BitcodeReader.cpp revision 76520191abf157dfa2bcb473406193ab362480b6 
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/ADT/SmallString.h"
21#include "llvm/Support/MathExtras.h"
22#include "llvm/Support/MemoryBuffer.h"
23using namespace llvm;
24
25BitcodeReader::~BitcodeReader() {
26  delete Buffer;
27}
28
29
30/// ConvertToString - Convert a string from a record into an std::string, return
31/// true on failure.
32template<typename StrTy>
33static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
34                            StrTy &Result) {
35  if (Record.size() < Idx+1 || Record.size() < Record[Idx]+Idx+1)
36    return true;
37
38  for (unsigned i = 0, e = Record[Idx]; i != e; ++i)
39    Result += (char)Record[Idx+i+1];
40  return false;
41}
42
43static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
44  switch (Val) {
45  default: // Map unknown/new linkages to external
46  case 0: return GlobalValue::ExternalLinkage;
47  case 1: return GlobalValue::WeakLinkage;
48  case 2: return GlobalValue::AppendingLinkage;
49  case 3: return GlobalValue::InternalLinkage;
50  case 4: return GlobalValue::LinkOnceLinkage;
51  case 5: return GlobalValue::DLLImportLinkage;
52  case 6: return GlobalValue::DLLExportLinkage;
53  case 7: return GlobalValue::ExternalWeakLinkage;
54  }
55}
56
57static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
58  switch (Val) {
59  default: // Map unknown visibilities to default.
60  case 0: return GlobalValue::DefaultVisibility;
61  case 1: return GlobalValue::HiddenVisibility;
62  case 2: return GlobalValue::ProtectedVisibility;
63  }
64}
65
66static int GetDecodedCastOpcode(unsigned Val) {
67  switch (Val) {
68  default: return -1;
69  case bitc::CAST_TRUNC   : return Instruction::Trunc;
70  case bitc::CAST_ZEXT    : return Instruction::ZExt;
71  case bitc::CAST_SEXT    : return Instruction::SExt;
72  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
73  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
74  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
75  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
76  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
77  case bitc::CAST_FPEXT   : return Instruction::FPExt;
78  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
79  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
80  case bitc::CAST_BITCAST : return Instruction::BitCast;
81  }
82}
83static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
84  switch (Val) {
85  default: return -1;
86  case bitc::BINOP_ADD:  return Instruction::Add;
87  case bitc::BINOP_SUB:  return Instruction::Sub;
88  case bitc::BINOP_MUL:  return Instruction::Mul;
89  case bitc::BINOP_UDIV: return Instruction::UDiv;
90  case bitc::BINOP_SDIV:
91    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
92  case bitc::BINOP_UREM: return Instruction::URem;
93  case bitc::BINOP_SREM:
94    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
95  case bitc::BINOP_SHL:  return Instruction::Shl;
96  case bitc::BINOP_LSHR: return Instruction::LShr;
97  case bitc::BINOP_ASHR: return Instruction::AShr;
98  case bitc::BINOP_AND:  return Instruction::And;
99  case bitc::BINOP_OR:   return Instruction::Or;
100  case bitc::BINOP_XOR:  return Instruction::Xor;
101  }
102}
103
104
105namespace {
106  /// @brief A class for maintaining the slot number definition
107  /// as a placeholder for the actual definition for forward constants defs.
108  class ConstantPlaceHolder : public ConstantExpr {
109    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
110    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
111  public:
112    Use Op;
113    ConstantPlaceHolder(const Type *Ty)
114      : ConstantExpr(Ty, Instruction::UserOp1, &Op, 1),
115        Op(UndefValue::get(Type::Int32Ty), this) {
116    }
117  };
118}
119
120Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
121                                                    const Type *Ty) {
122  if (Idx >= size()) {
123    // Insert a bunch of null values.
124    Uses.resize(Idx+1);
125    OperandList = &Uses[0];
126    NumOperands = Idx+1;
127  }
128
129  if (Value *V = Uses[Idx]) {
130    assert(Ty == V->getType() && "Type mismatch in constant table!");
131    return cast<Constant>(V);
132  }
133
134  // Create and return a placeholder, which will later be RAUW'd.
135  Constant *C = new ConstantPlaceHolder(Ty);
136  Uses[Idx].init(C, this);
137  return C;
138}
139
140Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
141  if (Idx >= size()) {
142    // Insert a bunch of null values.
143    Uses.resize(Idx+1);
144    OperandList = &Uses[0];
145    NumOperands = Idx+1;
146  }
147
148  if (Value *V = Uses[Idx]) {
149    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
150    return V;
151  }
152
153  // No type specified, must be invalid reference.
154  if (Ty == 0) return 0;
155
156  // Create and return a placeholder, which will later be RAUW'd.
157  Value *V = new Argument(Ty);
158  Uses[Idx].init(V, this);
159  return V;
160}
161
162
163const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
164  // If the TypeID is in range, return it.
165  if (ID < TypeList.size())
166    return TypeList[ID].get();
167  if (!isTypeTable) return 0;
168
169  // The type table allows forward references.  Push as many Opaque types as
170  // needed to get up to ID.
171  while (TypeList.size() <= ID)
172    TypeList.push_back(OpaqueType::get());
173  return TypeList.back().get();
174}
175
176bool BitcodeReader::ParseTypeTable() {
177  if (Stream.EnterSubBlock())
178    return Error("Malformed block record");
179
180  if (!TypeList.empty())
181    return Error("Multiple TYPE_BLOCKs found!");
182
183  SmallVector<uint64_t, 64> Record;
184  unsigned NumRecords = 0;
185
186  // Read all the records for this type table.
187  while (1) {
188    unsigned Code = Stream.ReadCode();
189    if (Code == bitc::END_BLOCK) {
190      if (NumRecords != TypeList.size())
191        return Error("Invalid type forward reference in TYPE_BLOCK");
192      if (Stream.ReadBlockEnd())
193        return Error("Error at end of type table block");
194      return false;
195    }
196
197    if (Code == bitc::ENTER_SUBBLOCK) {
198      // No known subblocks, always skip them.
199      Stream.ReadSubBlockID();
200      if (Stream.SkipBlock())
201        return Error("Malformed block record");
202      continue;
203    }
204
205    if (Code == bitc::DEFINE_ABBREV) {
206      Stream.ReadAbbrevRecord();
207      continue;
208    }
209
210    // Read a record.
211    Record.clear();
212    const Type *ResultTy = 0;
213    switch (Stream.ReadRecord(Code, Record)) {
214    default:  // Default behavior: unknown type.
215      ResultTy = 0;
216      break;
217    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
218      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
219      // type list.  This allows us to reserve space.
