BitcodeReader.cpp revision 6fa6a32e4e2fdbb77c82fd7f64a7232cdcac994e 
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] = C;
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] = V;
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: {
774                                    // CE_EXTRACTVAL: [opty, opval, n x indices]
775      const Type *AggTy = getTypeByID(Record[0]);
776      if (!AggTy || !AggTy->isAggregateType())
777        return Error("Invalid CE_EXTRACTVAL record");
778      Constant *Agg = ValueList.getConstantFwdRef(Record[1], AggTy);
779      SmallVector<unsigned, 4> Indices;
780      for (unsigned i = 2, e = Record.size(); i != e; ++i) {
781        uint64_t Index = Record[i];
782        if ((unsigned)Index != Index)
783          return Error("Invalid CE_EXTRACTVAL record");
784        Indices.push_back((unsigned)Index);
785      }
786      if (!ExtractValueInst::getIndexedType(AggTy,
787                                            Indices.begin(), Indices.end()))
788        return Error("Invalid CE_EXTRACTVAL record");
789      V = ConstantExpr::getExtractValue(Agg, &Indices[0], Indices.size());
790      break;
791    }
792    case bitc::CST_CODE_CE_INSERTVAL: {
793                        // CE_INSERTVAL: [opty, opval, opty, opval, n x indices]
794      const Type *AggTy = getTypeByID(Record[0]);
795      if (!AggTy || !AggTy->isAggregateType())
796        return Error("Invalid CE_INSERTVAL record");
797      Constant *Agg = ValueList.getConstantFwdRef(Record[1], AggTy);
798      const Type *ValTy = getTypeByID(Record[2]);
799      Constant *Val = ValueList.getConstantFwdRef(Record[3], ValTy);
800      SmallVector<unsigned, 4> Indices;
801      for (unsigned i = 4, e = Record.size(); i != e; ++i) {
802        uint64_t Index = Record[i];
803        if ((unsigned)Index != Index)
804          return Error("Invalid CE_INSERTVAL record");
805        Indices.push_back((unsigned)Index);
806      }
807      if (ExtractValueInst::getIndexedType(AggTy,
808                                           Indices.begin(),
809                                           Indices.end()) != ValTy)
810        return Error("Invalid CE_INSERTVAL record");
811      V = ConstantExpr::getInsertValue(Agg, Val, &Indices[0], Indices.size());
812      break;
813    }
814    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
815      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
816      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
817                                                              Type::Int1Ty),
818                                  ValueList.getConstantFwdRef(Record[1],CurTy),
819                                  ValueList.getConstantFwdRef(Record[2],CurTy));
820      break;
821    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
822      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
823      const VectorType *OpTy =
824        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
825      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
826      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
827      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
828                                                  OpTy->getElementType());
829      V = ConstantExpr::getExtractElement(Op0, Op1);
830      break;
831    }
832    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
833      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
834      if (Record.size() < 3 || OpTy == 0)
835        return Error("Invalid CE_INSERTELT record");
836      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
837      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
838                                                  OpTy->getElementType());
839      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
840      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
841      break;
842    }
843    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
844      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
845      if (Record.size() < 3 || OpTy == 0)
846        return Error("Invalid CE_INSERTELT record");
847      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
848      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
849      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
850      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
851      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
852      break;
853    }
854    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
855      if (Record.size() < 4) return Error("Invalid CE_CMP record");
856      const Type *OpTy = getTypeByID(Record[0]);
857      if (OpTy == 0) return Error("Invalid CE_CMP record");
858      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
859      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
860
861      if (OpTy->isFloatingPoint())
862        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
863      else if (!isa<VectorType>(OpTy))
864        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
865      else if (OpTy->isFPOrFPVector())
866        V = ConstantExpr::getVFCmp(Record[3], Op0, Op1);
867      else
868        V = ConstantExpr::getVICmp(Record[3], Op0, Op1);
869      break;
870    }
871    case bitc::CST_CODE_INLINEASM: {
872      if (Record.size() < 2) return Error("Invalid INLINEASM record");
873      std::string AsmStr, ConstrStr;
874      bool HasSideEffects = Record[0];
875      unsigned AsmStrSize = Record[1];
876      if (2+AsmStrSize >= Record.size())
877        return Error("Invalid INLINEASM record");
878      unsigned ConstStrSize = Record[2+AsmStrSize];
879      if (3+AsmStrSize+ConstStrSize > Record.size())
880        return Error("Invalid INLINEASM record");
881
882      for (unsigned i = 0; i != AsmStrSize; ++i)
883        AsmStr += (char)Record[2+i];
884      for (unsigned i = 0; i != ConstStrSize; ++i)
885        ConstrStr += (char)Record[3+AsmStrSize+i];
886      const PointerType *PTy = cast<PointerType>(CurTy);
887      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
888                         AsmStr, ConstrStr, HasSideEffects);
889      break;
890    }
891    }
892
893    ValueList.AssignValue(V, NextCstNo);
894    ++NextCstNo;
895  }
896}
897
898/// RememberAndSkipFunctionBody - When we see the block for a function body,
899/// remember where it is and then skip it.  This lets us lazily deserialize the
900/// functions.
901bool BitcodeReader::RememberAndSkipFunctionBody() {
902  // Get the function we are talking about.
