BitcodeReader.cpp revision 6994040a952e5fb27605eb3cf29ed86c4e59cf62 
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/InlineAsm.h"
19#include "llvm/Instructions.h"
20#include "llvm/Module.h"
21#include "llvm/ParameterAttributes.h"
22#include "llvm/AutoUpgrade.h"
23#include "llvm/ADT/SmallString.h"
24#include "llvm/Support/MathExtras.h"
25#include "llvm/Support/MemoryBuffer.h"
26using namespace llvm;
27
28void BitcodeReader::FreeState() {
29  delete Buffer;
30  Buffer = 0;
31  std::vector<PATypeHolder>().swap(TypeList);
32  ValueList.clear();
33  std::vector<const ParamAttrsList*>().swap(ParamAttrs);
34  std::vector<BasicBlock*>().swap(FunctionBBs);
35  std::vector<Function*>().swap(FunctionsWithBodies);
36  DeferredFunctionInfo.clear();
37}
38
39//===----------------------------------------------------------------------===//
40//  Helper functions to implement forward reference resolution, etc.
41//===----------------------------------------------------------------------===//
42
43/// ConvertToString - Convert a string from a record into an std::string, return
44/// true on failure.
45template<typename StrTy>
46static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
47                            StrTy &Result) {
48  if (Idx > Record.size())
49    return true;
50
51  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
52    Result += (char)Record[i];
53  return false;
54}
55
56static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
57  switch (Val) {
58  default: // Map unknown/new linkages to external
59  case 0: return GlobalValue::ExternalLinkage;
60  case 1: return GlobalValue::WeakLinkage;
61  case 2: return GlobalValue::AppendingLinkage;
62  case 3: return GlobalValue::InternalLinkage;
63  case 4: return GlobalValue::LinkOnceLinkage;
64  case 5: return GlobalValue::DLLImportLinkage;
65  case 6: return GlobalValue::DLLExportLinkage;
66  case 7: return GlobalValue::ExternalWeakLinkage;
67  }
68}
69
70static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
71  switch (Val) {
72  default: // Map unknown visibilities to default.
73  case 0: return GlobalValue::DefaultVisibility;
74  case 1: return GlobalValue::HiddenVisibility;
75  case 2: return GlobalValue::ProtectedVisibility;
76  }
77}
78
79static int GetDecodedCastOpcode(unsigned Val) {
80  switch (Val) {
81  default: return -1;
82  case bitc::CAST_TRUNC   : return Instruction::Trunc;
83  case bitc::CAST_ZEXT    : return Instruction::ZExt;
84  case bitc::CAST_SEXT    : return Instruction::SExt;
85  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
86  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
87  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
88  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
89  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
90  case bitc::CAST_FPEXT   : return Instruction::FPExt;
91  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
92  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
93  case bitc::CAST_BITCAST : return Instruction::BitCast;
94  }
95}
96static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
97  switch (Val) {
98  default: return -1;
99  case bitc::BINOP_ADD:  return Instruction::Add;
100  case bitc::BINOP_SUB:  return Instruction::Sub;
101  case bitc::BINOP_MUL:  return Instruction::Mul;
102  case bitc::BINOP_UDIV: return Instruction::UDiv;
103  case bitc::BINOP_SDIV:
104    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
105  case bitc::BINOP_UREM: return Instruction::URem;
106  case bitc::BINOP_SREM:
107    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
108  case bitc::BINOP_SHL:  return Instruction::Shl;
109  case bitc::BINOP_LSHR: return Instruction::LShr;
110  case bitc::BINOP_ASHR: return Instruction::AShr;
111  case bitc::BINOP_AND:  return Instruction::And;
112  case bitc::BINOP_OR:   return Instruction::Or;
113  case bitc::BINOP_XOR:  return Instruction::Xor;
114  }
115}
116
117
118namespace {
119  /// @brief A class for maintaining the slot number definition
120  /// as a placeholder for the actual definition for forward constants defs.
121  class ConstantPlaceHolder : public ConstantExpr {
122    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
123    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
124  public:
125    Use Op;
126    ConstantPlaceHolder(const Type *Ty)
127      : ConstantExpr(Ty, Instruction::UserOp1, &Op, 1),
128        Op(UndefValue::get(Type::Int32Ty), this) {
129    }
130  };
131}
132
133Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
134                                                    const Type *Ty) {
135  if (Idx >= size()) {
136    // Insert a bunch of null values.
137    Uses.resize(Idx+1);
138    OperandList = &Uses[0];
139    NumOperands = Idx+1;
140  }
141
142  if (Value *V = Uses[Idx]) {
143    assert(Ty == V->getType() && "Type mismatch in constant table!");
144    return cast<Constant>(V);
145  }
146
147  // Create and return a placeholder, which will later be RAUW'd.
148  Constant *C = new ConstantPlaceHolder(Ty);
149  Uses[Idx].init(C, this);
150  return C;
151}
152
153Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
154  if (Idx >= size()) {
155    // Insert a bunch of null values.
156    Uses.resize(Idx+1);
157    OperandList = &Uses[0];
158    NumOperands = Idx+1;
159  }
160
161  if (Value *V = Uses[Idx]) {
162    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
163    return V;
164  }
165
166  // No type specified, must be invalid reference.
167  if (Ty == 0) return 0;
168
169  // Create and return a placeholder, which will later be RAUW'd.
170  Value *V = new Argument(Ty);
171  Uses[Idx].init(V, this);
172  return V;
173}
174
175
176const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
177  // If the TypeID is in range, return it.
178  if (ID < TypeList.size())
179    return TypeList[ID].get();
180  if (!isTypeTable) return 0;
181
182  // The type table allows forward references.  Push as many Opaque types as
183  // needed to get up to ID.
184  while (TypeList.size() <= ID)
185    TypeList.push_back(OpaqueType::get());
186  return TypeList.back().get();
187}
188
189//===----------------------------------------------------------------------===//
190//  Functions for parsing blocks from the bitcode file
191//===----------------------------------------------------------------------===//
192
193bool BitcodeReader::ParseParamAttrBlock() {
194  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
195    return Error("Malformed block record");
196
197  if (!ParamAttrs.empty())
198    return Error("Multiple PARAMATTR blocks found!");
199
200  SmallVector<uint64_t, 64> Record;
201
202  ParamAttrsVector Attrs;
203
204  // Read all the records.
205  while (1) {
206    unsigned Code = Stream.ReadCode();
207    if (Code == bitc::END_BLOCK) {
208      if (Stream.ReadBlockEnd())
209        return Error("Error at end of PARAMATTR block");
210      return false;
211    }
212
213    if (Code == bitc::ENTER_SUBBLOCK) {
214      // No known subblocks, always skip them.
215      Stream.ReadSubBlockID();
216      if (Stream.SkipBlock())
217        return Error("Malformed block record");
218      continue;
219    }
220
221    if (Code == bitc::DEFINE_ABBREV) {
222      Stream.ReadAbbrevRecord();
223      continue;
224    }
225
226    // Read a record.
