BitcodeReader.cpp revision a9bb713130b073276a53a38fe0c37d314a3f1fc1 
1//===- BitcodeReader.cpp - Internal BitcodeReader implementation ----------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by Chris Lattner and is distributed under
6// the University of Illinois Open Source License.  See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This header defines the BitcodeReader class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Bitcode/ReaderWriter.h"
15#include "BitcodeReader.h"
16#include "llvm/Constants.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/InlineAsm.h"
19#include "llvm/Instructions.h"
20#include "llvm/Module.h"
21#include "llvm/ParameterAttributes.h"
22#include "llvm/ADT/SmallString.h"
23#include "llvm/Support/MathExtras.h"
24#include "llvm/Support/MemoryBuffer.h"
25using namespace llvm;
26
27BitcodeReader::~BitcodeReader() {
28  delete Buffer;
29}
30
31//===----------------------------------------------------------------------===//
32//  Helper functions to implement forward reference resolution, etc.
33//===----------------------------------------------------------------------===//
34
35/// ConvertToString - Convert a string from a record into an std::string, return
36/// true on failure.
37template<typename StrTy>
38static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
39                            StrTy &Result) {
40  if (Idx > Record.size())
41    return true;
42
43  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
44    Result += (char)Record[i];
45  return false;
46}
47
48static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
49  switch (Val) {
50  default: // Map unknown/new linkages to external
51  case 0: return GlobalValue::ExternalLinkage;
52  case 1: return GlobalValue::WeakLinkage;
53  case 2: return GlobalValue::AppendingLinkage;
54  case 3: return GlobalValue::InternalLinkage;
55  case 4: return GlobalValue::LinkOnceLinkage;
56  case 5: return GlobalValue::DLLImportLinkage;
57  case 6: return GlobalValue::DLLExportLinkage;
58  case 7: return GlobalValue::ExternalWeakLinkage;
59  }
60}
61
62static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
63  switch (Val) {
64  default: // Map unknown visibilities to default.
65  case 0: return GlobalValue::DefaultVisibility;
66  case 1: return GlobalValue::HiddenVisibility;
67  case 2: return GlobalValue::ProtectedVisibility;
68  }
69}
70
71static int GetDecodedCastOpcode(unsigned Val) {
72  switch (Val) {
73  default: return -1;
74  case bitc::CAST_TRUNC   : return Instruction::Trunc;
75  case bitc::CAST_ZEXT    : return Instruction::ZExt;
76  case bitc::CAST_SEXT    : return Instruction::SExt;
77  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
78  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
79  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
80  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
81  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
82  case bitc::CAST_FPEXT   : return Instruction::FPExt;
83  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
84  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
85  case bitc::CAST_BITCAST : return Instruction::BitCast;
86  }
87}
88static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
89  switch (Val) {
90  default: return -1;
91  case bitc::BINOP_ADD:  return Instruction::Add;
92  case bitc::BINOP_SUB:  return Instruction::Sub;
93  case bitc::BINOP_MUL:  return Instruction::Mul;
94  case bitc::BINOP_UDIV: return Instruction::UDiv;
95  case bitc::BINOP_SDIV:
96    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
97  case bitc::BINOP_UREM: return Instruction::URem;
98  case bitc::BINOP_SREM:
99    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
100  case bitc::BINOP_SHL:  return Instruction::Shl;
101  case bitc::BINOP_LSHR: return Instruction::LShr;
102  case bitc::BINOP_ASHR: return Instruction::AShr;
103  case bitc::BINOP_AND:  return Instruction::And;
104  case bitc::BINOP_OR:   return Instruction::Or;
105  case bitc::BINOP_XOR:  return Instruction::Xor;
106  }
107}
108
109
110namespace {
111  /// @brief A class for maintaining the slot number definition
112  /// as a placeholder for the actual definition for forward constants defs.
113  class ConstantPlaceHolder : public ConstantExpr {
114    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
115    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
116  public:
117    Use Op;
118    ConstantPlaceHolder(const Type *Ty)
119      : ConstantExpr(Ty, Instruction::UserOp1, &Op, 1),
120        Op(UndefValue::get(Type::Int32Ty), this) {
121    }
122  };
123}
124
125Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
126                                                    const Type *Ty) {
127  if (Idx >= size()) {
128    // Insert a bunch of null values.
129    Uses.resize(Idx+1);
130    OperandList = &Uses[0];
131    NumOperands = Idx+1;
132  }
133
134  if (Value *V = Uses[Idx]) {
135    assert(Ty == V->getType() && "Type mismatch in constant table!");
136    return cast<Constant>(V);
137  }
138
139  // Create and return a placeholder, which will later be RAUW'd.
140  Constant *C = new ConstantPlaceHolder(Ty);
141  Uses[Idx].init(C, this);
142  return C;
143}
144
145Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
146  if (Idx >= size()) {
147    // Insert a bunch of null values.
148    Uses.resize(Idx+1);
149    OperandList = &Uses[0];
150    NumOperands = Idx+1;
151  }
152
153  if (Value *V = Uses[Idx]) {
154    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
155    return V;
156  }
157
158  // No type specified, must be invalid reference.
159  if (Ty == 0) return 0;
160
161  // Create and return a placeholder, which will later be RAUW'd.
162  Value *V = new Argument(Ty);
163  Uses[Idx].init(V, this);
164  return V;
165}
166
167
168const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
169  // If the TypeID is in range, return it.
170  if (ID < TypeList.size())
171    return TypeList[ID].get();
172  if (!isTypeTable) return 0;
173
174  // The type table allows forward references.  Push as many Opaque types as
175  // needed to get up to ID.
176  while (TypeList.size() <= ID)
177    TypeList.push_back(OpaqueType::get());
178  return TypeList.back().get();
179}
180
181//===----------------------------------------------------------------------===//
182//  Functions for parsing blocks from the bitcode file
183//===----------------------------------------------------------------------===//
184
185bool BitcodeReader::ParseParamAttrBlock() {
186  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
187    return Error("Malformed block record");
188
189  if (!ParamAttrs.empty())
190    return Error("Multiple PARAMATTR blocks found!");
191
192  SmallVector<uint64_t, 64> Record;
193
194  ParamAttrsVector Attrs;
195
196  // Read all the records.
197  while (1) {
198    unsigned Code = Stream.ReadCode();
199    if (Code == bitc::END_BLOCK) {
200      if (Stream.ReadBlockEnd())
201        return Error("Error at end of PARAMATTR block");
202      return false;
203    }
204
205    if (Code == bitc::ENTER_SUBBLOCK) {
206      // No known subblocks, always skip them.
