BitcodeReader.cpp revision 964b5f2701ff5c5bad942aae2661149002fad01e 
1//===- BitcodeReader.cpp - Internal BitcodeReader implementation ----------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by Chris Lattner and is distributed under
6// the University of Illinois Open Source License.  See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This header defines the BitcodeReader class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Bitcode/ReaderWriter.h"
15#include "BitcodeReader.h"
16#include "llvm/Constants.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/Instructions.h"
19#include "llvm/Module.h"
20#include "llvm/ParameterAttributes.h"
21#include "llvm/ADT/SmallString.h"
22#include "llvm/Support/MathExtras.h"
23#include "llvm/Support/MemoryBuffer.h"
24using namespace llvm;
25
26BitcodeReader::~BitcodeReader() {
27  delete Buffer;
28}
29
30//===----------------------------------------------------------------------===//
31//  Helper functions to implement forward reference resolution, etc.
32//===----------------------------------------------------------------------===//
33
34/// ConvertToString - Convert a string from a record into an std::string, return
35/// true on failure.
36template<typename StrTy>
37static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
38                            StrTy &Result) {
39  if (Record.size() < Idx+1 || Record.size() < Record[Idx]+Idx+1)
40    return true;
41
42  for (unsigned i = 0, e = Record[Idx]; i != e; ++i)
43    Result += (char)Record[Idx+i+1];
44  return false;
45}
46
47static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
48  switch (Val) {
49  default: // Map unknown/new linkages to external
50  case 0: return GlobalValue::ExternalLinkage;
51  case 1: return GlobalValue::WeakLinkage;
52  case 2: return GlobalValue::AppendingLinkage;
53  case 3: return GlobalValue::InternalLinkage;
54  case 4: return GlobalValue::LinkOnceLinkage;
55  case 5: return GlobalValue::DLLImportLinkage;
56  case 6: return GlobalValue::DLLExportLinkage;
57  case 7: return GlobalValue::ExternalWeakLinkage;
58  }
59}
60
61static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
62  switch (Val) {
63  default: // Map unknown visibilities to default.
64  case 0: return GlobalValue::DefaultVisibility;
65  case 1: return GlobalValue::HiddenVisibility;
66  case 2: return GlobalValue::ProtectedVisibility;
67  }
68}
69
70static int GetDecodedCastOpcode(unsigned Val) {
71  switch (Val) {
72  default: return -1;
73  case bitc::CAST_TRUNC   : return Instruction::Trunc;
74  case bitc::CAST_ZEXT    : return Instruction::ZExt;
75  case bitc::CAST_SEXT    : return Instruction::SExt;
76  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
77  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
78  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
79  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
80  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
81  case bitc::CAST_FPEXT   : return Instruction::FPExt;
82  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
83  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
84  case bitc::CAST_BITCAST : return Instruction::BitCast;
85  }
86}
87static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
88  switch (Val) {
89  default: return -1;
90  case bitc::BINOP_ADD:  return Instruction::Add;
91  case bitc::BINOP_SUB:  return Instruction::Sub;
92  case bitc::BINOP_MUL:  return Instruction::Mul;
93  case bitc::BINOP_UDIV: return Instruction::UDiv;
94  case bitc::BINOP_SDIV:
95    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
96  case bitc::BINOP_UREM: return Instruction::URem;
97  case bitc::BINOP_SREM:
98    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
99  case bitc::BINOP_SHL:  return Instruction::Shl;
100  case bitc::BINOP_LSHR: return Instruction::LShr;
101  case bitc::BINOP_ASHR: return Instruction::AShr;
102  case bitc::BINOP_AND:  return Instruction::And;
103  case bitc::BINOP_OR:   return Instruction::Or;
104  case bitc::BINOP_XOR:  return Instruction::Xor;
105  }
106}
107
108
109namespace {
110  /// @brief A class for maintaining the slot number definition
111  /// as a placeholder for the actual definition for forward constants defs.
112  class ConstantPlaceHolder : public ConstantExpr {
113    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
114    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
115  public:
116    Use Op;
117    ConstantPlaceHolder(const Type *Ty)
118      : ConstantExpr(Ty, Instruction::UserOp1, &Op, 1),
119        Op(UndefValue::get(Type::Int32Ty), this) {
120    }
121  };
122}
123
124Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
125                                                    const Type *Ty) {
126  if (Idx >= size()) {
127    // Insert a bunch of null values.
128    Uses.resize(Idx+1);
129    OperandList = &Uses[0];
130    NumOperands = Idx+1;
131  }
132
133  if (Value *V = Uses[Idx]) {
134    assert(Ty == V->getType() && "Type mismatch in constant table!");
135    return cast<Constant>(V);
136  }
137
138  // Create and return a placeholder, which will later be RAUW'd.
139  Constant *C = new ConstantPlaceHolder(Ty);
140  Uses[Idx].init(C, this);
141  return C;
142}
143
144Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
145  if (Idx >= size()) {
146    // Insert a bunch of null values.
147    Uses.resize(Idx+1);
148    OperandList = &Uses[0];
149    NumOperands = Idx+1;
150  }
151
152  if (Value *V = Uses[Idx]) {
153    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
154    return V;
155  }
156
157  // No type specified, must be invalid reference.
158  if (Ty == 0) return 0;
159
160  // Create and return a placeholder, which will later be RAUW'd.
161  Value *V = new Argument(Ty);
162  Uses[Idx].init(V, this);
163  return V;
164}
165
166
167const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
168  // If the TypeID is in range, return it.
169  if (ID < TypeList.size())
170    return TypeList[ID].get();
171  if (!isTypeTable) return 0;
172
173  // The type table allows forward references.  Push as many Opaque types as
174  // needed to get up to ID.
