BitcodeReader.cpp revision 647e3016de18d2fc8b0f233a0b356809e3fdcc54 
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/LLVMContext.h"
21#include "llvm/Metadata.h"
22#include "llvm/Module.h"
23#include "llvm/Operator.h"
24#include "llvm/AutoUpgrade.h"
25#include "llvm/ADT/SmallString.h"
26#include "llvm/ADT/SmallVector.h"
27#include "llvm/Support/MathExtras.h"
28#include "llvm/Support/MemoryBuffer.h"
29#include "llvm/OperandTraits.h"
30using namespace llvm;
31
32void BitcodeReader::FreeState() {
33  delete Buffer;
34  Buffer = 0;
35  std::vector<PATypeHolder>().swap(TypeList);
36  ValueList.clear();
37
38  std::vector<AttrListPtr>().swap(MAttributes);
39  std::vector<BasicBlock*>().swap(FunctionBBs);
40  std::vector<Function*>().swap(FunctionsWithBodies);
41  DeferredFunctionInfo.clear();
42}
43
44//===----------------------------------------------------------------------===//
45//  Helper functions to implement forward reference resolution, etc.
46//===----------------------------------------------------------------------===//
47
48/// ConvertToString - Convert a string from a record into an std::string, return
49/// true on failure.
50template<typename StrTy>
51static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
52                            StrTy &Result) {
53  if (Idx > Record.size())
54    return true;
55
56  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
57    Result += (char)Record[i];
58  return false;
59}
60
61static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
62  switch (Val) {
63  default: // Map unknown/new linkages to external
64  case 0:  return GlobalValue::ExternalLinkage;
65  case 1:  return GlobalValue::WeakAnyLinkage;
66  case 2:  return GlobalValue::AppendingLinkage;
67  case 3:  return GlobalValue::InternalLinkage;
68  case 4:  return GlobalValue::LinkOnceAnyLinkage;
69  case 5:  return GlobalValue::DLLImportLinkage;
70  case 6:  return GlobalValue::DLLExportLinkage;
71  case 7:  return GlobalValue::ExternalWeakLinkage;
72  case 8:  return GlobalValue::CommonLinkage;
73  case 9:  return GlobalValue::PrivateLinkage;
74  case 10: return GlobalValue::WeakODRLinkage;
75  case 11: return GlobalValue::LinkOnceODRLinkage;
76  case 12: return GlobalValue::AvailableExternallyLinkage;
77  case 13: return GlobalValue::LinkerPrivateLinkage;
78  }
79}
80
81static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
82  switch (Val) {
83  default: // Map unknown visibilities to default.
84  case 0: return GlobalValue::DefaultVisibility;
85  case 1: return GlobalValue::HiddenVisibility;
86  case 2: return GlobalValue::ProtectedVisibility;
87  }
88}
89
90static int GetDecodedCastOpcode(unsigned Val) {
91  switch (Val) {
92  default: return -1;
93  case bitc::CAST_TRUNC   : return Instruction::Trunc;
94  case bitc::CAST_ZEXT    : return Instruction::ZExt;
95  case bitc::CAST_SEXT    : return Instruction::SExt;
96  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
97  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
98  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
99  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
100  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
101  case bitc::CAST_FPEXT   : return Instruction::FPExt;
102  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
103  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
104  case bitc::CAST_BITCAST : return Instruction::BitCast;
105  }
106}
107static int GetDecodedBinaryOpcode(unsigned Val, const Type *Ty) {
108  switch (Val) {
109  default: return -1;
110  case bitc::BINOP_ADD:
111    return Ty->isFPOrFPVector() ? Instruction::FAdd : Instruction::Add;
112  case bitc::BINOP_SUB:
113    return Ty->isFPOrFPVector() ? Instruction::FSub : Instruction::Sub;
114  case bitc::BINOP_MUL:
115    return Ty->isFPOrFPVector() ? Instruction::FMul : Instruction::Mul;
116  case bitc::BINOP_UDIV: return Instruction::UDiv;
117  case bitc::BINOP_SDIV:
118    return Ty->isFPOrFPVector() ? Instruction::FDiv : Instruction::SDiv;
119  case bitc::BINOP_UREM: return Instruction::URem;
120  case bitc::BINOP_SREM:
121    return Ty->isFPOrFPVector() ? Instruction::FRem : Instruction::SRem;
122  case bitc::BINOP_SHL:  return Instruction::Shl;
123  case bitc::BINOP_LSHR: return Instruction::LShr;
124  case bitc::BINOP_ASHR: return Instruction::AShr;
125  case bitc::BINOP_AND:  return Instruction::And;
126  case bitc::BINOP_OR:   return Instruction::Or;
127  case bitc::BINOP_XOR:  return Instruction::Xor;
128  }
129}
130
131namespace llvm {
132namespace {
133  /// @brief A class for maintaining the slot number definition
134  /// as a placeholder for the actual definition for forward constants defs.
135  class ConstantPlaceHolder : public ConstantExpr {
136    ConstantPlaceHolder();                       // DO NOT IMPLEMENT
137    void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
138  public:
139    // allocate space for exactly one operand
140    void *operator new(size_t s) {
141      return User::operator new(s, 1);
142    }
143    explicit ConstantPlaceHolder(const Type *Ty, LLVMContext& Context)
144      : ConstantExpr(Ty, Instruction::UserOp1, &Op<0>(), 1) {
145      Op<0>() = UndefValue::get(Type::Int32Ty);
146    }
147
148    /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
149    static inline bool classof(const ConstantPlaceHolder *) { return true; }
150    static bool classof(const Value *V) {
151      return isa<ConstantExpr>(V) &&
152             cast<ConstantExpr>(V)->getOpcode() == Instruction::UserOp1;
153    }
154
155
156    /// Provide fast operand accessors
157    //DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
158  };
159}
160
161// FIXME: can we inherit this from ConstantExpr?
162template <>
163struct OperandTraits<ConstantPlaceHolder> : FixedNumOperandTraits<1> {
164};
165}
166
167
168void BitcodeReaderValueList::AssignValue(Value *V, unsigned Idx) {
169  if (Idx == size()) {
170    push_back(V);
171    return;
172  }
173
174  if (Idx >= size())
175    resize(Idx+1);
176
177  WeakVH &OldV = ValuePtrs[Idx];
178  if (OldV == 0) {
179    OldV = V;
180    return;
181  }
182
183  // Handle constants and non-constants (e.g. instrs) differently for
184  // efficiency.
185  if (Constant *PHC = dyn_cast<Constant>(&*OldV)) {
186    ResolveConstants.push_back(std::make_pair(PHC, Idx));
187    OldV = V;
188  } else {
189    // If there was a forward reference to this value, replace it.
190    Value *PrevVal = OldV;
191    OldV->replaceAllUsesWith(V);
192    delete PrevVal;
193  }
194}
195
196
197Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
198                                                    const Type *Ty) {
199  if (Idx >= size())
200    resize(Idx + 1);
201
202  if (Value *V = ValuePtrs[Idx]) {
203    assert(Ty == V->getType() && "Type mismatch in constant table!");
204    return cast<Constant>(V);
205  }
206
207  // Create and return a placeholder, which will later be RAUW'd.
208  Constant *C = new ConstantPlaceHolder(Ty, Context);
209  ValuePtrs[Idx] = C;
210  return C;
211}
212
213Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, const Type *Ty) {
214  if (Idx >= size())
215    resize(Idx + 1);
216
217  if (Value *V = ValuePtrs[Idx]) {
218    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
219    return V;
220  }
221
222  // No type specified, must be invalid reference.
223  if (Ty == 0) return 0;
224
225  // Create and return a placeholder, which will later be RAUW'd.
226  Value *V = new Argument(Ty);
227  ValuePtrs[Idx] = V;
228  return V;
229}
230
231/// ResolveConstantForwardRefs - Once all constants are read, this method bulk
232/// resolves any forward references.  The idea behind this is that we sometimes
233/// get constants (such as large arrays) which reference *many* forward ref
234/// constants.  Replacing each of these causes a lot of thrashing when
235/// building/reuniquing the constant.  Instead of doing this, we look at all the
236/// uses and rewrite all the place holders at once for any constant that uses
237/// a placeholder.
238void BitcodeReaderValueList::ResolveConstantForwardRefs() {
239  // Sort the values by-pointer so that they are efficient to look up with a
240  // binary search.
241  std::sort(ResolveConstants.begin(), ResolveConstants.end());
242
243  SmallVector<Constant*, 64> NewOps;
244
245  while (!ResolveConstants.empty()) {
246    Value *RealVal = operator[](ResolveConstants.back().second);
247    Constant *Placeholder = ResolveConstants.back().first;
248    ResolveConstants.pop_back();
249
250    // Loop over all users of the placeholder, updating them to reference the
251    // new value.  If they reference more than one placeholder, update them all
252    // at once.
253    while (!Placeholder->use_empty()) {
254      Value::use_iterator UI = Placeholder->use_begin();
255
256      // If the using object isn't uniqued, just update the operands.  This
257      // handles instructions and initializers for global variables.
258      if (!isa<Constant>(*UI) || isa<GlobalValue>(*UI)) {
259        UI.getUse().set(RealVal);
260        continue;
261      }
262
263      // Otherwise, we have a constant that uses the placeholder.  Replace that
264      // constant with a new constant that has *all* placeholder uses updated.
265      Constant *UserC = cast<Constant>(*UI);
266      for (User::op_iterator I = UserC->op_begin(), E = UserC->op_end();
267           I != E; ++I) {
268        Value *NewOp;
269        if (!isa<ConstantPlaceHolder>(*I)) {
270          // Not a placeholder reference.
271          NewOp = *I;
272        } else if (*I == Placeholder) {
273          // Common case is that it just references this one placeholder.
274          NewOp = RealVal;
275        } else {
276          // Otherwise, look up the placeholder in ResolveConstants.
277          ResolveConstantsTy::iterator It =
278            std::lower_bound(ResolveConstants.begin(), ResolveConstants.end(),
279                             std::pair<Constant*, unsigned>(cast<Constant>(*I),
280                                                            0));
281          assert(It != ResolveConstants.end() && It->first == *I);
282          NewOp = operator[](It->second);
283        }
284
285        NewOps.push_back(cast<Constant>(NewOp));
286      }
287
288      // Make the new constant.
