BitcodeReader.cpp revision 43ad6b3e0d6ada51e9b23aab3e061187f1f5710c 
1//===- BitcodeReader.cpp - Internal BitcodeReader implementation ----------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by Chris Lattner and is distributed under
6// the University of Illinois Open Source 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/ParameterAttributes.h"
22#include "llvm/AutoUpgrade.h"
23#include "llvm/ADT/SmallString.h"
24#include "llvm/Support/MathExtras.h"
25#include "llvm/Support/MemoryBuffer.h"
26using namespace llvm;
27
28void BitcodeReader::FreeState() {
29  delete Buffer;
30  Buffer = 0;
31  std::vector<PATypeHolder>().swap(TypeList);
32  ValueList.clear();
33  std::vector<const ParamAttrsList*>().swap(ParamAttrs);
34  std::vector<BasicBlock*>().swap(FunctionBBs);
35  std::vector<Function*>().swap(FunctionsWithBodies);
36  DeferredFunctionInfo.clear();
37}
38
39//===----------------------------------------------------------------------===//
40//  Helper functions to implement forward reference resolution, etc.
41//===----------------------------------------------------------------------===//
42
43/// ConvertToString - Convert a string from a record into an std::string, return
44/// true on failure.
45template<typename StrTy>
46static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
47                            StrTy &Result) {
48  if (Idx > Record.size())
49    return true;
50
51  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
52    Result += (char)Record[i];
53  return false;
54}
55
56static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
57  switch (Val) {
58  default: // Map unknown/new linkages to external
59  case 0: return GlobalValue::ExternalLinkage;
60  case 1: return GlobalValue::WeakLinkage;
61  case 2: return GlobalValue::AppendingLinkage;
62  case 3: return GlobalValue::InternalLinkage;
63  case 4: return GlobalValue::LinkOnceLinkage;
64  case 5: return GlobalValue::DLLImportLinkage;
65  case 6: return GlobalValue::DLLExportLinkage;
66  case 7: return GlobalValue::ExternalWeakLinkage;
67  }
68}
69
70static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
71  switch (Val) {
72  default: // Map unknown visibilities to default.
73  case 0: return GlobalValue::DefaultVisibility;
74  case 1: return GlobalValue::HiddenVisibility;
75  case 2: return GlobalValue::ProtectedVisibility;
76  }
77}
78
79static int GetDecodedCastOpcode(unsigned Val) {
80  switch (Val) {
81  default: return -1;
82  case bitc::CAST_TRUNC   : return Instruction::Trunc;
83  case bitc::CAST_ZEXT    : return Instruction::ZExt;
84  case bitc::CAST_SEXT    : return Instruction::SExt;
85  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
86  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
87  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
88  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
89  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
90  case bitc::CAST_FPEXT   : return Instruction::FPExt;
91  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
92  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
93  case bitc::CAST_BITCAST : return Instruction::BitCast;
94  }
95}
96static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
97  switch (Val) {
98  default: return -1;
99  case bitc::BINOP_ADD:  return Instruction::Add;
100  case bitc::BINOP_SUB:  return Instruction::Sub;
101  case bitc::BINOP_MUL:  return Instruction::Mul;
102  case bitc::BINOP_UDIV: return Instruction::UDiv;
103  case bitc::BINOP_SDIV:
104    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
105  case bitc::BINOP_UREM: return Instruction::URem;
106  case bitc::BINOP_SREM:
107    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
108  case bitc::BINOP_SHL:  return Instruction::Shl;
109  case bitc::BINOP_LSHR: return Instruction::LShr;
110  case bitc::BINOP_ASHR: return Instruction::AShr;
111  case bitc::BINOP_AND:  return Instruction::And;
112  case bitc::BINOP_OR:   return Instruction::Or;
113  case bitc::BINOP_XOR:  return Instruction::Xor;
114  }
115}
116
117
118namespace {
119  /// @brief A class for maintaining the slot number definition
120  /// as a placeholder for the actual definition for forward constants defs.
121  class ConstantPlaceHolder : public ConstantExpr {
122    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
123    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
124  public:
125    Use Op;
126    explicit ConstantPlaceHolder(const Type *Ty)
127      : ConstantExpr(Ty, Instruction::UserOp1, &Op, 1),
128        Op(UndefValue::get(Type::Int32Ty), this) {
129    }
130  };
131}
132
133Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
134                                                    const Type *Ty) {
135  if (Idx >= size()) {
136    // Insert a bunch of null values.
137    Uses.resize(Idx+1);
138    OperandList = &Uses[0];
139    NumOperands = Idx+1;
140  }
141
142  if (Value *V = Uses[Idx]) {
143    assert(Ty == V->getType() && "Type mismatch in constant table!");
144    return cast<Constant>(V);
145  }
146
147  // Create and return a placeholder, which will later be RAUW'd.
148  Constant *C = new ConstantPlaceHolder(Ty);
149  Uses[Idx].init(C, this);
150  return C;
151}
152
153Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
154  if (Idx >= size()) {
155    // Insert a bunch of null values.
156    Uses.resize(Idx+1);
157    OperandList = &Uses[0];
158    NumOperands = Idx+1;
159  }
160
161  if (Value *V = Uses[Idx]) {
162    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
163    return V;
164  }
165
166  // No type specified, must be invalid reference.
167  if (Ty == 0) return 0;
168
169  // Create and return a placeholder, which will later be RAUW'd.
170  Value *V = new Argument(Ty);
171  Uses[Idx].init(V, this);
172  return V;
173}
174
175
176const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
177  // If the TypeID is in range, return it.
178  if (ID < TypeList.size())
179    return TypeList[ID].get();
180  if (!isTypeTable) return 0;
181
182  // The type table allows forward references.  Push as many Opaque types as
183  // needed to get up to ID.
184  while (TypeList.size() <= ID)
185    TypeList.push_back(OpaqueType::get());
186  return TypeList.back().get();
187}
188
189//===----------------------------------------------------------------------===//
190//  Functions for parsing blocks from the bitcode file
191//===----------------------------------------------------------------------===//
192
193bool BitcodeReader::ParseParamAttrBlock() {
194  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
195    return Error("Malformed block record");
196
197  if (!ParamAttrs.empty())
198    return Error("Multiple PARAMATTR blocks found!");
199
200  SmallVector<uint64_t, 64> Record;
201
202  ParamAttrsVector Attrs;
203
204  // Read all the records.
205  while (1) {
206    unsigned Code = Stream.ReadCode();
207    if (Code == bitc::END_BLOCK) {
208      if (Stream.ReadBlockEnd())
209        return Error("Error at end of PARAMATTR block");
210      return false;
211    }
212
213    if (Code == bitc::ENTER_SUBBLOCK) {
214      // No known subblocks, always skip them.
215      Stream.ReadSubBlockID();
216      if (Stream.SkipBlock())
217        return Error("Malformed block record");
218      continue;
219    }
220
221    if (Code == bitc::DEFINE_ABBREV) {
222      Stream.ReadAbbrevRecord();
223      continue;
224    }
225
226    // Read a record.
227    Record.clear();
228    switch (Stream.ReadRecord(Code, Record)) {
229    default:  // Default behavior: ignore.