175  while (TypeList.size() <= ID)
176    TypeList.push_back(OpaqueType::get());
177  return TypeList.back().get();
178}
179
180//===----------------------------------------------------------------------===//
181//  Functions for parsing blocks from the bitcode file
182//===----------------------------------------------------------------------===//
183
184bool BitcodeReader::ParseParamAttrBlock() {
185  if (Stream.EnterSubBlock())
186    return Error("Malformed block record");
187
188  if (!ParamAttrs.empty())
189    return Error("Multiple PARAMATTR blocks found!");
190
191  SmallVector<uint64_t, 64> Record;
192
193  ParamAttrsVector Attrs;
194
195  // Read all the records.
196  while (1) {
197    unsigned Code = Stream.ReadCode();
198    if (Code == bitc::END_BLOCK) {
199      if (Stream.ReadBlockEnd())
200        return Error("Error at end of PARAMATTR block");
201      return false;
202    }
203
204    if (Code == bitc::ENTER_SUBBLOCK) {
205      // No known subblocks, always skip them.
206      Stream.ReadSubBlockID();
207      if (Stream.SkipBlock())
208        return Error("Malformed block record");
209      continue;
210    }
211
212    if (Code == bitc::DEFINE_ABBREV) {
213      Stream.ReadAbbrevRecord();
214      continue;
215    }
216
217    // Read a record.
218    Record.clear();
219    switch (Stream.ReadRecord(Code, Record)) {
220    default:  // Default behavior: ignore.
221      break;
222    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
223      if (Record.size() & 1)
224        return Error("Invalid ENTRY record");
225
226      ParamAttrsWithIndex PAWI;
227      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
228        PAWI.index = Record[i];
229        PAWI.attrs = Record[i+1];
230        Attrs.push_back(PAWI);
231      }
232      ParamAttrs.push_back(ParamAttrsList::get(Attrs));
233      Attrs.clear();
234      break;
235    }
236    }
237  }
238}
239
240
241bool BitcodeReader::ParseTypeTable() {
242  if (Stream.EnterSubBlock())
243    return Error("Malformed block record");
244
245  if (!TypeList.empty())
246    return Error("Multiple TYPE_BLOCKs found!");
247
248  SmallVector<uint64_t, 64> Record;
249  unsigned NumRecords = 0;
250
251  // Read all the records for this type table.
252  while (1) {
253    unsigned Code = Stream.ReadCode();
254    if (Code == bitc::END_BLOCK) {
255      if (NumRecords != TypeList.size())
256        return Error("Invalid type forward reference in TYPE_BLOCK");
257      if (Stream.ReadBlockEnd())
258        return Error("Error at end of type table block");
259      return false;
260    }
261
262    if (Code == bitc::ENTER_SUBBLOCK) {
263      // No known subblocks, always skip them.
264      Stream.ReadSubBlockID();
265      if (Stream.SkipBlock())
266        return Error("Malformed block record");
267      continue;
268    }
269
270    if (Code == bitc::DEFINE_ABBREV) {
271      Stream.ReadAbbrevRecord();
272      continue;
273    }
274
275    // Read a record.
276    Record.clear();
277    const Type *ResultTy = 0;
278    switch (Stream.ReadRecord(Code, Record)) {
279    default:  // Default behavior: unknown type.
280      ResultTy = 0;
281      break;
282    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
283      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
284      // type list.  This allows us to reserve space.
285      if (Record.size() < 1)
286        return Error("Invalid TYPE_CODE_NUMENTRY record");
287      TypeList.reserve(Record[0]);
288      continue;
289    case bitc::TYPE_CODE_VOID:      // VOID
290      ResultTy = Type::VoidTy;
291      break;
292    case bitc::TYPE_CODE_FLOAT:     // FLOAT
293      ResultTy = Type::FloatTy;
294      break;
295    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
296      ResultTy = Type::DoubleTy;
297      break;
298    case bitc::TYPE_CODE_LABEL:     // LABEL
299      ResultTy = Type::LabelTy;
300      break;
301    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
302      ResultTy = 0;
303      break;
304    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
305      if (Record.size() < 1)
306        return Error("Invalid Integer type record");
307
308      ResultTy = IntegerType::get(Record[0]);
309      break;
310    case bitc::TYPE_CODE_POINTER:   // POINTER: [pointee type]
311      if (Record.size() < 1)
312        return Error("Invalid POINTER type record");
313      ResultTy = PointerType::get(getTypeByID(Record[0], true));
314      break;
315    case bitc::TYPE_CODE_FUNCTION: {
316      // FUNCTION: [vararg, attrid, retty, #pararms, paramty N]
317      if (Record.size() < 4 || Record.size() < Record[3]+4)
318        return Error("Invalid FUNCTION type record");
319      std::vector<const Type*> ArgTys;
320      for (unsigned i = 0, e = Record[3]; i != e; ++i)
321        ArgTys.push_back(getTypeByID(Record[4+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, #elts, eltty x N]
328      if (Record.size() < 2 || Record.size() < Record[1]+2)
329        return Error("Invalid STRUCT type record");
330      std::vector<const Type*> EltTys;
331      for (unsigned i = 0, e = Record[1]; i != e; ++i)
332        EltTys.push_back(getTypeByID(Record[2+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, namelen, 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, namelen, 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, n x intval]
595      if (!isa<IntegerType>(CurTy) || Record.empty() ||
596          Record.size() < Record[0]+1)
597        return Error("Invalid WIDE_INTEGER record");
598
599      unsigned NumWords = Record[0];
600      SmallVector<uint64_t, 8> Words;
601      Words.resize(NumWords);
602      for (unsigned i = 0; i != NumWords; ++i)
603        Words[i] = DecodeSignRotatedValue(Record[i+1]);
604      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
605                                 NumWords, &Words[0]));
606      break;
607    }
608    case bitc::CST_CODE_FLOAT:     // FLOAT: [fpval]
609      if (Record.empty())
610        return Error("Invalid FLOAT record");
611      if (CurTy == Type::FloatTy)
612        V = ConstantFP::get(CurTy, BitsToFloat(Record[0]));
613      else if (CurTy == Type::DoubleTy)
614        V = ConstantFP::get(CurTy, BitsToDouble(Record[0]));
615      else
616        V = UndefValue::get(CurTy);
617      break;
618
619    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n, n x value number]
620      if (Record.empty() || Record.size() < Record[0]+1)
621        return Error("Invalid CST_AGGREGATE record");
622
623      unsigned Size = Record[0];
624      std::vector<Constant*> Elts;
625
626      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
627        for (unsigned i = 0; i != Size; ++i)
628          Elts.push_back(ValueList.getConstantFwdRef(Record[i+1],
629                                                     STy->getElementType(i)));
630        V = ConstantStruct::get(STy, Elts);
631      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
632        const Type *EltTy = ATy->getElementType();
633        for (unsigned i = 0; i != Size; ++i)
634          Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], EltTy));
635        V = ConstantArray::get(ATy, Elts);
636      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
637        const Type *EltTy = VTy->getElementType();
638        for (unsigned i = 0; i != Size; ++i)
639          Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], EltTy));
640        V = ConstantVector::get(Elts);
641      } else {
642        V = UndefValue::get(CurTy);
643      }
644      break;
