BitcodeReader.cpp revision 3f7998054a4b92c1823b412f1608259154dd0bbe 
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(bitc::PARAMATTR_BLOCK_ID))
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(bitc::TYPE_BLOCK_ID))
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(bitc::TYPE_SYMTAB_BLOCK_ID))
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(bitc::VALUE_SYMTAB_BLOCK_ID))
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(bitc::CONSTANTS_BLOCK_ID))
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(bitc::MODULE_BLOCK_ID))
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::BLOCKINFO_BLOCK_ID:
809        if (Stream.ReadBlockInfoBlock())
810          return Error("Malformed BlockInfoBlock");
811        break;
812      case bitc::PARAMATTR_BLOCK_ID:
813        if (ParseParamAttrBlock())
814          return true;
815        break;
816      case bitc::TYPE_BLOCK_ID:
817        if (ParseTypeTable())
818          return true;
819        break;
820      case bitc::TYPE_SYMTAB_BLOCK_ID:
821        if (ParseTypeSymbolTable())
822          return true;
823        break;
824      case bitc::VALUE_SYMTAB_BLOCK_ID:
825        if (ParseValueSymbolTable())
826          return true;
827        break;
828      case bitc::CONSTANTS_BLOCK_ID:
829        if (ParseConstants() || ResolveGlobalAndAliasInits())
830          return true;
831        break;
832      case bitc::FUNCTION_BLOCK_ID:
833        // If this is the first function body we've seen, reverse the
834        // FunctionsWithBodies list.
835        if (!HasReversedFunctionsWithBodies) {
836          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
837          HasReversedFunctionsWithBodies = true;
838        }
839
840        if (RememberAndSkipFunctionBody())
841          return true;
842        break;
843      }
844      continue;
845    }
846
847    if (Code == bitc::DEFINE_ABBREV) {
848      Stream.ReadAbbrevRecord();
849      continue;
850    }
851
852    // Read a record.
853    switch (Stream.ReadRecord(Code, Record)) {
854    default: break;  // Default behavior, ignore unknown content.
855    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
856      if (Record.size() < 1)
857        return Error("Malformed MODULE_CODE_VERSION");
858      // Only version #0 is supported so far.
859      if (Record[0] != 0)
860        return Error("Unknown bitstream version!");
861      break;
862    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
863      std::string S;
864      if (ConvertToString(Record, 0, S))
865        return Error("Invalid MODULE_CODE_TRIPLE record");
866      TheModule->setTargetTriple(S);
867      break;
868    }
869    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
870      std::string S;
871      if (ConvertToString(Record, 0, S))
872        return Error("Invalid MODULE_CODE_DATALAYOUT record");
873      TheModule->setDataLayout(S);
874      break;
875    }
876    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
877      std::string S;
878      if (ConvertToString(Record, 0, S))
879        return Error("Invalid MODULE_CODE_ASM record");
880      TheModule->setModuleInlineAsm(S);
881      break;
882    }
883    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
884      std::string S;
885      if (ConvertToString(Record, 0, S))
886        return Error("Invalid MODULE_CODE_DEPLIB record");
887      TheModule->addLibrary(S);
888      break;
889    }
890    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
891      std::string S;
892      if (ConvertToString(Record, 0, S))
893        return Error("Invalid MODULE_CODE_SECTIONNAME record");
894      SectionTable.push_back(S);
895      break;
896    }
897    // GLOBALVAR: [type, isconst, initid,
898    //             linkage, alignment, section, visibility, threadlocal]
899    case bitc::MODULE_CODE_GLOBALVAR: {
900      if (Record.size() < 6)
901        return Error("Invalid MODULE_CODE_GLOBALVAR record");
902      const Type *Ty = getTypeByID(Record[0]);
903      if (!isa<PointerType>(Ty))
904        return Error("Global not a pointer type!");
905      Ty = cast<PointerType>(Ty)->getElementType();
906
907      bool isConstant = Record[1];
908      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
909      unsigned Alignment = (1 << Record[4]) >> 1;
910      std::string Section;
911      if (Record[5]) {
912        if (Record[5]-1 >= SectionTable.size())
913          return Error("Invalid section ID");
914        Section = SectionTable[Record[5]-1];
915      }
916      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
917      if (Record.size() >= 6) Visibility = GetDecodedVisibility(Record[6]);
918      bool isThreadLocal = false;
919      if (Record.size() >= 7) isThreadLocal = Record[7];
920
921      GlobalVariable *NewGV =
922        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule);
923      NewGV->setAlignment(Alignment);
924      if (!Section.empty())
925        NewGV->setSection(Section);
926      NewGV->setVisibility(Visibility);
927      NewGV->setThreadLocal(isThreadLocal);
928
929      ValueList.push_back(NewGV);
930
931      // Remember which value to use for the global initializer.
