BitcodeReader.cpp revision f4a97da4072a2ee4aca3c668a9fa113c06fdef8d 
1//===- BitcodeReader.cpp - Internal BitcodeReader implementation ----------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// 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/AutoUpgrade.h"
22#include "llvm/ADT/SmallString.h"
23#include "llvm/ADT/SmallVector.h"
24#include "llvm/Support/MathExtras.h"
25#include "llvm/Support/MemoryBuffer.h"
26#include "llvm/OperandTraits.h"
27using namespace llvm;
28
29void BitcodeReader::FreeState() {
30  delete Buffer;
31  Buffer = 0;
32  std::vector<PATypeHolder>().swap(TypeList);
33  ValueList.clear();
34
35  std::vector<PAListPtr>().swap(ParamAttrs);
36  std::vector<BasicBlock*>().swap(FunctionBBs);
37  std::vector<Function*>().swap(FunctionsWithBodies);
38  DeferredFunctionInfo.clear();
39}
40
41//===----------------------------------------------------------------------===//
42//  Helper functions to implement forward reference resolution, etc.
43//===----------------------------------------------------------------------===//
44
45/// ConvertToString - Convert a string from a record into an std::string, return
46/// true on failure.
47template<typename StrTy>
48static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
49                            StrTy &Result) {
50  if (Idx > Record.size())
51    return true;
52
53  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
54    Result += (char)Record[i];
55  return false;
56}
57
58static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
59  switch (Val) {
60  default: // Map unknown/new linkages to external
61  case 0: return GlobalValue::ExternalLinkage;
62  case 1: return GlobalValue::WeakLinkage;
63  case 2: return GlobalValue::AppendingLinkage;
64  case 3: return GlobalValue::InternalLinkage;
65  case 4: return GlobalValue::LinkOnceLinkage;
66  case 5: return GlobalValue::DLLImportLinkage;
67  case 6: return GlobalValue::DLLExportLinkage;
68  case 7: return GlobalValue::ExternalWeakLinkage;
69  case 8: return GlobalValue::CommonLinkage;
70  }
71}
72
73static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
74  switch (Val) {
75  default: // Map unknown visibilities to default.
76  case 0: return GlobalValue::DefaultVisibility;
77  case 1: return GlobalValue::HiddenVisibility;
78  case 2: return GlobalValue::ProtectedVisibility;
79  }
80}
81
82static int GetDecodedCastOpcode(unsigned Val) {
83  switch (Val) {
84  default: return -1;
85  case bitc::CAST_TRUNC   : return Instruction::Trunc;
86  case bitc::CAST_ZEXT    : return Instruction::ZExt;
87  case bitc::CAST_SEXT    : return Instruction::SExt;
88  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
89  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
90  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
91  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
92  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
93  case bitc::CAST_FPEXT   : return Instruction::FPExt;
94  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
95  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
96  case bitc::CAST_BITCAST : return Instruction::BitCast;
97  }
98}
99static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
100  switch (Val) {
101  default: return -1;
102  case bitc::BINOP_ADD:  return Instruction::Add;
103  case bitc::BINOP_SUB:  return Instruction::Sub;
104  case bitc::BINOP_MUL:  return Instruction::Mul;
105  case bitc::BINOP_UDIV: return Instruction::UDiv;
106  case bitc::BINOP_SDIV:
107    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
108  case bitc::BINOP_UREM: return Instruction::URem;
109  case bitc::BINOP_SREM:
110    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
111  case bitc::BINOP_SHL:  return Instruction::Shl;
112  case bitc::BINOP_LSHR: return Instruction::LShr;
113  case bitc::BINOP_ASHR: return Instruction::AShr;
114  case bitc::BINOP_AND:  return Instruction::And;
115  case bitc::BINOP_OR:   return Instruction::Or;
116  case bitc::BINOP_XOR:  return Instruction::Xor;
117  }
118}
119
120namespace llvm {
121namespace {
122  /// @brief A class for maintaining the slot number definition
123  /// as a placeholder for the actual definition for forward constants defs.
124  class ConstantPlaceHolder : public ConstantExpr {
125    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
126    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
127  public:
128    // allocate space for exactly one operand
129    void *operator new(size_t s) {
130      return User::operator new(s, 1);
131    }
132    explicit ConstantPlaceHolder(const Type *Ty)
133      : ConstantExpr(Ty, Instruction::UserOp1, &Op<0>(), 1) {
134      Op<0>() = UndefValue::get(Type::Int32Ty);
135    }
136
137    /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
138    static inline bool classof(const ConstantPlaceHolder *) { return true; }
139    static bool classof(const Value *V) {
140      return isa<ConstantExpr>(V) &&
141             cast<ConstantExpr>(V)->getOpcode() == Instruction::UserOp1;
142    }
143
144
145    /// Provide fast operand accessors
146    DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
147  };
148}
149
150
151  // FIXME: can we inherit this from ConstantExpr?
152template <>
153struct OperandTraits<ConstantPlaceHolder> : FixedNumOperandTraits<1> {
154};
155
156DEFINE_TRANSPARENT_OPERAND_ACCESSORS(ConstantPlaceHolder, Value)
157}
158
159void BitcodeReaderValueList::resize(unsigned Desired) {
160  if (Desired > Capacity) {
161    // Since we expect many values to come from the bitcode file we better
162    // allocate the double amount, so that the array size grows exponentially
163    // at each reallocation.  Also, add a small amount of 100 extra elements
164    // each time, to reallocate less frequently when the array is still small.
165    //
166    Capacity = Desired * 2 + 100;
167    Use *New = allocHungoffUses(Capacity);
168    Use *Old = OperandList;
169    unsigned Ops = getNumOperands();
170    for (int i(Ops - 1); i >= 0; --i)
171      New[i] = Old[i].get();
172    OperandList = New;
173    if (Old) Use::zap(Old, Old + Ops, true);
174  }
175}
176
177Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
178                                                    const Type *Ty) {
179  if (Idx >= size()) {
180    // Insert a bunch of null values.
181    resize(Idx + 1);
182    NumOperands = Idx+1;
183  }
184
185  if (Value *V = OperandList[Idx]) {
186    assert(Ty == V->getType() && "Type mismatch in constant table!");
187    return cast<Constant>(V);
188  }
189
190  // Create and return a placeholder, which will later be RAUW'd.
191  Constant *C = new ConstantPlaceHolder(Ty);
192  OperandList[Idx] = C;
193  return C;
194}
195
196Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
197  if (Idx >= size()) {
198    // Insert a bunch of null values.
199    resize(Idx + 1);
200    NumOperands = Idx+1;
201  }
202
203  if (Value *V = OperandList[Idx]) {
204    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
205    return V;
206  }
207
208  // No type specified, must be invalid reference.
209  if (Ty == 0) return 0;
210
211  // Create and return a placeholder, which will later be RAUW'd.
212  Value *V = new Argument(Ty);
213  OperandList[Idx] = V;
214  return V;
215}
216
217/// ResolveConstantForwardRefs - Once all constants are read, this method bulk
218/// resolves any forward references.  The idea behind this is that we sometimes
219/// get constants (such as large arrays) which reference *many* forward ref
220/// constants.  Replacing each of these causes a lot of thrashing when
221/// building/reuniquing the constant.  Instead of doing this, we look at all the
222/// uses and rewrite all the place holders at once for any constant that uses
223/// a placeholder.
224void BitcodeReaderValueList::ResolveConstantForwardRefs() {
225  // Sort the values by-pointer so that they are efficient to look up with a
226  // binary search.
227  std::sort(ResolveConstants.begin(), ResolveConstants.end());
228
229  SmallVector<Constant*, 64> NewOps;
230
231  while (!ResolveConstants.empty()) {
232    Value *RealVal = getOperand(ResolveConstants.back().second);
233    Constant *Placeholder = ResolveConstants.back().first;
234    ResolveConstants.pop_back();
235
236    // Loop over all users of the placeholder, updating them to reference the
237    // new value.  If they reference more than one placeholder, update them all
238    // at once.
239    while (!Placeholder->use_empty()) {
240      User *U = Placeholder->use_back();
241      // If the using object isn't uniqued, just update the operands.  This
242      // handles instructions and initializers for global variables.
243      if (!isa<Constant>(U) || isa<GlobalValue>(U)) {
244        U->replaceUsesOfWith(Placeholder, RealVal);
245        continue;
246      }
247
248      // Otherwise, we have a constant that uses the placeholder.  Replace that
249      // constant with a new constant that has *all* placeholder uses updated.
250      Constant *UserC = cast<Constant>(U);
251      for (User::op_iterator I = UserC->op_begin(), E = UserC->op_end();
252           I != E; ++I) {
253        Value *NewOp;
254        if (!isa<ConstantPlaceHolder>(*I)) {
255          // Not a placeholder reference.