230      break;
231    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
232      if (Record.size() & 1)
233        return Error("Invalid ENTRY record");
234
235      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
236        if (Record[i+1] != ParamAttr::None)
237          Attrs.push_back(ParamAttrsWithIndex::get(Record[i], Record[i+1]));
238      }
239      ParamAttrs.push_back(Attrs.empty() ? NULL : ParamAttrsList::get(Attrs));
240      Attrs.clear();
241      break;
242    }
243    }
244  }
245}
246
247
248bool BitcodeReader::ParseTypeTable() {
249  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID))
250    return Error("Malformed block record");
251
252  if (!TypeList.empty())
253    return Error("Multiple TYPE_BLOCKs found!");
254
255  SmallVector<uint64_t, 64> Record;
256  unsigned NumRecords = 0;
257
258  // Read all the records for this type table.
259  while (1) {
260    unsigned Code = Stream.ReadCode();
261    if (Code == bitc::END_BLOCK) {
262      if (NumRecords != TypeList.size())
263        return Error("Invalid type forward reference in TYPE_BLOCK");
264      if (Stream.ReadBlockEnd())
265        return Error("Error at end of type table block");
266      return false;
267    }
268
269    if (Code == bitc::ENTER_SUBBLOCK) {
270      // No known subblocks, always skip them.
271      Stream.ReadSubBlockID();
272      if (Stream.SkipBlock())
273        return Error("Malformed block record");
274      continue;
275    }
276
277    if (Code == bitc::DEFINE_ABBREV) {
278      Stream.ReadAbbrevRecord();
279      continue;
280    }
281
282    // Read a record.
283    Record.clear();
284    const Type *ResultTy = 0;
285    switch (Stream.ReadRecord(Code, Record)) {
286    default:  // Default behavior: unknown type.
287      ResultTy = 0;
288      break;
289    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
290      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
291      // type list.  This allows us to reserve space.
292      if (Record.size() < 1)
293        return Error("Invalid TYPE_CODE_NUMENTRY record");
294      TypeList.reserve(Record[0]);
295      continue;
296    case bitc::TYPE_CODE_VOID:      // VOID
297      ResultTy = Type::VoidTy;
298      break;
299    case bitc::TYPE_CODE_FLOAT:     // FLOAT
300      ResultTy = Type::FloatTy;
301      break;
302    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
303      ResultTy = Type::DoubleTy;
304      break;
305    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
306      ResultTy = Type::X86_FP80Ty;
307      break;
308    case bitc::TYPE_CODE_FP128:     // FP128
309      ResultTy = Type::FP128Ty;
310      break;
311    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
312      ResultTy = Type::PPC_FP128Ty;
313      break;
314    case bitc::TYPE_CODE_LABEL:     // LABEL
315      ResultTy = Type::LabelTy;
316      break;
317    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
318      ResultTy = 0;
319      break;
320    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
321      if (Record.size() < 1)
322        return Error("Invalid Integer type record");
323
324      ResultTy = IntegerType::get(Record[0]);
325      break;
326    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
327                                    //          [pointee type, address space]
328      if (Record.size() < 1)
329        return Error("Invalid POINTER type record");
330      unsigned AddressSpace = 0;
331      if (Record.size() == 2)
332        AddressSpace = Record[1];
333      ResultTy = PointerType::get(getTypeByID(Record[0], true), AddressSpace);
334      break;
335    }
336    case bitc::TYPE_CODE_FUNCTION: {
337      // FIXME: attrid is dead, remove it in LLVM 3.0
338      // FUNCTION: [vararg, attrid, retty, paramty x N]
339      if (Record.size() < 3)
340        return Error("Invalid FUNCTION type record");
341      std::vector<const Type*> ArgTys;
342      for (unsigned i = 3, e = Record.size(); i != e; ++i)
343        ArgTys.push_back(getTypeByID(Record[i], true));
344
345      ResultTy = FunctionType::get(getTypeByID(Record[2], true), ArgTys,
346                                   Record[0]);
347      break;
348    }
349    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, eltty x N]
350      if (Record.size() < 1)
351        return Error("Invalid STRUCT type record");
352      std::vector<const Type*> EltTys;
353      for (unsigned i = 1, e = Record.size(); i != e; ++i)
354        EltTys.push_back(getTypeByID(Record[i], true));
355      ResultTy = StructType::get(EltTys, Record[0]);
356      break;
357    }
358    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
359      if (Record.size() < 2)
360        return Error("Invalid ARRAY type record");
361      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
362      break;
363    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
364      if (Record.size() < 2)
365        return Error("Invalid VECTOR type record");
366      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
367      break;
368    }
369
370    if (NumRecords == TypeList.size()) {
371      // If this is a new type slot, just append it.
372      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
373      ++NumRecords;
374    } else if (ResultTy == 0) {
375      // Otherwise, this was forward referenced, so an opaque type was created,
376      // but the result type is actually just an opaque.  Leave the one we
377      // created previously.
378      ++NumRecords;
379    } else {
380      // Otherwise, this was forward referenced, so an opaque type was created.
381      // Resolve the opaque type to the real type now.
382      assert(NumRecords < TypeList.size() && "Typelist imbalance");
383      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
384
385      // Don't directly push the new type on the Tab. Instead we want to replace
386      // the opaque type we previously inserted with the new concrete value. The
387      // refinement from the abstract (opaque) type to the new type causes all
388      // uses of the abstract type to use the concrete type (NewTy). This will
389      // also cause the opaque type to be deleted.
390      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
391
392      // This should have replaced the old opaque type with the new type in the
393      // value table... or with a preexisting type that was already in the
394      // system.  Let's just make sure it did.
395      assert(TypeList[NumRecords-1].get() != OldTy &&
396             "refineAbstractType didn't work!");
397    }
398  }
399}
400
401
402bool BitcodeReader::ParseTypeSymbolTable() {
403  if (Stream.EnterSubBlock(bitc::TYPE_SYMTAB_BLOCK_ID))
404    return Error("Malformed block record");
405
406  SmallVector<uint64_t, 64> Record;
407
408  // Read all the records for this type table.
409  std::string TypeName;
410  while (1) {
411    unsigned Code = Stream.ReadCode();
412    if (Code == bitc::END_BLOCK) {
413      if (Stream.ReadBlockEnd())
414        return Error("Error at end of type symbol table block");
415      return false;
416    }
417
418    if (Code == bitc::ENTER_SUBBLOCK) {
419      // No known subblocks, always skip them.
420      Stream.ReadSubBlockID();
421      if (Stream.SkipBlock())
422        return Error("Malformed block record");
423      continue;
424    }
425
426    if (Code == bitc::DEFINE_ABBREV) {
427      Stream.ReadAbbrevRecord();
428      continue;
429    }
430
431    // Read a record.
432    Record.clear();
433    switch (Stream.ReadRecord(Code, Record)) {
434    default:  // Default behavior: unknown type.
435      break;
436    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namechar x N]
437      if (ConvertToString(Record, 1, TypeName))
438        return Error("Invalid TST_ENTRY record");
439      unsigned TypeID = Record[0];
440      if (TypeID >= TypeList.size())
441        return Error("Invalid Type ID in TST_ENTRY record");
442
443      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
444      TypeName.clear();
445      break;
446    }
447  }
448}
449
450bool BitcodeReader::ParseValueSymbolTable() {
451  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
452    return Error("Malformed block record");
453
454  SmallVector<uint64_t, 64> Record;
455
456  // Read all the records for this value table.
