BitcodeReader.cpp revision 702cc91aa1bd41540e8674921ae7ac89a4ff061f 
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/IntrinsicInst.h"
20#include "llvm/Module.h"
21#include "llvm/Operator.h"
22#include "llvm/AutoUpgrade.h"
23#include "llvm/ADT/SmallString.h"
24#include "llvm/ADT/SmallVector.h"
25#include "llvm/Support/DataStream.h"
26#include "llvm/Support/MathExtras.h"
27#include "llvm/Support/MemoryBuffer.h"
28#include "llvm/OperandTraits.h"
29using namespace llvm;
30
31enum {
32  SWITCH_INST_MAGIC = 0x4B5 // May 2012 => 1205 => Hex
33};
34
35void BitcodeReader::materializeForwardReferencedFunctions() {
36  while (!BlockAddrFwdRefs.empty()) {
37    Function *F = BlockAddrFwdRefs.begin()->first;
38    F->Materialize();
39  }
40}
41
42void BitcodeReader::FreeState() {
43  if (BufferOwned)
44    delete Buffer;
45  Buffer = 0;
46  std::vector<Type*>().swap(TypeList);
47  ValueList.clear();
48  MDValueList.clear();
49
50  std::vector<AttrListPtr>().swap(MAttributes);
51  std::vector<BasicBlock*>().swap(FunctionBBs);
52  std::vector<Function*>().swap(FunctionsWithBodies);
53  DeferredFunctionInfo.clear();
54  MDKindMap.clear();
55
56  assert(BlockAddrFwdRefs.empty() && "Unresolved blockaddress fwd references");
57}
58
59//===----------------------------------------------------------------------===//
60//  Helper functions to implement forward reference resolution, etc.
61//===----------------------------------------------------------------------===//
62
63/// ConvertToString - Convert a string from a record into an std::string, return
64/// true on failure.
65template<typename StrTy>
66static bool ConvertToString(ArrayRef<uint64_t> Record, unsigned Idx,
67                            StrTy &Result) {
68  if (Idx > Record.size())
69    return true;
70
71  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
72    Result += (char)Record[i];
73  return false;
74}
75
76static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
77  switch (Val) {
78  default: // Map unknown/new linkages to external
79  case 0:  return GlobalValue::ExternalLinkage;
80  case 1:  return GlobalValue::WeakAnyLinkage;
81  case 2:  return GlobalValue::AppendingLinkage;
82  case 3:  return GlobalValue::InternalLinkage;
83  case 4:  return GlobalValue::LinkOnceAnyLinkage;
84  case 5:  return GlobalValue::DLLImportLinkage;
85  case 6:  return GlobalValue::DLLExportLinkage;
86  case 7:  return GlobalValue::ExternalWeakLinkage;
87  case 8:  return GlobalValue::CommonLinkage;
88  case 9:  return GlobalValue::PrivateLinkage;
89  case 10: return GlobalValue::WeakODRLinkage;
90  case 11: return GlobalValue::LinkOnceODRLinkage;
91  case 12: return GlobalValue::AvailableExternallyLinkage;
92  case 13: return GlobalValue::LinkerPrivateLinkage;
93  case 14: return GlobalValue::LinkerPrivateWeakLinkage;
94  case 15: return GlobalValue::LinkOnceODRAutoHideLinkage;
95  }
96}
97
98static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
99  switch (Val) {
100  default: // Map unknown visibilities to default.
101  case 0: return GlobalValue::DefaultVisibility;
102  case 1: return GlobalValue::HiddenVisibility;
103  case 2: return GlobalValue::ProtectedVisibility;
104  }
105}
106
107static GlobalVariable::ThreadLocalMode GetDecodedThreadLocalMode(unsigned Val) {
108  switch (Val) {
109    case 0: return GlobalVariable::NotThreadLocal;
110    default: // Map unknown non-zero value to general dynamic.