220      if (Record.size() < 1)
221        return Error("Invalid TYPE_CODE_NUMENTRY record");
222      TypeList.reserve(Record[0]);
223      continue;
224    case bitc::TYPE_CODE_META:      // TYPE_CODE_META: [metacode]...
225      // No metadata supported yet.
226      if (Record.size() < 1)
227        return Error("Invalid TYPE_CODE_META record");
228      continue;
229
230    case bitc::TYPE_CODE_VOID:      // VOID
231      ResultTy = Type::VoidTy;
232      break;
233    case bitc::TYPE_CODE_FLOAT:     // FLOAT
234      ResultTy = Type::FloatTy;
235      break;
236    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
237      ResultTy = Type::DoubleTy;
238      break;
239    case bitc::TYPE_CODE_LABEL:     // LABEL
240      ResultTy = Type::LabelTy;
241      break;
242    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
243      ResultTy = 0;
244      break;
245    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
246      if (Record.size() < 1)
247        return Error("Invalid Integer type record");
248
249      ResultTy = IntegerType::get(Record[0]);
250      break;
251    case bitc::TYPE_CODE_POINTER:   // POINTER: [pointee type]
252      if (Record.size() < 1)
253        return Error("Invalid POINTER type record");
254      ResultTy = PointerType::get(getTypeByID(Record[0], true));
255      break;
256    case bitc::TYPE_CODE_FUNCTION: {
257      // FUNCTION: [vararg, retty, #pararms, paramty N]
258      if (Record.size() < 3 || Record.size() < Record[2]+3)
259        return Error("Invalid FUNCTION type record");
260      std::vector<const Type*> ArgTys;
261      for (unsigned i = 0, e = Record[2]; i != e; ++i)
262        ArgTys.push_back(getTypeByID(Record[3+i], true));
263
264      // FIXME: PARAM TYS.
265      ResultTy = FunctionType::get(getTypeByID(Record[1], true), ArgTys,
266                                   Record[0]);
267      break;
268    }
269    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, #elts, eltty x N]
270      if (Record.size() < 2 || Record.size() < Record[1]+2)
271        return Error("Invalid STRUCT type record");
272      std::vector<const Type*> EltTys;
273      for (unsigned i = 0, e = Record[1]; i != e; ++i)
274        EltTys.push_back(getTypeByID(Record[2+i], true));
275      ResultTy = StructType::get(EltTys, Record[0]);
276      break;
277    }
278    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
279      if (Record.size() < 2)
280        return Error("Invalid ARRAY type record");
281      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
282      break;
283    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
284      if (Record.size() < 2)
285        return Error("Invalid VECTOR type record");
286      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
287      break;
288    }
289
290    if (NumRecords == TypeList.size()) {
291      // If this is a new type slot, just append it.
292      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
293      ++NumRecords;
294    } else if (ResultTy == 0) {
295      // Otherwise, this was forward referenced, so an opaque type was created,
296      // but the result type is actually just an opaque.  Leave the one we
297      // created previously.
298      ++NumRecords;
299    } else {
300      // Otherwise, this was forward referenced, so an opaque type was created.
301      // Resolve the opaque type to the real type now.
302      assert(NumRecords < TypeList.size() && "Typelist imbalance");
303      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
304
305      // Don't directly push the new type on the Tab. Instead we want to replace
306      // the opaque type we previously inserted with the new concrete value. The
307      // refinement from the abstract (opaque) type to the new type causes all
308      // uses of the abstract type to use the concrete type (NewTy). This will
309      // also cause the opaque type to be deleted.
310      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
311
312      // This should have replaced the old opaque type with the new type in the
313      // value table... or with a preexisting type that was already in the
314      // system.  Let's just make sure it did.
315      assert(TypeList[NumRecords-1].get() != OldTy &&
316             "refineAbstractType didn't work!");
317    }
318  }
319}
320
321
322bool BitcodeReader::ParseTypeSymbolTable() {
323  if (Stream.EnterSubBlock())
324    return Error("Malformed block record");
325
326  SmallVector<uint64_t, 64> Record;
327
328  // Read all the records for this type table.
329  std::string TypeName;
330  while (1) {
331    unsigned Code = Stream.ReadCode();
332    if (Code == bitc::END_BLOCK) {
333      if (Stream.ReadBlockEnd())
334        return Error("Error at end of type symbol table block");
335      return false;
336    }
337
338    if (Code == bitc::ENTER_SUBBLOCK) {
339      // No known subblocks, always skip them.
340      Stream.ReadSubBlockID();
341      if (Stream.SkipBlock())
342        return Error("Malformed block record");
343      continue;
344    }
345
346    if (Code == bitc::DEFINE_ABBREV) {
347      Stream.ReadAbbrevRecord();
348      continue;
349    }
350
351    // Read a record.
352    Record.clear();
353    switch (Stream.ReadRecord(Code, Record)) {
354    default:  // Default behavior: unknown type.
355      break;
356    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namelen, namechar x N]
357      if (ConvertToString(Record, 1, TypeName))
358        return Error("Invalid TST_ENTRY record");
359      unsigned TypeID = Record[0];
360      if (TypeID >= TypeList.size())
361        return Error("Invalid Type ID in TST_ENTRY record");
362
363      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
364      TypeName.clear();
365      break;
366    }
367  }
368}
369
370bool BitcodeReader::ParseValueSymbolTable() {
371  if (Stream.EnterSubBlock())
372    return Error("Malformed block record");
373
374  SmallVector<uint64_t, 64> Record;
375
376  // Read all the records for this value table.
377  SmallString<128> ValueName;
378  while (1) {
379    unsigned Code = Stream.ReadCode();
380    if (Code == bitc::END_BLOCK) {
381      if (Stream.ReadBlockEnd())
382        return Error("Error at end of value symbol table block");
383      return false;
384    }
385    if (Code == bitc::ENTER_SUBBLOCK) {
386      // No known subblocks, always skip them.
387      Stream.ReadSubBlockID();
388      if (Stream.SkipBlock())
389        return Error("Malformed block record");
390      continue;
391    }
392
393    if (Code == bitc::DEFINE_ABBREV) {
394      Stream.ReadAbbrevRecord();
395      continue;
396    }
397
398    // Read a record.
399    Record.clear();
400    switch (Stream.ReadRecord(Code, Record)) {
401    default:  // Default behavior: unknown type.
