BitcodeReader.cpp revision e4977cf750eaff28275429191821420c20b0c64f 
1//===- BitcodeReader.cpp - Internal BitcodeReader implementation ----------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This header defines the BitcodeReader class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Bitcode/ReaderWriter.h"
15#include "BitcodeReader.h"
16#include "llvm/Constants.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/InlineAsm.h"
19#include "llvm/Instructions.h"
20#include "llvm/Module.h"
21#include "llvm/AutoUpgrade.h"
22#include "llvm/ADT/SmallString.h"
23#include "llvm/ADT/SmallVector.h"
24#include "llvm/Support/MathExtras.h"
25#include "llvm/Support/MemoryBuffer.h"
26#include "llvm/OperandTraits.h"
27using namespace llvm;
28
29void BitcodeReader::FreeState() {
30  delete Buffer;
31  Buffer = 0;
32  std::vector<PATypeHolder>().swap(TypeList);
33  ValueList.clear();
34
35  std::vector<PAListPtr>().swap(ParamAttrs);
36  std::vector<BasicBlock*>().swap(FunctionBBs);
37  std::vector<Function*>().swap(FunctionsWithBodies);
38  DeferredFunctionInfo.clear();
39}
40
41//===----------------------------------------------------------------------===//
42//  Helper functions to implement forward reference resolution, etc.
43//===----------------------------------------------------------------------===//
44
45/// ConvertToString - Convert a string from a record into an std::string, return
46/// true on failure.
47template<typename StrTy>
48static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
49                            StrTy &Result) {
50  if (Idx > Record.size())
51    return true;
52
53  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
54    Result += (char)Record[i];
55  return false;
56}
57
58static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
59  switch (Val) {
60  default: // Map unknown/new linkages to external
61  case 0: return GlobalValue::ExternalLinkage;
62  case 1: return GlobalValue::WeakLinkage;
63  case 2: return GlobalValue::AppendingLinkage;
64  case 3: return GlobalValue::InternalLinkage;
65  case 4: return GlobalValue::LinkOnceLinkage;
66  case 5: return GlobalValue::DLLImportLinkage;
67  case 6: return GlobalValue::DLLExportLinkage;
68  case 7: return GlobalValue::ExternalWeakLinkage;
69  case 8: return GlobalValue::CommonLinkage;
70  }
71}
72
73static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
74  switch (Val) {
75  default: // Map unknown visibilities to default.
76  case 0: return GlobalValue::DefaultVisibility;
77  case 1: return GlobalValue::HiddenVisibility;
78  case 2: return GlobalValue::ProtectedVisibility;
79  }
80}
81
82static int GetDecodedCastOpcode(unsigned Val) {
83  switch (Val) {
84  default: return -1;
85  case bitc::CAST_TRUNC   : return Instruction::Trunc;
86  case bitc::CAST_ZEXT    : return Instruction::ZExt;
87  case bitc::CAST_SEXT    : return Instruction::SExt;
88  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
89  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
90  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
91  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
92  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
93  case bitc::CAST_FPEXT   : return Instruction::FPExt;
94  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
95  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
96  case bitc::CAST_BITCAST : return Instruction::BitCast;
97  }
98}
99static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
100  switch (Val) {
101  default: return -1;
102  case bitc::BINOP_ADD:  return Instruction::Add;
103  case bitc::BINOP_SUB:  return Instruction::Sub;
104  case bitc::BINOP_MUL:  return Instruction::Mul;
105  case bitc::BINOP_UDIV: return Instruction::UDiv;
106  case bitc::BINOP_SDIV:
107    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
108  case bitc::BINOP_UREM: return Instruction::URem;
109  case bitc::BINOP_SREM:
110    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
111  case bitc::BINOP_SHL:  return Instruction::Shl;
112  case bitc::BINOP_LSHR: return Instruction::LShr;
113  case bitc::BINOP_ASHR: return Instruction::AShr;
114  case bitc::BINOP_AND:  return Instruction::And;
115  case bitc::BINOP_OR:   return Instruction::Or;
116  case bitc::BINOP_XOR:  return Instruction::Xor;
117  }
118}
119
120namespace llvm {
121namespace {
122  /// @brief A class for maintaining the slot number definition
123  /// as a placeholder for the actual definition for forward constants defs.
124  class ConstantPlaceHolder : public ConstantExpr {
125    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
126    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
127  public:
128    // allocate space for exactly one operand
129    void *operator new(size_t s) {
130      return User::operator new(s, 1);
131    }
132    explicit ConstantPlaceHolder(const Type *Ty)
133      : ConstantExpr(Ty, Instruction::UserOp1, &Op<0>(), 1) {
134      Op<0>() = UndefValue::get(Type::Int32Ty);
135    }
136    /// Provide fast operand accessors
137    DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
138  };
139}
140
141
142  // FIXME: can we inherit this from ConstantExpr?
143template <>
144struct OperandTraits<ConstantPlaceHolder> : FixedNumOperandTraits<1> {
145};
146
147DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantPlaceHolder, Value)
148}
149
150void BitcodeReaderValueList::resize(unsigned Desired) {
151  if (Desired > Capacity) {
152    // Since we expect many values to come from the bitcode file we better
153    // allocate the double amount, so that the array size grows exponentially
154    // at each reallocation.  Also, add a small amount of 100 extra elements
155    // each time, to reallocate less frequently when the array is still small.
156    //
157    Capacity = Desired * 2 + 100;
158    Use *New = allocHungoffUses(Capacity);
159    Use *Old = OperandList;
160    unsigned Ops = getNumOperands();
161    for (int i(Ops - 1); i >= 0; --i)
162      New[i] = Old[i].get();
163    OperandList = New;
164    if (Old) Use::zap(Old, Old + Ops, true);
165  }
166}
167
168Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
169                                                    const Type *Ty) {
170  if (Idx >= size()) {
171    // Insert a bunch of null values.
172    resize(Idx + 1);
173    NumOperands = Idx+1;
174  }
175
176  if (Value *V = OperandList[Idx]) {
177    assert(Ty == V->getType() && "Type mismatch in constant table!");
178    return cast<Constant>(V);
179  }
180
181  // Create and return a placeholder, which will later be RAUW'd.
182  Constant *C = new ConstantPlaceHolder(Ty);
183  OperandList[Idx].init(C, this);
184  return C;
185}
186
187Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
188  if (Idx >= size()) {
189    // Insert a bunch of null values.
190    resize(Idx + 1);
191    NumOperands = Idx+1;
192  }
193
194  if (Value *V = OperandList[Idx]) {
195    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
196    return V;
197  }
198
199  // No type specified, must be invalid reference.
200  if (Ty == 0) return 0;
201
202  // Create and return a placeholder, which will later be RAUW'd.
203  Value *V = new Argument(Ty);
204  OperandList[Idx].init(V, this);
205  return V;
206}
207
208
209const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
210  // If the TypeID is in range, return it.
211  if (ID < TypeList.size())
212    return TypeList[ID].get();
213  if (!isTypeTable) return 0;
214
215  // The type table allows forward references.  Push as many Opaque types as
216  // needed to get up to ID.
217  while (TypeList.size() <= ID)
218    TypeList.push_back(OpaqueType::get());
219  return TypeList.back().get();
220}
221
222//===----------------------------------------------------------------------===//
223//  Functions for parsing blocks from the bitcode file
224//===----------------------------------------------------------------------===//
225
226bool BitcodeReader::ParseParamAttrBlock() {
227  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
228    return Error("Malformed block record");
229
230  if (!ParamAttrs.empty())
231    return Error("Multiple PARAMATTR blocks found!");
232
233  SmallVector<uint64_t, 64> Record;
234
235  SmallVector<ParamAttrsWithIndex, 8> Attrs;
236
237  // Read all the records.
238  while (1) {
239    unsigned Code = Stream.ReadCode();
240    if (Code == bitc::END_BLOCK) {
241      if (Stream.ReadBlockEnd())
242        return Error("Error at end of PARAMATTR block");
243      return false;
244    }
245
246    if (Code == bitc::ENTER_SUBBLOCK) {
247      // No known subblocks, always skip them.
