BitcodeReader.cpp revision 962dde3cef3184f1683d5070c298c9a29509d62e 
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<AttrListPtr>().swap(MAttributes);
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::WeakAnyLinkage;
63  case 2: return GlobalValue::AppendingLinkage;
64  case 3: return GlobalValue::InternalLinkage;
65  case 4: return GlobalValue::LinkOnceAnyLinkage;
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  case 9: return GlobalValue::PrivateLinkage;
71  case 10: return GlobalValue::WeakODRLinkage;
72  case 11: return GlobalValue::LinkOnceODRLinkage;
73  case 12: return GlobalValue::AvailableExternallyLinkage;
74  }
75}
76
77static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
78  switch (Val) {
79  default: // Map unknown visibilities to default.
80  case 0: return GlobalValue::DefaultVisibility;
81  case 1: return GlobalValue::HiddenVisibility;
82  case 2: return GlobalValue::ProtectedVisibility;
83  }
84}
85
86static int GetDecodedCastOpcode(unsigned Val) {
87  switch (Val) {
88  default: return -1;
89  case bitc::CAST_TRUNC   : return Instruction::Trunc;
90  case bitc::CAST_ZEXT    : return Instruction::ZExt;
91  case bitc::CAST_SEXT    : return Instruction::SExt;
92  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
93  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
94  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
95  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
96  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
97  case bitc::CAST_FPEXT   : return Instruction::FPExt;
98  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
99  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
100  case bitc::CAST_BITCAST : return Instruction::BitCast;
101  }
102}
103static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
104  switch (Val) {
105  default: return -1;
106  case bitc::BINOP_ADD:  return Instruction::Add;
107  case bitc::BINOP_SUB:  return Instruction::Sub;
108  case bitc::BINOP_MUL:  return Instruction::Mul;
109  case bitc::BINOP_UDIV: return Instruction::UDiv;
110  case bitc::BINOP_SDIV:
111    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
112  case bitc::BINOP_UREM: return Instruction::URem;
113  case bitc::BINOP_SREM:
114    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
115  case bitc::BINOP_SHL:  return Instruction::Shl;
116  case bitc::BINOP_LSHR: return Instruction::LShr;
117  case bitc::BINOP_ASHR: return Instruction::AShr;
118  case bitc::BINOP_AND:  return Instruction::And;
119  case bitc::BINOP_OR:   return Instruction::Or;
120  case bitc::BINOP_XOR:  return Instruction::Xor;
121  }
122}
123
124namespace llvm {
125namespace {
126  /// @brief A class for maintaining the slot number definition
127  /// as a placeholder for the actual definition for forward constants defs.
128  class ConstantPlaceHolder : public ConstantExpr {
129    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
130    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
131  public:
132    // allocate space for exactly one operand
133    void *operator new(size_t s) {
134      return User::operator new(s, 1);
135    }
136    explicit ConstantPlaceHolder(const Type *Ty)
137      : ConstantExpr(Ty, Instruction::UserOp1, &Op<0>(), 1) {
138      Op<0>() = UndefValue::get(Type::Int32Ty);
139    }
140
141    /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
142    static inline bool classof(const ConstantPlaceHolder *) { return true; }
143    static bool classof(const Value *V) {
144      return isa<ConstantExpr>(V) &&
145             cast<ConstantExpr>(V)->getOpcode() == Instruction::UserOp1;
146    }
147
148
149    /// Provide fast operand accessors
150    //DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
151  };
152}
153
154// FIXME: can we inherit this from ConstantExpr?
155template <>
156struct OperandTraits<ConstantPlaceHolder> : FixedNumOperandTraits<1> {
157};
158}
159
160
161void BitcodeReaderValueList::AssignValue(Value *V, unsigned Idx) {
162  if (Idx == size()) {
163    push_back(V);
164    return;
165  }
166
167  if (Idx >= size())
168    resize(Idx+1);
169
170  WeakVH &OldV = ValuePtrs[Idx];
171  if (OldV == 0) {
172    OldV = V;
173    return;
174  }
175
176  // Handle constants and non-constants (e.g. instrs) differently for
177  // efficiency.
178  if (Constant *PHC = dyn_cast<Constant>(&*OldV)) {
179    ResolveConstants.push_back(std::make_pair(PHC, Idx));
180    OldV = V;
181  } else {
182    // If there was a forward reference to this value, replace it.
183    Value *PrevVal = OldV;
184    OldV->replaceAllUsesWith(V);
185    delete PrevVal;
186  }
187}
188
189
190Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
191                                                    const Type *Ty) {
192  if (Idx >= size())
193    resize(Idx + 1);
194
195  if (Value *V = ValuePtrs[Idx]) {
196    assert(Ty == V->getType() && "Type mismatch in constant table!");
197    return cast<Constant>(V);
198  }
199
200  // Create and return a placeholder, which will later be RAUW'd.
201  Constant *C = new ConstantPlaceHolder(Ty);
202  ValuePtrs[Idx] = C;
203  return C;
204}
205
206Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
207  if (Idx >= size())
208    resize(Idx + 1);
209
210  if (Value *V = ValuePtrs[Idx]) {
211    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
212    return V;
213  }
214
215  // No type specified, must be invalid reference.
216  if (Ty == 0) return 0;
217
218  // Create and return a placeholder, which will later be RAUW'd.
219  Value *V = new Argument(Ty);
220  ValuePtrs[Idx] = V;
221  return V;
222}
223
224/// ResolveConstantForwardRefs - Once all constants are read, this method bulk
225/// resolves any forward references.  The idea behind this is that we sometimes
226/// get constants (such as large arrays) which reference *many* forward ref
227/// constants.  Replacing each of these causes a lot of thrashing when
228/// building/reuniquing the constant.  Instead of doing this, we look at all the
229/// uses and rewrite all the place holders at once for any constant that uses
230/// a placeholder.
231void BitcodeReaderValueList::ResolveConstantForwardRefs() {
232  // Sort the values by-pointer so that they are efficient to look up with a
233  // binary search.
234  std::sort(ResolveConstants.begin(), ResolveConstants.end());
235
236  SmallVector<Constant*, 64> NewOps;
237
238  while (!ResolveConstants.empty()) {
239    Value *RealVal = operator[](ResolveConstants.back().second);
240    Constant *Placeholder = ResolveConstants.back().first;
241    ResolveConstants.pop_back();
242
243    // Loop over all users of the placeholder, updating them to reference the
244    // new value.  If they reference more than one placeholder, update them all
245    // at once.
246    while (!Placeholder->use_empty()) {
247      Value::use_iterator UI = Placeholder->use_begin();
248
249      // If the using object isn't uniqued, just update the operands.  This
250      // handles instructions and initializers for global variables.
251      if (!isa<Constant>(*UI) || isa<GlobalValue>(*UI)) {
252        UI.getUse().set(RealVal);
253        continue;
254      }
255
256      // Otherwise, we have a constant that uses the placeholder.  Replace that
257      // constant with a new constant that has *all* placeholder uses updated.
258      Constant *UserC = cast<Constant>(*UI);
259      for (User::op_iterator I = UserC->op_begin(), E = UserC->op_end();
260           I != E; ++I) {
261        Value *NewOp;
262        if (!isa<ConstantPlaceHolder>(*I)) {
263          // Not a placeholder reference.
264          NewOp = *I;
265        } else if (*I == Placeholder) {
266          // Common case is that it just references this one placeholder.
267          NewOp = RealVal;
268        } else {
269          // Otherwise, look up the placeholder in ResolveConstants.
270          ResolveConstantsTy::iterator It =
271            std::lower_bound(ResolveConstants.begin(), ResolveConstants.end(),
272                             std::pair<Constant*, unsigned>(cast<Constant>(*I),
273                                                            0));
274          assert(It != ResolveConstants.end() && It->first == *I);
275          NewOp = operator[](It->second);
276        }
277
278        NewOps.push_back(cast<Constant>(NewOp));
279      }
280
281      // Make the new constant.
282      Constant *NewC;
283      if (ConstantArray *UserCA = dyn_cast<ConstantArray>(UserC)) {
284        NewC = ConstantArray::get(UserCA->getType(), &NewOps[0], NewOps.size());
285      } else if (ConstantStruct *UserCS = dyn_cast<ConstantStruct>(UserC)) {
286        NewC = ConstantStruct::get(&NewOps[0], NewOps.size(),
287                                   UserCS->getType()->isPacked());
288      } else if (isa<ConstantVector>(UserC)) {
289        NewC = ConstantVector::get(&NewOps[0], NewOps.size());
290      } else if (isa<ConstantExpr>(UserC)) {
291        NewC = cast<ConstantExpr>(UserC)->getWithOperands(&NewOps[0],
292                                                          NewOps.size());
293      } else {
294        assert(isa<MDNode>(UserC) && "Must be a metadata node.");
295        NewC = MDNode::get(&NewOps[0], NewOps.size());
296      }
297
298      UserC->replaceAllUsesWith(NewC);
299      UserC->destroyConstant();
300      NewOps.clear();
301    }
302
303    delete Placeholder;
304  }
305}
306
307
308const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
309  // If the TypeID is in range, return it.