289      Constant *NewC;
290      if (ConstantArray *UserCA = dyn_cast<ConstantArray>(UserC)) {
291        NewC = ConstantArray::get(UserCA->getType(), &NewOps[0],
292                                        NewOps.size());
293      } else if (ConstantStruct *UserCS = dyn_cast<ConstantStruct>(UserC)) {
294        NewC = ConstantStruct::get(&NewOps[0], NewOps.size(),
295                                         UserCS->getType()->isPacked());
296      } else if (isa<ConstantVector>(UserC)) {
297        NewC = ConstantVector::get(&NewOps[0], NewOps.size());
298      } else {
299        assert(isa<ConstantExpr>(UserC) && "Must be a ConstantExpr.");
300        NewC = cast<ConstantExpr>(UserC)->getWithOperands(&NewOps[0],
301                                                          NewOps.size());
302      }
303
304      UserC->replaceAllUsesWith(NewC);
305      UserC->destroyConstant();
306      NewOps.clear();
307    }
308
309    // Update all ValueHandles, they should be the only users at this point.
310    Placeholder->replaceAllUsesWith(RealVal);
311    delete Placeholder;
312  }
313}
314
315
316const Type *BitcodeReader::getTypeByID(unsigned ID, bool isTypeTable) {
317  // If the TypeID is in range, return it.
318  if (ID < TypeList.size())
319    return TypeList[ID].get();
320  if (!isTypeTable) return 0;
321
322  // The type table allows forward references.  Push as many Opaque types as
323  // needed to get up to ID.
324  while (TypeList.size() <= ID)
325    TypeList.push_back(OpaqueType::get());
326  return TypeList.back().get();
327}
328
329//===----------------------------------------------------------------------===//
330//  Functions for parsing blocks from the bitcode file
331//===----------------------------------------------------------------------===//
332
333bool BitcodeReader::ParseAttributeBlock() {
334  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
335    return Error("Malformed block record");
336
337  if (!MAttributes.empty())
338    return Error("Multiple PARAMATTR blocks found!");
339
340  SmallVector<uint64_t, 64> Record;
341
342  SmallVector<AttributeWithIndex, 8> Attrs;
343
344  // Read all the records.
345  while (1) {
346    unsigned Code = Stream.ReadCode();
347    if (Code == bitc::END_BLOCK) {
348      if (Stream.ReadBlockEnd())
349        return Error("Error at end of PARAMATTR block");
350      return false;
351    }
352
353    if (Code == bitc::ENTER_SUBBLOCK) {
354      // No known subblocks, always skip them.
355      Stream.ReadSubBlockID();
356      if (Stream.SkipBlock())
357        return Error("Malformed block record");
358      continue;
359    }
360
361    if (Code == bitc::DEFINE_ABBREV) {
362      Stream.ReadAbbrevRecord();
363      continue;
364    }
365
366    // Read a record.
367    Record.clear();
368    switch (Stream.ReadRecord(Code, Record)) {
369    default:  // Default behavior: ignore.
370      break;
371    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
372      if (Record.size() & 1)
373        return Error("Invalid ENTRY record");
374
375      // FIXME : Remove this autoupgrade code in LLVM 3.0.
376      // If Function attributes are using index 0 then transfer them
377      // to index ~0. Index 0 is used for return value attributes but used to be
378      // used for function attributes.
379      Attributes RetAttribute = Attribute::None;
380      Attributes FnAttribute = Attribute::None;
381      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
382        // FIXME: remove in LLVM 3.0
383        // The alignment is stored as a 16-bit raw value from bits 31--16.
384        // We shift the bits above 31 down by 11 bits.
385
386        unsigned Alignment = (Record[i+1] & (0xffffull << 16)) >> 16;
387        if (Alignment && !isPowerOf2_32(Alignment))
388          return Error("Alignment is not a power of two.");
389
390        Attributes ReconstitutedAttr = Record[i+1] & 0xffff;
391        if (Alignment)
392          ReconstitutedAttr |= Attribute::constructAlignmentFromInt(Alignment);
393        ReconstitutedAttr |= (Record[i+1] & (0xffffull << 32)) >> 11;
394        Record[i+1] = ReconstitutedAttr;
395
396        if (Record[i] == 0)
397          RetAttribute = Record[i+1];
398        else if (Record[i] == ~0U)
399          FnAttribute = Record[i+1];
400      }
401
402      unsigned OldRetAttrs = (Attribute::NoUnwind|Attribute::NoReturn|
403                              Attribute::ReadOnly|Attribute::ReadNone);
404
405      if (FnAttribute == Attribute::None && RetAttribute != Attribute::None &&
406          (RetAttribute & OldRetAttrs) != 0) {
407        if (FnAttribute == Attribute::None) { // add a slot so they get added.
408          Record.push_back(~0U);
409          Record.push_back(0);
410        }
411
412        FnAttribute  |= RetAttribute & OldRetAttrs;
413        RetAttribute &= ~OldRetAttrs;
414      }
415
416      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
417        if (Record[i] == 0) {
418          if (RetAttribute != Attribute::None)
419            Attrs.push_back(AttributeWithIndex::get(0, RetAttribute));
420        } else if (Record[i] == ~0U) {
421          if (FnAttribute != Attribute::None)
422            Attrs.push_back(AttributeWithIndex::get(~0U, FnAttribute));
423        } else if (Record[i+1] != Attribute::None)
424          Attrs.push_back(AttributeWithIndex::get(Record[i], Record[i+1]));
425      }
426
427      MAttributes.push_back(AttrListPtr::get(Attrs.begin(), Attrs.end()));
428      Attrs.clear();
429      break;
430    }
431    }
432  }
433}
434
435
436bool BitcodeReader::ParseTypeTable() {
437  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID))
438    return Error("Malformed block record");
439
440  if (!TypeList.empty())
441    return Error("Multiple TYPE_BLOCKs found!");
442
443  SmallVector<uint64_t, 64> Record;
444  unsigned NumRecords = 0;
445
446  // Read all the records for this type table.
447  while (1) {
448    unsigned Code = Stream.ReadCode();
449    if (Code == bitc::END_BLOCK) {
450      if (NumRecords != TypeList.size())
451        return Error("Invalid type forward reference in TYPE_BLOCK");
452      if (Stream.ReadBlockEnd())
453        return Error("Error at end of type table block");
454      return false;
455    }
456
457    if (Code == bitc::ENTER_SUBBLOCK) {
458      // No known subblocks, always skip them.
459      Stream.ReadSubBlockID();
460      if (Stream.SkipBlock())
461        return Error("Malformed block record");
462      continue;
463    }
464
465    if (Code == bitc::DEFINE_ABBREV) {
466      Stream.ReadAbbrevRecord();
467      continue;
468    }
469
470    // Read a record.
471    Record.clear();
472    const Type *ResultTy = 0;
473    switch (Stream.ReadRecord(Code, Record)) {
474    default:  // Default behavior: unknown type.
475      ResultTy = 0;
476      break;
477    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
478      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
479      // type list.  This allows us to reserve space.
480      if (Record.size() < 1)
481        return Error("Invalid TYPE_CODE_NUMENTRY record");
482      TypeList.reserve(Record[0]);
483      continue;
484    case bitc::TYPE_CODE_VOID:      // VOID
485      ResultTy = Type::VoidTy;
486      break;
487    case bitc::TYPE_CODE_FLOAT:     // FLOAT
488      ResultTy = Type::FloatTy;
489      break;
490    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
491      ResultTy = Type::DoubleTy;
492      break;
493    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
494      ResultTy = Type::X86_FP80Ty;
495      break;
496    case bitc::TYPE_CODE_FP128:     // FP128
497      ResultTy = Type::FP128Ty;
498      break;
499    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
500      ResultTy = Type::PPC_FP128Ty;
501      break;
502    case bitc::TYPE_CODE_LABEL:     // LABEL
503      ResultTy = Type::LabelTy;
504      break;
505    case bitc::TYPE_CODE_OPAQUE:    // OPAQUE
506      ResultTy = 0;
507      break;
508    case bitc::TYPE_CODE_METADATA:  // METADATA
509      ResultTy = Type::MetadataTy;
510      break;
511    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
512      if (Record.size() < 1)
513        return Error("Invalid Integer type record");
514
515      ResultTy = IntegerType::get(Record[0]);
516      break;
517    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
518                                    //          [pointee type, address space]
519      if (Record.size() < 1)
520        return Error("Invalid POINTER type record");
521      unsigned AddressSpace = 0;
522      if (Record.size() == 2)
523        AddressSpace = Record[1];
524      ResultTy = PointerType::get(getTypeByID(Record[0], true),
525                                        AddressSpace);
526      break;
527    }
528    case bitc::TYPE_CODE_FUNCTION: {
529      // FIXME: attrid is dead, remove it in LLVM 3.0
530      // FUNCTION: [vararg, attrid, retty, paramty x N]
531      if (Record.size() < 3)
532        return Error("Invalid FUNCTION type record");
533      std::vector<const Type*> ArgTys;
534      for (unsigned i = 3, e = Record.size(); i != e; ++i)
535        ArgTys.push_back(getTypeByID(Record[i], true));
536
537      ResultTy = FunctionType::get(getTypeByID(Record[2], true), ArgTys,
538                                   Record[0]);
539      break;
540    }
541    case bitc::TYPE_CODE_STRUCT: {  // STRUCT: [ispacked, eltty x N]
542      if (Record.size() < 1)
543        return Error("Invalid STRUCT type record");
544      std::vector<const Type*> EltTys;
545      for (unsigned i = 1, e = Record.size(); i != e; ++i)
546        EltTys.push_back(getTypeByID(Record[i], true));
547      ResultTy = StructType::get(EltTys, Record[0]);
548      break;
549    }
550    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
551      if (Record.size() < 2)
552        return Error("Invalid ARRAY type record");
553      ResultTy = ArrayType::get(getTypeByID(Record[1], true), Record[0]);
554      break;
555    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
556      if (Record.size() < 2)
557        return Error("Invalid VECTOR type record");
558      ResultTy = VectorType::get(getTypeByID(Record[1], true), Record[0]);
559      break;
560    }
561
562    if (NumRecords == TypeList.size()) {
563      // If this is a new type slot, just append it.