111    case 1: return GlobalVariable::GeneralDynamicTLSModel;
112    case 2: return GlobalVariable::LocalDynamicTLSModel;
113    case 3: return GlobalVariable::InitialExecTLSModel;
114    case 4: return GlobalVariable::LocalExecTLSModel;
115  }
116}
117
118static int GetDecodedCastOpcode(unsigned Val) {
119  switch (Val) {
120  default: return -1;
121  case bitc::CAST_TRUNC   : return Instruction::Trunc;
122  case bitc::CAST_ZEXT    : return Instruction::ZExt;
123  case bitc::CAST_SEXT    : return Instruction::SExt;
124  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
125  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
126  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
127  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
128  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
129  case bitc::CAST_FPEXT   : return Instruction::FPExt;
130  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
131  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
132  case bitc::CAST_BITCAST : return Instruction::BitCast;
133  }
134}
135static int GetDecodedBinaryOpcode(unsigned Val, Type *Ty) {
136  switch (Val) {
137  default: return -1;
138  case bitc::BINOP_ADD:
139    return Ty->isFPOrFPVectorTy() ? Instruction::FAdd : Instruction::Add;
140  case bitc::BINOP_SUB:
141    return Ty->isFPOrFPVectorTy() ? Instruction::FSub : Instruction::Sub;
142  case bitc::BINOP_MUL:
143    return Ty->isFPOrFPVectorTy() ? Instruction::FMul : Instruction::Mul;
144  case bitc::BINOP_UDIV: return Instruction::UDiv;
145  case bitc::BINOP_SDIV:
146    return Ty->isFPOrFPVectorTy() ? Instruction::FDiv : Instruction::SDiv;
147  case bitc::BINOP_UREM: return Instruction::URem;
148  case bitc::BINOP_SREM:
149    return Ty->isFPOrFPVectorTy() ? Instruction::FRem : Instruction::SRem;
150  case bitc::BINOP_SHL:  return Instruction::Shl;
151  case bitc::BINOP_LSHR: return Instruction::LShr;
152  case bitc::BINOP_ASHR: return Instruction::AShr;
153  case bitc::BINOP_AND:  return Instruction::And;
154  case bitc::BINOP_OR:   return Instruction::Or;
155  case bitc::BINOP_XOR:  return Instruction::Xor;
156  }
157}
158
159static AtomicRMWInst::BinOp GetDecodedRMWOperation(unsigned Val) {
160  switch (Val) {
161  default: return AtomicRMWInst::BAD_BINOP;
162  case bitc::RMW_XCHG: return AtomicRMWInst::Xchg;
163  case bitc::RMW_ADD: return AtomicRMWInst::Add;
164  case bitc::RMW_SUB: return AtomicRMWInst::Sub;
165  case bitc::RMW_AND: return AtomicRMWInst::And;
166  case bitc::RMW_NAND: return AtomicRMWInst::Nand;
167  case bitc::RMW_OR: return AtomicRMWInst::Or;
168  case bitc::RMW_XOR: return AtomicRMWInst::Xor;
169  case bitc::RMW_MAX: return AtomicRMWInst::Max;
170  case bitc::RMW_MIN: return AtomicRMWInst::Min;
171  case bitc::RMW_UMAX: return AtomicRMWInst::UMax;
172  case bitc::RMW_UMIN: return AtomicRMWInst::UMin;
173  }
174}
175
176static AtomicOrdering GetDecodedOrdering(unsigned Val) {
177  switch (Val) {
178  case bitc::ORDERING_NOTATOMIC: return NotAtomic;
179  case bitc::ORDERING_UNORDERED: return Unordered;
180  case bitc::ORDERING_MONOTONIC: return Monotonic;
181  case bitc::ORDERING_ACQUIRE: return Acquire;
182  case bitc::ORDERING_RELEASE: return Release;
183  case bitc::ORDERING_ACQREL: return AcquireRelease;
184  default: // Map unknown orderings to sequentially-consistent.
185  case bitc::ORDERING_SEQCST: return SequentiallyConsistent;
186  }
187}
188
189static SynchronizationScope GetDecodedSynchScope(unsigned Val) {
190  switch (Val) {
191  case bitc::SYNCHSCOPE_SINGLETHREAD: return SingleThread;
192  default: // Map unknown scopes to cross-thread.