310  if (ID < TypeList.size())
311    return TypeList[ID].get();
312  if (!isTypeTable) return 0;
313
314  // The type table allows forward references.  Push as many Opaque types as
315  // needed to get up to ID.
316  while (TypeList.size() <= ID)
317    TypeList.push_back(OpaqueType::get());
318  return TypeList.back().get();
319}
320
321//===----------------------------------------------------------------------===//
322//  Functions for parsing blocks from the bitcode file
323//===----------------------------------------------------------------------===//
324
325bool BitcodeReader::ParseAttributeBlock() {
326  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
327    return Error("Malformed block record");
328
329  if (!MAttributes.empty())
330    return Error("Multiple PARAMATTR blocks found!");
331
332  SmallVector<uint64_t, 64> Record;
333
334  SmallVector<AttributeWithIndex, 8> Attrs;
335
336  // Read all the records.
337  while (1) {
338    unsigned Code = Stream.ReadCode();
339    if (Code == bitc::END_BLOCK) {
340      if (Stream.ReadBlockEnd())
341        return Error("Error at end of PARAMATTR block");
342      return false;
343    }
344
345    if (Code == bitc::ENTER_SUBBLOCK) {
346      // No known subblocks, always skip them.
347      Stream.ReadSubBlockID();
348      if (Stream.SkipBlock())
349        return Error("Malformed block record");
350      continue;
351    }
352
353    if (Code == bitc::DEFINE_ABBREV) {
354      Stream.ReadAbbrevRecord();
355      continue;
356    }
357
358    // Read a record.
359    Record.clear();
360    switch (Stream.ReadRecord(Code, Record)) {
361    default:  // Default behavior: ignore.
362      break;
363    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
364      if (Record.size() & 1)
365        return Error("Invalid ENTRY record");
366
367      // FIXME : Remove this autoupgrade code in LLVM 3.0.
368      // If Function attributes are using index 0 then transfer them
369      // to index ~0. Index 0 is used for return value attributes but used to be
370      // used for function attributes.
371      Attributes RetAttribute = Attribute::None;
372      Attributes FnAttribute = Attribute::None;
373      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
374        // FIXME: remove in LLVM 3.0
375        // The alignment is stored as a 16-bit raw value from bits 31--16.
376        // We shift the bits above 31 down by 11 bits.
377
378        unsigned Alignment = (Record[i+1] & (0xffffull << 16)) >> 16;
379        if (Alignment && !isPowerOf2_32(Alignment))
380          return Error("Alignment is not a power of two.");
381
382        Attributes ReconstitutedAttr = Record[i+1] & 0xffff;
383        if (Alignment)
384          ReconstitutedAttr |= Attribute::constructAlignmentFromInt(Alignment);
385        ReconstitutedAttr |= (Record[i+1] & (0xffffull << 32)) >> 11;
386        Record[i+1] = ReconstitutedAttr;
387
388        if (Record[i] == 0)
389          RetAttribute = Record[i+1];
390        else if (Record[i] == ~0U)
391          FnAttribute = Record[i+1];
392      }
393
394      unsigned OldRetAttrs = (Attribute::NoUnwind|Attribute::NoReturn|
395                              Attribute::ReadOnly|Attribute::ReadNone);
396
397      if (FnAttribute == Attribute::None && RetAttribute != Attribute::None &&
398          (RetAttribute & OldRetAttrs) != 0) {
399        if (FnAttribute == Attribute::None) { // add a slot so they get added.
400          Record.push_back(~0U);
401          Record.push_back(0);
402        }
403
404        FnAttribute  |= RetAttribute & OldRetAttrs;
405        RetAttribute &= ~OldRetAttrs;
406      }
407
408      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
409        if (Record[i] == 0) {
410          if (RetAttribute != Attribute::None)
411            Attrs.push_back(AttributeWithIndex::get(0, RetAttribute));
412        } else if (Record[i] == ~0U) {
413          if (FnAttribute != Attribute::None)
414            Attrs.push_back(AttributeWithIndex::get(~0U, FnAttribute));
415        } else if (Record[i+1] != Attribute::None)
416          Attrs.push_back(AttributeWithIndex::get(Record[i], Record[i+1]));
417      }
418
419      MAttributes.push_back(AttrListPtr::get(Attrs.begin(), Attrs.end()));
420      Attrs.clear();
421      break;
422    }
423    }
424  }
425}
426
427
428bool BitcodeReader::ParseTypeTable() {
429  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID))
430    return Error("Malformed block record");
431
432  if (!TypeList.empty())
433    return Error("Multiple TYPE_BLOCKs found!");
434
435  SmallVector<uint64_t, 64> Record;
436  unsigned NumRecords = 0;
437
438  // Read all the records for this type table.
439  while (1) {
440    unsigned Code = Stream.ReadCode();
441    if (Code == bitc::END_BLOCK) {
442      if (NumRecords != TypeList.size())
443        return Error("Invalid type forward reference in TYPE_BLOCK");
444      if (Stream.ReadBlockEnd())
445        return Error("Error at end of type table block");
446      return false;
447    }
448
449    if (Code == bitc::ENTER_SUBBLOCK) {
450      // No known subblocks, always skip them.
451      Stream.ReadSubBlockID();
452      if (Stream.SkipBlock())
453        return Error("Malformed block record");
454      continue;
455    }
456
457    if (Code == bitc::DEFINE_ABBREV) {
458      Stream.ReadAbbrevRecord();
459      continue;
460    }
461
462    // Read a record.
463    Record.clear();
464    const Type *ResultTy = 0;
465    switch (Stream.ReadRecord(Code, Record)) {
466    default:  // Default behavior: unknown type.
467      ResultTy = 0;
468      break;
469    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
470      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
471      // type list.  This allows us to reserve space.
472      if (Record.size() < 1)
473        return Error("Invalid TYPE_CODE_NUMENTRY record");
474      TypeList.reserve(Record[0]);
475      continue;
476    case bitc::TYPE_CODE_VOID:      // VOID
477      ResultTy = Type::VoidTy;
478      break;
479    case bitc::TYPE_CODE_FLOAT:     // FLOAT
480      ResultTy = Type::FloatTy;
481      break;
482    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
483      ResultTy = Type::DoubleTy;
484      break;
485    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
486      ResultTy = Type::X86_FP80Ty;
487      break;
488    case bitc::TYPE_CODE_FP128:     // FP128
489      ResultTy = Type::FP128Ty;
490      break;
491    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
492      ResultTy = Type::PPC_FP128Ty;
493      break;
494    case bitc::TYPE_CODE_LABEL:     // LABEL
495      ResultTy = Type::LabelTy;
496      break;
497    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
498      ResultTy = 0;
499      break;
500    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
501      if (Record.size() < 1)
502        return Error("Invalid Integer type record");
503
504      ResultTy = IntegerType::get(Record[0]);
505      break;
506    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
507                                    //          [pointee type, address space]
508      if (Record.size() < 1)
509        return Error("Invalid POINTER type record");
510      unsigned AddressSpace = 0;
511      if (Record.size() == 2)
512        AddressSpace = Record[1];
513      ResultTy = PointerType::get(getTypeByID(Record[0], true), AddressSpace);
514      break;
515    }
516    case bitc::TYPE_CODE_FUNCTION: {
517      // FIXME: attrid is dead, remove it in LLVM 3.0
518      // FUNCTION: [vararg, attrid, retty, paramty x N]
519      if (Record.size() < 3)
520        return Error("Invalid FUNCTION type record");
521      std::vector<const Type*> ArgTys;
522      for (unsigned i = 3, e = Record.size(); i != e; ++i)
523        ArgTys.push_back(getTypeByID(Record[i], true));
524
525      ResultTy = FunctionType::get(getTypeByID(Record[2], true), ArgTys,
526                                   Record[0]);
527      break;
528    }
529    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, eltty x N]
530      if (Record.size() < 1)
531        return Error("Invalid STRUCT type record");
532      std::vector<const Type*> EltTys;
533      for (unsigned i = 1, e = Record.size(); i != e; ++i)
534        EltTys.push_back(getTypeByID(Record[i], true));
535      ResultTy = StructType::get(EltTys, Record[0]);
536      break;
537    }
538    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
539      if (Record.size() < 2)
540        return Error("Invalid ARRAY type record");
541      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
542      break;
543    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
544      if (Record.size() < 2)
545        return Error("Invalid VECTOR type record");
546      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
547      break;
548    }
549
550    if (NumRecords == TypeList.size()) {
551      // If this is a new type slot, just append it.
552      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
553      ++NumRecords;
554    } else if (ResultTy == 0) {
555      // Otherwise, this was forward referenced, so an opaque type was created,
556      // but the result type is actually just an opaque.  Leave the one we
557      // created previously.
558      ++NumRecords;
559    } else {
560      // Otherwise, this was forward referenced, so an opaque type was created.
561      // Resolve the opaque type to the real type now.
