BitcodeReader.cpp revision c8f8a242e40b22871241e37a2b1a935c2db7fe1b 
1//===- BitcodeReader.cpp - Internal BitcodeReader implementation ----------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by Chris Lattner and is distributed under
6// the University of Illinois Open Source License.  See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This header defines the BitcodeReader class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Bitcode/ReaderWriter.h"
15#include "BitcodeReader.h"
16#include "llvm/Constants.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/Instructions.h"
19#include "llvm/Module.h"
20#include "llvm/ADT/SmallString.h"
21#include "llvm/Support/MathExtras.h"
22#include "llvm/Support/MemoryBuffer.h"
23using namespace llvm;
24
25BitcodeReader::~BitcodeReader() {
26  delete Buffer;
27}
28
29
30/// ConvertToString - Convert a string from a record into an std::string, return
31/// true on failure.
32template<typename StrTy>
33static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
34                            StrTy &Result) {
35  if (Record.size() < Idx+1 || Record.size() < Record[Idx]+Idx+1)
36    return true;
37
38  for (unsigned i = 0, e = Record[Idx]; i != e; ++i)
39    Result += (char)Record[Idx+i+1];
40  return false;
41}
42
43static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
44  switch (Val) {
45  default: // Map unknown/new linkages to external
46  case 0: return GlobalValue::ExternalLinkage;
47  case 1: return GlobalValue::WeakLinkage;
48  case 2: return GlobalValue::AppendingLinkage;
49  case 3: return GlobalValue::InternalLinkage;
50  case 4: return GlobalValue::LinkOnceLinkage;
51  case 5: return GlobalValue::DLLImportLinkage;
52  case 6: return GlobalValue::DLLExportLinkage;
53  case 7: return GlobalValue::ExternalWeakLinkage;
54  }
55}
56
57static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
58  switch (Val) {
59  default: // Map unknown visibilities to default.
60  case 0: return GlobalValue::DefaultVisibility;
61  case 1: return GlobalValue::HiddenVisibility;
62  case 2: return GlobalValue::ProtectedVisibility;
63  }
64}
65
66static int GetDecodedCastOpcode(unsigned Val) {
67  switch (Val) {
68  default: return -1;
69  case bitc::CAST_TRUNC   : return Instruction::Trunc;
70  case bitc::CAST_ZEXT    : return Instruction::ZExt;
71  case bitc::CAST_SEXT    : return Instruction::SExt;
72  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
73  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
74  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
75  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
76  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
77  case bitc::CAST_FPEXT   : return Instruction::FPExt;
78  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
79  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
80  case bitc::CAST_BITCAST : return Instruction::BitCast;
81  }
82}
83static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
84  switch (Val) {
85  default: return -1;
86  case bitc::BINOP_ADD:  return Instruction::Add;
87  case bitc::BINOP_SUB:  return Instruction::Sub;
88  case bitc::BINOP_MUL:  return Instruction::Mul;
89  case bitc::BINOP_UDIV: return Instruction::UDiv;
90  case bitc::BINOP_SDIV:
91    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
92  case bitc::BINOP_UREM: return Instruction::URem;
93  case bitc::BINOP_SREM:
94    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
95  case bitc::BINOP_SHL:  return Instruction::Shl;
96  case bitc::BINOP_LSHR: return Instruction::LShr;
97  case bitc::BINOP_ASHR: return Instruction::AShr;
98  case bitc::BINOP_AND:  return Instruction::And;
99  case bitc::BINOP_OR:   return Instruction::Or;
100  case bitc::BINOP_XOR:  return Instruction::Xor;
101  }
102}
103
104
105namespace {
106  /// @brief A class for maintaining the slot number definition
107  /// as a placeholder for the actual definition for forward constants defs.
108  class ConstantPlaceHolder : public ConstantExpr {
109    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
110    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
111  public:
112    Use Op;
113    ConstantPlaceHolder(const Type *Ty)
114      : ConstantExpr(Ty, Instruction::UserOp1, &Op, 1),
115        Op(UndefValue::get(Type::Int32Ty), this) {
116    }
117  };
118}
119
120Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
121                                                    const Type *Ty) {
122  if (Idx >= size()) {
123    // Insert a bunch of null values.
124    Uses.resize(Idx+1);
125    OperandList = &Uses[0];
126    NumOperands = Idx+1;
127  }
128
129  if (Value *V = Uses[Idx]) {
130    assert(Ty == V->getType() && "Type mismatch in constant table!");
131    return cast<Constant>(V);
132  }
133
134  // Create and return a placeholder, which will later be RAUW'd.
135  Constant *C = new ConstantPlaceHolder(Ty);
136  Uses[Idx].init(C, this);
137  return C;
138}
139
140Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
141  if (Idx >= size()) {
142    // Insert a bunch of null values.
143    Uses.resize(Idx+1);
144    OperandList = &Uses[0];
145    NumOperands = Idx+1;
146  }
147
148  if (Value *V = Uses[Idx]) {
149    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
150    return V;
151  }
152
153  // No type specified, must be invalid reference.
154  if (Ty == 0) return 0;
155
156  // Create and return a placeholder, which will later be RAUW'd.
157  Value *V = new Argument(Ty);
158  Uses[Idx].init(V, this);
159  return V;
160}
161
162
163const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
164  // If the TypeID is in range, return it.
165  if (ID < TypeList.size())
166    return TypeList[ID].get();
167  if (!isTypeTable) return 0;
168
169  // The type table allows forward references.  Push as many Opaque types as
170  // needed to get up to ID.
171  while (TypeList.size() <= ID)
172    TypeList.push_back(OpaqueType::get());
173  return TypeList.back().get();
174}
175
176bool BitcodeReader::ParseTypeTable() {
177  if (Stream.EnterSubBlock())
178    return Error("Malformed block record");
179
180  if (!TypeList.empty())
181    return Error("Multiple TYPE_BLOCKs found!");
182
183  SmallVector<uint64_t, 64> Record;
184  unsigned NumRecords = 0;
185
186  // Read all the records for this type table.
187  while (1) {
188    unsigned Code = Stream.ReadCode();
189    if (Code == bitc::END_BLOCK) {
190      if (NumRecords != TypeList.size())
191        return Error("Invalid type forward reference in TYPE_BLOCK");
192      if (Stream.ReadBlockEnd())
193        return Error("Error at end of type table block");
194      return false;
195    }
196
197    if (Code == bitc::ENTER_SUBBLOCK) {
198      // No known subblocks, always skip them.
199      Stream.ReadSubBlockID();
200      if (Stream.SkipBlock())
201        return Error("Malformed block record");
202      continue;
203    }
204
205    if (Code == bitc::DEFINE_ABBREV) {
206      Stream.ReadAbbrevRecord();
207      continue;
208    }
209
210    // Read a record.