402      break;
403    case bitc::VST_CODE_ENTRY:    // VST_ENTRY: [valueid, namelen, namechar x N]
404      if (ConvertToString(Record, 1, ValueName))
405        return Error("Invalid TST_ENTRY record");
406      unsigned ValueID = Record[0];
407      if (ValueID >= ValueList.size())
408        return Error("Invalid Value ID in VST_ENTRY record");
409      Value *V = ValueList[ValueID];
410
411      V->setName(&ValueName[0], ValueName.size());
412      ValueName.clear();
413      break;
414    case bitc::VST_CODE_BBENTRY:
415      if (ConvertToString(Record, 1, ValueName))
416        return Error("Invalid VST_BBENTRY record");
417      BasicBlock *BB = getBasicBlock(Record[0]);
418      if (BB == 0)
419        return Error("Invalid BB ID in VST_BBENTRY record");
420
421      BB->setName(&ValueName[0], ValueName.size());
422      ValueName.clear();
423      break;
424    }
425  }
426}
427
428/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
429/// the LSB for dense VBR encoding.
430static uint64_t DecodeSignRotatedValue(uint64_t V) {
431  if ((V & 1) == 0)
432    return V >> 1;
433  if (V != 1)
434    return -(V >> 1);
435  // There is no such thing as -0 with integers.  "-0" really means MININT.
436  return 1ULL << 63;
437}
438
439/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
440/// values and aliases that we can.
441bool BitcodeReader::ResolveGlobalAndAliasInits() {
442  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
443  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
444
445  GlobalInitWorklist.swap(GlobalInits);
446  AliasInitWorklist.swap(AliasInits);
447
448  while (!GlobalInitWorklist.empty()) {
449    unsigned ValID = GlobalInitWorklist.back().second;
450    if (ValID >= ValueList.size()) {
451      // Not ready to resolve this yet, it requires something later in the file.
452      GlobalInits.push_back(GlobalInitWorklist.back());
453    } else {
454      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
455        GlobalInitWorklist.back().first->setInitializer(C);
456      else
457        return Error("Global variable initializer is not a constant!");
458    }
459    GlobalInitWorklist.pop_back();
460  }
461
462  while (!AliasInitWorklist.empty()) {
463    unsigned ValID = AliasInitWorklist.back().second;
464    if (ValID >= ValueList.size()) {
465      AliasInits.push_back(AliasInitWorklist.back());
466    } else {
467      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
468        AliasInitWorklist.back().first->setAliasee(C);
469      else
470        return Error("Alias initializer is not a constant!");
471    }
472    AliasInitWorklist.pop_back();
473  }
474  return false;
475}
476
477
478bool BitcodeReader::ParseConstants() {
479  if (Stream.EnterSubBlock())
480    return Error("Malformed block record");
481
482  SmallVector<uint64_t, 64> Record;
483
484  // Read all the records for this value table.
485  const Type *CurTy = Type::Int32Ty;
486  unsigned NextCstNo = ValueList.size();
487  while (1) {
488    unsigned Code = Stream.ReadCode();
489    if (Code == bitc::END_BLOCK) {
490      if (NextCstNo != ValueList.size())
491        return Error("Invalid constant reference!");
492
493      if (Stream.ReadBlockEnd())
494        return Error("Error at end of constants block");
495      return false;
496    }
497
498    if (Code == bitc::ENTER_SUBBLOCK) {
499      // No known subblocks, always skip them.
500      Stream.ReadSubBlockID();
501      if (Stream.SkipBlock())
502        return Error("Malformed block record");
503      continue;
504    }
505
506    if (Code == bitc::DEFINE_ABBREV) {
507      Stream.ReadAbbrevRecord();
508      continue;
509    }
510
511    // Read a record.
512    Record.clear();
513    Value *V = 0;
514    switch (Stream.ReadRecord(Code, Record)) {
515    default:  // Default behavior: unknown constant
516    case bitc::CST_CODE_UNDEF:     // UNDEF
517      V = UndefValue::get(CurTy);
518      break;
519    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
520      if (Record.empty())
521        return Error("Malformed CST_SETTYPE record");
522      if (Record[0] >= TypeList.size())
523        return Error("Invalid Type ID in CST_SETTYPE record");
524      CurTy = TypeList[Record[0]];
525      continue;  // Skip the ValueList manipulation.
526    case bitc::CST_CODE_NULL:      // NULL
527      V = Constant::getNullValue(CurTy);
528      break;
529    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
530      if (!isa<IntegerType>(CurTy) || Record.empty())
531        return Error("Invalid CST_INTEGER record");
532      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
533      break;
534    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n, n x intval]
535      if (!isa<IntegerType>(CurTy) || Record.empty() ||
536          Record.size() < Record[0]+1)
537        return Error("Invalid WIDE_INTEGER record");
538
539      unsigned NumWords = Record[0];
540      SmallVector<uint64_t, 8> Words;
541      Words.resize(NumWords);
542      for (unsigned i = 0; i != NumWords; ++i)
543        Words[i] = DecodeSignRotatedValue(Record[i+1]);
544      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
545                                 NumWords, &Words[0]));
546      break;
547    }
548    case bitc::CST_CODE_FLOAT:     // FLOAT: [fpval]
549      if (Record.empty())
550        return Error("Invalid FLOAT record");
551      if (CurTy == Type::FloatTy)
552        V = ConstantFP::get(CurTy, BitsToFloat(Record[0]));
553      else if (CurTy == Type::DoubleTy)
554        V = ConstantFP::get(CurTy, BitsToDouble(Record[0]));
555      else
556        V = UndefValue::get(CurTy);
557      break;
558
559    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n, n x value number]
560      if (Record.empty() || Record.size() < Record[0]+1)
561        return Error("Invalid CST_AGGREGATE record");
562
563      unsigned Size = Record[0];
564      std::vector<Constant*> Elts;
565
566      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
567        for (unsigned i = 0; i != Size; ++i)
568          Elts.push_back(ValueList.getConstantFwdRef(Record[i+1],
569                                                     STy->getElementType(i)));
570        V = ConstantStruct::get(STy, Elts);
571      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
572        const Type *EltTy = ATy->getElementType();
573        for (unsigned i = 0; i != Size; ++i)
574          Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], EltTy));
575        V = ConstantArray::get(ATy, Elts);
576      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
577        const Type *EltTy = VTy->getElementType();
578        for (unsigned i = 0; i != Size; ++i)
579          Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], EltTy));
580        V = ConstantVector::get(Elts);
581      } else {
582        V = UndefValue::get(CurTy);
583      }
584      break;
585    }
586
587    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
588      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
589      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
590      if (Opc < 0) {
591        V = UndefValue::get(CurTy);  // Unknown binop.
592      } else {
593        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
594        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
595        V = ConstantExpr::get(Opc, LHS, RHS);
596      }
597      break;
598    }
599    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
600      if (Record.size() < 3) return Error("Invalid CE_CAST record");
601      int Opc = GetDecodedCastOpcode(Record[0]);