457  SmallString<128> ValueName;
458  while (1) {
459    unsigned Code = Stream.ReadCode();
460    if (Code == bitc::END_BLOCK) {
461      if (Stream.ReadBlockEnd())
462        return Error("Error at end of value symbol table block");
463      return false;
464    }
465    if (Code == bitc::ENTER_SUBBLOCK) {
466      // No known subblocks, always skip them.
467      Stream.ReadSubBlockID();
468      if (Stream.SkipBlock())
469        return Error("Malformed block record");
470      continue;
471    }
472
473    if (Code == bitc::DEFINE_ABBREV) {
474      Stream.ReadAbbrevRecord();
475      continue;
476    }
477
478    // Read a record.
479    Record.clear();
480    switch (Stream.ReadRecord(Code, Record)) {
481    default:  // Default behavior: unknown type.
482      break;
483    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
484      if (ConvertToString(Record, 1, ValueName))
485        return Error("Invalid TST_ENTRY record");
486      unsigned ValueID = Record[0];
487      if (ValueID >= ValueList.size())
488        return Error("Invalid Value ID in VST_ENTRY record");
489      Value *V = ValueList[ValueID];
490
491      V->setName(&ValueName[0], ValueName.size());
492      ValueName.clear();
493      break;
494    }
495    case bitc::VST_CODE_BBENTRY: {
496      if (ConvertToString(Record, 1, ValueName))
497        return Error("Invalid VST_BBENTRY record");
498      BasicBlock *BB = getBasicBlock(Record[0]);
499      if (BB == 0)
500        return Error("Invalid BB ID in VST_BBENTRY record");
501
502      BB->setName(&ValueName[0], ValueName.size());
503      ValueName.clear();
504      break;
505    }
506    }
507  }
508}
509
510/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
511/// the LSB for dense VBR encoding.
512static uint64_t DecodeSignRotatedValue(uint64_t V) {
513  if ((V & 1) == 0)
514    return V >> 1;
515  if (V != 1)
516    return -(V >> 1);
517  // There is no such thing as -0 with integers.  "-0" really means MININT.
518  return 1ULL << 63;
519}
520
521/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
522/// values and aliases that we can.
523bool BitcodeReader::ResolveGlobalAndAliasInits() {
524  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
525  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
526
527  GlobalInitWorklist.swap(GlobalInits);
528  AliasInitWorklist.swap(AliasInits);
529
530  while (!GlobalInitWorklist.empty()) {
531    unsigned ValID = GlobalInitWorklist.back().second;
532    if (ValID >= ValueList.size()) {
533      // Not ready to resolve this yet, it requires something later in the file.
534      GlobalInits.push_back(GlobalInitWorklist.back());
535    } else {
536      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
537        GlobalInitWorklist.back().first->setInitializer(C);
538      else
539        return Error("Global variable initializer is not a constant!");
540    }
541    GlobalInitWorklist.pop_back();
542  }
543
544  while (!AliasInitWorklist.empty()) {
545    unsigned ValID = AliasInitWorklist.back().second;
546    if (ValID >= ValueList.size()) {
547      AliasInits.push_back(AliasInitWorklist.back());
548    } else {
549      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
550        AliasInitWorklist.back().first->setAliasee(C);
551      else
552        return Error("Alias initializer is not a constant!");
553    }
554    AliasInitWorklist.pop_back();
555  }
556  return false;
557}
558
559
560bool BitcodeReader::ParseConstants() {
561  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
562    return Error("Malformed block record");
563
564  SmallVector<uint64_t, 64> Record;
565
566  // Read all the records for this value table.
567  const Type *CurTy = Type::Int32Ty;
568  unsigned NextCstNo = ValueList.size();
569  while (1) {
570    unsigned Code = Stream.ReadCode();
571    if (Code == bitc::END_BLOCK) {
572      if (NextCstNo != ValueList.size())
573        return Error("Invalid constant reference!");
574
575      if (Stream.ReadBlockEnd())
576        return Error("Error at end of constants block");
577      return false;
578    }
579
580    if (Code == bitc::ENTER_SUBBLOCK) {
581      // No known subblocks, always skip them.
582      Stream.ReadSubBlockID();
583      if (Stream.SkipBlock())
584        return Error("Malformed block record");
585      continue;
586    }
587
588    if (Code == bitc::DEFINE_ABBREV) {
589      Stream.ReadAbbrevRecord();
590      continue;
591    }
592
593    // Read a record.
594    Record.clear();
595    Value *V = 0;
596    switch (Stream.ReadRecord(Code, Record)) {
597    default:  // Default behavior: unknown constant
598    case bitc::CST_CODE_UNDEF:     // UNDEF
599      V = UndefValue::get(CurTy);
600      break;
601    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
602      if (Record.empty())
603        return Error("Malformed CST_SETTYPE record");
604      if (Record[0] >= TypeList.size())
605        return Error("Invalid Type ID in CST_SETTYPE record");
606      CurTy = TypeList[Record[0]];
607      continue;  // Skip the ValueList manipulation.
608    case bitc::CST_CODE_NULL:      // NULL
609      V = Constant::getNullValue(CurTy);
610      break;
611    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
612      if (!isa<IntegerType>(CurTy) || Record.empty())
613        return Error("Invalid CST_INTEGER record");
614      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
615      break;
616    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
617      if (!isa<IntegerType>(CurTy) || Record.empty())
618        return Error("Invalid WIDE_INTEGER record");
619
620      unsigned NumWords = Record.size();
621      SmallVector<uint64_t, 8> Words;
622      Words.resize(NumWords);
623      for (unsigned i = 0; i != NumWords; ++i)
624        Words[i] = DecodeSignRotatedValue(Record[i]);
625      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
626                                 NumWords, &Words[0]));
627      break;
628    }
629    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
630      if (Record.empty())
631        return Error("Invalid FLOAT record");
632      if (CurTy == Type::FloatTy)
633        V = ConstantFP::get(CurTy, APFloat(APInt(32, (uint32_t)Record[0])));
634      else if (CurTy == Type::DoubleTy)
635        V = ConstantFP::get(CurTy, APFloat(APInt(64, Record[0])));
636      else if (CurTy == Type::X86_FP80Ty)
637        V = ConstantFP::get(CurTy, APFloat(APInt(80, 2, &Record[0])));
638      else if (CurTy == Type::FP128Ty)
639        V = ConstantFP::get(CurTy, APFloat(APInt(128, 2, &Record[0]), true));
640      else if (CurTy == Type::PPC_FP128Ty)
641        V = ConstantFP::get(CurTy, APFloat(APInt(128, 2, &Record[0])));
642      else
643        V = UndefValue::get(CurTy);
644      break;
645    }
646
647    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
648      if (Record.empty())
649        return Error("Invalid CST_AGGREGATE record");
650
651      unsigned Size = Record.size();
652      std::vector<Constant*> Elts;
653
654      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
655        for (unsigned i = 0; i != Size; ++i)
656          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
657                                                     STy->getElementType(i)));
658        V = ConstantStruct::get(STy, Elts);
659      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
660        const Type *EltTy = ATy->getElementType();
661        for (unsigned i = 0; i != Size; ++i)
662          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
663        V = ConstantArray::get(ATy, Elts);
664      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
665        const Type *EltTy = VTy->getElementType();
666        for (unsigned i = 0; i != Size; ++i)
667          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
668        V = ConstantVector::get(Elts);
669      } else {
670        V = UndefValue::get(CurTy);
671      }
672      break;
673    }
674    case bitc::CST_CODE_STRING: { // STRING: [values]
675      if (Record.empty())
676        return Error("Invalid CST_AGGREGATE record");
677
678      const ArrayType *ATy = cast<ArrayType>(CurTy);
679      const Type *EltTy = ATy->getElementType();
680
681      unsigned Size = Record.size();
682      std::vector<Constant*> Elts;
683      for (unsigned i = 0; i != Size; ++i)
684        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
685      V = ConstantArray::get(ATy, Elts);
686      break;
687    }
688    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
689      if (Record.empty())
690        return Error("Invalid CST_AGGREGATE record");
691
692      const ArrayType *ATy = cast<ArrayType>(CurTy);
693      const Type *EltTy = ATy->getElementType();
694
695      unsigned Size = Record.size();
696      std::vector<Constant*> Elts;
697      for (unsigned i = 0; i != Size; ++i)
698        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
699      Elts.push_back(Constant::getNullValue(EltTy));
700      V = ConstantArray::get(ATy, Elts);
701      break;
