BitcodeReader.cpp revision baa64ebd26d1788a1824c8855a54123dcb9e8668 
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  }
70}
71
72static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
73  switch (Val) {
74  default: // Map unknown visibilities to default.
75  case 0: return GlobalValue::DefaultVisibility;
76  case 1: return GlobalValue::HiddenVisibility;
77  case 2: return GlobalValue::ProtectedVisibility;
78  }
79}
80
81static int GetDecodedCastOpcode(unsigned Val) {
82  switch (Val) {
83  default: return -1;
84  case bitc::CAST_TRUNC   : return Instruction::Trunc;
85  case bitc::CAST_ZEXT    : return Instruction::ZExt;
86  case bitc::CAST_SEXT    : return Instruction::SExt;
87  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
88  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
89  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
90  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
91  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
92  case bitc::CAST_FPEXT   : return Instruction::FPExt;
93  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
94  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
95  case bitc::CAST_BITCAST : return Instruction::BitCast;
96  }
97}
98static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
99  switch (Val) {
100  default: return -1;
101  case bitc::BINOP_ADD:  return Instruction::Add;
102  case bitc::BINOP_SUB:  return Instruction::Sub;
103  case bitc::BINOP_MUL:  return Instruction::Mul;
104  case bitc::BINOP_UDIV: return Instruction::UDiv;
105  case bitc::BINOP_SDIV:
106    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
107  case bitc::BINOP_UREM: return Instruction::URem;
108  case bitc::BINOP_SREM:
109    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
110  case bitc::BINOP_SHL:  return Instruction::Shl;
111  case bitc::BINOP_LSHR: return Instruction::LShr;
112  case bitc::BINOP_ASHR: return Instruction::AShr;
113  case bitc::BINOP_AND:  return Instruction::And;
114  case bitc::BINOP_OR:   return Instruction::Or;
115  case bitc::BINOP_XOR:  return Instruction::Xor;
116  }
117}
118
119namespace llvm {
120namespace {
121  /// @brief A class for maintaining the slot number definition
122  /// as a placeholder for the actual definition for forward constants defs.
123  class ConstantPlaceHolder : public ConstantExpr {
124    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
125    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
126  public:
127    // allocate space for exactly one operand
128    void *operator new(size_t s) {
129      return User::operator new(s, 1);
130    }
131    explicit ConstantPlaceHolder(const Type *Ty)
132      : ConstantExpr(Ty, Instruction::UserOp1, &Op<0>(), 1) {
133      Op<0>() = UndefValue::get(Type::Int32Ty);
134    }
135    /// Provide fast operand accessors
136    DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
137  };
138}
139
140
141  // FIXME: can we inherit this from ConstantExpr?
142template <>
143struct OperandTraits<ConstantPlaceHolder> : FixedNumOperandTraits<1> {
144};
145
146DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantPlaceHolder, Value)
147}
148
149void BitcodeReaderValueList::resize(unsigned Desired) {
150  if (Desired > Capacity) {
151    // Since we expect many values to come from the bitcode file we better
152    // allocate the double amount, so that the array size grows exponentially
153    // at each reallocation.  Also, add a small amount of 100 extra elements
154    // each time, to reallocate less frequently when the array is still small.
155    //
156    Capacity = Desired * 2 + 100;
157    Use *New = allocHungoffUses(Capacity);
158    Use *Old = OperandList;
159    unsigned Ops = getNumOperands();
160    for (int i(Ops - 1); i >= 0; --i)
161      New[i] = Old[i].get();
162    OperandList = New;
163    if (Old) Use::zap(Old, Old + Ops, true);
164  }
165}
166
167Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
168                                                    const Type *Ty) {
169  if (Idx >= size()) {
170    // Insert a bunch of null values.
171    resize(Idx + 1);
172    NumOperands = Idx+1;
173  }
174
175  if (Value *V = OperandList[Idx]) {
176    assert(Ty == V->getType() && "Type mismatch in constant table!");
177    return cast<Constant>(V);
178  }
179
180  // Create and return a placeholder, which will later be RAUW'd.
181  Constant *C = new ConstantPlaceHolder(Ty);
182  OperandList[Idx].init(C, this);
183  return C;
184}
185
186Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
187  if (Idx >= size()) {
188    // Insert a bunch of null values.
189    resize(Idx + 1);
190    NumOperands = Idx+1;
191  }
192
193  if (Value *V = OperandList[Idx]) {
194    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
195    return V;
196  }
197
198  // No type specified, must be invalid reference.
199  if (Ty == 0) return 0;
200
201  // Create and return a placeholder, which will later be RAUW'd.
202  Value *V = new Argument(Ty);
203  OperandList[Idx].init(V, this);
204  return V;
205}
206
207
208const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
209  // If the TypeID is in range, return it.
210  if (ID < TypeList.size())
211    return TypeList[ID].get();
212  if (!isTypeTable) return 0;
213
214  // The type table allows forward references.  Push as many Opaque types as
215  // needed to get up to ID.
216  while (TypeList.size() <= ID)
217    TypeList.push_back(OpaqueType::get());
218  return TypeList.back().get();
219}
220
221//===----------------------------------------------------------------------===//
222//  Functions for parsing blocks from the bitcode file
223//===----------------------------------------------------------------------===//
224
225bool BitcodeReader::ParseParamAttrBlock() {
226  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
227    return Error("Malformed block record");
228
229  if (!ParamAttrs.empty())
230    return Error("Multiple PARAMATTR blocks found!");
231
232  SmallVector<uint64_t, 64> Record;
233
234  SmallVector<ParamAttrsWithIndex, 8> Attrs;
235
236  // Read all the records.
237  while (1) {
238    unsigned Code = Stream.ReadCode();
239    if (Code == bitc::END_BLOCK) {
240      if (Stream.ReadBlockEnd())
241        return Error("Error at end of PARAMATTR block");
242      return false;
243    }
244
245    if (Code == bitc::ENTER_SUBBLOCK) {
246      // No known subblocks, always skip them.
247      Stream.ReadSubBlockID();
248      if (Stream.SkipBlock())
249        return Error("Malformed block record");
250      continue;
251    }
252
253    if (Code == bitc::DEFINE_ABBREV) {
254      Stream.ReadAbbrevRecord();
255      continue;
256    }
257
258    // Read a record.
259    Record.clear();
260    switch (Stream.ReadRecord(Code, Record)) {
261    default:  // Default behavior: ignore.
262      break;
263    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
264      if (Record.size() & 1)
265        return Error("Invalid ENTRY record");
266
267      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
268        if (Record[i+1] != ParamAttr::None)
269          Attrs.push_back(ParamAttrsWithIndex::get(Record[i], Record[i+1]));
270      }
271
272      ParamAttrs.push_back(PAListPtr::get(Attrs.begin(), Attrs.end()));
273      Attrs.clear();
274      break;
275    }
276    }
277  }
278}
279
280
281bool BitcodeReader::ParseTypeTable() {
282  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID))
283    return Error("Malformed block record");
284
285  if (!TypeList.empty())
286    return Error("Multiple TYPE_BLOCKs found!");
287
288  SmallVector<uint64_t, 64> Record;
289  unsigned NumRecords = 0;
290
291  // Read all the records for this type table.