932      if (unsigned InitID = Record[2])
933        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
934      break;
935    }
936    // FUNCTION:  [type, callingconv, isproto, linkage, alignment, section,
937    //             visibility]
938    case bitc::MODULE_CODE_FUNCTION: {
939      if (Record.size() < 7)
940        return Error("Invalid MODULE_CODE_FUNCTION record");
941      const Type *Ty = getTypeByID(Record[0]);
942      if (!isa<PointerType>(Ty))
943        return Error("Function not a pointer type!");
944      const FunctionType *FTy =
945        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
946      if (!FTy)
947        return Error("Function not a pointer to function type!");
948
949      Function *Func = new Function(FTy, GlobalValue::ExternalLinkage,
950                                    "", TheModule);
951
952      Func->setCallingConv(Record[1]);
953      bool isProto = Record[2];
954      Func->setLinkage(GetDecodedLinkage(Record[3]));
955      Func->setAlignment((1 << Record[4]) >> 1);
956      if (Record[5]) {
957        if (Record[5]-1 >= SectionTable.size())
958          return Error("Invalid section ID");
959        Func->setSection(SectionTable[Record[5]-1]);
960      }
961      Func->setVisibility(GetDecodedVisibility(Record[6]));
962
963      ValueList.push_back(Func);
964
965      // If this is a function with a body, remember the prototype we are
966      // creating now, so that we can match up the body with them later.
967      if (!isProto)
968        FunctionsWithBodies.push_back(Func);
969      break;
970    }
971    // ALIAS: [alias type, aliasee val#, linkage]
972    case bitc::MODULE_CODE_ALIAS: {
973      if (Record.size() < 3)
974        return Error("Invalid MODULE_ALIAS record");
975      const Type *Ty = getTypeByID(Record[0]);
976      if (!isa<PointerType>(Ty))
977        return Error("Function not a pointer type!");
978
979      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
980                                           "", 0, TheModule);
981      ValueList.push_back(NewGA);
982      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
983      break;
984    }
985    /// MODULE_CODE_PURGEVALS: [numvals]
986    case bitc::MODULE_CODE_PURGEVALS:
987      // Trim down the value list to the specified size.
988      if (Record.size() < 1 || Record[0] > ValueList.size())
989        return Error("Invalid MODULE_PURGEVALS record");
990      ValueList.shrinkTo(Record[0]);
991      break;
992    }
993    Record.clear();
994  }
995
996  return Error("Premature end of bitstream");
997}
998
999
1000bool BitcodeReader::ParseBitcode() {
1001  TheModule = 0;
1002
1003  if (Buffer->getBufferSize() & 3)
1004    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1005
1006  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1007  Stream.init(BufPtr, BufPtr+Buffer->getBufferSize());
1008
1009  // Sniff for the signature.
1010  if (Stream.Read(8) != 'B' ||
1011      Stream.Read(8) != 'C' ||
1012      Stream.Read(4) != 0x0 ||
1013      Stream.Read(4) != 0xC ||
1014      Stream.Read(4) != 0xE ||
1015      Stream.Read(4) != 0xD)
1016    return Error("Invalid bitcode signature");
1017
1018  // We expect a number of well-defined blocks, though we don't necessarily
1019  // need to understand them all.
1020  while (!Stream.AtEndOfStream()) {
1021    unsigned Code = Stream.ReadCode();
1022
1023    if (Code != bitc::ENTER_SUBBLOCK)
1024      return Error("Invalid record at top-level");
1025
1026    unsigned BlockID = Stream.ReadSubBlockID();
1027
1028    // We only know the MODULE subblock ID.