903  if (FunctionsWithBodies.empty())
904    return Error("Insufficient function protos");
905
906  Function *Fn = FunctionsWithBodies.back();
907  FunctionsWithBodies.pop_back();
908
909  // Save the current stream state.
910  uint64_t CurBit = Stream.GetCurrentBitNo();
911  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
912
913  // Set the functions linkage to GhostLinkage so we know it is lazily
914  // deserialized.
915  Fn->setLinkage(GlobalValue::GhostLinkage);
916
917  // Skip over the function block for now.
918  if (Stream.SkipBlock())
919    return Error("Malformed block record");
920  return false;
921}
922
923bool BitcodeReader::ParseModule(const std::string &ModuleID) {
924  // Reject multiple MODULE_BLOCK's in a single bitstream.
925  if (TheModule)
926    return Error("Multiple MODULE_BLOCKs in same stream");
927
928  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
929    return Error("Malformed block record");
930
931  // Otherwise, create the module.
932  TheModule = new Module(ModuleID);
933
934  SmallVector<uint64_t, 64> Record;
935  std::vector<std::string> SectionTable;
936  std::vector<std::string> CollectorTable;
937
938  // Read all the records for this module.
939  while (!Stream.AtEndOfStream()) {
940    unsigned Code = Stream.ReadCode();
941    if (Code == bitc::END_BLOCK) {
942      if (Stream.ReadBlockEnd())
943        return Error("Error at end of module block");
944
945      // Patch the initializers for globals and aliases up.
946      ResolveGlobalAndAliasInits();
947      if (!GlobalInits.empty() || !AliasInits.empty())
948        return Error("Malformed global initializer set");
949      if (!FunctionsWithBodies.empty())
950        return Error("Too few function bodies found");
951
952      // Look for intrinsic functions which need to be upgraded at some point
953      for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
954           FI != FE; ++FI) {
955        Function* NewFn;
956        if (UpgradeIntrinsicFunction(FI, NewFn))
957          UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
958      }
959
960      // Force deallocation of memory for these vectors to favor the client that
961      // want lazy deserialization.
962      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
963      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
964      std::vector<Function*>().swap(FunctionsWithBodies);
965      return false;
966    }
967
968    if (Code == bitc::ENTER_SUBBLOCK) {
969      switch (Stream.ReadSubBlockID()) {
970      default:  // Skip unknown content.
971        if (Stream.SkipBlock())
972          return Error("Malformed block record");
973        break;
974      case bitc::BLOCKINFO_BLOCK_ID:
975        if (Stream.ReadBlockInfoBlock())
976          return Error("Malformed BlockInfoBlock");
977        break;
978      case bitc::PARAMATTR_BLOCK_ID:
979        if (ParseParamAttrBlock())
980          return true;
981        break;
982      case bitc::TYPE_BLOCK_ID:
983        if (ParseTypeTable())
984          return true;
985        break;
986      case bitc::TYPE_SYMTAB_BLOCK_ID:
987        if (ParseTypeSymbolTable())
988          return true;
989        break;
990      case bitc::VALUE_SYMTAB_BLOCK_ID:
991        if (ParseValueSymbolTable())
992          return true;
993        break;
994      case bitc::CONSTANTS_BLOCK_ID:
995        if (ParseConstants() || ResolveGlobalAndAliasInits())
996          return true;
997        break;
998      case bitc::FUNCTION_BLOCK_ID:
999        // If this is the first function body we've seen, reverse the
1000        // FunctionsWithBodies list.
1001        if (!HasReversedFunctionsWithBodies) {
1002          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
1003          HasReversedFunctionsWithBodies = true;
1004        }
1005
1006        if (RememberAndSkipFunctionBody())
1007          return true;
1008        break;
1009      }
1010      continue;
1011    }
1012
1013    if (Code == bitc::DEFINE_ABBREV) {
1014      Stream.ReadAbbrevRecord();
1015      continue;
1016    }
1017
1018    // Read a record.
1019    switch (Stream.ReadRecord(Code, Record)) {
1020    default: break;  // Default behavior, ignore unknown content.
1021    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
1022      if (Record.size() < 1)
1023        return Error("Malformed MODULE_CODE_VERSION");
1024      // Only version #0 is supported so far.