292  while (1) {
293    unsigned Code = Stream.ReadCode();
294    if (Code == bitc::END_BLOCK) {
295      if (NumRecords != TypeList.size())
296        return Error("Invalid type forward reference in TYPE_BLOCK");
297      if (Stream.ReadBlockEnd())
298        return Error("Error at end of type table block");
299      return false;
300    }
301
302    if (Code == bitc::ENTER_SUBBLOCK) {
303      // No known subblocks, always skip them.
304      Stream.ReadSubBlockID();
305      if (Stream.SkipBlock())
306        return Error("Malformed block record");
307      continue;
308    }
309
310    if (Code == bitc::DEFINE_ABBREV) {
311      Stream.ReadAbbrevRecord();
312      continue;
313    }
314
315    // Read a record.
316    Record.clear();
317    const Type *ResultTy = 0;
318    switch (Stream.ReadRecord(Code, Record)) {
319    default:  // Default behavior: unknown type.
320      ResultTy = 0;
321      break;
322    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
323      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
324      // type list.  This allows us to reserve space.
325      if (Record.size() < 1)
326        return Error("Invalid TYPE_CODE_NUMENTRY record");
327      TypeList.reserve(Record[0]);
328      continue;
329    case bitc::TYPE_CODE_VOID:      // VOID
330      ResultTy = Type::VoidTy;
331      break;
332    case bitc::TYPE_CODE_FLOAT:     // FLOAT
333      ResultTy = Type::FloatTy;
334      break;
335    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
336      ResultTy = Type::DoubleTy;
337      break;
338    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
339      ResultTy = Type::X86_FP80Ty;
340      break;
341    case bitc::TYPE_CODE_FP128:     // FP128
342      ResultTy = Type::FP128Ty;
343      break;
344    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
345      ResultTy = Type::PPC_FP128Ty;
346      break;
347    case bitc::TYPE_CODE_LABEL:     // LABEL
348      ResultTy = Type::LabelTy;
349      break;
350    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
351      ResultTy = 0;
352      break;
353    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
354      if (Record.size() < 1)
355        return Error("Invalid Integer type record");
356
357      ResultTy = IntegerType::get(Record[0]);
358      break;
359    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
360                                    //          [pointee type, address space]
361      if (Record.size() < 1)
362        return Error("Invalid POINTER type record");
363      unsigned AddressSpace = 0;
364      if (Record.size() == 2)
365        AddressSpace = Record[1];
366      ResultTy = PointerType::get(getTypeByID(Record[0], true), AddressSpace);
367      break;
368    }
369    case bitc::TYPE_CODE_FUNCTION: {
370      // FIXME: attrid is dead, remove it in LLVM 3.0
371      // FUNCTION: [vararg, attrid, retty, paramty x N]
372      if (Record.size() < 3)
373        return Error("Invalid FUNCTION type record");
374      std::vector<const Type*> ArgTys;
375      for (unsigned i = 3, e = Record.size(); i != e; ++i)
376        ArgTys.push_back(getTypeByID(Record[i], true));
377
378      ResultTy = FunctionType::get(getTypeByID(Record[2], true), ArgTys,
379                                   Record[0]);
380      break;
381    }
382    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, eltty x N]
383      if (Record.size() < 1)
384        return Error("Invalid STRUCT type record");
385      std::vector<const Type*> EltTys;
386      for (unsigned i = 1, e = Record.size(); i != e; ++i)
387        EltTys.push_back(getTypeByID(Record[i], true));
388      ResultTy = StructType::get(EltTys, Record[0]);
389      break;
390    }
391    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
392      if (Record.size() < 2)
393        return Error("Invalid ARRAY type record");
394      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
395      break;
396    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
397      if (Record.size() < 2)
398        return Error("Invalid VECTOR type record");
399      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
400      break;
401    }
402
403    if (NumRecords == TypeList.size()) {
404      // If this is a new type slot, just append it.
405      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
406      ++NumRecords;
407    } else if (ResultTy == 0) {
408      // Otherwise, this was forward referenced, so an opaque type was created,
409      // but the result type is actually just an opaque.  Leave the one we
410      // created previously.
411      ++NumRecords;
412    } else {
413      // Otherwise, this was forward referenced, so an opaque type was created.
414      // Resolve the opaque type to the real type now.
415      assert(NumRecords < TypeList.size() && "Typelist imbalance");
416      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
417
418      // Don't directly push the new type on the Tab. Instead we want to replace
419      // the opaque type we previously inserted with the new concrete value. The
420      // refinement from the abstract (opaque) type to the new type causes all
421      // uses of the abstract type to use the concrete type (NewTy). This will
422      // also cause the opaque type to be deleted.
423      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
424
425      // This should have replaced the old opaque type with the new type in the
426      // value table... or with a preexisting type that was already in the
427      // system.  Let's just make sure it did.
428      assert(TypeList[NumRecords-1].get() != OldTy &&
429             "refineAbstractType didn't work!");
430    }
431  }
432}
433
434
435bool BitcodeReader::ParseTypeSymbolTable() {
436  if (Stream.EnterSubBlock(bitc::TYPE_SYMTAB_BLOCK_ID))
437    return Error("Malformed block record");
438
439  SmallVector<uint64_t, 64> Record;
440
441  // Read all the records for this type table.
442  std::string TypeName;
443  while (1) {
444    unsigned Code = Stream.ReadCode();
445    if (Code == bitc::END_BLOCK) {
446      if (Stream.ReadBlockEnd())
447        return Error("Error at end of type symbol table block");
448      return false;
449    }
450
451    if (Code == bitc::ENTER_SUBBLOCK) {
452      // No known subblocks, always skip them.
453      Stream.ReadSubBlockID();
454      if (Stream.SkipBlock())
455        return Error("Malformed block record");
456      continue;
457    }
458
459    if (Code == bitc::DEFINE_ABBREV) {
460      Stream.ReadAbbrevRecord();
461      continue;
462    }
463
464    // Read a record.
465    Record.clear();
466    switch (Stream.ReadRecord(Code, Record)) {
467    default:  // Default behavior: unknown type.
468      break;
469    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namechar x N]
470      if (ConvertToString(Record, 1, TypeName))
471        return Error("Invalid TST_ENTRY record");
472      unsigned TypeID = Record[0];
473      if (TypeID >= TypeList.size())
474        return Error("Invalid Type ID in TST_ENTRY record");
475
476      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
477      TypeName.clear();
478      break;
479    }
480  }
481}
482
483bool BitcodeReader::ParseValueSymbolTable() {
484  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
485    return Error("Malformed block record");
486
487  SmallVector<uint64_t, 64> Record;
488
489  // Read all the records for this value table.
490  SmallString<128> ValueName;
491  while (1) {
492    unsigned Code = Stream.ReadCode();
493    if (Code == bitc::END_BLOCK) {
494      if (Stream.ReadBlockEnd())
495        return Error("Error at end of value symbol table block");
496      return false;
497    }
498    if (Code == bitc::ENTER_SUBBLOCK) {
499      // No known subblocks, always skip them.
500      Stream.ReadSubBlockID();
501      if (Stream.SkipBlock())
502        return Error("Malformed block record");
503      continue;
504    }
505
506    if (Code == bitc::DEFINE_ABBREV) {
507      Stream.ReadAbbrevRecord();
508      continue;
509    }
510
511    // Read a record.
512    Record.clear();
513    switch (Stream.ReadRecord(Code, Record)) {
514    default:  // Default behavior: unknown type.