1029    switch (BlockID) {
1030    case bitc::BLOCKINFO_BLOCK_ID:
1031      if (Stream.ReadBlockInfoBlock())
1032        return Error("Malformed BlockInfoBlock");
1033      break;
1034    case bitc::MODULE_BLOCK_ID:
1035      if (ParseModule(Buffer->getBufferIdentifier()))
1036        return true;
1037      break;
1038    default:
1039      if (Stream.SkipBlock())
1040        return Error("Malformed block record");
1041      break;
1042    }
1043  }
1044
1045  return false;
1046}
1047
1048
1049bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1050  // If it already is material, ignore the request.
1051  if (!F->hasNotBeenReadFromBytecode()) return false;
1052
1053  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1054    DeferredFunctionInfo.find(F);
1055  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1056
1057  // Move the bit stream to the saved position of the deferred function body and
1058  // restore the real linkage type for the function.
1059  Stream.JumpToBit(DFII->second.first);
1060  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1061  DeferredFunctionInfo.erase(DFII);
1062
1063  if (ParseFunctionBody(F)) {
1064    if (ErrInfo) *ErrInfo = ErrorString;
1065    return true;
1066  }
1067
1068  return false;
1069}
1070
1071Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
1072  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1073    DeferredFunctionInfo.begin();
1074  while (!DeferredFunctionInfo.empty()) {
1075    Function *F = (*I++).first;
1076    assert(F->hasNotBeenReadFromBytecode() &&
1077           "Deserialized function found in map!");
1078    if (materializeFunction(F, ErrInfo))
1079      return 0;
1080  }
1081  return TheModule;
1082}
1083
1084
1085/// ParseFunctionBody - Lazily parse the specified function body block.
1086bool BitcodeReader::ParseFunctionBody(Function *F) {
1087  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1088    return Error("Malformed block record");
1089
1090  unsigned ModuleValueListSize = ValueList.size();
1091
1092  // Add all the function arguments to the value table.
1093  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1094    ValueList.push_back(I);
1095
1096  unsigned NextValueNo = ValueList.size();
1097  BasicBlock *CurBB = 0;
1098  unsigned CurBBNo = 0;
1099
1100  // Read all the records.
1101  SmallVector<uint64_t, 64> Record;
1102  while (1) {
1103    unsigned Code = Stream.ReadCode();
1104    if (Code == bitc::END_BLOCK) {
1105      if (Stream.ReadBlockEnd())
1106        return Error("Error at end of function block");
1107      break;
1108    }
1109
1110    if (Code == bitc::ENTER_SUBBLOCK) {
1111      switch (Stream.ReadSubBlockID()) {
1112      default:  // Skip unknown content.
1113        if (Stream.SkipBlock())
1114          return Error("Malformed block record");
1115        break;
1116      case bitc::CONSTANTS_BLOCK_ID:
1117        if (ParseConstants()) return true;
1118        NextValueNo = ValueList.size();
1119        break;
1120      case bitc::VALUE_SYMTAB_BLOCK_ID:
1121        if (ParseValueSymbolTable()) return true;
1122        break;
1123      }
1124      continue;
1125    }
1126
1127    if (Code == bitc::DEFINE_ABBREV) {
1128      Stream.ReadAbbrevRecord();
1129      continue;
1130    }
1131
1132    // Read a record.
1133    Record.clear();
1134    Instruction *I = 0;
1135    switch (Stream.ReadRecord(Code, Record)) {
1136    default: // Default behavior: reject
1137      return Error("Unknown instruction");
1138    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1139      if (Record.size() < 1 || Record[0] == 0)
1140        return Error("Invalid DECLAREBLOCKS record");
1141      // Create all the basic blocks for the function.