193  case bitc::SYNCHSCOPE_CROSSTHREAD: return CrossThread;
194  }
195}
196
197namespace llvm {
198namespace {
199  /// @brief A class for maintaining the slot number definition
200  /// as a placeholder for the actual definition for forward constants defs.
201  class ConstantPlaceHolder : public ConstantExpr {
202    void operator=(const ConstantPlaceHolder &) LLVM_DELETED_FUNCTION;
203  public:
204    // allocate space for exactly one operand
205    void *operator new(size_t s) {
206      return User::operator new(s, 1);
207    }
208    explicit ConstantPlaceHolder(Type *Ty, LLVMContext& Context)
209      : ConstantExpr(Ty, Instruction::UserOp1, &Op<0>(), 1) {
210      Op<0>() = UndefValue::get(Type::getInt32Ty(Context));
211    }
212
213    /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
214    static bool classof(const Value *V) {
215      return isa<ConstantExpr>(V) &&
216             cast<ConstantExpr>(V)->getOpcode() == Instruction::UserOp1;
217    }
218
219
220    /// Provide fast operand accessors
221    //DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
222  };
223}
224
225// FIXME: can we inherit this from ConstantExpr?
226template <>
227struct OperandTraits<ConstantPlaceHolder> :
228  public FixedNumOperandTraits<ConstantPlaceHolder, 1> {
229};
230}
231
232
233void BitcodeReaderValueList::AssignValue(Value *V, unsigned Idx) {
234  if (Idx == size()) {
235    push_back(V);
236    return;
237  }
238
239  if (Idx >= size())
240    resize(Idx+1);
241
242  WeakVH &OldV = ValuePtrs[Idx];
243  if (OldV == 0) {
244    OldV = V;
245    return;
246  }
247
248  // Handle constants and non-constants (e.g. instrs) differently for
249  // efficiency.
250  if (Constant *PHC = dyn_cast<Constant>(&*OldV)) {
251    ResolveConstants.push_back(std::make_pair(PHC, Idx));
252    OldV = V;
253  } else {
254    // If there was a forward reference to this value, replace it.
255    Value *PrevVal = OldV;
256    OldV->replaceAllUsesWith(V);
257    delete PrevVal;
258  }
259}
260
261
262Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
263                                                    Type *Ty) {
264  if (Idx >= size())
265    resize(Idx + 1);
266
267  if (Value *V = ValuePtrs[Idx]) {
268    assert(Ty == V->getType() && "Type mismatch in constant table!");
269    return cast<Constant>(V);
270  }
271
272  // Create and return a placeholder, which will later be RAUW'd.
273  Constant *C = new ConstantPlaceHolder(Ty, Context);
274  ValuePtrs[Idx] = C;
275  return C;
276}
277
278Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, Type *Ty) {
279  if (Idx >= size())
280    resize(Idx + 1);
281
282  if (Value *V = ValuePtrs[Idx]) {
283    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
284    return V;
285  }
286
287  // No type specified, must be invalid reference.
288  if (Ty == 0) return 0;
289
290  // Create and return a placeholder, which will later be RAUW'd.
291  Value *V = new Argument(Ty);
292  ValuePtrs[Idx] = V;
293  return V;
294}
295
296/// ResolveConstantForwardRefs - Once all constants are read, this method bulk
297/// resolves any forward references.  The idea behind this is that we sometimes
298/// get constants (such as large arrays) which reference *many* forward ref
299/// constants.  Replacing each of these causes a lot of thrashing when
300/// building/reuniquing the constant.  Instead of doing this, we look at all the
301/// uses and rewrite all the place holders at once for any constant that uses
302/// a placeholder.
303void BitcodeReaderValueList::ResolveConstantForwardRefs() {
304  // Sort the values by-pointer so that they are efficient to look up with a
305  // binary search.
