BitcodeReader.cpp revision b348bb81253a1105d23ab1a1771f8d2a6546aa1b 
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
27void BitcodeReader::FreeState() {
28  delete Buffer;
29  Buffer = 0;
30  std::vector<PATypeHolder>().swap(TypeList);
31  ValueList.clear();
32  std::vector<const ParamAttrsList*>().swap(ParamAttrs);
33  std::vector<BasicBlock*>().swap(FunctionBBs);
34  std::vector<Function*>().swap(FunctionsWithBodies);
35  DeferredFunctionInfo.clear();
36}
37
38//===----------------------------------------------------------------------===//
39//  Helper functions to implement forward reference resolution, etc.
40//===----------------------------------------------------------------------===//
41
42/// ConvertToString - Convert a string from a record into an std::string, return
43/// true on failure.
44template<typename StrTy>
45static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
46                            StrTy &Result) {
47  if (Idx > Record.size())
48    return true;
49
50  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
51    Result += (char)Record[i];
52  return false;
53}
54
55static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
56  switch (Val) {
57  default: // Map unknown/new linkages to external
58  case 0: return GlobalValue::ExternalLinkage;
59  case 1: return GlobalValue::WeakLinkage;
60  case 2: return GlobalValue::AppendingLinkage;
61  case 3: return GlobalValue::InternalLinkage;
62  case 4: return GlobalValue::LinkOnceLinkage;
63  case 5: return GlobalValue::DLLImportLinkage;
64  case 6: return GlobalValue::DLLExportLinkage;
65  case 7: return GlobalValue::ExternalWeakLinkage;
66  }
67}
68
69static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
70  switch (Val) {
71  default: // Map unknown visibilities to default.
72  case 0: return GlobalValue::DefaultVisibility;
73  case 1: return GlobalValue::HiddenVisibility;
74  case 2: return GlobalValue::ProtectedVisibility;
75  }
76}
77
78static int GetDecodedCastOpcode(unsigned Val) {
79  switch (Val) {
80  default: return -1;
81  case bitc::CAST_TRUNC   : return Instruction::Trunc;
82  case bitc::CAST_ZEXT    : return Instruction::ZExt;
83  case bitc::CAST_SEXT    : return Instruction::SExt;
84  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
85  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
86  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
87  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
88  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
89  case bitc::CAST_FPEXT   : return Instruction::FPExt;
90  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
91  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
92  case bitc::CAST_BITCAST : return Instruction::BitCast;
93  }
94}
95static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
96  switch (Val) {
97  default: return -1;
98  case bitc::BINOP_ADD:  return Instruction::Add;
99  case bitc::BINOP_SUB:  return Instruction::Sub;
100  case bitc::BINOP_MUL:  return Instruction::Mul;
101  case bitc::BINOP_UDIV: return Instruction::UDiv;
102  case bitc::BINOP_SDIV:
103    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
104  case bitc::BINOP_UREM: return Instruction::URem;
105  case bitc::BINOP_SREM:
106    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
107  case bitc::BINOP_SHL:  return Instruction::Shl;
108  case bitc::BINOP_LSHR: return Instruction::LShr;
109  case bitc::BINOP_ASHR: return Instruction::AShr;
110  case bitc::BINOP_AND:  return Instruction::And;
111  case bitc::BINOP_OR:   return Instruction::Or;
112  case bitc::BINOP_XOR:  return Instruction::Xor;
113  }
114}
115
116
117namespace {
118  /// @brief A class for maintaining the slot number definition
119  /// as a placeholder for the actual definition for forward constants defs.
120  class ConstantPlaceHolder : public ConstantExpr {
121    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
122    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
123  public:
124    Use Op;
125    ConstantPlaceHolder(const Type *Ty)
126      : ConstantExpr(Ty, Instruction::UserOp1, &Op, 1),
127        Op(UndefValue::get(Type::Int32Ty), this) {
128    }
129  };
130}
131
132Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
133                                                    const Type *Ty) {
134  if (Idx >= size()) {
135    // Insert a bunch of null values.
136    Uses.resize(Idx+1);
137    OperandList = &Uses[0];
138    NumOperands = Idx+1;
139  }
140
141  if (Value *V = Uses[Idx]) {
142    assert(Ty == V->getType() && "Type mismatch in constant table!");
143    return cast<Constant>(V);
144  }
145
146  // Create and return a placeholder, which will later be RAUW'd.
147  Constant *C = new ConstantPlaceHolder(Ty);
148  Uses[Idx].init(C, this);
149  return C;
150}
151
152Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
153  if (Idx >= size()) {
154    // Insert a bunch of null values.
155    Uses.resize(Idx+1);
156    OperandList = &Uses[0];
157    NumOperands = Idx+1;
158  }
159
160  if (Value *V = Uses[Idx]) {
161    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
162    return V;
163  }
164
165  // No type specified, must be invalid reference.
166  if (Ty == 0) return 0;
167
168  // Create and return a placeholder, which will later be RAUW'd.
169  Value *V = new Argument(Ty);
170  Uses[Idx].init(V, this);
171  return V;
172}
173
174
175const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
176  // If the TypeID is in range, return it.
177  if (ID < TypeList.size())
178    return TypeList[ID].get();
179  if (!isTypeTable) return 0;
180
181  // The type table allows forward references.  Push as many Opaque types as
182  // needed to get up to ID.
183  while (TypeList.size() <= ID)
184    TypeList.push_back(OpaqueType::get());
185  return TypeList.back().get();
186}
187
188//===----------------------------------------------------------------------===//
189//  Functions for parsing blocks from the bitcode file
190//===----------------------------------------------------------------------===//
191
192bool BitcodeReader::ParseParamAttrBlock() {
193  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
194    return Error("Malformed block record");
195
196  if (!ParamAttrs.empty())
197    return Error("Multiple PARAMATTR blocks found!");
198
199  SmallVector<uint64_t, 64> Record;
200
201  ParamAttrsVector Attrs;
202
203  // Read all the records.
204  while (1) {
205    unsigned Code = Stream.ReadCode();
206    if (Code == bitc::END_BLOCK) {
207      if (Stream.ReadBlockEnd())
208        return Error("Error at end of PARAMATTR block");
209      return false;
210    }
211
212    if (Code == bitc::ENTER_SUBBLOCK) {
213      // No known subblocks, always skip them.
214      Stream.ReadSubBlockID();
215      if (Stream.SkipBlock())
216        return Error("Malformed block record");
217      continue;
218    }
219
220    if (Code == bitc::DEFINE_ABBREV) {
221      Stream.ReadAbbrevRecord();
222      continue;
223    }
224
225    // Read a record.
226    Record.clear();
227    switch (Stream.ReadRecord(Code, Record)) {
228    default:  // Default behavior: ignore.