602      if (Opc < 0) {
603        V = UndefValue::get(CurTy);  // Unknown cast.
604      } else {
605        const Type *OpTy = getTypeByID(Record[1]);
606        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
607        V = ConstantExpr::getCast(Opc, Op, CurTy);
608      }
609      break;
610    }
611    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
612      if ((Record.size() & 1) == 0) return Error("Invalid CE_GEP record");
613      SmallVector<Constant*, 16> Elts;
614      for (unsigned i = 1, e = Record.size(); i != e; i += 2) {
615        const Type *ElTy = getTypeByID(Record[i]);
616        if (!ElTy) return Error("Invalid CE_GEP record");
617        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
618      }
619      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
620      break;
621    }
622    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
623      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
624      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
625                                                              Type::Int1Ty),
626                                  ValueList.getConstantFwdRef(Record[1],CurTy),
627                                  ValueList.getConstantFwdRef(Record[2],CurTy));
628      break;
629    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
630      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
631      const VectorType *OpTy =
632        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
633      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
634      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
635      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
636                                                  OpTy->getElementType());
637      V = ConstantExpr::getExtractElement(Op0, Op1);
638      break;
639    }
640    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
641      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
642      if (Record.size() < 3 || OpTy == 0)
643        return Error("Invalid CE_INSERTELT record");
644      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
645      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
646                                                  OpTy->getElementType());
647      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
648      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
649      break;
650    }
651    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
652      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
653      if (Record.size() < 3 || OpTy == 0)
654        return Error("Invalid CE_INSERTELT record");
655      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
656      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
657      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
658      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
659      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
660      break;
661    }
662    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
663      if (Record.size() < 4) return Error("Invalid CE_CMP record");
664      const Type *OpTy = getTypeByID(Record[0]);
665      if (OpTy == 0) return Error("Invalid CE_CMP record");
666      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
667      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
668
669      if (OpTy->isFloatingPoint())
670        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
671      else
672        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
673      break;
674    }
675    }
676
677    ValueList.AssignValue(V, NextCstNo);
678    ++NextCstNo;
679  }
680}
681
682/// RememberAndSkipFunctionBody - When we see the block for a function body,
683/// remember where it is and then skip it.  This lets us lazily deserialize the
684/// functions.
685bool BitcodeReader::RememberAndSkipFunctionBody() {
686  // Get the function we are talking about.
687  if (FunctionsWithBodies.empty())
688    return Error("Insufficient function protos");
689
690  Function *Fn = FunctionsWithBodies.back();
691  FunctionsWithBodies.pop_back();
692
693  // Save the current stream state.
694  uint64_t CurBit = Stream.GetCurrentBitNo();
695  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
696
697  // Set the functions linkage to GhostLinkage so we know it is lazily
698  // deserialized.
699  Fn->setLinkage(GlobalValue::GhostLinkage);
700
701  // Skip over the function block for now.
702  if (Stream.SkipBlock())
703    return Error("Malformed block record");
704  return false;
705}
706
707bool BitcodeReader::ParseModule(const std::string &ModuleID) {
708  // Reject multiple MODULE_BLOCK's in a single bitstream.
709  if (TheModule)
710    return Error("Multiple MODULE_BLOCKs in same stream");
711
712  if (Stream.EnterSubBlock())
713    return Error("Malformed block record");
714
715  // Otherwise, create the module.
716  TheModule = new Module(ModuleID);
717
718  SmallVector<uint64_t, 64> Record;
719  std::vector<std::string> SectionTable;
720
721  // Read all the records for this module.
722  while (!Stream.AtEndOfStream()) {
723    unsigned Code = Stream.ReadCode();
724    if (Code == bitc::END_BLOCK) {
725      if (Stream.ReadBlockEnd())
726        return Error("Error at end of module block");
727
728      // Patch the initializers for globals and aliases up.
729      ResolveGlobalAndAliasInits();
730      if (!GlobalInits.empty() || !AliasInits.empty())
731        return Error("Malformed global initializer set");
732      if (!FunctionsWithBodies.empty())
733        return Error("Too few function bodies found");
734
735      // Force deallocation of memory for these vectors to favor the client that
736      // want lazy deserialization.
737      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
738      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
739      std::vector<Function*>().swap(FunctionsWithBodies);
740      return false;
741    }
742
743    if (Code == bitc::ENTER_SUBBLOCK) {
744      switch (Stream.ReadSubBlockID()) {
745      default:  // Skip unknown content.
746        if (Stream.SkipBlock())
747          return Error("Malformed block record");
748        break;
749      case bitc::TYPE_BLOCK_ID:
750        if (ParseTypeTable())
751          return true;
752        break;
753      case bitc::TYPE_SYMTAB_BLOCK_ID:
754        if (ParseTypeSymbolTable())
755          return true;
756        break;
757      case bitc::VALUE_SYMTAB_BLOCK_ID:
758        if (ParseValueSymbolTable())
759          return true;
760        break;
761      case bitc::CONSTANTS_BLOCK_ID:
762        if (ParseConstants() || ResolveGlobalAndAliasInits())
763          return true;
764        break;
765      case bitc::FUNCTION_BLOCK_ID:
766        // If this is the first function body we've seen, reverse the
767        // FunctionsWithBodies list.
768        if (!HasReversedFunctionsWithBodies) {
769          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
770          HasReversedFunctionsWithBodies = true;
771        }
772
773        if (RememberAndSkipFunctionBody())
774          return true;
775        break;
776      }
777      continue;
778    }
779
780    if (Code == bitc::DEFINE_ABBREV) {
781      Stream.ReadAbbrevRecord();
782      continue;
783    }
784
785    // Read a record.
786    switch (Stream.ReadRecord(Code, Record)) {
787    default: break;  // Default behavior, ignore unknown content.
788    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
789      if (Record.size() < 1)
790        return Error("Malformed MODULE_CODE_VERSION");
791      // Only version #0 is supported so far.