306  std::sort(ResolveConstants.begin(), ResolveConstants.end());
307
308  SmallVector<Constant*, 64> NewOps;
309
310  while (!ResolveConstants.empty()) {
311    Value *RealVal = operator[](ResolveConstants.back().second);
312    Constant *Placeholder = ResolveConstants.back().first;
313    ResolveConstants.pop_back();
314
315    // Loop over all users of the placeholder, updating them to reference the
316    // new value.  If they reference more than one placeholder, update them all
317    // at once.
318    while (!Placeholder->use_empty()) {
319      Value::use_iterator UI = Placeholder->use_begin();
320      User *U = *UI;
321
322      // If the using object isn't uniqued, just update the operands.  This
323      // handles instructions and initializers for global variables.
324      if (!isa<Constant>(U) || isa<GlobalValue>(U)) {
325        UI.getUse().set(RealVal);
326        continue;
327      }
328
329      // Otherwise, we have a constant that uses the placeholder.  Replace that
330      // constant with a new constant that has *all* placeholder uses updated.
331      Constant *UserC = cast<Constant>(U);
332      for (User::op_iterator I = UserC->op_begin(), E = UserC->op_end();
333           I != E; ++I) {
334        Value *NewOp;
335        if (!isa<ConstantPlaceHolder>(*I)) {
336          // Not a placeholder reference.
337          NewOp = *I;
338        } else if (*I == Placeholder) {
339          // Common case is that it just references this one placeholder.
340          NewOp = RealVal;
341        } else {
342          // Otherwise, look up the placeholder in ResolveConstants.
343          ResolveConstantsTy::iterator It =
344            std::lower_bound(ResolveConstants.begin(), ResolveConstants.end(),
345                             std::pair<Constant*, unsigned>(cast<Constant>(*I),
346                                                            0));
347          assert(It != ResolveConstants.end() && It->first == *I);
348          NewOp = operator[](It->second);
349        }
350
351        NewOps.push_back(cast<Constant>(NewOp));
352      }
353
354      // Make the new constant.
355      Constant *NewC;
356      if (ConstantArray *UserCA = dyn_cast<ConstantArray>(UserC)) {
357        NewC = ConstantArray::get(UserCA->getType(), NewOps);
358      } else if (ConstantStruct *UserCS = dyn_cast<ConstantStruct>(UserC)) {
359        NewC = ConstantStruct::get(UserCS->getType(), NewOps);
360      } else if (isa<ConstantVector>(UserC)) {
361        NewC = ConstantVector::get(NewOps);
362      } else {
363        assert(isa<ConstantExpr>(UserC) && "Must be a ConstantExpr.");
364        NewC = cast<ConstantExpr>(UserC)->getWithOperands(NewOps);
365      }
366
367      UserC->replaceAllUsesWith(NewC);
368      UserC->destroyConstant();
369      NewOps.clear();
370    }
371
372    // Update all ValueHandles, they should be the only users at this point.
373    Placeholder->replaceAllUsesWith(RealVal);
374    delete Placeholder;
375  }
376}
377
378void BitcodeReaderMDValueList::AssignValue(Value *V, unsigned Idx) {
379  if (Idx == size()) {
380    push_back(V);
381    return;
382  }
383
384  if (Idx >= size())
385    resize(Idx+1);
386
387  WeakVH &OldV = MDValuePtrs[Idx];
388  if (OldV == 0) {
389    OldV = V;
390    return;
391  }
392
393  // If there was a forward reference to this value, replace it.
394  MDNode *PrevVal = cast<MDNode>(OldV);
395  OldV->replaceAllUsesWith(V);
396  MDNode::deleteTemporary(PrevVal);
397  // Deleting PrevVal sets Idx value in MDValuePtrs to null. Set new
398  // value for Idx.
399  MDValuePtrs[Idx] = V;
400}
401
402Value *BitcodeReaderMDValueList::getValueFwdRef(unsigned Idx) {
403  if (Idx >= size())
404    resize(Idx + 1);
405
406  if (Value *V = MDValuePtrs[Idx]) {
407    assert(V->getType()->isMetadataTy() && "Type mismatch in value table!");
408    return V;
409  }
410
411  // Create and return a placeholder, which will later be RAUW'd.