1025      if (Record[0] != 0)
1026        return Error("Unknown bitstream version!");
1027      break;
1028    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1029      std::string S;
1030      if (ConvertToString(Record, 0, S))
1031        return Error("Invalid MODULE_CODE_TRIPLE record");
1032      TheModule->setTargetTriple(S);
1033      break;
1034    }
1035    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
1036      std::string S;
1037      if (ConvertToString(Record, 0, S))
1038        return Error("Invalid MODULE_CODE_DATALAYOUT record");
1039      TheModule->setDataLayout(S);
1040      break;
1041    }
1042    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
1043      std::string S;
1044      if (ConvertToString(Record, 0, S))
1045        return Error("Invalid MODULE_CODE_ASM record");
1046      TheModule->setModuleInlineAsm(S);
1047      break;
1048    }
1049    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
1050      std::string S;
1051      if (ConvertToString(Record, 0, S))
1052        return Error("Invalid MODULE_CODE_DEPLIB record");
1053      TheModule->addLibrary(S);
1054      break;
1055    }
1056    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
1057      std::string S;
1058      if (ConvertToString(Record, 0, S))
1059        return Error("Invalid MODULE_CODE_SECTIONNAME record");
1060      SectionTable.push_back(S);
1061      break;
1062    }
1063    case bitc::MODULE_CODE_COLLECTORNAME: {  // SECTIONNAME: [strchr x N]
1064      std::string S;
1065      if (ConvertToString(Record, 0, S))
1066        return Error("Invalid MODULE_CODE_COLLECTORNAME record");
1067      CollectorTable.push_back(S);
1068      break;
1069    }
1070    // GLOBALVAR: [pointer type, isconst, initid,
1071    //             linkage, alignment, section, visibility, threadlocal]
1072    case bitc::MODULE_CODE_GLOBALVAR: {
1073      if (Record.size() < 6)
1074        return Error("Invalid MODULE_CODE_GLOBALVAR record");
1075      const Type *Ty = getTypeByID(Record[0]);
1076      if (!isa<PointerType>(Ty))
1077        return Error("Global not a pointer type!");
1078      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
1079      Ty = cast<PointerType>(Ty)->getElementType();
1080
1081      bool isConstant = Record[1];
1082      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1083      unsigned Alignment = (1 << Record[4]) >> 1;
1084      std::string Section;
1085      if (Record[5]) {
1086        if (Record[5]-1 >= SectionTable.size())
1087          return Error("Invalid section ID");
1088        Section = SectionTable[Record[5]-1];
1089      }
1090      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1091      if (Record.size() > 6)
1092        Visibility = GetDecodedVisibility(Record[6]);
1093      bool isThreadLocal = false;
1094      if (Record.size() > 7)
1095        isThreadLocal = Record[7];
1096
1097      GlobalVariable *NewGV =
1098        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule,
1099                           isThreadLocal, AddressSpace);
1100      NewGV->setAlignment(Alignment);
1101      if (!Section.empty())
1102        NewGV->setSection(Section);
1103      NewGV->setVisibility(Visibility);
1104      NewGV->setThreadLocal(isThreadLocal);
1105
1106      ValueList.push_back(NewGV);
1107
1108      // Remember which value to use for the global initializer.
1109      if (unsigned InitID = Record[2])
1110        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1111      break;
1112    }
1113    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1114    //             alignment, section, visibility, collector]
1115    case bitc::MODULE_CODE_FUNCTION: {
1116      if (Record.size() < 8)
1117        return Error("Invalid MODULE_CODE_FUNCTION record");
1118      const Type *Ty = getTypeByID(Record[0]);
1119      if (!isa<PointerType>(Ty))
1120        return Error("Function not a pointer type!");
1121      const FunctionType *FTy =
1122        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1123      if (!FTy)
1124        return Error("Function not a pointer to function type!");
1125
1126      Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
1127                                        "", TheModule);
1128
1129      Func->setCallingConv(Record[1]);
1130      bool isProto = Record[2];
1131      Func->setLinkage(GetDecodedLinkage(Record[3]));
1132      Func->setParamAttrs(getParamAttrs(Record[4]));
1133
1134      Func->setAlignment((1 << Record[5]) >> 1);
1135      if (Record[6]) {
1136        if (Record[6]-1 >= SectionTable.size())
1137          return Error("Invalid section ID");
1138        Func->setSection(SectionTable[Record[6]-1]);
1139      }
1140      Func->setVisibility(GetDecodedVisibility(Record[7]));
1141      if (Record.size() > 8 && Record[8]) {
1142        if (Record[8]-1 > CollectorTable.size())
1143          return Error("Invalid collector ID");
1144        Func->setCollector(CollectorTable[Record[8]-1].c_str());
1145      }
1146
1147      ValueList.push_back(Func);
1148
1149      // If this is a function with a body, remember the prototype we are
1150      // creating now, so that we can match up the body with them later.
1151      if (!isProto)
1152        FunctionsWithBodies.push_back(Func);
1153      break;
1154    }
1155    // ALIAS: [alias type, aliasee val#, linkage]
1156    // ALIAS: [alias type, aliasee val#, linkage, visibility]
1157    case bitc::MODULE_CODE_ALIAS: {
1158      if (Record.size() < 3)
1159        return Error("Invalid MODULE_ALIAS record");
1160      const Type *Ty = getTypeByID(Record[0]);
1161      if (!isa<PointerType>(Ty))
1162        return Error("Function not a pointer type!");
1163
1164      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1165                                           "", 0, TheModule);
1166      // Old bitcode files didn't have visibility field.
1167      if (Record.size() > 3)
1168        NewGA->setVisibility(GetDecodedVisibility(Record[3]));
1169      ValueList.push_back(NewGA);
1170      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1171      break;
1172    }
1173    /// MODULE_CODE_PURGEVALS: [numvals]
1174    case bitc::MODULE_CODE_PURGEVALS:
1175      // Trim down the value list to the specified size.
1176      if (Record.size() < 1 || Record[0] > ValueList.size())
1177        return Error("Invalid MODULE_PURGEVALS record");
1178      ValueList.shrinkTo(Record[0]);
1179      break;
1180    }
1181    Record.clear();
1182  }
1183
1184  return Error("Premature end of bitstream");
1185}
1186
1187/// SkipWrapperHeader - Some systems wrap bc files with a special header for
1188/// padding or other reasons.  The format of this header is:
1189///
1190/// struct bc_header {
1191///   uint32_t Magic;         // 0x0B17C0DE
1192///   uint32_t Version;       // Version, currently always 0.