515      break;
516    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
517      if (ConvertToString(Record, 1, ValueName))
518        return Error("Invalid TST_ENTRY record");
519      unsigned ValueID = Record[0];
520      if (ValueID >= ValueList.size())
521        return Error("Invalid Value ID in VST_ENTRY record");
522      Value *V = ValueList[ValueID];
523
524      V->setName(&ValueName[0], ValueName.size());
525      ValueName.clear();
526      break;
527    }
528    case bitc::VST_CODE_BBENTRY: {
529      if (ConvertToString(Record, 1, ValueName))
530        return Error("Invalid VST_BBENTRY record");
531      BasicBlock *BB = getBasicBlock(Record[0]);
532      if (BB == 0)
533        return Error("Invalid BB ID in VST_BBENTRY record");
534
535      BB->setName(&ValueName[0], ValueName.size());
536      ValueName.clear();
537      break;
538    }
539    }
540  }
541}
542
543/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
544/// the LSB for dense VBR encoding.
545static uint64_t DecodeSignRotatedValue(uint64_t V) {
546  if ((V & 1) == 0)
547    return V >> 1;
548  if (V != 1)
549    return -(V >> 1);
550  // There is no such thing as -0 with integers.  "-0" really means MININT.
551  return 1ULL << 63;
552}
553
554/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
555/// values and aliases that we can.
556bool BitcodeReader::ResolveGlobalAndAliasInits() {
557  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
558  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
559
560  GlobalInitWorklist.swap(GlobalInits);
561  AliasInitWorklist.swap(AliasInits);
562
563  while (!GlobalInitWorklist.empty()) {
564    unsigned ValID = GlobalInitWorklist.back().second;
565    if (ValID >= ValueList.size()) {
566      // Not ready to resolve this yet, it requires something later in the file.
567      GlobalInits.push_back(GlobalInitWorklist.back());
568    } else {
569      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
570        GlobalInitWorklist.back().first->setInitializer(C);
571      else
572        return Error("Global variable initializer is not a constant!");
573    }
574    GlobalInitWorklist.pop_back();
575  }
576
577  while (!AliasInitWorklist.empty()) {
578    unsigned ValID = AliasInitWorklist.back().second;
579    if (ValID >= ValueList.size()) {
580      AliasInits.push_back(AliasInitWorklist.back());
581    } else {
582      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
583        AliasInitWorklist.back().first->setAliasee(C);
584      else
585        return Error("Alias initializer is not a constant!");
586    }
587    AliasInitWorklist.pop_back();
588  }
589  return false;
590}
591
592
593bool BitcodeReader::ParseConstants() {
594  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
595    return Error("Malformed block record");
596
597  SmallVector<uint64_t, 64> Record;
598
599  // Read all the records for this value table.
600  const Type *CurTy = Type::Int32Ty;
601  unsigned NextCstNo = ValueList.size();
602  while (1) {
603    unsigned Code = Stream.ReadCode();
604    if (Code == bitc::END_BLOCK) {
605      if (NextCstNo != ValueList.size())
606        return Error("Invalid constant reference!");
607
608      if (Stream.ReadBlockEnd())
609        return Error("Error at end of constants block");
610      return false;
611    }
612
613    if (Code == bitc::ENTER_SUBBLOCK) {
614      // No known subblocks, always skip them.
615      Stream.ReadSubBlockID();
616      if (Stream.SkipBlock())
617        return Error("Malformed block record");
618      continue;
619    }
620
621    if (Code == bitc::DEFINE_ABBREV) {
622      Stream.ReadAbbrevRecord();
623      continue;
624    }
625
626    // Read a record.
627    Record.clear();
628    Value *V = 0;
629    switch (Stream.ReadRecord(Code, Record)) {
630    default:  // Default behavior: unknown constant
631    case bitc::CST_CODE_UNDEF:     // UNDEF
632      V = UndefValue::get(CurTy);
633      break;
634    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
635      if (Record.empty())
636        return Error("Malformed CST_SETTYPE record");
637      if (Record[0] >= TypeList.size())
638        return Error("Invalid Type ID in CST_SETTYPE record");
639      CurTy = TypeList[Record[0]];
640      continue;  // Skip the ValueList manipulation.
641    case bitc::CST_CODE_NULL:      // NULL
642      V = Constant::getNullValue(CurTy);
643      break;
644    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
645      if (!isa<IntegerType>(CurTy) || Record.empty())
646        return Error("Invalid CST_INTEGER record");
647      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
648      break;
649    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
650      if (!isa<IntegerType>(CurTy) || Record.empty())
651        return Error("Invalid WIDE_INTEGER record");
652
653      unsigned NumWords = Record.size();
654      SmallVector<uint64_t, 8> Words;
655      Words.resize(NumWords);
656      for (unsigned i = 0; i != NumWords; ++i)
657        Words[i] = DecodeSignRotatedValue(Record[i]);
658      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
659                                 NumWords, &Words[0]));
660      break;
661    }
662    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
663      if (Record.empty())
664        return Error("Invalid FLOAT record");
665      if (CurTy == Type::FloatTy)
666        V = ConstantFP::get(APFloat(APInt(32, (uint32_t)Record[0])));
667      else if (CurTy == Type::DoubleTy)
668        V = ConstantFP::get(APFloat(APInt(64, Record[0])));
669      else if (CurTy == Type::X86_FP80Ty)
670        V = ConstantFP::get(APFloat(APInt(80, 2, &Record[0])));
671      else if (CurTy == Type::FP128Ty)
672        V = ConstantFP::get(APFloat(APInt(128, 2, &Record[0]), true));
673      else if (CurTy == Type::PPC_FP128Ty)
674        V = ConstantFP::get(APFloat(APInt(128, 2, &Record[0])));
675      else
676        V = UndefValue::get(CurTy);
677      break;
678    }
679
680    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
681      if (Record.empty())
682        return Error("Invalid CST_AGGREGATE record");
683
684      unsigned Size = Record.size();
685      std::vector<Constant*> Elts;
686
687      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
688        for (unsigned i = 0; i != Size; ++i)
689          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
690                                                     STy->getElementType(i)));
691        V = ConstantStruct::get(STy, Elts);
692      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
693        const Type *EltTy = ATy->getElementType();
694        for (unsigned i = 0; i != Size; ++i)
695          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
696        V = ConstantArray::get(ATy, Elts);
697      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
698        const Type *EltTy = VTy->getElementType();
699        for (unsigned i = 0; i != Size; ++i)
700          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
701        V = ConstantVector::get(Elts);
702      } else {
703        V = UndefValue::get(CurTy);
704      }
705      break;
706    }
707    case bitc::CST_CODE_STRING: { // STRING: [values]
708      if (Record.empty())
709        return Error("Invalid CST_AGGREGATE record");
710
711      const ArrayType *ATy = cast<ArrayType>(CurTy);
712      const Type *EltTy = ATy->getElementType();
713
714      unsigned Size = Record.size();
715      std::vector<Constant*> Elts;
716      for (unsigned i = 0; i != Size; ++i)
717        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
718      V = ConstantArray::get(ATy, Elts);
719      break;
720    }
721    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
722      if (Record.empty())
723        return Error("Invalid CST_AGGREGATE record");
724
725      const ArrayType *ATy = cast<ArrayType>(CurTy);
726      const Type *EltTy = ATy->getElementType();
727
728      unsigned Size = Record.size();
729      std::vector<Constant*> Elts;
730      for (unsigned i = 0; i != Size; ++i)
731        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
732      Elts.push_back(Constant::getNullValue(EltTy));
733      V = ConstantArray::get(ATy, Elts);
734      break;