412  Value *V = MDNode::getTemporary(Context, ArrayRef<Value*>());
413  MDValuePtrs[Idx] = V;
414  return V;
415}
416
417Type *BitcodeReader::getTypeByID(unsigned ID) {
418  // The type table size is always specified correctly.
419  if (ID >= TypeList.size())
420    return 0;
421
422  if (Type *Ty = TypeList[ID])
423    return Ty;
424
425  // If we have a forward reference, the only possible case is when it is to a
426  // named struct.  Just create a placeholder for now.
427  return TypeList[ID] = StructType::create(Context);
428}
429
430
431//===----------------------------------------------------------------------===//
432//  Functions for parsing blocks from the bitcode file
433//===----------------------------------------------------------------------===//
434
435bool BitcodeReader::ParseAttributeBlock() {
436  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
437    return Error("Malformed block record");
438
439  if (!MAttributes.empty())
440    return Error("Multiple PARAMATTR blocks found!");
441
442  SmallVector<uint64_t, 64> Record;
443
444  SmallVector<AttributeWithIndex, 8> Attrs;
445
446  // Read all the records.
447  while (1) {
448    unsigned Code = Stream.ReadCode();
449    if (Code == bitc::END_BLOCK) {
450      if (Stream.ReadBlockEnd())
451        return Error("Error at end of PARAMATTR block");
452      return false;
453    }
454
455    if (Code == bitc::ENTER_SUBBLOCK) {
456      // No known subblocks, always skip them.
457      Stream.ReadSubBlockID();
458      if (Stream.SkipBlock())
459        return Error("Malformed block record");
460      continue;
461    }
462
463    if (Code == bitc::DEFINE_ABBREV) {
464      Stream.ReadAbbrevRecord();
465      continue;
466    }
467
468    // Read a record.
469    Record.clear();
470    switch (Stream.ReadRecord(Code, Record)) {
471    default:  // Default behavior: ignore.
472      break;
473    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
474      if (Record.size() & 1)
475        return Error("Invalid ENTRY record");
476
477      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
478        Attributes ReconstitutedAttr =
479          Attributes::decodeLLVMAttributesForBitcode(Context, Record[i+1]);
480        Record[i+1] = ReconstitutedAttr.Raw();
481      }
482
483      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
484        AttrBuilder B(Record[i+1]);
485        if (B.hasAttributes())
486          Attrs.push_back(AttributeWithIndex::get(Record[i],
487                                                  Attributes::get(Context, B)));
488      }
489
490      MAttributes.push_back(AttrListPtr::get(Attrs));
491      Attrs.clear();
492      break;
493    }
494    }
495  }
496}
497
498bool BitcodeReader::ParseTypeTable() {
499  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID_NEW))
500    return Error("Malformed block record");
501
502  return ParseTypeTableBody();
503}
504
505bool BitcodeReader::ParseTypeTableBody() {
506  if (!TypeList.empty())
507    return Error("Multiple TYPE_BLOCKs found!");
508
509  SmallVector<uint64_t, 64> Record;
510  unsigned NumRecords = 0;
511
512  SmallString<64> TypeName;
513
514  // Read all the records for this type table.
515  while (1) {
516    unsigned Code = Stream.ReadCode();
517    if (Code == bitc::END_BLOCK) {
518      if (NumRecords != TypeList.size())
519        return Error("Invalid type forward reference in TYPE_BLOCK");
520      if (Stream.ReadBlockEnd())
521        return Error("Error at end of type table block");
522      return false;
523    }
524
525    if (Code == bitc::ENTER_SUBBLOCK) {
526      // No known subblocks, always skip them.
527      Stream.ReadSubBlockID();
528      if (Stream.SkipBlock())
529        return Error("Malformed block record");
530      continue;
531    }
532
533    if (Code == bitc::DEFINE_ABBREV) {
534      Stream.ReadAbbrevRecord();
535      continue;
536    }
537
538    // Read a record.