564      TypeList.push_back(ResultTy ? ResultTy : OpaqueType::get());
565      ++NumRecords;
566    } else if (ResultTy == 0) {
567      // Otherwise, this was forward referenced, so an opaque type was created,
568      // but the result type is actually just an opaque.  Leave the one we
569      // created previously.
570      ++NumRecords;
571    } else {
572      // Otherwise, this was forward referenced, so an opaque type was created.
573      // Resolve the opaque type to the real type now.
574      assert(NumRecords < TypeList.size() && "Typelist imbalance");
575      const OpaqueType *OldTy = cast<OpaqueType>(TypeList[NumRecords++].get());
576
577      // Don't directly push the new type on the Tab. Instead we want to replace
578      // the opaque type we previously inserted with the new concrete value. The
579      // refinement from the abstract (opaque) type to the new type causes all
580      // uses of the abstract type to use the concrete type (NewTy). This will
581      // also cause the opaque type to be deleted.
582      const_cast<OpaqueType*>(OldTy)->refineAbstractTypeTo(ResultTy);
583
584      // This should have replaced the old opaque type with the new type in the
585      // value table... or with a preexisting type that was already in the
586      // system.  Let's just make sure it did.
587      assert(TypeList[NumRecords-1].get() != OldTy &&
588             "refineAbstractType didn't work!");
589    }
590  }
591}
592
593
594bool BitcodeReader::ParseTypeSymbolTable() {
595  if (Stream.EnterSubBlock(bitc::TYPE_SYMTAB_BLOCK_ID))
596    return Error("Malformed block record");
597
598  SmallVector<uint64_t, 64> Record;
599
600  // Read all the records for this type table.
601  std::string TypeName;
602  while (1) {
603    unsigned Code = Stream.ReadCode();
604    if (Code == bitc::END_BLOCK) {
605      if (Stream.ReadBlockEnd())
606        return Error("Error at end of type symbol table block");
607      return false;
608    }
609
610    if (Code == bitc::ENTER_SUBBLOCK) {
611      // No known subblocks, always skip them.
612      Stream.ReadSubBlockID();
613      if (Stream.SkipBlock())
614        return Error("Malformed block record");
615      continue;
616    }
617
618    if (Code == bitc::DEFINE_ABBREV) {
619      Stream.ReadAbbrevRecord();
620      continue;
621    }
622
623    // Read a record.
624    Record.clear();
625    switch (Stream.ReadRecord(Code, Record)) {
626    default:  // Default behavior: unknown type.
627      break;
628    case bitc::TST_CODE_ENTRY:    // TST_ENTRY: [typeid, namechar x N]
629      if (ConvertToString(Record, 1, TypeName))
630        return Error("Invalid TST_ENTRY record");
631      unsigned TypeID = Record[0];
632      if (TypeID >= TypeList.size())
633        return Error("Invalid Type ID in TST_ENTRY record");
634
635      TheModule->addTypeName(TypeName, TypeList[TypeID].get());
636      TypeName.clear();
637      break;
638    }
639  }
640}
641
642bool BitcodeReader::ParseValueSymbolTable() {
643  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
644    return Error("Malformed block record");
645
646  SmallVector<uint64_t, 64> Record;
647
648  // Read all the records for this value table.
649  SmallString<128> ValueName;
650  while (1) {
651    unsigned Code = Stream.ReadCode();
652    if (Code == bitc::END_BLOCK) {
653      if (Stream.ReadBlockEnd())
654        return Error("Error at end of value symbol table block");
655      return false;
656    }
657    if (Code == bitc::ENTER_SUBBLOCK) {
658      // No known subblocks, always skip them.
659      Stream.ReadSubBlockID();
660      if (Stream.SkipBlock())
661        return Error("Malformed block record");
662      continue;
663    }
664
665    if (Code == bitc::DEFINE_ABBREV) {
666      Stream.ReadAbbrevRecord();
667      continue;
668    }
669
670    // Read a record.
671    Record.clear();
672    switch (Stream.ReadRecord(Code, Record)) {
673    default:  // Default behavior: unknown type.
674      break;
675    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
676      if (ConvertToString(Record, 1, ValueName))
677        return Error("Invalid VST_ENTRY record");
678      unsigned ValueID = Record[0];
679      if (ValueID >= ValueList.size())
680        return Error("Invalid Value ID in VST_ENTRY record");
681      Value *V = ValueList[ValueID];
682
683      V->setName(StringRef(ValueName.data(), ValueName.size()));
684      ValueName.clear();
685      break;
686    }
687    case bitc::VST_CODE_BBENTRY: {
688      if (ConvertToString(Record, 1, ValueName))
689        return Error("Invalid VST_BBENTRY record");
690      BasicBlock *BB = getBasicBlock(Record[0]);
691      if (BB == 0)
692        return Error("Invalid BB ID in VST_BBENTRY record");
693
694      BB->setName(StringRef(ValueName.data(), ValueName.size()));
695      ValueName.clear();
696      break;
697    }
698    }
699  }
700}
701
702bool BitcodeReader::ParseMetadata() {
703  unsigned NextValueNo = ValueList.size();
704
705  if (Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
706    return Error("Malformed block record");
707
708  SmallVector<uint64_t, 64> Record;
709
710  // Read all the records.
711  while (1) {
712    unsigned Code = Stream.ReadCode();
713    if (Code == bitc::END_BLOCK) {
714      if (Stream.ReadBlockEnd())
715        return Error("Error at end of PARAMATTR block");
716      return false;
717    }
718
719    if (Code == bitc::ENTER_SUBBLOCK) {
720      // No known subblocks, always skip them.
721      Stream.ReadSubBlockID();
722      if (Stream.SkipBlock())
723        return Error("Malformed block record");
724      continue;
725    }
726
727    if (Code == bitc::DEFINE_ABBREV) {
728      Stream.ReadAbbrevRecord();
729      continue;
730    }
731
732    // Read a record.
733    Record.clear();
734    switch (Stream.ReadRecord(Code, Record)) {
735    default:  // Default behavior: ignore.
736      break;
737    case bitc::METADATA_NAME: {
738      // Read named of the named metadata.
739      unsigned NameLength = Record.size();
740      SmallString<8> Name;
741      Name.resize(NameLength);
742      for (unsigned i = 0; i != NameLength; ++i)
743        Name[i] = Record[i];
744      Record.clear();
745      Code = Stream.ReadCode();
746
747      // METADATA_NAME is always followed by METADATA_NAMED_NODE.
748      if (Stream.ReadRecord(Code, Record) != bitc::METADATA_NAMED_NODE)
749        assert ( 0 && "Inavlid Named Metadata record");
750
751      // Read named metadata elements.
752      unsigned Size = Record.size();
753      SmallVector<MetadataBase*, 8> Elts;
754      for (unsigned i = 0; i != Size; ++i) {
755        Value *MD = ValueList.getValueFwdRef(Record[i], Type::MetadataTy);
756        if (MetadataBase *B = dyn_cast<MetadataBase>(MD))
757        Elts.push_back(B);
758      }
759      Value *V = NamedMDNode::Create(Name.c_str(), Elts.data(), Elts.size(),
760                                     TheModule);
761      ValueList.AssignValue(V, NextValueNo++);
762      break;
763    }
764    case bitc::METADATA_NODE: {
765      if (Record.empty() || Record.size() % 2 == 1)
766        return Error("Invalid METADATA_NODE record");
767
768      unsigned Size = Record.size();
769      SmallVector<Value*, 8> Elts;
770      for (unsigned i = 0; i != Size; i += 2) {
771        const Type *Ty = getTypeByID(Record[i], false);
772        if (Ty != Type::VoidTy)
773          Elts.push_back(ValueList.getValueFwdRef(Record[i+1], Ty));
774        else
775          Elts.push_back(NULL);
776      }
777      Value *V = MDNode::get(Context, &Elts[0], Elts.size());
778      ValueList.AssignValue(V, NextValueNo++);
779      break;
780    }
781    case bitc::METADATA_STRING: {
782      unsigned MDStringLength = Record.size();
783      SmallString<8> String;
784      String.resize(MDStringLength);
785      for (unsigned i = 0; i != MDStringLength; ++i)
786        String[i] = Record[i];
787      Value *V = MDString::get(Context,
788                               StringRef(String.data(), String.size()));
789      ValueList.AssignValue(V, NextValueNo++);
790      break;
791    }
792    }
793  }
794}
795
796/// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
797/// the LSB for dense VBR encoding.
798static uint64_t DecodeSignRotatedValue(uint64_t V) {
799  if ((V & 1) == 0)
800    return V >> 1;
801  if (V != 1)
802    return -(V >> 1);
803  // There is no such thing as -0 with integers.  "-0" really means MININT.
804  return 1ULL << 63;
805}
806
807/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
808/// values and aliases that we can.
809bool BitcodeReader::ResolveGlobalAndAliasInits() {
810  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
811  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
812
813  GlobalInitWorklist.swap(GlobalInits);
814  AliasInitWorklist.swap(AliasInits);
815
816  while (!GlobalInitWorklist.empty()) {
817    unsigned ValID = GlobalInitWorklist.back().second;
818    if (ValID >= ValueList.size()) {
819      // Not ready to resolve this yet, it requires something later in the file.
820      GlobalInits.push_back(GlobalInitWorklist.back());
821    } else {
822      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
823        GlobalInitWorklist.back().first->setInitializer(C);
824      else
825        return Error("Global variable initializer is not a constant!");
826    }
827    GlobalInitWorklist.pop_back();
828  }
829
830  while (!AliasInitWorklist.empty()) {
831    unsigned ValID = AliasInitWorklist.back().second;
832    if (ValID >= ValueList.size()) {
833      AliasInits.push_back(AliasInitWorklist.back());
834    } else {
835      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
836        AliasInitWorklist.back().first->setAliasee(C);
837      else
838        return Error("Alias initializer is not a constant!");
839    }
840    AliasInitWorklist.pop_back();
841  }
842  return false;
843}
844
845static void SetOptimizationFlags(Value *V, uint64_t Flags) {
846  if (OverflowingBinaryOperator *OBO =
847        dyn_cast<OverflowingBinaryOperator>(V)) {
848    if (Flags & (1 << bitc::OBO_NO_SIGNED_OVERFLOW))
849      OBO->setHasNoSignedOverflow(true);
850    if (Flags & (1 << bitc::OBO_NO_UNSIGNED_OVERFLOW))
851      OBO->setHasNoUnsignedOverflow(true);
852  } else if (SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
853    if (Flags & (1 << bitc::SDIV_EXACT))
854      Div->setIsExact(true);
855  }
856}
857
858bool BitcodeReader::ParseConstants() {
859  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
860    return Error("Malformed block record");
861
862  SmallVector<uint64_t, 64> Record;
863
864  // Read all the records for this value table.