645    }
646
647    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
648      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
649      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
650      if (Opc < 0) {
651        V = UndefValue::get(CurTy);  // Unknown binop.
652      } else {
653        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
654        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
655        V = ConstantExpr::get(Opc, LHS, RHS);
656      }
657      break;
658    }
659    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
660      if (Record.size() < 3) return Error("Invalid CE_CAST record");
661      int Opc = GetDecodedCastOpcode(Record[0]);
662      if (Opc < 0) {
663        V = UndefValue::get(CurTy);  // Unknown cast.
664      } else {
665        const Type *OpTy = getTypeByID(Record[1]);
666        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
667        V = ConstantExpr::getCast(Opc, Op, CurTy);
668      }
669      break;
670    }
671    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
672      if ((Record.size() & 1) == 0) return Error("Invalid CE_GEP record");
673      SmallVector<Constant*, 16> Elts;
674      for (unsigned i = 1, e = Record.size(); i != e; i += 2) {
675        const Type *ElTy = getTypeByID(Record[i]);
676        if (!ElTy) return Error("Invalid CE_GEP record");
677        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
678      }
679      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
680      break;
681    }
682    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
683      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
684      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
685                                                              Type::Int1Ty),
686                                  ValueList.getConstantFwdRef(Record[1],CurTy),
687                                  ValueList.getConstantFwdRef(Record[2],CurTy));
688      break;
689    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
690      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
691      const VectorType *OpTy =
692        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
693      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
694      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
695      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
696                                                  OpTy->getElementType());
697      V = ConstantExpr::getExtractElement(Op0, Op1);
698      break;
699    }
700    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
701      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
702      if (Record.size() < 3 || OpTy == 0)
703        return Error("Invalid CE_INSERTELT record");
704      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
705      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
706                                                  OpTy->getElementType());
707      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
708      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
709      break;
710    }
711    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
712      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
713      if (Record.size() < 3 || OpTy == 0)
714        return Error("Invalid CE_INSERTELT record");
715      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
716      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
717      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
718      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
719      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
720      break;
721    }
722    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
723      if (Record.size() < 4) return Error("Invalid CE_CMP record");
724      const Type *OpTy = getTypeByID(Record[0]);
725      if (OpTy == 0) return Error("Invalid CE_CMP record");
726      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
727      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
728
729      if (OpTy->isFloatingPoint())
730        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
731      else
732        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
733      break;
734    }
735    }
736
737    ValueList.AssignValue(V, NextCstNo);
738    ++NextCstNo;
739  }
740}
741
742/// RememberAndSkipFunctionBody - When we see the block for a function body,
743/// remember where it is and then skip it.  This lets us lazily deserialize the
744/// functions.
745bool BitcodeReader::RememberAndSkipFunctionBody() {
746  // Get the function we are talking about.
747  if (FunctionsWithBodies.empty())
748    return Error("Insufficient function protos");
749
750  Function *Fn = FunctionsWithBodies.back();
751  FunctionsWithBodies.pop_back();
752
753  // Save the current stream state.
754  uint64_t CurBit = Stream.GetCurrentBitNo();
755  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
756
757  // Set the functions linkage to GhostLinkage so we know it is lazily
758  // deserialized.
759  Fn->setLinkage(GlobalValue::GhostLinkage);
760
761  // Skip over the function block for now.
762  if (Stream.SkipBlock())
763    return Error("Malformed block record");
764  return false;
765}
766
767bool BitcodeReader::ParseModule(const std::string &ModuleID) {
768  // Reject multiple MODULE_BLOCK's in a single bitstream.
769  if (TheModule)
770    return Error("Multiple MODULE_BLOCKs in same stream");
771
772  if (Stream.EnterSubBlock())
773    return Error("Malformed block record");
774
775  // Otherwise, create the module.
776  TheModule = new Module(ModuleID);
777
778  SmallVector<uint64_t, 64> Record;
779  std::vector<std::string> SectionTable;
780
781  // Read all the records for this module.
782  while (!Stream.AtEndOfStream()) {
783    unsigned Code = Stream.ReadCode();
784    if (Code == bitc::END_BLOCK) {
785      if (Stream.ReadBlockEnd())
786        return Error("Error at end of module block");
787
788      // Patch the initializers for globals and aliases up.
789      ResolveGlobalAndAliasInits();
790      if (!GlobalInits.empty() || !AliasInits.empty())
791        return Error("Malformed global initializer set");
792      if (!FunctionsWithBodies.empty())
793        return Error("Too few function bodies found");
794
795      // Force deallocation of memory for these vectors to favor the client that
796      // want lazy deserialization.