229      break;
230    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
231      if (Record.size() & 1)
232        return Error("Invalid ENTRY record");
233
234      ParamAttrsWithIndex PAWI;
235      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
236        PAWI.index = Record[i];
237        PAWI.attrs = Record[i+1];
238        Attrs.push_back(PAWI);
239      }
240      ParamAttrs.push_back(ParamAttrsList::get(Attrs));
241      Attrs.clear();
242      break;
243    }
244    }
245  }
246}
247
248
249bool BitcodeReader::ParseTypeTable() {
250  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID))
251    return Error("Malformed block record");
252
253  if (!TypeList.empty())
254    return Error("Multiple TYPE_BLOCKs found!");
255
256  SmallVector<uint64_t, 64> Record;
257  unsigned NumRecords = 0;
258
259  // Read all the records for this type table.
260  while (1) {
261    unsigned Code = Stream.ReadCode();
262    if (Code == bitc::END_BLOCK) {
263      if (NumRecords != TypeList.size())
264        return Error("Invalid type forward reference in TYPE_BLOCK");
265      if (Stream.ReadBlockEnd())
266        return Error("Error at end of type table block");
267      return false;
268    }
269
270    if (Code == bitc::ENTER_SUBBLOCK) {
271      // No known subblocks, always skip them.
272      Stream.ReadSubBlockID();
273      if (Stream.SkipBlock())
274        return Error("Malformed block record");
275      continue;
276    }
277
278    if (Code == bitc::DEFINE_ABBREV) {
279      Stream.ReadAbbrevRecord();
280      continue;
281    }
282
283    // Read a record.
284    Record.clear();
285    const Type *ResultTy = 0;
286    switch (Stream.ReadRecord(Code, Record)) {
287    default:  // Default behavior: unknown type.
288      ResultTy = 0;
289      break;
290    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
291      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
292      // type list.  This allows us to reserve space.
293      if (Record.size() < 1)
294        return Error("Invalid TYPE_CODE_NUMENTRY record");
295      TypeList.reserve(Record[0]);
296      continue;
297    case bitc::TYPE_CODE_VOID:      // VOID
298      ResultTy = Type::VoidTy;
299      break;
300    case bitc::TYPE_CODE_FLOAT:     // FLOAT
301      ResultTy = Type::FloatTy;
302      break;
303    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
304      ResultTy = Type::DoubleTy;
305      break;
306    case bitc::TYPE_CODE_LABEL:     // LABEL
307      ResultTy = Type::LabelTy;
308      break;
309    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
310      ResultTy = 0;
311      break;
312    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
313      if (Record.size() < 1)
314        return Error("Invalid Integer type record");
315
316      ResultTy = IntegerType::get(Record[0]);
317      break;
318    case bitc::TYPE_CODE_POINTER:   // POINTER: [pointee type]
319      if (Record.size() < 1)
320        return Error("Invalid POINTER type record");
321      ResultTy = PointerType::get(getTypeByID(Record[0], true));
322      break;
323    case bitc::TYPE_CODE_FUNCTION: {
324      // FUNCTION: [vararg, attrid, retty, paramty x N]
325      if (Record.size() < 3)
326        return Error("Invalid FUNCTION type record");
327      std::vector<const Type*> ArgTys;
328      for (unsigned i = 3, e = Record.size(); i != e; ++i)
329        ArgTys.push_back(getTypeByID(Record[i], true));
330
331      ResultTy = FunctionType::get(getTypeByID(Record[2], true), ArgTys,
332                                   Record[0], getParamAttrs(Record[1]));
333      break;
334    }
335    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, eltty x N]
336      if (Record.size() < 1)
337        return Error("Invalid STRUCT type record");
338      std::vector<const Type*> EltTys;
339      for (unsigned i = 1, e = Record.size(); i != e; ++i)
340        EltTys.push_back(getTypeByID(Record[i], true));
341      ResultTy = StructType::get(EltTys, Record[0]);
342      break;
343    }
344    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
345      if (Record.size() < 2)
346        return Error("Invalid ARRAY type record");
347      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
348      break;
349    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
350      if (Record.size() < 2)
351        return Error("Invalid VECTOR type record");
352      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
353      break;
354    }
355
356    if (NumRecords == TypeList.size()) {
357      // If this is a new type slot, just append it.
358      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
359      ++NumRecords;
360    } else if (ResultTy == 0) {
361      // Otherwise, this was forward referenced, so an opaque type was created,
362      // but the result type is actually just an opaque.  Leave the one we
363      // created previously.
364      ++NumRecords;
365    } else {
366      // Otherwise, this was forward referenced, so an opaque type was created.
367      // Resolve the opaque type to the real type now.
368      assert(NumRecords < TypeList.size() && "Typelist imbalance");
369      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
370
371      // Don't directly push the new type on the Tab. Instead we want to replace
372      // the opaque type we previously inserted with the new concrete value. The
373      // refinement from the abstract (opaque) type to the new type causes all
374      // uses of the abstract type to use the concrete type (NewTy). This will
375      // also cause the opaque type to be deleted.
376      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
377
378      // This should have replaced the old opaque type with the new type in the
379      // value table... or with a preexisting type that was already in the
380      // system.  Let's just make sure it did.
381      assert(TypeList[NumRecords-1].get() != OldTy &&
382             "refineAbstractType didn't work!");
383    }
384  }
385}
386
387
388bool BitcodeReader::ParseTypeSymbolTable() {
389  if (Stream.EnterSubBlock(bitc::TYPE_SYMTAB_BLOCK_ID))
390    return Error("Malformed block record");
391
392  SmallVector<uint64_t, 64> Record;
393
394  // Read all the records for this type table.
395  std::string TypeName;
396  while (1) {
397    unsigned Code = Stream.ReadCode();
398    if (Code == bitc::END_BLOCK) {
399      if (Stream.ReadBlockEnd())
400        return Error("Error at end of type symbol table block");
401      return false;
402    }
403
404    if (Code == bitc::ENTER_SUBBLOCK) {
405      // No known subblocks, always skip them.
406      Stream.ReadSubBlockID();
407      if (Stream.SkipBlock())
408        return Error("Malformed block record");
409      continue;
410    }
411
412    if (Code == bitc::DEFINE_ABBREV) {
413      Stream.ReadAbbrevRecord();
414      continue;
415    }
416
417    // Read a record.
418    Record.clear();
419    switch (Stream.ReadRecord(Code, Record)) {
420    default:  // Default behavior: unknown type.
421      break;
422    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namechar x N]
423      if (ConvertToString(Record, 1, TypeName))
424        return Error("Invalid TST_ENTRY record");
425      unsigned TypeID = Record[0];
426      if (TypeID >= TypeList.size())
427        return Error("Invalid Type ID in TST_ENTRY record");
428
429      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
430      TypeName.clear();
431      break;
432    }
433  }
434}
435
436bool BitcodeReader::ParseValueSymbolTable() {
437  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
438    return Error("Malformed block record");
439
440  SmallVector<uint64_t, 64> Record;
441
442  // Read all the records for this value table.