1193///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1194///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1195///   ... potentially other gunk ...
1196/// };
1197///
1198/// This function is called when we find a file with a matching magic number.
1199/// In this case, skip down to the subsection of the file that is actually a BC
1200/// file.
1201static bool SkipWrapperHeader(unsigned char *&BufPtr, unsigned char *&BufEnd) {
1202  enum {
1203    KnownHeaderSize = 4*4,  // Size of header we read.
1204    OffsetField = 2*4,      // Offset in bytes to Offset field.
1205    SizeField = 3*4         // Offset in bytes to Size field.
1206  };
1207
1208
1209  // Must contain the header!
1210  if (BufEnd-BufPtr < KnownHeaderSize) return true;
1211
1212  unsigned Offset = ( BufPtr[OffsetField  ]        |
1213                     (BufPtr[OffsetField+1] << 8)  |
1214                     (BufPtr[OffsetField+2] << 16) |
1215                     (BufPtr[OffsetField+3] << 24));
1216  unsigned Size   = ( BufPtr[SizeField    ]        |
1217                     (BufPtr[SizeField  +1] << 8)  |
1218                     (BufPtr[SizeField  +2] << 16) |
1219                     (BufPtr[SizeField  +3] << 24));
1220
1221  // Verify that Offset+Size fits in the file.
1222  if (Offset+Size > unsigned(BufEnd-BufPtr))
1223    return true;
1224  BufPtr += Offset;
1225  BufEnd = BufPtr+Size;
1226  return false;
1227}
1228
1229bool BitcodeReader::ParseBitcode() {
1230  TheModule = 0;
1231
1232  if (Buffer->getBufferSize() & 3)
1233    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1234
1235  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1236  unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
1237
1238  // If we have a wrapper header, parse it and ignore the non-bc file contents.
1239  // The magic number is 0x0B17C0DE stored in little endian.
1240  if (BufPtr != BufEnd && BufPtr[0] == 0xDE && BufPtr[1] == 0xC0 &&
1241      BufPtr[2] == 0x17 && BufPtr[3] == 0x0B)
1242    if (SkipWrapperHeader(BufPtr, BufEnd))
1243      return Error("Invalid bitcode wrapper header");
1244
1245  Stream.init(BufPtr, BufEnd);
1246
1247  // Sniff for the signature.
1248  if (Stream.Read(8) != 'B' ||
1249      Stream.Read(8) != 'C' ||
1250      Stream.Read(4) != 0x0 ||
1251      Stream.Read(4) != 0xC ||
1252      Stream.Read(4) != 0xE ||
1253      Stream.Read(4) != 0xD)
1254    return Error("Invalid bitcode signature");
1255
1256  // We expect a number of well-defined blocks, though we don't necessarily
1257  // need to understand them all.
1258  while (!Stream.AtEndOfStream()) {
1259    unsigned Code = Stream.ReadCode();
1260
1261    if (Code != bitc::ENTER_SUBBLOCK)
1262      return Error("Invalid record at top-level");
1263
1264    unsigned BlockID = Stream.ReadSubBlockID();
1265
1266    // We only know the MODULE subblock ID.
1267    switch (BlockID) {
1268    case bitc::BLOCKINFO_BLOCK_ID:
1269      if (Stream.ReadBlockInfoBlock())
1270        return Error("Malformed BlockInfoBlock");
1271      break;
1272    case bitc::MODULE_BLOCK_ID:
1273      if (ParseModule(Buffer->getBufferIdentifier()))
1274        return true;
1275      break;
1276    default:
1277      if (Stream.SkipBlock())
1278        return Error("Malformed block record");
1279      break;
1280    }
1281  }
1282
1283  return false;
1284}
1285
1286
1287/// ParseFunctionBody - Lazily parse the specified function body block.
1288bool BitcodeReader::ParseFunctionBody(Function *F) {
1289  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1290    return Error("Malformed block record");
1291
1292  unsigned ModuleValueListSize = ValueList.size();
1293
1294  // Add all the function arguments to the value table.
1295  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1296    ValueList.push_back(I);
1297
1298  unsigned NextValueNo = ValueList.size();
1299  BasicBlock *CurBB = 0;
1300  unsigned CurBBNo = 0;
1301
1302  // Read all the records.
1303  SmallVector<uint64_t, 64> Record;
1304  while (1) {
1305    unsigned Code = Stream.ReadCode();
1306    if (Code == bitc::END_BLOCK) {
1307      if (Stream.ReadBlockEnd())
1308        return Error("Error at end of function block");
1309      break;
1310    }
1311
1312    if (Code == bitc::ENTER_SUBBLOCK) {
1313      switch (Stream.ReadSubBlockID()) {
1314      default:  // Skip unknown content.
1315        if (Stream.SkipBlock())
1316          return Error("Malformed block record");
1317        break;
1318      case bitc::CONSTANTS_BLOCK_ID:
1319        if (ParseConstants()) return true;
1320        NextValueNo = ValueList.size();
1321        break;
1322      case bitc::VALUE_SYMTAB_BLOCK_ID:
1323        if (ParseValueSymbolTable()) return true;
1324        break;
1325      }
1326      continue;
1327    }
1328
1329    if (Code == bitc::DEFINE_ABBREV) {
1330      Stream.ReadAbbrevRecord();
1331      continue;
1332    }
1333
1334    // Read a record.