227    Record.clear();
228    switch (Stream.ReadRecord(Code, Record)) {
229    default:  // Default behavior: ignore.
230      break;
231    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
232      if (Record.size() & 1)
233        return Error("Invalid ENTRY record");
234
235      ParamAttrsWithIndex PAWI;
236      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
237        PAWI.index = Record[i];
238        PAWI.attrs = Record[i+1];
239        Attrs.push_back(PAWI);
240      }
241      ParamAttrs.push_back(ParamAttrsList::get(Attrs));
242      Attrs.clear();
243      break;
244    }
245    }
246  }
247}
248
249
250bool BitcodeReader::ParseTypeTable() {
251  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID))
252    return Error("Malformed block record");
253
254  if (!TypeList.empty())
255    return Error("Multiple TYPE_BLOCKs found!");
256
257  SmallVector<uint64_t, 64> Record;
258  unsigned NumRecords = 0;
259
260  // Read all the records for this type table.
261  while (1) {
262    unsigned Code = Stream.ReadCode();
263    if (Code == bitc::END_BLOCK) {
264      if (NumRecords != TypeList.size())
265        return Error("Invalid type forward reference in TYPE_BLOCK");
266      if (Stream.ReadBlockEnd())
267        return Error("Error at end of type table block");
268      return false;
269    }
270
271    if (Code == bitc::ENTER_SUBBLOCK) {
272      // No known subblocks, always skip them.
273      Stream.ReadSubBlockID();
274      if (Stream.SkipBlock())
275        return Error("Malformed block record");
276      continue;
277    }
278
279    if (Code == bitc::DEFINE_ABBREV) {
280      Stream.ReadAbbrevRecord();
281      continue;
282    }
283
284    // Read a record.
285    Record.clear();
286    const Type *ResultTy = 0;
287    switch (Stream.ReadRecord(Code, Record)) {
288    default:  // Default behavior: unknown type.
289      ResultTy = 0;
290      break;
291    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
292      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
293      // type list.  This allows us to reserve space.
294      if (Record.size() < 1)
295        return Error("Invalid TYPE_CODE_NUMENTRY record");
296      TypeList.reserve(Record[0]);
297      continue;
298    case bitc::TYPE_CODE_VOID:      // VOID
299      ResultTy = Type::VoidTy;
300      break;
301    case bitc::TYPE_CODE_FLOAT:     // FLOAT
302      ResultTy = Type::FloatTy;
303      break;
304    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
305      ResultTy = Type::DoubleTy;
306      break;
307    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
308      ResultTy = Type::X86_FP80Ty;
309      break;
310    case bitc::TYPE_CODE_FP128:     // FP128
311      ResultTy = Type::FP128Ty;
312      break;
313    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
314      ResultTy = Type::PPC_FP128Ty;
315      break;
316    case bitc::TYPE_CODE_LABEL:     // LABEL
317      ResultTy = Type::LabelTy;
318      break;
319    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
320      ResultTy = 0;
321      break;
322    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
323      if (Record.size() < 1)
324        return Error("Invalid Integer type record");
325
326      ResultTy = IntegerType::get(Record[0]);
327      break;
328    case bitc::TYPE_CODE_POINTER:   // POINTER: [pointee type]
329      if (Record.size() < 1)
330        return Error("Invalid POINTER type record");
331      ResultTy = PointerType::get(getTypeByID(Record[0], true));
332      break;
333    case bitc::TYPE_CODE_FUNCTION: {
334      // FUNCTION: [vararg, attrid, retty, paramty x N]
335      if (Record.size() < 3)
336        return Error("Invalid FUNCTION type record");
337      std::vector<const Type*> ArgTys;
338      for (unsigned i = 3, e = Record.size(); i != e; ++i)
339        ArgTys.push_back(getTypeByID(Record[i], true));
340
341      ResultTy = FunctionType::get(getTypeByID(Record[2], true), ArgTys,
342                                   Record[0], getParamAttrs(Record[1]));
343      break;
344    }
345    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, eltty x N]
346      if (Record.size() < 1)
347        return Error("Invalid STRUCT type record");
348      std::vector<const Type*> EltTys;
349      for (unsigned i = 1, e = Record.size(); i != e; ++i)
350        EltTys.push_back(getTypeByID(Record[i], true));
351      ResultTy = StructType::get(EltTys, Record[0]);
352      break;
353    }
354    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
355      if (Record.size() < 2)
356        return Error("Invalid ARRAY type record");
357      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
358      break;
359    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
360      if (Record.size() < 2)
361        return Error("Invalid VECTOR type record");
362      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
363      break;
364    }
365
366    if (NumRecords == TypeList.size()) {
367      // If this is a new type slot, just append it.
368      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
369      ++NumRecords;
370    } else if (ResultTy == 0) {
371      // Otherwise, this was forward referenced, so an opaque type was created,
372      // but the result type is actually just an opaque.  Leave the one we
373      // created previously.
374      ++NumRecords;
375    } else {
376      // Otherwise, this was forward referenced, so an opaque type was created.
377      // Resolve the opaque type to the real type now.
378      assert(NumRecords < TypeList.size() && "Typelist imbalance");
379      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
380
381      // Don't directly push the new type on the Tab. Instead we want to replace
382      // the opaque type we previously inserted with the new concrete value. The
383      // refinement from the abstract (opaque) type to the new type causes all
384      // uses of the abstract type to use the concrete type (NewTy). This will
385      // also cause the opaque type to be deleted.
386      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
387
388      // This should have replaced the old opaque type with the new type in the
389      // value table... or with a preexisting type that was already in the
390      // system.  Let's just make sure it did.
391      assert(TypeList[NumRecords-1].get() != OldTy &&
392             "refineAbstractType didn't work!");
393    }
394  }
395}
396
397
398bool BitcodeReader::ParseTypeSymbolTable() {
399  if (Stream.EnterSubBlock(bitc::TYPE_SYMTAB_BLOCK_ID))
400    return Error("Malformed block record");
401
402  SmallVector<uint64_t, 64> Record;
403
404  // Read all the records for this type table.
405  std::string TypeName;
406  while (1) {
407    unsigned Code = Stream.ReadCode();
408    if (Code == bitc::END_BLOCK) {
409      if (Stream.ReadBlockEnd())
410        return Error("Error at end of type symbol table block");
411      return false;
412    }
413
414    if (Code == bitc::ENTER_SUBBLOCK) {
415      // No known subblocks, always skip them.
416      Stream.ReadSubBlockID();
417      if (Stream.SkipBlock())
418        return Error("Malformed block record");
419      continue;
420    }
421
422    if (Code == bitc::DEFINE_ABBREV) {
423      Stream.ReadAbbrevRecord();
424      continue;
425    }
426
427    // Read a record.
428    Record.clear();
429    switch (Stream.ReadRecord(Code, Record)) {
430    default:  // Default behavior: unknown type.