443  SmallString<128> ValueName;
444  while (1) {
445    unsigned Code = Stream.ReadCode();
446    if (Code == bitc::END_BLOCK) {
447      if (Stream.ReadBlockEnd())
448        return Error("Error at end of value symbol table block");
449      return false;
450    }
451    if (Code == bitc::ENTER_SUBBLOCK) {
452      // No known subblocks, always skip them.
453      Stream.ReadSubBlockID();
454      if (Stream.SkipBlock())
455        return Error("Malformed block record");
456      continue;
457    }
458
459    if (Code == bitc::DEFINE_ABBREV) {
460      Stream.ReadAbbrevRecord();
461      continue;
462    }
463
464    // Read a record.
465    Record.clear();
466    switch (Stream.ReadRecord(Code, Record)) {
467    default:  // Default behavior: unknown type.
468      break;
469    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
470      if (ConvertToString(Record, 1, ValueName))
471        return Error("Invalid TST_ENTRY record");
472      unsigned ValueID = Record[0];
473      if (ValueID >= ValueList.size())
474        return Error("Invalid Value ID in VST_ENTRY record");
475      Value *V = ValueList[ValueID];
476
477      V->setName(&ValueName[0], ValueName.size());
478      ValueName.clear();
479      break;
480    }
481    case bitc::VST_CODE_BBENTRY: {
482      if (ConvertToString(Record, 1, ValueName))
483        return Error("Invalid VST_BBENTRY record");
484      BasicBlock *BB = getBasicBlock(Record[0]);
485      if (BB == 0)
486        return Error("Invalid BB ID in VST_BBENTRY record");
487
488      BB->setName(&ValueName[0], ValueName.size());
489      ValueName.clear();
490      break;
491    }
492    }
493  }
494}
495
496/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
497/// the LSB for dense VBR encoding.
498static uint64_t DecodeSignRotatedValue(uint64_t V) {
499  if ((V & 1) == 0)
500    return V >> 1;
501  if (V != 1)
502    return -(V >> 1);
503  // There is no such thing as -0 with integers.  "-0" really means MININT.
504  return 1ULL << 63;
505}
506
507/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
508/// values and aliases that we can.
509bool BitcodeReader::ResolveGlobalAndAliasInits() {
510  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
511  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
512
513  GlobalInitWorklist.swap(GlobalInits);
514  AliasInitWorklist.swap(AliasInits);
515
516  while (!GlobalInitWorklist.empty()) {
517    unsigned ValID = GlobalInitWorklist.back().second;
518    if (ValID >= ValueList.size()) {
519      // Not ready to resolve this yet, it requires something later in the file.
520      GlobalInits.push_back(GlobalInitWorklist.back());
521    } else {
522      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
523        GlobalInitWorklist.back().first->setInitializer(C);
524      else
525        return Error("Global variable initializer is not a constant!");
526    }
527    GlobalInitWorklist.pop_back();
528  }
529
530  while (!AliasInitWorklist.empty()) {
531    unsigned ValID = AliasInitWorklist.back().second;
532    if (ValID >= ValueList.size()) {
533      AliasInits.push_back(AliasInitWorklist.back());
534    } else {
535      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
536        AliasInitWorklist.back().first->setAliasee(C);
537      else
538        return Error("Alias initializer is not a constant!");
539    }
540    AliasInitWorklist.pop_back();
541  }
542  return false;
543}
544
545
546bool BitcodeReader::ParseConstants() {
547  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
548    return Error("Malformed block record");
549
550  SmallVector<uint64_t, 64> Record;
551
552  // Read all the records for this value table.
553  const Type *CurTy = Type::Int32Ty;
554  unsigned NextCstNo = ValueList.size();
555  while (1) {
556    unsigned Code = Stream.ReadCode();
557    if (Code == bitc::END_BLOCK) {
558      if (NextCstNo != ValueList.size())
559        return Error("Invalid constant reference!");
560
561      if (Stream.ReadBlockEnd())
562        return Error("Error at end of constants block");
563      return false;
564    }
565
566    if (Code == bitc::ENTER_SUBBLOCK) {
567      // No known subblocks, always skip them.
568      Stream.ReadSubBlockID();
569      if (Stream.SkipBlock())
570        return Error("Malformed block record");
571      continue;
572    }
573
574    if (Code == bitc::DEFINE_ABBREV) {
575      Stream.ReadAbbrevRecord();
576      continue;
577    }
578
579    // Read a record.
580    Record.clear();
581    Value *V = 0;
582    switch (Stream.ReadRecord(Code, Record)) {
583    default:  // Default behavior: unknown constant
584    case bitc::CST_CODE_UNDEF:     // UNDEF
585      V = UndefValue::get(CurTy);
586      break;
587    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
588      if (Record.empty())
589        return Error("Malformed CST_SETTYPE record");
590      if (Record[0] >= TypeList.size())
591        return Error("Invalid Type ID in CST_SETTYPE record");
592      CurTy = TypeList[Record[0]];
593      continue;  // Skip the ValueList manipulation.