256          NewOp = *I;
257        } else if (*I == Placeholder) {
258          // Common case is that it just references this one placeholder.
259          NewOp = RealVal;
260        } else {
261          // Otherwise, look up the placeholder in ResolveConstants.
262          ResolveConstantsTy::iterator It =
263            std::lower_bound(ResolveConstants.begin(), ResolveConstants.end(),
264                             std::pair<Constant*, unsigned>(cast<Constant>(*I),
265                                                            0));
266          assert(It != ResolveConstants.end() && It->first == *I);
267          NewOp = this->getOperand(It->second);
268        }
269
270        NewOps.push_back(cast<Constant>(NewOp));
271      }
272
273      // Make the new constant.
274      Constant *NewC;
275      if (ConstantArray *UserCA = dyn_cast<ConstantArray>(UserC)) {
276        NewC = ConstantArray::get(UserCA->getType(), &NewOps[0], NewOps.size());
277      } else if (isa<ConstantStruct>(UserC)) {
278        NewC = ConstantStruct::get(&NewOps[0], NewOps.size());
279      } else if (isa<ConstantVector>(UserC)) {
280        NewC = ConstantVector::get(&NewOps[0], NewOps.size());
281      } else {
282        // Must be a constant expression.
283        NewC = cast<ConstantExpr>(UserC)->getWithOperands(&NewOps[0],
284                                                          NewOps.size());
285      }
286
287      UserC->replaceAllUsesWith(NewC);
288      UserC->destroyConstant();
289      NewOps.clear();
290    }
291
292    delete Placeholder;
293  }
294}
295
296
297const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
298  // If the TypeID is in range, return it.
299  if (ID < TypeList.size())
300    return TypeList[ID].get();
301  if (!isTypeTable) return 0;
302
303  // The type table allows forward references.  Push as many Opaque types as
304  // needed to get up to ID.
305  while (TypeList.size() <= ID)
306    TypeList.push_back(OpaqueType::get());
307  return TypeList.back().get();
308}
309
310//===----------------------------------------------------------------------===//
311//  Functions for parsing blocks from the bitcode file
312//===----------------------------------------------------------------------===//
313
314bool BitcodeReader::ParseParamAttrBlock() {
315  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
316    return Error("Malformed block record");
317
318  if (!ParamAttrs.empty())
319    return Error("Multiple PARAMATTR blocks found!");
320
321  SmallVector<uint64_t, 64> Record;
322
323  SmallVector<ParamAttrsWithIndex, 8> Attrs;
324
325  // Read all the records.
326  while (1) {
327    unsigned Code = Stream.ReadCode();
328    if (Code == bitc::END_BLOCK) {
329      if (Stream.ReadBlockEnd())
330        return Error("Error at end of PARAMATTR block");
331      return false;
332    }
333
334    if (Code == bitc::ENTER_SUBBLOCK) {
335      // No known subblocks, always skip them.
336      Stream.ReadSubBlockID();
337      if (Stream.SkipBlock())
338        return Error("Malformed block record");
339      continue;
340    }
341
342    if (Code == bitc::DEFINE_ABBREV) {
343      Stream.ReadAbbrevRecord();
344      continue;
345    }
346
347    // Read a record.
348    Record.clear();
349    switch (Stream.ReadRecord(Code, Record)) {
350    default:  // Default behavior: ignore.
351      break;
352    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
353      if (Record.size() & 1)
354        return Error("Invalid ENTRY record");
355
356      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
357        if (Record[i+1] != ParamAttr::None)
358          Attrs.push_back(ParamAttrsWithIndex::get(Record[i], Record[i+1]));
359      }
360
361      ParamAttrs.push_back(PAListPtr::get(Attrs.begin(), Attrs.end()));
362      Attrs.clear();
363      break;
364    }
365    }
366  }
367}
368
369
370bool BitcodeReader::ParseTypeTable() {
371  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID))
372    return Error("Malformed block record");
373
374  if (!TypeList.empty())
375    return Error("Multiple TYPE_BLOCKs found!");
376
377  SmallVector<uint64_t, 64> Record;
378  unsigned NumRecords = 0;
379
380  // Read all the records for this type table.
381  while (1) {
382    unsigned Code = Stream.ReadCode();
383    if (Code == bitc::END_BLOCK) {
384      if (NumRecords != TypeList.size())
385        return Error("Invalid type forward reference in TYPE_BLOCK");
386      if (Stream.ReadBlockEnd())
387        return Error("Error at end of type table block");
388      return false;
389    }
390
391    if (Code == bitc::ENTER_SUBBLOCK) {
392      // No known subblocks, always skip them.
393      Stream.ReadSubBlockID();
394      if (Stream.SkipBlock())
395        return Error("Malformed block record");
396      continue;
397    }
398
399    if (Code == bitc::DEFINE_ABBREV) {
400      Stream.ReadAbbrevRecord();
401      continue;
402    }
403
404    // Read a record.
405    Record.clear();
406    const Type *ResultTy = 0;
407    switch (Stream.ReadRecord(Code, Record)) {
408    default:  // Default behavior: unknown type.
409      ResultTy = 0;
410      break;
411    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
412      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
413      // type list.  This allows us to reserve space.
414      if (Record.size() < 1)
415        return Error("Invalid TYPE_CODE_NUMENTRY record");
416      TypeList.reserve(Record[0]);
417      continue;
418    case bitc::TYPE_CODE_VOID:      // VOID
419      ResultTy = Type::VoidTy;
420      break;
421    case bitc::TYPE_CODE_FLOAT:     // FLOAT
422      ResultTy = Type::FloatTy;
423      break;
424    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
425      ResultTy = Type::DoubleTy;
426      break;
427    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
428      ResultTy = Type::X86_FP80Ty;
429      break;
430    case bitc::TYPE_CODE_FP128:     // FP128
431      ResultTy = Type::FP128Ty;
432      break;
433    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
434      ResultTy = Type::PPC_FP128Ty;
435      break;
436    case bitc::TYPE_CODE_LABEL:     // LABEL
437      ResultTy = Type::LabelTy;
438      break;
439    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
440      ResultTy = 0;
441      break;
442    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
443      if (Record.size() < 1)
444        return Error("Invalid Integer type record");
445
446      ResultTy = IntegerType::get(Record[0]);
447      break;
448    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
449                                    //          [pointee type, address space]
450      if (Record.size() < 1)
451        return Error("Invalid POINTER type record");
452      unsigned AddressSpace = 0;
453      if (Record.size() == 2)
454        AddressSpace = Record[1];
455      ResultTy = PointerType::get(getTypeByID(Record[0], true), AddressSpace);
456      break;
457    }
458    case bitc::TYPE_CODE_FUNCTION: {
459      // FIXME: attrid is dead, remove it in LLVM 3.0
460      // FUNCTION: [vararg, attrid, retty, paramty x N]
461      if (Record.size() < 3)
462        return Error("Invalid FUNCTION type record");
463      std::vector<const Type*> ArgTys;
464      for (unsigned i = 3, e = Record.size(); i != e; ++i)
465        ArgTys.push_back(getTypeByID(Record[i], true));
466
467      ResultTy = FunctionType::get(getTypeByID(Record[2], true), ArgTys,
468                                   Record[0]);
469      break;
470    }
471    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, eltty x N]
472      if (Record.size() < 1)
473        return Error("Invalid STRUCT type record");
474      std::vector<const Type*> EltTys;
475      for (unsigned i = 1, e = Record.size(); i != e; ++i)
476        EltTys.push_back(getTypeByID(Record[i], true));
477      ResultTy = StructType::get(EltTys, Record[0]);
478      break;
479    }
480    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
481      if (Record.size() < 2)
482        return Error("Invalid ARRAY type record");
483      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
484      break;
485    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
486      if (Record.size() < 2)
487        return Error("Invalid VECTOR type record");
488      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
489      break;
490    }
491
492    if (NumRecords == TypeList.size()) {
493      // If this is a new type slot, just append it.
494      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
495      ++NumRecords;
496    } else if (ResultTy == 0) {
497      // Otherwise, this was forward referenced, so an opaque type was created,
498      // but the result type is actually just an opaque.  Leave the one we
499      // created previously.
500      ++NumRecords;
501    } else {
502      // Otherwise, this was forward referenced, so an opaque type was created.
503      // Resolve the opaque type to the real type now.
504      assert(NumRecords < TypeList.size() && "Typelist imbalance");
505      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
506
507      // Don't directly push the new type on the Tab. Instead we want to replace
508      // the opaque type we previously inserted with the new concrete value. The
509      // refinement from the abstract (opaque) type to the new type causes all
510      // uses of the abstract type to use the concrete type (NewTy). This will
511      // also cause the opaque type to be deleted.