431      break;
432    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namechar x N]
433      if (ConvertToString(Record, 1, TypeName))
434        return Error("Invalid TST_ENTRY record");
435      unsigned TypeID = Record[0];
436      if (TypeID >= TypeList.size())
437        return Error("Invalid Type ID in TST_ENTRY record");
438
439      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
440      TypeName.clear();
441      break;
442    }
443  }
444}
445
446bool BitcodeReader::ParseValueSymbolTable() {
447  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
448    return Error("Malformed block record");
449
450  SmallVector<uint64_t, 64> Record;
451
452  // Read all the records for this value table.
453  SmallString<128> ValueName;
454  while (1) {
455    unsigned Code = Stream.ReadCode();
456    if (Code == bitc::END_BLOCK) {
457      if (Stream.ReadBlockEnd())
458        return Error("Error at end of value symbol table block");
459      return false;
460    }
461    if (Code == bitc::ENTER_SUBBLOCK) {
462      // No known subblocks, always skip them.
463      Stream.ReadSubBlockID();
464      if (Stream.SkipBlock())
465        return Error("Malformed block record");
466      continue;
467    }
468
469    if (Code == bitc::DEFINE_ABBREV) {
470      Stream.ReadAbbrevRecord();
471      continue;
472    }
473
474    // Read a record.
475    Record.clear();
476    switch (Stream.ReadRecord(Code, Record)) {
477    default:  // Default behavior: unknown type.
478      break;
479    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
480      if (ConvertToString(Record, 1, ValueName))
481        return Error("Invalid TST_ENTRY record");
482      unsigned ValueID = Record[0];
483      if (ValueID >= ValueList.size())
484        return Error("Invalid Value ID in VST_ENTRY record");
485      Value *V = ValueList[ValueID];
486
487      V->setName(&ValueName[0], ValueName.size());
488      ValueName.clear();
489      break;
490    }
491    case bitc::VST_CODE_BBENTRY: {
492      if (ConvertToString(Record, 1, ValueName))
493        return Error("Invalid VST_BBENTRY record");
494      BasicBlock *BB = getBasicBlock(Record[0]);
495      if (BB == 0)
496        return Error("Invalid BB ID in VST_BBENTRY record");
497
498      BB->setName(&ValueName[0], ValueName.size());
499      ValueName.clear();
500      break;
501    }
502    }
503  }
504}
505
506/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
507/// the LSB for dense VBR encoding.
508static uint64_t DecodeSignRotatedValue(uint64_t V) {
509  if ((V & 1) == 0)
510    return V >> 1;
511  if (V != 1)
512    return -(V >> 1);
513  // There is no such thing as -0 with integers.  "-0" really means MININT.
514  return 1ULL << 63;
515}
516
517/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
518/// values and aliases that we can.
519bool BitcodeReader::ResolveGlobalAndAliasInits() {
520  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
521  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
522
523  GlobalInitWorklist.swap(GlobalInits);
524  AliasInitWorklist.swap(AliasInits);
525
526  while (!GlobalInitWorklist.empty()) {
527    unsigned ValID = GlobalInitWorklist.back().second;
528    if (ValID >= ValueList.size()) {
529      // Not ready to resolve this yet, it requires something later in the file.
530      GlobalInits.push_back(GlobalInitWorklist.back());
531    } else {
532      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
533        GlobalInitWorklist.back().first->setInitializer(C);
534      else
535        return Error("Global variable initializer is not a constant!");
536    }
537    GlobalInitWorklist.pop_back();
538  }
539
540  while (!AliasInitWorklist.empty()) {
541    unsigned ValID = AliasInitWorklist.back().second;
542    if (ValID >= ValueList.size()) {
543      AliasInits.push_back(AliasInitWorklist.back());
544    } else {
545      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
546        AliasInitWorklist.back().first->setAliasee(C);
547      else
548        return Error("Alias initializer is not a constant!");
549    }
550    AliasInitWorklist.pop_back();
551  }
552  return false;
553}
554
555
556bool BitcodeReader::ParseConstants() {
557  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
558    return Error("Malformed block record");
559
560  SmallVector<uint64_t, 64> Record;
561
562  // Read all the records for this value table.
563  const Type *CurTy = Type::Int32Ty;
564  unsigned NextCstNo = ValueList.size();
565  while (1) {
566    unsigned Code = Stream.ReadCode();
567    if (Code == bitc::END_BLOCK) {
568      if (NextCstNo != ValueList.size())
569        return Error("Invalid constant reference!");
570
571      if (Stream.ReadBlockEnd())
572        return Error("Error at end of constants block");
573      return false;
574    }
575
576    if (Code == bitc::ENTER_SUBBLOCK) {
577      // No known subblocks, always skip them.
578      Stream.ReadSubBlockID();
579      if (Stream.SkipBlock())
580        return Error("Malformed block record");
581      continue;
582    }
583
584    if (Code == bitc::DEFINE_ABBREV) {
585      Stream.ReadAbbrevRecord();
586      continue;
587    }
588
589    // Read a record.
590    Record.clear();
591    Value *V = 0;
592    switch (Stream.ReadRecord(Code, Record)) {
593    default:  // Default behavior: unknown constant
594    case bitc::CST_CODE_UNDEF:     // UNDEF
595      V = UndefValue::get(CurTy);
596      break;
597    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
598      if (Record.empty())
599        return Error("Malformed CST_SETTYPE record");
600      if (Record[0] >= TypeList.size())
601        return Error("Invalid Type ID in CST_SETTYPE record");
602      CurTy = TypeList[Record[0]];
603      continue;  // Skip the ValueList manipulation.
604    case bitc::CST_CODE_NULL:      // NULL
605      V = Constant::getNullValue(CurTy);
606      break;
607    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
608      if (!isa<IntegerType>(CurTy) || Record.empty())
609        return Error("Invalid CST_INTEGER record");
610      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
611      break;
612    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
613      if (!isa<IntegerType>(CurTy) || Record.empty())
614        return Error("Invalid WIDE_INTEGER record");
615
616      unsigned NumWords = Record.size();
617      SmallVector<uint64_t, 8> Words;
618      Words.resize(NumWords);
619      for (unsigned i = 0; i != NumWords; ++i)
620        Words[i] = DecodeSignRotatedValue(Record[i]);
621      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
622                                 NumWords, &Words[0]));
623      break;
624    }
625    case bitc::CST_CODE_FLOAT:     // FLOAT: [fpval]
626      if (Record.empty())
627        return Error("Invalid FLOAT record");
628      if (CurTy == Type::FloatTy)
629        V = ConstantFP::get(CurTy, BitsToFloat(Record[0]));
630      else if (CurTy == Type::DoubleTy)
631        V = ConstantFP::get(CurTy, BitsToDouble(Record[0]));
632      else
633        V = UndefValue::get(CurTy);
634      break;
635
636    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
637      if (Record.empty())
638        return Error("Invalid CST_AGGREGATE record");
639
640      unsigned Size = Record.size();
641      std::vector<Constant*> Elts;
642
643      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
644        for (unsigned i = 0; i != Size; ++i)
645          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
646                                                     STy->getElementType(i)));
647        V = ConstantStruct::get(STy, Elts);
648      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
649        const Type *EltTy = ATy->getElementType();
650        for (unsigned i = 0; i != Size; ++i)
651          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
652        V = ConstantArray::get(ATy, Elts);
653      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
654        const Type *EltTy = VTy->getElementType();
655        for (unsigned i = 0; i != Size; ++i)
656          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
657        V = ConstantVector::get(Elts);
658      } else {
659        V = UndefValue::get(CurTy);
660      }
661      break;
662    }
663    case bitc::CST_CODE_STRING: { // STRING: [values]
664      if (Record.empty())
665        return Error("Invalid CST_AGGREGATE record");
666
667      const ArrayType *ATy = cast<ArrayType>(CurTy);
668      const Type *EltTy = ATy->getElementType();
669
670      unsigned Size = Record.size();
671      std::vector<Constant*> Elts;
672      for (unsigned i = 0; i != Size; ++i)
673        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
674      V = ConstantArray::get(ATy, Elts);
675      break;
676    }
677    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
678      if (Record.empty())
679        return Error("Invalid CST_AGGREGATE record");
680
681      const ArrayType *ATy = cast<ArrayType>(CurTy);
682      const Type *EltTy = ATy->getElementType();
683
684      unsigned Size = Record.size();
685      std::vector<Constant*> Elts;
686      for (unsigned i = 0; i != Size; ++i)
687        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
688      Elts.push_back(Constant::getNullValue(EltTy));
689      V = ConstantArray::get(ATy, Elts);
690      break;