211    Record.clear();
212    const Type *ResultTy = 0;
213    switch (Stream.ReadRecord(Code, Record)) {
214    default:  // Default behavior: unknown type.
215      ResultTy = 0;
216      break;
217    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
218      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
219      // type list.  This allows us to reserve space.
220      if (Record.size() < 1)
221        return Error("Invalid TYPE_CODE_NUMENTRY record");
222      TypeList.reserve(Record[0]);
223      continue;
224    case bitc::TYPE_CODE_META:      // TYPE_CODE_META: [metacode]...
225      // No metadata supported yet.
226      if (Record.size() < 1)
227        return Error("Invalid TYPE_CODE_META record");
228      continue;
229
230    case bitc::TYPE_CODE_VOID:      // VOID
231      ResultTy = Type::VoidTy;
232      break;
233    case bitc::TYPE_CODE_FLOAT:     // FLOAT
234      ResultTy = Type::FloatTy;
235      break;
236    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
237      ResultTy = Type::DoubleTy;
238      break;
239    case bitc::TYPE_CODE_LABEL:     // LABEL
240      ResultTy = Type::LabelTy;
241      break;
242    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
243      ResultTy = 0;
244      break;
245    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
246      if (Record.size() < 1)
247        return Error("Invalid Integer type record");
248
249      ResultTy = IntegerType::get(Record[0]);
250      break;
251    case bitc::TYPE_CODE_POINTER:   // POINTER: [pointee type]
252      if (Record.size() < 1)
253        return Error("Invalid POINTER type record");
254      ResultTy = PointerType::get(getTypeByID(Record[0], true));
255      break;
256    case bitc::TYPE_CODE_FUNCTION: {
257      // FUNCTION: [vararg, retty, #pararms, paramty N]
258      if (Record.size() < 3 || Record.size() < Record[2]+3)
259        return Error("Invalid FUNCTION type record");
260      std::vector<const Type*> ArgTys;
261      for (unsigned i = 0, e = Record[2]; i != e; ++i)
262        ArgTys.push_back(getTypeByID(Record[3+i], true));
263
264      // FIXME: PARAM TYS.
265      ResultTy = FunctionType::get(getTypeByID(Record[1], true), ArgTys,
266                                   Record[0]);
267      break;
268    }
269    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, #elts, eltty x N]
270      if (Record.size() < 2 || Record.size() < Record[1]+2)
271        return Error("Invalid STRUCT type record");
272      std::vector<const Type*> EltTys;
273      for (unsigned i = 0, e = Record[1]; i != e; ++i)
274        EltTys.push_back(getTypeByID(Record[2+i], true));
275      ResultTy = StructType::get(EltTys, Record[0]);
276      break;
277    }
278    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
279      if (Record.size() < 2)
280        return Error("Invalid ARRAY type record");
281      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
282      break;
283    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
284      if (Record.size() < 2)
285        return Error("Invalid VECTOR type record");
286      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
287      break;
288    }
289
290    if (NumRecords == TypeList.size()) {
291      // If this is a new type slot, just append it.
292      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
293      ++NumRecords;
294    } else if (ResultTy == 0) {
295      // Otherwise, this was forward referenced, so an opaque type was created,
296      // but the result type is actually just an opaque.  Leave the one we
297      // created previously.
298      ++NumRecords;
299    } else {
300      // Otherwise, this was forward referenced, so an opaque type was created.
301      // Resolve the opaque type to the real type now.
302      assert(NumRecords < TypeList.size() && "Typelist imbalance");
303      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
304
305      // Don't directly push the new type on the Tab. Instead we want to replace
306      // the opaque type we previously inserted with the new concrete value. The
307      // refinement from the abstract (opaque) type to the new type causes all
308      // uses of the abstract type to use the concrete type (NewTy). This will
309      // also cause the opaque type to be deleted.
310      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
311
312      // This should have replaced the old opaque type with the new type in the
313      // value table... or with a preexisting type that was already in the
314      // system.  Let's just make sure it did.
315      assert(TypeList[NumRecords-1].get() != OldTy &&
316             "refineAbstractType didn't work!");
317    }
318  }
319}
320
321
322bool BitcodeReader::ParseTypeSymbolTable() {
323  if (Stream.EnterSubBlock())
324    return Error("Malformed block record");
325
326  SmallVector<uint64_t, 64> Record;
327
328  // Read all the records for this type table.
329  std::string TypeName;
330  while (1) {
331    unsigned Code = Stream.ReadCode();
332    if (Code == bitc::END_BLOCK) {
333      if (Stream.ReadBlockEnd())
334        return Error("Error at end of type symbol table block");
335      return false;
336    }
337
338    if (Code == bitc::ENTER_SUBBLOCK) {
339      // No known subblocks, always skip them.
340      Stream.ReadSubBlockID();
341      if (Stream.SkipBlock())
342        return Error("Malformed block record");
343      continue;
344    }
345
346    if (Code == bitc::DEFINE_ABBREV) {
347      Stream.ReadAbbrevRecord();
348      continue;
349    }
350
351    // Read a record.
352    Record.clear();
353    switch (Stream.ReadRecord(Code, Record)) {
354    default:  // Default behavior: unknown type.
355      break;
356    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namelen, namechar x N]
357      if (ConvertToString(Record, 1, TypeName))
358        return Error("Invalid TST_ENTRY record");
359      unsigned TypeID = Record[0];
360      if (TypeID >= TypeList.size())
361        return Error("Invalid Type ID in TST_ENTRY record");
362
363      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
364      TypeName.clear();
365      break;
366    }
367  }
368}
369
370bool BitcodeReader::ParseValueSymbolTable() {
371  if (Stream.EnterSubBlock())
372    return Error("Malformed block record");
373
374  SmallVector<uint64_t, 64> Record;
375
376  // Read all the records for this value table.
377  SmallString<128> ValueName;
378  while (1) {
379    unsigned Code = Stream.ReadCode();
380    if (Code == bitc::END_BLOCK) {
381      if (Stream.ReadBlockEnd())
382        return Error("Error at end of value symbol table block");
383      return false;
384    }
385    if (Code == bitc::ENTER_SUBBLOCK) {
386      // No known subblocks, always skip them.
387      Stream.ReadSubBlockID();
388      if (Stream.SkipBlock())
389        return Error("Malformed block record");
390      continue;
391    }
392
393    if (Code == bitc::DEFINE_ABBREV) {
394      Stream.ReadAbbrevRecord();
395      continue;
396    }
397
398    // Read a record.
399    Record.clear();
400    switch (Stream.ReadRecord(Code, Record)) {
401    default:  // Default behavior: unknown type.
