BitcodeReader.cpp revision 48c85b84c1b66fb6a1b0d2afddf33da5bd82960d 
1//===- BitcodeReader.cpp - Internal BitcodeReader implementation ----------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by Chris Lattner and is distributed under
6// the University of Illinois Open Source License.  See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This header defines the BitcodeReader class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Bitcode/ReaderWriter.h"
15#include "BitcodeReader.h"
16#include "llvm/Constants.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/Instructions.h"
19#include "llvm/Module.h"
20#include "llvm/ParameterAttributes.h"
21#include "llvm/ADT/SmallString.h"
22#include "llvm/Support/MathExtras.h"
23#include "llvm/Support/MemoryBuffer.h"
24using namespace llvm;
25
26BitcodeReader::~BitcodeReader() {
27  delete Buffer;
28}
29
30//===----------------------------------------------------------------------===//
31//  Helper functions to implement forward reference resolution, etc.
32//===----------------------------------------------------------------------===//
33
34/// ConvertToString - Convert a string from a record into an std::string, return
35/// true on failure.
36template<typename StrTy>
37static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
38                            StrTy &Result) {
39  if (Record.size() < Idx+1 || Record.size() < Record[Idx]+Idx+1)
40    return true;
41
42  for (unsigned i = 0, e = Record[Idx]; i != e; ++i)
43    Result += (char)Record[Idx+i+1];
44  return false;
45}
46
47static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
48  switch (Val) {
49  default: // Map unknown/new linkages to external
50  case 0: return GlobalValue::ExternalLinkage;
51  case 1: return GlobalValue::WeakLinkage;
52  case 2: return GlobalValue::AppendingLinkage;
53  case 3: return GlobalValue::InternalLinkage;
54  case 4: return GlobalValue::LinkOnceLinkage;
55  case 5: return GlobalValue::DLLImportLinkage;
56  case 6: return GlobalValue::DLLExportLinkage;
57  case 7: return GlobalValue::ExternalWeakLinkage;
58  }
59}
60
61static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
62  switch (Val) {
63  default: // Map unknown visibilities to default.
64  case 0: return GlobalValue::DefaultVisibility;
65  case 1: return GlobalValue::HiddenVisibility;
66  case 2: return GlobalValue::ProtectedVisibility;
67  }
68}
69
70static int GetDecodedCastOpcode(unsigned Val) {
71  switch (Val) {
72  default: return -1;
73  case bitc::CAST_TRUNC   : return Instruction::Trunc;
74  case bitc::CAST_ZEXT    : return Instruction::ZExt;
75  case bitc::CAST_SEXT    : return Instruction::SExt;
76  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
77  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
78  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
79  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
80  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
81  case bitc::CAST_FPEXT   : return Instruction::FPExt;
82  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
83  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
84  case bitc::CAST_BITCAST : return Instruction::BitCast;
85  }
86}
87static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
88  switch (Val) {
89  default: return -1;
90  case bitc::BINOP_ADD:  return Instruction::Add;
91  case bitc::BINOP_SUB:  return Instruction::Sub;
92  case bitc::BINOP_MUL:  return Instruction::Mul;
93  case bitc::BINOP_UDIV: return Instruction::UDiv;
94  case bitc::BINOP_SDIV:
95    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
96  case bitc::BINOP_UREM: return Instruction::URem;
97  case bitc::BINOP_SREM:
98    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
99  case bitc::BINOP_SHL:  return Instruction::Shl;
100  case bitc::BINOP_LSHR: return Instruction::LShr;
101  case bitc::BINOP_ASHR: return Instruction::AShr;
102  case bitc::BINOP_AND:  return Instruction::And;
103  case bitc::BINOP_OR:   return Instruction::Or;
104  case bitc::BINOP_XOR:  return Instruction::Xor;
105  }
106}
107
108
109namespace {
110  /// @brief A class for maintaining the slot number definition
111  /// as a placeholder for the actual definition for forward constants defs.
112  class ConstantPlaceHolder : public ConstantExpr {
113    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
114    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
115  public:
116    Use Op;
117    ConstantPlaceHolder(const Type *Ty)
118      : ConstantExpr(Ty, Instruction::UserOp1, &Op, 1),
119        Op(UndefValue::get(Type::Int32Ty), this) {
120    }
121  };
122}
123
124Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
125                                                    const Type *Ty) {
126  if (Idx >= size()) {
127    // Insert a bunch of null values.
128    Uses.resize(Idx+1);
129    OperandList = &Uses[0];
130    NumOperands = Idx+1;
131  }
132
133  if (Value *V = Uses[Idx]) {
134    assert(Ty == V->getType() && "Type mismatch in constant table!");
135    return cast<Constant>(V);
136  }
137
138  // Create and return a placeholder, which will later be RAUW'd.
139  Constant *C = new ConstantPlaceHolder(Ty);
140  Uses[Idx].init(C, this);
141  return C;
142}
143
144Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
145  if (Idx >= size()) {
146    // Insert a bunch of null values.
147    Uses.resize(Idx+1);
148    OperandList = &Uses[0];
149    NumOperands = Idx+1;
150  }
151
152  if (Value *V = Uses[Idx]) {
153    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
154    return V;
155  }
156
157  // No type specified, must be invalid reference.
158  if (Ty == 0) return 0;
159
160  // Create and return a placeholder, which will later be RAUW'd.
161  Value *V = new Argument(Ty);
162  Uses[Idx].init(V, this);
163  return V;
164}
165
166
167const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
168  // If the TypeID is in range, return it.
169  if (ID < TypeList.size())
170    return TypeList[ID].get();
171  if (!isTypeTable) return 0;
172
173  // The type table allows forward references.  Push as many Opaque types as
174  // needed to get up to ID.
