1755      Value *Op;
1756      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1757          OpNum+2 != Record.size())
1758        return Error("Invalid LOAD record");
1759
1760      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1761      break;
1762    }
1763    case bitc::FUNC_CODE_INST_STORE2: { // STORE2:[ptrty, ptr, val, align, vol]
1764      unsigned OpNum = 0;
1765      Value *Val, *Ptr;
1766      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
1767          getValue(Record, OpNum,
1768                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
1769          OpNum+2 != Record.size())
1770        return Error("Invalid STORE record");
1771
1772      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1773      break;
1774    }
1775    case bitc::FUNC_CODE_INST_STORE: { // STORE:[val, valty, ptr, align, vol]
1776      // FIXME: Legacy form of store instruction. Should be removed in LLVM 3.0.
1777      unsigned OpNum = 0;
1778      Value *Val, *Ptr;
1779      if (getValueTypePair(Record, OpNum, NextValueNo, Val) ||
1780          getValue(Record, OpNum, PointerType::getUnqual(Val->getType()), Ptr)||
1781          OpNum+2 != Record.size())
1782        return Error("Invalid STORE record");
1783
1784      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1785      break;
1786    }
1787    case bitc::FUNC_CODE_INST_CALL: {
1788      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
1789      if (Record.size() < 3)
1790        return Error("Invalid CALL record");
1791
1792      PAListPtr PAL = getParamAttrs(Record[0]);
1793      unsigned CCInfo = Record[1];
1794
1795      unsigned OpNum = 2;
1796      Value *Callee;
1797      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1798        return Error("Invalid CALL record");
1799
1800      const PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
1801      const FunctionType *FTy = 0;
1802      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1803      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
1804        return Error("Invalid CALL record");
1805
1806      SmallVector<Value*, 16> Args;
1807      // Read the fixed params.
1808      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1809        if (FTy->getParamType(i)->getTypeID()==Type::LabelTyID)
1810          Args.push_back(getBasicBlock(Record[OpNum]));
1811        else
1812          Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1813        if (Args.back() == 0) return Error("Invalid CALL record");
1814      }
1815
1816      // Read type/value pairs for varargs params.
1817      if (!FTy->isVarArg()) {
1818        if (OpNum != Record.size())
1819          return Error("Invalid CALL record");
1820      } else {
1821        while (OpNum != Record.size()) {
1822          Value *Op;
1823          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1824            return Error("Invalid CALL record");
1825          Args.push_back(Op);
1826        }
1827      }
1828
1829      I = CallInst::Create(Callee, Args.begin(), Args.end());
1830      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1831      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1832      cast<CallInst>(I)->setParamAttrs(PAL);
1833      break;
1834    }
1835    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1836      if (Record.size() < 3)
1837        return Error("Invalid VAARG record");
1838      const Type *OpTy = getTypeByID(Record[0]);
1839      Value *Op = getFnValueByID(Record[1], OpTy);
1840      const Type *ResTy = getTypeByID(Record[2]);
1841      if (!OpTy || !Op || !ResTy)
1842        return Error("Invalid VAARG record");
1843      I = new VAArgInst(Op, ResTy);
1844      break;
1845    }
1846    }
1847
1848    // Add instruction to end of current BB.  If there is no current BB, reject
1849    // this file.
1850    if (CurBB == 0) {
1851      delete I;
1852      return Error("Invalid instruction with no BB");
1853    }
1854    CurBB->getInstList().push_back(I);
1855
1856    // If this was a terminator instruction, move to the next block.
1857    if (isa<TerminatorInst>(I)) {
1858      ++CurBBNo;
1859      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1860    }
1861
1862    // Non-void values get registered in the value table for future use.
1863    if (I && I->getType() != Type::VoidTy)
1864      ValueList.AssignValue(I, NextValueNo++);
1865  }
1866
1867  // Check the function list for unresolved values.
1868  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1869    if (A->getParent() == 0) {
1870      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1871      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1872        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1873          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1874          delete A;
1875        }
1876      }
1877      return Error("Never resolved value found in function!");
1878    }
1879  }
1880
1881  // Trim the value list down to the size it was before we parsed this function.
1882  ValueList.shrinkTo(ModuleValueListSize);
1883  std::vector<BasicBlock*>().swap(FunctionBBs);
1884
1885  return false;
1886}
1887
1888//===----------------------------------------------------------------------===//
1889// ModuleProvider implementation
1890//===----------------------------------------------------------------------===//
1891
1892
1893bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1894  // If it already is material, ignore the request.