865  const Type *CurTy = Type::Int32Ty;
866  unsigned NextCstNo = ValueList.size();
867  while (1) {
868    unsigned Code = Stream.ReadCode();
869    if (Code == bitc::END_BLOCK)
870      break;
871
872    if (Code == bitc::ENTER_SUBBLOCK) {
873      // No known subblocks, always skip them.
874      Stream.ReadSubBlockID();
875      if (Stream.SkipBlock())
876        return Error("Malformed block record");
877      continue;
878    }
879
880    if (Code == bitc::DEFINE_ABBREV) {
881      Stream.ReadAbbrevRecord();
882      continue;
883    }
884
885    // Read a record.
886    Record.clear();
887    Value *V = 0;
888    unsigned BitCode = Stream.ReadRecord(Code, Record);
889    switch (BitCode) {
890    default:  // Default behavior: unknown constant
891    case bitc::CST_CODE_UNDEF:     // UNDEF
892      V = UndefValue::get(CurTy);
893      break;
894    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
895      if (Record.empty())
896        return Error("Malformed CST_SETTYPE record");
897      if (Record[0] >= TypeList.size())
898        return Error("Invalid Type ID in CST_SETTYPE record");
899      CurTy = TypeList[Record[0]];
900      continue;  // Skip the ValueList manipulation.
901    case bitc::CST_CODE_NULL:      // NULL
902      V = Constant::getNullValue(CurTy);
903      break;
904    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
905      if (!isa<IntegerType>(CurTy) || Record.empty())
906        return Error("Invalid CST_INTEGER record");
907      V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
908      break;
909    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
910      if (!isa<IntegerType>(CurTy) || Record.empty())
911        return Error("Invalid WIDE_INTEGER record");
912
913      unsigned NumWords = Record.size();
914      SmallVector<uint64_t, 8> Words;
915      Words.resize(NumWords);
916      for (unsigned i = 0; i != NumWords; ++i)
917        Words[i] = DecodeSignRotatedValue(Record[i]);
918      V = ConstantInt::get(Context,
919                           APInt(cast<IntegerType>(CurTy)->getBitWidth(),
920                           NumWords, &Words[0]));
921      break;
922    }
923    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
924      if (Record.empty())
925        return Error("Invalid FLOAT record");
926      if (CurTy == Type::FloatTy)
927        V = ConstantFP::get(Context, APFloat(APInt(32, (uint32_t)Record[0])));
928      else if (CurTy == Type::DoubleTy)
929        V = ConstantFP::get(Context, APFloat(APInt(64, Record[0])));
930      else if (CurTy == Type::X86_FP80Ty) {
931        // Bits are not stored the same way as a normal i80 APInt, compensate.
932        uint64_t Rearrange[2];
933        Rearrange[0] = (Record[1] & 0xffffLL) | (Record[0] << 16);
934        Rearrange[1] = Record[0] >> 48;
935        V = ConstantFP::get(Context, APFloat(APInt(80, 2, Rearrange)));
936      } else if (CurTy == Type::FP128Ty)
937        V = ConstantFP::get(Context, APFloat(APInt(128, 2, &Record[0]), true));
938      else if (CurTy == Type::PPC_FP128Ty)
939        V = ConstantFP::get(Context, APFloat(APInt(128, 2, &Record[0])));
940      else
941        V = UndefValue::get(CurTy);
942      break;
943    }
944
945    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
946      if (Record.empty())
947        return Error("Invalid CST_AGGREGATE record");
948
949      unsigned Size = Record.size();
950      std::vector<Constant*> Elts;
951
952      if (const StructType *STy = dyn_cast<StructType>(CurTy)) {
953        for (unsigned i = 0; i != Size; ++i)
954          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
955                                                     STy->getElementType(i)));
956        V = ConstantStruct::get(STy, Elts);
957      } else if (const ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
958        const Type *EltTy = ATy->getElementType();
959        for (unsigned i = 0; i != Size; ++i)
960          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
961        V = ConstantArray::get(ATy, Elts);
962      } else if (const VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
963        const Type *EltTy = VTy->getElementType();
964        for (unsigned i = 0; i != Size; ++i)
965          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
966        V = ConstantVector::get(Elts);
967      } else {
968        V = UndefValue::get(CurTy);
969      }
970      break;
971    }
972    case bitc::CST_CODE_STRING: { // STRING: [values]
973      if (Record.empty())
974        return Error("Invalid CST_AGGREGATE record");
975
976      const ArrayType *ATy = cast<ArrayType>(CurTy);
977      const Type *EltTy = ATy->getElementType();
978
979      unsigned Size = Record.size();
980      std::vector<Constant*> Elts;
981      for (unsigned i = 0; i != Size; ++i)
982        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
983      V = ConstantArray::get(ATy, Elts);
984      break;
985    }
986    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
987      if (Record.empty())
988        return Error("Invalid CST_AGGREGATE record");
989
990      const ArrayType *ATy = cast<ArrayType>(CurTy);
991      const Type *EltTy = ATy->getElementType();
992
993      unsigned Size = Record.size();
994      std::vector<Constant*> Elts;
995      for (unsigned i = 0; i != Size; ++i)
996        Elts.push_back(ConstantInt::get(EltTy, Record[i]));
997      Elts.push_back(Constant::getNullValue(EltTy));
998      V = ConstantArray::get(ATy, Elts);
999      break;
1000    }
1001    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
1002      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
1003      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
1004      if (Opc < 0) {
1005        V = UndefValue::get(CurTy);  // Unknown binop.
1006      } else {
1007        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
1008        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
1009        V = ConstantExpr::get(Opc, LHS, RHS);
1010      }
1011      if (Record.size() >= 4)
1012        SetOptimizationFlags(V, Record[3]);
1013      break;
1014    }
1015    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
1016      if (Record.size() < 3) return Error("Invalid CE_CAST record");
1017      int Opc = GetDecodedCastOpcode(Record[0]);
1018      if (Opc < 0) {
1019        V = UndefValue::get(CurTy);  // Unknown cast.
1020      } else {
1021        const Type *OpTy = getTypeByID(Record[1]);
1022        if (!OpTy) return Error("Invalid CE_CAST record");
1023        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
1024        V = ConstantExpr::getCast(Opc, Op, CurTy);
1025      }
1026      break;
1027    }
1028    case bitc::CST_CODE_CE_INBOUNDS_GEP:
1029    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
1030      if (Record.size() & 1) return Error("Invalid CE_GEP record");
1031      SmallVector<Constant*, 16> Elts;
1032      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
1033        const Type *ElTy = getTypeByID(Record[i]);
1034        if (!ElTy) return Error("Invalid CE_GEP record");
1035        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
1036      }
1037      V = ConstantExpr::getGetElementPtr(Elts[0], &Elts[1],
1038                                               Elts.size()-1);
1039      if (BitCode == bitc::CST_CODE_CE_INBOUNDS_GEP)
1040        cast<GEPOperator>(V)->setIsInBounds(true);
1041      break;
1042    }
1043    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
1044      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
1045      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
1046                                                              Type::Int1Ty),
1047                                  ValueList.getConstantFwdRef(Record[1],CurTy),
1048                                  ValueList.getConstantFwdRef(Record[2],CurTy));
1049      break;
1050    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
1051      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
1052      const VectorType *OpTy =
1053        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1054      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
1055      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1056      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
1057      V = ConstantExpr::getExtractElement(Op0, Op1);
1058      break;
1059    }
1060    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
1061      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1062      if (Record.size() < 3 || OpTy == 0)
1063        return Error("Invalid CE_INSERTELT record");
1064      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1065      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
1066                                                  OpTy->getElementType());
1067      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::Int32Ty);
1068      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
1069      break;
1070    }
1071    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
1072      const VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1073      if (Record.size() < 3 || OpTy == 0)
1074        return Error("Invalid CE_SHUFFLEVEC record");
1075      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1076      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
1077      const Type *ShufTy = VectorType::get(Type::Int32Ty,
1078                                                 OpTy->getNumElements());
1079      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
1080      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1081      break;
1082    }
1083    case bitc::CST_CODE_CE_SHUFVEC_EX: { // [opty, opval, opval, opval]
1084      const VectorType *RTy = dyn_cast<VectorType>(CurTy);
1085      const VectorType *OpTy = dyn_cast<VectorType>(getTypeByID(Record[0]));
1086      if (Record.size() < 4 || RTy == 0 || OpTy == 0)
1087        return Error("Invalid CE_SHUFVEC_EX record");
1088      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1089      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1090      const Type *ShufTy = VectorType::get(Type::Int32Ty,
1091                                                 RTy->getNumElements());
1092      Constant *Op2 = ValueList.getConstantFwdRef(Record[3], ShufTy);
1093      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1094      break;
1095    }
1096    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
1097      if (Record.size() < 4) return Error("Invalid CE_CMP record");
1098      const Type *OpTy = getTypeByID(Record[0]);
1099      if (OpTy == 0) return Error("Invalid CE_CMP record");
1100      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1101      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1102
1103      if (OpTy->isFloatingPoint())
1104        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
1105      else
1106        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
1107      break;
1108    }
1109    case bitc::CST_CODE_INLINEASM: {
1110      if (Record.size() < 2) return Error("Invalid INLINEASM record");
1111      std::string AsmStr, ConstrStr;
1112      bool HasSideEffects = Record[0];
1113      unsigned AsmStrSize = Record[1];
1114      if (2+AsmStrSize >= Record.size())
1115        return Error("Invalid INLINEASM record");
1116      unsigned ConstStrSize = Record[2+AsmStrSize];
1117      if (3+AsmStrSize+ConstStrSize > Record.size())
1118        return Error("Invalid INLINEASM record");
1119
1120      for (unsigned i = 0; i != AsmStrSize; ++i)
1121        AsmStr += (char)Record[2+i];
1122      for (unsigned i = 0; i != ConstStrSize; ++i)
1123        ConstrStr += (char)Record[3+AsmStrSize+i];
1124      const PointerType *PTy = cast<PointerType>(CurTy);
1125      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
1126                         AsmStr, ConstrStr, HasSideEffects);
1127      break;
1128    }
1129    }
1130
1131    ValueList.AssignValue(V, NextCstNo);
1132    ++NextCstNo;
1133  }
1134
1135  if (NextCstNo != ValueList.size())
1136    return Error("Invalid constant reference!");
1137
1138  if (Stream.ReadBlockEnd())
1139    return Error("Error at end of constants block");
1140
1141  // Once all the constants have been read, go through and resolve forward
1142  // references.