735    }
736    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
737      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
738      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
739      if (Opc < 0) {
740        V = UndefValue::get(CurTy);  // Unknown binop.
741      } else {
742        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
743        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
744        V = ConstantExpr::get(Opc, LHS, RHS);
745      }
746      break;
747    }
748    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
749      if (Record.size() < 3) return Error("Invalid CE_CAST record");
750      int Opc = GetDecodedCastOpcode(Record[0]);
751      if (Opc < 0) {
752        V = UndefValue::get(CurTy);  // Unknown cast.
753      } else {
754        const Type *OpTy = getTypeByID(Record[1]);
755        if (!OpTy) return Error("Invalid CE_CAST record");
756        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
757        V = ConstantExpr::getCast(Opc, Op, CurTy);
758      }
759      break;
760    }
761    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
762      if (Record.size() & 1) return Error("Invalid CE_GEP record");
763      SmallVector<Constant*, 16> Elts;
764      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
765        const Type *ElTy = getTypeByID(Record[i]);
766        if (!ElTy) return Error("Invalid CE_GEP record");
767        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
768      }
769      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
770      break;
771    }
772    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
773      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
774      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
775                                                              Type::Int1Ty),
776                                  ValueList.getConstantFwdRef(Record[1],CurTy),
777                                  ValueList.getConstantFwdRef(Record[2],CurTy));
778      break;
779    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
780      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
781      const VectorType *OpTy =
782        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
783      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
784      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
785      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
786                                                  OpTy->getElementType());
787      V = ConstantExpr::getExtractElement(Op0, Op1);
788      break;
789    }
790    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
791      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
792      if (Record.size() < 3 || OpTy == 0)
793        return Error("Invalid CE_INSERTELT record");
794      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
795      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
796                                                  OpTy->getElementType());
797      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
798      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
799      break;
800    }
801    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
802      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
803      if (Record.size() < 3 || OpTy == 0)
804        return Error("Invalid CE_INSERTELT record");
805      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
806      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
807      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
808      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
809      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
810      break;
811    }
812    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
813      if (Record.size() < 4) return Error("Invalid CE_CMP record");
814      const Type *OpTy = getTypeByID(Record[0]);
815      if (OpTy == 0) return Error("Invalid CE_CMP record");
816      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
817      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
818
819      if (OpTy->isFloatingPoint())
820        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
821      else if (!isa<VectorType>(OpTy))
822        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
823      else if (OpTy->isFPOrFPVector())
824        V = ConstantExpr::getVFCmp(Record[3], Op0, Op1);
825      else
826        V = ConstantExpr::getVICmp(Record[3], Op0, Op1);
827      break;
828    }
829    case bitc::CST_CODE_INLINEASM: {
830      if (Record.size() < 2) return Error("Invalid INLINEASM record");
831      std::string AsmStr, ConstrStr;
832      bool HasSideEffects = Record[0];
833      unsigned AsmStrSize = Record[1];
834      if (2+AsmStrSize >= Record.size())
835        return Error("Invalid INLINEASM record");
836      unsigned ConstStrSize = Record[2+AsmStrSize];
837      if (3+AsmStrSize+ConstStrSize > Record.size())
838        return Error("Invalid INLINEASM record");
839
840      for (unsigned i = 0; i != AsmStrSize; ++i)
841        AsmStr += (char)Record[2+i];
842      for (unsigned i = 0; i != ConstStrSize; ++i)
843        ConstrStr += (char)Record[3+AsmStrSize+i];
844      const PointerType *PTy = cast<PointerType>(CurTy);
845      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
846                         AsmStr, ConstrStr, HasSideEffects);
847      break;
848    }
849    }
850
851    ValueList.AssignValue(V, NextCstNo);
852    ++NextCstNo;
853  }
854}
855
856/// RememberAndSkipFunctionBody - When we see the block for a function body,
857/// remember where it is and then skip it.  This lets us lazily deserialize the
858/// functions.
859bool BitcodeReader::RememberAndSkipFunctionBody() {
860  // Get the function we are talking about.
861  if (FunctionsWithBodies.empty())
862    return Error("Insufficient function protos");
863
864  Function *Fn = FunctionsWithBodies.back();
865  FunctionsWithBodies.pop_back();
866
867  // Save the current stream state.
868  uint64_t CurBit = Stream.GetCurrentBitNo();
869  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
870
871  // Set the functions linkage to GhostLinkage so we know it is lazily
872  // deserialized.
873  Fn->setLinkage(GlobalValue::GhostLinkage);
874
875  // Skip over the function block for now.
876  if (Stream.SkipBlock())
877    return Error("Malformed block record");
878  return false;
879}
880
881bool BitcodeReader::ParseModule(const std::string &ModuleID) {
882  // Reject multiple MODULE_BLOCK's in a single bitstream.
883  if (TheModule)
884    return Error("Multiple MODULE_BLOCKs in same stream");
885
886  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
887    return Error("Malformed block record");
888
889  // Otherwise, create the module.
890  TheModule = new Module(ModuleID);
891
892  SmallVector<uint64_t, 64> Record;
893  std::vector<std::string> SectionTable;
894  std::vector<std::string> CollectorTable;
895
896  // Read all the records for this module.
897  while (!Stream.AtEndOfStream()) {
898    unsigned Code = Stream.ReadCode();
899    if (Code == bitc::END_BLOCK) {
900      if (Stream.ReadBlockEnd())
901        return Error("Error at end of module block");
902
903      // Patch the initializers for globals and aliases up.
904      ResolveGlobalAndAliasInits();
905      if (!GlobalInits.empty() || !AliasInits.empty())
906        return Error("Malformed global initializer set");
907      if (!FunctionsWithBodies.empty())
908        return Error("Too few function bodies found");
909
910      // Look for intrinsic functions which need to be upgraded at some point
911      for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
912           FI != FE; ++FI) {
913        Function* NewFn;
914        if (UpgradeIntrinsicFunction(FI, NewFn))
915          UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
916      }
917
918      // Force deallocation of memory for these vectors to favor the client that
919      // want lazy deserialization.
920      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
921      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
922      std::vector<Function*>().swap(FunctionsWithBodies);
923      return false;
924    }
925
926    if (Code == bitc::ENTER_SUBBLOCK) {
927      switch (Stream.ReadSubBlockID()) {
928      default:  // Skip unknown content.
929        if (Stream.SkipBlock())
930          return Error("Malformed block record");
931        break;
932      case bitc::BLOCKINFO_BLOCK_ID:
933        if (Stream.ReadBlockInfoBlock())
934          return Error("Malformed BlockInfoBlock");
935        break;
936      case bitc::PARAMATTR_BLOCK_ID:
937        if (ParseParamAttrBlock())
938          return true;
939        break;
940      case bitc::TYPE_BLOCK_ID:
941        if (ParseTypeTable())
942          return true;
943        break;
944      case bitc::TYPE_SYMTAB_BLOCK_ID:
945        if (ParseTypeSymbolTable())
946          return true;
947        break;
948      case bitc::VALUE_SYMTAB_BLOCK_ID:
949        if (ParseValueSymbolTable())
950          return true;
951        break;
952      case bitc::CONSTANTS_BLOCK_ID:
953        if (ParseConstants() || ResolveGlobalAndAliasInits())
954          return true;
955        break;
956      case bitc::FUNCTION_BLOCK_ID:
957        // If this is the first function body we've seen, reverse the
958        // FunctionsWithBodies list.