1335    Record.clear();
1336    Instruction *I = 0;
1337    switch (Stream.ReadRecord(Code, Record)) {
1338    default: // Default behavior: reject
1339      return Error("Unknown instruction");
1340    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1341      if (Record.size() < 1 || Record[0] == 0)
1342        return Error("Invalid DECLAREBLOCKS record");
1343      // Create all the basic blocks for the function.
1344      FunctionBBs.resize(Record[0]);
1345      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1346        FunctionBBs[i] = BasicBlock::Create("", F);
1347      CurBB = FunctionBBs[0];
1348      continue;
1349
1350    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1351      unsigned OpNum = 0;
1352      Value *LHS, *RHS;
1353      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1354          getValue(Record, OpNum, LHS->getType(), RHS) ||
1355          OpNum+1 != Record.size())
1356        return Error("Invalid BINOP record");
1357
1358      int Opc = GetDecodedBinaryOpcode(Record[OpNum], LHS->getType());
1359      if (Opc == -1) return Error("Invalid BINOP record");
1360      I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
1361      break;
1362    }
1363    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
1364      unsigned OpNum = 0;
1365      Value *Op;
1366      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1367          OpNum+2 != Record.size())
1368        return Error("Invalid CAST record");
1369
1370      const Type *ResTy = getTypeByID(Record[OpNum]);
1371      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
1372      if (Opc == -1 || ResTy == 0)
1373        return Error("Invalid CAST record");
1374      I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
1375      break;
1376    }
1377    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
1378      unsigned OpNum = 0;
1379      Value *BasePtr;
1380      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
1381        return Error("Invalid GEP record");
1382
1383      SmallVector<Value*, 16> GEPIdx;
1384      while (OpNum != Record.size()) {
1385        Value *Op;
1386        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1387          return Error("Invalid GEP record");
1388        GEPIdx.push_back(Op);
1389      }
1390
1391      I = GetElementPtrInst::Create(BasePtr, GEPIdx.begin(), GEPIdx.end());
1392      break;
1393    }
1394
1395    case bitc::FUNC_CODE_INST_EXTRACTVAL: {
1396                                       // EXTRACTVAL: [opty, opval, n x indices]
1397      unsigned OpNum = 0;
1398      Value *Agg;
1399      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
1400        return Error("Invalid EXTRACTVAL record");
1401
1402      SmallVector<unsigned, 4> EXTRACTVALIdx;
1403      for (unsigned RecSize = Record.size();
1404           OpNum != RecSize; ++OpNum) {
1405        uint64_t Index = Record[OpNum];
1406        if ((unsigned)Index != Index)
1407          return Error("Invalid EXTRACTVAL index");
1408        EXTRACTVALIdx.push_back((unsigned)Index);
1409      }
1410
1411      I = ExtractValueInst::Create(Agg,
1412                                   EXTRACTVALIdx.begin(), EXTRACTVALIdx.end());
1413      break;
1414    }
1415
1416    case bitc::FUNC_CODE_INST_INSERTVAL: {
1417                           // INSERTVAL: [opty, opval, opty, opval, n x indices]
1418      unsigned OpNum = 0;
1419      Value *Agg;
1420      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
1421        return Error("Invalid INSERTVAL record");
1422      Value *Val;
1423      if (getValueTypePair(Record, OpNum, NextValueNo, Val))
1424        return Error("Invalid INSERTVAL record");
1425
1426      SmallVector<unsigned, 4> INSERTVALIdx;
1427      for (unsigned RecSize = Record.size();
1428           OpNum != RecSize; ++OpNum) {
1429        uint64_t Index = Record[OpNum];
1430        if ((unsigned)Index != Index)
1431          return Error("Invalid INSERTVAL index");
1432        INSERTVALIdx.push_back((unsigned)Index);
1433      }
1434
1435      I = InsertValueInst::Create(Agg, Val,
1436                                  INSERTVALIdx.begin(), INSERTVALIdx.end());
1437      break;
1438    }
1439
1440    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
1441      unsigned OpNum = 0;
1442      Value *TrueVal, *FalseVal, *Cond;
1443      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
1444          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
1445          getValue(Record, OpNum, Type::Int1Ty, Cond))
1446        return Error("Invalid SELECT record");
1447
1448      I = SelectInst::Create(Cond, TrueVal, FalseVal);
1449      break;
1450    }
1451
1452    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1453      unsigned OpNum = 0;
1454      Value *Vec, *Idx;
1455      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1456          getValue(Record, OpNum, Type::Int32Ty, Idx))
1457        return Error("Invalid EXTRACTELT record");
1458      I = new ExtractElementInst(Vec, Idx);
1459      break;
1460    }
1461
1462    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1463      unsigned OpNum = 0;
1464      Value *Vec, *Elt, *Idx;
1465      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1466          getValue(Record, OpNum,
1467                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
1468          getValue(Record, OpNum, Type::Int32Ty, Idx))
1469        return Error("Invalid INSERTELT record");
1470      I = InsertElementInst::Create(Vec, Elt, Idx);
1471      break;
1472    }
1473
1474    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
1475      unsigned OpNum = 0;
1476      Value *Vec1, *Vec2, *Mask;