1142      FunctionBBs.resize(Record[0]);
1143      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1144        FunctionBBs[i] = new BasicBlock("", F);
1145      CurBB = FunctionBBs[0];
1146      continue;
1147
1148    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opcode, ty, opval, opval]
1149      if (Record.size() < 4) return Error("Invalid BINOP record");
1150      const Type *Ty = getTypeByID(Record[1]);
1151      int Opc = GetDecodedBinaryOpcode(Record[0], Ty);
1152      Value *LHS = getFnValueByID(Record[2], Ty);
1153      Value *RHS = getFnValueByID(Record[3], Ty);
1154      if (Opc == -1 || Ty == 0 || LHS == 0 || RHS == 0)
1155         return Error("Invalid BINOP record");
1156      I = BinaryOperator::create((Instruction::BinaryOps)Opc, LHS, RHS);
1157      break;
1158    }
1159    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opcode, ty, opty, opval]
1160      if (Record.size() < 4) return Error("Invalid CAST record");
1161      int Opc = GetDecodedCastOpcode(Record[0]);
1162      const Type *ResTy = getTypeByID(Record[1]);
1163      const Type *OpTy = getTypeByID(Record[2]);
1164      Value *Op = getFnValueByID(Record[3], OpTy);
1165      if (Opc == -1 || ResTy == 0 || OpTy == 0 || Op == 0)
1166        return Error("Invalid CAST record");
1167      I = CastInst::create((Instruction::CastOps)Opc, Op, ResTy);
1168      break;
1169    }
1170    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
1171      if (Record.size() < 2 || (Record.size() & 1))
1172        return Error("Invalid GEP record");
1173      const Type *OpTy = getTypeByID(Record[0]);
1174      Value *Op = getFnValueByID(Record[1], OpTy);
1175      if (OpTy == 0 || Op == 0)
1176        return Error("Invalid GEP record");
1177
1178      SmallVector<Value*, 16> GEPIdx;
1179      for (unsigned i = 1, e = Record.size()/2; i != e; ++i) {
1180        const Type *IdxTy = getTypeByID(Record[i*2]);
1181        Value *Idx = getFnValueByID(Record[i*2+1], IdxTy);
1182        if (IdxTy == 0 || Idx == 0)
1183          return Error("Invalid GEP record");
1184        GEPIdx.push_back(Idx);
1185      }
1186
1187      I = new GetElementPtrInst(Op, &GEPIdx[0], GEPIdx.size());
1188      break;
1189    }
1190
1191    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [ty, opval, opval, opval]
1192      if (Record.size() < 4) return Error("Invalid SELECT record");
1193      const Type *Ty = getTypeByID(Record[0]);
1194      Value *Cond = getFnValueByID(Record[1], Type::Int1Ty);
1195      Value *LHS = getFnValueByID(Record[2], Ty);
1196      Value *RHS = getFnValueByID(Record[3], Ty);
1197      if (Ty == 0 || Cond == 0 || LHS == 0 || RHS == 0)
1198        return Error("Invalid SELECT record");
1199      I = new SelectInst(Cond, LHS, RHS);
1200      break;
1201    }
1202
1203    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1204      if (Record.size() < 3) return Error("Invalid EXTRACTELT record");
1205      const Type *OpTy = getTypeByID(Record[0]);
1206      Value *Vec = getFnValueByID(Record[1], OpTy);
1207      Value *Idx = getFnValueByID(Record[2], Type::Int32Ty);
1208      if (OpTy == 0 || Vec == 0 || Idx == 0)
1209        return Error("Invalid EXTRACTELT record");
1210      I = new ExtractElementInst(Vec, Idx);
1211      break;
1212    }
1213
1214    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1215      if (Record.size() < 4) return Error("Invalid INSERTELT record");
1216      const VectorType *OpTy =
1217        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1218      if (OpTy == 0) return Error("Invalid INSERTELT record");
1219      Value *Vec = getFnValueByID(Record[1], OpTy);
1220      Value *Elt = getFnValueByID(Record[2], OpTy->getElementType());
1221      Value *Idx = getFnValueByID(Record[3], Type::Int32Ty);
1222      if (Vec == 0 || Elt == 0 || Idx == 0)
1223        return Error("Invalid INSERTELT record");
1224      I = new InsertElementInst(Vec, Elt, Idx);
1225      break;
1226    }
1227
1228    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [ty,opval,opval,opval]
1229      if (Record.size() < 4) return Error("Invalid SHUFFLEVEC record");
1230      const VectorType *OpTy =
1231        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1232      if (OpTy == 0) return Error("Invalid SHUFFLEVEC record");
1233      Value *Vec1 = getFnValueByID(Record[1], OpTy);
1234      Value *Vec2 = getFnValueByID(Record[2], OpTy);
1235      Value *Mask = getFnValueByID(Record[3],
1236                                   VectorType::get(Type::Int32Ty,