792      if (Record[0] != 0)
793        return Error("Unknown bitstream version!");
794      break;
795    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strlen, strchr x N]
796      std::string S;
797      if (ConvertToString(Record, 0, S))
798        return Error("Invalid MODULE_CODE_TRIPLE record");
799      TheModule->setTargetTriple(S);
800      break;
801    }
802    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strlen, strchr x N]
803      std::string S;
804      if (ConvertToString(Record, 0, S))
805        return Error("Invalid MODULE_CODE_DATALAYOUT record");
806      TheModule->setDataLayout(S);
807      break;
808    }
809    case bitc::MODULE_CODE_ASM: {  // ASM: [strlen, strchr x N]
810      std::string S;
811      if (ConvertToString(Record, 0, S))
812        return Error("Invalid MODULE_CODE_ASM record");
813      TheModule->setModuleInlineAsm(S);
814      break;
815    }
816    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strlen, strchr x N]
817      std::string S;
818      if (ConvertToString(Record, 0, S))
819        return Error("Invalid MODULE_CODE_DEPLIB record");
820      TheModule->addLibrary(S);
821      break;
822    }
823    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strlen, strchr x N]
824      std::string S;
825      if (ConvertToString(Record, 0, S))
826        return Error("Invalid MODULE_CODE_SECTIONNAME record");
827      SectionTable.push_back(S);
828      break;
829    }
830    // GLOBALVAR: [type, isconst, initid,
831    //             linkage, alignment, section, visibility, threadlocal]
832    case bitc::MODULE_CODE_GLOBALVAR: {
833      if (Record.size() < 6)
834        return Error("Invalid MODULE_CODE_GLOBALVAR record");
835      const Type *Ty = getTypeByID(Record[0]);
836      if (!isa<PointerType>(Ty))
837        return Error("Global not a pointer type!");
838      Ty = cast<PointerType>(Ty)->getElementType();
839
840      bool isConstant = Record[1];
841      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
842      unsigned Alignment = (1 << Record[4]) >> 1;
843      std::string Section;
844      if (Record[5]) {
845        if (Record[5]-1 >= SectionTable.size())
846          return Error("Invalid section ID");
847        Section = SectionTable[Record[5]-1];
848      }
849      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
850      if (Record.size() >= 6) Visibility = GetDecodedVisibility(Record[6]);
851      bool isThreadLocal = false;
852      if (Record.size() >= 7) isThreadLocal = Record[7];
853
854      GlobalVariable *NewGV =
855        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule);
856      NewGV->setAlignment(Alignment);
857      if (!Section.empty())
858        NewGV->setSection(Section);
859      NewGV->setVisibility(Visibility);
860      NewGV->setThreadLocal(isThreadLocal);
861
862      ValueList.push_back(NewGV);
863
864      // Remember which value to use for the global initializer.
865      if (unsigned InitID = Record[2])
866        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
867      break;
868    }
869    // FUNCTION:  [type, callingconv, isproto, linkage, alignment, section,
870    //             visibility]
871    case bitc::MODULE_CODE_FUNCTION: {
872      if (Record.size() < 7)
873        return Error("Invalid MODULE_CODE_FUNCTION record");
874      const Type *Ty = getTypeByID(Record[0]);
875      if (!isa<PointerType>(Ty))
876        return Error("Function not a pointer type!");
877      const FunctionType *FTy =
878        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
879      if (!FTy)
880        return Error("Function not a pointer to function type!");
881
882      Function *Func = new Function(FTy, GlobalValue::ExternalLinkage,
883                                    "", TheModule);
884
885      Func->setCallingConv(Record[1]);
886      bool isProto = Record[2];
887      Func->setLinkage(GetDecodedLinkage(Record[3]));
888      Func->setAlignment((1 << Record[4]) >> 1);
889      if (Record[5]) {
890        if (Record[5]-1 >= SectionTable.size())
891          return Error("Invalid section ID");
892        Func->setSection(SectionTable[Record[5]-1]);
893      }
894      Func->setVisibility(GetDecodedVisibility(Record[6]));
895
896      ValueList.push_back(Func);
897
898      // If this is a function with a body, remember the prototype we are
899      // creating now, so that we can match up the body with them later.
900      if (!isProto)
901        FunctionsWithBodies.push_back(Func);
902      break;
903    }
904    // ALIAS: [alias type, aliasee val#, linkage]
905    case bitc::MODULE_CODE_ALIAS: {
906      if (Record.size() < 3)
907        return Error("Invalid MODULE_ALIAS record");
908      const Type *Ty = getTypeByID(Record[0]);
909      if (!isa<PointerType>(Ty))
910        return Error("Function not a pointer type!");
911
912      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
913                                           "", 0, TheModule);
914      ValueList.push_back(NewGA);
915      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
916      break;
917    }
918    /// MODULE_CODE_PURGEVALS: [numvals]
919    case bitc::MODULE_CODE_PURGEVALS:
920      // Trim down the value list to the specified size.
921      if (Record.size() < 1 || Record[0] > ValueList.size())
922        return Error("Invalid MODULE_PURGEVALS record");
923      ValueList.shrinkTo(Record[0]);
924      break;
925    }
926    Record.clear();
927  }
928
929  return Error("Premature end of bitstream");
930}
931
932
933bool BitcodeReader::ParseBitcode() {
934  TheModule = 0;
935
936  if (Buffer->getBufferSize() & 3)
937    return Error("Bitcode stream should be a multiple of 4 bytes in length");
938
939  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
940  Stream.init(BufPtr, BufPtr+Buffer->getBufferSize());
941
942  // Sniff for the signature.
943  if (Stream.Read(8) != 'B' ||
944      Stream.Read(8) != 'C' ||
945      Stream.Read(4) != 0x0 ||
946      Stream.Read(4) != 0xC ||
947      Stream.Read(4) != 0xE ||
948      Stream.Read(4) != 0xD)
949    return Error("Invalid bitcode signature");
950
951  // We expect a number of well-defined blocks, though we don't necessarily
952  // need to understand them all.
953  while (!Stream.AtEndOfStream()) {
954    unsigned Code = Stream.ReadCode();
955
956    if (Code != bitc::ENTER_SUBBLOCK)
957      return Error("Invalid record at top-level");
958
959    unsigned BlockID = Stream.ReadSubBlockID();
960
961    // We only know the MODULE subblock ID.
962    if (BlockID == bitc::MODULE_BLOCK_ID) {
963      if (ParseModule(Buffer->getBufferIdentifier()))
964        return true;
965    } else if (Stream.SkipBlock()) {
966      return Error("Malformed block record");
967    }
968  }
969
970  return false;
971}
972
973
974bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
975  // If it already is material, ignore the request.
976  if (!F->hasNotBeenReadFromBytecode()) return false;
977
978  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
979    DeferredFunctionInfo.find(F);
980  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
981
982  // Move the bit stream to the saved position of the deferred function body and
983  // restore the real linkage type for the function.
984  Stream.JumpToBit(DFII->second.first);
985  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
986  DeferredFunctionInfo.erase(DFII);
987
988  if (ParseFunctionBody(F)) {
989    if (ErrInfo) *ErrInfo = ErrorString;
990    return true;
991  }
992
993  return false;
994}
995
996Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
997  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
998    DeferredFunctionInfo.begin();
999  while (!DeferredFunctionInfo.empty()) {
1000    Function *F = (*I++).first;
1001    assert(F->hasNotBeenReadFromBytecode() &&
1002           "Deserialized function found in map!");
1003    if (materializeFunction(F, ErrInfo))
1004      return 0;
1005  }
1006  return TheModule;
1007}
1008
1009
1010/// ParseFunctionBody - Lazily parse the specified function body block.