594    case bitc::CST_CODE_NULL:      // NULL
595      V = Constant::getNullValue(CurTy);
596      break;
597    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
598      if (!isa<IntegerType>(CurTy) || Record.empty())
599        return Error("Invalid CST_INTEGER record");
600      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
601      break;
602    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
603      if (!isa<IntegerType>(CurTy) || Record.empty())
604        return Error("Invalid WIDE_INTEGER record");
605
606      unsigned NumWords = Record.size();
607      SmallVector<uint64_t, 8> Words;
608      Words.resize(NumWords);
609      for (unsigned i = 0; i != NumWords; ++i)
610        Words[i] = DecodeSignRotatedValue(Record[i]);
611      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
612                                 NumWords, &Words[0]));
613      break;
614    }
615    case bitc::CST_CODE_FLOAT:     // FLOAT: [fpval]
616      if (Record.empty())
617        return Error("Invalid FLOAT record");
618      if (CurTy == Type::FloatTy)
619        V = ConstantFP::get(CurTy, BitsToFloat(Record[0]));
620      else if (CurTy == Type::DoubleTy)
621        V = ConstantFP::get(CurTy, BitsToDouble(Record[0]));
622      else
623        V = UndefValue::get(CurTy);
624      break;
625
626    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
627      if (Record.empty())
628        return Error("Invalid CST_AGGREGATE record");
629
630      unsigned Size = Record.size();
631      std::vector<Constant*> Elts;
632
633      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
634        for (unsigned i = 0; i != Size; ++i)
635          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
636                                                     STy->getElementType(i)));
637        V = ConstantStruct::get(STy, Elts);
638      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
639        const Type *EltTy = ATy->getElementType();
640        for (unsigned i = 0; i != Size; ++i)
641          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
642        V = ConstantArray::get(ATy, Elts);
643      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
644        const Type *EltTy = VTy->getElementType();
645        for (unsigned i = 0; i != Size; ++i)
646          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
647        V = ConstantVector::get(Elts);
648      } else {
649        V = UndefValue::get(CurTy);
650      }
651      break;
652    }
653    case bitc::CST_CODE_STRING: { // STRING: [values]
654      if (Record.empty())
655        return Error("Invalid CST_AGGREGATE record");
656
657      const ArrayType *ATy = cast<ArrayType>(CurTy);
658      const Type *EltTy = ATy->getElementType();
659
660      unsigned Size = Record.size();
661      std::vector<Constant*> Elts;
662      for (unsigned i = 0; i != Size; ++i)
663        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
664      V = ConstantArray::get(ATy, Elts);
665      break;
666    }
667    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
668      if (Record.empty())
669        return Error("Invalid CST_AGGREGATE record");
670
671      const ArrayType *ATy = cast<ArrayType>(CurTy);
672      const Type *EltTy = ATy->getElementType();
673
674      unsigned Size = Record.size();
675      std::vector<Constant*> Elts;
676      for (unsigned i = 0; i != Size; ++i)
677        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
678      Elts.push_back(Constant::getNullValue(EltTy));
679      V = ConstantArray::get(ATy, Elts);
680      break;
681    }
682    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
683      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
684      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
685      if (Opc < 0) {
686        V = UndefValue::get(CurTy);  // Unknown binop.
687      } else {
688        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
689        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
690        V = ConstantExpr::get(Opc, LHS, RHS);
691      }
692      break;
693    }
694    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
695      if (Record.size() < 3) return Error("Invalid CE_CAST record");
696      int Opc = GetDecodedCastOpcode(Record[0]);
697      if (Opc < 0) {
698        V = UndefValue::get(CurTy);  // Unknown cast.
699      } else {
700        const Type *OpTy = getTypeByID(Record[1]);
701        if (!OpTy) return Error("Invalid CE_CAST record");
702        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
703        V = ConstantExpr::getCast(Opc, Op, CurTy);
704      }
705      break;
706    }
707    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
708      if (Record.size() & 1) return Error("Invalid CE_GEP record");
709      SmallVector<Constant*, 16> Elts;
710      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
711        const Type *ElTy = getTypeByID(Record[i]);
712        if (!ElTy) return Error("Invalid CE_GEP record");
713        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
714      }
715      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
716      break;
717    }
718    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
719      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
720      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
721                                                              Type::Int1Ty),
722                                  ValueList.getConstantFwdRef(Record[1],CurTy),
723                                  ValueList.getConstantFwdRef(Record[2],CurTy));
724      break;
725    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
726      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
727      const VectorType *OpTy =
728        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
729      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
730      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
731      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
732                                                  OpTy->getElementType());
733      V = ConstantExpr::getExtractElement(Op0, Op1);
734      break;
735    }
736    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
737      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
738      if (Record.size() < 3 || OpTy == 0)
739        return Error("Invalid CE_INSERTELT record");
740      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
741      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
742                                                  OpTy->getElementType());
743      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
744      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
745      break;
746    }
747    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
748      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
749      if (Record.size() < 3 || OpTy == 0)
750        return Error("Invalid CE_INSERTELT record");
751      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
752      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
753      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
754      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
755      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
756      break;
757    }
758    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
759      if (Record.size() < 4) return Error("Invalid CE_CMP record");
760      const Type *OpTy = getTypeByID(Record[0]);
761      if (OpTy == 0) return Error("Invalid CE_CMP record");
762      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
763      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
764
765      if (OpTy->isFloatingPoint())
766        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
767      else
768        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
769      break;
770    }
771    case bitc::CST_CODE_INLINEASM: {
772      if (Record.size() < 2) return Error("Invalid INLINEASM record");
773      std::string AsmStr, ConstrStr;
774      bool HasSideEffects = Record[0];
775      unsigned AsmStrSize = Record[1];
776      if (2+AsmStrSize >= Record.size())
777        return Error("Invalid INLINEASM record");
778      unsigned ConstStrSize = Record[2+AsmStrSize];
779      if (3+AsmStrSize+ConstStrSize > Record.size())
780        return Error("Invalid INLINEASM record");
781
782      for (unsigned i = 0; i != AsmStrSize; ++i)
783        AsmStr += (char)Record[2+i];
784      for (unsigned i = 0; i != ConstStrSize; ++i)
785        ConstrStr += (char)Record[3+AsmStrSize+i];
786      const PointerType *PTy = cast<PointerType>(CurTy);
787      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
788                         AsmStr, ConstrStr, HasSideEffects);
789      break;
790    }
791    }
792
793    ValueList.AssignValue(V, NextCstNo);
794    ++NextCstNo;
795  }
796}
797
798/// RememberAndSkipFunctionBody - When we see the block for a function body,
799/// remember where it is and then skip it.  This lets us lazily deserialize the
800/// functions.
801bool BitcodeReader::RememberAndSkipFunctionBody() {
802  // Get the function we are talking about.
803  if (FunctionsWithBodies.empty())
804    return Error("Insufficient function protos");
805
806  Function *Fn = FunctionsWithBodies.back();
807  FunctionsWithBodies.pop_back();
808
809  // Save the current stream state.
810  uint64_t CurBit = Stream.GetCurrentBitNo();
811  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
812
813  // Set the functions linkage to GhostLinkage so we know it is lazily
814  // deserialized.
815  Fn->setLinkage(GlobalValue::GhostLinkage);
816
817  // Skip over the function block for now.
818  if (Stream.SkipBlock())
819    return Error("Malformed block record");
820  return false;
821}
822
823bool BitcodeReader::ParseModule(const std::string &ModuleID) {
824  // Reject multiple MODULE_BLOCK's in a single bitstream.
825  if (TheModule)
826    return Error("Multiple MODULE_BLOCKs in same stream");
827
828  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
829    return Error("Malformed block record");
830
831  // Otherwise, create the module.
832  TheModule = new Module(ModuleID);
833
834  SmallVector<uint64_t, 64> Record;
835  std::vector<std::string> SectionTable;
836
837  // Read all the records for this module.
838  while (!Stream.AtEndOfStream()) {
839    unsigned Code = Stream.ReadCode();
840    if (Code == bitc::END_BLOCK) {
841      if (Stream.ReadBlockEnd())
842        return Error("Error at end of module block");
843
844      // Patch the initializers for globals and aliases up.