702    }
703    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
704      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
705      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
706      if (Opc < 0) {
707        V = UndefValue::get(CurTy);  // Unknown binop.
708      } else {
709        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
710        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
711        V = ConstantExpr::get(Opc, LHS, RHS);
712      }
713      break;
714    }
715    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
716      if (Record.size() < 3) return Error("Invalid CE_CAST record");
717      int Opc = GetDecodedCastOpcode(Record[0]);
718      if (Opc < 0) {
719        V = UndefValue::get(CurTy);  // Unknown cast.
720      } else {
721        const Type *OpTy = getTypeByID(Record[1]);
722        if (!OpTy) return Error("Invalid CE_CAST record");
723        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
724        V = ConstantExpr::getCast(Opc, Op, CurTy);
725      }
726      break;
727    }
728    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
729      if (Record.size() & 1) return Error("Invalid CE_GEP record");
730      SmallVector<Constant*, 16> Elts;
731      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
732        const Type *ElTy = getTypeByID(Record[i]);
733        if (!ElTy) return Error("Invalid CE_GEP record");
734        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
735      }
736      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
737      break;
738    }
739    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
740      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
741      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
742                                                              Type::Int1Ty),
743                                  ValueList.getConstantFwdRef(Record[1],CurTy),
744                                  ValueList.getConstantFwdRef(Record[2],CurTy));
745      break;
746    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
747      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
748      const VectorType *OpTy =
749        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
750      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
751      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
752      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
753                                                  OpTy->getElementType());
754      V = ConstantExpr::getExtractElement(Op0, Op1);
755      break;
756    }
757    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
758      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
759      if (Record.size() < 3 || OpTy == 0)
760        return Error("Invalid CE_INSERTELT record");
761      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
762      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
763                                                  OpTy->getElementType());
764      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
765      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
766      break;
767    }
768    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
769      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
770      if (Record.size() < 3 || OpTy == 0)
771        return Error("Invalid CE_INSERTELT record");
772      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
773      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
774      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
775      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
776      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
777      break;
778    }
779    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
780      if (Record.size() < 4) return Error("Invalid CE_CMP record");
781      const Type *OpTy = getTypeByID(Record[0]);
782      if (OpTy == 0) return Error("Invalid CE_CMP record");
783      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
784      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
785
786      if (OpTy->isFloatingPoint())
787        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
788      else
789        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
790      break;
791    }
792    case bitc::CST_CODE_INLINEASM: {
793      if (Record.size() < 2) return Error("Invalid INLINEASM record");
794      std::string AsmStr, ConstrStr;
795      bool HasSideEffects = Record[0];
796      unsigned AsmStrSize = Record[1];
797      if (2+AsmStrSize >= Record.size())
798        return Error("Invalid INLINEASM record");
799      unsigned ConstStrSize = Record[2+AsmStrSize];
800      if (3+AsmStrSize+ConstStrSize > Record.size())
801        return Error("Invalid INLINEASM record");
802
803      for (unsigned i = 0; i != AsmStrSize; ++i)
804        AsmStr += (char)Record[2+i];
805      for (unsigned i = 0; i != ConstStrSize; ++i)
806        ConstrStr += (char)Record[3+AsmStrSize+i];
807      const PointerType *PTy = cast<PointerType>(CurTy);
808      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
809                         AsmStr, ConstrStr, HasSideEffects);
810      break;
811    }
812    }
813
814    ValueList.AssignValue(V, NextCstNo);
815    ++NextCstNo;
816  }
817}
818
819/// RememberAndSkipFunctionBody - When we see the block for a function body,
820/// remember where it is and then skip it.  This lets us lazily deserialize the
821/// functions.
822bool BitcodeReader::RememberAndSkipFunctionBody() {
823  // Get the function we are talking about.
824  if (FunctionsWithBodies.empty())
825    return Error("Insufficient function protos");
826
827  Function *Fn = FunctionsWithBodies.back();
828  FunctionsWithBodies.pop_back();
829
830  // Save the current stream state.
831  uint64_t CurBit = Stream.GetCurrentBitNo();
832  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
833
834  // Set the functions linkage to GhostLinkage so we know it is lazily
835  // deserialized.
836  Fn->setLinkage(GlobalValue::GhostLinkage);
837
838  // Skip over the function block for now.
839  if (Stream.SkipBlock())
840    return Error("Malformed block record");
841  return false;
842}
843
844bool BitcodeReader::ParseModule(const std::string &ModuleID) {
845  // Reject multiple MODULE_BLOCK's in a single bitstream.
846  if (TheModule)
847    return Error("Multiple MODULE_BLOCKs in same stream");
848
849  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
850    return Error("Malformed block record");
851
852  // Otherwise, create the module.
853  TheModule = new Module(ModuleID);
854
855  SmallVector<uint64_t, 64> Record;
856  std::vector<std::string> SectionTable;
857  std::vector<std::string> CollectorTable;
858
859  // Read all the records for this module.
860  while (!Stream.AtEndOfStream()) {
861    unsigned Code = Stream.ReadCode();
862    if (Code == bitc::END_BLOCK) {
863      if (Stream.ReadBlockEnd())
864        return Error("Error at end of module block");
865
866      // Patch the initializers for globals and aliases up.
867      ResolveGlobalAndAliasInits();
868      if (!GlobalInits.empty() || !AliasInits.empty())
869        return Error("Malformed global initializer set");
870      if (!FunctionsWithBodies.empty())
871        return Error("Too few function bodies found");
872
873      // Look for intrinsic functions which need to be upgraded at some point
874      for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
875           FI != FE; ++FI) {
876        if (Function* NewFn = UpgradeIntrinsicFunction(FI))
877          UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
878      }
879
880      // Force deallocation of memory for these vectors to favor the client that
881      // want lazy deserialization.
882      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
883      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
884      std::vector<Function*>().swap(FunctionsWithBodies);
885      return false;
886    }
887
888    if (Code == bitc::ENTER_SUBBLOCK) {
889      switch (Stream.ReadSubBlockID()) {
890      default:  // Skip unknown content.