175  while (TypeList.size() <= ID)
176    TypeList.push_back(OpaqueType::get());
177  return TypeList.back().get();
178}
179
180//===----------------------------------------------------------------------===//
181//  Functions for parsing blocks from the bitcode file
182//===----------------------------------------------------------------------===//
183
184bool BitcodeReader::ParseParamAttrBlock() {
185  if (Stream.EnterSubBlock())
186    return Error("Malformed block record");
187
188  if (!ParamAttrs.empty())
189    return Error("Multiple PARAMATTR blocks found!");
190
191  SmallVector<uint64_t, 64> Record;
192
193  ParamAttrsVector Attrs;
194
195  // Read all the records.
196  while (1) {
197    unsigned Code = Stream.ReadCode();
198    if (Code == bitc::END_BLOCK) {
199      if (Stream.ReadBlockEnd())
200        return Error("Error at end of PARAMATTR block");
201      return false;
202    }
203
204    if (Code == bitc::ENTER_SUBBLOCK) {
205      // No known subblocks, always skip them.
206      Stream.ReadSubBlockID();
207      if (Stream.SkipBlock())
208        return Error("Malformed block record");
209      continue;
210    }
211
212    if (Code == bitc::DEFINE_ABBREV) {
213      Stream.ReadAbbrevRecord();
214      continue;
215    }
216
217    // Read a record.
218    Record.clear();
219    switch (Stream.ReadRecord(Code, Record)) {
220    default:  // Default behavior: ignore.
221      break;
222    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
223      if (Record.size() & 1)
224        return Error("Invalid ENTRY record");
225
226      ParamAttrsWithIndex PAWI;
227      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
228        PAWI.index = Record[i];
229        PAWI.attrs = Record[i+1];
230        Attrs.push_back(PAWI);
231      }
232      ParamAttrs.push_back(ParamAttrsList::get(Attrs));
233      Attrs.clear();
234      break;
235    }
236    }
237  }
238}
239
240
241bool BitcodeReader::ParseTypeTable() {
242  if (Stream.EnterSubBlock())
243    return Error("Malformed block record");
244
245  if (!TypeList.empty())
246    return Error("Multiple TYPE_BLOCKs found!");
247
248  SmallVector<uint64_t, 64> Record;
249  unsigned NumRecords = 0;
250
251  // Read all the records for this type table.
252  while (1) {
253    unsigned Code = Stream.ReadCode();
254    if (Code == bitc::END_BLOCK) {
255      if (NumRecords != TypeList.size())
256        return Error("Invalid type forward reference in TYPE_BLOCK");
257      if (Stream.ReadBlockEnd())
258        return Error("Error at end of type table block");
259      return false;
260    }
261
262    if (Code == bitc::ENTER_SUBBLOCK) {
263      // No known subblocks, always skip them.
264      Stream.ReadSubBlockID();
265      if (Stream.SkipBlock())
266        return Error("Malformed block record");
267      continue;
268    }
269
270    if (Code == bitc::DEFINE_ABBREV) {
271      Stream.ReadAbbrevRecord();
272      continue;
273    }
274
275    // Read a record.
276    Record.clear();
277    const Type *ResultTy = 0;
278    switch (Stream.ReadRecord(Code, Record)) {
279    default:  // Default behavior: unknown type.
280      ResultTy = 0;
281      break;
282    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
283      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
284      // type list.  This allows us to reserve space.
285      if (Record.size() < 1)
286        return Error("Invalid TYPE_CODE_NUMENTRY record");
287      TypeList.reserve(Record[0]);
288      continue;
289    case bitc::TYPE_CODE_VOID:      // VOID
290      ResultTy = Type::VoidTy;
291      break;
292    case bitc::TYPE_CODE_FLOAT:     // FLOAT
293      ResultTy = Type::FloatTy;
294      break;
295    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
296      ResultTy = Type::DoubleTy;
297      break;
298    case bitc::TYPE_CODE_LABEL:     // LABEL
299      ResultTy = Type::LabelTy;
300      break;
301    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
302      ResultTy = 0;
303      break;
304    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
305      if (Record.size() < 1)
306        return Error("Invalid Integer type record");
307
308      ResultTy = IntegerType::get(Record[0]);
309      break;
310    case bitc::TYPE_CODE_POINTER:   // POINTER: [pointee type]
311      if (Record.size() < 1)
312        return Error("Invalid POINTER type record");
313      ResultTy = PointerType::get(getTypeByID(Record[0], true));
314      break;
315    case bitc::TYPE_CODE_FUNCTION: {
316      // FUNCTION: [vararg, retty, #pararms, paramty N]
317      if (Record.size() < 3 || Record.size() < Record[2]+3)
318        return Error("Invalid FUNCTION type record");
319      std::vector<const Type*> ArgTys;
320      for (unsigned i = 0, e = Record[2]; i != e; ++i)
321        ArgTys.push_back(getTypeByID(Record[3+i], true));
322
323      // FIXME: PARAM TYS.