562      assert(NumRecords < TypeList.size() && "Typelist imbalance");
563      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
564
565      // Don't directly push the new type on the Tab. Instead we want to replace
566      // the opaque type we previously inserted with the new concrete value. The
567      // refinement from the abstract (opaque) type to the new type causes all
568      // uses of the abstract type to use the concrete type (NewTy). This will
569      // also cause the opaque type to be deleted.
570      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
571
572      // This should have replaced the old opaque type with the new type in the
573      // value table... or with a preexisting type that was already in the
574      // system.  Let's just make sure it did.
575      assert(TypeList[NumRecords-1].get() != OldTy &&
576             "refineAbstractType didn't work!");
577    }
578  }
579}
580
581
582bool BitcodeReader::ParseTypeSymbolTable() {
583  if (Stream.EnterSubBlock(bitc::TYPE_SYMTAB_BLOCK_ID))
584    return Error("Malformed block record");
585
586  SmallVector<uint64_t, 64> Record;
587
588  // Read all the records for this type table.
589  std::string TypeName;
590  while (1) {
591    unsigned Code = Stream.ReadCode();
592    if (Code == bitc::END_BLOCK) {
593      if (Stream.ReadBlockEnd())
594        return Error("Error at end of type symbol table block");
595      return false;
596    }
597
598    if (Code == bitc::ENTER_SUBBLOCK) {
599      // No known subblocks, always skip them.
600      Stream.ReadSubBlockID();
601      if (Stream.SkipBlock())
602        return Error("Malformed block record");
603      continue;
604    }
605
606    if (Code == bitc::DEFINE_ABBREV) {
607      Stream.ReadAbbrevRecord();
608      continue;
609    }
610
611    // Read a record.
612    Record.clear();
613    switch (Stream.ReadRecord(Code, Record)) {
614    default:  // Default behavior: unknown type.
615      break;
616    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namechar x N]
617      if (ConvertToString(Record, 1, TypeName))
618        return Error("Invalid TST_ENTRY record");
619      unsigned TypeID = Record[0];
620      if (TypeID >= TypeList.size())
621        return Error("Invalid Type ID in TST_ENTRY record");
622
623      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
624      TypeName.clear();
625      break;
626    }
627  }
628}
629
630bool BitcodeReader::ParseValueSymbolTable() {
631  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
632    return Error("Malformed block record");
633
634  SmallVector<uint64_t, 64> Record;
635
636  // Read all the records for this value table.
637  SmallString<128> ValueName;
638  while (1) {
639    unsigned Code = Stream.ReadCode();
640    if (Code == bitc::END_BLOCK) {
641      if (Stream.ReadBlockEnd())
642        return Error("Error at end of value symbol table block");
643      return false;
644    }
645    if (Code == bitc::ENTER_SUBBLOCK) {
646      // No known subblocks, always skip them.
647      Stream.ReadSubBlockID();
648      if (Stream.SkipBlock())
649        return Error("Malformed block record");
650      continue;
651    }
652
653    if (Code == bitc::DEFINE_ABBREV) {
654      Stream.ReadAbbrevRecord();
655      continue;
656    }
657
658    // Read a record.
659    Record.clear();
660    switch (Stream.ReadRecord(Code, Record)) {
661    default:  // Default behavior: unknown type.
662      break;
663    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
664      if (ConvertToString(Record, 1, ValueName))
665        return Error("Invalid TST_ENTRY record");
666      unsigned ValueID = Record[0];
667      if (ValueID >= ValueList.size())
668        return Error("Invalid Value ID in VST_ENTRY record");
669      Value *V = ValueList[ValueID];
670
671      V->setName(&ValueName[0], ValueName.size());
672      ValueName.clear();
673      break;
674    }
675    case bitc::VST_CODE_BBENTRY: {
676      if (ConvertToString(Record, 1, ValueName))
677        return Error("Invalid VST_BBENTRY record");
678      BasicBlock *BB = getBasicBlock(Record[0]);
679      if (BB == 0)
680        return Error("Invalid BB ID in VST_BBENTRY record");
681
682      BB->setName(&ValueName[0], ValueName.size());
683      ValueName.clear();
684      break;
685    }
686    }
687  }
688}
689
690/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
691/// the LSB for dense VBR encoding.
692static uint64_t DecodeSignRotatedValue(uint64_t V) {
693  if ((V & 1) == 0)
694    return V >> 1;
695  if (V != 1)
696    return -(V >> 1);
697  // There is no such thing as -0 with integers.  "-0" really means MININT.
698  return 1ULL << 63;
699}
700
701/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
702/// values and aliases that we can.
703bool BitcodeReader::ResolveGlobalAndAliasInits() {
704  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
705  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
706
707  GlobalInitWorklist.swap(GlobalInits);
708  AliasInitWorklist.swap(AliasInits);
709
710  while (!GlobalInitWorklist.empty()) {
711    unsigned ValID = GlobalInitWorklist.back().second;
712    if (ValID >= ValueList.size()) {
713      // Not ready to resolve this yet, it requires something later in the file.
714      GlobalInits.push_back(GlobalInitWorklist.back());
715    } else {
716      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
717        GlobalInitWorklist.back().first->setInitializer(C);
718      else
719        return Error("Global variable initializer is not a constant!");
720    }
721    GlobalInitWorklist.pop_back();
722  }
723
724  while (!AliasInitWorklist.empty()) {
725    unsigned ValID = AliasInitWorklist.back().second;
726    if (ValID >= ValueList.size()) {
727      AliasInits.push_back(AliasInitWorklist.back());
728    } else {
729      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
730        AliasInitWorklist.back().first->setAliasee(C);
731      else
732        return Error("Alias initializer is not a constant!");
733    }
734    AliasInitWorklist.pop_back();
735  }
736  return false;
737}
738
739
740bool BitcodeReader::ParseConstants() {
741  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
742    return Error("Malformed block record");
743
744  SmallVector<uint64_t, 64> Record;
745
746  // Read all the records for this value table.
747  const Type *CurTy = Type::Int32Ty;
748  unsigned NextCstNo = ValueList.size();
749  while (1) {
750    unsigned Code = Stream.ReadCode();
751    if (Code == bitc::END_BLOCK)
752      break;
753
754    if (Code == bitc::ENTER_SUBBLOCK) {
755      // No known subblocks, always skip them.
756      Stream.ReadSubBlockID();
757      if (Stream.SkipBlock())
758        return Error("Malformed block record");
759      continue;
760    }
761
762    if (Code == bitc::DEFINE_ABBREV) {
763      Stream.ReadAbbrevRecord();
764      continue;
765    }
766
767    // Read a record.
768    Record.clear();
769    Value *V = 0;
770    switch (Stream.ReadRecord(Code, Record)) {
771    default:  // Default behavior: unknown constant
772    case bitc::CST_CODE_UNDEF:     // UNDEF
773      V = UndefValue::get(CurTy);
774      break;
775    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
776      if (Record.empty())
777        return Error("Malformed CST_SETTYPE record");
778      if (Record[0] >= TypeList.size())
779        return Error("Invalid Type ID in CST_SETTYPE record");
780      CurTy = TypeList[Record[0]];
781      continue;  // Skip the ValueList manipulation.
782    case bitc::CST_CODE_NULL:      // NULL
783      V = Constant::getNullValue(CurTy);
784      break;
785    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
786      if (!isa<IntegerType>(CurTy) || Record.empty())
787        return Error("Invalid CST_INTEGER record");
788      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
789      break;
790    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
791      if (!isa<IntegerType>(CurTy) || Record.empty())
792        return Error("Invalid WIDE_INTEGER record");
793
794      unsigned NumWords = Record.size();
795      SmallVector<uint64_t, 8> Words;
796      Words.resize(NumWords);
797      for (unsigned i = 0; i != NumWords; ++i)
798        Words[i] = DecodeSignRotatedValue(Record[i]);
799      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
800                                 NumWords, &Words[0]));
801      break;
802    }
803    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
804      if (Record.empty())
805        return Error("Invalid FLOAT record");
806      if (CurTy == Type::FloatTy)
807        V = ConstantFP::get(APFloat(APInt(32, (uint32_t)Record[0])));
808      else if (CurTy == Type::DoubleTy)
809        V = ConstantFP::get(APFloat(APInt(64, Record[0])));
810      else if (CurTy == Type::X86_FP80Ty) {
811        // Bits are not stored the same way as a normal i80 APInt, compensate.