1011bool BitcodeReader::ParseFunctionBody(Function *F) {
1012  if (Stream.EnterSubBlock())
1013    return Error("Malformed block record");
1014
1015  unsigned ModuleValueListSize = ValueList.size();
1016
1017  // Add all the function arguments to the value table.
1018  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1019    ValueList.push_back(I);
1020
1021  unsigned NextValueNo = ValueList.size();
1022  BasicBlock *CurBB = 0;
1023  unsigned CurBBNo = 0;
1024
1025  // Read all the records.
1026  SmallVector<uint64_t, 64> Record;
1027  while (1) {
1028    unsigned Code = Stream.ReadCode();
1029    if (Code == bitc::END_BLOCK) {
1030      if (Stream.ReadBlockEnd())
1031        return Error("Error at end of function block");
1032      break;
1033    }
1034
1035    if (Code == bitc::ENTER_SUBBLOCK) {
1036      switch (Stream.ReadSubBlockID()) {
1037      default:  // Skip unknown content.
1038        if (Stream.SkipBlock())
1039          return Error("Malformed block record");
1040        break;
1041      case bitc::CONSTANTS_BLOCK_ID:
1042        if (ParseConstants()) return true;
1043        NextValueNo = ValueList.size();
1044        break;
1045      case bitc::VALUE_SYMTAB_BLOCK_ID:
1046        if (ParseValueSymbolTable()) return true;
1047        break;
1048      }
1049      continue;
1050    }
1051
1052    if (Code == bitc::DEFINE_ABBREV) {
1053      Stream.ReadAbbrevRecord();
1054      continue;
1055    }
1056
1057    // Read a record.
1058    Record.clear();
1059    Instruction *I = 0;
1060    switch (Stream.ReadRecord(Code, Record)) {
1061    default: // Default behavior: reject
1062      return Error("Unknown instruction");
1063    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1064      if (Record.size() < 1 || Record[0] == 0)
1065        return Error("Invalid DECLAREBLOCKS record");
1066      // Create all the basic blocks for the function.
1067      FunctionBBs.resize(Record[0]);
1068      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1069        FunctionBBs[i] = new BasicBlock("", F);
1070      CurBB = FunctionBBs[0];
1071      continue;
1072
1073    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opcode, ty, opval, opval]
1074      if (Record.size() < 4) return Error("Invalid BINOP record");
1075      const Type *Ty = getTypeByID(Record[1]);
1076      int Opc = GetDecodedBinaryOpcode(Record[0], Ty);
1077      Value *LHS = getFnValueByID(Record[2], Ty);
1078      Value *RHS = getFnValueByID(Record[3], Ty);
1079      if (Opc == -1 || Ty == 0 || LHS == 0 || RHS == 0)
1080         return Error("Invalid BINOP record");
1081      I = BinaryOperator::create((Instruction::BinaryOps)Opc, LHS, RHS);
1082      break;
1083    }
1084    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opcode, ty, opty, opval]
1085      if (Record.size() < 4) return Error("Invalid CAST record");
1086      int Opc = GetDecodedCastOpcode(Record[0]);
1087      const Type *ResTy = getTypeByID(Record[1]);
1088      const Type *OpTy = getTypeByID(Record[2]);
1089      Value *Op = getFnValueByID(Record[3], OpTy);
1090      if (Opc == -1 || ResTy == 0 || OpTy == 0 || Op == 0)
1091        return Error("Invalid CAST record");
1092      I = CastInst::create((Instruction::CastOps)Opc, Op, ResTy);
1093      break;
1094    }
1095    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n, n x operands]
1096      if (Record.size() < 2 || (Record.size() & 1))
1097        return Error("Invalid GEP record");
1098      const Type *OpTy = getTypeByID(Record[0]);
1099      Value *Op = getFnValueByID(Record[1], OpTy);
1100      if (OpTy == 0 || Op == 0)
1101        return Error("Invalid GEP record");
1102
1103      SmallVector<Value*, 16> GEPIdx;
1104      for (unsigned i = 1, e = Record.size()/2; i != e; ++i) {
1105        const Type *IdxTy = getTypeByID(Record[i*2]);
1106        Value *Idx = getFnValueByID(Record[i*2+1], IdxTy);
1107        if (IdxTy == 0 || Idx == 0)
1108          return Error("Invalid GEP record");
1109        GEPIdx.push_back(Idx);
1110      }
1111
1112      I = new GetElementPtrInst(Op, &GEPIdx[0], GEPIdx.size());
1113      break;
1114    }
1115
1116    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [ty, opval, opval, opval]
1117      if (Record.size() < 4) return Error("Invalid SELECT record");
1118      const Type *Ty = getTypeByID(Record[0]);
1119      Value *Cond = getFnValueByID(Record[1], Type::Int1Ty);
1120      Value *LHS = getFnValueByID(Record[2], Ty);
1121      Value *RHS = getFnValueByID(Record[3], Ty);
1122      if (Ty == 0 || Cond == 0 || LHS == 0 || RHS == 0)
1123        return Error("Invalid SELECT record");
1124      I = new SelectInst(Cond, LHS, RHS);
1125      break;
1126    }
1127
1128    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1129      if (Record.size() < 3) return Error("Invalid EXTRACTELT record");
1130      const Type *OpTy = getTypeByID(Record[0]);
1131      Value *Vec = getFnValueByID(Record[1], OpTy);
1132      Value *Idx = getFnValueByID(Record[2], Type::Int32Ty);
1133      if (OpTy == 0 || Vec == 0 || Idx == 0)
1134        return Error("Invalid EXTRACTELT record");
1135      I = new ExtractElementInst(Vec, Idx);
1136      break;
1137    }
1138
1139    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1140      if (Record.size() < 4) return Error("Invalid INSERTELT record");
1141      const VectorType *OpTy =
1142        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1143      if (OpTy == 0) return Error("Invalid INSERTELT record");
1144      Value *Vec = getFnValueByID(Record[1], OpTy);
1145      Value *Elt = getFnValueByID(Record[2], OpTy->getElementType());
1146      Value *Idx = getFnValueByID(Record[3], Type::Int32Ty);
1147      if (Vec == 0 || Elt == 0 || Idx == 0)
1148        return Error("Invalid INSERTELT record");
1149      I = new InsertElementInst(Vec, Elt, Idx);
1150      break;
1151    }
1152
1153    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [ty,opval,opval,opval]
1154      if (Record.size() < 4) return Error("Invalid SHUFFLEVEC record");