539    Record.clear();
540    Type *ResultTy = 0;
541    switch (Stream.ReadRecord(Code, Record)) {
542    default: return Error("unknown type in type table");
543    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
544      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
545      // type list.  This allows us to reserve space.
546      if (Record.size() < 1)
547        return Error("Invalid TYPE_CODE_NUMENTRY record");
548      TypeList.resize(Record[0]);
549      continue;
550    case bitc::TYPE_CODE_VOID:      // VOID
551      ResultTy = Type::getVoidTy(Context);
552      break;
553    case bitc::TYPE_CODE_HALF:     // HALF
554      ResultTy = Type::getHalfTy(Context);
555      break;
556    case bitc::TYPE_CODE_FLOAT:     // FLOAT
557      ResultTy = Type::getFloatTy(Context);
558      break;
559    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
560      ResultTy = Type::getDoubleTy(Context);
561      break;
562    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
563      ResultTy = Type::getX86_FP80Ty(Context);
564      break;
565    case bitc::TYPE_CODE_FP128:     // FP128
566      ResultTy = Type::getFP128Ty(Context);
567      break;
568    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
569      ResultTy = Type::getPPC_FP128Ty(Context);
570      break;
571    case bitc::TYPE_CODE_LABEL:     // LABEL
572      ResultTy = Type::getLabelTy(Context);
573      break;
574    case bitc::TYPE_CODE_METADATA:  // METADATA
575      ResultTy = Type::getMetadataTy(Context);
576      break;
577    case bitc::TYPE_CODE_X86_MMX:   // X86_MMX
578      ResultTy = Type::getX86_MMXTy(Context);
579      break;
580    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
581      if (Record.size() < 1)
582        return Error("Invalid Integer type record");
583
584      ResultTy = IntegerType::get(Context, Record[0]);
585      break;
586    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
587                                    //          [pointee type, address space]
588      if (Record.size() < 1)
589        return Error("Invalid POINTER type record");
590      unsigned AddressSpace = 0;
591      if (Record.size() == 2)
592        AddressSpace = Record[1];
593      ResultTy = getTypeByID(Record[0]);
594      if (ResultTy == 0) return Error("invalid element type in pointer type");
595      ResultTy = PointerType::get(ResultTy, AddressSpace);
596      break;
597    }
598    case bitc::TYPE_CODE_FUNCTION_OLD: {
599      // FIXME: attrid is dead, remove it in LLVM 4.0
600      // FUNCTION: [vararg, attrid, retty, paramty x N]
601      if (Record.size() < 3)
602        return Error("Invalid FUNCTION type record");
603      SmallVector<Type*, 8> ArgTys;
604      for (unsigned i = 3, e = Record.size(); i != e; ++i) {
605        if (Type *T = getTypeByID(Record[i]))
606          ArgTys.push_back(T);
607        else
608          break;
609      }
610
611      ResultTy = getTypeByID(Record[2]);
612      if (ResultTy == 0 || ArgTys.size() < Record.size()-3)
613        return Error("invalid type in function type");
614
615      ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
616      break;
617    }
618    case bitc::TYPE_CODE_FUNCTION: {
619      // FUNCTION: [vararg, retty, paramty x N]
620      if (Record.size() < 2)
621        return Error("Invalid FUNCTION type record");
622      SmallVector<Type*, 8> ArgTys;
623      for (unsigned i = 2, e = Record.size(); i != e; ++i) {
624        if (Type *T = getTypeByID(Record[i]))
625          ArgTys.push_back(T);
626        else
627          break;
628      }
629
630      ResultTy = getTypeByID(Record[1]);
631      if (ResultTy == 0 || ArgTys.size() < Record.size()-2)
632        return Error("invalid type in function type");
633
634      ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
635      break;
636    }
637    case bitc::TYPE_CODE_STRUCT_ANON: {  // STRUCT: [ispacked, eltty x N]
638      if (Record.size() < 1)
639        return Error("Invalid STRUCT type record");
640      SmallVector<Type*, 8> EltTys;
641      for (unsigned i = 1, e = Record.size(); i != e; ++i) {
642        if (Type *T = getTypeByID(Record[i]))
643          EltTys.push_back(T);
644        else
645          break;
646      }
647      if (EltTys.size() != Record.size()-1)
648        return Error("invalid type in struct type");
649      ResultTy = StructType::get(Context, EltTys, Record[0]);
650      break;
651    }
652    case bitc::TYPE_CODE_STRUCT_NAME:   // STRUCT_NAME: [strchr x N]
653      if (ConvertToString(Record, 0, TypeName))
654        return Error("Invalid STRUCT_NAME record");
655      continue;
656
657    case bitc::TYPE_CODE_STRUCT_NAMED: { // STRUCT: [ispacked, eltty x N]
658      if (Record.size() < 1)
659        return Error("Invalid STRUCT type record");
660
661      if (NumRecords >= TypeList.size())
662        return Error("invalid TYPE table");
663
664      // Check to see if this was forward referenced, if so fill in the temp.