812        uint64_t Rearrange[2];
813        Rearrange[0] = (Record[1] & 0xffffLL) | (Record[0] << 16);
814        Rearrange[1] = Record[0] >> 48;
815        V = ConstantFP::get(APFloat(APInt(80, 2, Rearrange)));
816      } else if (CurTy == Type::FP128Ty)
817        V = ConstantFP::get(APFloat(APInt(128, 2, &Record[0]), true));
818      else if (CurTy == Type::PPC_FP128Ty)
819        V = ConstantFP::get(APFloat(APInt(128, 2, &Record[0])));
820      else
821        V = UndefValue::get(CurTy);
822      break;
823    }
824
825    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
826      if (Record.empty())
827        return Error("Invalid CST_AGGREGATE record");
828
829      unsigned Size = Record.size();
830      std::vector<Constant*> Elts;
831
832      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
833        for (unsigned i = 0; i != Size; ++i)
834          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
835                                                     STy->getElementType(i)));
836        V = ConstantStruct::get(STy, Elts);
837      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
838        const Type *EltTy = ATy->getElementType();
839        for (unsigned i = 0; i != Size; ++i)
840          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
841        V = ConstantArray::get(ATy, Elts);
842      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
843        const Type *EltTy = VTy->getElementType();
844        for (unsigned i = 0; i != Size; ++i)
845          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
846        V = ConstantVector::get(Elts);
847      } else {
848        V = UndefValue::get(CurTy);
849      }
850      break;
851    }
852    case bitc::CST_CODE_STRING: { // STRING: [values]
853      if (Record.empty())
854        return Error("Invalid CST_AGGREGATE record");
855
856      const ArrayType *ATy = cast<ArrayType>(CurTy);
857      const Type *EltTy = ATy->getElementType();
858
859      unsigned Size = Record.size();
860      std::vector<Constant*> Elts;
861      for (unsigned i = 0; i != Size; ++i)
862        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
863      V = ConstantArray::get(ATy, Elts);
864      break;
865    }
866    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
867      if (Record.empty())
868        return Error("Invalid CST_AGGREGATE record");
869
870      const ArrayType *ATy = cast<ArrayType>(CurTy);
871      const Type *EltTy = ATy->getElementType();
872
873      unsigned Size = Record.size();
874      std::vector<Constant*> Elts;
875      for (unsigned i = 0; i != Size; ++i)
876        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
877      Elts.push_back(Constant::getNullValue(EltTy));
878      V = ConstantArray::get(ATy, Elts);
879      break;
880    }
881    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
882      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
883      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
884      if (Opc < 0) {
885        V = UndefValue::get(CurTy);  // Unknown binop.
886      } else {
887        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
888        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
889        V = ConstantExpr::get(Opc, LHS, RHS);
890      }
891      break;
892    }
893    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
894      if (Record.size() < 3) return Error("Invalid CE_CAST record");
895      int Opc = GetDecodedCastOpcode(Record[0]);
896      if (Opc < 0) {
897        V = UndefValue::get(CurTy);  // Unknown cast.
898      } else {
899        const Type *OpTy = getTypeByID(Record[1]);
900        if (!OpTy) return Error("Invalid CE_CAST record");
901        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
902        V = ConstantExpr::getCast(Opc, Op, CurTy);
903      }
904      break;
905    }
906    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
907      if (Record.size() & 1) return Error("Invalid CE_GEP record");
908      SmallVector<Constant*, 16> Elts;
909      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
910        const Type *ElTy = getTypeByID(Record[i]);
911        if (!ElTy) return Error("Invalid CE_GEP record");
912        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
913      }
914      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
915      break;
916    }
917    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
918      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
919      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
920                                                              Type::Int1Ty),
921                                  ValueList.getConstantFwdRef(Record[1],CurTy),
922                                  ValueList.getConstantFwdRef(Record[2],CurTy));
923      break;
924    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
925      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
926      const VectorType *OpTy =
927        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
928      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
929      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
930      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
931      V = ConstantExpr::getExtractElement(Op0, Op1);
932      break;
933    }
934    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
935      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
936      if (Record.size() < 3 || OpTy == 0)
937        return Error("Invalid CE_INSERTELT record");
938      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
939      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
940                                                  OpTy->getElementType());
941      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
942      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
943      break;
944    }
945    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
946      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
947      if (Record.size() < 3 || OpTy == 0)
948        return Error("Invalid CE_SHUFFLEVEC record");
949      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
950      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
951      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
952      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
953      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
954      break;
955    }
956    case bitc::CST_CODE_CE_SHUFVEC_EX: { // [opty, opval, opval, opval]
957      const VectorType *RTy = dyn_cast<VectorType>(CurTy);
958      const VectorType *OpTy = dyn_cast<VectorType>(getTypeByID(Record[0]));
959      if (Record.size() < 4 || RTy == 0 || OpTy == 0)
960        return Error("Invalid CE_SHUFVEC_EX record");
961      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
962      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
963      const Type *ShufTy=VectorType::get(Type::Int32Ty, RTy->getNumElements());
964      Constant *Op2 = ValueList.getConstantFwdRef(Record[3], ShufTy);
965      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
966      break;
967    }
968    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
969      if (Record.size() < 4) return Error("Invalid CE_CMP record");
970      const Type *OpTy = getTypeByID(Record[0]);
971      if (OpTy == 0) return Error("Invalid CE_CMP record");
972      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
973      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
974
975      if (OpTy->isFloatingPoint())
976        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
977      else if (!isa<VectorType>(OpTy))
978        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
979      else if (OpTy->isFPOrFPVector())
980        V = ConstantExpr::getVFCmp(Record[3], Op0, Op1);
981      else
982        V = ConstantExpr::getVICmp(Record[3], Op0, Op1);
983      break;
984    }
985    case bitc::CST_CODE_INLINEASM: {
986      if (Record.size() < 2) return Error("Invalid INLINEASM record");
987      std::string AsmStr, ConstrStr;
988      bool HasSideEffects = Record[0];
989      unsigned AsmStrSize = Record[1];
990      if (2+AsmStrSize >= Record.size())
991        return Error("Invalid INLINEASM record");
992      unsigned ConstStrSize = Record[2+AsmStrSize];
993      if (3+AsmStrSize+ConstStrSize > Record.size())
994        return Error("Invalid INLINEASM record");
995
996      for (unsigned i = 0; i != AsmStrSize; ++i)
997        AsmStr += (char)Record[2+i];
998      for (unsigned i = 0; i != ConstStrSize; ++i)
999        ConstrStr += (char)Record[3+AsmStrSize+i];
1000      const PointerType *PTy = cast<PointerType>(CurTy);
1001      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
1002                         AsmStr, ConstrStr, HasSideEffects);
1003      break;
1004    }
1005    case bitc::CST_CODE_MDSTRING: {
1006      if (Record.size() < 2) return Error("Invalid MDSTRING record");
1007      unsigned MDStringLength = Record.size();
1008      SmallString<8> String;
1009      String.resize(MDStringLength);
1010      for (unsigned i = 0; i != MDStringLength; ++i)
1011        String[i] = Record[i];
1012      V = MDString::get(String.c_str(), String.c_str() + MDStringLength);
1013      break;
1014    }
1015    case bitc::CST_CODE_MDNODE: {
1016      if (Record.empty() || Record.size() % 2 == 1)
1017        return Error("Invalid CST_MDNODE record");
1018
1019      unsigned Size = Record.size();
1020      SmallVector<Constant*, 8> Elts;
1021      for (unsigned i = 0; i != Size; i += 2) {
1022        const Type *Ty = getTypeByID(Record[i], false);
1023        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], Ty));
1024      }
1025      V = MDNode::get(&Elts[0], Elts.size());
1026      break;
1027    }
1028    }
1029
1030    ValueList.AssignValue(V, NextCstNo);
1031    ++NextCstNo;
1032  }
1033
1034  if (NextCstNo != ValueList.size())
1035    return Error("Invalid constant reference!");
1036
1037  if (Stream.ReadBlockEnd())
1038    return Error("Error at end of constants block");
1039
1040  // Once all the constants have been read, go through and resolve forward
1041  // references.
1042  ValueList.ResolveConstantForwardRefs();
1043  return false;
1044}
1045
1046/// RememberAndSkipFunctionBody - When we see the block for a function body,
1047/// remember where it is and then skip it.  This lets us lazily deserialize the
1048/// functions.
1049bool BitcodeReader::RememberAndSkipFunctionBody() {
1050  // Get the function we are talking about.
1051  if (FunctionsWithBodies.empty())
1052    return Error("Insufficient function protos");
1053
1054  Function *Fn = FunctionsWithBodies.back();
1055  FunctionsWithBodies.pop_back();
1056
1057  // Save the current stream state.
1058  uint64_t CurBit = Stream.GetCurrentBitNo();
1059  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
1060
1061  // Set the functions linkage to GhostLinkage so we know it is lazily
1062  // deserialized.
1063  Fn->setLinkage(GlobalValue::GhostLinkage);
1064
1065  // Skip over the function block for now.
1066  if (Stream.SkipBlock())
1067    return Error("Malformed block record");
1068  return false;
1069}
1070
1071bool BitcodeReader::ParseModule(const std::string &ModuleID) {
1072  // Reject multiple MODULE_BLOCK's in a single bitstream.
1073  if (TheModule)
1074    return Error("Multiple MODULE_BLOCKs in same stream");
1075
1076  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
1077    return Error("Malformed block record");
1078
1079  // Otherwise, create the module.