324      ResultTy = FunctionType::get(getTypeByID(Record[1], true), ArgTys,
325                                   Record[0]);
326      break;
327    }
328    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, #elts, eltty x N]
329      if (Record.size() < 2 || Record.size() < Record[1]+2)
330        return Error("Invalid STRUCT type record");
331      std::vector<const Type*> EltTys;
332      for (unsigned i = 0, e = Record[1]; i != e; ++i)
333        EltTys.push_back(getTypeByID(Record[2+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())
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, namelen, 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())
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, namelen, 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())
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, n x intval]
596      if (!isa<IntegerType>(CurTy) || Record.empty() ||
597          Record.size() < Record[0]+1)
598        return Error("Invalid WIDE_INTEGER record");
599
600      unsigned NumWords = Record[0];
601      SmallVector<uint64_t, 8> Words;
602      Words.resize(NumWords);
603      for (unsigned i = 0; i != NumWords; ++i)
604        Words[i] = DecodeSignRotatedValue(Record[i+1]);
605      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
606                                 NumWords, &Words[0]));
607      break;
608    }
609    case bitc::CST_CODE_FLOAT:     // FLOAT: [fpval]
610      if (Record.empty())
611        return Error("Invalid FLOAT record");
612      if (CurTy == Type::FloatTy)
613        V = ConstantFP::get(CurTy, BitsToFloat(Record[0]));
614      else if (CurTy == Type::DoubleTy)
615        V = ConstantFP::get(CurTy, BitsToDouble(Record[0]));
616      else
617        V = UndefValue::get(CurTy);
618      break;
619
620    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n, n x value number]
621      if (Record.empty() || Record.size() < Record[0]+1)
622        return Error("Invalid CST_AGGREGATE record");
623
624      unsigned Size = Record[0];
625      std::vector<Constant*> Elts;
626
627      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
628        for (unsigned i = 0; i != Size; ++i)
629          Elts.push_back(ValueList.getConstantFwdRef(Record[i+1],
630                                                     STy->getElementType(i)));
631        V = ConstantStruct::get(STy, Elts);
632      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
633        const Type *EltTy = ATy->getElementType();
634        for (unsigned i = 0; i != Size; ++i)
635          Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], EltTy));
636        V = ConstantArray::get(ATy, Elts);
637      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
638        const Type *EltTy = VTy->getElementType();
639        for (unsigned i = 0; i != Size; ++i)
640          Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], EltTy));
641        V = ConstantVector::get(Elts);
642      } else {
643        V = UndefValue::get(CurTy);
644      }
645      break;
646    }
647
648    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
649      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
650      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
651      if (Opc < 0) {
652        V = UndefValue::get(CurTy);  // Unknown binop.
653      } else {
654        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
655        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
656        V = ConstantExpr::get(Opc, LHS, RHS);
657      }
658      break;
659    }
660    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
661      if (Record.size() < 3) return Error("Invalid CE_CAST record");
662      int Opc = GetDecodedCastOpcode(Record[0]);
663      if (Opc < 0) {
664        V = UndefValue::get(CurTy);  // Unknown cast.
665      } else {
666        const Type *OpTy = getTypeByID(Record[1]);
667        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
668        V = ConstantExpr::getCast(Opc, Op, CurTy);
669      }
670      break;
671    }
672    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
673      if ((Record.size() & 1) == 0) return Error("Invalid CE_GEP record");
674      SmallVector<Constant*, 16> Elts;
675      for (unsigned i = 1, e = Record.size(); i != e; i += 2) {
676        const Type *ElTy = getTypeByID(Record[i]);
677        if (!ElTy) return Error("Invalid CE_GEP record");
678        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
679      }
680      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
681      break;
682    }
683    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
684      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
685      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
686                                                              Type::Int1Ty),
687                                  ValueList.getConstantFwdRef(Record[1],CurTy),
688                                  ValueList.getConstantFwdRef(Record[2],CurTy));
689      break;
690    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
691      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
692      const VectorType *OpTy =
693        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
694      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
695      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
696      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
697                                                  OpTy->getElementType());
698      V = ConstantExpr::getExtractElement(Op0, Op1);
699      break;
700    }
701    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
702      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
703      if (Record.size() < 3 || OpTy == 0)
704        return Error("Invalid CE_INSERTELT record");
705      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
706      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
707                                                  OpTy->getElementType());
708      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
709      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
710      break;
711    }
712    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
713      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
714      if (Record.size() < 3 || OpTy == 0)
715        return Error("Invalid CE_INSERTELT record");
716      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
717      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
718      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
719      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
720      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
721      break;
722    }
723    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
724      if (Record.size() < 4) return Error("Invalid CE_CMP record");
725      const Type *OpTy = getTypeByID(Record[0]);
726      if (OpTy == 0) return Error("Invalid CE_CMP record");
727      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
728      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
729
730      if (OpTy->isFloatingPoint())
731        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
732      else
733        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
734      break;
735    }
736    }
737
738    ValueList.AssignValue(V, NextCstNo);
739    ++NextCstNo;
740  }
741}
742
743/// RememberAndSkipFunctionBody - When we see the block for a function body,
744/// remember where it is and then skip it.  This lets us lazily deserialize the
745/// functions.
746bool BitcodeReader::RememberAndSkipFunctionBody() {
747  // Get the function we are talking about.
748  if (FunctionsWithBodies.empty())
749    return Error("Insufficient function protos");
750
751  Function *Fn = FunctionsWithBodies.back();
752  FunctionsWithBodies.pop_back();
753
754  // Save the current stream state.
755  uint64_t CurBit = Stream.GetCurrentBitNo();
756  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
757
758  // Set the functions linkage to GhostLinkage so we know it is lazily
759  // deserialized.
760  Fn->setLinkage(GlobalValue::GhostLinkage);
761
762  // Skip over the function block for now.
763  if (Stream.SkipBlock())
764    return Error("Malformed block record");
765  return false;
766}
767
768bool BitcodeReader::ParseModule(const std::string &ModuleID) {
769  // Reject multiple MODULE_BLOCK's in a single bitstream.
770  if (TheModule)
771    return Error("Multiple MODULE_BLOCKs in same stream");
772
773  if (Stream.EnterSubBlock())
774    return Error("Malformed block record");
775
776  // Otherwise, create the module.
777  TheModule = new Module(ModuleID);
778
779  SmallVector<uint64_t, 64> Record;
780  std::vector<std::string> SectionTable;
781
782  // Read all the records for this module.
783  while (!Stream.AtEndOfStream()) {
784    unsigned Code = Stream.ReadCode();
785    if (Code == bitc::END_BLOCK) {
786      if (Stream.ReadBlockEnd())
787        return Error("Error at end of module block");
788
789      // Patch the initializers for globals and aliases up.
790      ResolveGlobalAndAliasInits();
791      if (!GlobalInits.empty() || !AliasInits.empty())
792        return Error("Malformed global initializer set");
793      if (!FunctionsWithBodies.empty())
794        return Error("Too few function bodies found");
795
796      // Force deallocation of memory for these vectors to favor the client that
797      // want lazy deserialization.