665      StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
666      if (Res) {
667        Res->setName(TypeName);
668        TypeList[NumRecords] = 0;
669      } else  // Otherwise, create a new struct.
670        Res = StructType::create(Context, TypeName);
671      TypeName.clear();
672
673      SmallVector<Type*, 8> EltTys;
674      for (unsigned i = 1, e = Record.size(); i != e; ++i) {
675        if (Type *T = getTypeByID(Record[i]))
676          EltTys.push_back(T);
677        else
678          break;
679      }
680      if (EltTys.size() != Record.size()-1)
681        return Error("invalid STRUCT type record");
682      Res->setBody(EltTys, Record[0]);
683      ResultTy = Res;
684      break;
685    }
686    case bitc::TYPE_CODE_OPAQUE: {       // OPAQUE: []
687      if (Record.size() != 1)
688        return Error("Invalid OPAQUE type record");
689
690      if (NumRecords >= TypeList.size())
691        return Error("invalid TYPE table");
692
693      // Check to see if this was forward referenced, if so fill in the temp.
694      StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
695      if (Res) {
696        Res->setName(TypeName);
697        TypeList[NumRecords] = 0;
698      } else  // Otherwise, create a new struct with no body.
699        Res = StructType::create(Context, TypeName);
700      TypeName.clear();
701      ResultTy = Res;
702      break;
703    }
704    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
705      if (Record.size() < 2)
706        return Error("Invalid ARRAY type record");
707      if ((ResultTy = getTypeByID(Record[1])))
708        ResultTy = ArrayType::get(ResultTy, Record[0]);
709      else
710        return Error("Invalid ARRAY type element");
711      break;
712    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
713      if (Record.size() < 2)
714        return Error("Invalid VECTOR type record");
715      if ((ResultTy = getTypeByID(Record[1])))
716        ResultTy = VectorType::get(ResultTy, Record[0]);
717      else
718        return Error("Invalid ARRAY type element");
719      break;
720    }
721
722    if (NumRecords >= TypeList.size())
723      return Error("invalid TYPE table");
724    assert(ResultTy && "Didn't read a type?");
725    assert(TypeList[NumRecords] == 0 && "Already read type?");
726    TypeList[NumRecords++] = ResultTy;
727  }
728}
729
730bool BitcodeReader::ParseValueSymbolTable() {
731  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
732    return Error("Malformed block record");
733
734  SmallVector<uint64_t, 64> Record;
735
736  // Read all the records for this value table.
737  SmallString<128> ValueName;
738  while (1) {
739    unsigned Code = Stream.ReadCode();
740    if (Code == bitc::END_BLOCK) {
741      if (Stream.ReadBlockEnd())
742        return Error("Error at end of value symbol table block");
743      return false;
744    }
745    if (Code == bitc::ENTER_SUBBLOCK) {
746      // No known subblocks, always skip them.
747      Stream.ReadSubBlockID();
748      if (Stream.SkipBlock())
749        return Error("Malformed block record");
750      continue;
751    }
752
753    if (Code == bitc::DEFINE_ABBREV) {
754      Stream.ReadAbbrevRecord();
755      continue;
756    }
757
758    // Read a record.