891        if (Stream.SkipBlock())
892          return Error("Malformed block record");
893        break;
894      case bitc::BLOCKINFO_BLOCK_ID:
895        if (Stream.ReadBlockInfoBlock())
896          return Error("Malformed BlockInfoBlock");
897        break;
898      case bitc::PARAMATTR_BLOCK_ID:
899        if (ParseParamAttrBlock())
900          return true;
901        break;
902      case bitc::TYPE_BLOCK_ID:
903        if (ParseTypeTable())
904          return true;
905        break;
906      case bitc::TYPE_SYMTAB_BLOCK_ID:
907        if (ParseTypeSymbolTable())
908          return true;
909        break;
910      case bitc::VALUE_SYMTAB_BLOCK_ID:
911        if (ParseValueSymbolTable())
912          return true;
913        break;
914      case bitc::CONSTANTS_BLOCK_ID:
915        if (ParseConstants() || ResolveGlobalAndAliasInits())
916          return true;
917        break;
918      case bitc::FUNCTION_BLOCK_ID:
919        // If this is the first function body we've seen, reverse the
920        // FunctionsWithBodies list.
921        if (!HasReversedFunctionsWithBodies) {
922          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
923          HasReversedFunctionsWithBodies = true;
924        }
925
926        if (RememberAndSkipFunctionBody())
927          return true;
928        break;
929      }
930      continue;
931    }
932
933    if (Code == bitc::DEFINE_ABBREV) {
934      Stream.ReadAbbrevRecord();
935      continue;
936    }
937
938    // Read a record.
939    switch (Stream.ReadRecord(Code, Record)) {
940    default: break;  // Default behavior, ignore unknown content.
941    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
942      if (Record.size() < 1)
943        return Error("Malformed MODULE_CODE_VERSION");
944      // Only version #0 is supported so far.
945      if (Record[0] != 0)
946        return Error("Unknown bitstream version!");
947      break;
948    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
949      std::string S;
950      if (ConvertToString(Record, 0, S))
951        return Error("Invalid MODULE_CODE_TRIPLE record");
952      TheModule->setTargetTriple(S);
953      break;
954    }
955    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
956      std::string S;
957      if (ConvertToString(Record, 0, S))
958        return Error("Invalid MODULE_CODE_DATALAYOUT record");
959      TheModule->setDataLayout(S);
960      break;
961    }
962    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
963      std::string S;
964      if (ConvertToString(Record, 0, S))
965        return Error("Invalid MODULE_CODE_ASM record");
966      TheModule->setModuleInlineAsm(S);
967      break;
968    }
969    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
970      std::string S;
971      if (ConvertToString(Record, 0, S))
972        return Error("Invalid MODULE_CODE_DEPLIB record");
973      TheModule->addLibrary(S);
974      break;
975    }
976    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
977      std::string S;
978      if (ConvertToString(Record, 0, S))
979        return Error("Invalid MODULE_CODE_SECTIONNAME record");
980      SectionTable.push_back(S);
981      break;
982    }
983    case bitc::MODULE_CODE_COLLECTORNAME: {  // SECTIONNAME: [strchr x N]
984      std::string S;
985      if (ConvertToString(Record, 0, S))
986        return Error("Invalid MODULE_CODE_COLLECTORNAME record");
987      CollectorTable.push_back(S);
988      break;
989    }
990    // GLOBALVAR: [pointer type, isconst, initid,
991    //             linkage, alignment, section, visibility, threadlocal]
992    case bitc::MODULE_CODE_GLOBALVAR: {
993      if (Record.size() < 6)
994        return Error("Invalid MODULE_CODE_GLOBALVAR record");
995      const Type *Ty = getTypeByID(Record[0]);
996      if (!isa<PointerType>(Ty))
997        return Error("Global not a pointer type!");
998      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
999      Ty = cast<PointerType>(Ty)->getElementType();
1000
1001      bool isConstant = Record[1];
1002      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1003      unsigned Alignment = (1 << Record[4]) >> 1;
1004      std::string Section;
1005      if (Record[5]) {
1006        if (Record[5]-1 >= SectionTable.size())
1007          return Error("Invalid section ID");
1008        Section = SectionTable[Record[5]-1];
1009      }
1010      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1011      if (Record.size() > 6)
1012        Visibility = GetDecodedVisibility(Record[6]);
1013      bool isThreadLocal = false;
1014      if (Record.size() > 7)
1015        isThreadLocal = Record[7];
1016
1017      GlobalVariable *NewGV =
1018        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule,
1019                           isThreadLocal, AddressSpace);
1020      NewGV->setAlignment(Alignment);
1021      if (!Section.empty())
1022        NewGV->setSection(Section);
1023      NewGV->setVisibility(Visibility);
1024      NewGV->setThreadLocal(isThreadLocal);
1025
1026      ValueList.push_back(NewGV);
1027
1028      // Remember which value to use for the global initializer.
1029      if (unsigned InitID = Record[2])
1030        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1031      break;
1032    }
1033    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1034    //             alignment, section, visibility, collector]
1035    case bitc::MODULE_CODE_FUNCTION: {
1036      if (Record.size() < 8)
1037        return Error("Invalid MODULE_CODE_FUNCTION record");
1038      const Type *Ty = getTypeByID(Record[0]);
1039      if (!isa<PointerType>(Ty))
1040        return Error("Function not a pointer type!");
1041      const FunctionType *FTy =
1042        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1043      if (!FTy)
1044        return Error("Function not a pointer to function type!");
1045
1046      Function *Func = new Function(FTy, GlobalValue::ExternalLinkage,
1047                                    "", TheModule);
1048
1049      Func->setCallingConv(Record[1]);
1050      bool isProto = Record[2];
1051      Func->setLinkage(GetDecodedLinkage(Record[3]));
1052      const ParamAttrsList *PAL = getParamAttrs(Record[4]);
1053      Func->setParamAttrs(PAL);
1054
1055      Func->setAlignment((1 << Record[5]) >> 1);
1056      if (Record[6]) {
1057        if (Record[6]-1 >= SectionTable.size())
1058          return Error("Invalid section ID");
1059        Func->setSection(SectionTable[Record[6]-1]);
1060      }
1061      Func->setVisibility(GetDecodedVisibility(Record[7]));
1062      if (Record.size() > 8 && Record[8]) {
1063        if (Record[8]-1 > CollectorTable.size())
1064          return Error("Invalid collector ID");
1065        Func->setCollector(CollectorTable[Record[8]-1].c_str());
1066      }
1067
1068      ValueList.push_back(Func);
1069
1070      // If this is a function with a body, remember the prototype we are
1071      // creating now, so that we can match up the body with them later.
1072      if (!isProto)
1073        FunctionsWithBodies.push_back(Func);
1074      break;
1075    }
1076    // ALIAS: [alias type, aliasee val#, linkage]
1077    case bitc::MODULE_CODE_ALIAS: {
1078      if (Record.size() < 3)
1079        return Error("Invalid MODULE_ALIAS record");
1080      const Type *Ty = getTypeByID(Record[0]);
1081      if (!isa<PointerType>(Ty))
1082        return Error("Function not a pointer type!");
1083
1084      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1085                                           "", 0, TheModule);
1086      ValueList.push_back(NewGA);
1087      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1088      break;
1089    }
1090    /// MODULE_CODE_PURGEVALS: [numvals]
1091    case bitc::MODULE_CODE_PURGEVALS:
1092      // Trim down the value list to the specified size.