798      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
799      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
800      std::vector<Function*>().swap(FunctionsWithBodies);
801      return false;
802    }
803
804    if (Code == bitc::ENTER_SUBBLOCK) {
805      switch (Stream.ReadSubBlockID()) {
806      default:  // Skip unknown content.
807        if (Stream.SkipBlock())
808          return Error("Malformed block record");
809        break;
810      case bitc::PARAMATTR_BLOCK_ID:
811        if (ParseParamAttrBlock())
812          return true;
813        break;
814      case bitc::TYPE_BLOCK_ID:
815        if (ParseTypeTable())
816          return true;
817        break;
818      case bitc::TYPE_SYMTAB_BLOCK_ID:
819        if (ParseTypeSymbolTable())
820          return true;
821        break;
822      case bitc::VALUE_SYMTAB_BLOCK_ID:
823        if (ParseValueSymbolTable())
824          return true;
825        break;
826      case bitc::CONSTANTS_BLOCK_ID:
827        if (ParseConstants() || ResolveGlobalAndAliasInits())
828          return true;
829        break;
830      case bitc::FUNCTION_BLOCK_ID:
831        // If this is the first function body we've seen, reverse the
832        // FunctionsWithBodies list.
833        if (!HasReversedFunctionsWithBodies) {
834          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
835          HasReversedFunctionsWithBodies = true;
836        }
837
838        if (RememberAndSkipFunctionBody())
839          return true;
840        break;
841      }
842      continue;
843    }
844
845    if (Code == bitc::DEFINE_ABBREV) {
846      Stream.ReadAbbrevRecord();
847      continue;
848    }
849
850    // Read a record.
851    switch (Stream.ReadRecord(Code, Record)) {
852    default: break;  // Default behavior, ignore unknown content.
853    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
854      if (Record.size() < 1)
855        return Error("Malformed MODULE_CODE_VERSION");
856      // Only version #0 is supported so far.
857      if (Record[0] != 0)
858        return Error("Unknown bitstream version!");
859      break;
860    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strlen, strchr x N]
861      std::string S;
862      if (ConvertToString(Record, 0, S))
863        return Error("Invalid MODULE_CODE_TRIPLE record");
864      TheModule->setTargetTriple(S);
865      break;
866    }
867    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strlen, strchr x N]
868      std::string S;
869      if (ConvertToString(Record, 0, S))
870        return Error("Invalid MODULE_CODE_DATALAYOUT record");
871      TheModule->setDataLayout(S);
872      break;
873    }
874    case bitc::MODULE_CODE_ASM: {  // ASM: [strlen, strchr x N]
875      std::string S;
876      if (ConvertToString(Record, 0, S))
877        return Error("Invalid MODULE_CODE_ASM record");
878      TheModule->setModuleInlineAsm(S);
879      break;
880    }
881    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strlen, strchr x N]
882      std::string S;
883      if (ConvertToString(Record, 0, S))
884        return Error("Invalid MODULE_CODE_DEPLIB record");
885      TheModule->addLibrary(S);
886      break;
887    }
888    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strlen, strchr x N]
889      std::string S;
890      if (ConvertToString(Record, 0, S))
891        return Error("Invalid MODULE_CODE_SECTIONNAME record");
892      SectionTable.push_back(S);
893      break;
894    }
895    // GLOBALVAR: [type, isconst, initid,
896    //             linkage, alignment, section, visibility, threadlocal]
897    case bitc::MODULE_CODE_GLOBALVAR: {
898      if (Record.size() < 6)
899        return Error("Invalid MODULE_CODE_GLOBALVAR record");
900      const Type *Ty = getTypeByID(Record[0]);
901      if (!isa<PointerType>(Ty))
902        return Error("Global not a pointer type!");
903      Ty = cast<PointerType>(Ty)->getElementType();
904
905      bool isConstant = Record[1];
906      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
907      unsigned Alignment = (1 << Record[4]) >> 1;
908      std::string Section;
909      if (Record[5]) {
910        if (Record[5]-1 >= SectionTable.size())
911          return Error("Invalid section ID");
912        Section = SectionTable[Record[5]-1];
913      }
914      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
915      if (Record.size() >= 6) Visibility = GetDecodedVisibility(Record[6]);
916      bool isThreadLocal = false;
917      if (Record.size() >= 7) isThreadLocal = Record[7];
918
919      GlobalVariable *NewGV =
920        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule);
921      NewGV->setAlignment(Alignment);
922      if (!Section.empty())
923        NewGV->setSection(Section);
924      NewGV->setVisibility(Visibility);
925      NewGV->setThreadLocal(isThreadLocal);
926
927      ValueList.push_back(NewGV);
928
929      // Remember which value to use for the global initializer.
930      if (unsigned InitID = Record[2])
931        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
932      break;
933    }
934    // FUNCTION:  [type, callingconv, isproto, linkage, alignment, section,
935    //             visibility]
936    case bitc::MODULE_CODE_FUNCTION: {
937      if (Record.size() < 7)
938        return Error("Invalid MODULE_CODE_FUNCTION record");
939      const Type *Ty = getTypeByID(Record[0]);
940      if (!isa<PointerType>(Ty))
941        return Error("Function not a pointer type!");
942      const FunctionType *FTy =
943        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
944      if (!FTy)
945        return Error("Function not a pointer to function type!");
946
947      Function *Func = new Function(FTy, GlobalValue::ExternalLinkage,
948                                    "", TheModule);
949
950      Func->setCallingConv(Record[1]);
951      bool isProto = Record[2];
952      Func->setLinkage(GetDecodedLinkage(Record[3]));
953      Func->setAlignment((1 << Record[4]) >> 1);
954      if (Record[5]) {
955        if (Record[5]-1 >= SectionTable.size())
956          return Error("Invalid section ID");
957        Func->setSection(SectionTable[Record[5]-1]);
958      }
959      Func->setVisibility(GetDecodedVisibility(Record[6]));
960
961      ValueList.push_back(Func);
962
963      // If this is a function with a body, remember the prototype we are
964      // creating now, so that we can match up the body with them later.