248      Stream.ReadSubBlockID();
249      if (Stream.SkipBlock())
250        return Error("Malformed block record");
251      continue;
252    }
253
254    if (Code == bitc::DEFINE_ABBREV) {
255      Stream.ReadAbbrevRecord();
256      continue;
257    }
258
259    // Read a record.
260    Record.clear();
261    switch (Stream.ReadRecord(Code, Record)) {
262    default:  // Default behavior: ignore.
263      break;
264    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
265      if (Record.size() & 1)
266        return Error("Invalid ENTRY record");
267
268      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
269        if (Record[i+1] != ParamAttr::None)
270          Attrs.push_back(ParamAttrsWithIndex::get(Record[i], Record[i+1]));
271      }
272
273      ParamAttrs.push_back(PAListPtr::get(Attrs.begin(), Attrs.end()));
274      Attrs.clear();
275      break;
276    }
277    }
278  }
279}
280
281
282bool BitcodeReader::ParseTypeTable() {
283  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID))
284    return Error("Malformed block record");
285
286  if (!TypeList.empty())
287    return Error("Multiple TYPE_BLOCKs found!");
288
289  SmallVector<uint64_t, 64> Record;
290  unsigned NumRecords = 0;
291
292  // Read all the records for this type table.
293  while (1) {
294    unsigned Code = Stream.ReadCode();
295    if (Code == bitc::END_BLOCK) {
296      if (NumRecords != TypeList.size())
297        return Error("Invalid type forward reference in TYPE_BLOCK");
298      if (Stream.ReadBlockEnd())
299        return Error("Error at end of type table block");
300      return false;
301    }
302
303    if (Code == bitc::ENTER_SUBBLOCK) {
304      // No known subblocks, always skip them.
305      Stream.ReadSubBlockID();
306      if (Stream.SkipBlock())
307        return Error("Malformed block record");
308      continue;
309    }
310
311    if (Code == bitc::DEFINE_ABBREV) {
312      Stream.ReadAbbrevRecord();
313      continue;
314    }
315
316    // Read a record.
317    Record.clear();
318    const Type *ResultTy = 0;
319    switch (Stream.ReadRecord(Code, Record)) {
320    default:  // Default behavior: unknown type.
321      ResultTy = 0;
322      break;
323    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
324      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
325      // type list.  This allows us to reserve space.
326      if (Record.size() < 1)
327        return Error("Invalid TYPE_CODE_NUMENTRY record");
328      TypeList.reserve(Record[0]);
329      continue;
330    case bitc::TYPE_CODE_VOID:      // VOID
331      ResultTy = Type::VoidTy;
332      break;
333    case bitc::TYPE_CODE_FLOAT:     // FLOAT
334      ResultTy = Type::FloatTy;
335      break;
336    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
337      ResultTy = Type::DoubleTy;
338      break;
339    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
340      ResultTy = Type::X86_FP80Ty;
341      break;
342    case bitc::TYPE_CODE_FP128:     // FP128
343      ResultTy = Type::FP128Ty;
344      break;
345    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
346      ResultTy = Type::PPC_FP128Ty;
347      break;
348    case bitc::TYPE_CODE_LABEL:     // LABEL
349      ResultTy = Type::LabelTy;
350      break;
351    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
352      ResultTy = 0;
353      break;
354    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
355      if (Record.size() < 1)
356        return Error("Invalid Integer type record");
357
358      ResultTy = IntegerType::get(Record[0]);
359      break;
360    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
361                                    //          [pointee type, address space]
362      if (Record.size() < 1)
363        return Error("Invalid POINTER type record");
364      unsigned AddressSpace = 0;
365      if (Record.size() == 2)
366        AddressSpace = Record[1];
367      ResultTy = PointerType::get(getTypeByID(Record[0], true), AddressSpace);
368      break;
369    }
370    case bitc::TYPE_CODE_FUNCTION: {
371      // FIXME: attrid is dead, remove it in LLVM 3.0
372      // FUNCTION: [vararg, attrid, retty, paramty x N]
373      if (Record.size() < 3)
374        return Error("Invalid FUNCTION type record");
375      std::vector<const Type*> ArgTys;
376      for (unsigned i = 3, e = Record.size(); i != e; ++i)
377        ArgTys.push_back(getTypeByID(Record[i], true));
378
379      ResultTy = FunctionType::get(getTypeByID(Record[2], true), ArgTys,
380                                   Record[0]);
381      break;
382    }
383    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, eltty x N]
384      if (Record.size() < 1)
385        return Error("Invalid STRUCT type record");
386      std::vector<const Type*> EltTys;
387      for (unsigned i = 1, e = Record.size(); i != e; ++i)
388        EltTys.push_back(getTypeByID(Record[i], true));
389      ResultTy = StructType::get(EltTys, Record[0]);
390      break;
391    }
392    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
393      if (Record.size() < 2)
394        return Error("Invalid ARRAY type record");
395      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
396      break;
397    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
398      if (Record.size() < 2)
399        return Error("Invalid VECTOR type record");
400      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
401      break;
402    }
403
404    if (NumRecords == TypeList.size()) {
405      // If this is a new type slot, just append it.
406      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
407      ++NumRecords;
408    } else if (ResultTy == 0) {
409      // Otherwise, this was forward referenced, so an opaque type was created,
410      // but the result type is actually just an opaque.  Leave the one we
411      // created previously.
412      ++NumRecords;
413    } else {
414      // Otherwise, this was forward referenced, so an opaque type was created.
415      // Resolve the opaque type to the real type now.
416      assert(NumRecords < TypeList.size() && "Typelist imbalance");
417      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
418
419      // Don't directly push the new type on the Tab. Instead we want to replace
420      // the opaque type we previously inserted with the new concrete value. The
421      // refinement from the abstract (opaque) type to the new type causes all
422      // uses of the abstract type to use the concrete type (NewTy). This will
423      // also cause the opaque type to be deleted.
424      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
425
426      // This should have replaced the old opaque type with the new type in the
427      // value table... or with a preexisting type that was already in the
428      // system.  Let's just make sure it did.
429      assert(TypeList[NumRecords-1].get() != OldTy &&
430             "refineAbstractType didn't work!");
431    }
432  }
433}
434
435
436bool BitcodeReader::ParseTypeSymbolTable() {
437  if (Stream.EnterSubBlock(bitc::TYPE_SYMTAB_BLOCK_ID))
438    return Error("Malformed block record");
439
440  SmallVector<uint64_t, 64> Record;
441
442  // Read all the records for this type table.
443  std::string TypeName;
444  while (1) {
445    unsigned Code = Stream.ReadCode();
446    if (Code == bitc::END_BLOCK) {
447      if (Stream.ReadBlockEnd())
448        return Error("Error at end of type symbol table block");
449      return false;
450    }
451
452    if (Code == bitc::ENTER_SUBBLOCK) {
453      // No known subblocks, always skip them.
454      Stream.ReadSubBlockID();
455      if (Stream.SkipBlock())
456        return Error("Malformed block record");
457      continue;
458    }
459
460    if (Code == bitc::DEFINE_ABBREV) {
461      Stream.ReadAbbrevRecord();
462      continue;
463    }
464
465    // Read a record.
466    Record.clear();
467    switch (Stream.ReadRecord(Code, Record)) {
468    default:  // Default behavior: unknown type.
469      break;
470    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namechar x N]
471      if (ConvertToString(Record, 1, TypeName))
472        return Error("Invalid TST_ENTRY record");
473      unsigned TypeID = Record[0];
474      if (TypeID >= TypeList.size())
475        return Error("Invalid Type ID in TST_ENTRY record");
476
477      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
478      TypeName.clear();
479      break;
480    }
481  }
482}
483
484bool BitcodeReader::ParseValueSymbolTable() {
485  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
486    return Error("Malformed block record");
487
488  SmallVector<uint64_t, 64> Record;
489
490  // Read all the records for this value table.