797      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
798      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
799      std::vector<Function*>().swap(FunctionsWithBodies);
800      return false;
801    }
802
803    if (Code == bitc::ENTER_SUBBLOCK) {
804      switch (Stream.ReadSubBlockID()) {
805      default:  // Skip unknown content.
806        if (Stream.SkipBlock())
807          return Error("Malformed block record");
808        break;
809      case bitc::PARAMATTR_BLOCK_ID:
810        if (ParseParamAttrBlock())
811          return true;
812        break;
813      case bitc::TYPE_BLOCK_ID:
814        if (ParseTypeTable())
815          return true;
816        break;
817      case bitc::TYPE_SYMTAB_BLOCK_ID:
818        if (ParseTypeSymbolTable())
819          return true;
820        break;
821      case bitc::VALUE_SYMTAB_BLOCK_ID:
822        if (ParseValueSymbolTable())
823          return true;
824        break;
825      case bitc::CONSTANTS_BLOCK_ID:
826        if (ParseConstants() || ResolveGlobalAndAliasInits())
827          return true;
828        break;
829      case bitc::FUNCTION_BLOCK_ID:
830        // If this is the first function body we've seen, reverse the
831        // FunctionsWithBodies list.
832        if (!HasReversedFunctionsWithBodies) {
833          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
834          HasReversedFunctionsWithBodies = true;
835        }
836
837        if (RememberAndSkipFunctionBody())
838          return true;
839        break;
840      }
841      continue;
842    }
843
844    if (Code == bitc::DEFINE_ABBREV) {
845      Stream.ReadAbbrevRecord();
846      continue;
847    }
848
849    // Read a record.
850    switch (Stream.ReadRecord(Code, Record)) {
851    default: break;  // Default behavior, ignore unknown content.
852    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
853      if (Record.size() < 1)
854        return Error("Malformed MODULE_CODE_VERSION");
855      // Only version #0 is supported so far.
856      if (Record[0] != 0)
857        return Error("Unknown bitstream version!");
858      break;
859    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strlen, strchr x N]
860      std::string S;
861      if (ConvertToString(Record, 0, S))
862        return Error("Invalid MODULE_CODE_TRIPLE record");
863      TheModule->setTargetTriple(S);
864      break;
865    }
866    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strlen, strchr x N]
867      std::string S;
868      if (ConvertToString(Record, 0, S))
869        return Error("Invalid MODULE_CODE_DATALAYOUT record");
870      TheModule->setDataLayout(S);
871      break;
872    }
873    case bitc::MODULE_CODE_ASM: {  // ASM: [strlen, strchr x N]
874      std::string S;
875      if (ConvertToString(Record, 0, S))
876        return Error("Invalid MODULE_CODE_ASM record");
877      TheModule->setModuleInlineAsm(S);
878      break;
879    }
880    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strlen, strchr x N]
881      std::string S;
882      if (ConvertToString(Record, 0, S))
883        return Error("Invalid MODULE_CODE_DEPLIB record");
884      TheModule->addLibrary(S);
885      break;
886    }
887    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strlen, strchr x N]
888      std::string S;
889      if (ConvertToString(Record, 0, S))
890        return Error("Invalid MODULE_CODE_SECTIONNAME record");
891      SectionTable.push_back(S);
892      break;
893    }
894    // GLOBALVAR: [type, isconst, initid,
895    //             linkage, alignment, section, visibility, threadlocal]
896    case bitc::MODULE_CODE_GLOBALVAR: {
897      if (Record.size() < 6)
898        return Error("Invalid MODULE_CODE_GLOBALVAR record");
899      const Type *Ty = getTypeByID(Record[0]);
900      if (!isa<PointerType>(Ty))
901        return Error("Global not a pointer type!");
902      Ty = cast<PointerType>(Ty)->getElementType();
903
904      bool isConstant = Record[1];
905      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
906      unsigned Alignment = (1 << Record[4]) >> 1;
907      std::string Section;
908      if (Record[5]) {
909        if (Record[5]-1 >= SectionTable.size())
910          return Error("Invalid section ID");
911        Section = SectionTable[Record[5]-1];
912      }
913      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
914      if (Record.size() >= 6) Visibility = GetDecodedVisibility(Record[6]);
915      bool isThreadLocal = false;
916      if (Record.size() >= 7) isThreadLocal = Record[7];
917
918      GlobalVariable *NewGV =
919        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule);
920      NewGV->setAlignment(Alignment);
921      if (!Section.empty())
922        NewGV->setSection(Section);
923      NewGV->setVisibility(Visibility);
924      NewGV->setThreadLocal(isThreadLocal);
925
926      ValueList.push_back(NewGV);
927
928      // Remember which value to use for the global initializer.
929      if (unsigned InitID = Record[2])
930        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
931      break;
932    }
933    // FUNCTION:  [type, callingconv, isproto, linkage, alignment, section,
934    //             visibility]
935    case bitc::MODULE_CODE_FUNCTION: {
936      if (Record.size() < 7)
937        return Error("Invalid MODULE_CODE_FUNCTION record");
938      const Type *Ty = getTypeByID(Record[0]);
939      if (!isa<PointerType>(Ty))
940        return Error("Function not a pointer type!");
941      const FunctionType *FTy =
942        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
943      if (!FTy)
944        return Error("Function not a pointer to function type!");
945
946      Function *Func = new Function(FTy, GlobalValue::ExternalLinkage,
947                                    "", TheModule);
948
949      Func->setCallingConv(Record[1]);
950      bool isProto = Record[2];
951      Func->setLinkage(GetDecodedLinkage(Record[3]));
952      Func->setAlignment((1 << Record[4]) >> 1);
953      if (Record[5]) {
954        if (Record[5]-1 >= SectionTable.size())
955          return Error("Invalid section ID");
956        Func->setSection(SectionTable[Record[5]-1]);
957      }
958      Func->setVisibility(GetDecodedVisibility(Record[6]));
959
960      ValueList.push_back(Func);
961
962      // If this is a function with a body, remember the prototype we are
963      // creating now, so that we can match up the body with them later.