965      if (!isProto)
966        FunctionsWithBodies.push_back(Func);
967      break;
968    }
969    // ALIAS: [alias type, aliasee val#, linkage]
970    case bitc::MODULE_CODE_ALIAS: {
971      if (Record.size() < 3)
972        return Error("Invalid MODULE_ALIAS record");
973      const Type *Ty = getTypeByID(Record[0]);
974      if (!isa<PointerType>(Ty))
975        return Error("Function not a pointer type!");
976
977      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
978                                           "", 0, TheModule);
979      ValueList.push_back(NewGA);
980      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
981      break;
982    }
983    /// MODULE_CODE_PURGEVALS: [numvals]
984    case bitc::MODULE_CODE_PURGEVALS:
985      // Trim down the value list to the specified size.
986      if (Record.size() < 1 || Record[0] > ValueList.size())
987        return Error("Invalid MODULE_PURGEVALS record");
988      ValueList.shrinkTo(Record[0]);
989      break;
990    }
991    Record.clear();
992  }
993
994  return Error("Premature end of bitstream");
995}
996
997
998bool BitcodeReader::ParseBitcode() {
999  TheModule = 0;
1000
1001  if (Buffer->getBufferSize() & 3)
1002    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1003
1004  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1005  Stream.init(BufPtr, BufPtr+Buffer->getBufferSize());
1006
1007  // Sniff for the signature.
1008  if (Stream.Read(8) != 'B' ||
1009      Stream.Read(8) != 'C' ||
1010      Stream.Read(4) != 0x0 ||
1011      Stream.Read(4) != 0xC ||
1012      Stream.Read(4) != 0xE ||
1013      Stream.Read(4) != 0xD)
1014    return Error("Invalid bitcode signature");
1015
1016  // We expect a number of well-defined blocks, though we don't necessarily
1017  // need to understand them all.
1018  while (!Stream.AtEndOfStream()) {
1019    unsigned Code = Stream.ReadCode();
1020
1021    if (Code != bitc::ENTER_SUBBLOCK)
1022      return Error("Invalid record at top-level");
1023
1024    unsigned BlockID = Stream.ReadSubBlockID();
1025
1026    // We only know the MODULE subblock ID.
1027    if (BlockID == bitc::MODULE_BLOCK_ID) {
1028      if (ParseModule(Buffer->getBufferIdentifier()))
1029        return true;
1030    } else if (Stream.SkipBlock()) {
1031      return Error("Malformed block record");
1032    }
1033  }
1034
1035  return false;
1036}
1037
1038
1039bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1040  // If it already is material, ignore the request.
1041  if (!F->hasNotBeenReadFromBytecode()) return false;
1042
1043  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1044    DeferredFunctionInfo.find(F);
1045  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1046
1047  // Move the bit stream to the saved position of the deferred function body and
1048  // restore the real linkage type for the function.
1049  Stream.JumpToBit(DFII->second.first);
1050  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1051  DeferredFunctionInfo.erase(DFII);
1052
1053  if (ParseFunctionBody(F)) {
1054    if (ErrInfo) *ErrInfo = ErrorString;
1055    return true;
1056  }
1057
1058  return false;
1059}
1060
1061Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
1062  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1063    DeferredFunctionInfo.begin();
1064  while (!DeferredFunctionInfo.empty()) {
1065    Function *F = (*I++).first;
1066    assert(F->hasNotBeenReadFromBytecode() &&
1067           "Deserialized function found in map!");
1068    if (materializeFunction(F, ErrInfo))
1069      return 0;
1070  }
1071  return TheModule;
1072}
1073
1074
1075/// ParseFunctionBody - Lazily parse the specified function body block.
1076bool BitcodeReader::ParseFunctionBody(Function *F) {
1077  if (Stream.EnterSubBlock())
1078    return Error("Malformed block record");
1079
1080  unsigned ModuleValueListSize = ValueList.size();
1081
1082  // Add all the function arguments to the value table.
1083  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1084    ValueList.push_back(I);
1085
1086  unsigned NextValueNo = ValueList.size();
1087  BasicBlock *CurBB = 0;
1088  unsigned CurBBNo = 0;
1089
1090  // Read all the records.
1091  SmallVector<uint64_t, 64> Record;
1092  while (1) {
1093    unsigned Code = Stream.ReadCode();
1094    if (Code == bitc::END_BLOCK) {
1095      if (Stream.ReadBlockEnd())
1096        return Error("Error at end of function block");
1097      break;
1098    }
1099
1100    if (Code == bitc::ENTER_SUBBLOCK) {
1101      switch (Stream.ReadSubBlockID()) {
1102      default:  // Skip unknown content.
1103        if (Stream.SkipBlock())
1104          return Error("Malformed block record");
1105        break;
1106      case bitc::CONSTANTS_BLOCK_ID:
1107        if (ParseConstants()) return true;
1108        NextValueNo = ValueList.size();
1109        break;
1110      case bitc::VALUE_SYMTAB_BLOCK_ID:
1111        if (ParseValueSymbolTable()) return true;
1112        break;
1113      }
1114      continue;
1115    }
1116
1117    if (Code == bitc::DEFINE_ABBREV) {
1118      Stream.ReadAbbrevRecord();
1119      continue;
1120    }
1121
1122    // Read a record.
1123    Record.clear();
1124    Instruction *I = 0;
1125    switch (Stream.ReadRecord(Code, Record)) {
1126    default: // Default behavior: reject
1127      return Error("Unknown instruction");
1128    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1129      if (Record.size() < 1 || Record[0] == 0)
1130        return Error("Invalid DECLAREBLOCKS record");
1131      // Create all the basic blocks for the function.