512      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
513
514      // This should have replaced the old opaque type with the new type in the
515      // value table... or with a preexisting type that was already in the
516      // system.  Let's just make sure it did.
517      assert(TypeList[NumRecords-1].get() != OldTy &&
518             "refineAbstractType didn't work!");
519    }
520  }
521}
522
523
524bool BitcodeReader::ParseTypeSymbolTable() {
525  if (Stream.EnterSubBlock(bitc::TYPE_SYMTAB_BLOCK_ID))
526    return Error("Malformed block record");
527
528  SmallVector<uint64_t, 64> Record;
529
530  // Read all the records for this type table.
531  std::string TypeName;
532  while (1) {
533    unsigned Code = Stream.ReadCode();
534    if (Code == bitc::END_BLOCK) {
535      if (Stream.ReadBlockEnd())
536        return Error("Error at end of type symbol table block");
537      return false;
538    }
539
540    if (Code == bitc::ENTER_SUBBLOCK) {
541      // No known subblocks, always skip them.
542      Stream.ReadSubBlockID();
543      if (Stream.SkipBlock())
544        return Error("Malformed block record");
545      continue;
546    }
547
548    if (Code == bitc::DEFINE_ABBREV) {
549      Stream.ReadAbbrevRecord();
550      continue;
551    }
552
553    // Read a record.
554    Record.clear();
555    switch (Stream.ReadRecord(Code, Record)) {
556    default:  // Default behavior: unknown type.
557      break;
558    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namechar x N]
559      if (ConvertToString(Record, 1, TypeName))
560        return Error("Invalid TST_ENTRY record");
561      unsigned TypeID = Record[0];
562      if (TypeID >= TypeList.size())
563        return Error("Invalid Type ID in TST_ENTRY record");
564
565      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
566      TypeName.clear();
567      break;
568    }
569  }
570}
571
572bool BitcodeReader::ParseValueSymbolTable() {
573  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
574    return Error("Malformed block record");
575
576  SmallVector<uint64_t, 64> Record;
577
578  // Read all the records for this value table.
579  SmallString<128> ValueName;
580  while (1) {
581    unsigned Code = Stream.ReadCode();
582    if (Code == bitc::END_BLOCK) {
583      if (Stream.ReadBlockEnd())
584        return Error("Error at end of value symbol table block");
585      return false;
586    }
587    if (Code == bitc::ENTER_SUBBLOCK) {
588      // No known subblocks, always skip them.
589      Stream.ReadSubBlockID();
590      if (Stream.SkipBlock())
591        return Error("Malformed block record");
592      continue;
593    }
594
595    if (Code == bitc::DEFINE_ABBREV) {
596      Stream.ReadAbbrevRecord();
597      continue;
598    }
599
600    // Read a record.
601    Record.clear();
602    switch (Stream.ReadRecord(Code, Record)) {
603    default:  // Default behavior: unknown type.
604      break;
605    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
606      if (ConvertToString(Record, 1, ValueName))
607        return Error("Invalid TST_ENTRY record");
608      unsigned ValueID = Record[0];
609      if (ValueID >= ValueList.size())
610        return Error("Invalid Value ID in VST_ENTRY record");
611      Value *V = ValueList[ValueID];
612
613      V->setName(&ValueName[0], ValueName.size());
614      ValueName.clear();
615      break;
616    }
617    case bitc::VST_CODE_BBENTRY: {
618      if (ConvertToString(Record, 1, ValueName))
619        return Error("Invalid VST_BBENTRY record");
620      BasicBlock *BB = getBasicBlock(Record[0]);
621      if (BB == 0)
622        return Error("Invalid BB ID in VST_BBENTRY record");
623
624      BB->setName(&ValueName[0], ValueName.size());
625      ValueName.clear();
626      break;
627    }
628    }
629  }
630}
631
632/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
633/// the LSB for dense VBR encoding.
634static uint64_t DecodeSignRotatedValue(uint64_t V) {
635  if ((V & 1) == 0)
636    return V >> 1;
637  if (V != 1)
638    return -(V >> 1);
639  // There is no such thing as -0 with integers.  "-0" really means MININT.
640  return 1ULL << 63;
641}
642
643/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
644/// values and aliases that we can.
645bool BitcodeReader::ResolveGlobalAndAliasInits() {
646  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
647  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
648
649  GlobalInitWorklist.swap(GlobalInits);
650  AliasInitWorklist.swap(AliasInits);
651
652  while (!GlobalInitWorklist.empty()) {
653    unsigned ValID = GlobalInitWorklist.back().second;
654    if (ValID >= ValueList.size()) {
655      // Not ready to resolve this yet, it requires something later in the file.
656      GlobalInits.push_back(GlobalInitWorklist.back());
657    } else {
658      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
659        GlobalInitWorklist.back().first->setInitializer(C);
660      else
661        return Error("Global variable initializer is not a constant!");
662    }
663    GlobalInitWorklist.pop_back();
664  }
665
666  while (!AliasInitWorklist.empty()) {
667    unsigned ValID = AliasInitWorklist.back().second;
668    if (ValID >= ValueList.size()) {
669      AliasInits.push_back(AliasInitWorklist.back());
670    } else {
671      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
672        AliasInitWorklist.back().first->setAliasee(C);
673      else
674        return Error("Alias initializer is not a constant!");
675    }
676    AliasInitWorklist.pop_back();
677  }
678  return false;
679}
680
681
682bool BitcodeReader::ParseConstants() {
683  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
684    return Error("Malformed block record");
685
686  SmallVector<uint64_t, 64> Record;
687
688  // Read all the records for this value table.
689  const Type *CurTy = Type::Int32Ty;
690  unsigned NextCstNo = ValueList.size();
691  while (1) {
692    unsigned Code = Stream.ReadCode();
693    if (Code == bitc::END_BLOCK)
694      break;
695
696    if (Code == bitc::ENTER_SUBBLOCK) {
697      // No known subblocks, always skip them.
698      Stream.ReadSubBlockID();
699      if (Stream.SkipBlock())
700        return Error("Malformed block record");
701      continue;
702    }
703
704    if (Code == bitc::DEFINE_ABBREV) {
705      Stream.ReadAbbrevRecord();
706      continue;
707    }
708
709    // Read a record.
710    Record.clear();
711    Value *V = 0;
712    switch (Stream.ReadRecord(Code, Record)) {
713    default:  // Default behavior: unknown constant
714    case bitc::CST_CODE_UNDEF:     // UNDEF
715      V = UndefValue::get(CurTy);
716      break;
717    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
718      if (Record.empty())
719        return Error("Malformed CST_SETTYPE record");
720      if (Record[0] >= TypeList.size())
721        return Error("Invalid Type ID in CST_SETTYPE record");
722      CurTy = TypeList[Record[0]];
723      continue;  // Skip the ValueList manipulation.
724    case bitc::CST_CODE_NULL:      // NULL
725      V = Constant::getNullValue(CurTy);
726      break;
727    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
728      if (!isa<IntegerType>(CurTy) || Record.empty())
729        return Error("Invalid CST_INTEGER record");
730      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
731      break;
732    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
733      if (!isa<IntegerType>(CurTy) || Record.empty())
734        return Error("Invalid WIDE_INTEGER record");
735
736      unsigned NumWords = Record.size();
737      SmallVector<uint64_t, 8> Words;
738      Words.resize(NumWords);
739      for (unsigned i = 0; i != NumWords; ++i)
740        Words[i] = DecodeSignRotatedValue(Record[i]);
741      V = ConstantInt::get(APInt(cast<IntegerType>(CurTy)->getBitWidth(),
742                                 NumWords, &Words[0]));
743      break;
744    }
745    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
746      if (Record.empty())
747        return Error("Invalid FLOAT record");
748      if (CurTy == Type::FloatTy)
749        V = ConstantFP::get(APFloat(APInt(32, (uint32_t)Record[0])));
750      else if (CurTy == Type::DoubleTy)
751        V = ConstantFP::get(APFloat(APInt(64, Record[0])));
752      else if (CurTy == Type::X86_FP80Ty)
753        V = ConstantFP::get(APFloat(APInt(80, 2, &Record[0])));
754      else if (CurTy == Type::FP128Ty)
755        V = ConstantFP::get(APFloat(APInt(128, 2, &Record[0]), true));
756      else if (CurTy == Type::PPC_FP128Ty)
757        V = ConstantFP::get(APFloat(APInt(128, 2, &Record[0])));
758      else
759        V = UndefValue::get(CurTy);
760      break;
761    }
762
763    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
764      if (Record.empty())
765        return Error("Invalid CST_AGGREGATE record");
766
767      unsigned Size = Record.size();
768      std::vector<Constant*> Elts;
769
770      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
771        for (unsigned i = 0; i != Size; ++i)
772          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
773                                                     STy->getElementType(i)));
774        V = ConstantStruct::get(STy, Elts);
775      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
776        const Type *EltTy = ATy->getElementType();
777        for (unsigned i = 0; i != Size; ++i)
778          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
779        V = ConstantArray::get(ATy, Elts);
780      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
781        const Type *EltTy = VTy->getElementType();
782        for (unsigned i = 0; i != Size; ++i)
783          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
784        V = ConstantVector::get(Elts);
785      } else {
786        V = UndefValue::get(CurTy);
787      }
788      break;
789    }
790    case bitc::CST_CODE_STRING: { // STRING: [values]
791      if (Record.empty())
792        return Error("Invalid CST_AGGREGATE record");
793
794      const ArrayType *ATy = cast<ArrayType>(CurTy);
795      const Type *EltTy = ATy->getElementType();
796
797      unsigned Size = Record.size();
798      std::vector<Constant*> Elts;
799      for (unsigned i = 0; i != Size; ++i)
800        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
801      V = ConstantArray::get(ATy, Elts);
802      break;
803    }
804    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
805      if (Record.empty())
806        return Error("Invalid CST_AGGREGATE record");
807
808      const ArrayType *ATy = cast<ArrayType>(CurTy);
809      const Type *EltTy = ATy->getElementType();
810
811      unsigned Size = Record.size();
812      std::vector<Constant*> Elts;
813      for (unsigned i = 0; i != Size; ++i)
814        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
815      Elts.push_back(Constant::getNullValue(EltTy));
816      V = ConstantArray::get(ATy, Elts);
817      break;