491  SmallString<128> ValueName;
492  while (1) {
493    unsigned Code = Stream.ReadCode();
494    if (Code == bitc::END_BLOCK) {
495      if (Stream.ReadBlockEnd())
496        return Error("Error at end of value symbol table block");
497      return false;
498    }
499    if (Code == bitc::ENTER_SUBBLOCK) {
500      // No known subblocks, always skip them.
501      Stream.ReadSubBlockID();
502      if (Stream.SkipBlock())
503        return Error("Malformed block record");
504      continue;
505    }
506
507    if (Code == bitc::DEFINE_ABBREV) {
508      Stream.ReadAbbrevRecord();
509      continue;
510    }
511
512    // Read a record.
513    Record.clear();
514    switch (Stream.ReadRecord(Code, Record)) {
515    default:  // Default behavior: unknown type.
516      break;
517    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
518      if (ConvertToString(Record, 1, ValueName))
519        return Error("Invalid TST_ENTRY record");
520      unsigned ValueID = Record[0];
521      if (ValueID >= ValueList.size())
522        return Error("Invalid Value ID in VST_ENTRY record");
523      Value *V = ValueList[ValueID];
524
525      V->setName(&ValueName[0], ValueName.size());
526      ValueName.clear();
527      break;
528    }
529    case bitc::VST_CODE_BBENTRY: {
530      if (ConvertToString(Record, 1, ValueName))
531        return Error("Invalid VST_BBENTRY record");
532      BasicBlock *BB = getBasicBlock(Record[0]);
533      if (BB == 0)
534        return Error("Invalid BB ID in VST_BBENTRY record");
535
536      BB->setName(&ValueName[0], ValueName.size());
537      ValueName.clear();
538      break;
539    }
540    }
541  }
542}
543
544/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
545/// the LSB for dense VBR encoding.
546static uint64_t DecodeSignRotatedValue(uint64_t V) {
547  if ((V & 1) == 0)
548    return V >> 1;
549  if (V != 1)
550    return -(V >> 1);
551  // There is no such thing as -0 with integers.  "-0" really means MININT.
552  return 1ULL << 63;
553}
554
555/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
556/// values and aliases that we can.
557bool BitcodeReader::ResolveGlobalAndAliasInits() {
558  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
559  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
560
561  GlobalInitWorklist.swap(GlobalInits);
562  AliasInitWorklist.swap(AliasInits);
563
564  while (!GlobalInitWorklist.empty()) {
565    unsigned ValID = GlobalInitWorklist.back().second;
566    if (ValID >= ValueList.size()) {
567      // Not ready to resolve this yet, it requires something later in the file.
568      GlobalInits.push_back(GlobalInitWorklist.back());
569    } else {
570      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
571        GlobalInitWorklist.back().first->setInitializer(C);
572      else
573        return Error("Global variable initializer is not a constant!");
574    }
575    GlobalInitWorklist.pop_back();
576  }
577
578  while (!AliasInitWorklist.empty()) {
579    unsigned ValID = AliasInitWorklist.back().second;
580    if (ValID >= ValueList.size()) {
581      AliasInits.push_back(AliasInitWorklist.back());
582    } else {
583      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
584        AliasInitWorklist.back().first->setAliasee(C);
585      else
586        return Error("Alias initializer is not a constant!");
587    }
588    AliasInitWorklist.pop_back();
589  }
590  return false;
591}
592
593
594bool BitcodeReader::ParseConstants() {
595  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
596    return Error("Malformed block record");
597
598  SmallVector<uint64_t, 64> Record;
599
600  // Read all the records for this value table.
601  const Type *CurTy = Type::Int32Ty;
602  unsigned NextCstNo = ValueList.size();
603  while (1) {
604    unsigned Code = Stream.ReadCode();
605    if (Code == bitc::END_BLOCK) {
606      if (NextCstNo != ValueList.size())
607        return Error("Invalid constant reference!");
608
609      if (Stream.ReadBlockEnd())
610        return Error("Error at end of constants block");
611      return false;
612    }
613
614    if (Code == bitc::ENTER_SUBBLOCK) {
615      // No known subblocks, always skip them.
616      Stream.ReadSubBlockID();
617      if (Stream.SkipBlock())
618        return Error("Malformed block record");
619      continue;
620    }
621
622    if (Code == bitc::DEFINE_ABBREV) {
623      Stream.ReadAbbrevRecord();
624      continue;
625    }
626
627    // Read a record.
628    Record.clear();
629    Value *V = 0;
630    switch (Stream.ReadRecord(Code, Record)) {
631    default:  // Default behavior: unknown constant
632    case bitc::CST_CODE_UNDEF:     // UNDEF
633      V = UndefValue::get(CurTy);
634      break;
635    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
636      if (Record.empty())
637        return Error("Malformed CST_SETTYPE record");
638      if (Record[0] >= TypeList.size())
639        return Error("Invalid Type ID in CST_SETTYPE record");
640      CurTy = TypeList[Record[0]];
641      continue;  // Skip the ValueList manipulation.
642    case bitc::CST_CODE_NULL:      // NULL
643      V = Constant::getNullValue(CurTy);
644      break;
645    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
646      if (!isa<IntegerType>(CurTy) || Record.empty())
647        return Error("Invalid CST_INTEGER record");
648      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
649      break;
650    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
651      if (!isa<IntegerType>(CurTy) || Record.empty())
652        return Error("Invalid WIDE_INTEGER record");
653
654      unsigned NumWords = Record.size();
655      SmallVector<uint64_t, 8> Words;
656      Words.resize(NumWords);
657      for (unsigned i = 0; i != NumWords; ++i)
658        Words[i] = DecodeSignRotatedValue(Record[i]);
659      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
660                                 NumWords, &Words[0]));
661      break;
662    }
663    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
664      if (Record.empty())
665        return Error("Invalid FLOAT record");
666      if (CurTy == Type::FloatTy)
667        V = ConstantFP::get(APFloat(APInt(32, (uint32_t)Record[0])));
668      else if (CurTy == Type::DoubleTy)
669        V = ConstantFP::get(APFloat(APInt(64, Record[0])));
670      else if (CurTy == Type::X86_FP80Ty)
671        V = ConstantFP::get(APFloat(APInt(80, 2, &Record[0])));
672      else if (CurTy == Type::FP128Ty)
673        V = ConstantFP::get(APFloat(APInt(128, 2, &Record[0]), true));
674      else if (CurTy == Type::PPC_FP128Ty)
675        V = ConstantFP::get(APFloat(APInt(128, 2, &Record[0])));
676      else
677        V = UndefValue::get(CurTy);
678      break;
679    }
680
681    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
682      if (Record.empty())
683        return Error("Invalid CST_AGGREGATE record");
684
685      unsigned Size = Record.size();
686      std::vector<Constant*> Elts;
687
688      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
689        for (unsigned i = 0; i != Size; ++i)
690          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
691                                                     STy->getElementType(i)));
692        V = ConstantStruct::get(STy, Elts);
693      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
694        const Type *EltTy = ATy->getElementType();
695        for (unsigned i = 0; i != Size; ++i)
696          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
697        V = ConstantArray::get(ATy, Elts);
698      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
699        const Type *EltTy = VTy->getElementType();
700        for (unsigned i = 0; i != Size; ++i)
701          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
702        V = ConstantVector::get(Elts);
703      } else {
704        V = UndefValue::get(CurTy);
705      }
706      break;
707    }
708    case bitc::CST_CODE_STRING: { // STRING: [values]
709      if (Record.empty())
710        return Error("Invalid CST_AGGREGATE record");
711
712      const ArrayType *ATy = cast<ArrayType>(CurTy);
713      const Type *EltTy = ATy->getElementType();
714
715      unsigned Size = Record.size();
716      std::vector<Constant*> Elts;
717      for (unsigned i = 0; i != Size; ++i)
718        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
719      V = ConstantArray::get(ATy, Elts);
720      break;
721    }
722    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
723      if (Record.empty())
724        return Error("Invalid CST_AGGREGATE record");
725
726      const ArrayType *ATy = cast<ArrayType>(CurTy);
727      const Type *EltTy = ATy->getElementType();
728
729      unsigned Size = Record.size();
730      std::vector<Constant*> Elts;
731      for (unsigned i = 0; i != Size; ++i)
732        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
733      Elts.push_back(Constant::getNullValue(EltTy));
734      V = ConstantArray::get(ATy, Elts);
735      break;