691    }
692    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
693      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
694      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
695      if (Opc < 0) {
696        V = UndefValue::get(CurTy);  // Unknown binop.
697      } else {
698        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
699        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
700        V = ConstantExpr::get(Opc, LHS, RHS);
701      }
702      break;
703    }
704    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
705      if (Record.size() < 3) return Error("Invalid CE_CAST record");
706      int Opc = GetDecodedCastOpcode(Record[0]);
707      if (Opc < 0) {
708        V = UndefValue::get(CurTy);  // Unknown cast.
709      } else {
710        const Type *OpTy = getTypeByID(Record[1]);
711        if (!OpTy) return Error("Invalid CE_CAST record");
712        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
713        V = ConstantExpr::getCast(Opc, Op, CurTy);
714      }
715      break;
716    }
717    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
718      if (Record.size() & 1) return Error("Invalid CE_GEP record");
719      SmallVector<Constant*, 16> Elts;
720      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
721        const Type *ElTy = getTypeByID(Record[i]);
722        if (!ElTy) return Error("Invalid CE_GEP record");
723        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
724      }
725      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
726      break;
727    }
728    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
729      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
730      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
731                                                              Type::Int1Ty),
732                                  ValueList.getConstantFwdRef(Record[1],CurTy),
733                                  ValueList.getConstantFwdRef(Record[2],CurTy));
734      break;
735    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
736      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
737      const VectorType *OpTy =
738        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
739      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
740      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
741      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
742                                                  OpTy->getElementType());
743      V = ConstantExpr::getExtractElement(Op0, Op1);
744      break;
745    }
746    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
747      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
748      if (Record.size() < 3 || OpTy == 0)
749        return Error("Invalid CE_INSERTELT record");
750      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
751      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
752                                                  OpTy->getElementType());
753      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
754      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
755      break;
756    }
757    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
758      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
759      if (Record.size() < 3 || OpTy == 0)
760        return Error("Invalid CE_INSERTELT record");
761      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
762      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
763      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
764      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
765      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
766      break;
767    }
768    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
769      if (Record.size() < 4) return Error("Invalid CE_CMP record");
770      const Type *OpTy = getTypeByID(Record[0]);
771      if (OpTy == 0) return Error("Invalid CE_CMP record");
772      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
773      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
774
775      if (OpTy->isFloatingPoint())
776        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
777      else
778        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
779      break;
780    }
781    case bitc::CST_CODE_INLINEASM: {
782      if (Record.size() < 2) return Error("Invalid INLINEASM record");
783      std::string AsmStr, ConstrStr;
784      bool HasSideEffects = Record[0];
785      unsigned AsmStrSize = Record[1];
786      if (2+AsmStrSize >= Record.size())
787        return Error("Invalid INLINEASM record");
788      unsigned ConstStrSize = Record[2+AsmStrSize];
789      if (3+AsmStrSize+ConstStrSize > Record.size())
790        return Error("Invalid INLINEASM record");
791
792      for (unsigned i = 0; i != AsmStrSize; ++i)
793        AsmStr += (char)Record[2+i];
794      for (unsigned i = 0; i != ConstStrSize; ++i)
795        ConstrStr += (char)Record[3+AsmStrSize+i];
796      const PointerType *PTy = cast<PointerType>(CurTy);
797      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
798                         AsmStr, ConstrStr, HasSideEffects);
799      break;
800    }
801    }
802
803    ValueList.AssignValue(V, NextCstNo);
804    ++NextCstNo;
805  }
806}
807
808/// RememberAndSkipFunctionBody - When we see the block for a function body,
809/// remember where it is and then skip it.  This lets us lazily deserialize the
810/// functions.
811bool BitcodeReader::RememberAndSkipFunctionBody() {
812  // Get the function we are talking about.
813  if (FunctionsWithBodies.empty())
814    return Error("Insufficient function protos");
815
816  Function *Fn = FunctionsWithBodies.back();
817  FunctionsWithBodies.pop_back();
818
819  // Save the current stream state.
820  uint64_t CurBit = Stream.GetCurrentBitNo();
821  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
822
823  // Set the functions linkage to GhostLinkage so we know it is lazily
824  // deserialized.
825  Fn->setLinkage(GlobalValue::GhostLinkage);
826
827  // Skip over the function block for now.
828  if (Stream.SkipBlock())
829    return Error("Malformed block record");
830  return false;
831}
832
833bool BitcodeReader::ParseModule(const std::string &ModuleID) {
834  // Reject multiple MODULE_BLOCK's in a single bitstream.
835  if (TheModule)
836    return Error("Multiple MODULE_BLOCKs in same stream");
837
838  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
839    return Error("Malformed block record");
840
841  // Otherwise, create the module.
842  TheModule = new Module(ModuleID);
843
844  SmallVector<uint64_t, 64> Record;
845  std::vector<std::string> SectionTable;
846
847  // Read all the records for this module.
848  while (!Stream.AtEndOfStream()) {
849    unsigned Code = Stream.ReadCode();
850    if (Code == bitc::END_BLOCK) {
851      if (Stream.ReadBlockEnd())
852        return Error("Error at end of module block");
853
854      // Patch the initializers for globals and aliases up.
855      ResolveGlobalAndAliasInits();
856      if (!GlobalInits.empty() || !AliasInits.empty())
857        return Error("Malformed global initializer set");
858      if (!FunctionsWithBodies.empty())
859        return Error("Too few function bodies found");
860
861      // Look for intrinsic functions which need to be upgraded at some point
862      for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
863           FI != FE; ++FI) {
864        if (Function* NewFn = UpgradeIntrinsicFunction(FI))
865          UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
866      }
867
868      // Force deallocation of memory for these vectors to favor the client that
869      // want lazy deserialization.