818    }
819    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
820      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
821      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
822      if (Opc < 0) {
823        V = UndefValue::get(CurTy);  // Unknown binop.
824      } else {
825        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
826        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
827        V = ConstantExpr::get(Opc, LHS, RHS);
828      }
829      break;
830    }
831    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
832      if (Record.size() < 3) return Error("Invalid CE_CAST record");
833      int Opc = GetDecodedCastOpcode(Record[0]);
834      if (Opc < 0) {
835        V = UndefValue::get(CurTy);  // Unknown cast.
836      } else {
837        const Type *OpTy = getTypeByID(Record[1]);
838        if (!OpTy) return Error("Invalid CE_CAST record");
839        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
840        V = ConstantExpr::getCast(Opc, Op, CurTy);
841      }
842      break;
843    }
844    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
845      if (Record.size() & 1) return Error("Invalid CE_GEP record");
846      SmallVector<Constant*, 16> Elts;
847      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
848        const Type *ElTy = getTypeByID(Record[i]);
849        if (!ElTy) return Error("Invalid CE_GEP record");
850        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
851      }
852      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1], Elts.size()-1);
853      break;
854    }
855    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
856      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
857      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
858                                                              Type::Int1Ty),
859                                  ValueList.getConstantFwdRef(Record[1],CurTy),
860                                  ValueList.getConstantFwdRef(Record[2],CurTy));
861      break;
862    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
863      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
864      const VectorType *OpTy =
865        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
866      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
867      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
868      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
869                                                  OpTy->getElementType());
870      V = ConstantExpr::getExtractElement(Op0, Op1);
871      break;
872    }
873    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
874      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
875      if (Record.size() < 3 || OpTy == 0)
876        return Error("Invalid CE_INSERTELT record");
877      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
878      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
879                                                  OpTy->getElementType());
880      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
881      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
882      break;
883    }
884    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
885      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
886      if (Record.size() < 3 || OpTy == 0)
887        return Error("Invalid CE_INSERTELT record");
888      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
889      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
890      const Type *ShufTy=VectorType::get(Type::Int32Ty, OpTy->getNumElements());
891      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
892      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
893      break;
894    }
895    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
896      if (Record.size() < 4) return Error("Invalid CE_CMP record");
897      const Type *OpTy = getTypeByID(Record[0]);
898      if (OpTy == 0) return Error("Invalid CE_CMP record");
899      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
900      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
901
902      if (OpTy->isFloatingPoint())
903        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
904      else if (!isa<VectorType>(OpTy))
905        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
906      else if (OpTy->isFPOrFPVector())
907        V = ConstantExpr::getVFCmp(Record[3], Op0, Op1);
908      else
909        V = ConstantExpr::getVICmp(Record[3], Op0, Op1);
910      break;
911    }
912    case bitc::CST_CODE_INLINEASM: {
913      if (Record.size() < 2) return Error("Invalid INLINEASM record");
914      std::string AsmStr, ConstrStr;
915      bool HasSideEffects = Record[0];
916      unsigned AsmStrSize = Record[1];
917      if (2+AsmStrSize >= Record.size())
918        return Error("Invalid INLINEASM record");
919      unsigned ConstStrSize = Record[2+AsmStrSize];
920      if (3+AsmStrSize+ConstStrSize > Record.size())
921        return Error("Invalid INLINEASM record");
922
923      for (unsigned i = 0; i != AsmStrSize; ++i)
924        AsmStr += (char)Record[2+i];
925      for (unsigned i = 0; i != ConstStrSize; ++i)
926        ConstrStr += (char)Record[3+AsmStrSize+i];
927      const PointerType *PTy = cast<PointerType>(CurTy);
928      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
929                         AsmStr, ConstrStr, HasSideEffects);
930      break;
931    }
932    }
933
934    ValueList.AssignValue(V, NextCstNo);
935    ++NextCstNo;
936  }
937
938  if (NextCstNo != ValueList.size())
939    return Error("Invalid constant reference!");
940
941  if (Stream.ReadBlockEnd())
942    return Error("Error at end of constants block");
943
944  // Once all the constants have been read, go through and resolve forward
945  // references.
946  ValueList.ResolveConstantForwardRefs();
947  return false;
948}
949
950/// RememberAndSkipFunctionBody - When we see the block for a function body,
951/// remember where it is and then skip it.  This lets us lazily deserialize the
952/// functions.
953bool BitcodeReader::RememberAndSkipFunctionBody() {
954  // Get the function we are talking about.
955  if (FunctionsWithBodies.empty())
956    return Error("Insufficient function protos");
957
958  Function *Fn = FunctionsWithBodies.back();
959  FunctionsWithBodies.pop_back();
960
961  // Save the current stream state.
962  uint64_t CurBit = Stream.GetCurrentBitNo();
963  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
964
965  // Set the functions linkage to GhostLinkage so we know it is lazily
966  // deserialized.
967  Fn->setLinkage(GlobalValue::GhostLinkage);
968
969  // Skip over the function block for now.
970  if (Stream.SkipBlock())
971    return Error("Malformed block record");
972  return false;
973}
974
975bool BitcodeReader::ParseModule(const std::string &ModuleID) {
976  // Reject multiple MODULE_BLOCK's in a single bitstream.
977  if (TheModule)
978    return Error("Multiple MODULE_BLOCKs in same stream");
979
980  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
981    return Error("Malformed block record");
982
983  // Otherwise, create the module.
984  TheModule = new Module(ModuleID);
985
986  SmallVector<uint64_t, 64> Record;
987  std::vector<std::string> SectionTable;
988  std::vector<std::string> GCTable;
989
990  // Read all the records for this module.
991  while (!Stream.AtEndOfStream()) {
992    unsigned Code = Stream.ReadCode();
993    if (Code == bitc::END_BLOCK) {
994      if (Stream.ReadBlockEnd())
995        return Error("Error at end of module block");
996
997      // Patch the initializers for globals and aliases up.
998      ResolveGlobalAndAliasInits();
999      if (!GlobalInits.empty() || !AliasInits.empty())
1000        return Error("Malformed global initializer set");
1001      if (!FunctionsWithBodies.empty())
1002        return Error("Too few function bodies found");
1003
1004      // Look for intrinsic functions which need to be upgraded at some point
1005      for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
1006           FI != FE; ++FI) {
1007        Function* NewFn;
1008        if (UpgradeIntrinsicFunction(FI, NewFn))
1009          UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
1010      }
1011
1012      // Force deallocation of memory for these vectors to favor the client that
1013      // want lazy deserialization.
1014      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
1015      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
1016      std::vector<Function*>().swap(FunctionsWithBodies);
1017      return false;
1018    }
1019
1020    if (Code == bitc::ENTER_SUBBLOCK) {
1021      switch (Stream.ReadSubBlockID()) {
1022      default:  // Skip unknown content.