845      ResolveGlobalAndAliasInits();
846      if (!GlobalInits.empty() || !AliasInits.empty())
847        return Error("Malformed global initializer set");
848      if (!FunctionsWithBodies.empty())
849        return Error("Too few function bodies found");
850
851      // Force deallocation of memory for these vectors to favor the client that
852      // want lazy deserialization.
853      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
854      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
855      std::vector<Function*>().swap(FunctionsWithBodies);
856      return false;
857    }
858
859    if (Code == bitc::ENTER_SUBBLOCK) {
860      switch (Stream.ReadSubBlockID()) {
861      default:  // Skip unknown content.
862        if (Stream.SkipBlock())
863          return Error("Malformed block record");
864        break;
865      case bitc::BLOCKINFO_BLOCK_ID:
866        if (Stream.ReadBlockInfoBlock())
867          return Error("Malformed BlockInfoBlock");
868        break;
869      case bitc::PARAMATTR_BLOCK_ID:
870        if (ParseParamAttrBlock())
871          return true;
872        break;
873      case bitc::TYPE_BLOCK_ID:
874        if (ParseTypeTable())
875          return true;
876        break;
877      case bitc::TYPE_SYMTAB_BLOCK_ID:
878        if (ParseTypeSymbolTable())
879          return true;
880        break;
881      case bitc::VALUE_SYMTAB_BLOCK_ID:
882        if (ParseValueSymbolTable())
883          return true;
884        break;
885      case bitc::CONSTANTS_BLOCK_ID:
886        if (ParseConstants() || ResolveGlobalAndAliasInits())
887          return true;
888        break;
889      case bitc::FUNCTION_BLOCK_ID:
890        // If this is the first function body we've seen, reverse the
891        // FunctionsWithBodies list.
892        if (!HasReversedFunctionsWithBodies) {
893          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
894          HasReversedFunctionsWithBodies = true;
895        }
896
897        if (RememberAndSkipFunctionBody())
898          return true;
899        break;
900      }
901      continue;
902    }
903
904    if (Code == bitc::DEFINE_ABBREV) {
905      Stream.ReadAbbrevRecord();
906      continue;
907    }
908
909    // Read a record.
910    switch (Stream.ReadRecord(Code, Record)) {
911    default: break;  // Default behavior, ignore unknown content.
912    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
913      if (Record.size() < 1)
914        return Error("Malformed MODULE_CODE_VERSION");
915      // Only version #0 is supported so far.
916      if (Record[0] != 0)
917        return Error("Unknown bitstream version!");
918      break;
919    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
920      std::string S;
921      if (ConvertToString(Record, 0, S))
922        return Error("Invalid MODULE_CODE_TRIPLE record");
923      TheModule->setTargetTriple(S);
924      break;
925    }
926    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
927      std::string S;
928      if (ConvertToString(Record, 0, S))
929        return Error("Invalid MODULE_CODE_DATALAYOUT record");
930      TheModule->setDataLayout(S);
931      break;
932    }
933    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
934      std::string S;
935      if (ConvertToString(Record, 0, S))
936        return Error("Invalid MODULE_CODE_ASM record");
937      TheModule->setModuleInlineAsm(S);
938      break;
939    }
940    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
941      std::string S;
942      if (ConvertToString(Record, 0, S))
943        return Error("Invalid MODULE_CODE_DEPLIB record");
944      TheModule->addLibrary(S);
945      break;
946    }
947    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
948      std::string S;
949      if (ConvertToString(Record, 0, S))
950        return Error("Invalid MODULE_CODE_SECTIONNAME record");
951      SectionTable.push_back(S);
952      break;
953    }
954    // GLOBALVAR: [type, isconst, initid,
955    //             linkage, alignment, section, visibility, threadlocal]
956    case bitc::MODULE_CODE_GLOBALVAR: {
957      if (Record.size() < 6)
958        return Error("Invalid MODULE_CODE_GLOBALVAR record");
959      const Type *Ty = getTypeByID(Record[0]);
960      if (!isa<PointerType>(Ty))
961        return Error("Global not a pointer type!");
962      Ty = cast<PointerType>(Ty)->getElementType();
963
964      bool isConstant = Record[1];
965      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
966      unsigned Alignment = (1 << Record[4]) >> 1;
967      std::string Section;
968      if (Record[5]) {
969        if (Record[5]-1 >= SectionTable.size())
970          return Error("Invalid section ID");
971        Section = SectionTable[Record[5]-1];
972      }
973      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
974      if (Record.size() > 6)
975        Visibility = GetDecodedVisibility(Record[6]);
976      bool isThreadLocal = false;
977      if (Record.size() > 7)
978        isThreadLocal = Record[7];
979
980      GlobalVariable *NewGV =
981        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule);
982      NewGV->setAlignment(Alignment);
983      if (!Section.empty())
984        NewGV->setSection(Section);
985      NewGV->setVisibility(Visibility);
986      NewGV->setThreadLocal(isThreadLocal);
987
988      ValueList.push_back(NewGV);
989
990      // Remember which value to use for the global initializer.
991      if (unsigned InitID = Record[2])
992        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
993      break;
994    }
995    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
996    //             alignment, section, visibility]
997    case bitc::MODULE_CODE_FUNCTION: {
998      if (Record.size() < 8)
999        return Error("Invalid MODULE_CODE_FUNCTION record");
1000      const Type *Ty = getTypeByID(Record[0]);
1001      if (!isa<PointerType>(Ty))
1002        return Error("Function not a pointer type!");
1003      const FunctionType *FTy =
1004        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1005      if (!FTy)
1006        return Error("Function not a pointer to function type!");
1007
1008      Function *Func = new Function(FTy, GlobalValue::ExternalLinkage,
1009                                    "", TheModule);
1010
1011      Func->setCallingConv(Record[1]);
1012      bool isProto = Record[2];
1013      Func->setLinkage(GetDecodedLinkage(Record[3]));
1014
1015      assert(Func->getFunctionType()->getParamAttrs() ==
1016             getParamAttrs(Record[4]));
1017
1018      Func->setAlignment((1 << Record[5]) >> 1);
1019      if (Record[6]) {
1020        if (Record[6]-1 >= SectionTable.size())
1021          return Error("Invalid section ID");
1022        Func->setSection(SectionTable[Record[6]-1]);
1023      }
1024      Func->setVisibility(GetDecodedVisibility(Record[7]));
1025
1026      ValueList.push_back(Func);
1027
1028      // If this is a function with a body, remember the prototype we are
1029      // creating now, so that we can match up the body with them later.