870      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
871      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
872      std::vector<Function*>().swap(FunctionsWithBodies);
873      return false;
874    }
875
876    if (Code == bitc::ENTER_SUBBLOCK) {
877      switch (Stream.ReadSubBlockID()) {
878      default:  // Skip unknown content.
879        if (Stream.SkipBlock())
880          return Error("Malformed block record");
881        break;
882      case bitc::BLOCKINFO_BLOCK_ID:
883        if (Stream.ReadBlockInfoBlock())
884          return Error("Malformed BlockInfoBlock");
885        break;
886      case bitc::PARAMATTR_BLOCK_ID:
887        if (ParseParamAttrBlock())
888          return true;
889        break;
890      case bitc::TYPE_BLOCK_ID:
891        if (ParseTypeTable())
892          return true;
893        break;
894      case bitc::TYPE_SYMTAB_BLOCK_ID:
895        if (ParseTypeSymbolTable())
896          return true;
897        break;
898      case bitc::VALUE_SYMTAB_BLOCK_ID:
899        if (ParseValueSymbolTable())
900          return true;
901        break;
902      case bitc::CONSTANTS_BLOCK_ID:
903        if (ParseConstants() || ResolveGlobalAndAliasInits())
904          return true;
905        break;
906      case bitc::FUNCTION_BLOCK_ID:
907        // If this is the first function body we've seen, reverse the
908        // FunctionsWithBodies list.
909        if (!HasReversedFunctionsWithBodies) {
910          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
911          HasReversedFunctionsWithBodies = true;
912        }
913
914        if (RememberAndSkipFunctionBody())
915          return true;
916        break;
917      }
918      continue;
919    }
920
921    if (Code == bitc::DEFINE_ABBREV) {
922      Stream.ReadAbbrevRecord();
923      continue;
924    }
925
926    // Read a record.
927    switch (Stream.ReadRecord(Code, Record)) {
928    default: break;  // Default behavior, ignore unknown content.
929    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
930      if (Record.size() < 1)
931        return Error("Malformed MODULE_CODE_VERSION");
932      // Only version #0 is supported so far.
933      if (Record[0] != 0)
934        return Error("Unknown bitstream version!");
935      break;
936    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
937      std::string S;
938      if (ConvertToString(Record, 0, S))
939        return Error("Invalid MODULE_CODE_TRIPLE record");
940      TheModule->setTargetTriple(S);
941      break;
942    }
943    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
944      std::string S;
945      if (ConvertToString(Record, 0, S))
946        return Error("Invalid MODULE_CODE_DATALAYOUT record");
947      TheModule->setDataLayout(S);
948      break;
949    }
950    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
951      std::string S;
952      if (ConvertToString(Record, 0, S))
953        return Error("Invalid MODULE_CODE_ASM record");
954      TheModule->setModuleInlineAsm(S);
955      break;
956    }
957    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
958      std::string S;
959      if (ConvertToString(Record, 0, S))
960        return Error("Invalid MODULE_CODE_DEPLIB record");
961      TheModule->addLibrary(S);
962      break;
963    }
964    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
965      std::string S;
966      if (ConvertToString(Record, 0, S))
967        return Error("Invalid MODULE_CODE_SECTIONNAME record");
968      SectionTable.push_back(S);
969      break;
970    }
971    // GLOBALVAR: [type, isconst, initid,
972    //             linkage, alignment, section, visibility, threadlocal]
973    case bitc::MODULE_CODE_GLOBALVAR: {
974      if (Record.size() < 6)
975        return Error("Invalid MODULE_CODE_GLOBALVAR record");
976      const Type *Ty = getTypeByID(Record[0]);
977      if (!isa<PointerType>(Ty))
978        return Error("Global not a pointer type!");
979      Ty = cast<PointerType>(Ty)->getElementType();
980
981      bool isConstant = Record[1];
982      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
983      unsigned Alignment = (1 << Record[4]) >> 1;
984      std::string Section;
985      if (Record[5]) {
986        if (Record[5]-1 >= SectionTable.size())
987          return Error("Invalid section ID");
988        Section = SectionTable[Record[5]-1];
989      }
990      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
991      if (Record.size() > 6)
992        Visibility = GetDecodedVisibility(Record[6]);
993      bool isThreadLocal = false;
994      if (Record.size() > 7)
995        isThreadLocal = Record[7];
996
997      GlobalVariable *NewGV =
998        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule);
999      NewGV->setAlignment(Alignment);
1000      if (!Section.empty())
1001        NewGV->setSection(Section);
1002      NewGV->setVisibility(Visibility);
1003      NewGV->setThreadLocal(isThreadLocal);
1004
1005      ValueList.push_back(NewGV);
1006
1007      // Remember which value to use for the global initializer.
1008      if (unsigned InitID = Record[2])
1009        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1010      break;
1011    }
1012    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1013    //             alignment, section, visibility]
1014    case bitc::MODULE_CODE_FUNCTION: {
1015      if (Record.size() < 8)
1016        return Error("Invalid MODULE_CODE_FUNCTION record");
1017      const Type *Ty = getTypeByID(Record[0]);
1018      if (!isa<PointerType>(Ty))
1019        return Error("Function not a pointer type!");
1020      const FunctionType *FTy =
1021        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1022      if (!FTy)
1023        return Error("Function not a pointer to function type!");
1024
1025      Function *Func = new Function(FTy, GlobalValue::ExternalLinkage,
1026                                    "", TheModule);
1027
1028      Func->setCallingConv(Record[1]);
1029      bool isProto = Record[2];
1030      Func->setLinkage(GetDecodedLinkage(Record[3]));
1031
1032      assert(Func->getFunctionType()->getParamAttrs() ==
1033             getParamAttrs(Record[4]));
1034
1035      Func->setAlignment((1 << Record[5]) >> 1);
1036      if (Record[6]) {
1037        if (Record[6]-1 >= SectionTable.size())
1038          return Error("Invalid section ID");
1039        Func->setSection(SectionTable[Record[6]-1]);
1040      }
1041      Func->setVisibility(GetDecodedVisibility(Record[7]));
1042
1043      ValueList.push_back(Func);
1044
1045      // If this is a function with a body, remember the prototype we are
1046      // creating now, so that we can match up the body with them later.
1047      if (!isProto)
1048        FunctionsWithBodies.push_back(Func);
1049      break;
1050    }
1051    // ALIAS: [alias type, aliasee val#, linkage]
1052    case bitc::MODULE_CODE_ALIAS: {
1053      if (Record.size() < 3)
1054        return Error("Invalid MODULE_ALIAS record");
1055      const Type *Ty = getTypeByID(Record[0]);
1056      if (!isa<PointerType>(Ty))
1057        return Error("Function not a pointer type!");
1058
1059      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1060                                           "", 0, TheModule);
1061      ValueList.push_back(NewGA);
1062      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1063      break;
1064    }
1065    /// MODULE_CODE_PURGEVALS: [numvals]
1066    case bitc::MODULE_CODE_PURGEVALS:
1067      // Trim down the value list to the specified size.