959        if (!HasReversedFunctionsWithBodies) {
960          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
961          HasReversedFunctionsWithBodies = true;
962        }
963
964        if (RememberAndSkipFunctionBody())
965          return true;
966        break;
967      }
968      continue;
969    }
970
971    if (Code == bitc::DEFINE_ABBREV) {
972      Stream.ReadAbbrevRecord();
973      continue;
974    }
975
976    // Read a record.
977    switch (Stream.ReadRecord(Code, Record)) {
978    default: break;  // Default behavior, ignore unknown content.
979    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
980      if (Record.size() < 1)
981        return Error("Malformed MODULE_CODE_VERSION");
982      // Only version #0 is supported so far.
983      if (Record[0] != 0)
984        return Error("Unknown bitstream version!");
985      break;
986    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
987      std::string S;
988      if (ConvertToString(Record, 0, S))
989        return Error("Invalid MODULE_CODE_TRIPLE record");
990      TheModule->setTargetTriple(S);
991      break;
992    }
993    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
994      std::string S;
995      if (ConvertToString(Record, 0, S))
996        return Error("Invalid MODULE_CODE_DATALAYOUT record");
997      TheModule->setDataLayout(S);
998      break;
999    }
1000    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
1001      std::string S;
1002      if (ConvertToString(Record, 0, S))
1003        return Error("Invalid MODULE_CODE_ASM record");
1004      TheModule->setModuleInlineAsm(S);
1005      break;
1006    }
1007    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
1008      std::string S;
1009      if (ConvertToString(Record, 0, S))
1010        return Error("Invalid MODULE_CODE_DEPLIB record");
1011      TheModule->addLibrary(S);
1012      break;
1013    }
1014    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
1015      std::string S;
1016      if (ConvertToString(Record, 0, S))
1017        return Error("Invalid MODULE_CODE_SECTIONNAME record");
1018      SectionTable.push_back(S);
1019      break;
1020    }
1021    case bitc::MODULE_CODE_COLLECTORNAME: {  // SECTIONNAME: [strchr x N]
1022      std::string S;
1023      if (ConvertToString(Record, 0, S))
1024        return Error("Invalid MODULE_CODE_COLLECTORNAME record");
1025      CollectorTable.push_back(S);
1026      break;
1027    }
1028    // GLOBALVAR: [pointer type, isconst, initid,
1029    //             linkage, alignment, section, visibility, threadlocal]
1030    case bitc::MODULE_CODE_GLOBALVAR: {
1031      if (Record.size() < 6)
1032        return Error("Invalid MODULE_CODE_GLOBALVAR record");
1033      const Type *Ty = getTypeByID(Record[0]);
1034      if (!isa<PointerType>(Ty))
1035        return Error("Global not a pointer type!");
1036      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
1037      Ty = cast<PointerType>(Ty)->getElementType();
1038
1039      bool isConstant = Record[1];
1040      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1041      unsigned Alignment = (1 << Record[4]) >> 1;
1042      std::string Section;
1043      if (Record[5]) {
1044        if (Record[5]-1 >= SectionTable.size())
1045          return Error("Invalid section ID");
1046        Section = SectionTable[Record[5]-1];
1047      }
1048      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1049      if (Record.size() > 6)
1050        Visibility = GetDecodedVisibility(Record[6]);
1051      bool isThreadLocal = false;
1052      if (Record.size() > 7)
1053        isThreadLocal = Record[7];
1054
1055      GlobalVariable *NewGV =
1056        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule,
1057                           isThreadLocal, AddressSpace);
1058      NewGV->setAlignment(Alignment);
1059      if (!Section.empty())
1060        NewGV->setSection(Section);
1061      NewGV->setVisibility(Visibility);
1062      NewGV->setThreadLocal(isThreadLocal);
1063
1064      ValueList.push_back(NewGV);
1065
1066      // Remember which value to use for the global initializer.
1067      if (unsigned InitID = Record[2])
1068        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1069      break;
1070    }
1071    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1072    //             alignment, section, visibility, collector]
1073    case bitc::MODULE_CODE_FUNCTION: {
1074      if (Record.size() < 8)
1075        return Error("Invalid MODULE_CODE_FUNCTION record");
1076      const Type *Ty = getTypeByID(Record[0]);
1077      if (!isa<PointerType>(Ty))
1078        return Error("Function not a pointer type!");
1079      const FunctionType *FTy =
1080        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1081      if (!FTy)
1082        return Error("Function not a pointer to function type!");
1083
1084      Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
1085                                        "", TheModule);
1086
1087      Func->setCallingConv(Record[1]);
1088      bool isProto = Record[2];
1089      Func->setLinkage(GetDecodedLinkage(Record[3]));
1090      Func->setParamAttrs(getParamAttrs(Record[4]));
1091
1092      Func->setAlignment((1 << Record[5]) >> 1);
1093      if (Record[6]) {
1094        if (Record[6]-1 >= SectionTable.size())
1095          return Error("Invalid section ID");
1096        Func->setSection(SectionTable[Record[6]-1]);
1097      }
1098      Func->setVisibility(GetDecodedVisibility(Record[7]));
1099      if (Record.size() > 8 && Record[8]) {
1100        if (Record[8]-1 > CollectorTable.size())
1101          return Error("Invalid collector ID");
1102        Func->setCollector(CollectorTable[Record[8]-1].c_str());
1103      }
1104
1105      ValueList.push_back(Func);
1106
1107      // If this is a function with a body, remember the prototype we are
1108      // creating now, so that we can match up the body with them later.
1109      if (!isProto)
1110        FunctionsWithBodies.push_back(Func);
1111      break;
1112    }
1113    // ALIAS: [alias type, aliasee val#, linkage]
1114    // ALIAS: [alias type, aliasee val#, linkage, visibility]
1115    case bitc::MODULE_CODE_ALIAS: {
1116      if (Record.size() < 3)
1117        return Error("Invalid MODULE_ALIAS record");
1118      const Type *Ty = getTypeByID(Record[0]);
1119      if (!isa<PointerType>(Ty))
1120        return Error("Function not a pointer type!");
1121
1122      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1123                                           "", 0, TheModule);
1124      // Old bitcode files didn't have visibility field.
1125      if (Record.size() > 3)
1126        NewGA->setVisibility(GetDecodedVisibility(Record[3]));
1127      ValueList.push_back(NewGA);
1128      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1129      break;
1130    }
1131    /// MODULE_CODE_PURGEVALS: [numvals]
1132    case bitc::MODULE_CODE_PURGEVALS:
1133      // Trim down the value list to the specified size.
1134      if (Record.size() < 1 || Record[0] > ValueList.size())
1135        return Error("Invalid MODULE_PURGEVALS record");
1136      ValueList.shrinkTo(Record[0]);
1137      break;
1138    }
1139    Record.clear();
1140  }
1141
1142  return Error("Premature end of bitstream");
1143}
1144
1145
1146bool BitcodeReader::ParseBitcode() {
1147  TheModule = 0;
1148
1149  if (Buffer->getBufferSize() & 3)
1150    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1151
1152  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1153  Stream.init(BufPtr, BufPtr+Buffer->getBufferSize());
1154
1155  // Sniff for the signature.
