BitcodeReader.cpp revision 15e6d170e8d4b99937d34aef2c02078247f4cdf7 
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 (Idx > Record.size())
40    return true;
41
42  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
43    Result += (char)Record[i];
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, attrid, retty, paramty x N]
317      if (Record.size() < 3)
318        return Error("Invalid FUNCTION type record");
319      std::vector<const Type*> ArgTys;
320      for (unsigned i = 3, e = Record.size(); i != e; ++i)
321        ArgTys.push_back(getTypeByID(Record[i], true));
322
323      ResultTy = FunctionType::get(getTypeByID(Record[2], true), ArgTys,
324                                   Record[0], getParamAttrs(Record[1]));
325      break;
326    }
327    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, eltty x N]
328      if (Record.size() < 2)
329        return Error("Invalid STRUCT type record");
330      std::vector<const Type*> EltTys;
331      for (unsigned i = 1, e = Record.size(); i != e; ++i)
332        EltTys.push_back(getTypeByID(Record[i], true));
333      ResultTy = StructType::get(EltTys, Record[0]);
334      break;
335    }
336    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
337      if (Record.size() < 2)
338        return Error("Invalid ARRAY type record");
339      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
340      break;
341    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
342      if (Record.size() < 2)
343        return Error("Invalid VECTOR type record");
344      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
345      break;
346    }
347
348    if (NumRecords == TypeList.size()) {
349      // If this is a new type slot, just append it.
350      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
351      ++NumRecords;
352    } else if (ResultTy == 0) {
353      // Otherwise, this was forward referenced, so an opaque type was created,
354      // but the result type is actually just an opaque.  Leave the one we
355      // created previously.
356      ++NumRecords;
357    } else {
358      // Otherwise, this was forward referenced, so an opaque type was created.
359      // Resolve the opaque type to the real type now.
360      assert(NumRecords < TypeList.size() && "Typelist imbalance");
361      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
362
363      // Don't directly push the new type on the Tab. Instead we want to replace
364      // the opaque type we previously inserted with the new concrete value. The
365      // refinement from the abstract (opaque) type to the new type causes all
366      // uses of the abstract type to use the concrete type (NewTy). This will
367      // also cause the opaque type to be deleted.
368      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
369
370      // This should have replaced the old opaque type with the new type in the
371      // value table... or with a preexisting type that was already in the
372      // system.  Let's just make sure it did.
373      assert(TypeList[NumRecords-1].get() != OldTy &&
374             "refineAbstractType didn't work!");
375    }
376  }
377}
378
379
380bool BitcodeReader::ParseTypeSymbolTable() {
381  if (Stream.EnterSubBlock())
382    return Error("Malformed block record");
383
384  SmallVector<uint64_t, 64> Record;
385
386  // Read all the records for this type table.
387  std::string TypeName;
388  while (1) {
389    unsigned Code = Stream.ReadCode();
390    if (Code == bitc::END_BLOCK) {
391      if (Stream.ReadBlockEnd())
392        return Error("Error at end of type symbol table block");
393      return false;
394    }
395
396    if (Code == bitc::ENTER_SUBBLOCK) {
397      // No known subblocks, always skip them.
398      Stream.ReadSubBlockID();
399      if (Stream.SkipBlock())
400        return Error("Malformed block record");
401      continue;
402    }
403
404    if (Code == bitc::DEFINE_ABBREV) {
405      Stream.ReadAbbrevRecord();
406      continue;
407    }
408
409    // Read a record.
410    Record.clear();
411    switch (Stream.ReadRecord(Code, Record)) {
412    default:  // Default behavior: unknown type.
413      break;
414    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namechar x N]
415      if (ConvertToString(Record, 1, TypeName))
416        return Error("Invalid TST_ENTRY record");
417      unsigned TypeID = Record[0];
418      if (TypeID >= TypeList.size())
419        return Error("Invalid Type ID in TST_ENTRY record");
420
421      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
422      TypeName.clear();
423      break;
424    }
425  }
426}
427
428bool BitcodeReader::ParseValueSymbolTable() {
429  if (Stream.EnterSubBlock())
430    return Error("Malformed block record");
431
432  SmallVector<uint64_t, 64> Record;
433
434  // Read all the records for this value table.
435  SmallString<128> ValueName;
436  while (1) {
437    unsigned Code = Stream.ReadCode();
438    if (Code == bitc::END_BLOCK) {
439      if (Stream.ReadBlockEnd())
440        return Error("Error at end of value symbol table block");
441      return false;
442    }
443    if (Code == bitc::ENTER_SUBBLOCK) {
444      // No known subblocks, always skip them.
445      Stream.ReadSubBlockID();
446      if (Stream.SkipBlock())
447        return Error("Malformed block record");
448      continue;
449    }
450
451    if (Code == bitc::DEFINE_ABBREV) {
452      Stream.ReadAbbrevRecord();
453      continue;
454    }
455
456    // Read a record.
457    Record.clear();
458    switch (Stream.ReadRecord(Code, Record)) {
459    default:  // Default behavior: unknown type.
460      break;
461    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
462      if (ConvertToString(Record, 1, ValueName))
463        return Error("Invalid TST_ENTRY record");
464      unsigned ValueID = Record[0];
465      if (ValueID >= ValueList.size())
466        return Error("Invalid Value ID in VST_ENTRY record");
467      Value *V = ValueList[ValueID];
468
469      V->setName(&ValueName[0], ValueName.size());
470      ValueName.clear();
471      break;
472    }
473    case bitc::VST_CODE_BBENTRY: {
474      if (ConvertToString(Record, 1, ValueName))
475        return Error("Invalid VST_BBENTRY record");
476      BasicBlock *BB = getBasicBlock(Record[0]);
477      if (BB == 0)
478        return Error("Invalid BB ID in VST_BBENTRY record");
479
480      BB->setName(&ValueName[0], ValueName.size());
481      ValueName.clear();
482      break;
483    }
484    }
485  }
486}
487
488/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
489/// the LSB for dense VBR encoding.