736    }
737    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
738      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
739      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
740      if (Opc < 0) {
741        V = UndefValue::get(CurTy);  // Unknown binop.
742      } else {
743        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
744        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
745        V = ConstantExpr::get(Opc, LHS, RHS);
746      }
747      break;
748    }
749    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
750      if (Record.size() < 3) return Error("Invalid CE_CAST record");
751      int Opc = GetDecodedCastOpcode(Record[0]);
752      if (Opc < 0) {
753        V = UndefValue::get(CurTy);  // Unknown cast.
754      } else {
755        const Type *OpTy = getTypeByID(Record[1]);
756        if (!OpTy) return Error("Invalid CE_CAST record");
757        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
758        V = ConstantExpr::getCast(Opc, Op, CurTy);
759      }
760      break;
761    }
762    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
763      if (Record.size() & 1) return Error("Invalid CE_GEP record");
764      SmallVector<Constant*, 16> Elts;
765      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
766        const Type *ElTy = getTypeByID(Record[i]);
767        if (!ElTy) return Error("Invalid CE_GEP record");
768        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
769      }
770      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
771      break;
772    }
773    case bitc::CST_CODE_CE_EXTRACTVAL: { // CE_EXTRACTVAL: [n x operands]
774      if (Record.size() & 1) return Error("Invalid CE_EXTRACTVAL record");
775      SmallVector<Constant*, 16> Elts;
776      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
777        const Type *ElTy = getTypeByID(Record[i]);
778        if (!ElTy) return Error("Invalid CE_EXTRACTVAL record");
779        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
780      }
781      V = ConstantExpr::getExtractValue(Elts[0], &Elts[1], Elts.size()-1);
782      break;
783    }
784    case bitc::CST_CODE_CE_INSERTVAL: { // CE_INSERTVAL: [n x operands]
785      if (Record.size() & 1) return Error("Invalid CE_INSERTVAL record");
786      SmallVector<Constant*, 16> Elts;
787      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
788        const Type *ElTy = getTypeByID(Record[i]);
789        if (!ElTy) return Error("Invalid CE_INSERTVAL record");
790        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
791      }
792      V = ConstantExpr::getInsertValue(Elts[0], Elts[1],
793                                       &Elts[2], Elts.size()-1);
794      break;
795    }
796    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
797      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
798      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
799                                                              Type::Int1Ty),
800                                  ValueList.getConstantFwdRef(Record[1],CurTy),
801                                  ValueList.getConstantFwdRef(Record[2],CurTy));
802      break;
803    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
804      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
805      const VectorType *OpTy =
806        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
807      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
808      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
809      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
810                                                  OpTy->getElementType());
811      V = ConstantExpr::getExtractElement(Op0, Op1);
812      break;
813    }
814    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
815      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
816      if (Record.size() < 3 || OpTy == 0)
817        return Error("Invalid CE_INSERTELT record");
818      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
819      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
820                                                  OpTy->getElementType());
821      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
822      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
823      break;
824    }
825    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
826      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
827      if (Record.size() < 3 || OpTy == 0)
828        return Error("Invalid CE_INSERTELT record");
829      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
830      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
831      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
832      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
833      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
834      break;
835    }
836    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
837      if (Record.size() < 4) return Error("Invalid CE_CMP record");
838      const Type *OpTy = getTypeByID(Record[0]);
839      if (OpTy == 0) return Error("Invalid CE_CMP record");
840      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
841      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
842
843      if (OpTy->isFloatingPoint())
844        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
845      else if (!isa<VectorType>(OpTy))
846        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
847      else if (OpTy->isFPOrFPVector())
848        V = ConstantExpr::getVFCmp(Record[3], Op0, Op1);
849      else
850        V = ConstantExpr::getVICmp(Record[3], Op0, Op1);
851      break;
852    }
853    case bitc::CST_CODE_INLINEASM: {
854      if (Record.size() < 2) return Error("Invalid INLINEASM record");
855      std::string AsmStr, ConstrStr;
856      bool HasSideEffects = Record[0];
857      unsigned AsmStrSize = Record[1];
858      if (2+AsmStrSize >= Record.size())
859        return Error("Invalid INLINEASM record");
860      unsigned ConstStrSize = Record[2+AsmStrSize];
861      if (3+AsmStrSize+ConstStrSize > Record.size())
862        return Error("Invalid INLINEASM record");
863
864      for (unsigned i = 0; i != AsmStrSize; ++i)
865        AsmStr += (char)Record[2+i];
866      for (unsigned i = 0; i != ConstStrSize; ++i)
867        ConstrStr += (char)Record[3+AsmStrSize+i];
868      const PointerType *PTy = cast<PointerType>(CurTy);
869      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
870                         AsmStr, ConstrStr, HasSideEffects);
871      break;
872    }
873    }
874
875    ValueList.AssignValue(V, NextCstNo);
876    ++NextCstNo;
877  }
878}
879
880/// RememberAndSkipFunctionBody - When we see the block for a function body,
881/// remember where it is and then skip it.  This lets us lazily deserialize the
882/// functions.
883bool BitcodeReader::RememberAndSkipFunctionBody() {
884  // Get the function we are talking about.
885  if (FunctionsWithBodies.empty())
886    return Error("Insufficient function protos");
887
888  Function *Fn = FunctionsWithBodies.back();
889  FunctionsWithBodies.pop_back();
890
891  // Save the current stream state.
892  uint64_t CurBit = Stream.GetCurrentBitNo();
893  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
894
895  // Set the functions linkage to GhostLinkage so we know it is lazily
896  // deserialized.
897  Fn->setLinkage(GlobalValue::GhostLinkage);
898
899  // Skip over the function block for now.
900  if (Stream.SkipBlock())
901    return Error("Malformed block record");
902  return false;
903}
904
905bool BitcodeReader::ParseModule(const std::string &ModuleID) {
906  // Reject multiple MODULE_BLOCK's in a single bitstream.
907  if (TheModule)
908    return Error("Multiple MODULE_BLOCKs in same stream");
909
910  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
911    return Error("Malformed block record");
912
913  // Otherwise, create the module.
914  TheModule = new Module(ModuleID);
915
916  SmallVector<uint64_t, 64> Record;
917  std::vector<std::string> SectionTable;
918  std::vector<std::string> CollectorTable;
919
920  // Read all the records for this module.
921  while (!Stream.AtEndOfStream()) {
922    unsigned Code = Stream.ReadCode();
923    if (Code == bitc::END_BLOCK) {
924      if (Stream.ReadBlockEnd())
925        return Error("Error at end of module block");
926
927      // Patch the initializers for globals and aliases up.
928      ResolveGlobalAndAliasInits();
929      if (!GlobalInits.empty() || !AliasInits.empty())
930        return Error("Malformed global initializer set");
931      if (!FunctionsWithBodies.empty())
932        return Error("Too few function bodies found");
933
934      // Look for intrinsic functions which need to be upgraded at some point
935      for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
936           FI != FE; ++FI) {
937        Function* NewFn;
938        if (UpgradeIntrinsicFunction(FI, NewFn))
939          UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
940      }
941
942      // Force deallocation of memory for these vectors to favor the client that
943      // want lazy deserialization.
944      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
945      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
946      std::vector<Function*>().swap(FunctionsWithBodies);
947      return false;
948    }
949
950    if (Code == bitc::ENTER_SUBBLOCK) {
951      switch (Stream.ReadSubBlockID()) {
952      default:  // Skip unknown content.