1132      FunctionBBs.resize(Record[0]);
1133      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1134        FunctionBBs[i] = new BasicBlock("", F);
1135      CurBB = FunctionBBs[0];
1136      continue;
1137
1138    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opcode, ty, opval, opval]
1139      if (Record.size() < 4) return Error("Invalid BINOP record");
1140      const Type *Ty = getTypeByID(Record[1]);
1141      int Opc = GetDecodedBinaryOpcode(Record[0], Ty);
1142      Value *LHS = getFnValueByID(Record[2], Ty);
1143      Value *RHS = getFnValueByID(Record[3], Ty);
1144      if (Opc == -1 || Ty == 0 || LHS == 0 || RHS == 0)
1145         return Error("Invalid BINOP record");
1146      I = BinaryOperator::create((Instruction::BinaryOps)Opc, LHS, RHS);
1147      break;
1148    }
1149    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opcode, ty, opty, opval]
1150      if (Record.size() < 4) return Error("Invalid CAST record");
1151      int Opc = GetDecodedCastOpcode(Record[0]);
1152      const Type *ResTy = getTypeByID(Record[1]);
1153      const Type *OpTy = getTypeByID(Record[2]);
1154      Value *Op = getFnValueByID(Record[3], OpTy);
1155      if (Opc == -1 || ResTy == 0 || OpTy == 0 || Op == 0)
1156        return Error("Invalid CAST record");
1157      I = CastInst::create((Instruction::CastOps)Opc, Op, ResTy);
1158      break;
1159    }
1160    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n, n x operands]
1161      if (Record.size() < 2 || (Record.size() & 1))
1162        return Error("Invalid GEP record");
1163      const Type *OpTy = getTypeByID(Record[0]);
1164      Value *Op = getFnValueByID(Record[1], OpTy);
1165      if (OpTy == 0 || Op == 0)
1166        return Error("Invalid GEP record");
1167
1168      SmallVector<Value*, 16> GEPIdx;
1169      for (unsigned i = 1, e = Record.size()/2; i != e; ++i) {
1170        const Type *IdxTy = getTypeByID(Record[i*2]);
1171        Value *Idx = getFnValueByID(Record[i*2+1], IdxTy);
1172        if (IdxTy == 0 || Idx == 0)
1173          return Error("Invalid GEP record");
1174        GEPIdx.push_back(Idx);
1175      }
1176
1177      I = new GetElementPtrInst(Op, &GEPIdx[0], GEPIdx.size());
1178      break;
1179    }
1180
1181    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [ty, opval, opval, opval]
1182      if (Record.size() < 4) return Error("Invalid SELECT record");
1183      const Type *Ty = getTypeByID(Record[0]);
1184      Value *Cond = getFnValueByID(Record[1], Type::Int1Ty);
1185      Value *LHS = getFnValueByID(Record[2], Ty);
1186      Value *RHS = getFnValueByID(Record[3], Ty);
1187      if (Ty == 0 || Cond == 0 || LHS == 0 || RHS == 0)
1188        return Error("Invalid SELECT record");
1189      I = new SelectInst(Cond, LHS, RHS);
1190      break;
1191    }
1192
1193    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1194      if (Record.size() < 3) return Error("Invalid EXTRACTELT record");
1195      const Type *OpTy = getTypeByID(Record[0]);
1196      Value *Vec = getFnValueByID(Record[1], OpTy);
1197      Value *Idx = getFnValueByID(Record[2], Type::Int32Ty);
1198      if (OpTy == 0 || Vec == 0 || Idx == 0)
1199        return Error("Invalid EXTRACTELT record");
1200      I = new ExtractElementInst(Vec, Idx);
1201      break;
1202    }
1203
1204    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1205      if (Record.size() < 4) return Error("Invalid INSERTELT record");
1206      const VectorType *OpTy =
1207        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1208      if (OpTy == 0) return Error("Invalid INSERTELT record");
1209      Value *Vec = getFnValueByID(Record[1], OpTy);
1210      Value *Elt = getFnValueByID(Record[2], OpTy->getElementType());
1211      Value *Idx = getFnValueByID(Record[3], Type::Int32Ty);
1212      if (Vec == 0 || Elt == 0 || Idx == 0)
1213        return Error("Invalid INSERTELT record");
1214      I = new InsertElementInst(Vec, Elt, Idx);
1215      break;
1216    }
1217
1218    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [ty,opval,opval,opval]
1219      if (Record.size() < 4) return Error("Invalid SHUFFLEVEC record");
1220      const VectorType *OpTy =
1221        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1222      if (OpTy == 0) return Error("Invalid SHUFFLEVEC record");
1223      Value *Vec1 = getFnValueByID(Record[1], OpTy);
1224      Value *Vec2 = getFnValueByID(Record[2], OpTy);
1225      Value *Mask = getFnValueByID(Record[3],
1226                                   VectorType::get(Type::Int32Ty,
1227                                                   OpTy->getNumElements()));
1228      if (Vec1 == 0 || Vec2 == 0 || Mask == 0)
1229        return Error("Invalid SHUFFLEVEC record");
1230      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1231      break;
1232    }
1233
1234    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1235      if (Record.size() < 4) return Error("Invalid CMP record");
1236      const Type *OpTy = getTypeByID(Record[0]);
1237      Value *LHS = getFnValueByID(Record[1], OpTy);