1156  if (Stream.Read(8) != 'B' ||
1157      Stream.Read(8) != 'C' ||
1158      Stream.Read(4) != 0x0 ||
1159      Stream.Read(4) != 0xC ||
1160      Stream.Read(4) != 0xE ||
1161      Stream.Read(4) != 0xD)
1162    return Error("Invalid bitcode signature");
1163
1164  // We expect a number of well-defined blocks, though we don't necessarily
1165  // need to understand them all.
1166  while (!Stream.AtEndOfStream()) {
1167    unsigned Code = Stream.ReadCode();
1168
1169    if (Code != bitc::ENTER_SUBBLOCK)
1170      return Error("Invalid record at top-level");
1171
1172    unsigned BlockID = Stream.ReadSubBlockID();
1173
1174    // We only know the MODULE subblock ID.
1175    switch (BlockID) {
1176    case bitc::BLOCKINFO_BLOCK_ID:
1177      if (Stream.ReadBlockInfoBlock())
1178        return Error("Malformed BlockInfoBlock");
1179      break;
1180    case bitc::MODULE_BLOCK_ID:
1181      if (ParseModule(Buffer->getBufferIdentifier()))
1182        return true;
1183      break;
1184    default:
1185      if (Stream.SkipBlock())
1186        return Error("Malformed block record");
1187      break;
1188    }
1189  }
1190
1191  return false;
1192}
1193
1194
1195/// ParseFunctionBody - Lazily parse the specified function body block.
1196bool BitcodeReader::ParseFunctionBody(Function *F) {
1197  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1198    return Error("Malformed block record");
1199
1200  unsigned ModuleValueListSize = ValueList.size();
1201
1202  // Add all the function arguments to the value table.
1203  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1204    ValueList.push_back(I);
1205
1206  unsigned NextValueNo = ValueList.size();
1207  BasicBlock *CurBB = 0;
1208  unsigned CurBBNo = 0;
1209
1210  // Read all the records.
1211  SmallVector<uint64_t, 64> Record;
1212  while (1) {
1213    unsigned Code = Stream.ReadCode();
1214    if (Code == bitc::END_BLOCK) {
1215      if (Stream.ReadBlockEnd())
1216        return Error("Error at end of function block");
1217      break;
1218    }
1219
1220    if (Code == bitc::ENTER_SUBBLOCK) {
1221      switch (Stream.ReadSubBlockID()) {
1222      default:  // Skip unknown content.
1223        if (Stream.SkipBlock())
1224          return Error("Malformed block record");
1225        break;
1226      case bitc::CONSTANTS_BLOCK_ID:
1227        if (ParseConstants()) return true;
1228        NextValueNo = ValueList.size();
1229        break;
1230      case bitc::VALUE_SYMTAB_BLOCK_ID:
1231        if (ParseValueSymbolTable()) return true;
1232        break;
1233      }
1234      continue;
1235    }
1236
1237    if (Code == bitc::DEFINE_ABBREV) {
1238      Stream.ReadAbbrevRecord();
1239      continue;
1240    }
1241
1242    // Read a record.
1243    Record.clear();
1244    Instruction *I = 0;
1245    switch (Stream.ReadRecord(Code, Record)) {
1246    default: // Default behavior: reject
1247      return Error("Unknown instruction");
1248    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1249      if (Record.size() < 1 || Record[0] == 0)
1250        return Error("Invalid DECLAREBLOCKS record");
1251      // Create all the basic blocks for the function.
1252      FunctionBBs.resize(Record[0]);
1253      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1254        FunctionBBs[i] = BasicBlock::Create("", F);
1255      CurBB = FunctionBBs[0];
1256      continue;
1257
1258    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1259      unsigned OpNum = 0;
1260      Value *LHS, *RHS;
1261      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1262          getValue(Record, OpNum, LHS->getType(), RHS) ||
1263          OpNum+1 != Record.size())
1264        return Error("Invalid BINOP record");
1265
1266      int Opc = GetDecodedBinaryOpcode(Record[OpNum], LHS->getType());
1267      if (Opc == -1) return Error("Invalid BINOP record");
1268      I = BinaryOperator::create((Instruction::BinaryOps)Opc, LHS, RHS);
1269      break;
1270    }
1271    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
1272      unsigned OpNum = 0;
1273      Value *Op;
1274      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1275          OpNum+2 != Record.size())
1276        return Error("Invalid CAST record");
1277
1278      const Type *ResTy = getTypeByID(Record[OpNum]);
1279      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
1280      if (Opc == -1 || ResTy == 0)
1281        return Error("Invalid CAST record");
1282      I = CastInst::create((Instruction::CastOps)Opc, Op, ResTy);
1283      break;
1284    }
1285    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
1286      unsigned OpNum = 0;
1287      Value *BasePtr;
1288      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
1289        return Error("Invalid GEP record");
1290
1291      SmallVector<Value*, 16> GEPIdx;
1292      while (OpNum != Record.size()) {
1293        Value *Op;
1294        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1295          return Error("Invalid GEP record");
1296        GEPIdx.push_back(Op);
1297      }
1298
1299      I = GetElementPtrInst::Create(BasePtr, GEPIdx.begin(), GEPIdx.end());
1300      break;
1301    }
1302
1303    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
1304      unsigned OpNum = 0;
1305      Value *TrueVal, *FalseVal, *Cond;
1306      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
1307          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
1308          getValue(Record, OpNum, Type::Int1Ty, Cond))
1309        return Error("Invalid SELECT record");
1310
1311      I = SelectInst::Create(Cond, TrueVal, FalseVal);
1312      break;
1313    }
1314
1315    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1316      unsigned OpNum = 0;
1317      Value *Vec, *Idx;
1318      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1319          getValue(Record, OpNum, Type::Int32Ty, Idx))
1320        return Error("Invalid EXTRACTELT record");
1321      I = new ExtractElementInst(Vec, Idx);
1322      break;
1323    }
1324
1325    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1326      unsigned OpNum = 0;
1327      Value *Vec, *Elt, *Idx;
1328      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1329          getValue(Record, OpNum,
1330                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
1331          getValue(Record, OpNum, Type::Int32Ty, Idx))
1332        return Error("Invalid INSERTELT record");
1333      I = InsertElementInst::Create(Vec, Elt, Idx);
1334      break;
1335    }
1336
1337    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
1338      unsigned OpNum = 0;
1339      Value *Vec1, *Vec2, *Mask;
1340      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
1341          getValue(Record, OpNum, Vec1->getType(), Vec2))
1342        return Error("Invalid SHUFFLEVEC record");
1343
1344      const Type *MaskTy =
1345        VectorType::get(Type::Int32Ty,
1346                        cast<VectorType>(Vec1->getType())->getNumElements());
1347
1348      if (getValue(Record, OpNum, MaskTy, Mask))
1349        return Error("Invalid SHUFFLEVEC record");
1350      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1351      break;
1352    }
1353
1354    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1355      unsigned OpNum = 0;
1356      Value *LHS, *RHS;
1357      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1358          getValue(Record, OpNum, LHS->getType(), RHS) ||
1359          OpNum+1 != Record.size())
1360        return Error("Invalid CMP record");
1361
1362      if (LHS->getType()->isFloatingPoint())
1363        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1364      else if (!isa<VectorType>(LHS->getType()))
1365        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1366      else if (LHS->getType()->isFPOrFPVector())
1367        I = new VFCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1368      else
1369        I = new VICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1370      break;
1371    }
1372    case bitc::FUNC_CODE_INST_GETRESULT: { // GETRESULT: [ty, val, n]
1373      if (Record.size() != 2)
1374        return Error("Invalid GETRESULT record");
1375      unsigned OpNum = 0;
1376      Value *Op;
1377      getValueTypePair(Record, OpNum, NextValueNo, Op);
1378      unsigned Index = Record[1];
1379      I = new GetResultInst(Op, Index);
1380      break;
1381    }
1382
1383    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1384      {
1385        unsigned Size = Record.size();
1386        if (Size == 0) {
1387          I = ReturnInst::Create();
1388          break;
1389        } else {
1390          unsigned OpNum = 0;
1391          SmallVector<Value *,4> Vs;
1392          do {
1393            Value *Op = NULL;
1394            if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1395              return Error("Invalid RET record");
1396            Vs.push_back(Op);
1397          } while(OpNum != Record.size());
1398
1399          // SmallVector Vs has at least one element.