207      Stream.ReadSubBlockID();
208      if (Stream.SkipBlock())
209        return Error("Malformed block record");
210      continue;
211    }
212
213    if (Code == bitc::DEFINE_ABBREV) {
214      Stream.ReadAbbrevRecord();
215      continue;
216    }
217
218    // Read a record.
219    Record.clear();
220    switch (Stream.ReadRecord(Code, Record)) {
221    default:  // Default behavior: ignore.
222      break;
223    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
224      if (Record.size() & 1)
225        return Error("Invalid ENTRY record");
226
227      ParamAttrsWithIndex PAWI;
228      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
229        PAWI.index = Record[i];
230        PAWI.attrs = Record[i+1];
231        Attrs.push_back(PAWI);
232      }
233      ParamAttrs.push_back(ParamAttrsList::get(Attrs));
234      Attrs.clear();
235      break;
236    }
237    }
238  }
239}
240
241
242bool BitcodeReader::ParseTypeTable() {
243  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID))
244    return Error("Malformed block record");
245
246  if (!TypeList.empty())
247    return Error("Multiple TYPE_BLOCKs found!");
248
249  SmallVector<uint64_t, 64> Record;
250  unsigned NumRecords = 0;
251
252  // Read all the records for this type table.
253  while (1) {
254    unsigned Code = Stream.ReadCode();
255    if (Code == bitc::END_BLOCK) {
256      if (NumRecords != TypeList.size())
257        return Error("Invalid type forward reference in TYPE_BLOCK");
258      if (Stream.ReadBlockEnd())
259        return Error("Error at end of type table block");
260      return false;
261    }
262
263    if (Code == bitc::ENTER_SUBBLOCK) {
264      // No known subblocks, always skip them.
265      Stream.ReadSubBlockID();
266      if (Stream.SkipBlock())
267        return Error("Malformed block record");
268      continue;
269    }
270
271    if (Code == bitc::DEFINE_ABBREV) {
272      Stream.ReadAbbrevRecord();
273      continue;
274    }
275
276    // Read a record.
277    Record.clear();
278    const Type *ResultTy = 0;
279    switch (Stream.ReadRecord(Code, Record)) {
280    default:  // Default behavior: unknown type.
281      ResultTy = 0;
282      break;
283    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
284      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
285      // type list.  This allows us to reserve space.
286      if (Record.size() < 1)
287        return Error("Invalid TYPE_CODE_NUMENTRY record");
288      TypeList.reserve(Record[0]);
289      continue;
290    case bitc::TYPE_CODE_VOID:      // VOID
291      ResultTy = Type::VoidTy;
292      break;
293    case bitc::TYPE_CODE_FLOAT:     // FLOAT
294      ResultTy = Type::FloatTy;
295      break;
296    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
297      ResultTy = Type::DoubleTy;
298      break;
299    case bitc::TYPE_CODE_LABEL:     // LABEL
300      ResultTy = Type::LabelTy;
301      break;
302    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
303      ResultTy = 0;
304      break;
305    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
306      if (Record.size() < 1)
307        return Error("Invalid Integer type record");
308
309      ResultTy = IntegerType::get(Record[0]);
310      break;
311    case bitc::TYPE_CODE_POINTER:   // POINTER: [pointee type]
312      if (Record.size() < 1)
313        return Error("Invalid POINTER type record");
314      ResultTy = PointerType::get(getTypeByID(Record[0], true));
315      break;
316    case bitc::TYPE_CODE_FUNCTION: {
317      // FUNCTION: [vararg, attrid, retty, paramty x N]
318      if (Record.size() < 3)
319        return Error("Invalid FUNCTION type record");
320      std::vector<const Type*> ArgTys;
321      for (unsigned i = 3, e = Record.size(); i != e; ++i)
322        ArgTys.push_back(getTypeByID(Record[i], true));
323
324      ResultTy = FunctionType::get(getTypeByID(Record[2], true), ArgTys,
325                                   Record[0], getParamAttrs(Record[1]));
326      break;
327    }
328    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, eltty x N]
329      if (Record.size() < 1)
330        return Error("Invalid STRUCT type record");
331      std::vector<const Type*> EltTys;
332      for (unsigned i = 1, e = Record.size(); i != e; ++i)
333        EltTys.push_back(getTypeByID(Record[i], true));
334      ResultTy = StructType::get(EltTys, Record[0]);
335      break;
336    }
337    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
338      if (Record.size() < 2)
339        return Error("Invalid ARRAY type record");
340      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
341      break;
342    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
343      if (Record.size() < 2)
344        return Error("Invalid VECTOR type record");
345      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
346      break;
347    }
348
349    if (NumRecords == TypeList.size()) {
350      // If this is a new type slot, just append it.
351      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
352      ++NumRecords;
353    } else if (ResultTy == 0) {
354      // Otherwise, this was forward referenced, so an opaque type was created,
355      // but the result type is actually just an opaque.  Leave the one we
356      // created previously.
357      ++NumRecords;
358    } else {
359      // Otherwise, this was forward referenced, so an opaque type was created.
360      // Resolve the opaque type to the real type now.
361      assert(NumRecords < TypeList.size() && "Typelist imbalance");
362      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
363
364      // Don't directly push the new type on the Tab. Instead we want to replace
365      // the opaque type we previously inserted with the new concrete value. The
366      // refinement from the abstract (opaque) type to the new type causes all
367      // uses of the abstract type to use the concrete type (NewTy). This will
368      // also cause the opaque type to be deleted.
369      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
370
371      // This should have replaced the old opaque type with the new type in the
372      // value table... or with a preexisting type that was already in the
373      // system.  Let's just make sure it did.
374      assert(TypeList[NumRecords-1].get() != OldTy &&
375             "refineAbstractType didn't work!");
376    }
377  }
378}
379
380
381bool BitcodeReader::ParseTypeSymbolTable() {
382  if (Stream.EnterSubBlock(bitc::TYPE_SYMTAB_BLOCK_ID))
383    return Error("Malformed block record");
384
385  SmallVector<uint64_t, 64> Record;
386
387  // Read all the records for this type table.
388  std::string TypeName;
389  while (1) {
390    unsigned Code = Stream.ReadCode();
391    if (Code == bitc::END_BLOCK) {
392      if (Stream.ReadBlockEnd())
393        return Error("Error at end of type symbol table block");
394      return false;
395    }
396
397    if (Code == bitc::ENTER_SUBBLOCK) {
398      // No known subblocks, always skip them.
399      Stream.ReadSubBlockID();
400      if (Stream.SkipBlock())
401        return Error("Malformed block record");
402      continue;
403    }
404
405    if (Code == bitc::DEFINE_ABBREV) {
406      Stream.ReadAbbrevRecord();
407      continue;
408    }
409
410    // Read a record.