1030      if (!isProto)
1031        FunctionsWithBodies.push_back(Func);
1032      break;
1033    }
1034    // ALIAS: [alias type, aliasee val#, linkage]
1035    case bitc::MODULE_CODE_ALIAS: {
1036      if (Record.size() < 3)
1037        return Error("Invalid MODULE_ALIAS record");
1038      const Type *Ty = getTypeByID(Record[0]);
1039      if (!isa<PointerType>(Ty))
1040        return Error("Function not a pointer type!");
1041
1042      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1043                                           "", 0, TheModule);
1044      ValueList.push_back(NewGA);
1045      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1046      break;
1047    }
1048    /// MODULE_CODE_PURGEVALS: [numvals]
1049    case bitc::MODULE_CODE_PURGEVALS:
1050      // Trim down the value list to the specified size.
1051      if (Record.size() < 1 || Record[0] > ValueList.size())
1052        return Error("Invalid MODULE_PURGEVALS record");
1053      ValueList.shrinkTo(Record[0]);
1054      break;
1055    }
1056    Record.clear();
1057  }
1058
1059  return Error("Premature end of bitstream");
1060}
1061
1062
1063bool BitcodeReader::ParseBitcode() {
1064  TheModule = 0;
1065
1066  if (Buffer->getBufferSize() & 3)
1067    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1068
1069  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1070  Stream.init(BufPtr, BufPtr+Buffer->getBufferSize());
1071
1072  // Sniff for the signature.
1073  if (Stream.Read(8) != 'B' ||
1074      Stream.Read(8) != 'C' ||
1075      Stream.Read(4) != 0x0 ||
1076      Stream.Read(4) != 0xC ||
1077      Stream.Read(4) != 0xE ||
1078      Stream.Read(4) != 0xD)
1079    return Error("Invalid bitcode signature");
1080
1081  // We expect a number of well-defined blocks, though we don't necessarily
1082  // need to understand them all.
1083  while (!Stream.AtEndOfStream()) {
1084    unsigned Code = Stream.ReadCode();
1085
1086    if (Code != bitc::ENTER_SUBBLOCK)
1087      return Error("Invalid record at top-level");
1088
1089    unsigned BlockID = Stream.ReadSubBlockID();
1090
1091    // We only know the MODULE subblock ID.
1092    switch (BlockID) {
1093    case bitc::BLOCKINFO_BLOCK_ID:
1094      if (Stream.ReadBlockInfoBlock())
1095        return Error("Malformed BlockInfoBlock");
1096      break;
1097    case bitc::MODULE_BLOCK_ID:
1098      if (ParseModule(Buffer->getBufferIdentifier()))
1099        return true;
1100      break;
1101    default:
1102      if (Stream.SkipBlock())
1103        return Error("Malformed block record");
1104      break;
1105    }
1106  }
1107
1108  return false;
1109}
1110
1111
1112/// ParseFunctionBody - Lazily parse the specified function body block.
1113bool BitcodeReader::ParseFunctionBody(Function *F) {
1114  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1115    return Error("Malformed block record");
1116
1117  unsigned ModuleValueListSize = ValueList.size();
1118
1119  // Add all the function arguments to the value table.
1120  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1121    ValueList.push_back(I);
1122
1123  unsigned NextValueNo = ValueList.size();
1124  BasicBlock *CurBB = 0;
1125  unsigned CurBBNo = 0;
1126
1127  // Read all the records.
1128  SmallVector<uint64_t, 64> Record;
1129  while (1) {
1130    unsigned Code = Stream.ReadCode();
1131    if (Code == bitc::END_BLOCK) {
1132      if (Stream.ReadBlockEnd())
1133        return Error("Error at end of function block");
1134      break;
1135    }
1136
1137    if (Code == bitc::ENTER_SUBBLOCK) {
1138      switch (Stream.ReadSubBlockID()) {
1139      default:  // Skip unknown content.
1140        if (Stream.SkipBlock())
1141          return Error("Malformed block record");
1142        break;
1143      case bitc::CONSTANTS_BLOCK_ID:
1144        if (ParseConstants()) return true;
1145        NextValueNo = ValueList.size();
1146        break;
1147      case bitc::VALUE_SYMTAB_BLOCK_ID:
1148        if (ParseValueSymbolTable()) return true;
1149        break;
1150      }
1151      continue;
1152    }
1153
1154    if (Code == bitc::DEFINE_ABBREV) {
1155      Stream.ReadAbbrevRecord();
1156      continue;
1157    }
1158
1159    // Read a record.
1160    Record.clear();
1161    Instruction *I = 0;
1162    switch (Stream.ReadRecord(Code, Record)) {
1163    default: // Default behavior: reject
1164      return Error("Unknown instruction");
1165    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1166      if (Record.size() < 1 || Record[0] == 0)
1167        return Error("Invalid DECLAREBLOCKS record");
1168      // Create all the basic blocks for the function.
1169      FunctionBBs.resize(Record[0]);
1170      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1171        FunctionBBs[i] = new BasicBlock("", F);
1172      CurBB = FunctionBBs[0];
1173      continue;
1174
1175    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1176      unsigned OpNum = 0;
1177      Value *LHS, *RHS;
1178      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1179          getValue(Record, OpNum, LHS->getType(), RHS) ||
1180          OpNum+1 != Record.size())
1181        return Error("Invalid BINOP record");
1182
1183      int Opc = GetDecodedBinaryOpcode(Record[OpNum], LHS->getType());
1184      if (Opc == -1) return Error("Invalid BINOP record");
1185      I = BinaryOperator::create((Instruction::BinaryOps)Opc, LHS, RHS);
1186      break;
1187    }
1188    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
1189      unsigned OpNum = 0;
1190      Value *Op;
1191      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1192          OpNum+2 != Record.size())
1193        return Error("Invalid CAST record");
1194
1195      const Type *ResTy = getTypeByID(Record[OpNum]);
1196      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
1197      if (Opc == -1 || ResTy == 0)
1198        return Error("Invalid CAST record");
1199      I = CastInst::create((Instruction::CastOps)Opc, Op, ResTy);
1200      break;
1201    }
1202    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
1203      unsigned OpNum = 0;
1204      Value *BasePtr;
1205      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
1206        return Error("Invalid GEP record");
1207
1208      SmallVector<Value*, 16> GEPIdx;
1209      while (OpNum != Record.size()) {
1210        Value *Op;
1211        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1212          return Error("Invalid GEP record");
1213        GEPIdx.push_back(Op);
1214      }
1215
1216      I = new GetElementPtrInst(BasePtr, &GEPIdx[0], GEPIdx.size());
1217      break;
1218    }
1219
1220    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
1221      unsigned OpNum = 0;
1222      Value *TrueVal, *FalseVal, *Cond;
1223      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
1224          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
1225          getValue(Record, OpNum, Type::Int1Ty, Cond))
1226        return Error("Invalid SELECT record");
1227
1228      I = new SelectInst(Cond, TrueVal, FalseVal);
1229      break;
1230    }
1231
1232    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1233      unsigned OpNum = 0;
1234      Value *Vec, *Idx;
1235      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1236          getValue(Record, OpNum, Type::Int32Ty, Idx))
1237        return Error("Invalid EXTRACTELT record");
1238      I = new ExtractElementInst(Vec, Idx);
1239      break;
1240    }
1241
1242    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1243      unsigned OpNum = 0;
1244      Value *Vec, *Elt, *Idx;
1245      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1246          getValue(Record, OpNum,
1247                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
1248          getValue(Record, OpNum, Type::Int32Ty, Idx))
1249        return Error("Invalid INSERTELT record");
1250      I = new InsertElementInst(Vec, Elt, Idx);
1251      break;
1252    }
1253
1254    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
1255      unsigned OpNum = 0;
1256      Value *Vec1, *Vec2, *Mask;
1257      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
1258          getValue(Record, OpNum, Vec1->getType(), Vec2))