490static uint64_t DecodeSignRotatedValue(uint64_t V) {
491  if ((V & 1) == 0)
492    return V >> 1;
493  if (V != 1)
494    return -(V >> 1);
495  // There is no such thing as -0 with integers.  "-0" really means MININT.
496  return 1ULL << 63;
497}
498
499/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
500/// values and aliases that we can.
501bool BitcodeReader::ResolveGlobalAndAliasInits() {
502  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
503  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
504
505  GlobalInitWorklist.swap(GlobalInits);
506  AliasInitWorklist.swap(AliasInits);
507
508  while (!GlobalInitWorklist.empty()) {
509    unsigned ValID = GlobalInitWorklist.back().second;
510    if (ValID >= ValueList.size()) {
511      // Not ready to resolve this yet, it requires something later in the file.
512      GlobalInits.push_back(GlobalInitWorklist.back());
513    } else {
514      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
515        GlobalInitWorklist.back().first->setInitializer(C);
516      else
517        return Error("Global variable initializer is not a constant!");
518    }
519    GlobalInitWorklist.pop_back();
520  }
521
522  while (!AliasInitWorklist.empty()) {
523    unsigned ValID = AliasInitWorklist.back().second;
524    if (ValID >= ValueList.size()) {
525      AliasInits.push_back(AliasInitWorklist.back());
526    } else {
527      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
528        AliasInitWorklist.back().first->setAliasee(C);
529      else
530        return Error("Alias initializer is not a constant!");
531    }
532    AliasInitWorklist.pop_back();
533  }
534  return false;
535}
536
537
538bool BitcodeReader::ParseConstants() {
539  if (Stream.EnterSubBlock())
540    return Error("Malformed block record");
541
542  SmallVector<uint64_t, 64> Record;
543
544  // Read all the records for this value table.
545  const Type *CurTy = Type::Int32Ty;
546  unsigned NextCstNo = ValueList.size();
547  while (1) {
548    unsigned Code = Stream.ReadCode();
549    if (Code == bitc::END_BLOCK) {
550      if (NextCstNo != ValueList.size())
551        return Error("Invalid constant reference!");
552
553      if (Stream.ReadBlockEnd())
554        return Error("Error at end of constants block");
555      return false;
556    }
557
558    if (Code == bitc::ENTER_SUBBLOCK) {
559      // No known subblocks, always skip them.
560      Stream.ReadSubBlockID();
561      if (Stream.SkipBlock())
562        return Error("Malformed block record");
563      continue;
564    }
565
566    if (Code == bitc::DEFINE_ABBREV) {
567      Stream.ReadAbbrevRecord();
568      continue;
569    }
570
571    // Read a record.
572    Record.clear();
573    Value *V = 0;
574    switch (Stream.ReadRecord(Code, Record)) {
575    default:  // Default behavior: unknown constant
576    case bitc::CST_CODE_UNDEF:     // UNDEF
577      V = UndefValue::get(CurTy);
578      break;
579    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
580      if (Record.empty())
581        return Error("Malformed CST_SETTYPE record");
582      if (Record[0] >= TypeList.size())
583        return Error("Invalid Type ID in CST_SETTYPE record");
584      CurTy = TypeList[Record[0]];
585      continue;  // Skip the ValueList manipulation.
586    case bitc::CST_CODE_NULL:      // NULL
587      V = Constant::getNullValue(CurTy);
588      break;
589    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
590      if (!isa<IntegerType>(CurTy) || Record.empty())
591        return Error("Invalid CST_INTEGER record");
592      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
593      break;
594    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
595      if (!isa<IntegerType>(CurTy) || Record.empty())
596        return Error("Invalid WIDE_INTEGER record");
597
598      unsigned NumWords = Record.size();
599      SmallVector<uint64_t, 8> Words;
600      Words.resize(NumWords);
601      for (unsigned i = 0; i != NumWords; ++i)
602        Words[i] = DecodeSignRotatedValue(Record[i]);
603      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
604                                 NumWords, &Words[0]));
605      break;
606    }
607    case bitc::CST_CODE_FLOAT:     // FLOAT: [fpval]
608      if (Record.empty())
609        return Error("Invalid FLOAT record");
610      if (CurTy == Type::FloatTy)
611        V = ConstantFP::get(CurTy, BitsToFloat(Record[0]));
612      else if (CurTy == Type::DoubleTy)
613        V = ConstantFP::get(CurTy, BitsToDouble(Record[0]));
614      else
615        V = UndefValue::get(CurTy);
616      break;
617
618    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
619      if (Record.empty())
620        return Error("Invalid CST_AGGREGATE record");
621
622      unsigned Size = Record.size();
623      std::vector<Constant*> Elts;
624
625      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
626        for (unsigned i = 0; i != Size; ++i)
627          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
628                                                     STy->getElementType(i)));
629        V = ConstantStruct::get(STy, Elts);
630      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
631        const Type *EltTy = ATy->getElementType();
632        for (unsigned i = 0; i != Size; ++i)
633          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
634        V = ConstantArray::get(ATy, Elts);
635      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
636        const Type *EltTy = VTy->getElementType();
637        for (unsigned i = 0; i != Size; ++i)
638          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
639        V = ConstantVector::get(Elts);
640      } else {
641        V = UndefValue::get(CurTy);
642      }
643      break;