964      if (!isProto)
965        FunctionsWithBodies.push_back(Func);
966      break;
967    }
968    // ALIAS: [alias type, aliasee val#, linkage]
969    case bitc::MODULE_CODE_ALIAS: {
970      if (Record.size() < 3)
971        return Error("Invalid MODULE_ALIAS record");
972      const Type *Ty = getTypeByID(Record[0]);
973      if (!isa<PointerType>(Ty))
974        return Error("Function not a pointer type!");
975
976      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
977                                           "", 0, TheModule);
978      ValueList.push_back(NewGA);
979      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
980      break;
981    }
982    /// MODULE_CODE_PURGEVALS: [numvals]
983    case bitc::MODULE_CODE_PURGEVALS:
984      // Trim down the value list to the specified size.
985      if (Record.size() < 1 || Record[0] > ValueList.size())
986        return Error("Invalid MODULE_PURGEVALS record");
987      ValueList.shrinkTo(Record[0]);
988      break;
989    }
990    Record.clear();
991  }
992
993  return Error("Premature end of bitstream");
994}
995
996
997bool BitcodeReader::ParseBitcode() {
998  TheModule = 0;
999
1000  if (Buffer->getBufferSize() & 3)
1001    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1002
1003  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1004  Stream.init(BufPtr, BufPtr+Buffer->getBufferSize());
1005
1006  // Sniff for the signature.
1007  if (Stream.Read(8) != 'B' ||
1008      Stream.Read(8) != 'C' ||
1009      Stream.Read(4) != 0x0 ||
1010      Stream.Read(4) != 0xC ||
1011      Stream.Read(4) != 0xE ||
1012      Stream.Read(4) != 0xD)
1013    return Error("Invalid bitcode signature");
1014
1015  // We expect a number of well-defined blocks, though we don't necessarily
1016  // need to understand them all.
1017  while (!Stream.AtEndOfStream()) {
1018    unsigned Code = Stream.ReadCode();
1019
1020    if (Code != bitc::ENTER_SUBBLOCK)
1021      return Error("Invalid record at top-level");
1022
1023    unsigned BlockID = Stream.ReadSubBlockID();
1024
1025    // We only know the MODULE subblock ID.
1026    if (BlockID == bitc::MODULE_BLOCK_ID) {
1027      if (ParseModule(Buffer->getBufferIdentifier()))
1028        return true;
1029    } else if (Stream.SkipBlock()) {
1030      return Error("Malformed block record");
1031    }
1032  }
1033
1034  return false;
1035}
1036
1037
1038bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1039  // If it already is material, ignore the request.
1040  if (!F->hasNotBeenReadFromBytecode()) return false;
1041
1042  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1043    DeferredFunctionInfo.find(F);
1044  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1045
1046  // Move the bit stream to the saved position of the deferred function body and
1047  // restore the real linkage type for the function.
1048  Stream.JumpToBit(DFII->second.first);
1049  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1050  DeferredFunctionInfo.erase(DFII);
1051
1052  if (ParseFunctionBody(F)) {
1053    if (ErrInfo) *ErrInfo = ErrorString;
1054    return true;
1055  }
1056
1057  return false;
1058}
1059
1060Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
1061  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1062    DeferredFunctionInfo.begin();
1063  while (!DeferredFunctionInfo.empty()) {
1064    Function *F = (*I++).first;
1065    assert(F->hasNotBeenReadFromBytecode() &&
1066           "Deserialized function found in map!");
1067    if (materializeFunction(F, ErrInfo))
1068      return 0;
1069  }
1070  return TheModule;
1071}
1072
1073
1074/// ParseFunctionBody - Lazily parse the specified function body block.
1075bool BitcodeReader::ParseFunctionBody(Function *F) {
1076  if (Stream.EnterSubBlock())
1077    return Error("Malformed block record");
1078
1079  unsigned ModuleValueListSize = ValueList.size();
1080
1081  // Add all the function arguments to the value table.
1082  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1083    ValueList.push_back(I);
1084
1085  unsigned NextValueNo = ValueList.size();
1086  BasicBlock *CurBB = 0;
1087  unsigned CurBBNo = 0;
1088
1089  // Read all the records.
1090  SmallVector<uint64_t, 64> Record;
1091  while (1) {
1092    unsigned Code = Stream.ReadCode();
1093    if (Code == bitc::END_BLOCK) {
1094      if (Stream.ReadBlockEnd())
1095        return Error("Error at end of function block");
1096      break;
1097    }
1098
1099    if (Code == bitc::ENTER_SUBBLOCK) {
1100      switch (Stream.ReadSubBlockID()) {
1101      default:  // Skip unknown content.
1102        if (Stream.SkipBlock())
1103          return Error("Malformed block record");
1104        break;
1105      case bitc::CONSTANTS_BLOCK_ID:
1106        if (ParseConstants()) return true;
1107        NextValueNo = ValueList.size();
1108        break;
1109      case bitc::VALUE_SYMTAB_BLOCK_ID:
1110        if (ParseValueSymbolTable()) return true;
1111        break;
1112      }
1113      continue;
1114    }
1115
1116    if (Code == bitc::DEFINE_ABBREV) {
1117      Stream.ReadAbbrevRecord();
1118      continue;
1119    }
1120
1121    // Read a record.
1122    Record.clear();
1123    Instruction *I = 0;
1124    switch (Stream.ReadRecord(Code, Record)) {
1125    default: // Default behavior: reject
1126      return Error("Unknown instruction");
1127    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1128      if (Record.size() < 1 || Record[0] == 0)
1129        return Error("Invalid DECLAREBLOCKS record");
1130      // Create all the basic blocks for the function.