1093      if (Record.size() < 1 || Record[0] > ValueList.size())
1094        return Error("Invalid MODULE_PURGEVALS record");
1095      ValueList.shrinkTo(Record[0]);
1096      break;
1097    }
1098    Record.clear();
1099  }
1100
1101  return Error("Premature end of bitstream");
1102}
1103
1104
1105bool BitcodeReader::ParseBitcode() {
1106  TheModule = 0;
1107
1108  if (Buffer->getBufferSize() & 3)
1109    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1110
1111  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1112  Stream.init(BufPtr, BufPtr+Buffer->getBufferSize());
1113
1114  // Sniff for the signature.
1115  if (Stream.Read(8) != 'B' ||
1116      Stream.Read(8) != 'C' ||
1117      Stream.Read(4) != 0x0 ||
1118      Stream.Read(4) != 0xC ||
1119      Stream.Read(4) != 0xE ||
1120      Stream.Read(4) != 0xD)
1121    return Error("Invalid bitcode signature");
1122
1123  // We expect a number of well-defined blocks, though we don't necessarily
1124  // need to understand them all.
1125  while (!Stream.AtEndOfStream()) {
1126    unsigned Code = Stream.ReadCode();
1127
1128    if (Code != bitc::ENTER_SUBBLOCK)
1129      return Error("Invalid record at top-level");
1130
1131    unsigned BlockID = Stream.ReadSubBlockID();
1132
1133    // We only know the MODULE subblock ID.
1134    switch (BlockID) {
1135    case bitc::BLOCKINFO_BLOCK_ID:
1136      if (Stream.ReadBlockInfoBlock())
1137        return Error("Malformed BlockInfoBlock");
1138      break;
1139    case bitc::MODULE_BLOCK_ID:
1140      if (ParseModule(Buffer->getBufferIdentifier()))
1141        return true;
1142      break;
1143    default:
1144      if (Stream.SkipBlock())
1145        return Error("Malformed block record");
1146      break;
1147    }
1148  }
1149
1150  return false;
1151}
1152
1153
1154/// ParseFunctionBody - Lazily parse the specified function body block.
1155bool BitcodeReader::ParseFunctionBody(Function *F) {
1156  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1157    return Error("Malformed block record");
1158
1159  unsigned ModuleValueListSize = ValueList.size();
1160
1161  // Add all the function arguments to the value table.
1162  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1163    ValueList.push_back(I);
1164
1165  unsigned NextValueNo = ValueList.size();
1166  BasicBlock *CurBB = 0;
1167  unsigned CurBBNo = 0;
1168
1169  // Read all the records.
1170  SmallVector<uint64_t, 64> Record;
1171  while (1) {
1172    unsigned Code = Stream.ReadCode();
1173    if (Code == bitc::END_BLOCK) {
1174      if (Stream.ReadBlockEnd())
1175        return Error("Error at end of function block");
1176      break;
1177    }
1178
1179    if (Code == bitc::ENTER_SUBBLOCK) {
1180      switch (Stream.ReadSubBlockID()) {
1181      default:  // Skip unknown content.
1182        if (Stream.SkipBlock())
1183          return Error("Malformed block record");
1184        break;
1185      case bitc::CONSTANTS_BLOCK_ID:
1186        if (ParseConstants()) return true;
1187        NextValueNo = ValueList.size();
1188        break;
1189      case bitc::VALUE_SYMTAB_BLOCK_ID:
1190        if (ParseValueSymbolTable()) return true;
1191        break;
1192      }
1193      continue;
1194    }
1195
1196    if (Code == bitc::DEFINE_ABBREV) {
1197      Stream.ReadAbbrevRecord();
1198      continue;
1199    }
1200
1201    // Read a record.
1202    Record.clear();
1203    Instruction *I = 0;
1204    switch (Stream.ReadRecord(Code, Record)) {
1205    default: // Default behavior: reject
1206      return Error("Unknown instruction");
1207    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1208      if (Record.size() < 1 || Record[0] == 0)
1209        return Error("Invalid DECLAREBLOCKS record");
1210      // Create all the basic blocks for the function.
1211      FunctionBBs.resize(Record[0]);
1212      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1213        FunctionBBs[i] = new BasicBlock("", F);
1214      CurBB = FunctionBBs[0];
1215      continue;
1216
1217    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1218      unsigned OpNum = 0;
1219      Value *LHS, *RHS;
1220      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1221          getValue(Record, OpNum, LHS->getType(), RHS) ||
1222          OpNum+1 != Record.size())
1223        return Error("Invalid BINOP record");
1224
1225      int Opc = GetDecodedBinaryOpcode(Record[OpNum], LHS->getType());
1226      if (Opc == -1) return Error("Invalid BINOP record");
1227      I = BinaryOperator::create((Instruction::BinaryOps)Opc, LHS, RHS);
1228      break;
1229    }
1230    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
1231      unsigned OpNum = 0;
1232      Value *Op;
1233      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1234          OpNum+2 != Record.size())
1235        return Error("Invalid CAST record");
1236
1237      const Type *ResTy = getTypeByID(Record[OpNum]);
1238      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
1239      if (Opc == -1 || ResTy == 0)
1240        return Error("Invalid CAST record");
1241      I = CastInst::create((Instruction::CastOps)Opc, Op, ResTy);
1242      break;
1243    }
1244    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
1245      unsigned OpNum = 0;
1246      Value *BasePtr;
1247      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
1248        return Error("Invalid GEP record");
1249
1250      SmallVector<Value*, 16> GEPIdx;
1251      while (OpNum != Record.size()) {
1252        Value *Op;
1253        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1254          return Error("Invalid GEP record");
1255        GEPIdx.push_back(Op);
1256      }
1257
1258      I = new GetElementPtrInst(BasePtr, GEPIdx.begin(), GEPIdx.end());
1259      break;
1260    }
1261
1262    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
1263      unsigned OpNum = 0;
1264      Value *TrueVal, *FalseVal, *Cond;
1265      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
1266          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
1267          getValue(Record, OpNum, Type::Int1Ty, Cond))
1268        return Error("Invalid SELECT record");
1269
1270      I = new SelectInst(Cond, TrueVal, FalseVal);
1271      break;
1272    }
1273
1274    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1275      unsigned OpNum = 0;
1276      Value *Vec, *Idx;
1277      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1278          getValue(Record, OpNum, Type::Int32Ty, Idx))
1279        return Error("Invalid EXTRACTELT record");
1280      I = new ExtractElementInst(Vec, Idx);
1281      break;
1282    }
1283
1284    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1285      unsigned OpNum = 0;
1286      Value *Vec, *Elt, *Idx;
1287      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1288          getValue(Record, OpNum,
1289                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
1290          getValue(Record, OpNum, Type::Int32Ty, Idx))
1291        return Error("Invalid INSERTELT record");
1292      I = new InsertElementInst(Vec, Elt, Idx);
1293      break;
1294    }
1295
1296    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
1297      unsigned OpNum = 0;
1298      Value *Vec1, *Vec2, *Mask;
1299      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
1300          getValue(Record, OpNum, Vec1->getType(), Vec2))
1301        return Error("Invalid SHUFFLEVEC record");
1302
1303      const Type *MaskTy =
1304        VectorType::get(Type::Int32Ty,
1305                        cast<VectorType>(Vec1->getType())->getNumElements());
1306
1307      if (getValue(Record, OpNum, MaskTy, Mask))
1308        return Error("Invalid SHUFFLEVEC record");
1309      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1310      break;
1311    }
1312
1313    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1314      unsigned OpNum = 0;
1315      Value *LHS, *RHS;
1316      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1317          getValue(Record, OpNum, LHS->getType(), RHS) ||
1318          OpNum+1 != Record.size())
1319        return Error("Invalid CMP record");
1320
1321      if (LHS->getType()->isFPOrFPVector())
1322        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1323      else
1324        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1325      break;
1326    }
1327
1328    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1329      if (Record.size() == 0) {
1330        I = new ReturnInst();
1331        break;
1332      } else {