402      break;
403    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namelen, namechar x N]
404      if (ConvertToString(Record, 1, ValueName))
405        return Error("Invalid TST_ENTRY record");
406      unsigned ValueID = Record[0];
407      if (ValueID >= ValueList.size())
408        return Error("Invalid Value ID in VST_ENTRY record");
409      Value *V = ValueList[ValueID];
410
411      V->setName(&ValueName[0], ValueName.size());
412      ValueName.clear();
413      break;
414    }
415    case bitc::VST_CODE_BBENTRY: {
416      if (ConvertToString(Record, 1, ValueName))
417        return Error("Invalid VST_BBENTRY record");
418      BasicBlock *BB = getBasicBlock(Record[0]);
419      if (BB == 0)
420        return Error("Invalid BB ID in VST_BBENTRY record");
421
422      BB->setName(&ValueName[0], ValueName.size());
423      ValueName.clear();
424      break;
425    }
426    }
427  }
428}
429
430/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
431/// the LSB for dense VBR encoding.
432static uint64_t DecodeSignRotatedValue(uint64_t V) {
433  if ((V & 1) == 0)
434    return V >> 1;
435  if (V != 1)
436    return -(V >> 1);
437  // There is no such thing as -0 with integers.  "-0" really means MININT.
438  return 1ULL << 63;
439}
440
441/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
442/// values and aliases that we can.
443bool BitcodeReader::ResolveGlobalAndAliasInits() {
444  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
445  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
446
447  GlobalInitWorklist.swap(GlobalInits);
448  AliasInitWorklist.swap(AliasInits);
449
450  while (!GlobalInitWorklist.empty()) {
451    unsigned ValID = GlobalInitWorklist.back().second;
452    if (ValID >= ValueList.size()) {
453      // Not ready to resolve this yet, it requires something later in the file.
454      GlobalInits.push_back(GlobalInitWorklist.back());
455    } else {
456      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
457        GlobalInitWorklist.back().first->setInitializer(C);
458      else
459        return Error("Global variable initializer is not a constant!");
460    }
461    GlobalInitWorklist.pop_back();
462  }
463
464  while (!AliasInitWorklist.empty()) {
465    unsigned ValID = AliasInitWorklist.back().second;
466    if (ValID >= ValueList.size()) {
467      AliasInits.push_back(AliasInitWorklist.back());
468    } else {
469      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
470        AliasInitWorklist.back().first->setAliasee(C);
471      else
472        return Error("Alias initializer is not a constant!");
473    }
474    AliasInitWorklist.pop_back();
475  }
476  return false;
477}
478
479
480bool BitcodeReader::ParseConstants() {
481  if (Stream.EnterSubBlock())
482    return Error("Malformed block record");
483
484  SmallVector<uint64_t, 64> Record;
485
486  // Read all the records for this value table.
487  const Type *CurTy = Type::Int32Ty;
488  unsigned NextCstNo = ValueList.size();
489  while (1) {
490    unsigned Code = Stream.ReadCode();
491    if (Code == bitc::END_BLOCK) {
492      if (NextCstNo != ValueList.size())
493        return Error("Invalid constant reference!");
494
495      if (Stream.ReadBlockEnd())
496        return Error("Error at end of constants block");
497      return false;
498    }
499
500    if (Code == bitc::ENTER_SUBBLOCK) {
501      // No known subblocks, always skip them.
502      Stream.ReadSubBlockID();
503      if (Stream.SkipBlock())
504        return Error("Malformed block record");
505      continue;
506    }
507
508    if (Code == bitc::DEFINE_ABBREV) {
509      Stream.ReadAbbrevRecord();
510      continue;
511    }
512
513    // Read a record.
514    Record.clear();
515    Value *V = 0;
516    switch (Stream.ReadRecord(Code, Record)) {
517    default:  // Default behavior: unknown constant
518    case bitc::CST_CODE_UNDEF:     // UNDEF
519      V = UndefValue::get(CurTy);
520      break;
521    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
522      if (Record.empty())
523        return Error("Malformed CST_SETTYPE record");
524      if (Record[0] >= TypeList.size())
525        return Error("Invalid Type ID in CST_SETTYPE record");
526      CurTy = TypeList[Record[0]];
527      continue;  // Skip the ValueList manipulation.
528    case bitc::CST_CODE_NULL:      // NULL
529      V = Constant::getNullValue(CurTy);
530      break;
531    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
532      if (!isa<IntegerType>(CurTy) || Record.empty())
533        return Error("Invalid CST_INTEGER record");
534      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
535      break;
536    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n, n x intval]
537      if (!isa<IntegerType>(CurTy) || Record.empty() ||
538          Record.size() < Record[0]+1)
539        return Error("Invalid WIDE_INTEGER record");
540
541      unsigned NumWords = Record[0];
542      SmallVector<uint64_t, 8> Words;
543      Words.resize(NumWords);
544      for (unsigned i = 0; i != NumWords; ++i)
545        Words[i] = DecodeSignRotatedValue(Record[i+1]);
546      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
547                                 NumWords, &Words[0]));
548      break;
549    }
550    case bitc::CST_CODE_FLOAT:     // FLOAT: [fpval]
551      if (Record.empty())
552        return Error("Invalid FLOAT record");
553      if (CurTy == Type::FloatTy)
554        V = ConstantFP::get(CurTy, BitsToFloat(Record[0]));
555      else if (CurTy == Type::DoubleTy)
556        V = ConstantFP::get(CurTy, BitsToDouble(Record[0]));
557      else
558        V = UndefValue::get(CurTy);
559      break;
560
561    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n, n x value number]
562      if (Record.empty() || Record.size() < Record[0]+1)
563        return Error("Invalid CST_AGGREGATE record");
564
565      unsigned Size = Record[0];
566      std::vector<Constant*> Elts;
567
568      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
569        for (unsigned i = 0; i != Size; ++i)
570          Elts.push_back(ValueList.getConstantFwdRef(Record[i+1],
571                                                     STy->getElementType(i)));
572        V = ConstantStruct::get(STy, Elts);
573      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
574        const Type *EltTy = ATy->getElementType();
575        for (unsigned i = 0; i != Size; ++i)
576          Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], EltTy));
577        V = ConstantArray::get(ATy, Elts);
578      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
579        const Type *EltTy = VTy->getElementType();
580        for (unsigned i = 0; i != Size; ++i)
581          Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], EltTy));
582        V = ConstantVector::get(Elts);
583      } else {
584        V = UndefValue::get(CurTy);
585      }
586      break;