411    Record.clear();
412    switch (Stream.ReadRecord(Code, Record)) {
413    default:  // Default behavior: unknown type.
414      break;
415    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namechar x N]
416      if (ConvertToString(Record, 1, TypeName))
417        return Error("Invalid TST_ENTRY record");
418      unsigned TypeID = Record[0];
419      if (TypeID >= TypeList.size())
420        return Error("Invalid Type ID in TST_ENTRY record");
421
422      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
423      TypeName.clear();
424      break;
425    }
426  }
427}
428
429bool BitcodeReader::ParseValueSymbolTable() {
430  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
431    return Error("Malformed block record");
432
433  SmallVector<uint64_t, 64> Record;
434
435  // Read all the records for this value table.
436  SmallString<128> ValueName;
437  while (1) {
438    unsigned Code = Stream.ReadCode();
439    if (Code == bitc::END_BLOCK) {
440      if (Stream.ReadBlockEnd())
441        return Error("Error at end of value symbol table block");
442      return false;
443    }
444    if (Code == bitc::ENTER_SUBBLOCK) {
445      // No known subblocks, always skip them.
446      Stream.ReadSubBlockID();
447      if (Stream.SkipBlock())
448        return Error("Malformed block record");
449      continue;
450    }
451
452    if (Code == bitc::DEFINE_ABBREV) {
453      Stream.ReadAbbrevRecord();
454      continue;
455    }
456
457    // Read a record.
458    Record.clear();
459    switch (Stream.ReadRecord(Code, Record)) {
460    default:  // Default behavior: unknown type.
461      break;
462    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
463      if (ConvertToString(Record, 1, ValueName))
464        return Error("Invalid TST_ENTRY record");
465      unsigned ValueID = Record[0];
466      if (ValueID >= ValueList.size())
467        return Error("Invalid Value ID in VST_ENTRY record");
468      Value *V = ValueList[ValueID];
469
470      V->setName(&ValueName[0], ValueName.size());
471      ValueName.clear();
472      break;
473    }
474    case bitc::VST_CODE_BBENTRY: {
475      if (ConvertToString(Record, 1, ValueName))
476        return Error("Invalid VST_BBENTRY record");
477      BasicBlock *BB = getBasicBlock(Record[0]);
478      if (BB == 0)
479        return Error("Invalid BB ID in VST_BBENTRY record");
480
481      BB->setName(&ValueName[0], ValueName.size());
482      ValueName.clear();
483      break;
484    }
485    }
486  }
487}
488
489/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
490/// the LSB for dense VBR encoding.
491static uint64_t DecodeSignRotatedValue(uint64_t V) {
492  if ((V & 1) == 0)
493    return V >> 1;
494  if (V != 1)
495    return -(V >> 1);
496  // There is no such thing as -0 with integers.  "-0" really means MININT.
497  return 1ULL << 63;
498}
499
500/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
501/// values and aliases that we can.
502bool BitcodeReader::ResolveGlobalAndAliasInits() {
503  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
504  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
505
506  GlobalInitWorklist.swap(GlobalInits);
507  AliasInitWorklist.swap(AliasInits);
508
509  while (!GlobalInitWorklist.empty()) {
510    unsigned ValID = GlobalInitWorklist.back().second;
511    if (ValID >= ValueList.size()) {
512      // Not ready to resolve this yet, it requires something later in the file.
513      GlobalInits.push_back(GlobalInitWorklist.back());
514    } else {
515      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
516        GlobalInitWorklist.back().first->setInitializer(C);
517      else
518        return Error("Global variable initializer is not a constant!");
519    }
520    GlobalInitWorklist.pop_back();
521  }
522
523  while (!AliasInitWorklist.empty()) {
524    unsigned ValID = AliasInitWorklist.back().second;
525    if (ValID >= ValueList.size()) {
526      AliasInits.push_back(AliasInitWorklist.back());
527    } else {
528      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
529        AliasInitWorklist.back().first->setAliasee(C);
530      else
531        return Error("Alias initializer is not a constant!");
532    }
533    AliasInitWorklist.pop_back();
534  }
535  return false;
536}
537
538
539bool BitcodeReader::ParseConstants() {
540  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
541    return Error("Malformed block record");
542
543  SmallVector<uint64_t, 64> Record;
544
545  // Read all the records for this value table.
546  const Type *CurTy = Type::Int32Ty;
547  unsigned NextCstNo = ValueList.size();
548  while (1) {
549    unsigned Code = Stream.ReadCode();
550    if (Code == bitc::END_BLOCK) {
551      if (NextCstNo != ValueList.size())
552        return Error("Invalid constant reference!");
553
554      if (Stream.ReadBlockEnd())
555        return Error("Error at end of constants block");
556      return false;
557    }
558
559    if (Code == bitc::ENTER_SUBBLOCK) {
560      // No known subblocks, always skip them.
561      Stream.ReadSubBlockID();
562      if (Stream.SkipBlock())
563        return Error("Malformed block record");
564      continue;
565    }
566
567    if (Code == bitc::DEFINE_ABBREV) {
568      Stream.ReadAbbrevRecord();
569      continue;
570    }
571
572    // Read a record.
573    Record.clear();
574    Value *V = 0;
575    switch (Stream.ReadRecord(Code, Record)) {
576    default:  // Default behavior: unknown constant
577    case bitc::CST_CODE_UNDEF:     // UNDEF
578      V = UndefValue::get(CurTy);
579      break;
580    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
581      if (Record.empty())
582        return Error("Malformed CST_SETTYPE record");
583      if (Record[0] >= TypeList.size())
584        return Error("Invalid Type ID in CST_SETTYPE record");
585      CurTy = TypeList[Record[0]];
586      continue;  // Skip the ValueList manipulation.