1333        unsigned OpNum = 0;
1334        Value *Op;
1335        if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1336            OpNum != Record.size())
1337          return Error("Invalid RET record");
1338        I = new ReturnInst(Op);
1339        break;
1340      }
1341    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1342      if (Record.size() != 1 && Record.size() != 3)
1343        return Error("Invalid BR record");
1344      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1345      if (TrueDest == 0)
1346        return Error("Invalid BR record");
1347
1348      if (Record.size() == 1)
1349        I = new BranchInst(TrueDest);
1350      else {
1351        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1352        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1353        if (FalseDest == 0 || Cond == 0)
1354          return Error("Invalid BR record");
1355        I = new BranchInst(TrueDest, FalseDest, Cond);
1356      }
1357      break;
1358    }
1359    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1360      if (Record.size() < 3 || (Record.size() & 1) == 0)
1361        return Error("Invalid SWITCH record");
1362      const Type *OpTy = getTypeByID(Record[0]);
1363      Value *Cond = getFnValueByID(Record[1], OpTy);
1364      BasicBlock *Default = getBasicBlock(Record[2]);
1365      if (OpTy == 0 || Cond == 0 || Default == 0)
1366        return Error("Invalid SWITCH record");
1367      unsigned NumCases = (Record.size()-3)/2;
1368      SwitchInst *SI = new SwitchInst(Cond, Default, NumCases);
1369      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1370        ConstantInt *CaseVal =
1371          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1372        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1373        if (CaseVal == 0 || DestBB == 0) {
1374          delete SI;
1375          return Error("Invalid SWITCH record!");
1376        }
1377        SI->addCase(CaseVal, DestBB);
1378      }
1379      I = SI;
1380      break;
1381    }
1382
1383    case bitc::FUNC_CODE_INST_INVOKE: {
1384      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
1385      if (Record.size() < 4) return Error("Invalid INVOKE record");
1386      const ParamAttrsList *PAL = getParamAttrs(Record[0]);
1387      unsigned CCInfo = Record[1];
1388      BasicBlock *NormalBB = getBasicBlock(Record[2]);
1389      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
1390
1391      unsigned OpNum = 4;
1392      Value *Callee;
1393      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1394        return Error("Invalid INVOKE record");
1395
1396      const PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
1397      const FunctionType *FTy = !CalleeTy ? 0 :
1398        dyn_cast<FunctionType>(CalleeTy->getElementType());
1399
1400      // Check that the right number of fixed parameters are here.
1401      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
1402          Record.size() < OpNum+FTy->getNumParams())
1403        return Error("Invalid INVOKE record");
1404
1405      SmallVector<Value*, 16> Ops;
1406      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1407        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1408        if (Ops.back() == 0) return Error("Invalid INVOKE record");
1409      }
1410
1411      if (!FTy->isVarArg()) {
1412        if (Record.size() != OpNum)
1413          return Error("Invalid INVOKE record");
1414      } else {
1415        // Read type/value pairs for varargs params.
1416        while (OpNum != Record.size()) {
1417          Value *Op;
1418          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1419            return Error("Invalid INVOKE record");
1420          Ops.push_back(Op);
1421        }
1422      }
1423
1424      I = new InvokeInst(Callee, NormalBB, UnwindBB, Ops.begin(), Ops.end());
1425      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1426      cast<InvokeInst>(I)->setParamAttrs(PAL);
1427      break;
1428    }
1429    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1430      I = new UnwindInst();
1431      break;
1432    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1433      I = new UnreachableInst();
1434      break;
1435    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
1436      if (Record.size() < 1 || ((Record.size()-1)&1))
1437        return Error("Invalid PHI record");
1438      const Type *Ty = getTypeByID(Record[0]);
1439      if (!Ty) return Error("Invalid PHI record");
1440
1441      PHINode *PN = new PHINode(Ty);
1442      PN->reserveOperandSpace(Record.size()-1);
1443
1444      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
1445        Value *V = getFnValueByID(Record[1+i], Ty);
1446        BasicBlock *BB = getBasicBlock(Record[2+i]);
1447        if (!V || !BB) return Error("Invalid PHI record");
1448        PN->addIncoming(V, BB);
1449      }
1450      I = PN;
1451      break;
1452    }
1453
1454    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1455      if (Record.size() < 3)
1456        return Error("Invalid MALLOC record");
1457      const PointerType *Ty =
1458        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1459      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1460      unsigned Align = Record[2];
1461      if (!Ty || !Size) return Error("Invalid MALLOC record");
1462      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1463      break;
1464    }
1465    case bitc::FUNC_CODE_INST_FREE: { // FREE: [op, opty]
1466      unsigned OpNum = 0;
1467      Value *Op;
1468      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1469          OpNum != Record.size())
1470        return Error("Invalid FREE record");
1471      I = new FreeInst(Op);
1472      break;
1473    }
1474    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1475      if (Record.size() < 3)
1476        return Error("Invalid ALLOCA record");
1477      const PointerType *Ty =
1478        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1479      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1480      unsigned Align = Record[2];
1481      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1482      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1483      break;
1484    }
1485    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1486      unsigned OpNum = 0;
1487      Value *Op;
1488      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1489          OpNum+2 != Record.size())
1490        return Error("Invalid LOAD record");
1491
1492      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1493      break;
1494    }
1495    case bitc::FUNC_CODE_INST_STORE2: { // STORE2:[ptrty, ptr, val, align, vol]
1496      unsigned OpNum = 0;
1497      Value *Val, *Ptr;
1498      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
1499          getValue(Record, OpNum,
1500                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
1501          OpNum+2 != Record.size())
1502        return Error("Invalid STORE record");
1503
1504      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1505      break;
1506    }
1507    case bitc::FUNC_CODE_INST_STORE: { // STORE:[val, valty, ptr, align, vol]
1508      // FIXME: Legacy form of store instruction. Should be removed in LLVM 3.0.
1509      unsigned OpNum = 0;
1510      Value *Val, *Ptr;
1511      if (getValueTypePair(Record, OpNum, NextValueNo, Val) ||
1512          getValue(Record, OpNum, PointerType::getUnqual(Val->getType()), Ptr)||
1513          OpNum+2 != Record.size())
1514        return Error("Invalid STORE record");
1515
1516      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1517      break;
1518    }
1519    case bitc::FUNC_CODE_INST_CALL: {
1520      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
1521      if (Record.size() < 3)
1522        return Error("Invalid CALL record");
1523
1524      const ParamAttrsList *PAL = getParamAttrs(Record[0]);
1525      unsigned CCInfo = Record[1];
1526
1527      unsigned OpNum = 2;
1528      Value *Callee;
1529      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1530        return Error("Invalid CALL record");
1531
1532      const PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
1533      const FunctionType *FTy = 0;
1534      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1535      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
1536        return Error("Invalid CALL record");
1537
1538      SmallVector<Value*, 16> Args;
1539      // Read the fixed params.