1131      FunctionBBs.resize(Record[0]);
1132      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1133        FunctionBBs[i] = new BasicBlock("", F);
1134      CurBB = FunctionBBs[0];
1135      continue;
1136
1137    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opcode, ty, opval, opval]
1138      if (Record.size() < 4) return Error("Invalid BINOP record");
1139      const Type *Ty = getTypeByID(Record[1]);
1140      int Opc = GetDecodedBinaryOpcode(Record[0], Ty);
1141      Value *LHS = getFnValueByID(Record[2], Ty);
1142      Value *RHS = getFnValueByID(Record[3], Ty);
1143      if (Opc == -1 || Ty == 0 || LHS == 0 || RHS == 0)
1144         return Error("Invalid BINOP record");
1145      I = BinaryOperator::create((Instruction::BinaryOps)Opc, LHS, RHS);
1146      break;
1147    }
1148    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opcode, ty, opty, opval]
1149      if (Record.size() < 4) return Error("Invalid CAST record");
1150      int Opc = GetDecodedCastOpcode(Record[0]);
1151      const Type *ResTy = getTypeByID(Record[1]);
1152      const Type *OpTy = getTypeByID(Record[2]);
1153      Value *Op = getFnValueByID(Record[3], OpTy);
1154      if (Opc == -1 || ResTy == 0 || OpTy == 0 || Op == 0)
1155        return Error("Invalid CAST record");
1156      I = CastInst::create((Instruction::CastOps)Opc, Op, ResTy);
1157      break;
1158    }
1159    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n, n x operands]
1160      if (Record.size() < 2 || (Record.size() & 1))
1161        return Error("Invalid GEP record");
1162      const Type *OpTy = getTypeByID(Record[0]);
1163      Value *Op = getFnValueByID(Record[1], OpTy);
1164      if (OpTy == 0 || Op == 0)
1165        return Error("Invalid GEP record");
1166
1167      SmallVector<Value*, 16> GEPIdx;
1168      for (unsigned i = 1, e = Record.size()/2; i != e; ++i) {
1169        const Type *IdxTy = getTypeByID(Record[i*2]);
1170        Value *Idx = getFnValueByID(Record[i*2+1], IdxTy);
1171        if (IdxTy == 0 || Idx == 0)
1172          return Error("Invalid GEP record");
1173        GEPIdx.push_back(Idx);
1174      }
1175
1176      I = new GetElementPtrInst(Op, &GEPIdx[0], GEPIdx.size());
1177      break;
1178    }
1179
1180    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [ty, opval, opval, opval]
1181      if (Record.size() < 4) return Error("Invalid SELECT record");
1182      const Type *Ty = getTypeByID(Record[0]);
1183      Value *Cond = getFnValueByID(Record[1], Type::Int1Ty);
1184      Value *LHS = getFnValueByID(Record[2], Ty);
1185      Value *RHS = getFnValueByID(Record[3], Ty);
1186      if (Ty == 0 || Cond == 0 || LHS == 0 || RHS == 0)
1187        return Error("Invalid SELECT record");
1188      I = new SelectInst(Cond, LHS, RHS);
1189      break;
1190    }
1191
1192    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1193      if (Record.size() < 3) return Error("Invalid EXTRACTELT record");
1194      const Type *OpTy = getTypeByID(Record[0]);
1195      Value *Vec = getFnValueByID(Record[1], OpTy);
1196      Value *Idx = getFnValueByID(Record[2], Type::Int32Ty);
1197      if (OpTy == 0 || Vec == 0 || Idx == 0)
1198        return Error("Invalid EXTRACTELT record");
1199      I = new ExtractElementInst(Vec, Idx);
1200      break;
1201    }
1202
1203    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1204      if (Record.size() < 4) return Error("Invalid INSERTELT record");
1205      const VectorType *OpTy =
1206        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1207      if (OpTy == 0) return Error("Invalid INSERTELT record");
1208      Value *Vec = getFnValueByID(Record[1], OpTy);
1209      Value *Elt = getFnValueByID(Record[2], OpTy->getElementType());
1210      Value *Idx = getFnValueByID(Record[3], Type::Int32Ty);
1211      if (Vec == 0 || Elt == 0 || Idx == 0)
1212        return Error("Invalid INSERTELT record");
1213      I = new InsertElementInst(Vec, Elt, Idx);
1214      break;
1215    }
1216
1217    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [ty,opval,opval,opval]
1218      if (Record.size() < 4) return Error("Invalid SHUFFLEVEC record");
1219      const VectorType *OpTy =
1220        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1221      if (OpTy == 0) return Error("Invalid SHUFFLEVEC record");
1222      Value *Vec1 = getFnValueByID(Record[1], OpTy);
1223      Value *Vec2 = getFnValueByID(Record[2], OpTy);
1224      Value *Mask = getFnValueByID(Record[3],
1225                                   VectorType::get(Type::Int32Ty,
1226                                                   OpTy->getNumElements()));
1227      if (Vec1 == 0 || Vec2 == 0 || Mask == 0)
1228        return Error("Invalid SHUFFLEVEC record");
1229      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1230      break;
1231    }
1232
1233    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1234      if (Record.size() < 4) return Error("Invalid CMP record");
1235      const Type *OpTy = getTypeByID(Record[0]);
1236      Value *LHS = getFnValueByID(Record[1], OpTy);
1237      Value *RHS = getFnValueByID(Record[2], OpTy);
1238      if (OpTy == 0 || LHS == 0 || RHS == 0)
1239        return Error("Invalid CMP record");
1240      if (OpTy->isFPOrFPVector())
1241        I = new FCmpInst((FCmpInst::Predicate)Record[3], LHS, RHS);
1242      else
1243        I = new ICmpInst((ICmpInst::Predicate)Record[3], LHS, RHS);
1244      break;
1245    }
1246
1247    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1248      if (Record.size() == 0) {
1249        I = new ReturnInst();
1250        break;
1251      }
1252      if (Record.size() == 2) {
1253        const Type *OpTy = getTypeByID(Record[0]);
1254        Value *Op = getFnValueByID(Record[1], OpTy);
1255        if (!OpTy || !Op)
1256          return Error("Invalid RET record");
1257        I = new ReturnInst(Op);
1258        break;
1259      }
1260      return Error("Invalid RET record");
1261    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1262      if (Record.size() != 1 && Record.size() != 3)
1263        return Error("Invalid BR record");
1264      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1265      if (TrueDest == 0)
1266        return Error("Invalid BR record");
1267
1268      if (Record.size() == 1)
1269        I = new BranchInst(TrueDest);
1270      else {
1271        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1272        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1273        if (FalseDest == 0 || Cond == 0)
1274          return Error("Invalid BR record");
1275        I = new BranchInst(TrueDest, FalseDest, Cond);