587    case bitc::CST_CODE_NULL:      // NULL
588      V = Constant::getNullValue(CurTy);
589      break;
590    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
591      if (!isa<IntegerType>(CurTy) || Record.empty())
592        return Error("Invalid CST_INTEGER record");
593      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
594      break;
595    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
596      if (!isa<IntegerType>(CurTy) || Record.empty())
597        return Error("Invalid WIDE_INTEGER record");
598
599      unsigned NumWords = Record.size();
600      SmallVector<uint64_t, 8> Words;
601      Words.resize(NumWords);
602      for (unsigned i = 0; i != NumWords; ++i)
603        Words[i] = DecodeSignRotatedValue(Record[i]);
604      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
605                                 NumWords, &Words[0]));
606      break;
607    }
608    case bitc::CST_CODE_FLOAT:     // FLOAT: [fpval]
609      if (Record.empty())
610        return Error("Invalid FLOAT record");
611      if (CurTy == Type::FloatTy)
612        V = ConstantFP::get(CurTy, BitsToFloat(Record[0]));
613      else if (CurTy == Type::DoubleTy)
614        V = ConstantFP::get(CurTy, BitsToDouble(Record[0]));
615      else
616        V = UndefValue::get(CurTy);
617      break;
618
619    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
620      if (Record.empty())
621        return Error("Invalid CST_AGGREGATE record");
622
623      unsigned Size = Record.size();
624      std::vector<Constant*> Elts;
625
626      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
627        for (unsigned i = 0; i != Size; ++i)
628          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
629                                                     STy->getElementType(i)));
630        V = ConstantStruct::get(STy, Elts);
631      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
632        const Type *EltTy = ATy->getElementType();
633        for (unsigned i = 0; i != Size; ++i)
634          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
635        V = ConstantArray::get(ATy, Elts);
636      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
637        const Type *EltTy = VTy->getElementType();
638        for (unsigned i = 0; i != Size; ++i)
639          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
640        V = ConstantVector::get(Elts);
641      } else {
642        V = UndefValue::get(CurTy);
643      }
644      break;
645    }
646    case bitc::CST_CODE_STRING: { // STRING: [values]
647      if (Record.empty())
648        return Error("Invalid CST_AGGREGATE record");
649
650      const ArrayType *ATy = cast<ArrayType>(CurTy);
651      const Type *EltTy = ATy->getElementType();
652
653      unsigned Size = Record.size();
654      std::vector<Constant*> Elts;
655      for (unsigned i = 0; i != Size; ++i)
656        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
657      V = ConstantArray::get(ATy, Elts);
658      break;
659    }
660    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
661      if (Record.empty())
662        return Error("Invalid CST_AGGREGATE record");
663
664      const ArrayType *ATy = cast<ArrayType>(CurTy);
665      const Type *EltTy = ATy->getElementType();
666
667      unsigned Size = Record.size();
668      std::vector<Constant*> Elts;
669      for (unsigned i = 0; i != Size; ++i)
670        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
671      Elts.push_back(Constant::getNullValue(EltTy));
672      V = ConstantArray::get(ATy, Elts);
673      break;
674    }
675    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
676      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
677      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
678      if (Opc < 0) {
679        V = UndefValue::get(CurTy);  // Unknown binop.
680      } else {
681        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
682        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
683        V = ConstantExpr::get(Opc, LHS, RHS);
684      }
685      break;
686    }
687    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
688      if (Record.size() < 3) return Error("Invalid CE_CAST record");
689      int Opc = GetDecodedCastOpcode(Record[0]);
690      if (Opc < 0) {
691        V = UndefValue::get(CurTy);  // Unknown cast.
692      } else {
693        const Type *OpTy = getTypeByID(Record[1]);
694        if (!OpTy) return Error("Invalid CE_CAST record");
695        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
696        V = ConstantExpr::getCast(Opc, Op, CurTy);
697      }
698      break;
699    }
700    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
701      if (Record.size() & 1) return Error("Invalid CE_GEP record");
702      SmallVector<Constant*, 16> Elts;
703      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
704        const Type *ElTy = getTypeByID(Record[i]);
705        if (!ElTy) return Error("Invalid CE_GEP record");
706        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
707      }
708      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
709      break;
710    }
711    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
712      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
713      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
714                                                              Type::Int1Ty),
715                                  ValueList.getConstantFwdRef(Record[1],CurTy),
716                                  ValueList.getConstantFwdRef(Record[2],CurTy));
717      break;
718    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
719      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
720      const VectorType *OpTy =
721        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
722      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
723      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
724      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
725                                                  OpTy->getElementType());
726      V = ConstantExpr::getExtractElement(Op0, Op1);
727      break;
728    }
729    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
730      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
731      if (Record.size() < 3 || OpTy == 0)
732        return Error("Invalid CE_INSERTELT record");
733      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
734      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
735                                                  OpTy->getElementType());
736      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
737      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
738      break;
739    }
740    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
741      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
742      if (Record.size() < 3 || OpTy == 0)
743        return Error("Invalid CE_INSERTELT record");
744      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
745      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
746      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
747      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
748      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
749      break;
750    }
751    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
752      if (Record.size() < 4) return Error("Invalid CE_CMP record");
753      const Type *OpTy = getTypeByID(Record[0]);
754      if (OpTy == 0) return Error("Invalid CE_CMP record");
755      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
756      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
757
758      if (OpTy->isFloatingPoint())
759        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
760      else
761        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
762      break;
763    }
764    case bitc::CST_CODE_INLINEASM: {
765      if (Record.size() < 2) return Error("Invalid INLINEASM record");
766      std::string AsmStr, ConstrStr;
767      bool HasSideEffects = Record[0];
768      unsigned AsmStrSize = Record[1];
769      if (2+AsmStrSize >= Record.size())
770        return Error("Invalid INLINEASM record");
771      unsigned ConstStrSize = Record[2+AsmStrSize];
772      if (3+AsmStrSize+ConstStrSize > Record.size())
773        return Error("Invalid INLINEASM record");
774
775      for (unsigned i = 0; i != AsmStrSize; ++i)
776        AsmStr += (char)Record[2+i];
777      for (unsigned i = 0; i != ConstStrSize; ++i)
778        ConstrStr += (char)Record[3+AsmStrSize+i];
779      const PointerType *PTy = cast<PointerType>(CurTy);
780      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
781                         AsmStr, ConstrStr, HasSideEffects);
782      break;
783    }
784    }
785
786    ValueList.AssignValue(V, NextCstNo);
787    ++NextCstNo;
788  }
789}
790
791/// RememberAndSkipFunctionBody - When we see the block for a function body,
792/// remember where it is and then skip it.  This lets us lazily deserialize the
793/// functions.
794bool BitcodeReader::RememberAndSkipFunctionBody() {
795  // Get the function we are talking about.
796  if (FunctionsWithBodies.empty())
797    return Error("Insufficient function protos");
798
799  Function *Fn = FunctionsWithBodies.back();
800  FunctionsWithBodies.pop_back();
801
802  // Save the current stream state.
803  uint64_t CurBit = Stream.GetCurrentBitNo();
804  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
805
806  // Set the functions linkage to GhostLinkage so we know it is lazily
807  // deserialized.
808  Fn->setLinkage(GlobalValue::GhostLinkage);
809
810  // Skip over the function block for now.
811  if (Stream.SkipBlock())
812    return Error("Malformed block record");
813  return false;
814}
815
816bool BitcodeReader::ParseModule(const std::string &ModuleID) {
817  // Reject multiple MODULE_BLOCK's in a single bitstream.
818  if (TheModule)
819    return Error("Multiple MODULE_BLOCKs in same stream");
820
821  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
822    return Error("Malformed block record");
823
824  // Otherwise, create the module.