1477      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
1478          getValue(Record, OpNum, Vec1->getType(), Vec2))
1479        return Error("Invalid SHUFFLEVEC record");
1480
1481      const Type *MaskTy =
1482        VectorType::get(Type::Int32Ty,
1483                        cast<VectorType>(Vec1->getType())->getNumElements());
1484
1485      if (getValue(Record, OpNum, MaskTy, Mask))
1486        return Error("Invalid SHUFFLEVEC record");
1487      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1488      break;
1489    }
1490
1491    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1492      unsigned OpNum = 0;
1493      Value *LHS, *RHS;
1494      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1495          getValue(Record, OpNum, LHS->getType(), RHS) ||
1496          OpNum+1 != Record.size())
1497        return Error("Invalid CMP record");
1498
1499      if (LHS->getType()->isFloatingPoint())
1500        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1501      else if (!isa<VectorType>(LHS->getType()))
1502        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1503      else if (LHS->getType()->isFPOrFPVector())
1504        I = new VFCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1505      else
1506        I = new VICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1507      break;
1508    }
1509    case bitc::FUNC_CODE_INST_GETRESULT: { // GETRESULT: [ty, val, n]
1510      if (Record.size() != 2)
1511        return Error("Invalid GETRESULT record");
1512      unsigned OpNum = 0;
1513      Value *Op;
1514      getValueTypePair(Record, OpNum, NextValueNo, Op);
1515      unsigned Index = Record[1];
1516      I = new GetResultInst(Op, Index);
1517      break;
1518    }
1519
1520    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1521      {
1522        unsigned Size = Record.size();
1523        if (Size == 0) {
1524          I = ReturnInst::Create();
1525          break;
1526        } else {
1527          unsigned OpNum = 0;
1528          SmallVector<Value *,4> Vs;
1529          do {
1530            Value *Op = NULL;
1531            if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1532              return Error("Invalid RET record");
1533            Vs.push_back(Op);
1534          } while(OpNum != Record.size());
1535
1536          // SmallVector Vs has at least one element.
1537          I = ReturnInst::Create(&Vs[0], Vs.size());
1538          break;
1539        }
1540      }
1541    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1542      if (Record.size() != 1 && Record.size() != 3)
1543        return Error("Invalid BR record");
1544      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1545      if (TrueDest == 0)
1546        return Error("Invalid BR record");
1547
1548      if (Record.size() == 1)
1549        I = BranchInst::Create(TrueDest);
1550      else {
1551        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1552        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1553        if (FalseDest == 0 || Cond == 0)
1554          return Error("Invalid BR record");
1555        I = BranchInst::Create(TrueDest, FalseDest, Cond);
1556      }
1557      break;
1558    }
1559    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1560      if (Record.size() < 3 || (Record.size() & 1) == 0)
1561        return Error("Invalid SWITCH record");
1562      const Type *OpTy = getTypeByID(Record[0]);
1563      Value *Cond = getFnValueByID(Record[1], OpTy);
1564      BasicBlock *Default = getBasicBlock(Record[2]);
1565      if (OpTy == 0 || Cond == 0 || Default == 0)
1566        return Error("Invalid SWITCH record");
1567      unsigned NumCases = (Record.size()-3)/2;
1568      SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
1569      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1570        ConstantInt *CaseVal =
1571          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1572        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1573        if (CaseVal == 0 || DestBB == 0) {
1574          delete SI;
1575          return Error("Invalid SWITCH record!");
1576        }
1577        SI->addCase(CaseVal, DestBB);
1578      }
1579      I = SI;
1580      break;
1581    }
1582
1583    case bitc::FUNC_CODE_INST_INVOKE: {
1584      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
1585      if (Record.size() < 4) return Error("Invalid INVOKE record");
1586      PAListPtr PAL = getParamAttrs(Record[0]);
1587      unsigned CCInfo = Record[1];
1588      BasicBlock *NormalBB = getBasicBlock(Record[2]);
1589      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
1590
1591      unsigned OpNum = 4;
1592      Value *Callee;
1593      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1594        return Error("Invalid INVOKE record");
1595
1596      const PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
1597      const FunctionType *FTy = !CalleeTy ? 0 :
1598        dyn_cast<FunctionType>(CalleeTy->getElementType());
1599
1600      // Check that the right number of fixed parameters are here.
1601      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
1602          Record.size() < OpNum+FTy->getNumParams())
1603        return Error("Invalid INVOKE record");
1604
1605      SmallVector<Value*, 16> Ops;
1606      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1607        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1608        if (Ops.back() == 0) return Error("Invalid INVOKE record");
1609      }
1610
1611      if (!FTy->isVarArg()) {
1612        if (Record.size() != OpNum)
1613          return Error("Invalid INVOKE record");
1614      } else {
1615        // Read type/value pairs for varargs params.