644    }
645
646    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
647      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
648      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
649      if (Opc < 0) {
650        V = UndefValue::get(CurTy);  // Unknown binop.
651      } else {
652        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
653        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
654        V = ConstantExpr::get(Opc, LHS, RHS);
655      }
656      break;
657    }
658    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
659      if (Record.size() < 3) return Error("Invalid CE_CAST record");
660      int Opc = GetDecodedCastOpcode(Record[0]);
661      if (Opc < 0) {
662        V = UndefValue::get(CurTy);  // Unknown cast.
663      } else {
664        const Type *OpTy = getTypeByID(Record[1]);
665        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
666        V = ConstantExpr::getCast(Opc, Op, CurTy);
667      }
668      break;
669    }
670    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
671      if (Record.size() & 1) return Error("Invalid CE_GEP record");
672      SmallVector<Constant*, 16> Elts;
673      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
674        const Type *ElTy = getTypeByID(Record[i]);
675        if (!ElTy) return Error("Invalid CE_GEP record");
676        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
677      }
678      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
679      break;
680    }
681    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
682      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
683      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
684                                                              Type::Int1Ty),
685                                  ValueList.getConstantFwdRef(Record[1],CurTy),
686                                  ValueList.getConstantFwdRef(Record[2],CurTy));
687      break;
688    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
689      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
690      const VectorType *OpTy =
691        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
692      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
693      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
694      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
695                                                  OpTy->getElementType());
696      V = ConstantExpr::getExtractElement(Op0, Op1);
697      break;
698    }
699    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
700      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
701      if (Record.size() < 3 || OpTy == 0)
702        return Error("Invalid CE_INSERTELT record");
703      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
704      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
705                                                  OpTy->getElementType());
706      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
707      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
708      break;
709    }
710    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
711      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
712      if (Record.size() < 3 || OpTy == 0)
713        return Error("Invalid CE_INSERTELT record");
714      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
715      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
716      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
717      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
718      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
719      break;
720    }
721    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
722      if (Record.size() < 4) return Error("Invalid CE_CMP record");
723      const Type *OpTy = getTypeByID(Record[0]);
724      if (OpTy == 0) return Error("Invalid CE_CMP record");
725      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
726      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
727
728      if (OpTy->isFloatingPoint())
729        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
730      else
731        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
732      break;
733    }
734    }
735
736    ValueList.AssignValue(V, NextCstNo);
737    ++NextCstNo;
738  }
739}
740
741/// RememberAndSkipFunctionBody - When we see the block for a function body,
742/// remember where it is and then skip it.  This lets us lazily deserialize the
743/// functions.
744bool BitcodeReader::RememberAndSkipFunctionBody() {
745  // Get the function we are talking about.
746  if (FunctionsWithBodies.empty())
747    return Error("Insufficient function protos");
748
749  Function *Fn = FunctionsWithBodies.back();
750  FunctionsWithBodies.pop_back();
751
752  // Save the current stream state.
753  uint64_t CurBit = Stream.GetCurrentBitNo();
754  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
755
756  // Set the functions linkage to GhostLinkage so we know it is lazily
757  // deserialized.
758  Fn->setLinkage(GlobalValue::GhostLinkage);
759
760  // Skip over the function block for now.
761  if (Stream.SkipBlock())
762    return Error("Malformed block record");
763  return false;
764}
765
766bool BitcodeReader::ParseModule(const std::string &ModuleID) {
767  // Reject multiple MODULE_BLOCK's in a single bitstream.
768  if (TheModule)
769    return Error("Multiple MODULE_BLOCKs in same stream");
770
771  if (Stream.EnterSubBlock())
772    return Error("Malformed block record");
773
774  // Otherwise, create the module.
775  TheModule = new Module(ModuleID);
776
777  SmallVector<uint64_t, 64> Record;
778  std::vector<std::string> SectionTable;
779
780  // Read all the records for this module.
781  while (!Stream.AtEndOfStream()) {
782    unsigned Code = Stream.ReadCode();
783    if (Code == bitc::END_BLOCK) {
784      if (Stream.ReadBlockEnd())
785        return Error("Error at end of module block");
786
787      // Patch the initializers for globals and aliases up.
788      ResolveGlobalAndAliasInits();
789      if (!GlobalInits.empty() || !AliasInits.empty())
790        return Error("Malformed global initializer set");
791      if (!FunctionsWithBodies.empty())
792        return Error("Too few function bodies found");
793
794      // Force deallocation of memory for these vectors to favor the client that
795      // want lazy deserialization.
796      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
797      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
798      std::vector<Function*>().swap(FunctionsWithBodies);
799      return false;
800    }
801
802    if (Code == bitc::ENTER_SUBBLOCK) {
803      switch (Stream.ReadSubBlockID()) {
804      default:  // Skip unknown content.
805        if (Stream.SkipBlock())
806          return Error("Malformed block record");
807        break;
808      case bitc::PARAMATTR_BLOCK_ID:
809        if (ParseParamAttrBlock())
810          return true;
811        break;
812      case bitc::TYPE_BLOCK_ID:
813        if (ParseTypeTable())
814          return true;
815        break;
816      case bitc::TYPE_SYMTAB_BLOCK_ID:
817        if (ParseTypeSymbolTable())
818          return true;
819        break;
820      case bitc::VALUE_SYMTAB_BLOCK_ID:
821        if (ParseValueSymbolTable())
822          return true;
823        break;
824      case bitc::CONSTANTS_BLOCK_ID:
825        if (ParseConstants() || ResolveGlobalAndAliasInits())
826          return true;
827        break;
828      case bitc::FUNCTION_BLOCK_ID:
829        // If this is the first function body we've seen, reverse the
830        // FunctionsWithBodies list.