1238      Value *RHS = getFnValueByID(Record[2], OpTy);
1239      if (OpTy == 0 || LHS == 0 || RHS == 0)
1240        return Error("Invalid CMP record");
1241      if (OpTy->isFPOrFPVector())
1242        I = new FCmpInst((FCmpInst::Predicate)Record[3], LHS, RHS);
1243      else
1244        I = new ICmpInst((ICmpInst::Predicate)Record[3], LHS, RHS);
1245      break;
1246    }
1247
1248    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1249      if (Record.size() == 0) {
1250        I = new ReturnInst();
1251        break;
1252      }
1253      if (Record.size() == 2) {
1254        const Type *OpTy = getTypeByID(Record[0]);
1255        Value *Op = getFnValueByID(Record[1], OpTy);
1256        if (!OpTy || !Op)
1257          return Error("Invalid RET record");
1258        I = new ReturnInst(Op);
1259        break;
1260      }
1261      return Error("Invalid RET record");
1262    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1263      if (Record.size() != 1 && Record.size() != 3)
1264        return Error("Invalid BR record");
1265      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1266      if (TrueDest == 0)
1267        return Error("Invalid BR record");
1268
1269      if (Record.size() == 1)
1270        I = new BranchInst(TrueDest);
1271      else {
1272        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1273        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1274        if (FalseDest == 0 || Cond == 0)
1275          return Error("Invalid BR record");
1276        I = new BranchInst(TrueDest, FalseDest, Cond);
1277      }
1278      break;
1279    }
1280    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1281      if (Record.size() < 3 || (Record.size() & 1) == 0)
1282        return Error("Invalid SWITCH record");
1283      const Type *OpTy = getTypeByID(Record[0]);
1284      Value *Cond = getFnValueByID(Record[1], OpTy);
1285      BasicBlock *Default = getBasicBlock(Record[2]);
1286      if (OpTy == 0 || Cond == 0 || Default == 0)
1287        return Error("Invalid SWITCH record");
1288      unsigned NumCases = (Record.size()-3)/2;
1289      SwitchInst *SI = new SwitchInst(Cond, Default, NumCases);
1290      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1291        ConstantInt *CaseVal =
1292          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1293        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1294        if (CaseVal == 0 || DestBB == 0) {
1295          delete SI;
1296          return Error("Invalid SWITCH record!");
1297        }
1298        SI->addCase(CaseVal, DestBB);
1299      }
1300      I = SI;
1301      break;
1302    }
1303
1304    case bitc::FUNC_CODE_INST_INVOKE: { // INVOKE: [cc,fnty, op0,op1,op2, ...]
1305      if (Record.size() < 5)
1306        return Error("Invalid INVOKE record");
1307      unsigned CCInfo = Record[0];
1308      const PointerType *CalleeTy =
1309        dyn_cast_or_null<PointerType>(getTypeByID(Record[1]));
1310      Value *Callee = getFnValueByID(Record[2], CalleeTy);
1311      BasicBlock *NormalBB = getBasicBlock(Record[3]);
1312      BasicBlock *UnwindBB = getBasicBlock(Record[4]);
1313      if (CalleeTy == 0 || Callee == 0 || NormalBB == 0 || UnwindBB == 0)
1314        return Error("Invalid INVOKE record");
1315
1316      const FunctionType *FTy =
1317        dyn_cast<FunctionType>(CalleeTy->getElementType());
1318
1319      // Check that the right number of fixed parameters are here.
1320      if (FTy == 0 || Record.size() < 5+FTy->getNumParams())
1321        return Error("Invalid INVOKE record");
1322
1323      SmallVector<Value*, 16> Ops;
1324      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1325        Ops.push_back(getFnValueByID(Record[5+i], FTy->getParamType(i)));
1326        if (Ops.back() == 0)
1327          return Error("Invalid INVOKE record");
1328      }
1329
1330      unsigned FirstVarargParam = 5+FTy->getNumParams();
1331      if (FTy->isVarArg()) {
1332        // Read type/value pairs for varargs params.
1333        if ((Record.size()-FirstVarargParam) & 1)
1334          return Error("Invalid INVOKE record");
1335
1336        for (unsigned i = FirstVarargParam, e = Record.size(); i != e; i += 2) {
1337          const Type *ArgTy = getTypeByID(Record[i]);
1338          Ops.push_back(getFnValueByID(Record[i+1], ArgTy));
1339          if (Ops.back() == 0 || ArgTy == 0)
1340            return Error("Invalid INVOKE record");
1341        }
1342      } else {
1343        if (Record.size() != FirstVarargParam)
1344          return Error("Invalid INVOKE record");
1345      }
1346
1347      I = new InvokeInst(Callee, NormalBB, UnwindBB, &Ops[0], Ops.size());
1348      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1349      break;
1350    }
1351    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1352      I = new UnwindInst();
1353      break;
1354    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1355      I = new UnreachableInst();
1356      break;
1357    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, #ops, val0,bb0, ...]