1068      if (Record.size() < 1 || Record[0] > ValueList.size())
1069        return Error("Invalid MODULE_PURGEVALS record");
1070      ValueList.shrinkTo(Record[0]);
1071      break;
1072    }
1073    Record.clear();
1074  }
1075
1076  return Error("Premature end of bitstream");
1077}
1078
1079
1080bool BitcodeReader::ParseBitcode() {
1081  TheModule = 0;
1082
1083  if (Buffer->getBufferSize() & 3)
1084    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1085
1086  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1087  Stream.init(BufPtr, BufPtr+Buffer->getBufferSize());
1088
1089  // Sniff for the signature.
1090  if (Stream.Read(8) != 'B' ||
1091      Stream.Read(8) != 'C' ||
1092      Stream.Read(4) != 0x0 ||
1093      Stream.Read(4) != 0xC ||
1094      Stream.Read(4) != 0xE ||
1095      Stream.Read(4) != 0xD)
1096    return Error("Invalid bitcode signature");
1097
1098  // We expect a number of well-defined blocks, though we don't necessarily
1099  // need to understand them all.
1100  while (!Stream.AtEndOfStream()) {
1101    unsigned Code = Stream.ReadCode();
1102
1103    if (Code != bitc::ENTER_SUBBLOCK)
1104      return Error("Invalid record at top-level");
1105
1106    unsigned BlockID = Stream.ReadSubBlockID();
1107
1108    // We only know the MODULE subblock ID.
1109    switch (BlockID) {
1110    case bitc::BLOCKINFO_BLOCK_ID:
1111      if (Stream.ReadBlockInfoBlock())
1112        return Error("Malformed BlockInfoBlock");
1113      break;
1114    case bitc::MODULE_BLOCK_ID:
1115      if (ParseModule(Buffer->getBufferIdentifier()))
1116        return true;
1117      break;
1118    default:
1119      if (Stream.SkipBlock())
1120        return Error("Malformed block record");
1121      break;
1122    }
1123  }
1124
1125  return false;
1126}
1127
1128
1129/// ParseFunctionBody - Lazily parse the specified function body block.
1130bool BitcodeReader::ParseFunctionBody(Function *F) {
1131  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1132    return Error("Malformed block record");
1133
1134  unsigned ModuleValueListSize = ValueList.size();
1135
1136  // Add all the function arguments to the value table.
1137  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1138    ValueList.push_back(I);
1139
1140  unsigned NextValueNo = ValueList.size();
1141  BasicBlock *CurBB = 0;
1142  unsigned CurBBNo = 0;
1143
1144  // Read all the records.
1145  SmallVector<uint64_t, 64> Record;
1146  while (1) {
1147    unsigned Code = Stream.ReadCode();
1148    if (Code == bitc::END_BLOCK) {
1149      if (Stream.ReadBlockEnd())
1150        return Error("Error at end of function block");
1151      break;
1152    }
1153
1154    if (Code == bitc::ENTER_SUBBLOCK) {
1155      switch (Stream.ReadSubBlockID()) {
1156      default:  // Skip unknown content.
1157        if (Stream.SkipBlock())
1158          return Error("Malformed block record");
1159        break;
1160      case bitc::CONSTANTS_BLOCK_ID:
1161        if (ParseConstants()) return true;
1162        NextValueNo = ValueList.size();
1163        break;
1164      case bitc::VALUE_SYMTAB_BLOCK_ID:
1165        if (ParseValueSymbolTable()) return true;
1166        break;
1167      }
1168      continue;
1169    }
1170
1171    if (Code == bitc::DEFINE_ABBREV) {
1172      Stream.ReadAbbrevRecord();
1173      continue;
1174    }
1175
1176    // Read a record.
1177    Record.clear();
1178    Instruction *I = 0;
1179    switch (Stream.ReadRecord(Code, Record)) {
1180    default: // Default behavior: reject
1181      return Error("Unknown instruction");
1182    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1183      if (Record.size() < 1 || Record[0] == 0)
1184        return Error("Invalid DECLAREBLOCKS record");
1185      // Create all the basic blocks for the function.
1186      FunctionBBs.resize(Record[0]);
1187      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1188        FunctionBBs[i] = new BasicBlock("", F);
1189      CurBB = FunctionBBs[0];
1190      continue;
1191
1192    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1193      unsigned OpNum = 0;
1194      Value *LHS, *RHS;
1195      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1196          getValue(Record, OpNum, LHS->getType(), RHS) ||
1197          OpNum+1 != Record.size())
1198        return Error("Invalid BINOP record");
1199
1200      int Opc = GetDecodedBinaryOpcode(Record[OpNum], LHS->getType());
1201      if (Opc == -1) return Error("Invalid BINOP record");
1202      I = BinaryOperator::create((Instruction::BinaryOps)Opc, LHS, RHS);
1203      break;
1204    }
1205    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
1206      unsigned OpNum = 0;
1207      Value *Op;
1208      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1209          OpNum+2 != Record.size())
1210        return Error("Invalid CAST record");
1211
1212      const Type *ResTy = getTypeByID(Record[OpNum]);
1213      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
1214      if (Opc == -1 || ResTy == 0)
1215        return Error("Invalid CAST record");
1216      I = CastInst::create((Instruction::CastOps)Opc, Op, ResTy);
1217      break;
1218    }
1219    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
1220      unsigned OpNum = 0;
1221      Value *BasePtr;
1222      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
1223        return Error("Invalid GEP record");
1224
1225      SmallVector<Value*, 16> GEPIdx;
1226      while (OpNum != Record.size()) {
1227        Value *Op;
1228        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1229          return Error("Invalid GEP record");
1230        GEPIdx.push_back(Op);
1231      }
1232
1233      I = new GetElementPtrInst(BasePtr, &GEPIdx[0], GEPIdx.size());
1234      break;
1235    }
1236
1237    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
1238      unsigned OpNum = 0;
1239      Value *TrueVal, *FalseVal, *Cond;
1240      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
1241          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
1242          getValue(Record, OpNum, Type::Int1Ty, Cond))
1243        return Error("Invalid SELECT record");
1244
1245      I = new SelectInst(Cond, TrueVal, FalseVal);
1246      break;
1247    }
1248
1249    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1250      unsigned OpNum = 0;
1251      Value *Vec, *Idx;
1252      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1253          getValue(Record, OpNum, Type::Int32Ty, Idx))
1254        return Error("Invalid EXTRACTELT record");
1255      I = new ExtractElementInst(Vec, Idx);
1256      break;
1257    }
1258
1259    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1260      unsigned OpNum = 0;
1261      Value *Vec, *Elt, *Idx;
1262      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1263          getValue(Record, OpNum,
1264                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
1265          getValue(Record, OpNum, Type::Int32Ty, Idx))
1266        return Error("Invalid INSERTELT record");
1267      I = new InsertElementInst(Vec, Elt, Idx);
1268      break;
1269    }
1270
1271    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
1272      unsigned OpNum = 0;
1273      Value *Vec1, *Vec2, *Mask;
1274      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
1275          getValue(Record, OpNum, Vec1->getType(), Vec2))
1276        return Error("Invalid SHUFFLEVEC record");
1277
1278      const Type *MaskTy =
1279        VectorType::get(Type::Int32Ty,
1280                        cast<VectorType>(Vec1->getType())->getNumElements());
1281
1282      if (getValue(Record, OpNum, MaskTy, Mask))
1283        return Error("Invalid SHUFFLEVEC record");
1284      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1285      break;
1286    }
1287