953        if (Stream.SkipBlock())
954          return Error("Malformed block record");
955        break;
956      case bitc::BLOCKINFO_BLOCK_ID:
957        if (Stream.ReadBlockInfoBlock())
958          return Error("Malformed BlockInfoBlock");
959        break;
960      case bitc::PARAMATTR_BLOCK_ID:
961        if (ParseParamAttrBlock())
962          return true;
963        break;
964      case bitc::TYPE_BLOCK_ID:
965        if (ParseTypeTable())
966          return true;
967        break;
968      case bitc::TYPE_SYMTAB_BLOCK_ID:
969        if (ParseTypeSymbolTable())
970          return true;
971        break;
972      case bitc::VALUE_SYMTAB_BLOCK_ID:
973        if (ParseValueSymbolTable())
974          return true;
975        break;
976      case bitc::CONSTANTS_BLOCK_ID:
977        if (ParseConstants() || ResolveGlobalAndAliasInits())
978          return true;
979        break;
980      case bitc::FUNCTION_BLOCK_ID:
981        // If this is the first function body we've seen, reverse the
982        // FunctionsWithBodies list.
983        if (!HasReversedFunctionsWithBodies) {
984          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
985          HasReversedFunctionsWithBodies = true;
986        }
987
988        if (RememberAndSkipFunctionBody())
989          return true;
990        break;
991      }
992      continue;
993    }
994
995    if (Code == bitc::DEFINE_ABBREV) {
996      Stream.ReadAbbrevRecord();
997      continue;
998    }
999
1000    // Read a record.
1001    switch (Stream.ReadRecord(Code, Record)) {
1002    default: break;  // Default behavior, ignore unknown content.
1003    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
1004      if (Record.size() < 1)
1005        return Error("Malformed MODULE_CODE_VERSION");
1006      // Only version #0 is supported so far.
1007      if (Record[0] != 0)
1008        return Error("Unknown bitstream version!");
1009      break;
1010    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1011      std::string S;
1012      if (ConvertToString(Record, 0, S))
1013        return Error("Invalid MODULE_CODE_TRIPLE record");
1014      TheModule->setTargetTriple(S);
1015      break;
1016    }
1017    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
1018      std::string S;
1019      if (ConvertToString(Record, 0, S))
1020        return Error("Invalid MODULE_CODE_DATALAYOUT record");
1021      TheModule->setDataLayout(S);
1022      break;
1023    }
1024    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
1025      std::string S;
1026      if (ConvertToString(Record, 0, S))
1027        return Error("Invalid MODULE_CODE_ASM record");
1028      TheModule->setModuleInlineAsm(S);
1029      break;
1030    }
1031    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
1032      std::string S;
1033      if (ConvertToString(Record, 0, S))
1034        return Error("Invalid MODULE_CODE_DEPLIB record");
1035      TheModule->addLibrary(S);
1036      break;
1037    }
1038    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
1039      std::string S;
1040      if (ConvertToString(Record, 0, S))
1041        return Error("Invalid MODULE_CODE_SECTIONNAME record");
1042      SectionTable.push_back(S);
1043      break;
1044    }
1045    case bitc::MODULE_CODE_COLLECTORNAME: {  // SECTIONNAME: [strchr x N]
1046      std::string S;
1047      if (ConvertToString(Record, 0, S))
1048        return Error("Invalid MODULE_CODE_COLLECTORNAME record");
1049      CollectorTable.push_back(S);
1050      break;
1051    }
1052    // GLOBALVAR: [pointer type, isconst, initid,
1053    //             linkage, alignment, section, visibility, threadlocal]
1054    case bitc::MODULE_CODE_GLOBALVAR: {
1055      if (Record.size() < 6)
1056        return Error("Invalid MODULE_CODE_GLOBALVAR record");
1057      const Type *Ty = getTypeByID(Record[0]);
1058      if (!isa<PointerType>(Ty))
1059        return Error("Global not a pointer type!");
1060      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
1061      Ty = cast<PointerType>(Ty)->getElementType();
1062
1063      bool isConstant = Record[1];
1064      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1065      unsigned Alignment = (1 << Record[4]) >> 1;
1066      std::string Section;
1067      if (Record[5]) {
1068        if (Record[5]-1 >= SectionTable.size())
1069          return Error("Invalid section ID");
1070        Section = SectionTable[Record[5]-1];
1071      }
1072      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1073      if (Record.size() > 6)
1074        Visibility = GetDecodedVisibility(Record[6]);
1075      bool isThreadLocal = false;
1076      if (Record.size() > 7)
1077        isThreadLocal = Record[7];
1078
1079      GlobalVariable *NewGV =
1080        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule,
1081                           isThreadLocal, AddressSpace);
1082      NewGV->setAlignment(Alignment);
1083      if (!Section.empty())
1084        NewGV->setSection(Section);
1085      NewGV->setVisibility(Visibility);
1086      NewGV->setThreadLocal(isThreadLocal);
1087
1088      ValueList.push_back(NewGV);
1089
1090      // Remember which value to use for the global initializer.
1091      if (unsigned InitID = Record[2])
1092        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1093      break;
1094    }
1095    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1096    //             alignment, section, visibility, collector]
1097    case bitc::MODULE_CODE_FUNCTION: {
1098      if (Record.size() < 8)
1099        return Error("Invalid MODULE_CODE_FUNCTION record");
1100      const Type *Ty = getTypeByID(Record[0]);
1101      if (!isa<PointerType>(Ty))
1102        return Error("Function not a pointer type!");
1103      const FunctionType *FTy =
1104        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1105      if (!FTy)
1106        return Error("Function not a pointer to function type!");
1107
1108      Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
1109                                        "", TheModule);
1110
1111      Func->setCallingConv(Record[1]);
1112      bool isProto = Record[2];
1113      Func->setLinkage(GetDecodedLinkage(Record[3]));
1114      Func->setParamAttrs(getParamAttrs(Record[4]));
1115
1116      Func->setAlignment((1 << Record[5]) >> 1);
1117      if (Record[6]) {
1118        if (Record[6]-1 >= SectionTable.size())
1119          return Error("Invalid section ID");
1120        Func->setSection(SectionTable[Record[6]-1]);
1121      }
1122      Func->setVisibility(GetDecodedVisibility(Record[7]));
1123      if (Record.size() > 8 && Record[8]) {
1124        if (Record[8]-1 > CollectorTable.size())
1125          return Error("Invalid collector ID");
1126        Func->setCollector(CollectorTable[Record[8]-1].c_str());
1127      }
1128
1129      ValueList.push_back(Func);
1130
1131      // If this is a function with a body, remember the prototype we are
1132      // creating now, so that we can match up the body with them later.
1133      if (!isProto)
1134        FunctionsWithBodies.push_back(Func);
1135      break;
1136    }
1137    // ALIAS: [alias type, aliasee val#, linkage]
1138    // ALIAS: [alias type, aliasee val#, linkage, visibility]
1139    case bitc::MODULE_CODE_ALIAS: {
1140      if (Record.size() < 3)
1141        return Error("Invalid MODULE_ALIAS record");
1142      const Type *Ty = getTypeByID(Record[0]);
1143      if (!isa<PointerType>(Ty))
1144        return Error("Function not a pointer type!");
1145
1146      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1147                                           "", 0, TheModule);
1148      // Old bitcode files didn't have visibility field.
1149      if (Record.size() > 3)
1150        NewGA->setVisibility(GetDecodedVisibility(Record[3]));
1151      ValueList.push_back(NewGA);
1152      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1153      break;
1154    }
1155    /// MODULE_CODE_PURGEVALS: [numvals]
1156    case bitc::MODULE_CODE_PURGEVALS:
1157      // Trim down the value list to the specified size.