1023        if (Stream.SkipBlock())
1024          return Error("Malformed block record");
1025        break;
1026      case bitc::BLOCKINFO_BLOCK_ID:
1027        if (Stream.ReadBlockInfoBlock())
1028          return Error("Malformed BlockInfoBlock");
1029        break;
1030      case bitc::PARAMATTR_BLOCK_ID:
1031        if (ParseParamAttrBlock())
1032          return true;
1033        break;
1034      case bitc::TYPE_BLOCK_ID:
1035        if (ParseTypeTable())
1036          return true;
1037        break;
1038      case bitc::TYPE_SYMTAB_BLOCK_ID:
1039        if (ParseTypeSymbolTable())
1040          return true;
1041        break;
1042      case bitc::VALUE_SYMTAB_BLOCK_ID:
1043        if (ParseValueSymbolTable())
1044          return true;
1045        break;
1046      case bitc::CONSTANTS_BLOCK_ID:
1047        if (ParseConstants() || ResolveGlobalAndAliasInits())
1048          return true;
1049        break;
1050      case bitc::FUNCTION_BLOCK_ID:
1051        // If this is the first function body we've seen, reverse the
1052        // FunctionsWithBodies list.
1053        if (!HasReversedFunctionsWithBodies) {
1054          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
1055          HasReversedFunctionsWithBodies = true;
1056        }
1057
1058        if (RememberAndSkipFunctionBody())
1059          return true;
1060        break;
1061      }
1062      continue;
1063    }
1064
1065    if (Code == bitc::DEFINE_ABBREV) {
1066      Stream.ReadAbbrevRecord();
1067      continue;
1068    }
1069
1070    // Read a record.
1071    switch (Stream.ReadRecord(Code, Record)) {
1072    default: break;  // Default behavior, ignore unknown content.
1073    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
1074      if (Record.size() < 1)
1075        return Error("Malformed MODULE_CODE_VERSION");
1076      // Only version #0 is supported so far.
1077      if (Record[0] != 0)
1078        return Error("Unknown bitstream version!");
1079      break;
1080    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1081      std::string S;
1082      if (ConvertToString(Record, 0, S))
1083        return Error("Invalid MODULE_CODE_TRIPLE record");
1084      TheModule->setTargetTriple(S);
1085      break;
1086    }
1087    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
1088      std::string S;
1089      if (ConvertToString(Record, 0, S))
1090        return Error("Invalid MODULE_CODE_DATALAYOUT record");
1091      TheModule->setDataLayout(S);
1092      break;
1093    }
1094    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
1095      std::string S;
1096      if (ConvertToString(Record, 0, S))
1097        return Error("Invalid MODULE_CODE_ASM record");
1098      TheModule->setModuleInlineAsm(S);
1099      break;
1100    }
1101    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
1102      std::string S;
1103      if (ConvertToString(Record, 0, S))
1104        return Error("Invalid MODULE_CODE_DEPLIB record");
1105      TheModule->addLibrary(S);
1106      break;
1107    }
1108    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
1109      std::string S;
1110      if (ConvertToString(Record, 0, S))
1111        return Error("Invalid MODULE_CODE_SECTIONNAME record");
1112      SectionTable.push_back(S);
1113      break;
1114    }
1115    case bitc::MODULE_CODE_GCNAME: {  // SECTIONNAME: [strchr x N]
1116      std::string S;
1117      if (ConvertToString(Record, 0, S))
1118        return Error("Invalid MODULE_CODE_GCNAME record");
1119      GCTable.push_back(S);
1120      break;
1121    }
1122    // GLOBALVAR: [pointer type, isconst, initid,
1123    //             linkage, alignment, section, visibility, threadlocal]
1124    case bitc::MODULE_CODE_GLOBALVAR: {
1125      if (Record.size() < 6)
1126        return Error("Invalid MODULE_CODE_GLOBALVAR record");
1127      const Type *Ty = getTypeByID(Record[0]);
1128      if (!isa<PointerType>(Ty))
1129        return Error("Global not a pointer type!");
1130      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
1131      Ty = cast<PointerType>(Ty)->getElementType();
1132
1133      bool isConstant = Record[1];
1134      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1135      unsigned Alignment = (1 << Record[4]) >> 1;
1136      std::string Section;
1137      if (Record[5]) {
1138        if (Record[5]-1 >= SectionTable.size())
1139          return Error("Invalid section ID");
1140        Section = SectionTable[Record[5]-1];
1141      }
1142      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1143      if (Record.size() > 6)
1144        Visibility = GetDecodedVisibility(Record[6]);
1145      bool isThreadLocal = false;
1146      if (Record.size() > 7)
1147        isThreadLocal = Record[7];
1148
1149      GlobalVariable *NewGV =
1150        new GlobalVariable(Ty, isConstant, Linkage, 0, "", TheModule,
1151                           isThreadLocal, AddressSpace);
1152      NewGV->setAlignment(Alignment);
1153      if (!Section.empty())
1154        NewGV->setSection(Section);
1155      NewGV->setVisibility(Visibility);
1156      NewGV->setThreadLocal(isThreadLocal);
1157
1158      ValueList.push_back(NewGV);
1159
1160      // Remember which value to use for the global initializer.
1161      if (unsigned InitID = Record[2])
1162        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1163      break;
1164    }
1165    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1166    //             alignment, section, visibility, gc]
1167    case bitc::MODULE_CODE_FUNCTION: {
1168      if (Record.size() < 8)
1169        return Error("Invalid MODULE_CODE_FUNCTION record");
1170      const Type *Ty = getTypeByID(Record[0]);
1171      if (!isa<PointerType>(Ty))
1172        return Error("Function not a pointer type!");
1173      const FunctionType *FTy =
1174        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1175      if (!FTy)
1176        return Error("Function not a pointer to function type!");
1177
1178      Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
1179                                        "", TheModule);
1180
1181      Func->setCallingConv(Record[1]);
1182      bool isProto = Record[2];
1183      Func->setLinkage(GetDecodedLinkage(Record[3]));
1184      Func->setParamAttrs(getParamAttrs(Record[4]));
1185
1186      Func->setAlignment((1 << Record[5]) >> 1);
1187      if (Record[6]) {
1188        if (Record[6]-1 >= SectionTable.size())
1189          return Error("Invalid section ID");
1190        Func->setSection(SectionTable[Record[6]-1]);
1191      }
1192      Func->setVisibility(GetDecodedVisibility(Record[7]));
1193      if (Record.size() > 8 && Record[8]) {
1194        if (Record[8]-1 > GCTable.size())
1195          return Error("Invalid GC ID");
1196        Func->setGC(GCTable[Record[8]-1].c_str());
1197      }
1198
1199      ValueList.push_back(Func);
1200
1201      // If this is a function with a body, remember the prototype we are
1202      // creating now, so that we can match up the body with them later.
1203      if (!isProto)
1204        FunctionsWithBodies.push_back(Func);
1205      break;
1206    }
1207    // ALIAS: [alias type, aliasee val#, linkage]
1208    // ALIAS: [alias type, aliasee val#, linkage, visibility]
1209    case bitc::MODULE_CODE_ALIAS: {
1210      if (Record.size() < 3)
1211        return Error("Invalid MODULE_ALIAS record");
1212      const Type *Ty = getTypeByID(Record[0]);
1213      if (!isa<PointerType>(Ty))
1214        return Error("Function not a pointer type!");
1215
1216      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1217                                           "", 0, TheModule);
1218      // Old bitcode files didn't have visibility field.
1219      if (Record.size() > 3)
1220        NewGA->setVisibility(GetDecodedVisibility(Record[3]));
1221      ValueList.push_back(NewGA);
1222      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1223      break;
1224    }
1225    /// MODULE_CODE_PURGEVALS: [numvals]
1226    case bitc::MODULE_CODE_PURGEVALS:
1227      // Trim down the value list to the specified size.
1228      if (Record.size() < 1 || Record[0] > ValueList.size())
1229        return Error("Invalid MODULE_PURGEVALS record");
1230      ValueList.shrinkTo(Record[0]);
1231      break;
1232    }
1233    Record.clear();
1234  }
1235
1236  return Error("Premature end of bitstream");
1237}
1238
1239/// SkipWrapperHeader - Some systems wrap bc files with a special header for
1240/// padding or other reasons.  The format of this header is:
1241///
1242/// struct bc_header {
1243///   uint32_t Magic;         // 0x0B17C0DE
1244///   uint32_t Version;       // Version, currently always 0.
1245///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1246///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1247///   ... potentially other gunk ...
1248/// };
1249///
1250/// This function is called when we find a file with a matching magic number.
1251/// In this case, skip down to the subsection of the file that is actually a BC
1252/// file.
1253static bool SkipWrapperHeader(unsigned char *&BufPtr, unsigned char *&BufEnd) {
1254  enum {
1255    KnownHeaderSize = 4*4,  // Size of header we read.
1256    OffsetField = 2*4,      // Offset in bytes to Offset field.
1257    SizeField = 3*4         // Offset in bytes to Size field.
1258  };
1259
1260
1261  // Must contain the header!