831        if (!HasReversedFunctionsWithBodies) {
832          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
833          HasReversedFunctionsWithBodies = true;
834        }
835
836        if (RememberAndSkipFunctionBody())
837          return true;
838        break;
839      }
840      continue;
841    }
842
843    if (Code == bitc::DEFINE_ABBREV) {
844      Stream.ReadAbbrevRecord();
845      continue;
846    }
847
848    // Read a record.
849    switch (Stream.ReadRecord(Code, Record)) {
850    default: break;  // Default behavior, ignore unknown content.
851    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
852      if (Record.size() < 1)
853        return Error("Malformed MODULE_CODE_VERSION");
854      // Only version #0 is supported so far.
855      if (Record[0] != 0)
856        return Error("Unknown bitstream version!");
857      break;
858    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
859      std::string S;
860      if (ConvertToString(Record, 0, S))
861        return Error("Invalid MODULE_CODE_TRIPLE record");
862      TheModule->setTargetTriple(S);
863      break;
864    }
865    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
866      std::string S;
867      if (ConvertToString(Record, 0, S))
868        return Error("Invalid MODULE_CODE_DATALAYOUT record");
869      TheModule->setDataLayout(S);
870      break;
871    }
872    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
873      std::string S;
874      if (ConvertToString(Record, 0, S))
875        return Error("Invalid MODULE_CODE_ASM record");
876      TheModule->setModuleInlineAsm(S);
877      break;
878    }
879    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
880      std::string S;
881      if (ConvertToString(Record, 0, S))
882        return Error("Invalid MODULE_CODE_DEPLIB record");
883      TheModule->addLibrary(S);
884      break;
885    }
886    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
887      std::string S;
888      if (ConvertToString(Record, 0, S))
889        return Error("Invalid MODULE_CODE_SECTIONNAME record");
890      SectionTable.push_back(S);
891      break;
892    }
893    // GLOBALVAR: [type, isconst, initid,
894    //             linkage, alignment, section, visibility, threadlocal]
895    case bitc::MODULE_CODE_GLOBALVAR: {
896      if (Record.size() < 6)
897        return Error("Invalid MODULE_CODE_GLOBALVAR record");
898      const Type *Ty = getTypeByID(Record[0]);
899      if (!isa<PointerType>(Ty))
900        return Error("Global not a pointer type!");
901      Ty = cast<PointerType>(Ty)->getElementType();
902
903      bool isConstant = Record[1];
904      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
905      unsigned Alignment = (1 << Record[4]) >> 1;
906      std::string Section;
907      if (Record[5]) {
908        if (Record[5]-1 >= SectionTable.size())
909          return Error("Invalid section ID");
910        Section = SectionTable[Record[5]-1];
911      }
912      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
913      if (Record.size() >= 6) Visibility = GetDecodedVisibility(Record[6]);
914      bool isThreadLocal = false;
915      if (Record.size() >= 7) isThreadLocal = Record[7];
916
917      GlobalVariable *NewGV =
918        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule);
919      NewGV->setAlignment(Alignment);
920      if (!Section.empty())
921        NewGV->setSection(Section);
922      NewGV->setVisibility(Visibility);
923      NewGV->setThreadLocal(isThreadLocal);
924
925      ValueList.push_back(NewGV);
926
927      // Remember which value to use for the global initializer.
928      if (unsigned InitID = Record[2])
929        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
930      break;
931    }
932    // FUNCTION:  [type, callingconv, isproto, linkage, alignment, section,
933    //             visibility]
934    case bitc::MODULE_CODE_FUNCTION: {
935      if (Record.size() < 7)
936        return Error("Invalid MODULE_CODE_FUNCTION record");
937      const Type *Ty = getTypeByID(Record[0]);
938      if (!isa<PointerType>(Ty))
939        return Error("Function not a pointer type!");
940      const FunctionType *FTy =
941        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
942      if (!FTy)
943        return Error("Function not a pointer to function type!");
944
945      Function *Func = new Function(FTy, GlobalValue::ExternalLinkage,
946                                    "", TheModule);
947
948      Func->setCallingConv(Record[1]);
949      bool isProto = Record[2];
950      Func->setLinkage(GetDecodedLinkage(Record[3]));
951      Func->setAlignment((1 << Record[4]) >> 1);
952      if (Record[5]) {
953        if (Record[5]-1 >= SectionTable.size())
954          return Error("Invalid section ID");
955        Func->setSection(SectionTable[Record[5]-1]);
956      }
957      Func->setVisibility(GetDecodedVisibility(Record[6]));
958
959      ValueList.push_back(Func);
960
961      // If this is a function with a body, remember the prototype we are
962      // creating now, so that we can match up the body with them later.
963      if (!isProto)
964        FunctionsWithBodies.push_back(Func);
965      break;
966    }
967    // ALIAS: [alias type, aliasee val#, linkage]
968    case bitc::MODULE_CODE_ALIAS: {
969      if (Record.size() < 3)
970        return Error("Invalid MODULE_ALIAS record");
971      const Type *Ty = getTypeByID(Record[0]);
972      if (!isa<PointerType>(Ty))
973        return Error("Function not a pointer type!");
974
975      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
976                                           "", 0, TheModule);
977      ValueList.push_back(NewGA);
978      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
979      break;
980    }
981    /// MODULE_CODE_PURGEVALS: [numvals]
982    case bitc::MODULE_CODE_PURGEVALS:
983      // Trim down the value list to the specified size.