587    }
588
589    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
590      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
591      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
592      if (Opc < 0) {
593        V = UndefValue::get(CurTy);  // Unknown binop.
594      } else {
595        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
596        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
597        V = ConstantExpr::get(Opc, LHS, RHS);
598      }
599      break;
600    }
601    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
602      if (Record.size() < 3) return Error("Invalid CE_CAST record");
603      int Opc = GetDecodedCastOpcode(Record[0]);
604      if (Opc < 0) {
605        V = UndefValue::get(CurTy);  // Unknown cast.
606      } else {
607        const Type *OpTy = getTypeByID(Record[1]);
608        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
609        V = ConstantExpr::getCast(Opc, Op, CurTy);
610      }
611      break;
612    }
613    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
614      if ((Record.size() & 1) == 0) return Error("Invalid CE_GEP record");
615      SmallVector<Constant*, 16> Elts;
616      for (unsigned i = 1, e = Record.size(); i != e; i += 2) {
617        const Type *ElTy = getTypeByID(Record[i]);
618        if (!ElTy) return Error("Invalid CE_GEP record");
619        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
620      }
621      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
622      break;
623    }
624    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
625      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
626      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
627                                                              Type::Int1Ty),
628                                  ValueList.getConstantFwdRef(Record[1],CurTy),
629                                  ValueList.getConstantFwdRef(Record[2],CurTy));
630      break;
631    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
632      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
633      const VectorType *OpTy =
634        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
635      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
636      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
637      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
638                                                  OpTy->getElementType());
639      V = ConstantExpr::getExtractElement(Op0, Op1);
640      break;
641    }
642    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
643      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
644      if (Record.size() < 3 || OpTy == 0)
645        return Error("Invalid CE_INSERTELT record");
646      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
647      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
648                                                  OpTy->getElementType());
649      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
650      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
651      break;
652    }
653    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
654      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
655      if (Record.size() < 3 || OpTy == 0)
656        return Error("Invalid CE_INSERTELT record");
657      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
658      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
659      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
660      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
661      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
662      break;
663    }
664    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
665      if (Record.size() < 4) return Error("Invalid CE_CMP record");
666      const Type *OpTy = getTypeByID(Record[0]);
667      if (OpTy == 0) return Error("Invalid CE_CMP record");
668      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
669      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
670
671      if (OpTy->isFloatingPoint())
672        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
673      else
674        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
675      break;
676    }
677    }
678
679    ValueList.AssignValue(V, NextCstNo);
680    ++NextCstNo;
681  }
682}
683
684/// RememberAndSkipFunctionBody - When we see the block for a function body,
685/// remember where it is and then skip it.  This lets us lazily deserialize the
686/// functions.
687bool BitcodeReader::RememberAndSkipFunctionBody() {
688  // Get the function we are talking about.
689  if (FunctionsWithBodies.empty())
690    return Error("Insufficient function protos");
691
692  Function *Fn = FunctionsWithBodies.back();
693  FunctionsWithBodies.pop_back();
694
695  // Save the current stream state.
696  uint64_t CurBit = Stream.GetCurrentBitNo();
697  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
698
699  // Set the functions linkage to GhostLinkage so we know it is lazily
700  // deserialized.
701  Fn->setLinkage(GlobalValue::GhostLinkage);
702
703  // Skip over the function block for now.
704  if (Stream.SkipBlock())
705    return Error("Malformed block record");
706  return false;
707}
708
709bool BitcodeReader::ParseModule(const std::string &ModuleID) {
710  // Reject multiple MODULE_BLOCK's in a single bitstream.
711  if (TheModule)
712    return Error("Multiple MODULE_BLOCKs in same stream");
713
714  if (Stream.EnterSubBlock())
715    return Error("Malformed block record");
716
717  // Otherwise, create the module.
718  TheModule = new Module(ModuleID);
719
720  SmallVector<uint64_t, 64> Record;
721  std::vector<std::string> SectionTable;
722
723  // Read all the records for this module.
724  while (!Stream.AtEndOfStream()) {
725    unsigned Code = Stream.ReadCode();
726    if (Code == bitc::END_BLOCK) {
727      if (Stream.ReadBlockEnd())
728        return Error("Error at end of module block");
729
730      // Patch the initializers for globals and aliases up.
731      ResolveGlobalAndAliasInits();
732      if (!GlobalInits.empty() || !AliasInits.empty())
733        return Error("Malformed global initializer set");
734      if (!FunctionsWithBodies.empty())
735        return Error("Too few function bodies found");
736
737      // Force deallocation of memory for these vectors to favor the client that
738      // want lazy deserialization.
739      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
740      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
741      std::vector<Function*>().swap(FunctionsWithBodies);
742      return false;
743    }
744
745    if (Code == bitc::ENTER_SUBBLOCK) {
746      switch (Stream.ReadSubBlockID()) {
747      default:  // Skip unknown content.
748        if (Stream.SkipBlock())
749          return Error("Malformed block record");
750        break;
751      case bitc::TYPE_BLOCK_ID:
752        if (ParseTypeTable())
753          return true;
754        break;
755      case bitc::TYPE_SYMTAB_BLOCK_ID:
756        if (ParseTypeSymbolTable())
757          return true;
758        break;
759      case bitc::VALUE_SYMTAB_BLOCK_ID:
760        if (ParseValueSymbolTable())
761          return true;
762        break;
763      case bitc::CONSTANTS_BLOCK_ID:
764        if (ParseConstants() || ResolveGlobalAndAliasInits())
765          return true;
766        break;
767      case bitc::FUNCTION_BLOCK_ID:
768        // If this is the first function body we've seen, reverse the
769        // FunctionsWithBodies list.
770        if (!HasReversedFunctionsWithBodies) {
771          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
772          HasReversedFunctionsWithBodies = true;
773        }
774
775        if (RememberAndSkipFunctionBody())
776          return true;
777        break;
778      }
779      continue;
780    }
781
782    if (Code == bitc::DEFINE_ABBREV) {
783      Stream.ReadAbbrevRecord();
784      continue;
785    }
786
787    // Read a record.
788    switch (Stream.ReadRecord(Code, Record)) {
789    default: break;  // Default behavior, ignore unknown content.
790    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
791      if (Record.size() < 1)
792        return Error("Malformed MODULE_CODE_VERSION");
793      // Only version #0 is supported so far.