1262  if (BufEnd-BufPtr < KnownHeaderSize) return true;
1263
1264  unsigned Offset = ( BufPtr[OffsetField  ]        |
1265                     (BufPtr[OffsetField+1] << 8)  |
1266                     (BufPtr[OffsetField+2] << 16) |
1267                     (BufPtr[OffsetField+3] << 24));
1268  unsigned Size   = ( BufPtr[SizeField    ]        |
1269                     (BufPtr[SizeField  +1] << 8)  |
1270                     (BufPtr[SizeField  +2] << 16) |
1271                     (BufPtr[SizeField  +3] << 24));
1272
1273  // Verify that Offset+Size fits in the file.
1274  if (Offset+Size > unsigned(BufEnd-BufPtr))
1275    return true;
1276  BufPtr += Offset;
1277  BufEnd = BufPtr+Size;
1278  return false;
1279}
1280
1281bool BitcodeReader::ParseBitcode() {
1282  TheModule = 0;
1283
1284  if (Buffer->getBufferSize() & 3)
1285    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1286
1287  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1288  unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
1289
1290  // If we have a wrapper header, parse it and ignore the non-bc file contents.
1291  // The magic number is 0x0B17C0DE stored in little endian.
1292  if (BufPtr != BufEnd && BufPtr[0] == 0xDE && BufPtr[1] == 0xC0 &&
1293      BufPtr[2] == 0x17 && BufPtr[3] == 0x0B)
1294    if (SkipWrapperHeader(BufPtr, BufEnd))
1295      return Error("Invalid bitcode wrapper header");
1296
1297  Stream.init(BufPtr, BufEnd);
1298
1299  // Sniff for the signature.
1300  if (Stream.Read(8) != 'B' ||
1301      Stream.Read(8) != 'C' ||
1302      Stream.Read(4) != 0x0 ||
1303      Stream.Read(4) != 0xC ||
1304      Stream.Read(4) != 0xE ||
1305      Stream.Read(4) != 0xD)
1306    return Error("Invalid bitcode signature");
1307
1308  // We expect a number of well-defined blocks, though we don't necessarily
1309  // need to understand them all.
1310  while (!Stream.AtEndOfStream()) {
1311    unsigned Code = Stream.ReadCode();
1312
1313    if (Code != bitc::ENTER_SUBBLOCK)
1314      return Error("Invalid record at top-level");
1315
1316    unsigned BlockID = Stream.ReadSubBlockID();
1317
1318    // We only know the MODULE subblock ID.
1319    switch (BlockID) {
1320    case bitc::BLOCKINFO_BLOCK_ID:
1321      if (Stream.ReadBlockInfoBlock())
1322        return Error("Malformed BlockInfoBlock");
1323      break;
1324    case bitc::MODULE_BLOCK_ID:
1325      if (ParseModule(Buffer->getBufferIdentifier()))
1326        return true;
1327      break;
1328    default:
1329      if (Stream.SkipBlock())
1330        return Error("Malformed block record");
1331      break;
1332    }
1333  }
1334
1335  return false;
1336}
1337
1338
1339/// ParseFunctionBody - Lazily parse the specified function body block.
1340bool BitcodeReader::ParseFunctionBody(Function *F) {
1341  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1342    return Error("Malformed block record");
1343
1344  unsigned ModuleValueListSize = ValueList.size();
1345
1346  // Add all the function arguments to the value table.
1347  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1348    ValueList.push_back(I);
1349
1350  unsigned NextValueNo = ValueList.size();
1351  BasicBlock *CurBB = 0;
1352  unsigned CurBBNo = 0;
1353
1354  // Read all the records.
1355  SmallVector<uint64_t, 64> Record;
1356  while (1) {
1357    unsigned Code = Stream.ReadCode();
1358    if (Code == bitc::END_BLOCK) {
1359      if (Stream.ReadBlockEnd())
1360        return Error("Error at end of function block");
1361      break;
1362    }
1363
1364    if (Code == bitc::ENTER_SUBBLOCK) {
1365      switch (Stream.ReadSubBlockID()) {
1366      default:  // Skip unknown content.
1367        if (Stream.SkipBlock())
1368          return Error("Malformed block record");
1369        break;
1370      case bitc::CONSTANTS_BLOCK_ID:
1371        if (ParseConstants()) return true;
1372        NextValueNo = ValueList.size();
1373        break;
1374      case bitc::VALUE_SYMTAB_BLOCK_ID:
1375        if (ParseValueSymbolTable()) return true;
1376        break;
1377      }
1378      continue;
1379    }
1380
1381    if (Code == bitc::DEFINE_ABBREV) {
1382      Stream.ReadAbbrevRecord();
1383      continue;
1384    }
1385
1386    // Read a record.
1387    Record.clear();
1388    Instruction *I = 0;
1389    switch (Stream.ReadRecord(Code, Record)) {
1390    default: // Default behavior: reject
1391      return Error("Unknown instruction");
1392    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1393      if (Record.size() < 1 || Record[0] == 0)
1394        return Error("Invalid DECLAREBLOCKS record");
1395      // Create all the basic blocks for the function.
1396      FunctionBBs.resize(Record[0]);
1397      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1398        FunctionBBs[i] = BasicBlock::Create("", F);
1399      CurBB = FunctionBBs[0];
1400      continue;
1401
1402    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1403      unsigned OpNum = 0;
1404      Value *LHS, *RHS;
1405      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1406          getValue(Record, OpNum, LHS->getType(), RHS) ||
1407          OpNum+1 != Record.size())
1408        return Error("Invalid BINOP record");
1409
1410      int Opc = GetDecodedBinaryOpcode(Record[OpNum], LHS->getType());
1411      if (Opc == -1) return Error("Invalid BINOP record");
1412      I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
1413      break;
1414    }
1415    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
1416      unsigned OpNum = 0;
1417      Value *Op;
1418      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1419          OpNum+2 != Record.size())
1420        return Error("Invalid CAST record");
1421
1422      const Type *ResTy = getTypeByID(Record[OpNum]);
1423      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
1424      if (Opc == -1 || ResTy == 0)
1425        return Error("Invalid CAST record");
1426      I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
1427      break;
1428    }
1429    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
1430      unsigned OpNum = 0;
1431      Value *BasePtr;
1432      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
1433        return Error("Invalid GEP record");
1434
1435      SmallVector<Value*, 16> GEPIdx;
1436      while (OpNum != Record.size()) {
1437        Value *Op;
1438        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1439          return Error("Invalid GEP record");
1440        GEPIdx.push_back(Op);
1441      }
1442
1443      I = GetElementPtrInst::Create(BasePtr, GEPIdx.begin(), GEPIdx.end());
1444      break;
1445    }
1446
1447    case bitc::FUNC_CODE_INST_EXTRACTVAL: {
1448                                       // EXTRACTVAL: [opty, opval, n x indices]
1449      unsigned OpNum = 0;
1450      Value *Agg;
1451      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
1452        return Error("Invalid EXTRACTVAL record");
1453
1454      SmallVector<unsigned, 4> EXTRACTVALIdx;
1455      for (unsigned RecSize = Record.size();
1456           OpNum != RecSize; ++OpNum) {
1457        uint64_t Index = Record[OpNum];
1458        if ((unsigned)Index != Index)
1459          return Error("Invalid EXTRACTVAL index");
1460        EXTRACTVALIdx.push_back((unsigned)Index);
1461      }
1462
1463      I = ExtractValueInst::Create(Agg,
1464                                   EXTRACTVALIdx.begin(), EXTRACTVALIdx.end());
1465      break;
1466    }
1467
1468    case bitc::FUNC_CODE_INST_INSERTVAL: {
1469                           // INSERTVAL: [opty, opval, opty, opval, n x indices]
1470      unsigned OpNum = 0;
1471      Value *Agg;
1472      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
1473        return Error("Invalid INSERTVAL record");
1474      Value *Val;
1475      if (getValueTypePair(Record, OpNum, NextValueNo, Val))
1476        return Error("Invalid INSERTVAL record");
1477
1478      SmallVector<unsigned, 4> INSERTVALIdx;
1479      for (unsigned RecSize = Record.size();
1480           OpNum != RecSize; ++OpNum) {
1481        uint64_t Index = Record[OpNum];
1482        if ((unsigned)Index != Index)
1483          return Error("Invalid INSERTVAL index");
1484        INSERTVALIdx.push_back((unsigned)Index);
1485      }
1486
1487      I = InsertValueInst::Create(Agg, Val,
1488                                  INSERTVALIdx.begin(), INSERTVALIdx.end());
1489      break;
1490    }
1491
1492    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
1493      unsigned OpNum = 0;
1494      Value *TrueVal, *FalseVal, *Cond;
1495      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
1496          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
1497          getValue(Record, OpNum, Type::Int1Ty, Cond))
1498        return Error("Invalid SELECT record");
1499
1500      I = SelectInst::Create(Cond, TrueVal, FalseVal);
1501      break;
1502    }
1503
1504    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1505      unsigned OpNum = 0;
1506      Value *Vec, *Idx;
1507      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1508          getValue(Record, OpNum, Type::Int32Ty, Idx))
1509        return Error("Invalid EXTRACTELT record");
1510      I = new ExtractElementInst(Vec, Idx);
1511      break;
1512    }
1513
1514    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1515      unsigned OpNum = 0;
1516      Value *Vec, *Elt, *Idx;
1517      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1518          getValue(Record, OpNum,
1519                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
1520          getValue(Record, OpNum, Type::Int32Ty, Idx))
1521        return Error("Invalid INSERTELT record");
1522      I = InsertElementInst::Create(Vec, Elt, Idx);
1523      break;
1524    }
1525
1526    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
1527      unsigned OpNum = 0;
1528      Value *Vec1, *Vec2, *Mask;
1529      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