984      if (Record.size() < 1 || Record[0] > ValueList.size())
985        return Error("Invalid MODULE_PURGEVALS record");
986      ValueList.shrinkTo(Record[0]);
987      break;
988    }
989    Record.clear();
990  }
991
992  return Error("Premature end of bitstream");
993}
994
995
996bool BitcodeReader::ParseBitcode() {
997  TheModule = 0;
998
999  if (Buffer->getBufferSize() & 3)
1000    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1001
1002  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1003  Stream.init(BufPtr, BufPtr+Buffer->getBufferSize());
1004
1005  // Sniff for the signature.
1006  if (Stream.Read(8) != 'B' ||
1007      Stream.Read(8) != 'C' ||
1008      Stream.Read(4) != 0x0 ||
1009      Stream.Read(4) != 0xC ||
1010      Stream.Read(4) != 0xE ||
1011      Stream.Read(4) != 0xD)
1012    return Error("Invalid bitcode signature");
1013
1014  // We expect a number of well-defined blocks, though we don't necessarily
1015  // need to understand them all.
1016  while (!Stream.AtEndOfStream()) {
1017    unsigned Code = Stream.ReadCode();
1018
1019    if (Code != bitc::ENTER_SUBBLOCK)
1020      return Error("Invalid record at top-level");
1021
1022    unsigned BlockID = Stream.ReadSubBlockID();
1023
1024    // We only know the MODULE subblock ID.
1025    if (BlockID == bitc::MODULE_BLOCK_ID) {
1026      if (ParseModule(Buffer->getBufferIdentifier()))
1027        return true;
1028    } else if (Stream.SkipBlock()) {
1029      return Error("Malformed block record");
1030    }
1031  }
1032
1033  return false;
1034}
1035
1036
1037bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1038  // If it already is material, ignore the request.
1039  if (!F->hasNotBeenReadFromBytecode()) return false;
1040
1041  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1042    DeferredFunctionInfo.find(F);
1043  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1044
1045  // Move the bit stream to the saved position of the deferred function body and
1046  // restore the real linkage type for the function.
1047  Stream.JumpToBit(DFII->second.first);
1048  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1049  DeferredFunctionInfo.erase(DFII);
1050
1051  if (ParseFunctionBody(F)) {
1052    if (ErrInfo) *ErrInfo = ErrorString;
1053    return true;
1054  }
1055
1056  return false;
1057}
1058
1059Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
1060  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1061    DeferredFunctionInfo.begin();
1062  while (!DeferredFunctionInfo.empty()) {
1063    Function *F = (*I++).first;
1064    assert(F->hasNotBeenReadFromBytecode() &&
1065           "Deserialized function found in map!");
1066    if (materializeFunction(F, ErrInfo))
1067      return 0;
1068  }
1069  return TheModule;
1070}
1071
1072
1073/// ParseFunctionBody - Lazily parse the specified function body block.
1074bool BitcodeReader::ParseFunctionBody(Function *F) {
1075  if (Stream.EnterSubBlock())
1076    return Error("Malformed block record");
1077
1078  unsigned ModuleValueListSize = ValueList.size();
1079
1080  // Add all the function arguments to the value table.
1081  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1082    ValueList.push_back(I);
1083
1084  unsigned NextValueNo = ValueList.size();
1085  BasicBlock *CurBB = 0;
1086  unsigned CurBBNo = 0;
1087
1088  // Read all the records.
1089  SmallVector<uint64_t, 64> Record;
1090  while (1) {
1091    unsigned Code = Stream.ReadCode();
1092    if (Code == bitc::END_BLOCK) {
1093      if (Stream.ReadBlockEnd())
1094        return Error("Error at end of function block");
1095      break;
1096    }
1097
1098    if (Code == bitc::ENTER_SUBBLOCK) {
1099      switch (Stream.ReadSubBlockID()) {
1100      default:  // Skip unknown content.
1101        if (Stream.SkipBlock())
1102          return Error("Malformed block record");
1103        break;
1104      case bitc::CONSTANTS_BLOCK_ID:
1105        if (ParseConstants()) return true;
1106        NextValueNo = ValueList.size();
1107        break;
1108      case bitc::VALUE_SYMTAB_BLOCK_ID:
1109        if (ParseValueSymbolTable()) return true;
1110        break;
1111      }
1112      continue;
1113    }
1114
1115    if (Code == bitc::DEFINE_ABBREV) {
1116      Stream.ReadAbbrevRecord();
1117      continue;
1118    }
1119
1120    // Read a record.
1121    Record.clear();
1122    Instruction *I = 0;
1123    switch (Stream.ReadRecord(Code, Record)) {
1124    default: // Default behavior: reject
1125      return Error("Unknown instruction");
1126    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1127      if (Record.size() < 1 || Record[0] == 0)
1128        return Error("Invalid DECLAREBLOCKS record");
1129      // Create all the basic blocks for the function.