825  TheModule = new Module(ModuleID);
826
827  SmallVector<uint64_t, 64> Record;
828  std::vector<std::string> SectionTable;
829
830  // Read all the records for this module.
831  while (!Stream.AtEndOfStream()) {
832    unsigned Code = Stream.ReadCode();
833    if (Code == bitc::END_BLOCK) {
834      if (Stream.ReadBlockEnd())
835        return Error("Error at end of module block");
836
837      // Patch the initializers for globals and aliases up.
838      ResolveGlobalAndAliasInits();
839      if (!GlobalInits.empty() || !AliasInits.empty())
840        return Error("Malformed global initializer set");
841      if (!FunctionsWithBodies.empty())
842        return Error("Too few function bodies found");
843
844      // Force deallocation of memory for these vectors to favor the client that
845      // want lazy deserialization.
846      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
847      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
848      std::vector<Function*>().swap(FunctionsWithBodies);
849      return false;
850    }
851
852    if (Code == bitc::ENTER_SUBBLOCK) {
853      switch (Stream.ReadSubBlockID()) {
854      default:  // Skip unknown content.
855        if (Stream.SkipBlock())
856          return Error("Malformed block record");
857        break;
858      case bitc::BLOCKINFO_BLOCK_ID:
859        if (Stream.ReadBlockInfoBlock())
860          return Error("Malformed BlockInfoBlock");
861        break;
862      case bitc::PARAMATTR_BLOCK_ID:
863        if (ParseParamAttrBlock())
864          return true;
865        break;
866      case bitc::TYPE_BLOCK_ID:
867        if (ParseTypeTable())
868          return true;
869        break;
870      case bitc::TYPE_SYMTAB_BLOCK_ID:
871        if (ParseTypeSymbolTable())
872          return true;
873        break;
874      case bitc::VALUE_SYMTAB_BLOCK_ID:
875        if (ParseValueSymbolTable())
876          return true;
877        break;
878      case bitc::CONSTANTS_BLOCK_ID:
879        if (ParseConstants() || ResolveGlobalAndAliasInits())
880          return true;
881        break;
882      case bitc::FUNCTION_BLOCK_ID:
883        // If this is the first function body we've seen, reverse the
884        // FunctionsWithBodies list.
885        if (!HasReversedFunctionsWithBodies) {
886          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
887          HasReversedFunctionsWithBodies = true;
888        }
889
890        if (RememberAndSkipFunctionBody())
891          return true;
892        break;
893      }
894      continue;
895    }
896
897    if (Code == bitc::DEFINE_ABBREV) {
898      Stream.ReadAbbrevRecord();
899      continue;
900    }
901
902    // Read a record.
903    switch (Stream.ReadRecord(Code, Record)) {
904    default: break;  // Default behavior, ignore unknown content.
905    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
906      if (Record.size() < 1)
907        return Error("Malformed MODULE_CODE_VERSION");
908      // Only version #0 is supported so far.
909      if (Record[0] != 0)
910        return Error("Unknown bitstream version!");
911      break;
912    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
913      std::string S;
914      if (ConvertToString(Record, 0, S))
915        return Error("Invalid MODULE_CODE_TRIPLE record");
916      TheModule->setTargetTriple(S);
917      break;
918    }
919    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
920      std::string S;
921      if (ConvertToString(Record, 0, S))
922        return Error("Invalid MODULE_CODE_DATALAYOUT record");
923      TheModule->setDataLayout(S);
924      break;
925    }
926    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
927      std::string S;
928      if (ConvertToString(Record, 0, S))
929        return Error("Invalid MODULE_CODE_ASM record");
930      TheModule->setModuleInlineAsm(S);
931      break;
932    }
933    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
934      std::string S;
935      if (ConvertToString(Record, 0, S))
936        return Error("Invalid MODULE_CODE_DEPLIB record");
937      TheModule->addLibrary(S);
938      break;
939    }
940    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
941      std::string S;
942      if (ConvertToString(Record, 0, S))
943        return Error("Invalid MODULE_CODE_SECTIONNAME record");
944      SectionTable.push_back(S);
945      break;
946    }
947    // GLOBALVAR: [type, isconst, initid,
948    //             linkage, alignment, section, visibility, threadlocal]
949    case bitc::MODULE_CODE_GLOBALVAR: {
950      if (Record.size() < 6)
951        return Error("Invalid MODULE_CODE_GLOBALVAR record");
952      const Type *Ty = getTypeByID(Record[0]);
953      if (!isa<PointerType>(Ty))
954        return Error("Global not a pointer type!");
955      Ty = cast<PointerType>(Ty)->getElementType();
956
957      bool isConstant = Record[1];
958      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
959      unsigned Alignment = (1 << Record[4]) >> 1;
960      std::string Section;
961      if (Record[5]) {
962        if (Record[5]-1 >= SectionTable.size())
963          return Error("Invalid section ID");
964        Section = SectionTable[Record[5]-1];
965      }
966      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
967      if (Record.size() > 6)
968        Visibility = GetDecodedVisibility(Record[6]);
969      bool isThreadLocal = false;
970      if (Record.size() > 7)
971        isThreadLocal = Record[7];
972
973      GlobalVariable *NewGV =
974        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule);
975      NewGV->setAlignment(Alignment);
976      if (!Section.empty())
977        NewGV->setSection(Section);
978      NewGV->setVisibility(Visibility);
979      NewGV->setThreadLocal(isThreadLocal);
980
981      ValueList.push_back(NewGV);
982
983      // Remember which value to use for the global initializer.
984      if (unsigned InitID = Record[2])
985        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
986      break;
987    }
988    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
989    //             alignment, section, visibility]
990    case bitc::MODULE_CODE_FUNCTION: {
991      if (Record.size() < 8)
992        return Error("Invalid MODULE_CODE_FUNCTION record");
993      const Type *Ty = getTypeByID(Record[0]);
994      if (!isa<PointerType>(Ty))
995        return Error("Function not a pointer type!");
996      const FunctionType *FTy =
997        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
998      if (!FTy)
999        return Error("Function not a pointer to function type!");
1000
1001      Function *Func = new Function(FTy, GlobalValue::ExternalLinkage,
1002                                    "", TheModule);
1003
1004      Func->setCallingConv(Record[1]);
1005      bool isProto = Record[2];
1006      Func->setLinkage(GetDecodedLinkage(Record[3]));
1007
1008      assert(Func->getFunctionType()->getParamAttrs() ==
1009             getParamAttrs(Record[4]));
1010
1011      Func->setAlignment((1 << Record[5]) >> 1);
1012      if (Record[6]) {
1013        if (Record[6]-1 >= SectionTable.size())
1014          return Error("Invalid section ID");
1015        Func->setSection(SectionTable[Record[6]-1]);
1016      }
1017      Func->setVisibility(GetDecodedVisibility(Record[7]));
1018
1019      ValueList.push_back(Func);
1020
1021      // If this is a function with a body, remember the prototype we are
1022      // creating now, so that we can match up the body with them later.