1616        while (OpNum != Record.size()) {
1617          Value *Op;
1618          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1619            return Error("Invalid INVOKE record");
1620          Ops.push_back(Op);
1621        }
1622      }
1623
1624      I = InvokeInst::Create(Callee, NormalBB, UnwindBB,
1625                             Ops.begin(), Ops.end());
1626      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1627      cast<InvokeInst>(I)->setParamAttrs(PAL);
1628      break;
1629    }
1630    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1631      I = new UnwindInst();
1632      break;
1633    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1634      I = new UnreachableInst();
1635      break;
1636    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
1637      if (Record.size() < 1 || ((Record.size()-1)&1))
1638        return Error("Invalid PHI record");
1639      const Type *Ty = getTypeByID(Record[0]);
1640      if (!Ty) return Error("Invalid PHI record");
1641
1642      PHINode *PN = PHINode::Create(Ty);
1643      PN->reserveOperandSpace((Record.size()-1)/2);
1644
1645      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
1646        Value *V = getFnValueByID(Record[1+i], Ty);
1647        BasicBlock *BB = getBasicBlock(Record[2+i]);
1648        if (!V || !BB) return Error("Invalid PHI record");
1649        PN->addIncoming(V, BB);
1650      }
1651      I = PN;
1652      break;
1653    }
1654
1655    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1656      if (Record.size() < 3)
1657        return Error("Invalid MALLOC record");
1658      const PointerType *Ty =
1659        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1660      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1661      unsigned Align = Record[2];
1662      if (!Ty || !Size) return Error("Invalid MALLOC record");
1663      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1664      break;
1665    }
1666    case bitc::FUNC_CODE_INST_FREE: { // FREE: [op, opty]
1667      unsigned OpNum = 0;
1668      Value *Op;
1669      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1670          OpNum != Record.size())
1671        return Error("Invalid FREE record");
1672      I = new FreeInst(Op);
1673      break;
1674    }
1675    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1676      if (Record.size() < 3)
1677        return Error("Invalid ALLOCA record");
1678      const PointerType *Ty =
1679        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1680      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1681      unsigned Align = Record[2];
1682      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1683      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1684      break;
1685    }
1686    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1687      unsigned OpNum = 0;
1688      Value *Op;
1689      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1690          OpNum+2 != Record.size())
1691        return Error("Invalid LOAD record");
1692
1693      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1694      break;
1695    }
1696    case bitc::FUNC_CODE_INST_STORE2: { // STORE2:[ptrty, ptr, val, align, vol]
1697      unsigned OpNum = 0;
1698      Value *Val, *Ptr;
1699      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
1700          getValue(Record, OpNum,
1701                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
1702          OpNum+2 != Record.size())
1703        return Error("Invalid STORE record");
1704
1705      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1706      break;
1707    }
1708    case bitc::FUNC_CODE_INST_STORE: { // STORE:[val, valty, ptr, align, vol]
1709      // FIXME: Legacy form of store instruction. Should be removed in LLVM 3.0.
1710      unsigned OpNum = 0;
1711      Value *Val, *Ptr;
1712      if (getValueTypePair(Record, OpNum, NextValueNo, Val) ||
1713          getValue(Record, OpNum, PointerType::getUnqual(Val->getType()), Ptr)||
1714          OpNum+2 != Record.size())
1715        return Error("Invalid STORE record");
1716
1717      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1718      break;
1719    }
1720    case bitc::FUNC_CODE_INST_CALL: {
1721      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
1722      if (Record.size() < 3)
1723        return Error("Invalid CALL record");
1724
1725      PAListPtr PAL = getParamAttrs(Record[0]);
1726      unsigned CCInfo = Record[1];
1727
1728      unsigned OpNum = 2;
1729      Value *Callee;
1730      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1731        return Error("Invalid CALL record");
1732
1733      const PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
1734      const FunctionType *FTy = 0;
1735      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1736      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
1737        return Error("Invalid CALL record");
1738
1739      SmallVector<Value*, 16> Args;
1740      // Read the fixed params.
1741      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1742        if (FTy->getParamType(i)->getTypeID()==Type::LabelTyID)
1743          Args.push_back(getBasicBlock(Record[OpNum]));
1744        else
1745          Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1746        if (Args.back() == 0) return Error("Invalid CALL record");
1747      }
1748
1749      // Read type/value pairs for varargs params.
1750      if (!FTy->isVarArg()) {
1751        if (OpNum != Record.size())
1752          return Error("Invalid CALL record");
1753      } else {
1754        while (OpNum != Record.size()) {
1755          Value *Op;
1756          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1757            return Error("Invalid CALL record");
1758          Args.push_back(Op);
1759        }
1760      }
1761
1762      I = CallInst::Create(Callee, Args.begin(), Args.end());
1763      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1764      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1765      cast<CallInst>(I)->setParamAttrs(PAL);
1766      break;
1767    }
1768    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1769      if (Record.size() < 3)
1770        return Error("Invalid VAARG record");
1771      const Type *OpTy = getTypeByID(Record[0]);
1772      Value *Op = getFnValueByID(Record[1], OpTy);
1773      const Type *ResTy = getTypeByID(Record[2]);
1774      if (!OpTy || !Op || !ResTy)
1775        return Error("Invalid VAARG record");
1776      I = new VAArgInst(Op, ResTy);
1777      break;
1778    }
1779    }
1780
1781    // Add instruction to end of current BB.  If there is no current BB, reject
1782    // this file.
1783    if (CurBB == 0) {
1784      delete I;
1785      return Error("Invalid instruction with no BB");
1786    }
1787    CurBB->getInstList().push_back(I);
1788
1789    // If this was a terminator instruction, move to the next block.