1895  if (!F->hasNotBeenReadFromBitcode()) return false;
1896
1897  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1898    DeferredFunctionInfo.find(F);
1899  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1900
1901  // Move the bit stream to the saved position of the deferred function body and
1902  // restore the real linkage type for the function.
1903  Stream.JumpToBit(DFII->second.first);
1904  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1905
1906  if (ParseFunctionBody(F)) {
1907    if (ErrInfo) *ErrInfo = ErrorString;
1908    return true;
1909  }
1910
1911  // Upgrade any old intrinsic calls in the function.
1912  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
1913       E = UpgradedIntrinsics.end(); I != E; ++I) {
1914    if (I->first != I->second) {
1915      for (Value::use_iterator UI = I->first->use_begin(),
1916           UE = I->first->use_end(); UI != UE; ) {
1917        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1918          UpgradeIntrinsicCall(CI, I->second);
1919      }
1920    }
1921  }
1922
1923  return false;
1924}
1925
1926void BitcodeReader::dematerializeFunction(Function *F) {
1927  // If this function isn't materialized, or if it is a proto, this is a noop.
1928  if (F->hasNotBeenReadFromBitcode() || F->isDeclaration())
1929    return;
1930
1931  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
1932
1933  // Just forget the function body, we can remat it later.
1934  F->deleteBody();
1935  F->setLinkage(GlobalValue::GhostLinkage);
1936}
1937
1938
1939Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
1940  for (DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1941       DeferredFunctionInfo.begin(), E = DeferredFunctionInfo.end(); I != E;
1942       ++I) {
1943    Function *F = I->first;
1944    if (F->hasNotBeenReadFromBitcode() &&
1945        materializeFunction(F, ErrInfo))
1946      return 0;
1947  }
1948
1949  // Upgrade any intrinsic calls that slipped through (should not happen!) and
1950  // delete the old functions to clean up. We can't do this unless the entire
1951  // module is materialized because there could always be another function body
1952  // with calls to the old function.
1953  for (std::vector<std::pair<Function*, Function*> >::iterator I =
1954       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
1955    if (I->first != I->second) {
1956      for (Value::use_iterator UI = I->first->use_begin(),
1957           UE = I->first->use_end(); UI != UE; ) {
1958        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1959          UpgradeIntrinsicCall(CI, I->second);
1960      }
1961      ValueList.replaceUsesOfWith(I->first, I->second);
1962      I->first->eraseFromParent();
1963    }
1964  }
1965  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
1966
1967  return TheModule;
1968}
1969
1970
1971/// This method is provided by the parent ModuleProvde class and overriden
1972/// here. It simply releases the module from its provided and frees up our
1973/// state.
1974/// @brief Release our hold on the generated module
1975Module *BitcodeReader::releaseModule(std::string *ErrInfo) {
1976  // Since we're losing control of this Module, we must hand it back complete
1977  Module *M = ModuleProvider::releaseModule(ErrInfo);
1978  FreeState();
1979  return M;
1980}
1981
1982
1983//===----------------------------------------------------------------------===//
1984// External interface
1985//===----------------------------------------------------------------------===//
1986
1987/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1988///
1989ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1990                                               std::string *ErrMsg) {
1991  BitcodeReader *R = new BitcodeReader(Buffer);
1992  if (R->ParseBitcode()) {
1993    if (ErrMsg)
1994      *ErrMsg = R->getErrorString();
1995
1996    // Don't let the BitcodeReader dtor delete 'Buffer'.
1997    R->releaseMemoryBuffer();
1998    delete R;
1999    return 0;
2000  }
2001  return R;
2002}
2003
2004/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
2005/// If an error occurs, return null and fill in *ErrMsg if non-null.
2006Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
2007  BitcodeReader *R;
2008  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
2009  if (!R) return 0;
2010
2011  // Read in the entire module.
2012  Module *M = R->materializeModule(ErrMsg);
2013
2014  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
2015  // there was an error.
2016  R->releaseMemoryBuffer();
2017
2018  // If there was no error, tell ModuleProvider not to delete it when its dtor
2019  // is run.
2020  if (M)
2021    M = R->releaseModule(ErrMsg);
2022
2023  delete R;
2024  return M;
2025}
2026