1023      if (!isProto)
1024        FunctionsWithBodies.push_back(Func);
1025      break;
1026    }
1027    // ALIAS: [alias type, aliasee val#, linkage]
1028    case bitc::MODULE_CODE_ALIAS: {
1029      if (Record.size() < 3)
1030        return Error("Invalid MODULE_ALIAS record");
1031      const Type *Ty = getTypeByID(Record[0]);
1032      if (!isa<PointerType>(Ty))
1033        return Error("Function not a pointer type!");
1034
1035      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1036                                           "", 0, TheModule);
1037      ValueList.push_back(NewGA);
1038      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1039      break;
1040    }
1041    /// MODULE_CODE_PURGEVALS: [numvals]
1042    case bitc::MODULE_CODE_PURGEVALS:
1043      // Trim down the value list to the specified size.
1044      if (Record.size() < 1 || Record[0] > ValueList.size())
1045        return Error("Invalid MODULE_PURGEVALS record");
1046      ValueList.shrinkTo(Record[0]);
1047      break;
1048    }
1049    Record.clear();
1050  }
1051
1052  return Error("Premature end of bitstream");
1053}
1054
1055
1056bool BitcodeReader::ParseBitcode() {
1057  TheModule = 0;
1058
1059  if (Buffer->getBufferSize() & 3)
1060    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1061
1062  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1063  Stream.init(BufPtr, BufPtr+Buffer->getBufferSize());
1064
1065  // Sniff for the signature.
1066  if (Stream.Read(8) != 'B' ||
1067      Stream.Read(8) != 'C' ||
1068      Stream.Read(4) != 0x0 ||
1069      Stream.Read(4) != 0xC ||
1070      Stream.Read(4) != 0xE ||
1071      Stream.Read(4) != 0xD)
1072    return Error("Invalid bitcode signature");
1073
1074  // We expect a number of well-defined blocks, though we don't necessarily
1075  // need to understand them all.
1076  while (!Stream.AtEndOfStream()) {
1077    unsigned Code = Stream.ReadCode();
1078
1079    if (Code != bitc::ENTER_SUBBLOCK)
1080      return Error("Invalid record at top-level");
1081
1082    unsigned BlockID = Stream.ReadSubBlockID();
1083
1084    // We only know the MODULE subblock ID.
1085    switch (BlockID) {
1086    case bitc::BLOCKINFO_BLOCK_ID:
1087      if (Stream.ReadBlockInfoBlock())
1088        return Error("Malformed BlockInfoBlock");
1089      break;
1090    case bitc::MODULE_BLOCK_ID:
1091      if (ParseModule(Buffer->getBufferIdentifier()))
1092        return true;
1093      break;
1094    default:
1095      if (Stream.SkipBlock())
1096        return Error("Malformed block record");
1097      break;
1098    }
1099  }
1100
1101  return false;
1102}
1103
1104
1105bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1106  // If it already is material, ignore the request.
1107  if (!F->hasNotBeenReadFromBytecode()) return false;
1108
1109  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1110    DeferredFunctionInfo.find(F);
1111  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1112
1113  // Move the bit stream to the saved position of the deferred function body and
1114  // restore the real linkage type for the function.
1115  Stream.JumpToBit(DFII->second.first);
1116  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1117  DeferredFunctionInfo.erase(DFII);
1118
1119  if (ParseFunctionBody(F)) {
1120    if (ErrInfo) *ErrInfo = ErrorString;
1121    return true;
1122  }
1123
1124  return false;
1125}
1126
1127Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
1128  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1129    DeferredFunctionInfo.begin();
1130  while (!DeferredFunctionInfo.empty()) {
1131    Function *F = (*I++).first;
1132    assert(F->hasNotBeenReadFromBytecode() &&
1133           "Deserialized function found in map!");
1134    if (materializeFunction(F, ErrInfo))
1135      return 0;
1136  }
1137  return TheModule;
1138}
1139
1140
1141/// ParseFunctionBody - Lazily parse the specified function body block.
1142bool BitcodeReader::ParseFunctionBody(Function *F) {
1143  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1144    return Error("Malformed block record");
1145
1146  unsigned ModuleValueListSize = ValueList.size();
1147
1148  // Add all the function arguments to the value table.
1149  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1150    ValueList.push_back(I);
1151
1152  unsigned NextValueNo = ValueList.size();
1153  BasicBlock *CurBB = 0;
1154  unsigned CurBBNo = 0;
1155
1156  // Read all the records.
1157  SmallVector<uint64_t, 64> Record;
1158  while (1) {
1159    unsigned Code = Stream.ReadCode();
1160    if (Code == bitc::END_BLOCK) {
1161      if (Stream.ReadBlockEnd())
1162        return Error("Error at end of function block");
1163      break;
1164    }
1165
1166    if (Code == bitc::ENTER_SUBBLOCK) {
1167      switch (Stream.ReadSubBlockID()) {
1168      default:  // Skip unknown content.
1169        if (Stream.SkipBlock())
1170          return Error("Malformed block record");
1171        break;
1172      case bitc::CONSTANTS_BLOCK_ID:
1173        if (ParseConstants()) return true;
1174        NextValueNo = ValueList.size();
1175        break;
1176      case bitc::VALUE_SYMTAB_BLOCK_ID:
1177        if (ParseValueSymbolTable()) return true;
1178        break;
1179      }
1180      continue;
1181    }
1182
1183    if (Code == bitc::DEFINE_ABBREV) {
1184      Stream.ReadAbbrevRecord();
1185      continue;
1186    }
1187
1188    // Read a record.
1189    Record.clear();
1190    Instruction *I = 0;
1191    switch (Stream.ReadRecord(Code, Record)) {
1192    default: // Default behavior: reject
1193      return Error("Unknown instruction");
1194    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1195      if (Record.size() < 1 || Record[0] == 0)
1196        return Error("Invalid DECLAREBLOCKS record");
1197      // Create all the basic blocks for the function.