1143  ValueList.ResolveConstantForwardRefs();
1144  return false;
1145}
1146
1147/// RememberAndSkipFunctionBody - When we see the block for a function body,
1148/// remember where it is and then skip it.  This lets us lazily deserialize the
1149/// functions.
1150bool BitcodeReader::RememberAndSkipFunctionBody() {
1151  // Get the function we are talking about.
1152  if (FunctionsWithBodies.empty())
1153    return Error("Insufficient function protos");
1154
1155  Function *Fn = FunctionsWithBodies.back();
1156  FunctionsWithBodies.pop_back();
1157
1158  // Save the current stream state.
1159  uint64_t CurBit = Stream.GetCurrentBitNo();
1160  DeferredFunctionInfo[Fn] = std::make_pair(CurBit, Fn->getLinkage());
1161
1162  // Set the functions linkage to GhostLinkage so we know it is lazily
1163  // deserialized.
1164  Fn->setLinkage(GlobalValue::GhostLinkage);
1165
1166  // Skip over the function block for now.
1167  if (Stream.SkipBlock())
1168    return Error("Malformed block record");
1169  return false;
1170}
1171
1172bool BitcodeReader::ParseModule(const std::string &ModuleID) {
1173  // Reject multiple MODULE_BLOCK's in a single bitstream.
1174  if (TheModule)
1175    return Error("Multiple MODULE_BLOCKs in same stream");
1176
1177  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
1178    return Error("Malformed block record");
1179
1180  // Otherwise, create the module.
1181  TheModule = new Module(ModuleID, Context);
1182
1183  SmallVector<uint64_t, 64> Record;
1184  std::vector<std::string> SectionTable;
1185  std::vector<std::string> GCTable;
1186
1187  // Read all the records for this module.
1188  while (!Stream.AtEndOfStream()) {
1189    unsigned Code = Stream.ReadCode();
1190    if (Code == bitc::END_BLOCK) {
1191      if (Stream.ReadBlockEnd())
1192        return Error("Error at end of module block");
1193
1194      // Patch the initializers for globals and aliases up.
1195      ResolveGlobalAndAliasInits();
1196      if (!GlobalInits.empty() || !AliasInits.empty())
1197        return Error("Malformed global initializer set");
1198      if (!FunctionsWithBodies.empty())
1199        return Error("Too few function bodies found");
1200
1201      // Look for intrinsic functions which need to be upgraded at some point
1202      for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
1203           FI != FE; ++FI) {
1204        Function* NewFn;
1205        if (UpgradeIntrinsicFunction(FI, NewFn))
1206          UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
1207      }
1208
1209      // Force deallocation of memory for these vectors to favor the client that
1210      // want lazy deserialization.
1211      std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
1212      std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
1213      std::vector<Function*>().swap(FunctionsWithBodies);
1214      return false;
1215    }
1216
1217    if (Code == bitc::ENTER_SUBBLOCK) {
1218      switch (Stream.ReadSubBlockID()) {
1219      default:  // Skip unknown content.
1220        if (Stream.SkipBlock())
1221          return Error("Malformed block record");
1222        break;
1223      case bitc::BLOCKINFO_BLOCK_ID:
1224        if (Stream.ReadBlockInfoBlock())
1225          return Error("Malformed BlockInfoBlock");
1226        break;
1227      case bitc::PARAMATTR_BLOCK_ID:
1228        if (ParseAttributeBlock())
1229          return true;
1230        break;
1231      case bitc::TYPE_BLOCK_ID:
1232        if (ParseTypeTable())
1233          return true;
1234        break;
1235      case bitc::TYPE_SYMTAB_BLOCK_ID:
1236        if (ParseTypeSymbolTable())
1237          return true;
1238        break;
1239      case bitc::VALUE_SYMTAB_BLOCK_ID:
1240        if (ParseValueSymbolTable())
1241          return true;
1242        break;
1243      case bitc::CONSTANTS_BLOCK_ID:
1244        if (ParseConstants() || ResolveGlobalAndAliasInits())
1245          return true;
1246        break;
1247      case bitc::METADATA_BLOCK_ID:
1248        if (ParseMetadata())
1249          return true;
1250        break;
1251      case bitc::FUNCTION_BLOCK_ID:
1252        // If this is the first function body we've seen, reverse the
1253        // FunctionsWithBodies list.
1254        if (!HasReversedFunctionsWithBodies) {
1255          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
1256          HasReversedFunctionsWithBodies = true;
1257        }
1258
1259        if (RememberAndSkipFunctionBody())
1260          return true;
1261        break;
1262      }
1263      continue;
1264    }
1265
1266    if (Code == bitc::DEFINE_ABBREV) {
1267      Stream.ReadAbbrevRecord();
1268      continue;
1269    }
1270
1271    // Read a record.
1272    switch (Stream.ReadRecord(Code, Record)) {
1273    default: break;  // Default behavior, ignore unknown content.
1274    case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
1275      if (Record.size() < 1)
1276        return Error("Malformed MODULE_CODE_VERSION");
1277      // Only version #0 is supported so far.
1278      if (Record[0] != 0)
1279        return Error("Unknown bitstream version!");
1280      break;
1281    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1282      std::string S;
1283      if (ConvertToString(Record, 0, S))
1284        return Error("Invalid MODULE_CODE_TRIPLE record");
1285      TheModule->setTargetTriple(S);
1286      break;
1287    }
1288    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
1289      std::string S;
1290      if (ConvertToString(Record, 0, S))
1291        return Error("Invalid MODULE_CODE_DATALAYOUT record");
1292      TheModule->setDataLayout(S);
1293      break;
1294    }
1295    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
1296      std::string S;
1297      if (ConvertToString(Record, 0, S))
1298        return Error("Invalid MODULE_CODE_ASM record");
1299      TheModule->setModuleInlineAsm(S);
1300      break;
1301    }
1302    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
1303      std::string S;
1304      if (ConvertToString(Record, 0, S))
1305        return Error("Invalid MODULE_CODE_DEPLIB record");
1306      TheModule->addLibrary(S);
1307      break;
1308    }
1309    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
1310      std::string S;
1311      if (ConvertToString(Record, 0, S))
1312        return Error("Invalid MODULE_CODE_SECTIONNAME record");
1313      SectionTable.push_back(S);
1314      break;
1315    }
1316    case bitc::MODULE_CODE_GCNAME: {  // SECTIONNAME: [strchr x N]
1317      std::string S;
1318      if (ConvertToString(Record, 0, S))
1319        return Error("Invalid MODULE_CODE_GCNAME record");
1320      GCTable.push_back(S);
1321      break;
1322    }
1323    // GLOBALVAR: [pointer type, isconst, initid,
1324    //             linkage, alignment, section, visibility, threadlocal]
1325    case bitc::MODULE_CODE_GLOBALVAR: {
1326      if (Record.size() < 6)
1327        return Error("Invalid MODULE_CODE_GLOBALVAR record");
1328      const Type *Ty = getTypeByID(Record[0]);
1329      if (!isa<PointerType>(Ty))
1330        return Error("Global not a pointer type!");
1331      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
1332      Ty = cast<PointerType>(Ty)->getElementType();
1333
1334      bool isConstant = Record[1];
1335      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1336      unsigned Alignment = (1 << Record[4]) >> 1;
1337      std::string Section;
1338      if (Record[5]) {
1339        if (Record[5]-1 >= SectionTable.size())
1340          return Error("Invalid section ID");
1341        Section = SectionTable[Record[5]-1];
1342      }
1343      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1344      if (Record.size() > 6)
1345        Visibility = GetDecodedVisibility(Record[6]);
1346      bool isThreadLocal = false;
1347      if (Record.size() > 7)
1348        isThreadLocal = Record[7];
1349
1350      GlobalVariable *NewGV =
1351        new GlobalVariable(*TheModule, Ty, isConstant, Linkage, 0, "", 0,
1352                           isThreadLocal, AddressSpace);
1353      NewGV->setAlignment(Alignment);
1354      if (!Section.empty())
1355        NewGV->setSection(Section);
1356      NewGV->setVisibility(Visibility);
1357      NewGV->setThreadLocal(isThreadLocal);
1358
1359      ValueList.push_back(NewGV);
1360
1361      // Remember which value to use for the global initializer.
1362      if (unsigned InitID = Record[2])
1363        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1364      break;
1365    }
1366    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1367    //             alignment, section, visibility, gc]
1368    case bitc::MODULE_CODE_FUNCTION: {
1369      if (Record.size() < 8)
1370        return Error("Invalid MODULE_CODE_FUNCTION record");
1371      const Type *Ty = getTypeByID(Record[0]);
1372      if (!isa<PointerType>(Ty))
1373        return Error("Function not a pointer type!");
1374      const FunctionType *FTy =
1375        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1376      if (!FTy)
1377        return Error("Function not a pointer to function type!");
1378
1379      Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
1380                                        "", TheModule);
1381
1382      Func->setCallingConv(Record[1]);
1383      bool isProto = Record[2];
1384      Func->setLinkage(GetDecodedLinkage(Record[3]));
1385      Func->setAttributes(getAttributes(Record[4]));
1386
1387      Func->setAlignment((1 << Record[5]) >> 1);
1388      if (Record[6]) {
1389        if (Record[6]-1 >= SectionTable.size())
1390          return Error("Invalid section ID");
1391        Func->setSection(SectionTable[Record[6]-1]);
1392      }
1393      Func->setVisibility(GetDecodedVisibility(Record[7]));
1394      if (Record.size() > 8 && Record[8]) {
1395        if (Record[8]-1 > GCTable.size())
1396          return Error("Invalid GC ID");
1397        Func->setGC(GCTable[Record[8]-1].c_str());
1398      }
1399      ValueList.push_back(Func);
1400
1401      // If this is a function with a body, remember the prototype we are
1402      // creating now, so that we can match up the body with them later.