1080  TheModule = new Module(ModuleID);
1081
1082  SmallVector<uint64_t, 64> Record;
1083  std::vector<std::string> SectionTable;
1084  std::vector<std::string> GCTable;
1085
1086  // Read all the records for this module.
1087  while (!Stream.AtEndOfStream()) {
1088    unsigned Code = Stream.ReadCode();
1089    if (Code == bitc::END_BLOCK) {
1090      if (Stream.ReadBlockEnd())
1091        return Error("Error at end of module block");
1092
1093      // Patch the initializers for globals and aliases up.
1094      ResolveGlobalAndAliasInits();
1095      if (!GlobalInits.empty() || !AliasInits.empty())
1096        return Error("Malformed global initializer set");
1097      if (!FunctionsWithBodies.empty())
1098        return Error("Too few function bodies found");
1099
1100      // Look for intrinsic functions which need to be upgraded at some point
1101      for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
1102           FI != FE; ++FI) {
1103        Function* NewFn;
1104        if (UpgradeIntrinsicFunction(FI, NewFn))
1105          UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
1106      }
1107
1108      // Force deallocation of memory for these vectors to favor the client that
1109      // want lazy deserialization.
1110      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
1111      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
1112      std::vector<Function*>().swap(FunctionsWithBodies);
1113      return false;
1114    }
1115
1116    if (Code == bitc::ENTER_SUBBLOCK) {
1117      switch (Stream.ReadSubBlockID()) {
1118      default:  // Skip unknown content.
1119        if (Stream.SkipBlock())
1120          return Error("Malformed block record");
1121        break;
1122      case bitc::BLOCKINFO_BLOCK_ID:
1123        if (Stream.ReadBlockInfoBlock())
1124          return Error("Malformed BlockInfoBlock");
1125        break;
1126      case bitc::PARAMATTR_BLOCK_ID:
1127        if (ParseAttributeBlock())
1128          return true;
1129        break;
1130      case bitc::TYPE_BLOCK_ID:
1131        if (ParseTypeTable())
1132          return true;
1133        break;
1134      case bitc::TYPE_SYMTAB_BLOCK_ID:
1135        if (ParseTypeSymbolTable())
1136          return true;
1137        break;
1138      case bitc::VALUE_SYMTAB_BLOCK_ID:
1139        if (ParseValueSymbolTable())
1140          return true;
1141        break;
1142      case bitc::CONSTANTS_BLOCK_ID:
1143        if (ParseConstants() || ResolveGlobalAndAliasInits())
1144          return true;
1145        break;
1146      case bitc::FUNCTION_BLOCK_ID:
1147        // If this is the first function body we've seen, reverse the
1148        // FunctionsWithBodies list.
1149        if (!HasReversedFunctionsWithBodies) {
1150          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
1151          HasReversedFunctionsWithBodies = true;
1152        }
1153
1154        if (RememberAndSkipFunctionBody())
1155          return true;
1156        break;
1157      }
1158      continue;
1159    }
1160
1161    if (Code == bitc::DEFINE_ABBREV) {
1162      Stream.ReadAbbrevRecord();
1163      continue;
1164    }
1165
1166    // Read a record.
1167    switch (Stream.ReadRecord(Code, Record)) {
1168    default: break;  // Default behavior, ignore unknown content.
1169    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
1170      if (Record.size() < 1)
1171        return Error("Malformed MODULE_CODE_VERSION");
1172      // Only version #0 is supported so far.
1173      if (Record[0] != 0)
1174        return Error("Unknown bitstream version!");
1175      break;
1176    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1177      std::string S;
1178      if (ConvertToString(Record, 0, S))
1179        return Error("Invalid MODULE_CODE_TRIPLE record");
1180      TheModule->setTargetTriple(S);
1181      break;
1182    }
1183    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
1184      std::string S;
1185      if (ConvertToString(Record, 0, S))
1186        return Error("Invalid MODULE_CODE_DATALAYOUT record");
1187      TheModule->setDataLayout(S);
1188      break;
1189    }
1190    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
1191      std::string S;
1192      if (ConvertToString(Record, 0, S))
1193        return Error("Invalid MODULE_CODE_ASM record");
1194      TheModule->setModuleInlineAsm(S);
1195      break;
1196    }
1197    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
1198      std::string S;
1199      if (ConvertToString(Record, 0, S))
1200        return Error("Invalid MODULE_CODE_DEPLIB record");
1201      TheModule->addLibrary(S);
1202      break;
1203    }
1204    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
1205      std::string S;
1206      if (ConvertToString(Record, 0, S))
1207        return Error("Invalid MODULE_CODE_SECTIONNAME record");
1208      SectionTable.push_back(S);
1209      break;
1210    }
1211    case bitc::MODULE_CODE_GCNAME: {  // SECTIONNAME: [strchr x N]
1212      std::string S;
1213      if (ConvertToString(Record, 0, S))
1214        return Error("Invalid MODULE_CODE_GCNAME record");
1215      GCTable.push_back(S);
1216      break;
1217    }
1218    // GLOBALVAR: [pointer type, isconst, initid,
1219    //             linkage, alignment, section, visibility, threadlocal]
1220    case bitc::MODULE_CODE_GLOBALVAR: {
1221      if (Record.size() < 6)
1222        return Error("Invalid MODULE_CODE_GLOBALVAR record");
1223      const Type *Ty = getTypeByID(Record[0]);
1224      if (!isa<PointerType>(Ty))
1225        return Error("Global not a pointer type!");
1226      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
1227      Ty = cast<PointerType>(Ty)->getElementType();
1228
1229      bool isConstant = Record[1];
1230      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1231      unsigned Alignment = (1 << Record[4]) >> 1;
1232      std::string Section;
1233      if (Record[5]) {
1234        if (Record[5]-1 >= SectionTable.size())
1235          return Error("Invalid section ID");
1236        Section = SectionTable[Record[5]-1];
1237      }
1238      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1239      if (Record.size() > 6)
1240        Visibility = GetDecodedVisibility(Record[6]);
1241      bool isThreadLocal = false;
1242      if (Record.size() > 7)
1243        isThreadLocal = Record[7];
1244
1245      GlobalVariable *NewGV =
1246        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule,
1247                           isThreadLocal, AddressSpace);
1248      NewGV->setAlignment(Alignment);
1249      if (!Section.empty())
1250        NewGV->setSection(Section);
1251      NewGV->setVisibility(Visibility);
1252      NewGV->setThreadLocal(isThreadLocal);
1253
1254      ValueList.push_back(NewGV);
1255
1256      // Remember which value to use for the global initializer.
1257      if (unsigned InitID = Record[2])
1258        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1259      break;
1260    }
1261    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1262    //             alignment, section, visibility, gc]
1263    case bitc::MODULE_CODE_FUNCTION: {
1264      if (Record.size() < 8)
1265        return Error("Invalid MODULE_CODE_FUNCTION record");
1266      const Type *Ty = getTypeByID(Record[0]);
1267      if (!isa<PointerType>(Ty))
1268        return Error("Function not a pointer type!");
1269      const FunctionType *FTy =
1270        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1271      if (!FTy)
1272        return Error("Function not a pointer to function type!");
1273
1274      Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
1275                                        "", TheModule);
1276
1277      Func->setCallingConv(Record[1]);
1278      bool isProto = Record[2];
1279      Func->setLinkage(GetDecodedLinkage(Record[3]));
1280      Func->setAttributes(getAttributes(Record[4]));
1281
1282      Func->setAlignment((1 << Record[5]) >> 1);
1283      if (Record[6]) {
1284        if (Record[6]-1 >= SectionTable.size())
1285          return Error("Invalid section ID");
1286        Func->setSection(SectionTable[Record[6]-1]);
1287      }
1288      Func->setVisibility(GetDecodedVisibility(Record[7]));
1289      if (Record.size() > 8 && Record[8]) {
1290        if (Record[8]-1 > GCTable.size())
1291          return Error("Invalid GC ID");
1292        Func->setGC(GCTable[Record[8]-1].c_str());
1293      }
1294      ValueList.push_back(Func);
1295
1296      // If this is a function with a body, remember the prototype we are
1297      // creating now, so that we can match up the body with them later.
1298      if (!isProto)
1299        FunctionsWithBodies.push_back(Func);
1300      break;
1301    }
1302    // ALIAS: [alias type, aliasee val#, linkage]
1303    // ALIAS: [alias type, aliasee val#, linkage, visibility]
1304    case bitc::MODULE_CODE_ALIAS: {
1305      if (Record.size() < 3)
1306        return Error("Invalid MODULE_ALIAS record");
1307      const Type *Ty = getTypeByID(Record[0]);
1308      if (!isa<PointerType>(Ty))
1309        return Error("Function not a pointer type!");
1310
1311      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1312                                           "", 0, TheModule);
1313      // Old bitcode files didn't have visibility field.
1314      if (Record.size() > 3)
1315        NewGA->setVisibility(GetDecodedVisibility(Record[3]));
1316      ValueList.push_back(NewGA);
1317      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1318      break;
1319    }
1320    /// MODULE_CODE_PURGEVALS: [numvals]
1321    case bitc::MODULE_CODE_PURGEVALS:
1322      // Trim down the value list to the specified size.