1130      FunctionBBs.resize(Record[0]);
1131      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1132        FunctionBBs[i] = new BasicBlock("", F);
1133      CurBB = FunctionBBs[0];
1134      continue;
1135
1136    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opcode, ty, opval, opval]
1137      if (Record.size() < 4) return Error("Invalid BINOP record");
1138      const Type *Ty = getTypeByID(Record[1]);
1139      int Opc = GetDecodedBinaryOpcode(Record[0], Ty);
1140      Value *LHS = getFnValueByID(Record[2], Ty);
1141      Value *RHS = getFnValueByID(Record[3], Ty);
1142      if (Opc == -1 || Ty == 0 || LHS == 0 || RHS == 0)
1143         return Error("Invalid BINOP record");
1144      I = BinaryOperator::create((Instruction::BinaryOps)Opc, LHS, RHS);
1145      break;
1146    }
1147    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opcode, ty, opty, opval]
1148      if (Record.size() < 4) return Error("Invalid CAST record");
1149      int Opc = GetDecodedCastOpcode(Record[0]);
1150      const Type *ResTy = getTypeByID(Record[1]);
1151      const Type *OpTy = getTypeByID(Record[2]);
1152      Value *Op = getFnValueByID(Record[3], OpTy);
1153      if (Opc == -1 || ResTy == 0 || OpTy == 0 || Op == 0)
1154        return Error("Invalid CAST record");
1155      I = CastInst::create((Instruction::CastOps)Opc, Op, ResTy);
1156      break;
1157    }
1158    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
1159      if (Record.size() < 2 || (Record.size() & 1))
1160        return Error("Invalid GEP record");
1161      const Type *OpTy = getTypeByID(Record[0]);
1162      Value *Op = getFnValueByID(Record[1], OpTy);
1163      if (OpTy == 0 || Op == 0)
1164        return Error("Invalid GEP record");
1165
1166      SmallVector<Value*, 16> GEPIdx;
1167      for (unsigned i = 1, e = Record.size()/2; i != e; ++i) {
1168        const Type *IdxTy = getTypeByID(Record[i*2]);
1169        Value *Idx = getFnValueByID(Record[i*2+1], IdxTy);
1170        if (IdxTy == 0 || Idx == 0)
1171          return Error("Invalid GEP record");
1172        GEPIdx.push_back(Idx);
1173      }
1174
1175      I = new GetElementPtrInst(Op, &GEPIdx[0], GEPIdx.size());
1176      break;
1177    }
1178
1179    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [ty, opval, opval, opval]
1180      if (Record.size() < 4) return Error("Invalid SELECT record");
1181      const Type *Ty = getTypeByID(Record[0]);
1182      Value *Cond = getFnValueByID(Record[1], Type::Int1Ty);
1183      Value *LHS = getFnValueByID(Record[2], Ty);
1184      Value *RHS = getFnValueByID(Record[3], Ty);
1185      if (Ty == 0 || Cond == 0 || LHS == 0 || RHS == 0)
1186        return Error("Invalid SELECT record");
1187      I = new SelectInst(Cond, LHS, RHS);
1188      break;
1189    }
1190
1191    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1192      if (Record.size() < 3) return Error("Invalid EXTRACTELT record");
1193      const Type *OpTy = getTypeByID(Record[0]);
1194      Value *Vec = getFnValueByID(Record[1], OpTy);
1195      Value *Idx = getFnValueByID(Record[2], Type::Int32Ty);
1196      if (OpTy == 0 || Vec == 0 || Idx == 0)
1197        return Error("Invalid EXTRACTELT record");
1198      I = new ExtractElementInst(Vec, Idx);
1199      break;
1200    }
1201
1202    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1203      if (Record.size() < 4) return Error("Invalid INSERTELT record");
1204      const VectorType *OpTy =
1205        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1206      if (OpTy == 0) return Error("Invalid INSERTELT record");
1207      Value *Vec = getFnValueByID(Record[1], OpTy);
1208      Value *Elt = getFnValueByID(Record[2], OpTy->getElementType());
1209      Value *Idx = getFnValueByID(Record[3], Type::Int32Ty);
1210      if (Vec == 0 || Elt == 0 || Idx == 0)
1211        return Error("Invalid INSERTELT record");
1212      I = new InsertElementInst(Vec, Elt, Idx);
1213      break;
1214    }
1215
1216    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [ty,opval,opval,opval]
1217      if (Record.size() < 4) return Error("Invalid SHUFFLEVEC record");
1218      const VectorType *OpTy =
1219        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1220      if (OpTy == 0) return Error("Invalid SHUFFLEVEC record");
1221      Value *Vec1 = getFnValueByID(Record[1], OpTy);
1222      Value *Vec2 = getFnValueByID(Record[2], OpTy);
1223      Value *Mask = getFnValueByID(Record[3],
1224                                   VectorType::get(Type::Int32Ty,
1225                                                   OpTy->getNumElements()));
1226      if (Vec1 == 0 || Vec2 == 0 || Mask == 0)
1227        return Error("Invalid SHUFFLEVEC record");
1228      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1229      break;
1230    }
1231
1232    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1233      if (Record.size() < 4) return Error("Invalid CMP record");
1234      const Type *OpTy = getTypeByID(Record[0]);
1235      Value *LHS = getFnValueByID(Record[1], OpTy);
1236      Value *RHS = getFnValueByID(Record[2], OpTy);
1237      if (OpTy == 0 || LHS == 0 || RHS == 0)
1238        return Error("Invalid CMP record");
1239      if (OpTy->isFPOrFPVector())
1240        I = new FCmpInst((FCmpInst::Predicate)Record[3], LHS, RHS);
1241      else
1242        I = new ICmpInst((ICmpInst::Predicate)Record[3], LHS, RHS);
1243      break;
1244    }
1245
1246    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1247      if (Record.size() == 0) {
1248        I = new ReturnInst();
1249        break;
1250      }
1251      if (Record.size() == 2) {
1252        const Type *OpTy = getTypeByID(Record[0]);
1253        Value *Op = getFnValueByID(Record[1], OpTy);
1254        if (!OpTy || !Op)
1255          return Error("Invalid RET record");
1256        I = new ReturnInst(Op);
1257        break;
1258      }
1259      return Error("Invalid RET record");
1260    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1261      if (Record.size() != 1 && Record.size() != 3)
1262        return Error("Invalid BR record");
1263      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1264      if (TrueDest == 0)
1265        return Error("Invalid BR record");
1266
1267      if (Record.size() == 1)
1268        I = new BranchInst(TrueDest);
1269      else {
1270        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1271        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1272        if (FalseDest == 0 || Cond == 0)
1273          return Error("Invalid BR record");
1274        I = new BranchInst(TrueDest, FalseDest, Cond);
1275      }
1276      break;
1277    }
1278    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1279      if (Record.size() < 3 || (Record.size() & 1) == 0)
1280        return Error("Invalid SWITCH record");
1281      const Type *OpTy = getTypeByID(Record[0]);
1282      Value *Cond = getFnValueByID(Record[1], OpTy);
1283      BasicBlock *Default = getBasicBlock(Record[2]);
1284      if (OpTy == 0 || Cond == 0 || Default == 0)
1285        return Error("Invalid SWITCH record");
1286      unsigned NumCases = (Record.size()-3)/2;
1287      SwitchInst *SI = new SwitchInst(Cond, Default, NumCases);
1288      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1289        ConstantInt *CaseVal =
1290          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1291        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1292        if (CaseVal == 0 || DestBB == 0) {
1293          delete SI;
1294          return Error("Invalid SWITCH record!");
1295        }
1296        SI->addCase(CaseVal, DestBB);
1297      }
1298      I = SI;
1299      break;
1300    }
1301
1302    case bitc::FUNC_CODE_INST_INVOKE: { // INVOKE: [cc,fnty, op0,op1,op2, ...]