1790    if (isa<TerminatorInst>(I)) {
1791      ++CurBBNo;
1792      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1793    }
1794
1795    // Non-void values get registered in the value table for future use.
1796    if (I && I->getType() != Type::VoidTy)
1797      ValueList.AssignValue(I, NextValueNo++);
1798  }
1799
1800  // Check the function list for unresolved values.
1801  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1802    if (A->getParent() == 0) {
1803      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1804      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1805        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1806          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1807          delete A;
1808        }
1809      }
1810      return Error("Never resolved value found in function!");
1811    }
1812  }
1813
1814  // Trim the value list down to the size it was before we parsed this function.
1815  ValueList.shrinkTo(ModuleValueListSize);
1816  std::vector<BasicBlock*>().swap(FunctionBBs);
1817
1818  return false;
1819}
1820
1821//===----------------------------------------------------------------------===//
1822// ModuleProvider implementation
1823//===----------------------------------------------------------------------===//
1824
1825
1826bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1827  // If it already is material, ignore the request.
1828  if (!F->hasNotBeenReadFromBitcode()) return false;
1829
1830  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1831    DeferredFunctionInfo.find(F);
1832  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1833
1834  // Move the bit stream to the saved position of the deferred function body and
1835  // restore the real linkage type for the function.
1836  Stream.JumpToBit(DFII->second.first);
1837  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1838
1839  if (ParseFunctionBody(F)) {
1840    if (ErrInfo) *ErrInfo = ErrorString;
1841    return true;
1842  }
1843
1844  // Upgrade any old intrinsic calls in the function.
1845  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
1846       E = UpgradedIntrinsics.end(); I != E; ++I) {
1847    if (I->first != I->second) {
1848      for (Value::use_iterator UI = I->first->use_begin(),
1849           UE = I->first->use_end(); UI != UE; ) {
1850        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1851          UpgradeIntrinsicCall(CI, I->second);
1852      }
1853    }
1854  }
1855
1856  return false;
1857}
1858
1859void BitcodeReader::dematerializeFunction(Function *F) {
1860  // If this function isn't materialized, or if it is a proto, this is a noop.
1861  if (F->hasNotBeenReadFromBitcode() || F->isDeclaration())
1862    return;
1863
1864  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
1865
1866  // Just forget the function body, we can remat it later.
1867  F->deleteBody();
1868  F->setLinkage(GlobalValue::GhostLinkage);
1869}
1870
1871
1872Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
1873  for (DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1874       DeferredFunctionInfo.begin(), E = DeferredFunctionInfo.end(); I != E;
1875       ++I) {
1876    Function *F = I->first;
1877    if (F->hasNotBeenReadFromBitcode() &&
1878        materializeFunction(F, ErrInfo))
1879      return 0;
1880  }
1881
1882  // Upgrade any intrinsic calls that slipped through (should not happen!) and
1883  // delete the old functions to clean up. We can't do this unless the entire
1884  // module is materialized because there could always be another function body
1885  // with calls to the old function.
1886  for (std::vector<std::pair<Function*, Function*> >::iterator I =
1887       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
1888    if (I->first != I->second) {
1889      for (Value::use_iterator UI = I->first->use_begin(),
1890           UE = I->first->use_end(); UI != UE; ) {
1891        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1892          UpgradeIntrinsicCall(CI, I->second);
1893      }
1894      ValueList.replaceUsesOfWith(I->first, I->second);
1895      I->first->eraseFromParent();
1896    }
1897  }
1898  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
1899
1900  return TheModule;
1901}
1902
1903
1904/// This method is provided by the parent ModuleProvde class and overriden
1905/// here. It simply releases the module from its provided and frees up our
1906/// state.
1907/// @brief Release our hold on the generated module
1908Module *BitcodeReader::releaseModule(std::string *ErrInfo) {
1909  // Since we're losing control of this Module, we must hand it back complete
1910  Module *M = ModuleProvider::releaseModule(ErrInfo);
1911  FreeState();
1912  return M;
1913}
1914
1915
1916//===----------------------------------------------------------------------===//
1917// External interface
1918//===----------------------------------------------------------------------===//
1919
1920/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1921///
1922ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1923                                               std::string *ErrMsg) {
1924  BitcodeReader *R = new BitcodeReader(Buffer);
1925  if (R->ParseBitcode()) {
1926    if (ErrMsg)
1927      *ErrMsg = R->getErrorString();
1928
1929    // Don't let the BitcodeReader dtor delete 'Buffer'.
1930    R->releaseMemoryBuffer();
1931    delete R;
1932    return 0;
1933  }
1934  return R;
1935}
1936
1937/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
1938/// If an error occurs, return null and fill in *ErrMsg if non-null.
1939Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
1940  BitcodeReader *R;
1941  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
1942  if (!R) return 0;
1943
1944  // Read in the entire module.
1945  Module *M = R->materializeModule(ErrMsg);
1946
1947  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
1948  // there was an error.
1949  R->releaseMemoryBuffer();
1950
1951  // If there was no error, tell ModuleProvider not to delete it when its dtor
1952  // is run.
1953  if (M)
1954    M = R->releaseModule(ErrMsg);
1955
1956  delete R;
1957  return M;
1958}
1959