1259        return Error("Invalid SHUFFLEVEC record");
1260
1261      const Type *MaskTy =
1262        VectorType::get(Type::Int32Ty,
1263                        cast<VectorType>(Vec1->getType())->getNumElements());
1264
1265      if (getValue(Record, OpNum, MaskTy, Mask))
1266        return Error("Invalid SHUFFLEVEC record");
1267      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1268      break;
1269    }
1270
1271    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1272      unsigned OpNum = 0;
1273      Value *LHS, *RHS;
1274      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1275          getValue(Record, OpNum, LHS->getType(), RHS) ||
1276          OpNum+1 != Record.size())
1277        return Error("Invalid CMP record");
1278
1279      if (LHS->getType()->isFPOrFPVector())
1280        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1281      else
1282        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1283      break;
1284    }
1285
1286    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1287      if (Record.size() == 0) {
1288        I = new ReturnInst();
1289        break;
1290      } else {
1291        unsigned OpNum = 0;
1292        Value *Op;
1293        if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1294            OpNum != Record.size())
1295          return Error("Invalid RET record");
1296        I = new ReturnInst(Op);
1297        break;
1298      }
1299    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1300      if (Record.size() != 1 && Record.size() != 3)
1301        return Error("Invalid BR record");
1302      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1303      if (TrueDest == 0)
1304        return Error("Invalid BR record");
1305
1306      if (Record.size() == 1)
1307        I = new BranchInst(TrueDest);
1308      else {
1309        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1310        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1311        if (FalseDest == 0 || Cond == 0)
1312          return Error("Invalid BR record");
1313        I = new BranchInst(TrueDest, FalseDest, Cond);
1314      }
1315      break;
1316    }
1317    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1318      if (Record.size() < 3 || (Record.size() & 1) == 0)
1319        return Error("Invalid SWITCH record");
1320      const Type *OpTy = getTypeByID(Record[0]);
1321      Value *Cond = getFnValueByID(Record[1], OpTy);
1322      BasicBlock *Default = getBasicBlock(Record[2]);
1323      if (OpTy == 0 || Cond == 0 || Default == 0)
1324        return Error("Invalid SWITCH record");
1325      unsigned NumCases = (Record.size()-3)/2;
1326      SwitchInst *SI = new SwitchInst(Cond, Default, NumCases);
1327      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1328        ConstantInt *CaseVal =
1329          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1330        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1331        if (CaseVal == 0 || DestBB == 0) {
1332          delete SI;
1333          return Error("Invalid SWITCH record!");
1334        }
1335        SI->addCase(CaseVal, DestBB);
1336      }
1337      I = SI;
1338      break;
1339    }
1340
1341    case bitc::FUNC_CODE_INST_INVOKE: { // INVOKE: [cc,fnty, op0,op1,op2, ...]
1342      if (Record.size() < 4) return Error("Invalid INVOKE record");
1343      unsigned CCInfo = Record[1];
1344      BasicBlock *NormalBB = getBasicBlock(Record[2]);
1345      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
1346
1347      unsigned OpNum = 4;
1348      Value *Callee;
1349      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1350        return Error("Invalid INVOKE record");
1351
1352      const PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
1353      const FunctionType *FTy = !CalleeTy ? 0 :
1354        dyn_cast<FunctionType>(CalleeTy->getElementType());
1355
1356      // Check that the right number of fixed parameters are here.
1357      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
1358          Record.size() < OpNum+FTy->getNumParams())
1359        return Error("Invalid INVOKE record");
1360
1361      assert(FTy->getParamAttrs() == getParamAttrs(Record[0]));
1362
1363      SmallVector<Value*, 16> Ops;
1364      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1365        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1366        if (Ops.back() == 0) return Error("Invalid INVOKE record");
1367      }
1368
1369      if (!FTy->isVarArg()) {
1370        if (Record.size() != OpNum)
1371          return Error("Invalid INVOKE record");
1372      } else {
1373        // Read type/value pairs for varargs params.
1374        while (OpNum != Record.size()) {
1375          Value *Op;
1376          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1377            return Error("Invalid INVOKE record");
1378          Ops.push_back(Op);
1379        }
1380      }
1381
1382      I = new InvokeInst(Callee, NormalBB, UnwindBB, &Ops[0], Ops.size());
1383      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1384      break;
1385    }
1386    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1387      I = new UnwindInst();
1388      break;
1389    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1390      I = new UnreachableInst();
1391      break;
1392    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
1393      if (Record.size() < 1 || ((Record.size()-1)&1))
1394        return Error("Invalid PHI record");
1395      const Type *Ty = getTypeByID(Record[0]);
1396      if (!Ty) return Error("Invalid PHI record");
1397
1398      PHINode *PN = new PHINode(Ty);
1399      PN->reserveOperandSpace(Record.size()-1);
1400
1401      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
1402        Value *V = getFnValueByID(Record[1+i], Ty);
1403        BasicBlock *BB = getBasicBlock(Record[2+i]);
1404        if (!V || !BB) return Error("Invalid PHI record");
1405        PN->addIncoming(V, BB);
1406      }
1407      I = PN;
1408      break;
1409    }
1410
1411    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1412      if (Record.size() < 3)
1413        return Error("Invalid MALLOC record");
1414      const PointerType *Ty =
1415        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1416      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1417      unsigned Align = Record[2];
1418      if (!Ty || !Size) return Error("Invalid MALLOC record");
1419      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1420      break;
1421    }
1422    case bitc::FUNC_CODE_INST_FREE: { // FREE: [op, opty]
1423      unsigned OpNum = 0;
1424      Value *Op;
1425      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1426          OpNum != Record.size())
1427        return Error("Invalid FREE record");
1428      I = new FreeInst(Op);
1429      break;
1430    }
1431    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1432      if (Record.size() < 3)
1433        return Error("Invalid ALLOCA record");
1434      const PointerType *Ty =
1435        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1436      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1437      unsigned Align = Record[2];
1438      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1439      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1440      break;
1441    }
1442    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1443      unsigned OpNum = 0;
1444      Value *Op;
1445      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1446          OpNum+2 != Record.size())
1447        return Error("Invalid LOAD record");
1448
1449      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1450      break;
1451    }
1452    case bitc::FUNC_CODE_INST_STORE: { // STORE:[val, valty, ptr, align, vol]
1453      unsigned OpNum = 0;
1454      Value *Val, *Ptr;
1455      if (getValueTypePair(Record, OpNum, NextValueNo, Val) ||
1456          getValue(Record, OpNum, PointerType::get(Val->getType()), Ptr) ||
1457          OpNum+2 != Record.size())
1458        return Error("Invalid STORE record");
1459
1460      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1461      break;
1462    }
1463    case bitc::FUNC_CODE_INST_CALL: { // CALL: [cc, fnty, fnid, arg0, arg1...]