1237                                                   OpTy->getNumElements()));
1238      if (Vec1 == 0 || Vec2 == 0 || Mask == 0)
1239        return Error("Invalid SHUFFLEVEC record");
1240      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1241      break;
1242    }
1243
1244    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1245      if (Record.size() < 4) return Error("Invalid CMP record");
1246      const Type *OpTy = getTypeByID(Record[0]);
1247      Value *LHS = getFnValueByID(Record[1], OpTy);
1248      Value *RHS = getFnValueByID(Record[2], OpTy);
1249      if (OpTy == 0 || LHS == 0 || RHS == 0)
1250        return Error("Invalid CMP record");
1251      if (OpTy->isFPOrFPVector())
1252        I = new FCmpInst((FCmpInst::Predicate)Record[3], LHS, RHS);
1253      else
1254        I = new ICmpInst((ICmpInst::Predicate)Record[3], LHS, RHS);
1255      break;
1256    }
1257
1258    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1259      if (Record.size() == 0) {
1260        I = new ReturnInst();
1261        break;
1262      }
1263      if (Record.size() == 2) {
1264        const Type *OpTy = getTypeByID(Record[0]);
1265        Value *Op = getFnValueByID(Record[1], OpTy);
1266        if (!OpTy || !Op)
1267          return Error("Invalid RET record");
1268        I = new ReturnInst(Op);
1269        break;
1270      }
1271      return Error("Invalid RET record");
1272    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1273      if (Record.size() != 1 && Record.size() != 3)
1274        return Error("Invalid BR record");
1275      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1276      if (TrueDest == 0)
1277        return Error("Invalid BR record");
1278
1279      if (Record.size() == 1)
1280        I = new BranchInst(TrueDest);
1281      else {
1282        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1283        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1284        if (FalseDest == 0 || Cond == 0)
1285          return Error("Invalid BR record");
1286        I = new BranchInst(TrueDest, FalseDest, Cond);
1287      }
1288      break;
1289    }
1290    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1291      if (Record.size() < 3 || (Record.size() & 1) == 0)
1292        return Error("Invalid SWITCH record");
1293      const Type *OpTy = getTypeByID(Record[0]);
1294      Value *Cond = getFnValueByID(Record[1], OpTy);
1295      BasicBlock *Default = getBasicBlock(Record[2]);
1296      if (OpTy == 0 || Cond == 0 || Default == 0)
1297        return Error("Invalid SWITCH record");
1298      unsigned NumCases = (Record.size()-3)/2;
1299      SwitchInst *SI = new SwitchInst(Cond, Default, NumCases);
1300      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1301        ConstantInt *CaseVal =
1302          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1303        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1304        if (CaseVal == 0 || DestBB == 0) {
1305          delete SI;
1306          return Error("Invalid SWITCH record!");
1307        }
1308        SI->addCase(CaseVal, DestBB);
1309      }
1310      I = SI;
1311      break;
1312    }
1313
1314    case bitc::FUNC_CODE_INST_INVOKE: { // INVOKE: [cc,fnty, op0,op1,op2, ...]
1315      if (Record.size() < 5)
1316        return Error("Invalid INVOKE record");
1317      unsigned CCInfo = Record[0];
1318      const PointerType *CalleeTy =
1319        dyn_cast_or_null<PointerType>(getTypeByID(Record[1]));
1320      Value *Callee = getFnValueByID(Record[2], CalleeTy);
1321      BasicBlock *NormalBB = getBasicBlock(Record[3]);
1322      BasicBlock *UnwindBB = getBasicBlock(Record[4]);
1323      if (CalleeTy == 0 || Callee == 0 || NormalBB == 0 || UnwindBB == 0)
1324        return Error("Invalid INVOKE record");
1325
1326      const FunctionType *FTy =
1327        dyn_cast<FunctionType>(CalleeTy->getElementType());
1328
1329      // Check that the right number of fixed parameters are here.
1330      if (FTy == 0 || Record.size() < 5+FTy->getNumParams())
1331        return Error("Invalid INVOKE record");
1332
1333      SmallVector<Value*, 16> Ops;
1334      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1335        Ops.push_back(getFnValueByID(Record[5+i], FTy->getParamType(i)));
1336        if (Ops.back() == 0)
1337          return Error("Invalid INVOKE record");
1338      }
1339
1340      unsigned FirstVarargParam = 5+FTy->getNumParams();
1341      if (FTy->isVarArg()) {
1342        // Read type/value pairs for varargs params.