1155      const VectorType *OpTy =
1156        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1157      if (OpTy == 0) return Error("Invalid SHUFFLEVEC record");
1158      Value *Vec1 = getFnValueByID(Record[1], OpTy);
1159      Value *Vec2 = getFnValueByID(Record[2], OpTy);
1160      Value *Mask = getFnValueByID(Record[3],
1161                                   VectorType::get(Type::Int32Ty,
1162                                                   OpTy->getNumElements()));
1163      if (Vec1 == 0 || Vec2 == 0 || Mask == 0)
1164        return Error("Invalid SHUFFLEVEC record");
1165      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1166      break;
1167    }
1168
1169    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1170      if (Record.size() < 4) return Error("Invalid CMP record");
1171      const Type *OpTy = getTypeByID(Record[0]);
1172      Value *LHS = getFnValueByID(Record[1], OpTy);
1173      Value *RHS = getFnValueByID(Record[2], OpTy);
1174      if (OpTy == 0 || LHS == 0 || RHS == 0)
1175        return Error("Invalid CMP record");
1176      if (OpTy->isFPOrFPVector())
1177        I = new FCmpInst((FCmpInst::Predicate)Record[3], LHS, RHS);
1178      else
1179        I = new ICmpInst((ICmpInst::Predicate)Record[3], LHS, RHS);
1180      break;
1181    }
1182
1183    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1184      if (Record.size() == 0) {
1185        I = new ReturnInst();
1186        break;
1187      }
1188      if (Record.size() == 2) {
1189        const Type *OpTy = getTypeByID(Record[0]);
1190        Value *Op = getFnValueByID(Record[1], OpTy);
1191        if (!OpTy || !Op)
1192          return Error("Invalid RET record");
1193        I = new ReturnInst(Op);
1194        break;
1195      }
1196      return Error("Invalid RET record");
1197    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1198      if (Record.size() != 1 && Record.size() != 3)
1199        return Error("Invalid BR record");
1200      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1201      if (TrueDest == 0)
1202        return Error("Invalid BR record");
1203
1204      if (Record.size() == 1)
1205        I = new BranchInst(TrueDest);
1206      else {
1207        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1208        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1209        if (FalseDest == 0 || Cond == 0)
1210          return Error("Invalid BR record");
1211        I = new BranchInst(TrueDest, FalseDest, Cond);
1212      }
1213      break;
1214    }
1215    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1216      if (Record.size() < 3 || (Record.size() & 1) == 0)
1217        return Error("Invalid SWITCH record");
1218      const Type *OpTy = getTypeByID(Record[0]);
1219      Value *Cond = getFnValueByID(Record[1], OpTy);
1220      BasicBlock *Default = getBasicBlock(Record[2]);
1221      if (OpTy == 0 || Cond == 0 || Default == 0)
1222        return Error("Invalid SWITCH record");
1223      unsigned NumCases = (Record.size()-3)/2;
1224      SwitchInst *SI = new SwitchInst(Cond, Default, NumCases);
1225      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1226        ConstantInt *CaseVal =
1227          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1228        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1229        if (CaseVal == 0 || DestBB == 0) {
1230          delete SI;
1231          return Error("Invalid SWITCH record!");
1232        }
1233        SI->addCase(CaseVal, DestBB);
1234      }
1235      I = SI;
1236      break;
1237    }
1238
1239    case bitc::FUNC_CODE_INST_INVOKE: { // INVOKE: [cc,fnty, op0,op1,op2, ...]
1240      if (Record.size() < 5)
1241        return Error("Invalid INVOKE record");
1242      unsigned CCInfo = Record[0];
1243      const PointerType *CalleeTy =
1244        dyn_cast_or_null<PointerType>(getTypeByID(Record[1]));
1245      Value *Callee = getFnValueByID(Record[2], CalleeTy);
1246      BasicBlock *NormalBB = getBasicBlock(Record[3]);
1247      BasicBlock *UnwindBB = getBasicBlock(Record[4]);
1248      if (CalleeTy == 0 || Callee == 0 || NormalBB == 0 || UnwindBB == 0)
1249        return Error("Invalid INVOKE record");
1250
1251      const FunctionType *FTy =
1252        dyn_cast<FunctionType>(CalleeTy->getElementType());
1253
1254      // Check that the right number of fixed parameters are here.
1255      if (FTy == 0 || Record.size() < 5+FTy->getNumParams())
1256        return Error("Invalid INVOKE record");
1257
1258      SmallVector<Value*, 16> Ops;
1259      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1260        Ops.push_back(getFnValueByID(Record[5+i], FTy->getParamType(i)));
1261        if (Ops.back() == 0)
1262          return Error("Invalid INVOKE record");
1263      }
1264
1265      unsigned FirstVarargParam = 5+FTy->getNumParams();
1266      if (FTy->isVarArg()) {
1267        // Read type/value pairs for varargs params.
1268        if ((Record.size()-FirstVarargParam) & 1)
1269          return Error("Invalid INVOKE record");
1270
1271        for (unsigned i = FirstVarargParam, e = Record.size(); i != e; i += 2) {
1272          const Type *ArgTy = getTypeByID(Record[i]);
1273          Ops.push_back(getFnValueByID(Record[i+1], ArgTy));
1274          if (Ops.back() == 0 || ArgTy == 0)
1275            return Error("Invalid INVOKE record");
1276        }
1277      } else {
1278        if (Record.size() != FirstVarargParam)
1279          return Error("Invalid INVOKE record");
1280      }
1281
1282      I = new InvokeInst(Callee, NormalBB, UnwindBB, &Ops[0], Ops.size());
1283      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1284      break;
1285    }
1286    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1287      I = new UnwindInst();
1288      break;
1289    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1290      I = new UnreachableInst();
1291      break;
1292    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, #ops, val0,bb0, ...]