1464      if (Record.size() < 2)
1465        return Error("Invalid CALL record");
1466
1467      unsigned CCInfo = Record[1];
1468
1469      unsigned OpNum = 2;
1470      Value *Callee;
1471      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1472        return Error("Invalid CALL record");
1473
1474      const PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
1475      const FunctionType *FTy = 0;
1476      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1477      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
1478        return Error("Invalid CALL record");
1479
1480      assert(FTy->getParamAttrs() == getParamAttrs(Record[0]));
1481
1482      SmallVector<Value*, 16> Args;
1483      // Read the fixed params.
1484      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1485        Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1486        if (Args.back() == 0) return Error("Invalid CALL record");
1487      }
1488
1489      // Read type/value pairs for varargs params.
1490      if (!FTy->isVarArg()) {
1491        if (OpNum != Record.size())
1492          return Error("Invalid CALL record");
1493      } else {
1494        while (OpNum != Record.size()) {
1495          Value *Op;
1496          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1497            return Error("Invalid CALL record");
1498          Args.push_back(Op);
1499        }
1500      }
1501
1502      I = new CallInst(Callee, &Args[0], Args.size());
1503      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1504      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1505      break;
1506    }
1507    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1508      if (Record.size() < 3)
1509        return Error("Invalid VAARG record");
1510      const Type *OpTy = getTypeByID(Record[0]);
1511      Value *Op = getFnValueByID(Record[1], OpTy);
1512      const Type *ResTy = getTypeByID(Record[2]);
1513      if (!OpTy || !Op || !ResTy)
1514        return Error("Invalid VAARG record");
1515      I = new VAArgInst(Op, ResTy);
1516      break;
1517    }
1518    }
1519
1520    // Add instruction to end of current BB.  If there is no current BB, reject
1521    // this file.
1522    if (CurBB == 0) {
1523      delete I;
1524      return Error("Invalid instruction with no BB");
1525    }
1526    CurBB->getInstList().push_back(I);
1527
1528    // If this was a terminator instruction, move to the next block.
1529    if (isa<TerminatorInst>(I)) {
1530      ++CurBBNo;
1531      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1532    }
1533
1534    // Non-void values get registered in the value table for future use.
1535    if (I && I->getType() != Type::VoidTy)
1536      ValueList.AssignValue(I, NextValueNo++);
1537  }
1538
1539  // Check the function list for unresolved values.
1540  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1541    if (A->getParent() == 0) {
1542      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1543      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1544        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1545          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1546          delete A;
1547        }
1548      }
1549      return Error("Never resolved value found in function!");
1550    }
1551  }
1552
1553  // Trim the value list down to the size it was before we parsed this function.
1554  ValueList.shrinkTo(ModuleValueListSize);
1555  std::vector<BasicBlock*>().swap(FunctionBBs);
1556
1557  return false;
1558}
1559
1560//===----------------------------------------------------------------------===//
1561// ModuleProvider implementation
1562//===----------------------------------------------------------------------===//
1563
1564
1565bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1566  // If it already is material, ignore the request.
1567  if (!F->hasNotBeenReadFromBytecode()) return false;
1568
1569  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1570    DeferredFunctionInfo.find(F);
1571  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1572
1573  // Move the bit stream to the saved position of the deferred function body and
1574  // restore the real linkage type for the function.
1575  Stream.JumpToBit(DFII->second.first);
1576  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1577
1578  if (ParseFunctionBody(F)) {
1579    if (ErrInfo) *ErrInfo = ErrorString;
1580    return true;
1581  }
1582
1583  return false;
1584}
1585
1586void BitcodeReader::dematerializeFunction(Function *F) {
1587  // If this function isn't materialized, or if it is a proto, this is a noop.
1588  if (F->hasNotBeenReadFromBytecode() || F->isDeclaration())
1589    return;
1590
1591  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
1592
1593  // Just forget the function body, we can remat it later.
1594  F->deleteBody();
1595  F->setLinkage(GlobalValue::GhostLinkage);
1596}
1597
1598
1599Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
1600  for (DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1601       DeferredFunctionInfo.begin(), E = DeferredFunctionInfo.end(); I != E;
1602       ++I) {
1603    Function *F = I->first;
1604    if (F->hasNotBeenReadFromBytecode() &&
1605        materializeFunction(F, ErrInfo))
1606      return 0;
1607  }
1608  return TheModule;
1609}
1610
1611
1612/// This method is provided by the parent ModuleProvde class and overriden
1613/// here. It simply releases the module from its provided and frees up our
1614/// state.
1615/// @brief Release our hold on the generated module
1616Module *BitcodeReader::releaseModule(std::string *ErrInfo) {
1617  // Since we're losing control of this Module, we must hand it back complete
1618  Module *M = ModuleProvider::releaseModule(ErrInfo);
1619  FreeState();
1620  return M;
1621}
1622
1623
1624//===----------------------------------------------------------------------===//
1625// External interface
1626//===----------------------------------------------------------------------===//
1627
1628/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1629///
1630ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1631                                               std::string *ErrMsg) {
1632  BitcodeReader *R = new BitcodeReader(Buffer);
1633  if (R->ParseBitcode()) {
1634    if (ErrMsg)
1635      *ErrMsg = R->getErrorString();
1636
1637    // Don't let the BitcodeReader dtor delete 'Buffer'.
1638    R->releaseMemoryBuffer();
1639    delete R;
1640    return 0;
1641  }
1642  return R;
1643}
1644
1645/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
1646/// If an error occurs, return null and fill in *ErrMsg if non-null.
1647Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
1648  BitcodeReader *R;
1649  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
1650  if (!R) return 0;
1651
1652  // Read in the entire module.
1653  Module *M = R->materializeModule(ErrMsg);
1654
1655  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
1656  // there was an error.
1657  R->releaseMemoryBuffer();
1658
1659  // If there was no error, tell ModuleProvider not to delete it when its dtor
1660  // is run.
1661  if (M)
1662    M = R->releaseModule(ErrMsg);
1663
1664  delete R;
1665  return M;
1666}
1667