1530          getValue(Record, OpNum, Vec1->getType(), Vec2))
1531        return Error("Invalid SHUFFLEVEC record");
1532
1533      const Type *MaskTy =
1534        VectorType::get(Type::Int32Ty,
1535                        cast<VectorType>(Vec1->getType())->getNumElements());
1536
1537      if (getValue(Record, OpNum, MaskTy, Mask))
1538        return Error("Invalid SHUFFLEVEC record");
1539      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1540      break;
1541    }
1542
1543    case bitc::FUNC_CODE_INST_CMP: { // CMP: [opty, opval, opval, pred]
1544      unsigned OpNum = 0;
1545      Value *LHS, *RHS;
1546      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1547          getValue(Record, OpNum, LHS->getType(), RHS) ||
1548          OpNum+1 != Record.size())
1549        return Error("Invalid CMP record");
1550
1551      if (LHS->getType()->isFloatingPoint())
1552        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1553      else if (!isa<VectorType>(LHS->getType()))
1554        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1555      else if (LHS->getType()->isFPOrFPVector())
1556        I = new VFCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1557      else
1558        I = new VICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1559      break;
1560    }
1561    case bitc::FUNC_CODE_INST_GETRESULT: { // GETRESULT: [ty, val, n]
1562      if (Record.size() != 2)
1563        return Error("Invalid GETRESULT record");
1564      unsigned OpNum = 0;
1565      Value *Op;
1566      getValueTypePair(Record, OpNum, NextValueNo, Op);
1567      unsigned Index = Record[1];
1568      I = ExtractValueInst::Create(Op, Index);
1569      break;
1570    }
1571
1572    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1573      {
1574        unsigned Size = Record.size();
1575        if (Size == 0) {
1576          I = ReturnInst::Create();
1577          break;
1578        }
1579
1580        unsigned OpNum = 0;
1581        SmallVector<Value *,4> Vs;
1582        do {
1583          Value *Op = NULL;
1584          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1585            return Error("Invalid RET record");
1586          Vs.push_back(Op);
1587        } while(OpNum != Record.size());
1588
1589        const Type *ReturnType = F->getReturnType();
1590        if (Vs.size() > 1 ||
1591            (isa<StructType>(ReturnType) &&
1592             (Vs.empty() || Vs[0]->getType() != ReturnType))) {
1593          Value *RV = UndefValue::get(ReturnType);
1594          for (unsigned i = 0, e = Vs.size(); i != e; ++i) {
1595            I = InsertValueInst::Create(RV, Vs[i], i, "mrv");
1596            CurBB->getInstList().push_back(I);
1597            ValueList.AssignValue(I, NextValueNo++);
1598            RV = I;
1599          }
1600          I = ReturnInst::Create(RV);
1601          break;
1602        }
1603
1604        I = ReturnInst::Create(Vs[0]);
1605        break;
1606      }
1607    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1608      if (Record.size() != 1 && Record.size() != 3)
1609        return Error("Invalid BR record");
1610      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1611      if (TrueDest == 0)
1612        return Error("Invalid BR record");
1613
1614      if (Record.size() == 1)
1615        I = BranchInst::Create(TrueDest);
1616      else {
1617        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1618        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1619        if (FalseDest == 0 || Cond == 0)
1620          return Error("Invalid BR record");
1621        I = BranchInst::Create(TrueDest, FalseDest, Cond);
1622      }
1623      break;
1624    }
1625    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1626      if (Record.size() < 3 || (Record.size() & 1) == 0)
1627        return Error("Invalid SWITCH record");
1628      const Type *OpTy = getTypeByID(Record[0]);
1629      Value *Cond = getFnValueByID(Record[1], OpTy);
1630      BasicBlock *Default = getBasicBlock(Record[2]);
1631      if (OpTy == 0 || Cond == 0 || Default == 0)
1632        return Error("Invalid SWITCH record");
1633      unsigned NumCases = (Record.size()-3)/2;
1634      SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
1635      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1636        ConstantInt *CaseVal =
1637          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1638        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1639        if (CaseVal == 0 || DestBB == 0) {
1640          delete SI;
1641          return Error("Invalid SWITCH record!");
1642        }
1643        SI->addCase(CaseVal, DestBB);
1644      }
1645      I = SI;
1646      break;
1647    }
1648
1649    case bitc::FUNC_CODE_INST_INVOKE: {
1650      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
1651      if (Record.size() < 4) return Error("Invalid INVOKE record");
1652      PAListPtr PAL = getParamAttrs(Record[0]);
1653      unsigned CCInfo = Record[1];
1654      BasicBlock *NormalBB = getBasicBlock(Record[2]);
1655      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
1656
1657      unsigned OpNum = 4;
1658      Value *Callee;
1659      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1660        return Error("Invalid INVOKE record");
1661
1662      const PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
1663      const FunctionType *FTy = !CalleeTy ? 0 :
1664        dyn_cast<FunctionType>(CalleeTy->getElementType());
1665
1666      // Check that the right number of fixed parameters are here.
1667      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
1668          Record.size() < OpNum+FTy->getNumParams())
1669        return Error("Invalid INVOKE record");
1670
1671      SmallVector<Value*, 16> Ops;
1672      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1673        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1674        if (Ops.back() == 0) return Error("Invalid INVOKE record");
1675      }
1676
1677      if (!FTy->isVarArg()) {
1678        if (Record.size() != OpNum)
1679          return Error("Invalid INVOKE record");
1680      } else {
1681        // Read type/value pairs for varargs params.
1682        while (OpNum != Record.size()) {
1683          Value *Op;
1684          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1685            return Error("Invalid INVOKE record");
1686          Ops.push_back(Op);
1687        }
1688      }
1689
1690      I = InvokeInst::Create(Callee, NormalBB, UnwindBB,
1691                             Ops.begin(), Ops.end());
1692      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1693      cast<InvokeInst>(I)->setParamAttrs(PAL);
1694      break;
1695    }
1696    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1697      I = new UnwindInst();
1698      break;
1699    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1700      I = new UnreachableInst();
1701      break;
1702    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
1703      if (Record.size() < 1 || ((Record.size()-1)&1))
1704        return Error("Invalid PHI record");
1705      const Type *Ty = getTypeByID(Record[0]);
1706      if (!Ty) return Error("Invalid PHI record");
1707
1708      PHINode *PN = PHINode::Create(Ty);
1709      PN->reserveOperandSpace((Record.size()-1)/2);
1710
1711      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
1712        Value *V = getFnValueByID(Record[1+i], Ty);
1713        BasicBlock *BB = getBasicBlock(Record[2+i]);
1714        if (!V || !BB) return Error("Invalid PHI record");
1715        PN->addIncoming(V, BB);
1716      }
1717      I = PN;
1718      break;
1719    }
1720
1721    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1722      if (Record.size() < 3)
1723        return Error("Invalid MALLOC record");
1724      const PointerType *Ty =
1725        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1726      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1727      unsigned Align = Record[2];
1728      if (!Ty || !Size) return Error("Invalid MALLOC record");
1729      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1730      break;
1731    }
1732    case bitc::FUNC_CODE_INST_FREE: { // FREE: [op, opty]
1733      unsigned OpNum = 0;
1734      Value *Op;
1735      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1736          OpNum != Record.size())
1737        return Error("Invalid FREE record");
1738      I = new FreeInst(Op);
1739      break;
1740    }
1741    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1742      if (Record.size() < 3)
1743        return Error("Invalid ALLOCA record");
1744      const PointerType *Ty =
1745        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1746      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1747      unsigned Align = Record[2];
1748      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1749      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1750      break;
1751    }
1752    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1753      unsigned OpNum = 0;
1754      Value *Op;
1755      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1756          OpNum+2 != Record.size())
1757        return Error("Invalid LOAD record");
1758
1759      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1760      break;
1761    }
1762    case bitc::FUNC_CODE_INST_STORE2: { // STORE2:[ptrty, ptr, val, align, vol]
1763      unsigned OpNum = 0;
1764      Value *Val, *Ptr;
1765      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
1766          getValue(Record, OpNum,
1767                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
1768          OpNum+2 != Record.size())
1769        return Error("Invalid STORE record");
1770
1771      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1772      break;
1773    }
1774    case bitc::FUNC_CODE_INST_STORE: { // STORE:[val, valty, ptr, align, vol]
1775      // FIXME: Legacy form of store instruction. Should be removed in LLVM 3.0.