1343        if ((Record.size()-FirstVarargParam) & 1)
1344          return Error("Invalid INVOKE record");
1345
1346        for (unsigned i = FirstVarargParam, e = Record.size(); i != e; i += 2) {
1347          const Type *ArgTy = getTypeByID(Record[i]);
1348          Ops.push_back(getFnValueByID(Record[i+1], ArgTy));
1349          if (Ops.back() == 0 || ArgTy == 0)
1350            return Error("Invalid INVOKE record");
1351        }
1352      } else {
1353        if (Record.size() != FirstVarargParam)
1354          return Error("Invalid INVOKE record");
1355      }
1356
1357      I = new InvokeInst(Callee, NormalBB, UnwindBB, &Ops[0], Ops.size());
1358      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1359      break;
1360    }
1361    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1362      I = new UnwindInst();
1363      break;
1364    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1365      I = new UnreachableInst();
1366      break;
1367    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, #ops, val0,bb0, ...]
1368      if (Record.size() < 1 || ((Record.size()-1)&1))
1369        return Error("Invalid PHI record");
1370      const Type *Ty = getTypeByID(Record[0]);
1371      if (!Ty) return Error("Invalid PHI record");
1372
1373      PHINode *PN = new PHINode(Ty);
1374      PN->reserveOperandSpace(Record.size()-1);
1375
1376      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
1377        Value *V = getFnValueByID(Record[1+i], Ty);
1378        BasicBlock *BB = getBasicBlock(Record[2+i]);
1379        if (!V || !BB) return Error("Invalid PHI record");
1380        PN->addIncoming(V, BB);
1381      }
1382      I = PN;
1383      break;
1384    }
1385
1386    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1387      if (Record.size() < 3)
1388        return Error("Invalid MALLOC record");
1389      const PointerType *Ty =
1390        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1391      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1392      unsigned Align = Record[2];
1393      if (!Ty || !Size) return Error("Invalid MALLOC record");
1394      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1395      break;
1396    }
1397    case bitc::FUNC_CODE_INST_FREE: { // FREE: [opty, op]
1398      if (Record.size() < 2)
1399        return Error("Invalid FREE record");
1400      const Type *OpTy = getTypeByID(Record[0]);
1401      Value *Op = getFnValueByID(Record[1], OpTy);
1402      if (!OpTy || !Op)
1403        return Error("Invalid FREE record");
1404      I = new FreeInst(Op);
1405      break;
1406    }
1407    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1408      if (Record.size() < 3)
1409        return Error("Invalid ALLOCA record");
1410      const PointerType *Ty =
1411        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1412      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1413      unsigned Align = Record[2];
1414      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1415      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1416      break;
1417    }
1418    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1419      if (Record.size() < 4)
1420        return Error("Invalid LOAD record");
1421      const Type *OpTy = getTypeByID(Record[0]);
1422      Value *Op = getFnValueByID(Record[1], OpTy);
1423      if (!OpTy || !Op)
1424        return Error("Invalid LOAD record");
1425      I = new LoadInst(Op, "", Record[3], (1 << Record[2]) >> 1);
1426      break;
1427    }
1428    case bitc::FUNC_CODE_INST_STORE: { // STORE:[ptrty,val,ptr, align, vol]
1429      if (Record.size() < 5)
1430        return Error("Invalid LOAD record");
1431      const PointerType *OpTy =
1432        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1433      Value *Op = getFnValueByID(Record[1], OpTy ? OpTy->getElementType() : 0);
1434      Value *Ptr = getFnValueByID(Record[2], OpTy);
1435      if (!OpTy || !Op || !Ptr)
1436        return Error("Invalid STORE record");
1437      I = new StoreInst(Op, Ptr, Record[4], (1 << Record[3]) >> 1);
1438      break;
1439    }
1440    case bitc::FUNC_CODE_INST_CALL: { // CALL: [cc, fnty, fnid, arg0, arg1...]