1403      if (!isProto)
1404        FunctionsWithBodies.push_back(Func);
1405      break;
1406    }
1407    // ALIAS: [alias type, aliasee val#, linkage]
1408    // ALIAS: [alias type, aliasee val#, linkage, visibility]
1409    case bitc::MODULE_CODE_ALIAS: {
1410      if (Record.size() < 3)
1411        return Error("Invalid MODULE_ALIAS record");
1412      const Type *Ty = getTypeByID(Record[0]);
1413      if (!isa<PointerType>(Ty))
1414        return Error("Function not a pointer type!");
1415
1416      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1417                                           "", 0, TheModule);
1418      // Old bitcode files didn't have visibility field.
1419      if (Record.size() > 3)
1420        NewGA->setVisibility(GetDecodedVisibility(Record[3]));
1421      ValueList.push_back(NewGA);
1422      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1423      break;
1424    }
1425    /// MODULE_CODE_PURGEVALS: [numvals]
1426    case bitc::MODULE_CODE_PURGEVALS:
1427      // Trim down the value list to the specified size.
1428      if (Record.size() < 1 || Record[0] > ValueList.size())
1429        return Error("Invalid MODULE_PURGEVALS record");
1430      ValueList.shrinkTo(Record[0]);
1431      break;
1432    }
1433    Record.clear();
1434  }
1435
1436  return Error("Premature end of bitstream");
1437}
1438
1439bool BitcodeReader::ParseBitcode() {
1440  TheModule = 0;
1441
1442  if (Buffer->getBufferSize() & 3)
1443    return Error("Bitcode stream should be a multiple of 4 bytes in length");
1444
1445  unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1446  unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
1447
1448  // If we have a wrapper header, parse it and ignore the non-bc file contents.
1449  // The magic number is 0x0B17C0DE stored in little endian.
1450  if (isBitcodeWrapper(BufPtr, BufEnd))
1451    if (SkipBitcodeWrapperHeader(BufPtr, BufEnd))
1452      return Error("Invalid bitcode wrapper header");
1453
1454  StreamFile.init(BufPtr, BufEnd);
1455  Stream.init(StreamFile);
1456
1457  // Sniff for the signature.
1458  if (Stream.Read(8) != 'B' ||
1459      Stream.Read(8) != 'C' ||
1460      Stream.Read(4) != 0x0 ||
1461      Stream.Read(4) != 0xC ||
1462      Stream.Read(4) != 0xE ||
1463      Stream.Read(4) != 0xD)
1464    return Error("Invalid bitcode signature");
1465
1466  // We expect a number of well-defined blocks, though we don't necessarily
1467  // need to understand them all.
1468  while (!Stream.AtEndOfStream()) {
1469    unsigned Code = Stream.ReadCode();
1470
1471    if (Code != bitc::ENTER_SUBBLOCK)
1472      return Error("Invalid record at top-level");
1473
1474    unsigned BlockID = Stream.ReadSubBlockID();
1475
1476    // We only know the MODULE subblock ID.
1477    switch (BlockID) {
1478    case bitc::BLOCKINFO_BLOCK_ID:
1479      if (Stream.ReadBlockInfoBlock())
1480        return Error("Malformed BlockInfoBlock");
1481      break;
1482    case bitc::MODULE_BLOCK_ID:
1483      if (ParseModule(Buffer->getBufferIdentifier()))
1484        return true;
1485      break;
1486    default:
1487      if (Stream.SkipBlock())
1488        return Error("Malformed block record");
1489      break;
1490    }
1491  }
1492
1493  return false;
1494}
1495
1496
1497/// ParseFunctionBody - Lazily parse the specified function body block.
1498bool BitcodeReader::ParseFunctionBody(Function *F) {
1499  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1500    return Error("Malformed block record");
1501
1502  unsigned ModuleValueListSize = ValueList.size();
1503
1504  // Add all the function arguments to the value table.
1505  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1506    ValueList.push_back(I);
1507
1508  unsigned NextValueNo = ValueList.size();
1509  BasicBlock *CurBB = 0;
1510  unsigned CurBBNo = 0;
1511
1512  // Read all the records.
1513  SmallVector<uint64_t, 64> Record;
1514  while (1) {
1515    unsigned Code = Stream.ReadCode();
1516    if (Code == bitc::END_BLOCK) {
1517      if (Stream.ReadBlockEnd())
1518        return Error("Error at end of function block");
1519      break;
1520    }
1521
1522    if (Code == bitc::ENTER_SUBBLOCK) {
1523      switch (Stream.ReadSubBlockID()) {
1524      default:  // Skip unknown content.
1525        if (Stream.SkipBlock())
1526          return Error("Malformed block record");
1527        break;
1528      case bitc::CONSTANTS_BLOCK_ID:
1529        if (ParseConstants()) return true;
1530        NextValueNo = ValueList.size();
1531        break;
1532      case bitc::VALUE_SYMTAB_BLOCK_ID:
1533        if (ParseValueSymbolTable()) return true;
1534        break;
1535      }
1536      continue;
1537    }
1538
1539    if (Code == bitc::DEFINE_ABBREV) {
1540      Stream.ReadAbbrevRecord();
1541      continue;
1542    }
1543
1544    // Read a record.
1545    Record.clear();
1546    Instruction *I = 0;
1547    unsigned BitCode = Stream.ReadRecord(Code, Record);
1548    switch (BitCode) {
1549    default: // Default behavior: reject
1550      return Error("Unknown instruction");
1551    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1552      if (Record.size() < 1 || Record[0] == 0)
1553        return Error("Invalid DECLAREBLOCKS record");
1554      // Create all the basic blocks for the function.
1555      FunctionBBs.resize(Record[0]);
1556      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1557        FunctionBBs[i] = BasicBlock::Create("", F);
1558      CurBB = FunctionBBs[0];
1559      continue;
1560
1561    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1562      unsigned OpNum = 0;
1563      Value *LHS, *RHS;
1564      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1565          getValue(Record, OpNum, LHS->getType(), RHS) ||
1566          OpNum+1 > Record.size())
1567        return Error("Invalid BINOP record");
1568
1569      int Opc = GetDecodedBinaryOpcode(Record[OpNum++], LHS->getType());
1570      if (Opc == -1) return Error("Invalid BINOP record");
1571      I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
1572      if (OpNum < Record.size())
1573        SetOptimizationFlags(I, Record[3]);
1574      break;
1575    }
1576    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
1577      unsigned OpNum = 0;
1578      Value *Op;
1579      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1580          OpNum+2 != Record.size())
1581        return Error("Invalid CAST record");
1582
1583      const Type *ResTy = getTypeByID(Record[OpNum]);
1584      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
1585      if (Opc == -1 || ResTy == 0)
1586        return Error("Invalid CAST record");
1587      I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
1588      break;
1589    }
1590    case bitc::FUNC_CODE_INST_INBOUNDS_GEP:
1591    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
1592      unsigned OpNum = 0;
1593      Value *BasePtr;
1594      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
1595        return Error("Invalid GEP record");
1596
1597      SmallVector<Value*, 16> GEPIdx;
1598      while (OpNum != Record.size()) {
1599        Value *Op;
1600        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1601          return Error("Invalid GEP record");
1602        GEPIdx.push_back(Op);
1603      }
1604
1605      I = GetElementPtrInst::Create(BasePtr, GEPIdx.begin(), GEPIdx.end());
1606      if (BitCode == bitc::FUNC_CODE_INST_INBOUNDS_GEP)
1607        cast<GEPOperator>(I)->setIsInBounds(true);
1608      break;
1609    }
1610
1611    case bitc::FUNC_CODE_INST_EXTRACTVAL: {
1612                                       // EXTRACTVAL: [opty, opval, n x indices]
1613      unsigned OpNum = 0;
1614      Value *Agg;
1615      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
1616        return Error("Invalid EXTRACTVAL record");
1617
1618      SmallVector<unsigned, 4> EXTRACTVALIdx;
1619      for (unsigned RecSize = Record.size();
1620           OpNum != RecSize; ++OpNum) {
1621        uint64_t Index = Record[OpNum];
1622        if ((unsigned)Index != Index)
1623          return Error("Invalid EXTRACTVAL index");
1624        EXTRACTVALIdx.push_back((unsigned)Index);
1625      }
1626
1627      I = ExtractValueInst::Create(Agg,
1628                                   EXTRACTVALIdx.begin(), EXTRACTVALIdx.end());
1629      break;
1630    }
1631
1632    case bitc::FUNC_CODE_INST_INSERTVAL: {
1633                           // INSERTVAL: [opty, opval, opty, opval, n x indices]
1634      unsigned OpNum = 0;
1635      Value *Agg;
1636      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
1637        return Error("Invalid INSERTVAL record");
1638      Value *Val;
1639      if (getValueTypePair(Record, OpNum, NextValueNo, Val))
1640        return Error("Invalid INSERTVAL record");
1641
1642      SmallVector<unsigned, 4> INSERTVALIdx;
1643      for (unsigned RecSize = Record.size();
1644           OpNum != RecSize; ++OpNum) {
1645        uint64_t Index = Record[OpNum];
1646        if ((unsigned)Index != Index)
1647          return Error("Invalid INSERTVAL index");
1648        INSERTVALIdx.push_back((unsigned)Index);
1649      }
1650
1651      I = InsertValueInst::Create(Agg, Val,
1652                                  INSERTVALIdx.begin(), INSERTVALIdx.end());
1653      break;
1654    }
1655
1656    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
1657      // obsolete form of select
1658      // handles select i1 ... in old bitcode
1659      unsigned OpNum = 0;
1660      Value *TrueVal, *FalseVal, *Cond;
1661      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
1662          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
1663          getValue(Record, OpNum, Type::Int1Ty, Cond))
1664        return Error("Invalid SELECT record");
1665
1666      I = SelectInst::Create(Cond, TrueVal, FalseVal);
1667      break;
1668    }
1669
1670    case bitc::FUNC_CODE_INST_VSELECT: {// VSELECT: [ty,opval,opval,predty,pred]
1671      // new form of select
1672      // handles select i1 or select [N x i1]
1673      unsigned OpNum = 0;
1674      Value *TrueVal, *FalseVal, *Cond;
1675      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
1676          getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
1677          getValueTypePair(Record, OpNum, NextValueNo, Cond))
1678        return Error("Invalid SELECT record");
1679
1680      // select condition can be either i1 or [N x i1]
1681      if (const VectorType* vector_type =
1682          dyn_cast<const VectorType>(Cond->getType())) {
1683        // expect <n x i1>
1684        if (vector_type->getElementType() != Type::Int1Ty)
1685          return Error("Invalid SELECT condition type");
1686      } else {
1687        // expect i1
1688        if (Cond->getType() != Type::Int1Ty)
1689          return Error("Invalid SELECT condition type");
1690      }
1691
1692      I = SelectInst::Create(Cond, TrueVal, FalseVal);
1693      break;
1694    }
1695
1696    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
1697      unsigned OpNum = 0;
1698      Value *Vec, *Idx;
1699      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1700          getValue(Record, OpNum, Type::Int32Ty, Idx))
1701        return Error("Invalid EXTRACTELT record");
1702      I = ExtractElementInst::Create(Vec, Idx);
1703      break;
1704    }
1705
1706    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
1707      unsigned OpNum = 0;
1708      Value *Vec, *Elt, *Idx;
1709      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
1710          getValue(Record, OpNum,
1711                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
1712          getValue(Record, OpNum, Type::Int32Ty, Idx))
1713        return Error("Invalid INSERTELT record");
1714      I = InsertElementInst::Create(Vec, Elt, Idx);
1715      break;
1716    }
1717
1718    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
1719      unsigned OpNum = 0;
1720      Value *Vec1, *Vec2, *Mask;
1721      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
1722          getValue(Record, OpNum, Vec1->getType(), Vec2))
1723        return Error("Invalid SHUFFLEVEC record");
1724
1725      if (getValueTypePair(Record, OpNum, NextValueNo, Mask))
1726        return Error("Invalid SHUFFLEVEC record");
1727      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
1728      break;
1729    }
1730
1731    case bitc::FUNC_CODE_INST_CMP:   // CMP: [opty, opval, opval, pred]
1732      // Old form of ICmp/FCmp returning bool
1733      // Existed to differentiate between icmp/fcmp and vicmp/vfcmp which were
1734      // both legal on vectors but had different behaviour.