1276      }
1277      break;
1278    }
1279    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1280      if (Record.size() < 3 || (Record.size() & 1) == 0)
1281        return Error("Invalid SWITCH record");
1282      const Type *OpTy = getTypeByID(Record[0]);
1283      Value *Cond = getFnValueByID(Record[1], OpTy);
1284      BasicBlock *Default = getBasicBlock(Record[2]);
1285      if (OpTy == 0 || Cond == 0 || Default == 0)
1286        return Error("Invalid SWITCH record");
1287      unsigned NumCases = (Record.size()-3)/2;
1288      SwitchInst *SI = new SwitchInst(Cond, Default, NumCases);
1289      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1290        ConstantInt *CaseVal =
1291          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1292        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1293        if (CaseVal == 0 || DestBB == 0) {
1294          delete SI;
1295          return Error("Invalid SWITCH record!");
1296        }
1297        SI->addCase(CaseVal, DestBB);
1298      }
1299      I = SI;
1300      break;
1301    }
1302
1303    case bitc::FUNC_CODE_INST_INVOKE: { // INVOKE: [cc,fnty, op0,op1,op2, ...]
1304      if (Record.size() < 5)
1305        return Error("Invalid INVOKE record");
1306      unsigned CCInfo = Record[0];
1307      const PointerType *CalleeTy =
1308        dyn_cast_or_null<PointerType>(getTypeByID(Record[1]));
1309      Value *Callee = getFnValueByID(Record[2], CalleeTy);
1310      BasicBlock *NormalBB = getBasicBlock(Record[3]);
1311      BasicBlock *UnwindBB = getBasicBlock(Record[4]);
1312      if (CalleeTy == 0 || Callee == 0 || NormalBB == 0 || UnwindBB == 0)
1313        return Error("Invalid INVOKE record");
1314
1315      const FunctionType *FTy =
1316        dyn_cast<FunctionType>(CalleeTy->getElementType());
1317
1318      // Check that the right number of fixed parameters are here.
1319      if (FTy == 0 || Record.size() < 5+FTy->getNumParams())
1320        return Error("Invalid INVOKE record");
1321
1322      SmallVector<Value*, 16> Ops;
1323      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1324        Ops.push_back(getFnValueByID(Record[5+i], FTy->getParamType(i)));
1325        if (Ops.back() == 0)
1326          return Error("Invalid INVOKE record");
1327      }
1328
1329      unsigned FirstVarargParam = 5+FTy->getNumParams();
1330      if (FTy->isVarArg()) {
1331        // Read type/value pairs for varargs params.
1332        if ((Record.size()-FirstVarargParam) & 1)
1333          return Error("Invalid INVOKE record");
1334
1335        for (unsigned i = FirstVarargParam, e = Record.size(); i != e; i += 2) {
1336          const Type *ArgTy = getTypeByID(Record[i]);
1337          Ops.push_back(getFnValueByID(Record[i+1], ArgTy));
1338          if (Ops.back() == 0 || ArgTy == 0)
1339            return Error("Invalid INVOKE record");
1340        }
1341      } else {
1342        if (Record.size() != FirstVarargParam)
1343          return Error("Invalid INVOKE record");
1344      }
1345
1346      I = new InvokeInst(Callee, NormalBB, UnwindBB, &Ops[0], Ops.size());
1347      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1348      break;
1349    }
1350    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1351      I = new UnwindInst();
1352      break;
1353    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1354      I = new UnreachableInst();
1355      break;
1356    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, #ops, val0,bb0, ...]
1357      if (Record.size() < 2 || Record.size() < 2+Record[1] || (Record[1]&1))
1358        return Error("Invalid PHI record");
1359      const Type *Ty = getTypeByID(Record[0]);
1360      if (!Ty) return Error("Invalid PHI record");
1361
1362      PHINode *PN = new PHINode(Ty);
1363      PN->reserveOperandSpace(Record[1]);
1364
1365      for (unsigned i = 0, e = Record[1]; i != e; i += 2) {
1366        Value *V = getFnValueByID(Record[2+i], Ty);
1367        BasicBlock *BB = getBasicBlock(Record[3+i]);
1368        if (!V || !BB) return Error("Invalid PHI record");
1369        PN->addIncoming(V, BB);
1370      }
1371      I = PN;
1372      break;
1373    }
1374
1375    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1376      if (Record.size() < 3)
1377        return Error("Invalid MALLOC record");
1378      const PointerType *Ty =
1379        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1380      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1381      unsigned Align = Record[2];
1382      if (!Ty || !Size) return Error("Invalid MALLOC record");
1383      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1384      break;
1385    }
1386    case bitc::FUNC_CODE_INST_FREE: { // FREE: [opty, op]
1387      if (Record.size() < 2)
1388        return Error("Invalid FREE record");
1389      const Type *OpTy = getTypeByID(Record[0]);
1390      Value *Op = getFnValueByID(Record[1], OpTy);
1391      if (!OpTy || !Op)
1392        return Error("Invalid FREE record");
1393      I = new FreeInst(Op);
1394      break;
1395    }
1396    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1397      if (Record.size() < 3)
1398        return Error("Invalid ALLOCA record");
1399      const PointerType *Ty =
1400        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1401      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1402      unsigned Align = Record[2];
1403      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1404      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1405      break;
1406    }
1407    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1408      if (Record.size() < 4)
1409        return Error("Invalid LOAD record");
1410      const Type *OpTy = getTypeByID(Record[0]);
1411      Value *Op = getFnValueByID(Record[1], OpTy);
1412      if (!OpTy || !Op)
1413        return Error("Invalid LOAD record");
1414      I = new LoadInst(Op, "", Record[3], (1 << Record[2]) >> 1);
1415      break;
1416    }
1417    case bitc::FUNC_CODE_INST_STORE: { // STORE:[ptrty,val,ptr, align, vol]
1418      if (Record.size() < 5)
1419        return Error("Invalid LOAD record");
1420      const PointerType *OpTy =
1421        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1422      Value *Op = getFnValueByID(Record[1], OpTy ? OpTy->getElementType() : 0);
1423      Value *Ptr = getFnValueByID(Record[2], OpTy);
1424      if (!OpTy || !Op || !Ptr)
1425        return Error("Invalid STORE record");
1426      I = new StoreInst(Op, Ptr, Record[4], (1 << Record[3]) >> 1);
1427      break;
1428    }
1429    case bitc::FUNC_CODE_INST_CALL: { // CALL: [cc, fnty, fnid, arg0, arg1...]