1198      FunctionBBs.resize(Record[0]);
1199      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1200        FunctionBBs[i] = new BasicBlock("", F);
1201      CurBB = FunctionBBs[0];
1202      continue;
1203
1204    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1205      unsigned OpNum = 0;
1206      Value *LHS, *RHS;
1207      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1208          getValue(Record, OpNum, LHS->getType(), RHS) ||
1209          OpNum+1 != Record.size())
1210        return Error("Invalid BINOP record");
1211
1212      int Opc = GetDecodedBinaryOpcode(Record[OpNum], LHS->getType());
1213      if (Opc == -1) return Error("Invalid BINOP record");
1214      I = BinaryOperator::create((Instruction::BinaryOps)Opc, LHS, RHS);
1215      break;
1216    }
1217    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
1218      unsigned OpNum = 0;
1219      Value *Op;
1220      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1221          OpNum+2 != Record.size())
1222        return Error("Invalid CAST record");
1223
1224      const Type *ResTy = getTypeByID(Record[OpNum]);
1225      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
1226      if (Opc == -1 || ResTy == 0)
1227        return Error("Invalid CAST record");
1228      I = CastInst::create((Instruction::CastOps)Opc, Op, ResTy);
1229      break;
1230    }
1231    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
1232      unsigned OpNum = 0;
1233      Value *BasePtr;
1234      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
1235        return Error("Invalid GEP record");
1236
1237      SmallVector<Value*, 16> GEPIdx;
1238      while (OpNum != Record.size()) {
1239        Value *Op;
1240        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1241          return Error("Invalid GEP record");
1242        GEPIdx.push_back(Op);
1243      }
1244
1245      I = new GetElementPtrInst(BasePtr, &GEPIdx[0], GEPIdx.size());
1246      break;
1247    }
1248
1249    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
1250      unsigned OpNum = 0;
1251      Value *TrueVal, *FalseVal, *Cond;
1252      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
1253          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
1254          getValue(Record, OpNum, Type::Int1Ty, Cond))
1255        return Error("Invalid SELECT record");
1256
1257      I = new SelectInst(Cond, TrueVal, FalseVal);
1258      break;
1259    }
1260
1261    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1262      unsigned OpNum = 0;
1263      Value *Vec, *Idx;
1264      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1265          getValue(Record, OpNum, Type::Int32Ty, Idx))
1266        return Error("Invalid EXTRACTELT record");
1267      I = new ExtractElementInst(Vec, Idx);
1268      break;
1269    }
1270
1271    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1272      unsigned OpNum = 0;
1273      Value *Vec, *Elt, *Idx;
1274      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1275          getValue(Record, OpNum,
1276                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
1277          getValue(Record, OpNum, Type::Int32Ty, Idx))
1278        return Error("Invalid INSERTELT record");
1279      I = new InsertElementInst(Vec, Elt, Idx);
1280      break;
1281    }
1282
1283    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
1284      unsigned OpNum = 0;
1285      Value *Vec1, *Vec2, *Mask;
1286      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
1287          getValue(Record, OpNum, Vec1->getType(), Vec2))
1288        return Error("Invalid SHUFFLEVEC record");
1289
1290      const Type *MaskTy =
1291        VectorType::get(Type::Int32Ty,
1292                        cast<VectorType>(Vec1->getType())->getNumElements());
1293
1294      if (getValue(Record, OpNum, MaskTy, Mask))
1295        return Error("Invalid SHUFFLEVEC record");
1296      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1297      break;
1298    }
1299
1300    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1301      unsigned OpNum = 0;
1302      Value *LHS, *RHS;
1303      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1304          getValue(Record, OpNum, LHS->getType(), RHS) ||
1305          OpNum+1 != Record.size())
1306        return Error("Invalid CMP record");
1307
1308      if (LHS->getType()->isFPOrFPVector())
1309        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1310      else
1311        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1312      break;
1313    }
1314
1315    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1316      if (Record.size() == 0) {
1317        I = new ReturnInst();
1318        break;
1319      } else {
1320        unsigned OpNum = 0;
1321        Value *Op;
1322        if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1323            OpNum != Record.size())
1324          return Error("Invalid RET record");
1325        I = new ReturnInst(Op);
1326        break;
1327      }
1328    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1329      if (Record.size() != 1 && Record.size() != 3)
1330        return Error("Invalid BR record");
1331      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1332      if (TrueDest == 0)
1333        return Error("Invalid BR record");
1334
1335      if (Record.size() == 1)
1336        I = new BranchInst(TrueDest);
1337      else {
1338        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1339        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1340        if (FalseDest == 0 || Cond == 0)
1341          return Error("Invalid BR record");
1342        I = new BranchInst(TrueDest, FalseDest, Cond);
1343      }
1344      break;
1345    }
1346    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1347      if (Record.size() < 3 || (Record.size() & 1) == 0)
1348        return Error("Invalid SWITCH record");
1349      const Type *OpTy = getTypeByID(Record[0]);
1350      Value *Cond = getFnValueByID(Record[1], OpTy);
1351      BasicBlock *Default = getBasicBlock(Record[2]);
1352      if (OpTy == 0 || Cond == 0 || Default == 0)
1353        return Error("Invalid SWITCH record");
1354      unsigned NumCases = (Record.size()-3)/2;
1355      SwitchInst *SI = new SwitchInst(Cond, Default, NumCases);
1356      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1357        ConstantInt *CaseVal =
1358          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1359        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1360        if (CaseVal == 0 || DestBB == 0) {
1361          delete SI;
1362          return Error("Invalid SWITCH record!");
1363        }
1364        SI->addCase(CaseVal, DestBB);
1365      }
1366      I = SI;
1367      break;
1368    }
1369
1370    case bitc::FUNC_CODE_INST_INVOKE: { // INVOKE: [cc,fnty, op0,op1,op2, ...]
1371      if (Record.size() < 4) return Error("Invalid INVOKE record");
1372      unsigned CCInfo = Record[1];
1373      BasicBlock *NormalBB = getBasicBlock(Record[2]);
1374      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
1375
1376      unsigned OpNum = 4;
1377      Value *Callee;
1378      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1379        return Error("Invalid INVOKE record");
1380
1381      const PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
1382      const FunctionType *FTy = !CalleeTy ? 0 :
1383        dyn_cast<FunctionType>(CalleeTy->getElementType());
1384
1385      // Check that the right number of fixed parameters are here.
1386      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
1387          Record.size() < OpNum+FTy->getNumParams())
1388        return Error("Invalid INVOKE record");
1389
1390      assert(FTy->getParamAttrs() == getParamAttrs(Record[0]));
1391
1392      SmallVector<Value*, 16> Ops;
1393      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1394        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1395        if (Ops.back() == 0) return Error("Invalid INVOKE record");
1396      }
1397
1398      if (!FTy->isVarArg()) {
1399        if (Record.size() != OpNum)
1400          return Error("Invalid INVOKE record");
1401      } else {
1402        // Read type/value pairs for varargs params.