1158      if (Record.size() < 1 || Record[0] > ValueList.size())
1159        return Error("Invalid MODULE_PURGEVALS record");
1160      ValueList.shrinkTo(Record[0]);
1161      break;
1162    }
1163    Record.clear();
1164  }
1165
1166  return Error("Premature end of bitstream");
1167}
1168
1169
1170bool BitcodeReader::ParseBitcode() {
1171  TheModule = 0;
1172
1173  if (Buffer->getBufferSize() & 3)
1174    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1175
1176  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1177  Stream.init(BufPtr, BufPtr+Buffer->getBufferSize());
1178
1179  // Sniff for the signature.
1180  if (Stream.Read(8) != 'B' ||
1181      Stream.Read(8) != 'C' ||
1182      Stream.Read(4) != 0x0 ||
1183      Stream.Read(4) != 0xC ||
1184      Stream.Read(4) != 0xE ||
1185      Stream.Read(4) != 0xD)
1186    return Error("Invalid bitcode signature");
1187
1188  // We expect a number of well-defined blocks, though we don't necessarily
1189  // need to understand them all.
1190  while (!Stream.AtEndOfStream()) {
1191    unsigned Code = Stream.ReadCode();
1192
1193    if (Code != bitc::ENTER_SUBBLOCK)
1194      return Error("Invalid record at top-level");
1195
1196    unsigned BlockID = Stream.ReadSubBlockID();
1197
1198    // We only know the MODULE subblock ID.
1199    switch (BlockID) {
1200    case bitc::BLOCKINFO_BLOCK_ID:
1201      if (Stream.ReadBlockInfoBlock())
1202        return Error("Malformed BlockInfoBlock");
1203      break;
1204    case bitc::MODULE_BLOCK_ID:
1205      if (ParseModule(Buffer->getBufferIdentifier()))
1206        return true;
1207      break;
1208    default:
1209      if (Stream.SkipBlock())
1210        return Error("Malformed block record");
1211      break;
1212    }
1213  }
1214
1215  return false;
1216}
1217
1218
1219/// ParseFunctionBody - Lazily parse the specified function body block.
1220bool BitcodeReader::ParseFunctionBody(Function *F) {
1221  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1222    return Error("Malformed block record");
1223
1224  unsigned ModuleValueListSize = ValueList.size();
1225
1226  // Add all the function arguments to the value table.
1227  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1228    ValueList.push_back(I);
1229
1230  unsigned NextValueNo = ValueList.size();
1231  BasicBlock *CurBB = 0;
1232  unsigned CurBBNo = 0;
1233
1234  // Read all the records.
1235  SmallVector<uint64_t, 64> Record;
1236  while (1) {
1237    unsigned Code = Stream.ReadCode();
1238    if (Code == bitc::END_BLOCK) {
1239      if (Stream.ReadBlockEnd())
1240        return Error("Error at end of function block");
1241      break;
1242    }
1243
1244    if (Code == bitc::ENTER_SUBBLOCK) {
1245      switch (Stream.ReadSubBlockID()) {
1246      default:  // Skip unknown content.
1247        if (Stream.SkipBlock())
1248          return Error("Malformed block record");
1249        break;
1250      case bitc::CONSTANTS_BLOCK_ID:
1251        if (ParseConstants()) return true;
1252        NextValueNo = ValueList.size();
1253        break;
1254      case bitc::VALUE_SYMTAB_BLOCK_ID:
1255        if (ParseValueSymbolTable()) return true;
1256        break;
1257      }
1258      continue;
1259    }
1260
1261    if (Code == bitc::DEFINE_ABBREV) {
1262      Stream.ReadAbbrevRecord();
1263      continue;
1264    }
1265
1266    // Read a record.
1267    Record.clear();
1268    Instruction *I = 0;
1269    switch (Stream.ReadRecord(Code, Record)) {
1270    default: // Default behavior: reject
1271      return Error("Unknown instruction");
1272    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1273      if (Record.size() < 1 || Record[0] == 0)
1274        return Error("Invalid DECLAREBLOCKS record");
1275      // Create all the basic blocks for the function.
1276      FunctionBBs.resize(Record[0]);
1277      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1278        FunctionBBs[i] = BasicBlock::Create("", F);
1279      CurBB = FunctionBBs[0];
1280      continue;
1281
1282    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1283      unsigned OpNum = 0;
1284      Value *LHS, *RHS;
1285      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1286          getValue(Record, OpNum, LHS->getType(), RHS) ||
1287          OpNum+1 != Record.size())
1288        return Error("Invalid BINOP record");
1289
1290      int Opc = GetDecodedBinaryOpcode(Record[OpNum], LHS->getType());
1291      if (Opc == -1) return Error("Invalid BINOP record");
1292      I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
1293      break;
1294    }
1295    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
1296      unsigned OpNum = 0;
1297      Value *Op;
1298      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1299          OpNum+2 != Record.size())
1300        return Error("Invalid CAST record");
1301
1302      const Type *ResTy = getTypeByID(Record[OpNum]);
1303      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
1304      if (Opc == -1 || ResTy == 0)
1305        return Error("Invalid CAST record");
1306      I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
1307      break;
1308    }
1309    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
1310      unsigned OpNum = 0;
1311      Value *BasePtr;
1312      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
1313        return Error("Invalid GEP record");
1314
1315      SmallVector<Value*, 16> GEPIdx;
1316      while (OpNum != Record.size()) {
1317        Value *Op;
1318        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1319          return Error("Invalid GEP record");
1320        GEPIdx.push_back(Op);
1321      }
1322
1323      I = GetElementPtrInst::Create(BasePtr, GEPIdx.begin(), GEPIdx.end());
1324      break;
1325    }
1326
1327    case bitc::FUNC_CODE_INST_EXTRACTVAL: { // EXTRACTVAL: [n x operands]
1328      unsigned OpNum = 0;
1329      Value *Agg;
1330      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
1331        return Error("Invalid EXTRACTVAL record");
1332
1333      SmallVector<Value*, 16> EXTRACTVALIdx;
1334      while (OpNum != Record.size()) {
1335        Value *Op;
1336        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1337          return Error("Invalid EXTRACTVAL record");
1338        EXTRACTVALIdx.push_back(Op);
1339      }
1340
1341      I = ExtractValueInst::Create(Agg,
1342                                   EXTRACTVALIdx.begin(), EXTRACTVALIdx.end());
1343      break;
1344    }
1345
1346    case bitc::FUNC_CODE_INST_INSERTVAL: { // INSERTVAL: [n x operands]
1347      unsigned OpNum = 0;
1348      Value *Agg;
1349      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
1350        return Error("Invalid INSERTVAL record");
1351      Value *Val;
1352      if (getValueTypePair(Record, OpNum, NextValueNo, Val))
1353        return Error("Invalid INSERTVAL record");
1354
1355      SmallVector<Value*, 16> INSERTVALIdx;
1356      while (OpNum != Record.size()) {
1357        Value *Op;
1358        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1359          return Error("Invalid INSERTVAL record");
1360        INSERTVALIdx.push_back(Op);
1361      }
1362
1363      I = InsertValueInst::Create(Agg, Val,
1364                                  INSERTVALIdx.begin(), INSERTVALIdx.end());
1365      break;
1366    }
1367
1368    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
1369      unsigned OpNum = 0;
1370      Value *TrueVal, *FalseVal, *Cond;
1371      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
1372          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
1373          getValue(Record, OpNum, Type::Int1Ty, Cond))
1374        return Error("Invalid SELECT record");
1375
1376      I = SelectInst::Create(Cond, TrueVal, FalseVal);
1377      break;
1378    }
1379
1380    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1381      unsigned OpNum = 0;
1382      Value *Vec, *Idx;
1383      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1384          getValue(Record, OpNum, Type::Int32Ty, Idx))
1385        return Error("Invalid EXTRACTELT record");
1386      I = new ExtractElementInst(Vec, Idx);
1387      break;
1388    }
1389
1390    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1391      unsigned OpNum = 0;
1392      Value *Vec, *Elt, *Idx;
1393      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1394          getValue(Record, OpNum,
1395                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
1396          getValue(Record, OpNum, Type::Int32Ty, Idx))
1397        return Error("Invalid INSERTELT record");
1398      I = InsertElementInst::Create(Vec, Elt, Idx);
1399      break;
1400    }
1401
1402    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
1403      unsigned OpNum = 0;
1404      Value *Vec1, *Vec2, *Mask;
1405      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
1406          getValue(Record, OpNum, Vec1->getType(), Vec2))
1407        return Error("Invalid SHUFFLEVEC record");
1408
1409      const Type *MaskTy =
1410        VectorType::get(Type::Int32Ty,
1411                        cast<VectorType>(Vec1->getType())->getNumElements());
1412
1413      if (getValue(Record, OpNum, MaskTy, Mask))
1414        return Error("Invalid SHUFFLEVEC record");
1415      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1416      break;
1417    }
1418
1419    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1420      unsigned OpNum = 0;
1421      Value *LHS, *RHS;
1422      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1423          getValue(Record, OpNum, LHS->getType(), RHS) ||
1424          OpNum+1 != Record.size())
1425        return Error("Invalid CMP record");
1426
1427      if (LHS->getType()->isFloatingPoint())
1428        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1429      else if (!isa<VectorType>(LHS->getType()))
1430        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1431      else if (LHS->getType()->isFPOrFPVector())
1432        I = new VFCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1433      else
1434        I = new VICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1435      break;
1436    }
1437    case bitc::FUNC_CODE_INST_GETRESULT: { // GETRESULT: [ty, val, n]
1438      if (Record.size() != 2)
1439        return Error("Invalid GETRESULT record");
1440      unsigned OpNum = 0;
1441      Value *Op;
1442      getValueTypePair(Record, OpNum, NextValueNo, Op);
1443      unsigned Index = Record[1];
1444      I = new GetResultInst(Op, Index);
1445      break;
1446    }
1447
1448    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1449      {
1450        unsigned Size = Record.size();
1451        if (Size == 0) {
1452          I = ReturnInst::Create();
1453          break;
1454        } else {
1455          unsigned OpNum = 0;
1456          SmallVector<Value *,4> Vs;
1457          do {
1458            Value *Op = NULL;
1459            if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1460              return Error("Invalid RET record");
1461            Vs.push_back(Op);
1462          } while(OpNum != Record.size());
1463
1464          // SmallVector Vs has at least one element.