1288    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1289      unsigned OpNum = 0;
1290      Value *LHS, *RHS;
1291      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1292          getValue(Record, OpNum, LHS->getType(), RHS) ||
1293          OpNum+1 != Record.size())
1294        return Error("Invalid CMP record");
1295
1296      if (LHS->getType()->isFPOrFPVector())
1297        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1298      else
1299        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1300      break;
1301    }
1302
1303    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1304      if (Record.size() == 0) {
1305        I = new ReturnInst();
1306        break;
1307      } else {
1308        unsigned OpNum = 0;
1309        Value *Op;
1310        if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1311            OpNum != Record.size())
1312          return Error("Invalid RET record");
1313        I = new ReturnInst(Op);
1314        break;
1315      }
1316    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1317      if (Record.size() != 1 && Record.size() != 3)
1318        return Error("Invalid BR record");
1319      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1320      if (TrueDest == 0)
1321        return Error("Invalid BR record");
1322
1323      if (Record.size() == 1)
1324        I = new BranchInst(TrueDest);
1325      else {
1326        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1327        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1328        if (FalseDest == 0 || Cond == 0)
1329          return Error("Invalid BR record");
1330        I = new BranchInst(TrueDest, FalseDest, Cond);
1331      }
1332      break;
1333    }
1334    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1335      if (Record.size() < 3 || (Record.size() & 1) == 0)
1336        return Error("Invalid SWITCH record");
1337      const Type *OpTy = getTypeByID(Record[0]);
1338      Value *Cond = getFnValueByID(Record[1], OpTy);
1339      BasicBlock *Default = getBasicBlock(Record[2]);
1340      if (OpTy == 0 || Cond == 0 || Default == 0)
1341        return Error("Invalid SWITCH record");
1342      unsigned NumCases = (Record.size()-3)/2;
1343      SwitchInst *SI = new SwitchInst(Cond, Default, NumCases);
1344      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1345        ConstantInt *CaseVal =
1346          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1347        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1348        if (CaseVal == 0 || DestBB == 0) {
1349          delete SI;
1350          return Error("Invalid SWITCH record!");
1351        }
1352        SI->addCase(CaseVal, DestBB);
1353      }
1354      I = SI;
1355      break;
1356    }
1357
1358    case bitc::FUNC_CODE_INST_INVOKE: { // INVOKE: [cc,fnty, op0,op1,op2, ...]
1359      if (Record.size() < 4) return Error("Invalid INVOKE record");
1360      unsigned CCInfo = Record[1];
1361      BasicBlock *NormalBB = getBasicBlock(Record[2]);
1362      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
1363
1364      unsigned OpNum = 4;
1365      Value *Callee;
1366      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1367        return Error("Invalid INVOKE record");
1368
1369      const PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
1370      const FunctionType *FTy = !CalleeTy ? 0 :
1371        dyn_cast<FunctionType>(CalleeTy->getElementType());
1372
1373      // Check that the right number of fixed parameters are here.
1374      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
1375          Record.size() < OpNum+FTy->getNumParams())
1376        return Error("Invalid INVOKE record");
1377
1378      assert(FTy->getParamAttrs() == getParamAttrs(Record[0]));
1379
1380      SmallVector<Value*, 16> Ops;
1381      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1382        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1383        if (Ops.back() == 0) return Error("Invalid INVOKE record");
1384      }
1385
1386      if (!FTy->isVarArg()) {
1387        if (Record.size() != OpNum)
1388          return Error("Invalid INVOKE record");
1389      } else {
1390        // Read type/value pairs for varargs params.
1391        while (OpNum != Record.size()) {
1392          Value *Op;
1393          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1394            return Error("Invalid INVOKE record");
1395          Ops.push_back(Op);
1396        }
1397      }
1398
1399      I = new InvokeInst(Callee, NormalBB, UnwindBB, &Ops[0], Ops.size());
1400      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1401      break;
1402    }
1403    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1404      I = new UnwindInst();
1405      break;
1406    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1407      I = new UnreachableInst();
1408      break;
1409    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
1410      if (Record.size() < 1 || ((Record.size()-1)&1))
1411        return Error("Invalid PHI record");
1412      const Type *Ty = getTypeByID(Record[0]);
1413      if (!Ty) return Error("Invalid PHI record");
1414
1415      PHINode *PN = new PHINode(Ty);
1416      PN->reserveOperandSpace(Record.size()-1);
1417
1418      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
1419        Value *V = getFnValueByID(Record[1+i], Ty);
1420        BasicBlock *BB = getBasicBlock(Record[2+i]);
1421        if (!V || !BB) return Error("Invalid PHI record");
1422        PN->addIncoming(V, BB);
1423      }
1424      I = PN;
1425      break;
1426    }
1427
1428    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1429      if (Record.size() < 3)
1430        return Error("Invalid MALLOC record");
1431      const PointerType *Ty =
1432        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1433      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1434      unsigned Align = Record[2];
1435      if (!Ty || !Size) return Error("Invalid MALLOC record");
1436      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1437      break;
1438    }
1439    case bitc::FUNC_CODE_INST_FREE: { // FREE: [op, opty]
1440      unsigned OpNum = 0;
1441      Value *Op;
1442      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1443          OpNum != Record.size())
1444        return Error("Invalid FREE record");
1445      I = new FreeInst(Op);
1446      break;
1447    }
1448    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1449      if (Record.size() < 3)
1450        return Error("Invalid ALLOCA record");
1451      const PointerType *Ty =
1452        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1453      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1454      unsigned Align = Record[2];
1455      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1456      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1457      break;
1458    }
1459    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1460      unsigned OpNum = 0;
1461      Value *Op;
1462      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1463          OpNum+2 != Record.size())
1464        return Error("Invalid LOAD record");
1465
1466      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1467      break;
1468    }
1469    case bitc::FUNC_CODE_INST_STORE: { // STORE:[val, valty, ptr, align, vol]
1470      unsigned OpNum = 0;
1471      Value *Val, *Ptr;
1472      if (getValueTypePair(Record, OpNum, NextValueNo, Val) ||
1473          getValue(Record, OpNum, PointerType::get(Val->getType()), Ptr) ||
1474          OpNum+2 != Record.size())
1475        return Error("Invalid STORE record");
1476
1477      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1478      break;
1479    }
1480    case bitc::FUNC_CODE_INST_CALL: { // CALL: [cc, fnty, fnid, arg0, arg1...]