1735    case bitc::FUNC_CODE_INST_CMP2: { // CMP2: [opty, opval, opval, pred]
1736      // FCmp/ICmp returning bool or vector of bool
1737
1738      unsigned OpNum = 0;
1739      Value *LHS, *RHS;
1740      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1741          getValue(Record, OpNum, LHS->getType(), RHS) ||
1742          OpNum+1 != Record.size())
1743        return Error("Invalid CMP record");
1744
1745      if (LHS->getType()->isFPOrFPVector())
1746        I = new FCmpInst(Context, (FCmpInst::Predicate)Record[OpNum], LHS, RHS);
1747      else
1748        I = new ICmpInst(Context, (ICmpInst::Predicate)Record[OpNum], LHS, RHS);
1749      break;
1750    }
1751
1752    case bitc::FUNC_CODE_INST_GETRESULT: { // GETRESULT: [ty, val, n]
1753      if (Record.size() != 2)
1754        return Error("Invalid GETRESULT record");
1755      unsigned OpNum = 0;
1756      Value *Op;
1757      getValueTypePair(Record, OpNum, NextValueNo, Op);
1758      unsigned Index = Record[1];
1759      I = ExtractValueInst::Create(Op, Index);
1760      break;
1761    }
1762
1763    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
1764      {
1765        unsigned Size = Record.size();
1766        if (Size == 0) {
1767          I = ReturnInst::Create();
1768          break;
1769        }
1770
1771        unsigned OpNum = 0;
1772        SmallVector<Value *,4> Vs;
1773        do {
1774          Value *Op = NULL;
1775          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1776            return Error("Invalid RET record");
1777          Vs.push_back(Op);
1778        } while(OpNum != Record.size());
1779
1780        const Type *ReturnType = F->getReturnType();
1781        if (Vs.size() > 1 ||
1782            (isa<StructType>(ReturnType) &&
1783             (Vs.empty() || Vs[0]->getType() != ReturnType))) {
1784          Value *RV = UndefValue::get(ReturnType);
1785          for (unsigned i = 0, e = Vs.size(); i != e; ++i) {
1786            I = InsertValueInst::Create(RV, Vs[i], i, "mrv");
1787            CurBB->getInstList().push_back(I);
1788            ValueList.AssignValue(I, NextValueNo++);
1789            RV = I;
1790          }
1791          I = ReturnInst::Create(RV);
1792          break;
1793        }
1794
1795        I = ReturnInst::Create(Vs[0]);
1796        break;
1797      }
1798    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
1799      if (Record.size() != 1 && Record.size() != 3)
1800        return Error("Invalid BR record");
1801      BasicBlock *TrueDest = getBasicBlock(Record[0]);
1802      if (TrueDest == 0)
1803        return Error("Invalid BR record");
1804
1805      if (Record.size() == 1)
1806        I = BranchInst::Create(TrueDest);
1807      else {
1808        BasicBlock *FalseDest = getBasicBlock(Record[1]);
1809        Value *Cond = getFnValueByID(Record[2], Type::Int1Ty);
1810        if (FalseDest == 0 || Cond == 0)
1811          return Error("Invalid BR record");
1812        I = BranchInst::Create(TrueDest, FalseDest, Cond);
1813      }
1814      break;
1815    }
1816    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, opval, n, n x ops]
1817      if (Record.size() < 3 || (Record.size() & 1) == 0)
1818        return Error("Invalid SWITCH record");
1819      const Type *OpTy = getTypeByID(Record[0]);
1820      Value *Cond = getFnValueByID(Record[1], OpTy);
1821      BasicBlock *Default = getBasicBlock(Record[2]);
1822      if (OpTy == 0 || Cond == 0 || Default == 0)
1823        return Error("Invalid SWITCH record");
1824      unsigned NumCases = (Record.size()-3)/2;
1825      SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
1826      for (unsigned i = 0, e = NumCases; i != e; ++i) {
1827        ConstantInt *CaseVal =
1828          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
1829        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
1830        if (CaseVal == 0 || DestBB == 0) {
1831          delete SI;
1832          return Error("Invalid SWITCH record!");
1833        }
1834        SI->addCase(CaseVal, DestBB);
1835      }
1836      I = SI;
1837      break;
1838    }
1839
1840    case bitc::FUNC_CODE_INST_INVOKE: {
1841      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
1842      if (Record.size() < 4) return Error("Invalid INVOKE record");
1843      AttrListPtr PAL = getAttributes(Record[0]);
1844      unsigned CCInfo = Record[1];
1845      BasicBlock *NormalBB = getBasicBlock(Record[2]);
1846      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
1847
1848      unsigned OpNum = 4;
1849      Value *Callee;
1850      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1851        return Error("Invalid INVOKE record");
1852
1853      const PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
1854      const FunctionType *FTy = !CalleeTy ? 0 :
1855        dyn_cast<FunctionType>(CalleeTy->getElementType());
1856
1857      // Check that the right number of fixed parameters are here.
1858      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
1859          Record.size() < OpNum+FTy->getNumParams())
1860        return Error("Invalid INVOKE record");
1861
1862      SmallVector<Value*, 16> Ops;
1863      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
1864        Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
1865        if (Ops.back() == 0) return Error("Invalid INVOKE record");
1866      }
1867
1868      if (!FTy->isVarArg()) {
1869        if (Record.size() != OpNum)
1870          return Error("Invalid INVOKE record");
1871      } else {
1872        // Read type/value pairs for varargs params.
1873        while (OpNum != Record.size()) {
1874          Value *Op;
1875          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
1876            return Error("Invalid INVOKE record");
1877          Ops.push_back(Op);
1878        }
1879      }
1880
1881      I = InvokeInst::Create(Callee, NormalBB, UnwindBB,
1882                             Ops.begin(), Ops.end());
1883      cast<InvokeInst>(I)->setCallingConv(CCInfo);
1884      cast<InvokeInst>(I)->setAttributes(PAL);
1885      break;
1886    }
1887    case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
1888      I = new UnwindInst();
1889      break;
1890    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
1891      I = new UnreachableInst();
1892      break;
1893    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
1894      if (Record.size() < 1 || ((Record.size()-1)&1))
1895        return Error("Invalid PHI record");
1896      const Type *Ty = getTypeByID(Record[0]);
1897      if (!Ty) return Error("Invalid PHI record");
1898
1899      PHINode *PN = PHINode::Create(Ty);
1900      PN->reserveOperandSpace((Record.size()-1)/2);
1901
1902      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
1903        Value *V = getFnValueByID(Record[1+i], Ty);
1904        BasicBlock *BB = getBasicBlock(Record[2+i]);
1905        if (!V || !BB) return Error("Invalid PHI record");
1906        PN->addIncoming(V, BB);
1907      }
1908      I = PN;
1909      break;
1910    }
1911
1912    case bitc::FUNC_CODE_INST_MALLOC: { // MALLOC: [instty, op, align]
1913      if (Record.size() < 3)
1914        return Error("Invalid MALLOC record");
1915      const PointerType *Ty =
1916        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1917      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1918      unsigned Align = Record[2];
1919      if (!Ty || !Size) return Error("Invalid MALLOC record");
1920      I = new MallocInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1921      break;
1922    }
1923    case bitc::FUNC_CODE_INST_FREE: { // FREE: [op, opty]
1924      unsigned OpNum = 0;
1925      Value *Op;
1926      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1927          OpNum != Record.size())
1928        return Error("Invalid FREE record");
1929      I = new FreeInst(Op);
1930      break;
1931    }
1932    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, op, align]
1933      if (Record.size() < 3)
1934        return Error("Invalid ALLOCA record");
1935      const PointerType *Ty =
1936        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
1937      Value *Size = getFnValueByID(Record[1], Type::Int32Ty);
1938      unsigned Align = Record[2];
1939      if (!Ty || !Size) return Error("Invalid ALLOCA record");
1940      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
1941      break;
1942    }
1943    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
1944      unsigned OpNum = 0;
1945      Value *Op;
1946      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
1947          OpNum+2 != Record.size())
1948        return Error("Invalid LOAD record");
1949
1950      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1951      break;
1952    }
1953    case bitc::FUNC_CODE_INST_STORE2: { // STORE2:[ptrty, ptr, val, align, vol]
1954      unsigned OpNum = 0;
1955      Value *Val, *Ptr;
1956      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
1957          getValue(Record, OpNum,
1958                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
1959          OpNum+2 != Record.size())
1960        return Error("Invalid STORE record");
1961
1962      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1963      break;
1964    }
1965    case bitc::FUNC_CODE_INST_STORE: { // STORE:[val, valty, ptr, align, vol]
1966      // FIXME: Legacy form of store instruction. Should be removed in LLVM 3.0.