1465          I = ReturnInst::Create(&Vs[0], Vs.size());
1466          break;
1467        }
1468      }
1469    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1470      if (Record.size() != 1 && Record.size() != 3)
1471        return Error("Invalid BR record");
1472      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1473      if (TrueDest == 0)
1474        return Error("Invalid BR record");
1475
1476      if (Record.size() == 1)
1477        I = BranchInst::Create(TrueDest);
1478      else {
1479        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1480        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1481        if (FalseDest == 0 || Cond == 0)
1482          return Error("Invalid BR record");
1483        I = BranchInst::Create(TrueDest, FalseDest, Cond);
1484      }
1485      break;
1486    }
1487    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1488      if (Record.size() < 3 || (Record.size() & 1) == 0)
1489        return Error("Invalid SWITCH record");
1490      const Type *OpTy = getTypeByID(Record[0]);
1491      Value *Cond = getFnValueByID(Record[1], OpTy);
1492      BasicBlock *Default = getBasicBlock(Record[2]);
1493      if (OpTy == 0 || Cond == 0 || Default == 0)
1494        return Error("Invalid SWITCH record");
1495      unsigned NumCases = (Record.size()-3)/2;
1496      SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
1497      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1498        ConstantInt *CaseVal =
1499          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1500        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1501        if (CaseVal == 0 || DestBB == 0) {
1502          delete SI;
1503          return Error("Invalid SWITCH record!");
1504        }
1505        SI->addCase(CaseVal, DestBB);
1506      }
1507      I = SI;
1508      break;
1509    }
1510
1511    case bitc::FUNC_CODE_INST_INVOKE: {
1512      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
1513      if (Record.size() < 4) return Error("Invalid INVOKE record");
1514      PAListPtr PAL = getParamAttrs(Record[0]);
1515      unsigned CCInfo = Record[1];
1516      BasicBlock *NormalBB = getBasicBlock(Record[2]);
1517      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
1518
1519      unsigned OpNum = 4;
1520      Value *Callee;
1521      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1522        return Error("Invalid INVOKE record");
1523
1524      const PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
1525      const FunctionType *FTy = !CalleeTy ? 0 :
1526        dyn_cast<FunctionType>(CalleeTy->getElementType());
1527
1528      // Check that the right number of fixed parameters are here.
1529      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
1530          Record.size() < OpNum+FTy->getNumParams())
1531        return Error("Invalid INVOKE record");
1532
1533      SmallVector<Value*, 16> Ops;
1534      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1535        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1536        if (Ops.back() == 0) return Error("Invalid INVOKE record");
1537      }
1538
1539      if (!FTy->isVarArg()) {
1540        if (Record.size() != OpNum)
1541          return Error("Invalid INVOKE record");
1542      } else {
1543        // Read type/value pairs for varargs params.
1544        while (OpNum != Record.size()) {
1545          Value *Op;
1546          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1547            return Error("Invalid INVOKE record");
1548          Ops.push_back(Op);
1549        }
1550      }
1551
1552      I = InvokeInst::Create(Callee, NormalBB, UnwindBB,
1553                             Ops.begin(), Ops.end());
1554      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1555      cast<InvokeInst>(I)->setParamAttrs(PAL);
1556      break;
1557    }
1558    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1559      I = new UnwindInst();
1560      break;
1561    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1562      I = new UnreachableInst();
1563      break;
1564    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
1565      if (Record.size() < 1 || ((Record.size()-1)&1))
1566        return Error("Invalid PHI record");
1567      const Type *Ty = getTypeByID(Record[0]);
1568      if (!Ty) return Error("Invalid PHI record");
1569
1570      PHINode *PN = PHINode::Create(Ty);
1571      PN->reserveOperandSpace((Record.size()-1)/2);
1572
1573      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
1574        Value *V = getFnValueByID(Record[1+i], Ty);
1575        BasicBlock *BB = getBasicBlock(Record[2+i]);
1576        if (!V || !BB) return Error("Invalid PHI record");
1577        PN->addIncoming(V, BB);
1578      }
1579      I = PN;
1580      break;
1581    }
1582
1583    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1584      if (Record.size() < 3)
1585        return Error("Invalid MALLOC record");
1586      const PointerType *Ty =
1587        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1588      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1589      unsigned Align = Record[2];
1590      if (!Ty || !Size) return Error("Invalid MALLOC record");
1591      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1592      break;
1593    }
1594    case bitc::FUNC_CODE_INST_FREE: { // FREE: [op, opty]
1595      unsigned OpNum = 0;
1596      Value *Op;
1597      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1598          OpNum != Record.size())
1599        return Error("Invalid FREE record");
1600      I = new FreeInst(Op);
1601      break;
1602    }
1603    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1604      if (Record.size() < 3)
1605        return Error("Invalid ALLOCA record");
1606      const PointerType *Ty =
1607        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1608      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1609      unsigned Align = Record[2];
1610      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1611      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1612      break;
1613    }
1614    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1615      unsigned OpNum = 0;
1616      Value *Op;
1617      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1618          OpNum+2 != Record.size())
1619        return Error("Invalid LOAD record");
1620
1621      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1622      break;
1623    }
1624    case bitc::FUNC_CODE_INST_STORE2: { // STORE2:[ptrty, ptr, val, align, vol]
1625      unsigned OpNum = 0;
1626      Value *Val, *Ptr;
1627      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
1628          getValue(Record, OpNum,
1629                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
1630          OpNum+2 != Record.size())
1631        return Error("Invalid STORE record");
1632
1633      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1634      break;
1635    }
1636    case bitc::FUNC_CODE_INST_STORE: { // STORE:[val, valty, ptr, align, vol]
1637      // FIXME: Legacy form of store instruction. Should be removed in LLVM 3.0.