1430      if (Record.size() < 3)
1431        return Error("Invalid CALL record");
1432      unsigned CCInfo = Record[0];
1433      const PointerType *OpTy =
1434        dyn_cast_or_null<PointerType>(getTypeByID(Record[1]));
1435      const FunctionType *FTy = 0;
1436      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1437      Value *Callee = getFnValueByID(Record[2], OpTy);
1438      if (!FTy || !Callee || Record.size() < FTy->getNumParams()+3)
1439        return Error("Invalid CALL record");
1440
1441      SmallVector<Value*, 16> Args;
1442      // Read the fixed params.
1443      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1444        Args.push_back(getFnValueByID(Record[i+3], FTy->getParamType(i)));
1445        if (Args.back() == 0) return Error("Invalid CALL record");
1446      }
1447
1448
1449      // Read type/value pairs for varargs params.
1450      unsigned NextArg = FTy->getNumParams()+3;
1451      if (!FTy->isVarArg()) {
1452        if (NextArg != Record.size())
1453          return Error("Invalid CALL record");
1454      } else {
1455        if ((Record.size()-NextArg) & 1)
1456          return Error("Invalid CALL record");
1457        for (unsigned e = Record.size(); NextArg != e; NextArg += 2) {
1458          Args.push_back(getFnValueByID(Record[NextArg+1],
1459                                        getTypeByID(Record[NextArg])));
1460          if (Args.back() == 0) return Error("Invalid CALL record");
1461        }
1462      }
1463
1464      I = new CallInst(Callee, &Args[0], Args.size());
1465      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1466      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1467      break;
1468    }
1469    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1470      if (Record.size() < 3)
1471        return Error("Invalid VAARG record");
1472      const Type *OpTy = getTypeByID(Record[0]);
1473      Value *Op = getFnValueByID(Record[1], OpTy);
1474      const Type *ResTy = getTypeByID(Record[2]);
1475      if (!OpTy || !Op || !ResTy)
1476        return Error("Invalid VAARG record");
1477      I = new VAArgInst(Op, ResTy);
1478      break;
1479    }
1480    }
1481
1482    // Add instruction to end of current BB.  If there is no current BB, reject
1483    // this file.
1484    if (CurBB == 0) {
1485      delete I;
1486      return Error("Invalid instruction with no BB");
1487    }
1488    CurBB->getInstList().push_back(I);
1489
1490    // If this was a terminator instruction, move to the next block.
1491    if (isa<TerminatorInst>(I)) {
1492      ++CurBBNo;
1493      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1494    }
1495
1496    // Non-void values get registered in the value table for future use.
1497    if (I && I->getType() != Type::VoidTy)
1498      ValueList.AssignValue(I, NextValueNo++);
1499  }
1500
1501  // Check the function list for unresolved values.
1502  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1503    if (A->getParent() == 0) {
1504      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1505      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1506        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1507          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1508          delete A;
1509        }
1510      }
1511      return Error("Never resolved value found in function!");
1512    }
1513  }
1514
1515  // Trim the value list down to the size it was before we parsed this function.
1516  ValueList.shrinkTo(ModuleValueListSize);
1517  std::vector<BasicBlock*>().swap(FunctionBBs);
1518
1519  return false;
1520}
1521
1522
1523//===----------------------------------------------------------------------===//
1524// External interface
1525//===----------------------------------------------------------------------===//
1526
1527/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1528///
1529ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1530                                               std::string *ErrMsg) {
1531  BitcodeReader *R = new BitcodeReader(Buffer);
1532  if (R->ParseBitcode()) {
1533    if (ErrMsg)
1534      *ErrMsg = R->getErrorString();
1535
1536    // Don't let the BitcodeReader dtor delete 'Buffer'.
1537    R->releaseMemoryBuffer();
1538    delete R;
1539    return 0;
1540  }
1541  return R;
1542}
1543
1544/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
1545/// If an error occurs, return null and fill in *ErrMsg if non-null.
1546Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
1547  BitcodeReader *R;
1548  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
1549  if (!R) return 0;
1550
1551  // Read the whole module, get a pointer to it, tell ModuleProvider not to
1552  // delete it when its dtor is run.
1553  Module *M = R->releaseModule(ErrMsg);
1554
1555  // Don't let the BitcodeReader dtor delete 'Buffer'.
1556  R->releaseMemoryBuffer();
1557  delete R;
1558  return M;
1559}
1560