1540      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1541        if (FTy->getParamType(i)->getTypeID()==Type::LabelTyID)
1542          Args.push_back(getBasicBlock(Record[OpNum]));
1543        else
1544          Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1545        if (Args.back() == 0) return Error("Invalid CALL record");
1546      }
1547
1548      // Read type/value pairs for varargs params.
1549      if (!FTy->isVarArg()) {
1550        if (OpNum != Record.size())
1551          return Error("Invalid CALL record");
1552      } else {
1553        while (OpNum != Record.size()) {
1554          Value *Op;
1555          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1556            return Error("Invalid CALL record");
1557          Args.push_back(Op);
1558        }
1559      }
1560
1561      I = new CallInst(Callee, Args.begin(), Args.end());
1562      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1563      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1564      cast<CallInst>(I)->setParamAttrs(PAL);
1565      break;
1566    }
1567    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1568      if (Record.size() < 3)
1569        return Error("Invalid VAARG record");
1570      const Type *OpTy = getTypeByID(Record[0]);
1571      Value *Op = getFnValueByID(Record[1], OpTy);
1572      const Type *ResTy = getTypeByID(Record[2]);
1573      if (!OpTy || !Op || !ResTy)
1574        return Error("Invalid VAARG record");
1575      I = new VAArgInst(Op, ResTy);
1576      break;
1577    }
1578    }
1579
1580    // Add instruction to end of current BB.  If there is no current BB, reject
1581    // this file.
1582    if (CurBB == 0) {
1583      delete I;
1584      return Error("Invalid instruction with no BB");
1585    }
1586    CurBB->getInstList().push_back(I);
1587
1588    // If this was a terminator instruction, move to the next block.
1589    if (isa<TerminatorInst>(I)) {
1590      ++CurBBNo;
1591      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1592    }
1593
1594    // Non-void values get registered in the value table for future use.
1595    if (I && I->getType() != Type::VoidTy)
1596      ValueList.AssignValue(I, NextValueNo++);
1597  }
1598
1599  // Check the function list for unresolved values.
1600  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1601    if (A->getParent() == 0) {
1602      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1603      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1604        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1605          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1606          delete A;
1607        }
1608      }
1609      return Error("Never resolved value found in function!");
1610    }
1611  }
1612
1613  // Trim the value list down to the size it was before we parsed this function.
1614  ValueList.shrinkTo(ModuleValueListSize);
1615  std::vector<BasicBlock*>().swap(FunctionBBs);
1616
1617  return false;
1618}
1619
1620//===----------------------------------------------------------------------===//
1621// ModuleProvider implementation
1622//===----------------------------------------------------------------------===//
1623
1624
1625bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1626  // If it already is material, ignore the request.
1627  if (!F->hasNotBeenReadFromBitcode()) return false;
1628
1629  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1630    DeferredFunctionInfo.find(F);
1631  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1632
1633  // Move the bit stream to the saved position of the deferred function body and
1634  // restore the real linkage type for the function.
1635  Stream.JumpToBit(DFII->second.first);
1636  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1637
1638  if (ParseFunctionBody(F)) {
1639    if (ErrInfo) *ErrInfo = ErrorString;
1640    return true;
1641  }
1642
1643  // Upgrade any old intrinsic calls in the function.
1644  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
1645       E = UpgradedIntrinsics.end(); I != E; ++I) {
1646    if (I->first != I->second) {
1647      for (Value::use_iterator UI = I->first->use_begin(),
1648           UE = I->first->use_end(); UI != UE; ) {
1649        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1650          UpgradeIntrinsicCall(CI, I->second);
1651      }
1652    }
1653  }
1654
1655  return false;
1656}
1657
1658void BitcodeReader::dematerializeFunction(Function *F) {
1659  // If this function isn't materialized, or if it is a proto, this is a noop.
1660  if (F->hasNotBeenReadFromBitcode() || F->isDeclaration())
1661    return;
1662
1663  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
1664
1665  // Just forget the function body, we can remat it later.
1666  F->deleteBody();
1667  F->setLinkage(GlobalValue::GhostLinkage);
1668}
1669
1670
1671Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
1672  for (DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1673       DeferredFunctionInfo.begin(), E = DeferredFunctionInfo.end(); I != E;
1674       ++I) {
1675    Function *F = I->first;
1676    if (F->hasNotBeenReadFromBitcode() &&
1677        materializeFunction(F, ErrInfo))
1678      return 0;
1679  }
1680
1681  // Upgrade any intrinsic calls that slipped through (should not happen!) and
1682  // delete the old functions to clean up. We can't do this unless the entire
1683  // module is materialized because there could always be another function body
1684  // with calls to the old function.
1685  for (std::vector<std::pair<Function*, Function*> >::iterator I =
1686       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
1687    if (I->first != I->second) {
1688      for (Value::use_iterator UI = I->first->use_begin(),
1689           UE = I->first->use_end(); UI != UE; ) {
1690        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1691          UpgradeIntrinsicCall(CI, I->second);
1692      }
1693      ValueList.replaceUsesOfWith(I->first, I->second);
1694      I->first->eraseFromParent();
1695    }
1696  }
1697  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
1698
1699  return TheModule;
1700}
1701
1702
1703/// This method is provided by the parent ModuleProvde class and overriden
1704/// here. It simply releases the module from its provided and frees up our
1705/// state.
1706/// @brief Release our hold on the generated module
1707Module *BitcodeReader::releaseModule(std::string *ErrInfo) {
1708  // Since we're losing control of this Module, we must hand it back complete
1709  Module *M = ModuleProvider::releaseModule(ErrInfo);
1710  FreeState();
1711  return M;
1712}
1713
1714
1715//===----------------------------------------------------------------------===//
1716// External interface
1717//===----------------------------------------------------------------------===//
1718
1719/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1720///
1721ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1722                                               std::string *ErrMsg) {
1723  BitcodeReader *R = new BitcodeReader(Buffer);
1724  if (R->ParseBitcode()) {
1725    if (ErrMsg)
1726      *ErrMsg = R->getErrorString();
1727
1728    // Don't let the BitcodeReader dtor delete 'Buffer'.
1729    R->releaseMemoryBuffer();
1730    delete R;
1731    return 0;
1732  }
1733  return R;
1734}
1735
1736/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
1737/// If an error occurs, return null and fill in *ErrMsg if non-null.
1738Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
1739  BitcodeReader *R;
1740  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
1741  if (!R) return 0;
1742
1743  // Read in the entire module.
1744  Module *M = R->materializeModule(ErrMsg);
1745
1746  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
1747  // there was an error.
1748  R->releaseMemoryBuffer();
1749
1750  // If there was no error, tell ModuleProvider not to delete it when its dtor
1751  // is run.
1752  if (M)
1753    M = R->releaseModule(ErrMsg);
1754
1755  delete R;
1756  return M;
1757}
1758