1403        while (OpNum != Record.size()) {
1404          Value *Op;
1405          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1406            return Error("Invalid INVOKE record");
1407          Ops.push_back(Op);
1408        }
1409      }
1410
1411      I = new InvokeInst(Callee, NormalBB, UnwindBB, &Ops[0], Ops.size());
1412      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1413      break;
1414    }
1415    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1416      I = new UnwindInst();
1417      break;
1418    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1419      I = new UnreachableInst();
1420      break;
1421    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
1422      if (Record.size() < 1 || ((Record.size()-1)&1))
1423        return Error("Invalid PHI record");
1424      const Type *Ty = getTypeByID(Record[0]);
1425      if (!Ty) return Error("Invalid PHI record");
1426
1427      PHINode *PN = new PHINode(Ty);
1428      PN->reserveOperandSpace(Record.size()-1);
1429
1430      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
1431        Value *V = getFnValueByID(Record[1+i], Ty);
1432        BasicBlock *BB = getBasicBlock(Record[2+i]);
1433        if (!V || !BB) return Error("Invalid PHI record");
1434        PN->addIncoming(V, BB);
1435      }
1436      I = PN;
1437      break;
1438    }
1439
1440    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1441      if (Record.size() < 3)
1442        return Error("Invalid MALLOC record");
1443      const PointerType *Ty =
1444        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1445      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1446      unsigned Align = Record[2];
1447      if (!Ty || !Size) return Error("Invalid MALLOC record");
1448      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1449      break;
1450    }
1451    case bitc::FUNC_CODE_INST_FREE: { // FREE: [op, opty]
1452      unsigned OpNum = 0;
1453      Value *Op;
1454      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1455          OpNum != Record.size())
1456        return Error("Invalid FREE record");
1457      I = new FreeInst(Op);
1458      break;
1459    }
1460    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1461      if (Record.size() < 3)
1462        return Error("Invalid ALLOCA record");
1463      const PointerType *Ty =
1464        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1465      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1466      unsigned Align = Record[2];
1467      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1468      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1469      break;
1470    }
1471    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1472      unsigned OpNum = 0;
1473      Value *Op;
1474      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1475          OpNum+2 != Record.size())
1476        return Error("Invalid LOAD record");
1477
1478      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1479      break;
1480    }
1481    case bitc::FUNC_CODE_INST_STORE: { // STORE:[val, valty, ptr, align, vol]
1482      unsigned OpNum = 0;
1483      Value *Val, *Ptr;
1484      if (getValueTypePair(Record, OpNum, NextValueNo, Val) ||
1485          getValue(Record, OpNum, PointerType::get(Val->getType()), Ptr) ||
1486          OpNum+2 != Record.size())
1487        return Error("Invalid STORE record");
1488
1489      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1490      break;
1491    }
1492    case bitc::FUNC_CODE_INST_CALL: { // CALL: [cc, fnty, fnid, arg0, arg1...]
1493      if (Record.size() < 2)
1494        return Error("Invalid CALL record");
1495
1496      unsigned CCInfo = Record[1];
1497
1498      unsigned OpNum = 2;
1499      Value *Callee;
1500      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1501        return Error("Invalid CALL record");
1502
1503      const PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
1504      const FunctionType *FTy = 0;
1505      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1506      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
1507        return Error("Invalid CALL record");
1508
1509      assert(FTy->getParamAttrs() == getParamAttrs(Record[0]));
1510
1511      SmallVector<Value*, 16> Args;
1512      // Read the fixed params.
1513      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1514        Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1515        if (Args.back() == 0) return Error("Invalid CALL record");
1516      }
1517
1518      // Read type/value pairs for varargs params.
1519      if (!FTy->isVarArg()) {
1520        if (OpNum != Record.size())
1521          return Error("Invalid CALL record");
1522      } else {
1523        while (OpNum != Record.size()) {
1524          Value *Op;
1525          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1526            return Error("Invalid CALL record");
1527          Args.push_back(Op);
1528        }
1529      }
1530
1531      I = new CallInst(Callee, &Args[0], Args.size());
1532      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1533      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1534      break;
1535    }
1536    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1537      if (Record.size() < 3)
1538        return Error("Invalid VAARG record");
1539      const Type *OpTy = getTypeByID(Record[0]);
1540      Value *Op = getFnValueByID(Record[1], OpTy);
1541      const Type *ResTy = getTypeByID(Record[2]);
1542      if (!OpTy || !Op || !ResTy)
1543        return Error("Invalid VAARG record");
1544      I = new VAArgInst(Op, ResTy);
1545      break;
1546    }
1547    }
1548
1549    // Add instruction to end of current BB.  If there is no current BB, reject
1550    // this file.
1551    if (CurBB == 0) {
1552      delete I;
1553      return Error("Invalid instruction with no BB");
1554    }
1555    CurBB->getInstList().push_back(I);
1556
1557    // If this was a terminator instruction, move to the next block.
1558    if (isa<TerminatorInst>(I)) {
1559      ++CurBBNo;
1560      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1561    }
1562
1563    // Non-void values get registered in the value table for future use.
1564    if (I && I->getType() != Type::VoidTy)
1565      ValueList.AssignValue(I, NextValueNo++);
1566  }
1567
1568  // Check the function list for unresolved values.
1569  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1570    if (A->getParent() == 0) {
1571      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1572      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1573        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1574          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1575          delete A;
1576        }
1577      }
1578      return Error("Never resolved value found in function!");
1579    }
1580  }
1581
1582  // Trim the value list down to the size it was before we parsed this function.
1583  ValueList.shrinkTo(ModuleValueListSize);
1584  std::vector<BasicBlock*>().swap(FunctionBBs);
1585
1586  return false;
1587}
1588
1589
1590//===----------------------------------------------------------------------===//
1591// External interface
1592//===----------------------------------------------------------------------===//
1593
1594/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1595///
1596ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1597                                               std::string *ErrMsg) {
1598  BitcodeReader *R = new BitcodeReader(Buffer);
1599  if (R->ParseBitcode()) {
1600    if (ErrMsg)
1601      *ErrMsg = R->getErrorString();
1602
1603    // Don't let the BitcodeReader dtor delete 'Buffer'.
1604    R->releaseMemoryBuffer();
1605    delete R;
1606    return 0;
1607  }
1608  return R;
1609}
1610
1611/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
1612/// If an error occurs, return null and fill in *ErrMsg if non-null.
1613Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
1614  BitcodeReader *R;
1615  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
1616  if (!R) return 0;
1617
1618  // Read the whole module, get a pointer to it, tell ModuleProvider not to
1619  // delete it when its dtor is run.
1620  Module *M = R->releaseModule(ErrMsg);
1621
1622  // Don't let the BitcodeReader dtor delete 'Buffer'.
1623  R->releaseMemoryBuffer();
1624  delete R;
1625  return M;
1626}
1627