1293      if (Record.size() < 2 || Record.size() < 2+Record[1] || (Record[1]&1))
1294        return Error("Invalid PHI record");
1295      const Type *Ty = getTypeByID(Record[0]);
1296      if (!Ty) return Error("Invalid PHI record");
1297
1298      PHINode *PN = new PHINode(Ty);
1299      PN->reserveOperandSpace(Record[1]);
1300
1301      for (unsigned i = 0, e = Record[1]; i != e; i += 2) {
1302        Value *V = getFnValueByID(Record[2+i], Ty);
1303        BasicBlock *BB = getBasicBlock(Record[3+i]);
1304        if (!V || !BB) return Error("Invalid PHI record");
1305        PN->addIncoming(V, BB);
1306      }
1307      I = PN;
1308      break;
1309    }
1310
1311    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1312      if (Record.size() < 3)
1313        return Error("Invalid MALLOC record");
1314      const PointerType *Ty =
1315        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1316      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1317      unsigned Align = Record[2];
1318      if (!Ty || !Size) return Error("Invalid MALLOC record");
1319      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1320      break;
1321    }
1322    case bitc::FUNC_CODE_INST_FREE: { // FREE: [opty, op]
1323      if (Record.size() < 2)
1324        return Error("Invalid FREE record");
1325      const Type *OpTy = getTypeByID(Record[0]);
1326      Value *Op = getFnValueByID(Record[1], OpTy);
1327      if (!OpTy || !Op)
1328        return Error("Invalid FREE record");
1329      I = new FreeInst(Op);
1330      break;
1331    }
1332    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1333      if (Record.size() < 3)
1334        return Error("Invalid ALLOCA record");
1335      const PointerType *Ty =
1336        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1337      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1338      unsigned Align = Record[2];
1339      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1340      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1341      break;
1342    }
1343    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1344      if (Record.size() < 4)
1345        return Error("Invalid LOAD record");
1346      const Type *OpTy = getTypeByID(Record[0]);
1347      Value *Op = getFnValueByID(Record[1], OpTy);
1348      if (!OpTy || !Op)
1349        return Error("Invalid LOAD record");
1350      I = new LoadInst(Op, "", Record[3], (1 << Record[2]) >> 1);
1351      break;
1352    }
1353    case bitc::FUNC_CODE_INST_STORE: { // STORE:[ptrty,val,ptr, align, vol]
1354      if (Record.size() < 5)
1355        return Error("Invalid LOAD record");
1356      const PointerType *OpTy =
1357        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1358      Value *Op = getFnValueByID(Record[1], OpTy ? OpTy->getElementType() : 0);
1359      Value *Ptr = getFnValueByID(Record[2], OpTy);
1360      if (!OpTy || !Op || !Ptr)
1361        return Error("Invalid STORE record");
1362      I = new StoreInst(Op, Ptr, (1 << Record[3]) >> 1, Record[4]);
1363      break;
1364    }
1365    case bitc::FUNC_CODE_INST_CALL: { // CALL: [cc, fnty, fnid, arg0, arg1...]
1366      if (Record.size() < 3)
1367        return Error("Invalid CALL record");
1368      unsigned CCInfo = Record[0];
1369      const PointerType *OpTy =
1370        dyn_cast_or_null<PointerType>(getTypeByID(Record[1]));
1371      const FunctionType *FTy = 0;
1372      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1373      Value *Callee = getFnValueByID(Record[2], OpTy);
1374      if (!FTy || !Callee || Record.size() < FTy->getNumParams()+3)
1375        return Error("Invalid CALL record");
1376
1377      SmallVector<Value*, 16> Args;
1378      // Read the fixed params.
1379      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1380        Args.push_back(getFnValueByID(Record[i+3], FTy->getParamType(i)));
1381        if (Args.back() == 0) return Error("Invalid CALL record");
1382      }
1383
1384
1385      // Read type/value pairs for varargs params.
1386      unsigned NextArg = FTy->getNumParams()+3;
1387      if (!FTy->isVarArg()) {
1388        if (NextArg != Record.size())
1389          return Error("Invalid CALL record");
1390      } else {
1391        if ((Record.size()-NextArg) & 1)
1392          return Error("Invalid CALL record");
1393        for (unsigned e = Record.size(); NextArg != e; NextArg += 2) {
1394          Args.push_back(getFnValueByID(Record[NextArg+1],
1395                                        getTypeByID(Record[NextArg])));
1396          if (Args.back() == 0) return Error("Invalid CALL record");
1397        }
1398      }
1399
1400      I = new CallInst(Callee, &Args[0], Args.size());
1401      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1402      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1403      break;
1404    }
1405    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1406      if (Record.size() < 3)
1407        return Error("Invalid VAARG record");
1408      const Type *OpTy = getTypeByID(Record[0]);
1409      Value *Op = getFnValueByID(Record[1], OpTy);
1410      const Type *ResTy = getTypeByID(Record[2]);
1411      if (!OpTy || !Op || !ResTy)
1412        return Error("Invalid VAARG record");
1413      I = new VAArgInst(Op, ResTy);
1414      break;
1415    }
1416    }
1417
1418    // Add instruction to end of current BB.  If there is no current BB, reject
1419    // this file.
1420    if (CurBB == 0) {
1421      delete I;
1422      return Error("Invalid instruction with no BB");
1423    }
1424    CurBB->getInstList().push_back(I);
1425
1426    // If this was a terminator instruction, move to the next block.
1427    if (isa<TerminatorInst>(I)) {
1428      ++CurBBNo;
1429      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1430    }
1431
1432    // Non-void values get registered in the value table for future use.
1433    if (I && I->getType() != Type::VoidTy)
1434      ValueList.AssignValue(I, NextValueNo++);
1435  }
1436
1437  // Check the function list for unresolved values.
1438  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1439    if (A->getParent() == 0) {
1440      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1441      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1442        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1443          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1444          delete A;
1445        }
1446      }
1447    }
1448    return Error("Never resolved value found in function!");
1449  }
1450
1451  // Trim the value list down to the size it was before we parsed this function.
1452  ValueList.shrinkTo(ModuleValueListSize);
1453  std::vector<BasicBlock*>().swap(FunctionBBs);
1454
1455  return false;
1456}
1457
1458
1459//===----------------------------------------------------------------------===//
1460// External interface
1461//===----------------------------------------------------------------------===//
1462
1463/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1464///
1465ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1466                                               std::string *ErrMsg) {
1467  BitcodeReader *R = new BitcodeReader(Buffer);
1468  if (R->ParseBitcode()) {
1469    if (ErrMsg)
1470      *ErrMsg = R->getErrorString();
1471
1472    // Don't let the BitcodeReader dtor delete 'Buffer'.
1473    R->releaseMemoryBuffer();
1474    delete R;
1475    return 0;
1476  }
1477  return R;
1478}
1479
1480/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
1481/// If an error occurs, return null and fill in *ErrMsg if non-null.
1482Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
1483  BitcodeReader *R;
1484  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
1485  if (!R) return 0;
1486
1487  // Read the whole module, get a pointer to it, tell ModuleProvider not to
1488  // delete it when its dtor is run.
1489  Module *M = R->releaseModule(ErrMsg);
1490
1491  // Don't let the BitcodeReader dtor delete 'Buffer'.
1492  R->releaseMemoryBuffer();
1493  delete R;
1494  return M;
1495}
1496