794      if (Record[0] != 0)
795        return Error("Unknown bitstream version!");
796      break;
797    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strlen, strchr x N]
798      std::string S;
799      if (ConvertToString(Record, 0, S))
800        return Error("Invalid MODULE_CODE_TRIPLE record");
801      TheModule->setTargetTriple(S);
802      break;
803    }
804    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strlen, strchr x N]
805      std::string S;
806      if (ConvertToString(Record, 0, S))
807        return Error("Invalid MODULE_CODE_DATALAYOUT record");
808      TheModule->setDataLayout(S);
809      break;
810    }
811    case bitc::MODULE_CODE_ASM: {  // ASM: [strlen, strchr x N]
812      std::string S;
813      if (ConvertToString(Record, 0, S))
814        return Error("Invalid MODULE_CODE_ASM record");
815      TheModule->setModuleInlineAsm(S);
816      break;
817    }
818    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strlen, strchr x N]
819      std::string S;
820      if (ConvertToString(Record, 0, S))
821        return Error("Invalid MODULE_CODE_DEPLIB record");
822      TheModule->addLibrary(S);
823      break;
824    }
825    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strlen, strchr x N]
826      std::string S;
827      if (ConvertToString(Record, 0, S))
828        return Error("Invalid MODULE_CODE_SECTIONNAME record");
829      SectionTable.push_back(S);
830      break;
831    }
832    // GLOBALVAR: [type, isconst, initid,
833    //             linkage, alignment, section, visibility, threadlocal]
834    case bitc::MODULE_CODE_GLOBALVAR: {
835      if (Record.size() < 6)
836        return Error("Invalid MODULE_CODE_GLOBALVAR record");
837      const Type *Ty = getTypeByID(Record[0]);
838      if (!isa<PointerType>(Ty))
839        return Error("Global not a pointer type!");
840      Ty = cast<PointerType>(Ty)->getElementType();
841
842      bool isConstant = Record[1];
843      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
844      unsigned Alignment = (1 << Record[4]) >> 1;
845      std::string Section;
846      if (Record[5]) {
847        if (Record[5]-1 >= SectionTable.size())
848          return Error("Invalid section ID");
849        Section = SectionTable[Record[5]-1];
850      }
851      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
852      if (Record.size() >= 6) Visibility = GetDecodedVisibility(Record[6]);
853      bool isThreadLocal = false;
854      if (Record.size() >= 7) isThreadLocal = Record[7];
855
856      GlobalVariable *NewGV =
857        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule);
858      NewGV->setAlignment(Alignment);
859      if (!Section.empty())
860        NewGV->setSection(Section);
861      NewGV->setVisibility(Visibility);
862      NewGV->setThreadLocal(isThreadLocal);
863
864      ValueList.push_back(NewGV);
865
866      // Remember which value to use for the global initializer.
867      if (unsigned InitID = Record[2])
868        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
869      break;
870    }
871    // FUNCTION:  [type, callingconv, isproto, linkage, alignment, section,
872    //             visibility]
873    case bitc::MODULE_CODE_FUNCTION: {
874      if (Record.size() < 7)
875        return Error("Invalid MODULE_CODE_FUNCTION record");
876      const Type *Ty = getTypeByID(Record[0]);
877      if (!isa<PointerType>(Ty))
878        return Error("Function not a pointer type!");
879      const FunctionType *FTy =
880        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
881      if (!FTy)
882        return Error("Function not a pointer to function type!");
883
884      Function *Func = new Function(FTy, GlobalValue::ExternalLinkage,
885                                    "", TheModule);
886
887      Func->setCallingConv(Record[1]);
888      bool isProto = Record[2];
889      Func->setLinkage(GetDecodedLinkage(Record[3]));
890      Func->setAlignment((1 << Record[4]) >> 1);
891      if (Record[5]) {
892        if (Record[5]-1 >= SectionTable.size())
893          return Error("Invalid section ID");
894        Func->setSection(SectionTable[Record[5]-1]);
895      }
896      Func->setVisibility(GetDecodedVisibility(Record[6]));
897
898      ValueList.push_back(Func);
899
900      // If this is a function with a body, remember the prototype we are
901      // creating now, so that we can match up the body with them later.
902      if (!isProto)
903        FunctionsWithBodies.push_back(Func);
904      break;
905    }
906    // ALIAS: [alias type, aliasee val#, linkage]
907    case bitc::MODULE_CODE_ALIAS: {
908      if (Record.size() < 3)
909        return Error("Invalid MODULE_ALIAS record");
910      const Type *Ty = getTypeByID(Record[0]);
911      if (!isa<PointerType>(Ty))
912        return Error("Function not a pointer type!");
913
914      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
915                                           "", 0, TheModule);
916      ValueList.push_back(NewGA);
917      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
918      break;
919    }
920    /// MODULE_CODE_PURGEVALS: [numvals]
921    case bitc::MODULE_CODE_PURGEVALS:
922      // Trim down the value list to the specified size.
923      if (Record.size() < 1 || Record[0] > ValueList.size())
924        return Error("Invalid MODULE_PURGEVALS record");
925      ValueList.shrinkTo(Record[0]);
926      break;
927    }
928    Record.clear();
929  }
930
931  return Error("Premature end of bitstream");
932}
933
934
935bool BitcodeReader::ParseBitcode() {
936  TheModule = 0;
937
938  if (Buffer->getBufferSize() & 3)
939    return Error("Bitcode stream should be a multiple of 4 bytes in length");
940
941  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
942  Stream.init(BufPtr, BufPtr+Buffer->getBufferSize());
943
944  // Sniff for the signature.
945  if (Stream.Read(8) != 'B' ||
946      Stream.Read(8) != 'C' ||
947      Stream.Read(4) != 0x0 ||
948      Stream.Read(4) != 0xC ||
949      Stream.Read(4) != 0xE ||
950      Stream.Read(4) != 0xD)
951    return Error("Invalid bitcode signature");
952
953  // We expect a number of well-defined blocks, though we don't necessarily
954  // need to understand them all.
955  while (!Stream.AtEndOfStream()) {
956    unsigned Code = Stream.ReadCode();
957
958    if (Code != bitc::ENTER_SUBBLOCK)
959      return Error("Invalid record at top-level");
960
961    unsigned BlockID = Stream.ReadSubBlockID();
962
963    // We only know the MODULE subblock ID.
964    if (BlockID == bitc::MODULE_BLOCK_ID) {
965      if (ParseModule(Buffer->getBufferIdentifier()))
966        return true;
967    } else if (Stream.SkipBlock()) {
968      return Error("Malformed block record");
969    }
970  }
971
972  return false;
973}
974
975
976bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
977  // If it already is material, ignore the request.
978  if (!F->hasNotBeenReadFromBytecode()) return false;
979
980  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
981    DeferredFunctionInfo.find(F);
982  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
983
984  // Move the bit stream to the saved position of the deferred function body and
985  // restore the real linkage type for the function.