1303      if (Record.size() < 5)
1304        return Error("Invalid INVOKE record");
1305      unsigned CCInfo = Record[0];
1306      const PointerType *CalleeTy =
1307        dyn_cast_or_null<PointerType>(getTypeByID(Record[1]));
1308      Value *Callee = getFnValueByID(Record[2], CalleeTy);
1309      BasicBlock *NormalBB = getBasicBlock(Record[3]);
1310      BasicBlock *UnwindBB = getBasicBlock(Record[4]);
1311      if (CalleeTy == 0 || Callee == 0 || NormalBB == 0 || UnwindBB == 0)
1312        return Error("Invalid INVOKE record");
1313
1314      const FunctionType *FTy =
1315        dyn_cast<FunctionType>(CalleeTy->getElementType());
1316
1317      // Check that the right number of fixed parameters are here.
1318      if (FTy == 0 || Record.size() < 5+FTy->getNumParams())
1319        return Error("Invalid INVOKE record");
1320
1321      SmallVector<Value*, 16> Ops;
1322      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1323        Ops.push_back(getFnValueByID(Record[5+i], FTy->getParamType(i)));
1324        if (Ops.back() == 0)
1325          return Error("Invalid INVOKE record");
1326      }
1327
1328      unsigned FirstVarargParam = 5+FTy->getNumParams();
1329      if (FTy->isVarArg()) {
1330        // Read type/value pairs for varargs params.
1331        if ((Record.size()-FirstVarargParam) & 1)
1332          return Error("Invalid INVOKE record");
1333
1334        for (unsigned i = FirstVarargParam, e = Record.size(); i != e; i += 2) {
1335          const Type *ArgTy = getTypeByID(Record[i]);
1336          Ops.push_back(getFnValueByID(Record[i+1], ArgTy));
1337          if (Ops.back() == 0 || ArgTy == 0)
1338            return Error("Invalid INVOKE record");
1339        }
1340      } else {
1341        if (Record.size() != FirstVarargParam)
1342          return Error("Invalid INVOKE record");
1343      }
1344
1345      I = new InvokeInst(Callee, NormalBB, UnwindBB, &Ops[0], Ops.size());
1346      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1347      break;
1348    }
1349    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1350      I = new UnwindInst();
1351      break;
1352    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1353      I = new UnreachableInst();
1354      break;
1355    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, #ops, val0,bb0, ...]
1356      if (Record.size() < 1 || ((Record.size()-1)&1))
1357        return Error("Invalid PHI record");
1358      const Type *Ty = getTypeByID(Record[0]);
1359      if (!Ty) return Error("Invalid PHI record");
1360
1361      PHINode *PN = new PHINode(Ty);
1362      PN->reserveOperandSpace(Record.size()-1);
1363
1364      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
1365        Value *V = getFnValueByID(Record[1+i], Ty);
1366        BasicBlock *BB = getBasicBlock(Record[2+i]);
1367        if (!V || !BB) return Error("Invalid PHI record");
1368        PN->addIncoming(V, BB);
1369      }
1370      I = PN;
1371      break;
1372    }
1373
1374    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1375      if (Record.size() < 3)
1376        return Error("Invalid MALLOC record");
1377      const PointerType *Ty =
1378        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1379      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1380      unsigned Align = Record[2];
1381      if (!Ty || !Size) return Error("Invalid MALLOC record");
1382      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1383      break;
1384    }
1385    case bitc::FUNC_CODE_INST_FREE: { // FREE: [opty, op]
1386      if (Record.size() < 2)
1387        return Error("Invalid FREE record");
1388      const Type *OpTy = getTypeByID(Record[0]);
1389      Value *Op = getFnValueByID(Record[1], OpTy);
1390      if (!OpTy || !Op)
1391        return Error("Invalid FREE record");
1392      I = new FreeInst(Op);
1393      break;
1394    }
1395    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1396      if (Record.size() < 3)
1397        return Error("Invalid ALLOCA record");
1398      const PointerType *Ty =
1399        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1400      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1401      unsigned Align = Record[2];
1402      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1403      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1404      break;
1405    }
1406    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1407      if (Record.size() < 4)
1408        return Error("Invalid LOAD record");
1409      const Type *OpTy = getTypeByID(Record[0]);
1410      Value *Op = getFnValueByID(Record[1], OpTy);
1411      if (!OpTy || !Op)
1412        return Error("Invalid LOAD record");
1413      I = new LoadInst(Op, "", Record[3], (1 << Record[2]) >> 1);
1414      break;
1415    }
1416    case bitc::FUNC_CODE_INST_STORE: { // STORE:[ptrty,val,ptr, align, vol]
1417      if (Record.size() < 5)
1418        return Error("Invalid LOAD record");
1419      const PointerType *OpTy =
1420        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1421      Value *Op = getFnValueByID(Record[1], OpTy ? OpTy->getElementType() : 0);
1422      Value *Ptr = getFnValueByID(Record[2], OpTy);
1423      if (!OpTy || !Op || !Ptr)
1424        return Error("Invalid STORE record");
1425      I = new StoreInst(Op, Ptr, Record[4], (1 << Record[3]) >> 1);
1426      break;
1427    }
1428    case bitc::FUNC_CODE_INST_CALL: { // CALL: [cc, fnty, fnid, arg0, arg1...]