1638      unsigned OpNum = 0;
1639      Value *Val, *Ptr;
1640      if (getValueTypePair(Record, OpNum, NextValueNo, Val) ||
1641          getValue(Record, OpNum, PointerType::getUnqual(Val->getType()), Ptr)||
1642          OpNum+2 != Record.size())
1643        return Error("Invalid STORE record");
1644
1645      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1646      break;
1647    }
1648    case bitc::FUNC_CODE_INST_CALL: {
1649      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
1650      if (Record.size() < 3)
1651        return Error("Invalid CALL record");
1652
1653      PAListPtr PAL = getParamAttrs(Record[0]);
1654      unsigned CCInfo = Record[1];
1655
1656      unsigned OpNum = 2;
1657      Value *Callee;
1658      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1659        return Error("Invalid CALL record");
1660
1661      const PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
1662      const FunctionType *FTy = 0;
1663      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1664      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
1665        return Error("Invalid CALL record");
1666
1667      SmallVector<Value*, 16> Args;
1668      // Read the fixed params.
1669      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1670        if (FTy->getParamType(i)->getTypeID()==Type::LabelTyID)
1671          Args.push_back(getBasicBlock(Record[OpNum]));
1672        else
1673          Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1674        if (Args.back() == 0) return Error("Invalid CALL record");
1675      }
1676
1677      // Read type/value pairs for varargs params.
1678      if (!FTy->isVarArg()) {
1679        if (OpNum != Record.size())
1680          return Error("Invalid CALL record");
1681      } else {
1682        while (OpNum != Record.size()) {
1683          Value *Op;
1684          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1685            return Error("Invalid CALL record");
1686          Args.push_back(Op);
1687        }
1688      }
1689
1690      I = CallInst::Create(Callee, Args.begin(), Args.end());
1691      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1692      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1693      cast<CallInst>(I)->setParamAttrs(PAL);
1694      break;
1695    }
1696    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1697      if (Record.size() < 3)
1698        return Error("Invalid VAARG record");
1699      const Type *OpTy = getTypeByID(Record[0]);
1700      Value *Op = getFnValueByID(Record[1], OpTy);
1701      const Type *ResTy = getTypeByID(Record[2]);
1702      if (!OpTy || !Op || !ResTy)
1703        return Error("Invalid VAARG record");
1704      I = new VAArgInst(Op, ResTy);
1705      break;
1706    }
1707    }
1708
1709    // Add instruction to end of current BB.  If there is no current BB, reject
1710    // this file.
1711    if (CurBB == 0) {
1712      delete I;
1713      return Error("Invalid instruction with no BB");
1714    }
1715    CurBB->getInstList().push_back(I);
1716
1717    // If this was a terminator instruction, move to the next block.
1718    if (isa<TerminatorInst>(I)) {
1719      ++CurBBNo;
1720      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1721    }
1722
1723    // Non-void values get registered in the value table for future use.
1724    if (I && I->getType() != Type::VoidTy)
1725      ValueList.AssignValue(I, NextValueNo++);
1726  }
1727
1728  // Check the function list for unresolved values.
1729  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1730    if (A->getParent() == 0) {
1731      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1732      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1733        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1734          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1735          delete A;
1736        }
1737      }
1738      return Error("Never resolved value found in function!");
1739    }
1740  }
1741
1742  // Trim the value list down to the size it was before we parsed this function.
1743  ValueList.shrinkTo(ModuleValueListSize);
1744  std::vector<BasicBlock*>().swap(FunctionBBs);
1745
1746  return false;
1747}
1748
1749//===----------------------------------------------------------------------===//
1750// ModuleProvider implementation
1751//===----------------------------------------------------------------------===//
1752
1753
1754bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1755  // If it already is material, ignore the request.
1756  if (!F->hasNotBeenReadFromBitcode()) return false;
1757
1758  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1759    DeferredFunctionInfo.find(F);
1760  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1761
1762  // Move the bit stream to the saved position of the deferred function body and
1763  // restore the real linkage type for the function.
1764  Stream.JumpToBit(DFII->second.first);
1765  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1766
1767  if (ParseFunctionBody(F)) {
1768    if (ErrInfo) *ErrInfo = ErrorString;
1769    return true;
1770  }
1771
1772  // Upgrade any old intrinsic calls in the function.
1773  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
1774       E = UpgradedIntrinsics.end(); I != E; ++I) {
1775    if (I->first != I->second) {
1776      for (Value::use_iterator UI = I->first->use_begin(),
1777           UE = I->first->use_end(); UI != UE; ) {
1778        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1779          UpgradeIntrinsicCall(CI, I->second);
1780      }
1781    }
1782  }
1783
1784  return false;
1785}
1786
1787void BitcodeReader::dematerializeFunction(Function *F) {
1788  // If this function isn't materialized, or if it is a proto, this is a noop.
1789  if (F->hasNotBeenReadFromBitcode() || F->isDeclaration())
1790    return;
1791
1792  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
1793
1794  // Just forget the function body, we can remat it later.
1795  F->deleteBody();
1796  F->setLinkage(GlobalValue::GhostLinkage);
1797}
1798
1799
1800Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
1801  for (DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1802       DeferredFunctionInfo.begin(), E = DeferredFunctionInfo.end(); I != E;
1803       ++I) {
1804    Function *F = I->first;
1805    if (F->hasNotBeenReadFromBitcode() &&
1806        materializeFunction(F, ErrInfo))
1807      return 0;
1808  }
1809
1810  // Upgrade any intrinsic calls that slipped through (should not happen!) and
1811  // delete the old functions to clean up. We can't do this unless the entire
1812  // module is materialized because there could always be another function body
1813  // with calls to the old function.
1814  for (std::vector<std::pair<Function*, Function*> >::iterator I =
1815       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
1816    if (I->first != I->second) {
1817      for (Value::use_iterator UI = I->first->use_begin(),
1818           UE = I->first->use_end(); UI != UE; ) {
1819        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1820          UpgradeIntrinsicCall(CI, I->second);
1821      }
1822      ValueList.replaceUsesOfWith(I->first, I->second);
1823      I->first->eraseFromParent();
1824    }
1825  }
1826  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
1827
1828  return TheModule;
1829}
1830
1831
1832/// This method is provided by the parent ModuleProvde class and overriden
1833/// here. It simply releases the module from its provided and frees up our
1834/// state.
1835/// @brief Release our hold on the generated module
1836Module *BitcodeReader::releaseModule(std::string *ErrInfo) {
1837  // Since we're losing control of this Module, we must hand it back complete
1838  Module *M = ModuleProvider::releaseModule(ErrInfo);
1839  FreeState();
1840  return M;
1841}
1842
1843
1844//===----------------------------------------------------------------------===//
1845// External interface
1846//===----------------------------------------------------------------------===//
1847
1848/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1849///
1850ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1851                                               std::string *ErrMsg) {
1852  BitcodeReader *R = new BitcodeReader(Buffer);
1853  if (R->ParseBitcode()) {
1854    if (ErrMsg)
1855      *ErrMsg = R->getErrorString();
1856
1857    // Don't let the BitcodeReader dtor delete 'Buffer'.
1858    R->releaseMemoryBuffer();
1859    delete R;
1860    return 0;
1861  }
1862  return R;
1863}
1864
1865/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
1866/// If an error occurs, return null and fill in *ErrMsg if non-null.
1867Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
1868  BitcodeReader *R;
1869  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
1870  if (!R) return 0;
1871
1872  // Read in the entire module.
1873  Module *M = R->materializeModule(ErrMsg);
1874
1875  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
1876  // there was an error.
1877  R->releaseMemoryBuffer();
1878
1879  // If there was no error, tell ModuleProvider not to delete it when its dtor
1880  // is run.
1881  if (M)
1882    M = R->releaseModule(ErrMsg);
1883
1884  delete R;
1885  return M;
1886}
1887