1441      if (Record.size() < 3)
1442        return Error("Invalid CALL record");
1443      unsigned CCInfo = Record[0];
1444      const PointerType *OpTy =
1445        dyn_cast_or_null<PointerType>(getTypeByID(Record[1]));
1446      const FunctionType *FTy = 0;
1447      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1448      Value *Callee = getFnValueByID(Record[2], OpTy);
1449      if (!FTy || !Callee || Record.size() < FTy->getNumParams()+3)
1450        return Error("Invalid CALL record");
1451
1452      SmallVector<Value*, 16> Args;
1453      // Read the fixed params.
1454      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1455        Args.push_back(getFnValueByID(Record[i+3], FTy->getParamType(i)));
1456        if (Args.back() == 0) return Error("Invalid CALL record");
1457      }
1458
1459
1460      // Read type/value pairs for varargs params.
1461      unsigned NextArg = FTy->getNumParams()+3;
1462      if (!FTy->isVarArg()) {
1463        if (NextArg != Record.size())
1464          return Error("Invalid CALL record");
1465      } else {
1466        if ((Record.size()-NextArg) & 1)
1467          return Error("Invalid CALL record");
1468        for (unsigned e = Record.size(); NextArg != e; NextArg += 2) {
1469          Args.push_back(getFnValueByID(Record[NextArg+1],
1470                                        getTypeByID(Record[NextArg])));
1471          if (Args.back() == 0) return Error("Invalid CALL record");
1472        }
1473      }
1474
1475      I = new CallInst(Callee, &Args[0], Args.size());
1476      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1477      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1478      break;
1479    }
1480    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1481      if (Record.size() < 3)
1482        return Error("Invalid VAARG record");
1483      const Type *OpTy = getTypeByID(Record[0]);
1484      Value *Op = getFnValueByID(Record[1], OpTy);
1485      const Type *ResTy = getTypeByID(Record[2]);
1486      if (!OpTy || !Op || !ResTy)
1487        return Error("Invalid VAARG record");
1488      I = new VAArgInst(Op, ResTy);
1489      break;
1490    }
1491    }
1492
1493    // Add instruction to end of current BB.  If there is no current BB, reject
1494    // this file.
1495    if (CurBB == 0) {
1496      delete I;
1497      return Error("Invalid instruction with no BB");
1498    }
1499    CurBB->getInstList().push_back(I);
1500
1501    // If this was a terminator instruction, move to the next block.
1502    if (isa<TerminatorInst>(I)) {
1503      ++CurBBNo;
1504      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1505    }
1506
1507    // Non-void values get registered in the value table for future use.
1508    if (I && I->getType() != Type::VoidTy)
1509      ValueList.AssignValue(I, NextValueNo++);
1510  }
1511
1512  // Check the function list for unresolved values.
1513  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1514    if (A->getParent() == 0) {
1515      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1516      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1517        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1518          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1519          delete A;
1520        }
1521      }
1522      return Error("Never resolved value found in function!");
1523    }
1524  }
1525
1526  // Trim the value list down to the size it was before we parsed this function.
1527  ValueList.shrinkTo(ModuleValueListSize);
1528  std::vector<BasicBlock*>().swap(FunctionBBs);
1529
1530  return false;
1531}
1532
1533
1534//===----------------------------------------------------------------------===//
1535// External interface
1536//===----------------------------------------------------------------------===//
1537
1538/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1539///
1540ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1541                                               std::string *ErrMsg) {
1542  BitcodeReader *R = new BitcodeReader(Buffer);
1543  if (R->ParseBitcode()) {
1544    if (ErrMsg)
1545      *ErrMsg = R->getErrorString();
1546
1547    // Don't let the BitcodeReader dtor delete 'Buffer'.
1548    R->releaseMemoryBuffer();
1549    delete R;
1550    return 0;
1551  }
1552  return R;
1553}
1554
1555/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
1556/// If an error occurs, return null and fill in *ErrMsg if non-null.
1557Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
1558  BitcodeReader *R;
1559  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
1560  if (!R) return 0;
1561
1562  // Read the whole module, get a pointer to it, tell ModuleProvider not to
1563  // delete it when its dtor is run.
1564  Module *M = R->releaseModule(ErrMsg);
1565
1566  // Don't let the BitcodeReader dtor delete 'Buffer'.
1567  R->releaseMemoryBuffer();
1568  delete R;
1569  return M;
1570}
1571