1323      if (Record.size() < 1 || Record[0] > ValueList.size())
1324        return Error("Invalid MODULE_PURGEVALS record");
1325      ValueList.shrinkTo(Record[0]);
1326      break;
1327    }
1328    Record.clear();
1329  }
1330
1331  return Error("Premature end of bitstream");
1332}
1333
1334bool BitcodeReader::ParseBitcode() {
1335  TheModule = 0;
1336
1337  if (Buffer->getBufferSize() & 3)
1338    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1339
1340  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1341  unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
1342
1343  // If we have a wrapper header, parse it and ignore the non-bc file contents.
1344  // The magic number is 0x0B17C0DE stored in little endian.
1345  if (isBitcodeWrapper(BufPtr, BufEnd))
1346    if (SkipBitcodeWrapperHeader(BufPtr, BufEnd))
1347      return Error("Invalid bitcode wrapper header");
1348
1349  StreamFile.init(BufPtr, BufEnd);
1350  Stream.init(StreamFile);
1351
1352  // Sniff for the signature.
1353  if (Stream.Read(8) != 'B' ||
1354      Stream.Read(8) != 'C' ||
1355      Stream.Read(4) != 0x0 ||
1356      Stream.Read(4) != 0xC ||
1357      Stream.Read(4) != 0xE ||
1358      Stream.Read(4) != 0xD)
1359    return Error("Invalid bitcode signature");
1360
1361  // We expect a number of well-defined blocks, though we don't necessarily
1362  // need to understand them all.
1363  while (!Stream.AtEndOfStream()) {
1364    unsigned Code = Stream.ReadCode();
1365
1366    if (Code != bitc::ENTER_SUBBLOCK)
1367      return Error("Invalid record at top-level");
1368
1369    unsigned BlockID = Stream.ReadSubBlockID();
1370
1371    // We only know the MODULE subblock ID.
1372    switch (BlockID) {
1373    case bitc::BLOCKINFO_BLOCK_ID:
1374      if (Stream.ReadBlockInfoBlock())
1375        return Error("Malformed BlockInfoBlock");
1376      break;
1377    case bitc::MODULE_BLOCK_ID:
1378      if (ParseModule(Buffer->getBufferIdentifier()))
1379        return true;
1380      break;
1381    default:
1382      if (Stream.SkipBlock())
1383        return Error("Malformed block record");
1384      break;
1385    }
1386  }
1387
1388  return false;
1389}
1390
1391
1392/// ParseFunctionBody - Lazily parse the specified function body block.
1393bool BitcodeReader::ParseFunctionBody(Function *F) {
1394  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1395    return Error("Malformed block record");
1396
1397  unsigned ModuleValueListSize = ValueList.size();
1398
1399  // Add all the function arguments to the value table.
1400  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1401    ValueList.push_back(I);
1402
1403  unsigned NextValueNo = ValueList.size();
1404  BasicBlock *CurBB = 0;
1405  unsigned CurBBNo = 0;
1406
1407  // Read all the records.
1408  SmallVector<uint64_t, 64> Record;
1409  while (1) {
1410    unsigned Code = Stream.ReadCode();
1411    if (Code == bitc::END_BLOCK) {
1412      if (Stream.ReadBlockEnd())
1413        return Error("Error at end of function block");
1414      break;
1415    }
1416
1417    if (Code == bitc::ENTER_SUBBLOCK) {
1418      switch (Stream.ReadSubBlockID()) {
1419      default:  // Skip unknown content.
1420        if (Stream.SkipBlock())
1421          return Error("Malformed block record");
1422        break;
1423      case bitc::CONSTANTS_BLOCK_ID:
1424        if (ParseConstants()) return true;
1425        NextValueNo = ValueList.size();
1426        break;
1427      case bitc::VALUE_SYMTAB_BLOCK_ID:
1428        if (ParseValueSymbolTable()) return true;
1429        break;
1430      }
1431      continue;
1432    }
1433
1434    if (Code == bitc::DEFINE_ABBREV) {
1435      Stream.ReadAbbrevRecord();
1436      continue;
1437    }
1438
1439    // Read a record.
1440    Record.clear();
1441    Instruction *I = 0;
1442    switch (Stream.ReadRecord(Code, Record)) {
1443    default: // Default behavior: reject
1444      return Error("Unknown instruction");
1445    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1446      if (Record.size() < 1 || Record[0] == 0)
1447        return Error("Invalid DECLAREBLOCKS record");
1448      // Create all the basic blocks for the function.
1449      FunctionBBs.resize(Record[0]);
1450      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1451        FunctionBBs[i] = BasicBlock::Create("", F);
1452      CurBB = FunctionBBs[0];
1453      continue;
1454
1455    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1456      unsigned OpNum = 0;
1457      Value *LHS, *RHS;
1458      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1459          getValue(Record, OpNum, LHS->getType(), RHS) ||
1460          OpNum+1 != Record.size())
1461        return Error("Invalid BINOP record");
1462
1463      int Opc = GetDecodedBinaryOpcode(Record[OpNum], LHS->getType());
1464      if (Opc == -1) return Error("Invalid BINOP record");
1465      I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
1466      break;
1467    }
1468    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
1469      unsigned OpNum = 0;
1470      Value *Op;
1471      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1472          OpNum+2 != Record.size())
1473        return Error("Invalid CAST record");
1474
1475      const Type *ResTy = getTypeByID(Record[OpNum]);
1476      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
1477      if (Opc == -1 || ResTy == 0)
1478        return Error("Invalid CAST record");
1479      I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
1480      break;
1481    }
1482    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
1483      unsigned OpNum = 0;
1484      Value *BasePtr;
1485      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
1486        return Error("Invalid GEP record");
1487
1488      SmallVector<Value*, 16> GEPIdx;
1489      while (OpNum != Record.size()) {
1490        Value *Op;
1491        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1492          return Error("Invalid GEP record");
1493        GEPIdx.push_back(Op);
1494      }
1495
1496      I = GetElementPtrInst::Create(BasePtr, GEPIdx.begin(), GEPIdx.end());
1497      break;
1498    }
1499
1500    case bitc::FUNC_CODE_INST_EXTRACTVAL: {
1501                                       // EXTRACTVAL: [opty, opval, n x indices]
1502      unsigned OpNum = 0;
1503      Value *Agg;
1504      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
1505        return Error("Invalid EXTRACTVAL record");
1506
1507      SmallVector<unsigned, 4> EXTRACTVALIdx;
1508      for (unsigned RecSize = Record.size();
1509           OpNum != RecSize; ++OpNum) {
1510        uint64_t Index = Record[OpNum];
1511        if ((unsigned)Index != Index)
1512          return Error("Invalid EXTRACTVAL index");
1513        EXTRACTVALIdx.push_back((unsigned)Index);
1514      }
1515
1516      I = ExtractValueInst::Create(Agg,
1517                                   EXTRACTVALIdx.begin(), EXTRACTVALIdx.end());
1518      break;
1519    }
1520
1521    case bitc::FUNC_CODE_INST_INSERTVAL: {
1522                           // INSERTVAL: [opty, opval, opty, opval, n x indices]
1523      unsigned OpNum = 0;
1524      Value *Agg;
1525      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
1526        return Error("Invalid INSERTVAL record");
1527      Value *Val;
1528      if (getValueTypePair(Record, OpNum, NextValueNo, Val))
1529        return Error("Invalid INSERTVAL record");
1530
1531      SmallVector<unsigned, 4> INSERTVALIdx;
1532      for (unsigned RecSize = Record.size();
1533           OpNum != RecSize; ++OpNum) {
1534        uint64_t Index = Record[OpNum];
1535        if ((unsigned)Index != Index)
1536          return Error("Invalid INSERTVAL index");
1537        INSERTVALIdx.push_back((unsigned)Index);
1538      }
1539
1540      I = InsertValueInst::Create(Agg, Val,
1541                                  INSERTVALIdx.begin(), INSERTVALIdx.end());
1542      break;
1543    }
1544
1545    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
1546      // obsolete form of select
1547      // handles select i1 ... in old bitcode
1548      unsigned OpNum = 0;
1549      Value *TrueVal, *FalseVal, *Cond;
1550      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
1551          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
1552          getValue(Record, OpNum, Type::Int1Ty, Cond))
1553        return Error("Invalid SELECT record");
1554
1555      I = SelectInst::Create(Cond, TrueVal, FalseVal);
1556      break;
1557    }
1558
1559    case bitc::FUNC_CODE_INST_VSELECT: {// VSELECT: [ty,opval,opval,predty,pred]
1560      // new form of select
1561      // handles select i1 or select [N x i1]
1562      unsigned OpNum = 0;
1563      Value *TrueVal, *FalseVal, *Cond;
1564      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
1565          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
1566          getValueTypePair(Record, OpNum, NextValueNo, Cond))
1567        return Error("Invalid SELECT record");
1568
1569      // select condition can be either i1 or [N x i1]
1570      if (const VectorType* vector_type =
1571          dyn_cast<const VectorType>(Cond->getType())) {
1572        // expect <n x i1>
1573        if (vector_type->getElementType() != Type::Int1Ty)
1574          return Error("Invalid SELECT condition type");
1575      } else {
1576        // expect i1
1577        if (Cond->getType() != Type::Int1Ty)
1578          return Error("Invalid SELECT condition type");
1579      }
1580
1581      I = SelectInst::Create(Cond, TrueVal, FalseVal);
1582      break;
1583    }
1584
1585    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1586      unsigned OpNum = 0;
1587      Value *Vec, *Idx;
1588      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1589          getValue(Record, OpNum, Type::Int32Ty, Idx))
1590        return Error("Invalid EXTRACTELT record");
1591      I = new ExtractElementInst(Vec, Idx);
1592      break;
1593    }
1594
1595    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1596      unsigned OpNum = 0;
1597      Value *Vec, *Elt, *Idx;
1598      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1599          getValue(Record, OpNum,
1600                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
1601          getValue(Record, OpNum, Type::Int32Ty, Idx))
1602        return Error("Invalid INSERTELT record");
1603      I = InsertElementInst::Create(Vec, Elt, Idx);
1604      break;
1605    }
1606
1607    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
1608      unsigned OpNum = 0;
1609      Value *Vec1, *Vec2, *Mask;