986  Stream.JumpToBit(DFII->second.first);
987  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
988  DeferredFunctionInfo.erase(DFII);
989
990  if (ParseFunctionBody(F)) {
991    if (ErrInfo) *ErrInfo = ErrorString;
992    return true;
993  }
994
995  return false;
996}
997
998Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
999  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1000    DeferredFunctionInfo.begin();
1001  while (!DeferredFunctionInfo.empty()) {
1002    Function *F = (*I++).first;
1003    assert(F->hasNotBeenReadFromBytecode() &&
1004           "Deserialized function found in map!");
1005    if (materializeFunction(F, ErrInfo))
1006      return 0;
1007  }
1008  return TheModule;
1009}
1010
1011
1012/// ParseFunctionBody - Lazily parse the specified function body block.
1013bool BitcodeReader::ParseFunctionBody(Function *F) {
1014  if (Stream.EnterSubBlock())
1015    return Error("Malformed block record");
1016
1017  unsigned ModuleValueListSize = ValueList.size();
1018
1019  // Add all the function arguments to the value table.
1020  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1021    ValueList.push_back(I);
1022
1023  unsigned NextValueNo = ValueList.size();
1024  BasicBlock *CurBB = 0;
1025  unsigned CurBBNo = 0;
1026
1027  // Read all the records.
1028  SmallVector<uint64_t, 64> Record;
1029  while (1) {
1030    unsigned Code = Stream.ReadCode();
1031    if (Code == bitc::END_BLOCK) {
1032      if (Stream.ReadBlockEnd())
1033        return Error("Error at end of function block");
1034      break;
1035    }
1036
1037    if (Code == bitc::ENTER_SUBBLOCK) {
1038      switch (Stream.ReadSubBlockID()) {
1039      default:  // Skip unknown content.
1040        if (Stream.SkipBlock())
1041          return Error("Malformed block record");
1042        break;
1043      case bitc::CONSTANTS_BLOCK_ID:
1044        if (ParseConstants()) return true;
1045        NextValueNo = ValueList.size();
1046        break;
1047      case bitc::VALUE_SYMTAB_BLOCK_ID:
1048        if (ParseValueSymbolTable()) return true;
1049        break;
1050      }
1051      continue;
1052    }
1053
1054    if (Code == bitc::DEFINE_ABBREV) {
1055      Stream.ReadAbbrevRecord();
1056      continue;
1057    }
1058
1059    // Read a record.
1060    Record.clear();
1061    Instruction *I = 0;
1062    switch (Stream.ReadRecord(Code, Record)) {
1063    default: // Default behavior: reject
1064      return Error("Unknown instruction");
1065    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1066      if (Record.size() < 1 || Record[0] == 0)
1067        return Error("Invalid DECLAREBLOCKS record");
1068      // Create all the basic blocks for the function.
1069      FunctionBBs.resize(Record[0]);
1070      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1071        FunctionBBs[i] = new BasicBlock("", F);
1072      CurBB = FunctionBBs[0];
1073      continue;
1074
1075    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opcode, ty, opval, opval]
1076      if (Record.size() < 4) return Error("Invalid BINOP record");
1077      const Type *Ty = getTypeByID(Record[1]);
1078      int Opc = GetDecodedBinaryOpcode(Record[0], Ty);
1079      Value *LHS = getFnValueByID(Record[2], Ty);
1080      Value *RHS = getFnValueByID(Record[3], Ty);
1081      if (Opc == -1 || Ty == 0 || LHS == 0 || RHS == 0)
1082         return Error("Invalid BINOP record");
1083      I = BinaryOperator::create((Instruction::BinaryOps)Opc, LHS, RHS);
1084      break;
1085    }
1086    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opcode, ty, opty, opval]
1087      if (Record.size() < 4) return Error("Invalid CAST record");
1088      int Opc = GetDecodedCastOpcode(Record[0]);
1089      const Type *ResTy = getTypeByID(Record[1]);
1090      const Type *OpTy = getTypeByID(Record[2]);
1091      Value *Op = getFnValueByID(Record[3], OpTy);
1092      if (Opc == -1 || ResTy == 0 || OpTy == 0 || Op == 0)
1093        return Error("Invalid CAST record");
1094      I = CastInst::create((Instruction::CastOps)Opc, Op, ResTy);
1095      break;
1096    }
1097    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n, n x operands]
1098      if (Record.size() < 2 || (Record.size() & 1))
1099        return Error("Invalid GEP record");
1100      const Type *OpTy = getTypeByID(Record[0]);
1101      Value *Op = getFnValueByID(Record[1], OpTy);
1102      if (OpTy == 0 || Op == 0)
1103        return Error("Invalid GEP record");
1104
1105      SmallVector<Value*, 16> GEPIdx;
1106      for (unsigned i = 1, e = Record.size()/2; i != e; ++i) {
1107        const Type *IdxTy = getTypeByID(Record[i*2]);
1108        Value *Idx = getFnValueByID(Record[i*2+1], IdxTy);
1109        if (IdxTy == 0 || Idx == 0)
1110          return Error("Invalid GEP record");
1111        GEPIdx.push_back(Idx);
1112      }
1113
1114      I = new GetElementPtrInst(Op, &GEPIdx[0], GEPIdx.size());
1115      break;
1116    }
1117
1118    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [ty, opval, opval, opval]
1119      if (Record.size() < 4) return Error("Invalid SELECT record");
1120      const Type *Ty = getTypeByID(Record[0]);
1121      Value *Cond = getFnValueByID(Record[1], Type::Int1Ty);
1122      Value *LHS = getFnValueByID(Record[2], Ty);
1123      Value *RHS = getFnValueByID(Record[3], Ty);
1124      if (Ty == 0 || Cond == 0 || LHS == 0 || RHS == 0)
1125        return Error("Invalid SELECT record");
1126      I = new SelectInst(Cond, LHS, RHS);
1127      break;
1128    }
1129
1130    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1131      if (Record.size() < 3) return Error("Invalid EXTRACTELT record");
1132      const Type *OpTy = getTypeByID(Record[0]);
1133      Value *Vec = getFnValueByID(Record[1], OpTy);
1134      Value *Idx = getFnValueByID(Record[2], Type::Int32Ty);
1135      if (OpTy == 0 || Vec == 0 || Idx == 0)
1136        return Error("Invalid EXTRACTELT record");
1137      I = new ExtractElementInst(Vec, Idx);
1138      break;
1139    }
1140
1141    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1142      if (Record.size() < 4) return Error("Invalid INSERTELT record");
1143      const VectorType *OpTy =
1144        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1145      if (OpTy == 0) return Error("Invalid INSERTELT record");
1146      Value *Vec = getFnValueByID(Record[1], OpTy);
1147      Value *Elt = getFnValueByID(Record[2], OpTy->getElementType());