1400          I = ReturnInst::Create(&Vs[0], Vs.size());
1401          break;
1402        }
1403      }
1404    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1405      if (Record.size() != 1 && Record.size() != 3)
1406        return Error("Invalid BR record");
1407      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1408      if (TrueDest == 0)
1409        return Error("Invalid BR record");
1410
1411      if (Record.size() == 1)
1412        I = BranchInst::Create(TrueDest);
1413      else {
1414        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1415        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1416        if (FalseDest == 0 || Cond == 0)
1417          return Error("Invalid BR record");
1418        I = BranchInst::Create(TrueDest, FalseDest, Cond);
1419      }
1420      break;
1421    }
1422    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1423      if (Record.size() < 3 || (Record.size() & 1) == 0)
1424        return Error("Invalid SWITCH record");
1425      const Type *OpTy = getTypeByID(Record[0]);
1426      Value *Cond = getFnValueByID(Record[1], OpTy);
1427      BasicBlock *Default = getBasicBlock(Record[2]);
1428      if (OpTy == 0 || Cond == 0 || Default == 0)
1429        return Error("Invalid SWITCH record");
1430      unsigned NumCases = (Record.size()-3)/2;
1431      SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
1432      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1433        ConstantInt *CaseVal =
1434          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1435        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1436        if (CaseVal == 0 || DestBB == 0) {
1437          delete SI;
1438          return Error("Invalid SWITCH record!");
1439        }
1440        SI->addCase(CaseVal, DestBB);
1441      }
1442      I = SI;
1443      break;
1444    }
1445
1446    case bitc::FUNC_CODE_INST_INVOKE: {
1447      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
1448      if (Record.size() < 4) return Error("Invalid INVOKE record");
1449      PAListPtr PAL = getParamAttrs(Record[0]);
1450      unsigned CCInfo = Record[1];
1451      BasicBlock *NormalBB = getBasicBlock(Record[2]);
1452      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
1453
1454      unsigned OpNum = 4;
1455      Value *Callee;
1456      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1457        return Error("Invalid INVOKE record");
1458
1459      const PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
1460      const FunctionType *FTy = !CalleeTy ? 0 :
1461        dyn_cast<FunctionType>(CalleeTy->getElementType());
1462
1463      // Check that the right number of fixed parameters are here.
1464      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
1465          Record.size() < OpNum+FTy->getNumParams())
1466        return Error("Invalid INVOKE record");
1467
1468      SmallVector<Value*, 16> Ops;
1469      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1470        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1471        if (Ops.back() == 0) return Error("Invalid INVOKE record");
1472      }
1473
1474      if (!FTy->isVarArg()) {
1475        if (Record.size() != OpNum)
1476          return Error("Invalid INVOKE record");
1477      } else {
1478        // Read type/value pairs for varargs params.
1479        while (OpNum != Record.size()) {
1480          Value *Op;
1481          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1482            return Error("Invalid INVOKE record");
1483          Ops.push_back(Op);
1484        }
1485      }
1486
1487      I = InvokeInst::Create(Callee, NormalBB, UnwindBB, Ops.begin(), Ops.end());
1488      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1489      cast<InvokeInst>(I)->setParamAttrs(PAL);
1490      break;
1491    }
1492    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1493      I = new UnwindInst();
1494      break;
1495    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1496      I = new UnreachableInst();
1497      break;
1498    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
1499      if (Record.size() < 1 || ((Record.size()-1)&1))
1500        return Error("Invalid PHI record");
1501      const Type *Ty = getTypeByID(Record[0]);
1502      if (!Ty) return Error("Invalid PHI record");
1503
1504      PHINode *PN = PHINode::Create(Ty);
1505      PN->reserveOperandSpace((Record.size()-1)/2);
1506
1507      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
1508        Value *V = getFnValueByID(Record[1+i], Ty);
1509        BasicBlock *BB = getBasicBlock(Record[2+i]);
1510        if (!V || !BB) return Error("Invalid PHI record");
1511        PN->addIncoming(V, BB);
1512      }
1513      I = PN;
1514      break;
1515    }
1516
1517    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1518      if (Record.size() < 3)
1519        return Error("Invalid MALLOC record");
1520      const PointerType *Ty =
1521        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1522      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1523      unsigned Align = Record[2];
1524      if (!Ty || !Size) return Error("Invalid MALLOC record");
1525      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1526      break;
1527    }
1528    case bitc::FUNC_CODE_INST_FREE: { // FREE: [op, opty]
1529      unsigned OpNum = 0;
1530      Value *Op;
1531      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1532          OpNum != Record.size())
1533        return Error("Invalid FREE record");
1534      I = new FreeInst(Op);
1535      break;
1536    }
1537    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1538      if (Record.size() < 3)
1539        return Error("Invalid ALLOCA record");
1540      const PointerType *Ty =
1541        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1542      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1543      unsigned Align = Record[2];
1544      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1545      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1546      break;
1547    }
1548    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1549      unsigned OpNum = 0;
1550      Value *Op;
1551      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1552          OpNum+2 != Record.size())
1553        return Error("Invalid LOAD record");
1554
1555      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1556      break;
1557    }
1558    case bitc::FUNC_CODE_INST_STORE2: { // STORE2:[ptrty, ptr, val, align, vol]
1559      unsigned OpNum = 0;
1560      Value *Val, *Ptr;
1561      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
1562          getValue(Record, OpNum,
1563                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
1564          OpNum+2 != Record.size())
1565        return Error("Invalid STORE record");
1566
1567      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1568      break;
1569    }
1570    case bitc::FUNC_CODE_INST_STORE: { // STORE:[val, valty, ptr, align, vol]
1571      // FIXME: Legacy form of store instruction. Should be removed in LLVM 3.0.