1967      unsigned OpNum = 0;
1968      Value *Val, *Ptr;
1969      if (getValueTypePair(Record, OpNum, NextValueNo, Val) ||
1970          getValue(Record, OpNum,
1971                   PointerType::getUnqual(Val->getType()), Ptr)||
1972          OpNum+2 != Record.size())
1973        return Error("Invalid STORE record");
1974
1975      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
1976      break;
1977    }
1978    case bitc::FUNC_CODE_INST_CALL: {
1979      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
1980      if (Record.size() < 3)
1981        return Error("Invalid CALL record");
1982
1983      AttrListPtr PAL = getAttributes(Record[0]);
1984      unsigned CCInfo = Record[1];
1985
1986      unsigned OpNum = 2;
1987      Value *Callee;
1988      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
1989        return Error("Invalid CALL record");
1990
1991      const PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
1992      const FunctionType *FTy = 0;
1993      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
1994      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
1995        return Error("Invalid CALL record");
1996
1997      SmallVector<Value*, 16> Args;
1998      // Read the fixed params.
1999      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
2000        if (FTy->getParamType(i)->getTypeID()==Type::LabelTyID)
2001          Args.push_back(getBasicBlock(Record[OpNum]));
2002        else
2003          Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
2004        if (Args.back() == 0) return Error("Invalid CALL record");
2005      }
2006
2007      // Read type/value pairs for varargs params.
2008      if (!FTy->isVarArg()) {
2009        if (OpNum != Record.size())
2010          return Error("Invalid CALL record");
2011      } else {
2012        while (OpNum != Record.size()) {
2013          Value *Op;
2014          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2015            return Error("Invalid CALL record");
2016          Args.push_back(Op);
2017        }
2018      }
2019
2020      I = CallInst::Create(Callee, Args.begin(), Args.end());
2021      cast<CallInst>(I)->setCallingConv(CCInfo>>1);
2022      cast<CallInst>(I)->setTailCall(CCInfo & 1);
2023      cast<CallInst>(I)->setAttributes(PAL);
2024      break;
2025    }
2026    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
2027      if (Record.size() < 3)
2028        return Error("Invalid VAARG record");
2029      const Type *OpTy = getTypeByID(Record[0]);
2030      Value *Op = getFnValueByID(Record[1], OpTy);
2031      const Type *ResTy = getTypeByID(Record[2]);
2032      if (!OpTy || !Op || !ResTy)
2033        return Error("Invalid VAARG record");
2034      I = new VAArgInst(Op, ResTy);
2035      break;
2036    }
2037    }
2038
2039    // Add instruction to end of current BB.  If there is no current BB, reject
2040    // this file.
2041    if (CurBB == 0) {
2042      delete I;
2043      return Error("Invalid instruction with no BB");
2044    }
2045    CurBB->getInstList().push_back(I);
2046
2047    // If this was a terminator instruction, move to the next block.
2048    if (isa<TerminatorInst>(I)) {
2049      ++CurBBNo;
2050      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
2051    }
2052
2053    // Non-void values get registered in the value table for future use.
2054    if (I && I->getType() != Type::VoidTy)
2055      ValueList.AssignValue(I, NextValueNo++);
2056  }
2057
2058  // Check the function list for unresolved values.
2059  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
2060    if (A->getParent() == 0) {
2061      // We found at least one unresolved value.  Nuke them all to avoid leaks.
2062      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
2063        if ((A = dyn_cast<Argument>(ValueList.back())) && A->getParent() == 0) {
2064          A->replaceAllUsesWith(UndefValue::get(A->getType()));
2065          delete A;
2066        }
2067      }
2068      return Error("Never resolved value found in function!");
2069    }
2070  }
2071
2072  // Trim the value list down to the size it was before we parsed this function.
2073  ValueList.shrinkTo(ModuleValueListSize);
2074  std::vector<BasicBlock*>().swap(FunctionBBs);
2075
2076  return false;
2077}
2078
2079//===----------------------------------------------------------------------===//
2080// ModuleProvider implementation
2081//===----------------------------------------------------------------------===//
2082
2083
2084bool BitcodeReader::materializeFunction(Function *F, std::string *ErrInfo) {
2085  // If it already is material, ignore the request.
2086  if (!F->hasNotBeenReadFromBitcode()) return false;
2087
2088  DenseMap<Function*, std::pair<uint64_t, unsigned> >::iterator DFII =
2089    DeferredFunctionInfo.find(F);
2090  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
2091
2092  // Move the bit stream to the saved position of the deferred function body and
2093  // restore the real linkage type for the function.
2094  Stream.JumpToBit(DFII->second.first);
2095  F->setLinkage((GlobalValue::LinkageTypes)DFII->second.second);
2096
2097  if (ParseFunctionBody(F)) {
2098    if (ErrInfo) *ErrInfo = ErrorString;
2099    return true;
2100  }
2101
2102  // Upgrade any old intrinsic calls in the function.
2103  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
2104       E = UpgradedIntrinsics.end(); I != E; ++I) {
2105    if (I->first != I->second) {
2106      for (Value::use_iterator UI = I->first->use_begin(),
2107           UE = I->first->use_end(); UI != UE; ) {
2108        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2109          UpgradeIntrinsicCall(CI, I->second);
2110      }
2111    }
2112  }
2113
2114  return false;
2115}
2116
2117void BitcodeReader::dematerializeFunction(Function *F) {
2118  // If this function isn't materialized, or if it is a proto, this is a noop.
2119  if (F->hasNotBeenReadFromBitcode() || F->isDeclaration())
2120    return;
2121
2122  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
2123
2124  // Just forget the function body, we can remat it later.
2125  F->deleteBody();
2126  F->setLinkage(GlobalValue::GhostLinkage);
2127}
2128
2129
2130Module *BitcodeReader::materializeModule(std::string *ErrInfo) {
2131  // Iterate over the module, deserializing any functions that are still on
2132  // disk.
2133  for (Module::iterator F = TheModule->begin(), E = TheModule->end();
2134       F != E; ++F)
2135    if (F->hasNotBeenReadFromBitcode() &&
2136        materializeFunction(F, ErrInfo))
2137      return 0;
2138
2139  // Upgrade any intrinsic calls that slipped through (should not happen!) and
2140  // delete the old functions to clean up. We can't do this unless the entire
2141  // module is materialized because there could always be another function body
2142  // with calls to the old function.
2143  for (std::vector<std::pair<Function*, Function*> >::iterator I =
2144       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
2145    if (I->first != I->second) {
2146      for (Value::use_iterator UI = I->first->use_begin(),
2147           UE = I->first->use_end(); UI != UE; ) {
2148        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2149          UpgradeIntrinsicCall(CI, I->second);
2150      }
2151      if (!I->first->use_empty())
2152        I->first->replaceAllUsesWith(I->second);
2153      I->first->eraseFromParent();
2154    }
2155  }
2156  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
2157
2158  return TheModule;
2159}
2160
2161
2162/// This method is provided by the parent ModuleProvde class and overriden
2163/// here. It simply releases the module from its provided and frees up our
2164/// state.
2165/// @brief Release our hold on the generated module
2166Module *BitcodeReader::releaseModule(std::string *ErrInfo) {
2167  // Since we're losing control of this Module, we must hand it back complete
2168  Module *M = ModuleProvider::releaseModule(ErrInfo);
2169  FreeState();
2170  return M;
2171}
2172
2173
2174//===----------------------------------------------------------------------===//
2175// External interface
2176//===----------------------------------------------------------------------===//
2177
2178/// getBitcodeModuleProvider - lazy function-at-a-time loading from a file.
2179///
2180ModuleProvider *llvm::getBitcodeModuleProvider(MemoryBuffer *Buffer,
2181                                               LLVMContext& Context,
2182                                               std::string *ErrMsg) {
2183  BitcodeReader *R = new BitcodeReader(Buffer, Context);
2184  if (R->ParseBitcode()) {
2185    if (ErrMsg)
2186      *ErrMsg = R->getErrorString();
2187
2188    // Don't let the BitcodeReader dtor delete 'Buffer'.
2189    R->releaseMemoryBuffer();
2190    delete R;
2191    return 0;
2192  }
2193  return R;
2194}
2195
2196/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
2197/// If an error occurs, return null and fill in *ErrMsg if non-null.
2198Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, LLVMContext& Context,
2199                               std::string *ErrMsg){
2200  BitcodeReader *R;
2201  R = static_cast<BitcodeReader*>(getBitcodeModuleProvider(Buffer, Context,
2202                                                           ErrMsg));
2203  if (!R) return 0;
2204
2205  // Read in the entire module.
2206  Module *M = R->materializeModule(ErrMsg);
2207
2208  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
2209  // there was an error.
2210  R->releaseMemoryBuffer();
2211
2212  // If there was no error, tell ModuleProvider not to delete it when its dtor
2213  // is run.
2214  if (M)
2215    M = R->releaseModule(ErrMsg);
2216
2217  delete R;
2218  return M;
2219}
2220