1148      Value *Idx = getFnValueByID(Record[3], Type::Int32Ty);
1149      if (Vec == 0 || Elt == 0 || Idx == 0)
1150        return Error("Invalid INSERTELT record");
1151      I = new InsertElementInst(Vec, Elt, Idx);
1152      break;
1153    }
1154
1155    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [ty,opval,opval,opval]
1156      if (Record.size() < 4) return Error("Invalid SHUFFLEVEC record");
1157      const VectorType *OpTy =
1158        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1159      if (OpTy == 0) return Error("Invalid SHUFFLEVEC record");
1160      Value *Vec1 = getFnValueByID(Record[1], OpTy);
1161      Value *Vec2 = getFnValueByID(Record[2], OpTy);
1162      Value *Mask = getFnValueByID(Record[3],
1163                                   VectorType::get(Type::Int32Ty,
1164                                                   OpTy->getNumElements()));
1165      if (Vec1 == 0 || Vec2 == 0 || Mask == 0)
1166        return Error("Invalid SHUFFLEVEC record");
1167      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1168      break;
1169    }
1170
1171    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1172      if (Record.size() < 4) return Error("Invalid CMP record");
1173      const Type *OpTy = getTypeByID(Record[0]);
1174      Value *LHS = getFnValueByID(Record[1], OpTy);
1175      Value *RHS = getFnValueByID(Record[2], OpTy);
1176      if (OpTy == 0 || LHS == 0 || RHS == 0)
1177        return Error("Invalid CMP record");
1178      if (OpTy->isFPOrFPVector())
1179        I = new FCmpInst((FCmpInst::Predicate)Record[3], LHS, RHS);
1180      else
1181        I = new ICmpInst((ICmpInst::Predicate)Record[3], LHS, RHS);
1182      break;
1183    }
1184
1185    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1186      if (Record.size() == 0) {
1187        I = new ReturnInst();
1188        break;
1189      }
1190      if (Record.size() == 2) {
1191        const Type *OpTy = getTypeByID(Record[0]);
1192        Value *Op = getFnValueByID(Record[1], OpTy);
1193        if (!OpTy || !Op)
1194          return Error("Invalid RET record");
1195        I = new ReturnInst(Op);
1196        break;
1197      }
1198      return Error("Invalid RET record");
1199    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1200      if (Record.size() != 1 && Record.size() != 3)
1201        return Error("Invalid BR record");
1202      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1203      if (TrueDest == 0)
1204        return Error("Invalid BR record");
1205
1206      if (Record.size() == 1)
1207        I = new BranchInst(TrueDest);
1208      else {
1209        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1210        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1211        if (FalseDest == 0 || Cond == 0)
1212          return Error("Invalid BR record");
1213        I = new BranchInst(TrueDest, FalseDest, Cond);
1214      }
1215      break;
1216    }
1217    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1218      if (Record.size() < 3 || (Record.size() & 1) == 0)
1219        return Error("Invalid SWITCH record");
1220      const Type *OpTy = getTypeByID(Record[0]);
1221      Value *Cond = getFnValueByID(Record[1], OpTy);
1222      BasicBlock *Default = getBasicBlock(Record[2]);
1223      if (OpTy == 0 || Cond == 0 || Default == 0)
1224        return Error("Invalid SWITCH record");
1225      unsigned NumCases = (Record.size()-3)/2;
1226      SwitchInst *SI = new SwitchInst(Cond, Default, NumCases);
1227      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1228        ConstantInt *CaseVal =
1229          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1230        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1231        if (CaseVal == 0 || DestBB == 0) {
1232          delete SI;
1233          return Error("Invalid SWITCH record!");
1234        }
1235        SI->addCase(CaseVal, DestBB);
1236      }
1237      I = SI;
1238      break;
1239    }
1240
1241    case bitc::FUNC_CODE_INST_INVOKE: { // INVOKE: [cc,fnty, op0,op1,op2, ...]
1242      if (Record.size() < 5)
1243        return Error("Invalid INVOKE record");
1244      unsigned CCInfo = Record[0];
1245      const PointerType *CalleeTy =
1246        dyn_cast_or_null<PointerType>(getTypeByID(Record[1]));
1247      Value *Callee = getFnValueByID(Record[2], CalleeTy);
1248      BasicBlock *NormalBB = getBasicBlock(Record[3]);
1249      BasicBlock *UnwindBB = getBasicBlock(Record[4]);
1250      if (CalleeTy == 0 || Callee == 0 || NormalBB == 0 || UnwindBB == 0)
1251        return Error("Invalid INVOKE record");
1252
1253      const FunctionType *FTy =
1254        dyn_cast<FunctionType>(CalleeTy->getElementType());
1255
1256      // Check that the right number of fixed parameters are here.
1257      if (FTy == 0 || Record.size() < 5+FTy->getNumParams())
1258        return Error("Invalid INVOKE record");
1259
1260      SmallVector<Value*, 16> Ops;
1261      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1262        Ops.push_back(getFnValueByID(Record[5+i], FTy->getParamType(i)));
1263        if (Ops.back() == 0)
1264          return Error("Invalid INVOKE record");
1265      }
1266
1267      unsigned FirstVarargParam = 5+FTy->getNumParams();
1268      if (FTy->isVarArg()) {
1269        // Read type/value pairs for varargs params.
1270        if ((Record.size()-FirstVarargParam) & 1)
1271          return Error("Invalid INVOKE record");
1272
1273        for (unsigned i = FirstVarargParam, e = Record.size(); i != e; i += 2) {
1274          const Type *ArgTy = getTypeByID(Record[i]);
1275          Ops.push_back(getFnValueByID(Record[i+1], ArgTy));
1276          if (Ops.back() == 0 || ArgTy == 0)
1277            return Error("Invalid INVOKE record");
1278        }
1279      } else {
1280        if (Record.size() != FirstVarargParam)
1281          return Error("Invalid INVOKE record");
1282      }
1283
1284      I = new InvokeInst(Callee, NormalBB, UnwindBB, &Ops[0], Ops.size());
1285      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1286      break;
1287    }
1288    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1289      I = new UnwindInst();
1290      break;
1291    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1292      I = new UnreachableInst();
1293      break;
1294    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, #ops, val0,bb0, ...]