1610      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
1611          getValue(Record, OpNum, Vec1->getType(), Vec2))
1612        return Error("Invalid SHUFFLEVEC record");
1613
1614      if (getValueTypePair(Record, OpNum, NextValueNo, Mask))
1615        return Error("Invalid SHUFFLEVEC record");
1616      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1617      break;
1618    }
1619
1620    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1621      // VFCmp/VICmp
1622      // or old form of ICmp/FCmp returning bool
1623      unsigned OpNum = 0;
1624      Value *LHS, *RHS;
1625      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1626          getValue(Record, OpNum, LHS->getType(), RHS) ||
1627          OpNum+1 != Record.size())
1628        return Error("Invalid CMP record");
1629
1630      if (LHS->getType()->isFloatingPoint())
1631        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1632      else if (!isa<VectorType>(LHS->getType()))
1633        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1634      else if (LHS->getType()->isFPOrFPVector())
1635        I = new VFCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1636      else
1637        I = new VICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1638      break;
1639    }
1640    case bitc::FUNC_CODE_INST_CMP2: { // CMP2: [opty, opval, opval, pred]
1641      // Fcmp/ICmp returning bool or vector of bool
1642      unsigned OpNum = 0;
1643      Value *LHS, *RHS;
1644      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1645          getValue(Record, OpNum, LHS->getType(), RHS) ||
1646          OpNum+1 != Record.size())
1647        return Error("Invalid CMP2 record");
1648
1649      if (LHS->getType()->isFPOrFPVector())
1650        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1651      else
1652        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1653      break;
1654    }
1655    case bitc::FUNC_CODE_INST_GETRESULT: { // GETRESULT: [ty, val, n]
1656      if (Record.size() != 2)
1657        return Error("Invalid GETRESULT record");
1658      unsigned OpNum = 0;
1659      Value *Op;
1660      getValueTypePair(Record, OpNum, NextValueNo, Op);
1661      unsigned Index = Record[1];
1662      I = ExtractValueInst::Create(Op, Index);
1663      break;
1664    }
1665
1666    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1667      {
1668        unsigned Size = Record.size();
1669        if (Size == 0) {
1670          I = ReturnInst::Create();
1671          break;
1672        }
1673
1674        unsigned OpNum = 0;
1675        SmallVector<Value *,4> Vs;
1676        do {
1677          Value *Op = NULL;
1678          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1679            return Error("Invalid RET record");
1680          Vs.push_back(Op);
1681        } while(OpNum != Record.size());
1682
1683        const Type *ReturnType = F->getReturnType();
1684        if (Vs.size() > 1 ||
1685            (isa<StructType>(ReturnType) &&
1686             (Vs.empty() || Vs[0]->getType() != ReturnType))) {
1687          Value *RV = UndefValue::get(ReturnType);
1688          for (unsigned i = 0, e = Vs.size(); i != e; ++i) {
1689            I = InsertValueInst::Create(RV, Vs[i], i, "mrv");
1690            CurBB->getInstList().push_back(I);
1691            ValueList.AssignValue(I, NextValueNo++);
1692            RV = I;
1693          }
1694          I = ReturnInst::Create(RV);
1695          break;
1696        }
1697
1698        I = ReturnInst::Create(Vs[0]);
1699        break;
1700      }
1701    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1702      if (Record.size() != 1 && Record.size() != 3)
1703        return Error("Invalid BR record");
1704      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1705      if (TrueDest == 0)
1706        return Error("Invalid BR record");
1707
1708      if (Record.size() == 1)
1709        I = BranchInst::Create(TrueDest);
1710      else {
1711        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1712        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1713        if (FalseDest == 0 || Cond == 0)
1714          return Error("Invalid BR record");
1715        I = BranchInst::Create(TrueDest, FalseDest, Cond);
1716      }
1717      break;
1718    }
1719    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1720      if (Record.size() < 3 || (Record.size() & 1) == 0)
1721        return Error("Invalid SWITCH record");
1722      const Type *OpTy = getTypeByID(Record[0]);
1723      Value *Cond = getFnValueByID(Record[1], OpTy);
1724      BasicBlock *Default = getBasicBlock(Record[2]);
1725      if (OpTy == 0 || Cond == 0 || Default == 0)
1726        return Error("Invalid SWITCH record");
1727      unsigned NumCases = (Record.size()-3)/2;
1728      SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
1729      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1730        ConstantInt *CaseVal =
1731          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1732        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1733        if (CaseVal == 0 || DestBB == 0) {
1734          delete SI;
1735          return Error("Invalid SWITCH record!");
1736        }
1737        SI->addCase(CaseVal, DestBB);
1738      }
1739      I = SI;
1740      break;
1741    }
1742
1743    case bitc::FUNC_CODE_INST_INVOKE: {
1744      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
1745      if (Record.size() < 4) return Error("Invalid INVOKE record");
1746      AttrListPtr PAL = getAttributes(Record[0]);
1747      unsigned CCInfo = Record[1];
1748      BasicBlock *NormalBB = getBasicBlock(Record[2]);
1749      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
1750
1751      unsigned OpNum = 4;
1752      Value *Callee;
1753      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1754        return Error("Invalid INVOKE record");
1755
1756      const PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
1757      const FunctionType *FTy = !CalleeTy ? 0 :
1758        dyn_cast<FunctionType>(CalleeTy->getElementType());
1759
1760      // Check that the right number of fixed parameters are here.
1761      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
1762          Record.size() < OpNum+FTy->getNumParams())
1763        return Error("Invalid INVOKE record");
1764
1765      SmallVector<Value*, 16> Ops;
1766      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1767        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1768        if (Ops.back() == 0) return Error("Invalid INVOKE record");
1769      }
1770
1771      if (!FTy->isVarArg()) {
1772        if (Record.size() != OpNum)
1773          return Error("Invalid INVOKE record");
1774      } else {
1775        // Read type/value pairs for varargs params.
1776        while (OpNum != Record.size()) {
1777          Value *Op;
1778          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1779            return Error("Invalid INVOKE record");
1780          Ops.push_back(Op);
1781        }
1782      }
1783
1784      I = InvokeInst::Create(Callee, NormalBB, UnwindBB,
1785                             Ops.begin(), Ops.end());
1786      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1787      cast<InvokeInst>(I)->setAttributes(PAL);
1788      break;
1789    }
1790    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1791      I = new UnwindInst();
1792      break;
1793    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1794      I = new UnreachableInst();
1795      break;
1796    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
1797      if (Record.size() < 1 || ((Record.size()-1)&1))
1798        return Error("Invalid PHI record");
1799      const Type *Ty = getTypeByID(Record[0]);
1800      if (!Ty) return Error("Invalid PHI record");
1801
1802      PHINode *PN = PHINode::Create(Ty);
1803      PN->reserveOperandSpace((Record.size()-1)/2);
1804
1805      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
1806        Value *V = getFnValueByID(Record[1+i], Ty);
1807        BasicBlock *BB = getBasicBlock(Record[2+i]);
1808        if (!V || !BB) return Error("Invalid PHI record");
1809        PN->addIncoming(V, BB);
1810      }
1811      I = PN;
1812      break;
1813    }
1814
1815    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1816      if (Record.size() < 3)
1817        return Error("Invalid MALLOC record");
1818      const PointerType *Ty =
1819        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1820      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1821      unsigned Align = Record[2];
1822      if (!Ty || !Size) return Error("Invalid MALLOC record");
1823      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1824      break;
1825    }
1826    case bitc::FUNC_CODE_INST_FREE: { // FREE: [op, opty]
1827      unsigned OpNum = 0;
1828      Value *Op;
1829      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1830          OpNum != Record.size())
1831        return Error("Invalid FREE record");
1832      I = new FreeInst(Op);
1833      break;
1834    }
1835    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1836      if (Record.size() < 3)
1837        return Error("Invalid ALLOCA record");
1838      const PointerType *Ty =
1839        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1840      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1841      unsigned Align = Record[2];
1842      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1843      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1844      break;
1845    }
1846    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1847      unsigned OpNum = 0;
1848      Value *Op;
1849      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1850          OpNum+2 != Record.size())
1851        return Error("Invalid LOAD record");
1852
1853      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1854      break;
1855    }
1856    case bitc::FUNC_CODE_INST_STORE2: { // STORE2:[ptrty, ptr, val, align, vol]
1857      unsigned OpNum = 0;
1858      Value *Val, *Ptr;
1859      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
1860          getValue(Record, OpNum,
1861                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
1862          OpNum+2 != Record.size())
1863        return Error("Invalid STORE record");
1864
1865      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1866      break;
1867    }
1868    case bitc::FUNC_CODE_INST_STORE: { // STORE:[val, valty, ptr, align, vol]
1869      // FIXME: Legacy form of store instruction. Should be removed in LLVM 3.0.