1429      if (Record.size() < 3)
1430        return Error("Invalid CALL record");
1431      unsigned CCInfo = Record[0];
1432      const PointerType *OpTy =
1433        dyn_cast_or_null<PointerType>(getTypeByID(Record[1]));
1434      const FunctionType *FTy = 0;
1435      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1436      Value *Callee = getFnValueByID(Record[2], OpTy);
1437      if (!FTy || !Callee || Record.size() < FTy->getNumParams()+3)
1438        return Error("Invalid CALL record");
1439
1440      SmallVector<Value*, 16> Args;
1441      // Read the fixed params.
1442      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1443        Args.push_back(getFnValueByID(Record[i+3], FTy->getParamType(i)));
1444        if (Args.back() == 0) return Error("Invalid CALL record");
1445      }
1446
1447
1448      // Read type/value pairs for varargs params.
1449      unsigned NextArg = FTy->getNumParams()+3;
1450      if (!FTy->isVarArg()) {
1451        if (NextArg != Record.size())
1452          return Error("Invalid CALL record");
1453      } else {
1454        if ((Record.size()-NextArg) & 1)
1455          return Error("Invalid CALL record");
1456        for (unsigned e = Record.size(); NextArg != e; NextArg += 2) {
1457          Args.push_back(getFnValueByID(Record[NextArg+1],
1458                                        getTypeByID(Record[NextArg])));
1459          if (Args.back() == 0) return Error("Invalid CALL record");
1460        }
1461      }
1462
1463      I = new CallInst(Callee, &Args[0], Args.size());
1464      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1465      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1466      break;
1467    }
1468    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1469      if (Record.size() < 3)
1470        return Error("Invalid VAARG record");
1471      const Type *OpTy = getTypeByID(Record[0]);
1472      Value *Op = getFnValueByID(Record[1], OpTy);
1473      const Type *ResTy = getTypeByID(Record[2]);
1474      if (!OpTy || !Op || !ResTy)
1475        return Error("Invalid VAARG record");
1476      I = new VAArgInst(Op, ResTy);
1477      break;
1478    }
1479    }
1480
1481    // Add instruction to end of current BB.  If there is no current BB, reject
1482    // this file.
1483    if (CurBB == 0) {
1484      delete I;
1485      return Error("Invalid instruction with no BB");
1486    }
1487    CurBB->getInstList().push_back(I);
1488
1489    // If this was a terminator instruction, move to the next block.
1490    if (isa<TerminatorInst>(I)) {
1491      ++CurBBNo;
1492      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1493    }
1494
1495    // Non-void values get registered in the value table for future use.
1496    if (I && I->getType() != Type::VoidTy)
1497      ValueList.AssignValue(I, NextValueNo++);
1498  }
1499
1500  // Check the function list for unresolved values.
1501  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1502    if (A->getParent() == 0) {
1503      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1504      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1505        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1506          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1507          delete A;
1508        }
1509      }
1510      return Error("Never resolved value found in function!");
1511    }
1512  }
1513
1514  // Trim the value list down to the size it was before we parsed this function.
1515  ValueList.shrinkTo(ModuleValueListSize);
1516  std::vector<BasicBlock*>().swap(FunctionBBs);
1517
1518  return false;
1519}
1520
1521
1522//===----------------------------------------------------------------------===//
1523// External interface
1524//===----------------------------------------------------------------------===//
1525
1526/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1527///
1528ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1529                                               std::string *ErrMsg) {
1530  BitcodeReader *R = new BitcodeReader(Buffer);
1531  if (R->ParseBitcode()) {
1532    if (ErrMsg)
1533      *ErrMsg = R->getErrorString();
1534
1535    // Don't let the BitcodeReader dtor delete 'Buffer'.
1536    R->releaseMemoryBuffer();
1537    delete R;
1538    return 0;
1539  }
1540  return R;
1541}
1542
1543/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
1544/// If an error occurs, return null and fill in *ErrMsg if non-null.
1545Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
1546  BitcodeReader *R;
1547  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
1548  if (!R) return 0;
1549
1550  // Read the whole module, get a pointer to it, tell ModuleProvider not to
1551  // delete it when its dtor is run.
1552  Module *M = R->releaseModule(ErrMsg);
1553
1554  // Don't let the BitcodeReader dtor delete 'Buffer'.
1555  R->releaseMemoryBuffer();
1556  delete R;
1557  return M;
1558}
1559