1295      if (Record.size() < 2 || Record.size() < 2+Record[1] || (Record[1]&1))
1296        return Error("Invalid PHI record");
1297      const Type *Ty = getTypeByID(Record[0]);
1298      if (!Ty) return Error("Invalid PHI record");
1299
1300      PHINode *PN = new PHINode(Ty);
1301      PN->reserveOperandSpace(Record[1]);
1302
1303      for (unsigned i = 0, e = Record[1]; i != e; i += 2) {
1304        Value *V = getFnValueByID(Record[2+i], Ty);
1305        BasicBlock *BB = getBasicBlock(Record[3+i]);
1306        if (!V || !BB) return Error("Invalid PHI record");
1307        PN->addIncoming(V, BB);
1308      }
1309      I = PN;
1310      break;
1311    }
1312
1313    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1314      if (Record.size() < 3)
1315        return Error("Invalid MALLOC record");
1316      const PointerType *Ty =
1317        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1318      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1319      unsigned Align = Record[2];
1320      if (!Ty || !Size) return Error("Invalid MALLOC record");
1321      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1322      break;
1323    }
1324    case bitc::FUNC_CODE_INST_FREE: { // FREE: [opty, op]
1325      if (Record.size() < 2)
1326        return Error("Invalid FREE record");
1327      const Type *OpTy = getTypeByID(Record[0]);
1328      Value *Op = getFnValueByID(Record[1], OpTy);
1329      if (!OpTy || !Op)
1330        return Error("Invalid FREE record");
1331      I = new FreeInst(Op);
1332      break;
1333    }
1334    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1335      if (Record.size() < 3)
1336        return Error("Invalid ALLOCA record");
1337      const PointerType *Ty =
1338        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1339      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1340      unsigned Align = Record[2];
1341      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1342      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1343      break;
1344    }
1345    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1346      if (Record.size() < 4)
1347        return Error("Invalid LOAD record");
1348      const Type *OpTy = getTypeByID(Record[0]);
1349      Value *Op = getFnValueByID(Record[1], OpTy);
1350      if (!OpTy || !Op)
1351        return Error("Invalid LOAD record");
1352      I = new LoadInst(Op, "", Record[3], (1 << Record[2]) >> 1);
1353      break;
1354    }
1355    case bitc::FUNC_CODE_INST_STORE: { // STORE:[ptrty,val,ptr, align, vol]
1356      if (Record.size() < 5)
1357        return Error("Invalid LOAD record");
1358      const PointerType *OpTy =
1359        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1360      Value *Op = getFnValueByID(Record[1], OpTy ? OpTy->getElementType() : 0);
1361      Value *Ptr = getFnValueByID(Record[2], OpTy);
1362      if (!OpTy || !Op || !Ptr)
1363        return Error("Invalid STORE record");
1364      I = new StoreInst(Op, Ptr, (1 << Record[3]) >> 1, Record[4]);
1365      break;
1366    }
1367    case bitc::FUNC_CODE_INST_CALL: { // CALL: [cc, fnty, fnid, arg0, arg1...]
1368      if (Record.size() < 3)
1369        return Error("Invalid CALL record");
1370      unsigned CCInfo = Record[0];
1371      const PointerType *OpTy =
1372        dyn_cast_or_null<PointerType>(getTypeByID(Record[1]));
1373      const FunctionType *FTy = 0;
1374      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1375      Value *Callee = getFnValueByID(Record[2], OpTy);
1376      if (!FTy || !Callee || Record.size() < FTy->getNumParams()+3)
1377        return Error("Invalid CALL record");
1378
1379      SmallVector<Value*, 16> Args;
1380      // Read the fixed params.
1381      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1382        Args.push_back(getFnValueByID(Record[i+3], FTy->getParamType(i)));
1383        if (Args.back() == 0) return Error("Invalid CALL record");
1384      }
1385
1386
1387      // Read type/value pairs for varargs params.
1388      unsigned NextArg = FTy->getNumParams()+3;
1389      if (!FTy->isVarArg()) {
1390        if (NextArg != Record.size())
1391          return Error("Invalid CALL record");
1392      } else {
1393        if ((Record.size()-NextArg) & 1)
1394          return Error("Invalid CALL record");
1395        for (unsigned e = Record.size(); NextArg != e; NextArg += 2) {
1396          Args.push_back(getFnValueByID(Record[NextArg+1],
1397                                        getTypeByID(Record[NextArg])));
1398          if (Args.back() == 0) return Error("Invalid CALL record");
1399        }
1400      }
1401
1402      I = new CallInst(Callee, &Args[0], Args.size());
1403      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1404      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1405      break;
1406    }
1407    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1408      if (Record.size() < 3)
1409        return Error("Invalid VAARG record");
1410      const Type *OpTy = getTypeByID(Record[0]);
1411      Value *Op = getFnValueByID(Record[1], OpTy);
1412      const Type *ResTy = getTypeByID(Record[2]);
1413      if (!OpTy || !Op || !ResTy)
1414        return Error("Invalid VAARG record");
1415      I = new VAArgInst(Op, ResTy);
1416      break;
1417    }
1418    }
1419
1420    // Add instruction to end of current BB.  If there is no current BB, reject
1421    // this file.
1422    if (CurBB == 0) {
1423      delete I;
1424      return Error("Invalid instruction with no BB");
1425    }
1426    CurBB->getInstList().push_back(I);
1427
1428    // If this was a terminator instruction, move to the next block.
1429    if (isa<TerminatorInst>(I)) {
1430      ++CurBBNo;
1431      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1432    }
1433
1434    // Non-void values get registered in the value table for future use.
1435    if (I && I->getType() != Type::VoidTy)
1436      ValueList.AssignValue(I, NextValueNo++);
1437  }
1438
1439  // Check the function list for unresolved values.
1440  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1441    if (A->getParent() == 0) {
1442      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1443      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1444        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1445          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1446          delete A;
1447        }
1448      }
1449    }
1450    return Error("Never resolved value found in function!");
1451  }
1452
1453  // Trim the value list down to the size it was before we parsed this function.
1454  ValueList.shrinkTo(ModuleValueListSize);
1455  std::vector<BasicBlock*>().swap(FunctionBBs);
1456
1457  return false;
1458}
1459
1460
1461//===----------------------------------------------------------------------===//
1462// External interface
1463//===----------------------------------------------------------------------===//
1464
1465/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1466///
1467ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1468                                               std::string *ErrMsg) {
1469  BitcodeReader *R = new BitcodeReader(Buffer);
1470  if (R->ParseBitcode()) {
1471    if (ErrMsg)
1472      *ErrMsg = R->getErrorString();
1473
1474    // Don't let the BitcodeReader dtor delete 'Buffer'.
1475    R->releaseMemoryBuffer();
1476    delete R;
1477    return 0;
1478  }
1479  return R;
1480}
1481
1482/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
1483/// If an error occurs, return null and fill in *ErrMsg if non-null.
1484Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
1485  BitcodeReader *R;
1486  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
1487  if (!R) return 0;
1488
1489  // Read the whole module, get a pointer to it, tell ModuleProvider not to
1490  // delete it when its dtor is run.
1491  Module *M = R->releaseModule(ErrMsg);
1492
1493  // Don't let the BitcodeReader dtor delete 'Buffer'.
1494  R->releaseMemoryBuffer();
1495  delete R;
1496  return M;
1497}
1498