1481      if (Record.size() < 2)
1482        return Error("Invalid CALL record");
1483
1484      unsigned CCInfo = Record[1];
1485
1486      unsigned OpNum = 2;
1487      Value *Callee;
1488      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1489        return Error("Invalid CALL record");
1490
1491      const PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
1492      const FunctionType *FTy = 0;
1493      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1494      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
1495        return Error("Invalid CALL record");
1496
1497      assert(FTy->getParamAttrs() == getParamAttrs(Record[0]));
1498
1499      SmallVector<Value*, 16> Args;
1500      // Read the fixed params.
1501      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1502        Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1503        if (Args.back() == 0) return Error("Invalid CALL record");
1504      }
1505
1506      // Read type/value pairs for varargs params.
1507      if (!FTy->isVarArg()) {
1508        if (OpNum != Record.size())
1509          return Error("Invalid CALL record");
1510      } else {
1511        while (OpNum != Record.size()) {
1512          Value *Op;
1513          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1514            return Error("Invalid CALL record");
1515          Args.push_back(Op);
1516        }
1517      }
1518
1519      I = new CallInst(Callee, Args.begin(), Args.end());
1520      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1521      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1522      break;
1523    }
1524    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1525      if (Record.size() < 3)
1526        return Error("Invalid VAARG record");
1527      const Type *OpTy = getTypeByID(Record[0]);
1528      Value *Op = getFnValueByID(Record[1], OpTy);
1529      const Type *ResTy = getTypeByID(Record[2]);
1530      if (!OpTy || !Op || !ResTy)
1531        return Error("Invalid VAARG record");
1532      I = new VAArgInst(Op, ResTy);
1533      break;
1534    }
1535    }
1536
1537    // Add instruction to end of current BB.  If there is no current BB, reject
1538    // this file.
1539    if (CurBB == 0) {
1540      delete I;
1541      return Error("Invalid instruction with no BB");
1542    }
1543    CurBB->getInstList().push_back(I);
1544
1545    // If this was a terminator instruction, move to the next block.
1546    if (isa<TerminatorInst>(I)) {
1547      ++CurBBNo;
1548      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1549    }
1550
1551    // Non-void values get registered in the value table for future use.
1552    if (I && I->getType() != Type::VoidTy)
1553      ValueList.AssignValue(I, NextValueNo++);
1554  }
1555
1556  // Check the function list for unresolved values.
1557  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1558    if (A->getParent() == 0) {
1559      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1560      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1561        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1562          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1563          delete A;
1564        }
1565      }
1566      return Error("Never resolved value found in function!");
1567    }
1568  }
1569
1570  // Trim the value list down to the size it was before we parsed this function.
1571  ValueList.shrinkTo(ModuleValueListSize);
1572  std::vector<BasicBlock*>().swap(FunctionBBs);
1573
1574  return false;
1575}
1576
1577//===----------------------------------------------------------------------===//
1578// ModuleProvider implementation
1579//===----------------------------------------------------------------------===//
1580
1581
1582bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1583  // If it already is material, ignore the request.
1584  if (!F->hasNotBeenReadFromBitcode()) return false;
1585
1586  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1587    DeferredFunctionInfo.find(F);
1588  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1589
1590  // Move the bit stream to the saved position of the deferred function body and
1591  // restore the real linkage type for the function.
1592  Stream.JumpToBit(DFII->second.first);
1593  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1594
1595  if (ParseFunctionBody(F)) {
1596    if (ErrInfo) *ErrInfo = ErrorString;
1597    return true;
1598  }
1599
1600  // Upgrade any old intrinsic calls in the function.
1601  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
1602       E = UpgradedIntrinsics.end(); I != E; ++I) {
1603    if (I->first != I->second) {
1604      for (Value::use_iterator UI = I->first->use_begin(),
1605           UE = I->first->use_end(); UI != UE; ) {
1606        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1607          UpgradeIntrinsicCall(CI, I->second);
1608      }
1609    }
1610  }
1611
1612  return false;
1613}
1614
1615void BitcodeReader::dematerializeFunction(Function *F) {
1616  // If this function isn't materialized, or if it is a proto, this is a noop.
1617  if (F->hasNotBeenReadFromBitcode() || F->isDeclaration())
1618    return;
1619
1620  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
1621
1622  // Just forget the function body, we can remat it later.
1623  F->deleteBody();
1624  F->setLinkage(GlobalValue::GhostLinkage);
1625}
1626
1627
1628Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
1629  for (DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1630       DeferredFunctionInfo.begin(), E = DeferredFunctionInfo.end(); I != E;
1631       ++I) {
1632    Function *F = I->first;
1633    if (F->hasNotBeenReadFromBitcode() &&
1634        materializeFunction(F, ErrInfo))
1635      return 0;
1636  }
1637
1638  // Upgrade any intrinsic calls that slipped through (should not happen!) and
1639  // delete the old functions to clean up. We can't do this unless the entire
1640  // module is materialized because there could always be another function body
1641  // with calls to the old function.
1642  for (std::vector<std::pair<Function*, Function*> >::iterator I =
1643       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
1644    if (I->first != I->second) {
1645      for (Value::use_iterator UI = I->first->use_begin(),
1646           UE = I->first->use_end(); UI != UE; ) {
1647        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1648          UpgradeIntrinsicCall(CI, I->second);
1649      }
1650      ValueList.replaceUsesOfWith(I->first, I->second);
1651      I->first->eraseFromParent();
1652    }
1653  }
1654  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
1655
1656  return TheModule;
1657}
1658
1659
1660/// This method is provided by the parent ModuleProvde class and overriden
1661/// here. It simply releases the module from its provided and frees up our
1662/// state.
1663/// @brief Release our hold on the generated module
1664Module *BitcodeReader::releaseModule(std::string *ErrInfo) {
1665  // Since we're losing control of this Module, we must hand it back complete
1666  Module *M = ModuleProvider::releaseModule(ErrInfo);
1667  FreeState();
1668  return M;
1669}
1670
1671
1672//===----------------------------------------------------------------------===//
1673// External interface
1674//===----------------------------------------------------------------------===//
1675
1676/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1677///
1678ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1679                                               std::string *ErrMsg) {
1680  BitcodeReader *R = new BitcodeReader(Buffer);
1681  if (R->ParseBitcode()) {
1682    if (ErrMsg)
1683      *ErrMsg = R->getErrorString();
1684
1685    // Don't let the BitcodeReader dtor delete 'Buffer'.
1686    R->releaseMemoryBuffer();
1687    delete R;
1688    return 0;
1689  }
1690  return R;
1691}
1692
1693/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
1694/// If an error occurs, return null and fill in *ErrMsg if non-null.
1695Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
1696  BitcodeReader *R;
1697  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
1698  if (!R) return 0;
1699
1700  // Read in the entire module.
1701  Module *M = R->materializeModule(ErrMsg);
1702
1703  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
1704  // there was an error.
1705  R->releaseMemoryBuffer();
1706
1707  // If there was no error, tell ModuleProvider not to delete it when its dtor
1708  // is run.
1709  if (M)
1710    M = R->releaseModule(ErrMsg);
1711
1712  delete R;
1713  return M;
1714}
1715