1572      unsigned OpNum = 0;
1573      Value *Val, *Ptr;
1574      if (getValueTypePair(Record, OpNum, NextValueNo, Val) ||
1575          getValue(Record, OpNum, PointerType::getUnqual(Val->getType()), Ptr)||
1576          OpNum+2 != Record.size())
1577        return Error("Invalid STORE record");
1578
1579      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1580      break;
1581    }
1582    case bitc::FUNC_CODE_INST_CALL: {
1583      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
1584      if (Record.size() < 3)
1585        return Error("Invalid CALL record");
1586
1587      PAListPtr PAL = getParamAttrs(Record[0]);
1588      unsigned CCInfo = Record[1];
1589
1590      unsigned OpNum = 2;
1591      Value *Callee;
1592      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1593        return Error("Invalid CALL record");
1594
1595      const PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
1596      const FunctionType *FTy = 0;
1597      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1598      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
1599        return Error("Invalid CALL record");
1600
1601      SmallVector<Value*, 16> Args;
1602      // Read the fixed params.
1603      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1604        if (FTy->getParamType(i)->getTypeID()==Type::LabelTyID)
1605          Args.push_back(getBasicBlock(Record[OpNum]));
1606        else
1607          Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1608        if (Args.back() == 0) return Error("Invalid CALL record");
1609      }
1610
1611      // Read type/value pairs for varargs params.
1612      if (!FTy->isVarArg()) {
1613        if (OpNum != Record.size())
1614          return Error("Invalid CALL record");
1615      } else {
1616        while (OpNum != Record.size()) {
1617          Value *Op;
1618          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1619            return Error("Invalid CALL record");
1620          Args.push_back(Op);
1621        }
1622      }
1623
1624      I = CallInst::Create(Callee, Args.begin(), Args.end());
1625      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1626      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1627      cast<CallInst>(I)->setParamAttrs(PAL);
1628      break;
1629    }
1630    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1631      if (Record.size() < 3)
1632        return Error("Invalid VAARG record");
1633      const Type *OpTy = getTypeByID(Record[0]);
1634      Value *Op = getFnValueByID(Record[1], OpTy);
1635      const Type *ResTy = getTypeByID(Record[2]);
1636      if (!OpTy || !Op || !ResTy)
1637        return Error("Invalid VAARG record");
1638      I = new VAArgInst(Op, ResTy);
1639      break;
1640    }
1641    }
1642
1643    // Add instruction to end of current BB.  If there is no current BB, reject
1644    // this file.
1645    if (CurBB == 0) {
1646      delete I;
1647      return Error("Invalid instruction with no BB");
1648    }
1649    CurBB->getInstList().push_back(I);
1650
1651    // If this was a terminator instruction, move to the next block.
1652    if (isa<TerminatorInst>(I)) {
1653      ++CurBBNo;
1654      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1655    }
1656
1657    // Non-void values get registered in the value table for future use.
1658    if (I && I->getType() != Type::VoidTy)
1659      ValueList.AssignValue(I, NextValueNo++);
1660  }
1661
1662  // Check the function list for unresolved values.
1663  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1664    if (A->getParent() == 0) {
1665      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1666      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1667        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1668          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1669          delete A;
1670        }
1671      }
1672      return Error("Never resolved value found in function!");
1673    }
1674  }
1675
1676  // Trim the value list down to the size it was before we parsed this function.
1677  ValueList.shrinkTo(ModuleValueListSize);
1678  std::vector<BasicBlock*>().swap(FunctionBBs);
1679
1680  return false;
1681}
1682
1683//===----------------------------------------------------------------------===//
1684// ModuleProvider implementation
1685//===----------------------------------------------------------------------===//
1686
1687
1688bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1689  // If it already is material, ignore the request.
1690  if (!F->hasNotBeenReadFromBitcode()) return false;
1691
1692  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1693    DeferredFunctionInfo.find(F);
1694  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1695
1696  // Move the bit stream to the saved position of the deferred function body and
1697  // restore the real linkage type for the function.
1698  Stream.JumpToBit(DFII->second.first);
1699  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1700
1701  if (ParseFunctionBody(F)) {
1702    if (ErrInfo) *ErrInfo = ErrorString;
1703    return true;
1704  }
1705
1706  // Upgrade any old intrinsic calls in the function.
1707  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
1708       E = UpgradedIntrinsics.end(); I != E; ++I) {
1709    if (I->first != I->second) {
1710      for (Value::use_iterator UI = I->first->use_begin(),
1711           UE = I->first->use_end(); UI != UE; ) {
1712        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1713          UpgradeIntrinsicCall(CI, I->second);
1714      }
1715    }
1716  }
1717
1718  return false;
1719}
1720
1721void BitcodeReader::dematerializeFunction(Function *F) {
1722  // If this function isn't materialized, or if it is a proto, this is a noop.
1723  if (F->hasNotBeenReadFromBitcode() || F->isDeclaration())
1724    return;
1725
1726  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
1727
1728  // Just forget the function body, we can remat it later.
1729  F->deleteBody();
1730  F->setLinkage(GlobalValue::GhostLinkage);
1731}
1732
1733
1734Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
1735  for (DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1736       DeferredFunctionInfo.begin(), E = DeferredFunctionInfo.end(); I != E;
1737       ++I) {
1738    Function *F = I->first;
1739    if (F->hasNotBeenReadFromBitcode() &&
1740        materializeFunction(F, ErrInfo))
1741      return 0;
1742  }
1743
1744  // Upgrade any intrinsic calls that slipped through (should not happen!) and
1745  // delete the old functions to clean up. We can't do this unless the entire
1746  // module is materialized because there could always be another function body
1747  // with calls to the old function.
1748  for (std::vector<std::pair<Function*, Function*> >::iterator I =
1749       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
1750    if (I->first != I->second) {
1751      for (Value::use_iterator UI = I->first->use_begin(),
1752           UE = I->first->use_end(); UI != UE; ) {
1753        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1754          UpgradeIntrinsicCall(CI, I->second);
1755      }
1756      ValueList.replaceUsesOfWith(I->first, I->second);
1757      I->first->eraseFromParent();
1758    }
1759  }
1760  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
1761
1762  return TheModule;
1763}
1764
1765
1766/// This method is provided by the parent ModuleProvde class and overriden
1767/// here. It simply releases the module from its provided and frees up our
1768/// state.
1769/// @brief Release our hold on the generated module
1770Module *BitcodeReader::releaseModule(std::string *ErrInfo) {
1771  // Since we're losing control of this Module, we must hand it back complete
1772  Module *M = ModuleProvider::releaseModule(ErrInfo);
1773  FreeState();
1774  return M;
1775}
1776
1777
1778//===----------------------------------------------------------------------===//
1779// External interface
1780//===----------------------------------------------------------------------===//
1781
1782/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1783///
1784ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1785                                               std::string *ErrMsg) {
1786  BitcodeReader *R = new BitcodeReader(Buffer);
1787  if (R->ParseBitcode()) {
1788    if (ErrMsg)
1789      *ErrMsg = R->getErrorString();
1790
1791    // Don't let the BitcodeReader dtor delete 'Buffer'.
1792    R->releaseMemoryBuffer();
1793    delete R;
1794    return 0;
1795  }
1796  return R;
1797}
1798
1799/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
1800/// If an error occurs, return null and fill in *ErrMsg if non-null.
1801Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
1802  BitcodeReader *R;
1803  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
1804  if (!R) return 0;
1805
1806  // Read in the entire module.
1807  Module *M = R->materializeModule(ErrMsg);
1808
1809  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
1810  // there was an error.
1811  R->releaseMemoryBuffer();
1812
1813  // If there was no error, tell ModuleProvider not to delete it when its dtor
1814  // is run.
1815  if (M)
1816    M = R->releaseModule(ErrMsg);
1817
1818  delete R;
1819  return M;
1820}
1821