1776      unsigned OpNum = 0;
1777      Value *Val, *Ptr;
1778      if (getValueTypePair(Record, OpNum, NextValueNo, Val) ||
1779          getValue(Record, OpNum, PointerType::getUnqual(Val->getType()), Ptr)||
1780          OpNum+2 != Record.size())
1781        return Error("Invalid STORE record");
1782
1783      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1784      break;
1785    }
1786    case bitc::FUNC_CODE_INST_CALL: {
1787      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
1788      if (Record.size() < 3)
1789        return Error("Invalid CALL record");
1790
1791      PAListPtr PAL = getParamAttrs(Record[0]);
1792      unsigned CCInfo = Record[1];
1793
1794      unsigned OpNum = 2;
1795      Value *Callee;
1796      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1797        return Error("Invalid CALL record");
1798
1799      const PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
1800      const FunctionType *FTy = 0;
1801      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1802      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
1803        return Error("Invalid CALL record");
1804
1805      SmallVector<Value*, 16> Args;
1806      // Read the fixed params.
1807      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1808        if (FTy->getParamType(i)->getTypeID()==Type::LabelTyID)
1809          Args.push_back(getBasicBlock(Record[OpNum]));
1810        else
1811          Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1812        if (Args.back() == 0) return Error("Invalid CALL record");
1813      }
1814
1815      // Read type/value pairs for varargs params.
1816      if (!FTy->isVarArg()) {
1817        if (OpNum != Record.size())
1818          return Error("Invalid CALL record");
1819      } else {
1820        while (OpNum != Record.size()) {
1821          Value *Op;
1822          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1823            return Error("Invalid CALL record");
1824          Args.push_back(Op);
1825        }
1826      }
1827
1828      I = CallInst::Create(Callee, Args.begin(), Args.end());
1829      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
1830      cast<CallInst>(I)->setTailCall(CCInfo & 1);
1831      cast<CallInst>(I)->setParamAttrs(PAL);
1832      break;
1833    }
1834    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
1835      if (Record.size() < 3)
1836        return Error("Invalid VAARG record");
1837      const Type *OpTy = getTypeByID(Record[0]);
1838      Value *Op = getFnValueByID(Record[1], OpTy);
1839      const Type *ResTy = getTypeByID(Record[2]);
1840      if (!OpTy || !Op || !ResTy)
1841        return Error("Invalid VAARG record");
1842      I = new VAArgInst(Op, ResTy);
1843      break;
1844    }
1845    }
1846
1847    // Add instruction to end of current BB.  If there is no current BB, reject
1848    // this file.
1849    if (CurBB == 0) {
1850      delete I;
1851      return Error("Invalid instruction with no BB");
1852    }
1853    CurBB->getInstList().push_back(I);
1854
1855    // If this was a terminator instruction, move to the next block.
1856    if (isa<TerminatorInst>(I)) {
1857      ++CurBBNo;
1858      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
1859    }
1860
1861    // Non-void values get registered in the value table for future use.
1862    if (I && I->getType() != Type::VoidTy)
1863      ValueList.AssignValue(I, NextValueNo++);
1864  }
1865
1866  // Check the function list for unresolved values.
1867  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
1868    if (A->getParent() == 0) {
1869      // We found at least one unresolved value.  Nuke them all to avoid leaks.
1870      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
1871        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
1872          A->replaceAllUsesWith(UndefValue::get(A->getType()));
1873          delete A;
1874        }
1875      }
1876      return Error("Never resolved value found in function!");
1877    }
1878  }
1879
1880  // Trim the value list down to the size it was before we parsed this function.
1881  ValueList.shrinkTo(ModuleValueListSize);
1882  std::vector<BasicBlock*>().swap(FunctionBBs);
1883
1884  return false;
1885}
1886
1887//===----------------------------------------------------------------------===//
1888// ModuleProvider implementation
1889//===----------------------------------------------------------------------===//
1890
1891
1892bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
1893  // If it already is material, ignore the request.
1894  if (!F->hasNotBeenReadFromBitcode()) return false;
1895
1896  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
1897    DeferredFunctionInfo.find(F);
1898  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
1899
1900  // Move the bit stream to the saved position of the deferred function body and
1901  // restore the real linkage type for the function.
1902  Stream.JumpToBit(DFII->second.first);
1903  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
1904
1905  if (ParseFunctionBody(F)) {
1906    if (ErrInfo) *ErrInfo = ErrorString;
1907    return true;
1908  }
1909
1910  // Upgrade any old intrinsic calls in the function.
1911  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
1912       E = UpgradedIntrinsics.end(); I != E; ++I) {
1913    if (I->first != I->second) {
1914      for (Value::use_iterator UI = I->first->use_begin(),
1915           UE = I->first->use_end(); UI != UE; ) {
1916        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1917          UpgradeIntrinsicCall(CI, I->second);
1918      }
1919    }
1920  }
1921
1922  return false;
1923}
1924
1925void BitcodeReader::dematerializeFunction(Function *F) {
1926  // If this function isn't materialized, or if it is a proto, this is a noop.
1927  if (F->hasNotBeenReadFromBitcode() || F->isDeclaration())
1928    return;
1929
1930  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
1931
1932  // Just forget the function body, we can remat it later.
1933  F->deleteBody();
1934  F->setLinkage(GlobalValue::GhostLinkage);
1935}
1936
1937
1938Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
1939  for (DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator I =
1940       DeferredFunctionInfo.begin(), E = DeferredFunctionInfo.end(); I != E;
1941       ++I) {
1942    Function *F = I->first;
1943    if (F->hasNotBeenReadFromBitcode() &&
1944        materializeFunction(F, ErrInfo))
1945      return 0;
1946  }
1947
1948  // Upgrade any intrinsic calls that slipped through (should not happen!) and
1949  // delete the old functions to clean up. We can't do this unless the entire
1950  // module is materialized because there could always be another function body
1951  // with calls to the old function.
1952  for (std::vector<std::pair<Function*, Function*> >::iterator I =
1953       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
1954    if (I->first != I->second) {
1955      for (Value::use_iterator UI = I->first->use_begin(),
1956           UE = I->first->use_end(); UI != UE; ) {
1957        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
1958          UpgradeIntrinsicCall(CI, I->second);
1959      }
1960      ValueList.replaceUsesOfWith(I->first, I->second);
1961      I->first->eraseFromParent();
1962    }
1963  }
1964  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
1965
1966  return TheModule;
1967}
1968
1969
1970/// This method is provided by the parent ModuleProvde class and overriden
1971/// here. It simply releases the module from its provided and frees up our
1972/// state.
1973/// @brief Release our hold on the generated module
1974Module *BitcodeReader::releaseModule(std::string *ErrInfo) {
1975  // Since we're losing control of this Module, we must hand it back complete
1976  Module *M = ModuleProvider::releaseModule(ErrInfo);
1977  FreeState();
1978  return M;
1979}
1980
1981
1982//===----------------------------------------------------------------------===//
1983// External interface
1984//===----------------------------------------------------------------------===//
1985
1986/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
1987///
1988ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
1989                                               std::string *ErrMsg) {
1990  BitcodeReader *R = new BitcodeReader(Buffer);
1991  if (R->ParseBitcode()) {
1992    if (ErrMsg)
1993      *ErrMsg = R->getErrorString();
1994
1995    // Don't let the BitcodeReader dtor delete 'Buffer'.
1996    R->releaseMemoryBuffer();
1997    delete R;
1998    return 0;
1999  }
2000  return R;
2001}
2002
2003/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
2004/// If an error occurs, return null and fill in *ErrMsg if non-null.
2005Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, std::string *ErrMsg){
2006  BitcodeReader *R;
2007  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, ErrMsg));
2008  if (!R) return 0;
2009
2010  // Read in the entire module.
2011  Module *M = R->materializeModule(ErrMsg);
2012
2013  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
2014  // there was an error.
2015  R->releaseMemoryBuffer();
2016
2017  // If there was no error, tell ModuleProvider not to delete it when its dtor
2018  // is run.
2019  if (M)
2020    M = R->releaseModule(ErrMsg);
2021
2022  delete R;
2023  return M;
2024}
2025