1358      if (Record.size() < 2 || Record.size() < 2+Record[1] || (Record[1]&1))
1359        return Error("Invalid PHI record");
1360      const Type *Ty = getTypeByID(Record[0]);
1361      if (!Ty) return Error("Invalid PHI record");
1362
1363      PHINode *PN = new PHINode(Ty);
1364      PN->reserveOperandSpace(Record[1]);
1365
1366      for (unsigned i = 0, e = Record[1]; i != e; i += 2) {
1367        Value *V = getFnValueByID(Record[2+i], Ty);
1368        BasicBlock *BB = getBasicBlock(Record[3+i]);
1369        if (!V || !BB) return Error("Invalid PHI record");
1370        PN->addIncoming(V, BB);
1371      }
1372      I = PN;
1373      break;
1374    }
1375
1376    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1377      if (Record.size() < 3)
1378        return Error("Invalid MALLOC record");
1379      const PointerType *Ty =
1380        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1381      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1382      unsigned Align = Record[2];
1383      if (!Ty || !Size) return Error("Invalid MALLOC record");
1384      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1385      break;
1386    }
1387    case bitc::FUNC_CODE_INST_FREE: { // FREE: [opty, op]
1388      if (Record.size() < 2)
1389        return Error("Invalid FREE record");
1390      const Type *OpTy = getTypeByID(Record[0]);
1391      Value *Op = getFnValueByID(Record[1], OpTy);
1392      if (!OpTy || !Op)
1393        return Error("Invalid FREE record");
1394      I = new FreeInst(Op);
1395      break;
1396    }
1397    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1398      if (Record.size() < 3)
1399        return Error("Invalid ALLOCA record");
1400      const PointerType *Ty =
1401        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1402      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1403      unsigned Align = Record[2];
1404      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1405      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1406      break;
1407    }
1408    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1409      if (Record.size() < 4)
1410        return Error("Invalid LOAD record");
1411      const Type *OpTy = getTypeByID(Record[0]);
1412      Value *Op = getFnValueByID(Record[1], OpTy);
1413      if (!OpTy || !Op)
1414        return Error("Invalid LOAD record");
1415      I = new LoadInst(Op, "", Record[3], (1 << Record[2]) >> 1);
1416      break;
1417    }
1418    case bitc::FUNC_CODE_INST_STORE: { // STORE:[ptrty,val,ptr, align, vol]
1419      if (Record.size() < 5)
1420        return Error("Invalid LOAD record");
1421      const PointerType *OpTy =
1422        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1423      Value *Op = getFnValueByID(Record[1], OpTy ? OpTy->getElementType() : 0);
1424      Value *Ptr = getFnValueByID(Record[2], OpTy);
1425      if (!OpTy || !Op || !Ptr)
1426        return Error("Invalid STORE record");
1427      I = new StoreInst(Op, Ptr, (1 << Record[3]) >> 1, Record[4]);
1428      break;
1429    }
1430    case bitc::FUNC_CODE_INST_CALL: { // CALL: [cc, fnty, fnid, arg0, arg1...]
1431      if (Record.size() < 3)
1432        return Error("Invalid CALL record");
1433      unsigned CCInfo = Record[0];
1434      const PointerType *OpTy =
1435        dyn_cast_or_null<PointerType>(getTypeByID(Record[1]));
1436      const FunctionType *FTy = 0;
1437      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1438      Value *Callee = getFnValueByID(Record[2], OpTy);
1439      if (!FTy || !Callee || Record.size() < FTy->getNumParams()+3)
1440        return Error("Invalid CALL record");
1441
1442      SmallVector<Value*, 16> Args;
1443      // Read the fixed params.
1444      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1445        Args.push_back(getFnValueByID(Record[i+3], FTy->getParamType(i)));
1446        if (Args.back() == 0) return Error("Invalid CALL record");
1447      }
1448
1449
1450      // Read type/value pairs for varargs params.
1451      unsigned NextArg = FTy->getNumParams()+3;
1452      if (!FTy->isVarArg()) {
1453        if (NextArg != Record.size())
1454          return Error("Invalid CALL record");
1455      } else {
1456        if ((Record.size()-NextArg) & 1)
1457          return Error("Invalid CALL record");
1458        for (unsigned e = Record.size(); NextArg != e; NextArg += 2) {
1459          Args.push_back(getFnValueByID(Record[NextArg+1],
1460                                        getTypeByID(Record[NextArg])));
1461          if (Args.back() == 0) return Error("Invalid CALL record");
1462        }
1463      }
1464
1465      I = new CallInst(Callee, &Args[0], Args.size());
1466      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1467      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1468      break;
1469    }
1470    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1471      if (Record.size() < 3)
1472        return Error("Invalid VAARG record");
1473      const Type *OpTy = getTypeByID(Record[0]);
1474      Value *Op = getFnValueByID(Record[1], OpTy);
1475      const Type *ResTy = getTypeByID(Record[2]);
1476      if (!OpTy || !Op || !ResTy)
1477        return Error("Invalid VAARG record");
1478      I = new VAArgInst(Op, ResTy);
1479      break;
1480    }
1481    }
1482
1483    // Add instruction to end of current BB.  If there is no current BB, reject
1484    // this file.
1485    if (CurBB == 0) {
1486      delete I;
1487      return Error("Invalid instruction with no BB");
1488    }
1489    CurBB->getInstList().push_back(I);
1490
1491    // If this was a terminator instruction, move to the next block.
1492    if (isa<TerminatorInst>(I)) {
1493      ++CurBBNo;
1494      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1495    }
1496
1497    // Non-void values get registered in the value table for future use.
1498    if (I && I->getType() != Type::VoidTy)
1499      ValueList.AssignValue(I, NextValueNo++);
1500  }
1501
1502  // Check the function list for unresolved values.
1503  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1504    if (A->getParent() == 0) {
1505      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1506      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1507        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1508          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1509          delete A;
1510        }
1511      }
1512    }
1513    return Error("Never resolved value found in function!");
1514  }
1515
1516  // Trim the value list down to the size it was before we parsed this function.
1517  ValueList.shrinkTo(ModuleValueListSize);
1518  std::vector<BasicBlock*>().swap(FunctionBBs);
1519
1520  return false;
1521}
1522
1523
1524//===----------------------------------------------------------------------===//
1525// External interface
1526//===----------------------------------------------------------------------===//
1527
1528/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1529///
1530ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1531                                               std::string *ErrMsg) {
1532  BitcodeReader *R = new BitcodeReader(Buffer);
1533  if (R->ParseBitcode()) {
1534    if (ErrMsg)
1535      *ErrMsg = R->getErrorString();
1536
1537    // Don't let the BitcodeReader dtor delete 'Buffer'.
1538    R->releaseMemoryBuffer();
1539    delete R;
1540    return 0;
1541  }
1542  return R;
1543}
1544
1545/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
1546/// If an error occurs, return null and fill in *ErrMsg if non-null.
1547Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
1548  BitcodeReader *R;
1549  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
1550  if (!R) return 0;
1551
1552  // Read the whole module, get a pointer to it, tell ModuleProvider not to
1553  // delete it when its dtor is run.
1554  Module *M = R->releaseModule(ErrMsg);
1555
1556  // Don't let the BitcodeReader dtor delete 'Buffer'.
1557  R->releaseMemoryBuffer();
1558  delete R;
1559  return M;
1560}
1561