1870      unsigned OpNum = 0;
1871      Value *Val, *Ptr;
1872      if (getValueTypePair(Record, OpNum, NextValueNo, Val) ||
1873          getValue(Record, OpNum, PointerType::getUnqual(Val->getType()), Ptr)||
1874          OpNum+2 != Record.size())
1875        return Error("Invalid STORE record");
1876
1877      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1878      break;
1879    }
1880    case bitc::FUNC_CODE_INST_CALL: {
1881      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
1882      if (Record.size() < 3)
1883        return Error("Invalid CALL record");
1884
1885      AttrListPtr PAL = getAttributes(Record[0]);
1886      unsigned CCInfo = Record[1];
1887
1888      unsigned OpNum = 2;
1889      Value *Callee;
1890      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1891        return Error("Invalid CALL record");
1892
1893      const PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
1894      const FunctionType *FTy = 0;
1895      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1896      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
1897        return Error("Invalid CALL record");
1898
1899      SmallVector<Value*, 16> Args;
1900      // Read the fixed params.
1901      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1902        if (FTy->getParamType(i)->getTypeID()==Type::LabelTyID)
1903          Args.push_back(getBasicBlock(Record[OpNum]));
1904        else
1905          Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1906        if (Args.back() == 0) return Error("Invalid CALL record");
1907      }
1908
1909      // Read type/value pairs for varargs params.
1910      if (!FTy->isVarArg()) {
1911        if (OpNum != Record.size())
1912          return Error("Invalid CALL record");
1913      } else {
1914        while (OpNum != Record.size()) {
1915          Value *Op;
1916          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1917            return Error("Invalid CALL record");
1918          Args.push_back(Op);
1919        }
1920      }
1921
1922      I = CallInst::Create(Callee, Args.begin(), Args.end());
1923      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1924      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1925      cast<CallInst>(I)->setAttributes(PAL);
1926      break;
1927    }
1928    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1929      if (Record.size() < 3)
1930        return Error("Invalid VAARG record");
1931      const Type *OpTy = getTypeByID(Record[0]);
1932      Value *Op = getFnValueByID(Record[1], OpTy);
1933      const Type *ResTy = getTypeByID(Record[2]);
1934      if (!OpTy || !Op || !ResTy)
1935        return Error("Invalid VAARG record");
1936      I = new VAArgInst(Op, ResTy);
1937      break;
1938    }
1939    }
1940
1941    // Add instruction to end of current BB.  If there is no current BB, reject
1942    // this file.
1943    if (CurBB == 0) {
1944      delete I;
1945      return Error("Invalid instruction with no BB");
1946    }
1947    CurBB->getInstList().push_back(I);
1948
1949    // If this was a terminator instruction, move to the next block.
1950    if (isa<TerminatorInst>(I)) {
1951      ++CurBBNo;
1952      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1953    }
1954
1955    // Non-void values get registered in the value table for future use.
1956    if (I && I->getType() != Type::VoidTy)
1957      ValueList.AssignValue(I, NextValueNo++);
1958  }
1959
1960  // Check the function list for unresolved values.
1961  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1962    if (A->getParent() == 0) {
1963      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1964      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1965        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1966          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1967          delete A;
1968        }
1969      }
1970      return Error("Never resolved value found in function!");
1971    }
1972  }
1973
1974  // Trim the value list down to the size it was before we parsed this function.
1975  ValueList.shrinkTo(ModuleValueListSize);
1976  std::vector<BasicBlock*>().swap(FunctionBBs);
1977
1978  return false;
1979}
1980
1981//===----------------------------------------------------------------------===//
1982// ModuleProvider implementation
1983//===----------------------------------------------------------------------===//
1984
1985
1986bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1987  // If it already is material, ignore the request.
1988  if (!F->hasNotBeenReadFromBitcode()) return false;
1989
1990  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1991    DeferredFunctionInfo.find(F);
1992  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1993
1994  // Move the bit stream to the saved position of the deferred function body and
1995  // restore the real linkage type for the function.
1996  Stream.JumpToBit(DFII->second.first);
1997  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1998
1999  if (ParseFunctionBody(F)) {
2000    if (ErrInfo) *ErrInfo = ErrorString;
2001    return true;
2002  }
2003
2004  // Upgrade any old intrinsic calls in the function.
2005  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
2006       E = UpgradedIntrinsics.end(); I != E; ++I) {
2007    if (I->first != I->second) {
2008      for (Value::use_iterator UI = I->first->use_begin(),
2009           UE = I->first->use_end(); UI != UE; ) {
2010        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2011          UpgradeIntrinsicCall(CI, I->second);
2012      }
2013    }
2014  }
2015
2016  return false;
2017}
2018
2019void BitcodeReader::dematerializeFunction(Function *F) {
2020  // If this function isn't materialized, or if it is a proto, this is a noop.
2021  if (F->hasNotBeenReadFromBitcode() || F->isDeclaration())
2022    return;
2023
2024  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
2025
2026  // Just forget the function body, we can remat it later.
2027  F->deleteBody();
2028  F->setLinkage(GlobalValue::GhostLinkage);
2029}
2030
2031
2032Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
2033  for (DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
2034       DeferredFunctionInfo.begin(), E = DeferredFunctionInfo.end(); I != E;
2035       ++I) {
2036    Function *F = I->first;
2037    if (F->hasNotBeenReadFromBitcode() &&
2038        materializeFunction(F, ErrInfo))
2039      return 0;
2040  }
2041
2042  // Upgrade any intrinsic calls that slipped through (should not happen!) and
2043  // delete the old functions to clean up. We can't do this unless the entire
2044  // module is materialized because there could always be another function body
2045  // with calls to the old function.
2046  for (std::vector<std::pair<Function*, Function*> >::iterator I =
2047       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
2048    if (I->first != I->second) {
2049      for (Value::use_iterator UI = I->first->use_begin(),
2050           UE = I->first->use_end(); UI != UE; ) {
2051        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2052          UpgradeIntrinsicCall(CI, I->second);
2053      }
2054      if (!I->first->use_empty())
2055        I->first->replaceAllUsesWith(I->second);
2056      I->first->eraseFromParent();
2057    }
2058  }
2059  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
2060
2061  return TheModule;
2062}
2063
2064
2065/// This method is provided by the parent ModuleProvde class and overriden
2066/// here. It simply releases the module from its provided and frees up our
2067/// state.
2068/// @brief Release our hold on the generated module
2069Module *BitcodeReader::releaseModule(std::string *ErrInfo) {
2070  // Since we're losing control of this Module, we must hand it back complete
2071  Module *M = ModuleProvider::releaseModule(ErrInfo);
2072  FreeState();
2073  return M;
2074}
2075
2076
2077//===----------------------------------------------------------------------===//
2078// External interface
2079//===----------------------------------------------------------------------===//
2080
2081/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
2082///
2083ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
2084                                               std::string *ErrMsg) {
2085  BitcodeReader *R = new BitcodeReader(Buffer);
2086  if (R->ParseBitcode()) {
2087    if (ErrMsg)
2088      *ErrMsg = R->getErrorString();
2089
2090    // Don't let the BitcodeReader dtor delete 'Buffer'.
2091    R->releaseMemoryBuffer();
2092    delete R;
2093    return 0;
2094  }
2095  return R;
2096}
2097
2098/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
2099/// If an error occurs, return null and fill in *ErrMsg if non-null.
2100Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
2101  BitcodeReader *R;
2102  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
2103  if (!R) return 0;
2104
2105  // Read in the entire module.
2106  Module *M = R->materializeModule(ErrMsg);
2107
2108  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
2109  // there was an error.
2110  R->releaseMemoryBuffer();
2111
2112  // If there was no error, tell ModuleProvider not to delete it when its dtor
2113  // is run.
2114  if (M)
2115    M = R->releaseModule(ErrMsg);
2116
2117  delete R;
2118  return M;
2119}
2120