759    Record.clear();
760    switch (Stream.ReadRecord(Code, Record)) {
761    default:  // Default behavior: unknown type.
762      break;
763    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
764      if (ConvertToString(Record, 1, ValueName))
765        return Error("Invalid VST_ENTRY record");
766      unsigned ValueID = Record[0];
767      if (ValueID >= ValueList.size())
768        return Error("Invalid Value ID in VST_ENTRY record");
769      Value *V = ValueList[ValueID];
770
771      V->setName(StringRef(ValueName.data(), ValueName.size()));
772      ValueName.clear();
773      break;
774    }
775    case bitc::VST_CODE_BBENTRY: {
776      if (ConvertToString(Record, 1, ValueName))
777        return Error("Invalid VST_BBENTRY record");
778      BasicBlock *BB = getBasicBlock(Record[0]);
779      if (BB == 0)
780        return Error("Invalid BB ID in VST_BBENTRY record");
781
782      BB->setName(StringRef(ValueName.data(), ValueName.size()));
783      ValueName.clear();
784      break;
785    }
786    }
787  }
788}
789
790bool BitcodeReader::ParseMetadata() {
791  unsigned NextMDValueNo = MDValueList.size();
792
793  if (Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
794    return Error("Malformed block record");
795
796  SmallVector<uint64_t, 64> Record;
797
798  // Read all the records.
799  while (1) {
800    unsigned Code = Stream.ReadCode();
801    if (Code == bitc::END_BLOCK) {
802      if (Stream.ReadBlockEnd())
803        return Error("Error at end of PARAMATTR block");
804      return false;
805    }
806
807    if (Code == bitc::ENTER_SUBBLOCK) {
808      // No known subblocks, always skip them.
809      Stream.ReadSubBlockID();
810      if (Stream.SkipBlock())
811        return Error("Malformed block record");
812      continue;
813    }
814
815    if (Code == bitc::DEFINE_ABBREV) {
816      Stream.ReadAbbrevRecord();
817      continue;
818    }
819
820    bool IsFunctionLocal = false;
821    // Read a record.
822    Record.clear();
823    Code = Stream.ReadRecord(Code, Record);
824    switch (Code) {
825    default:  // Default behavior: ignore.
826      break;
827    case bitc::METADATA_NAME: {
828      // Read named of the named metadata.
829      SmallString<8> Name(Record.begin(), Record.end());
830      Record.clear();
831      Code = Stream.ReadCode();
832
833      // METADATA_NAME is always followed by METADATA_NAMED_NODE.
834      unsigned NextBitCode = Stream.ReadRecord(Code, Record);
835      assert(NextBitCode == bitc::METADATA_NAMED_NODE); (void)NextBitCode;
836
837      // Read named metadata elements.
838      unsigned Size = Record.size();
839      NamedMDNode *NMD = TheModule->getOrInsertNamedMetadata(Name);
840      for (unsigned i = 0; i != Size; ++i) {
841        MDNode *MD = dyn_cast<MDNode>(MDValueList.getValueFwdRef(Record[i]));
842        if (MD == 0)
843          return Error("Malformed metadata record");
844        NMD->addOperand(MD);
845      }
846      break;
847    }
848    case bitc::METADATA_FN_NODE:
849      IsFunctionLocal = true;
850      // fall-through
851    case bitc::METADATA_NODE: {
852      if (Record.size() % 2 == 1)
853        return Error("Invalid METADATA_NODE record");
854
855      unsigned Size = Record.size();
856      SmallVector<Value*, 8> Elts;
857      for (unsigned i = 0; i != Size; i += 2) {
858        Type *Ty = getTypeByID(Record[i]);
859        if (!Ty) return Error("Invalid METADATA_NODE record");
860        if (Ty->isMetadataTy())
861          Elts.push_back(MDValueList.getValueFwdRef(Record[i+1]));
862        else if (!Ty->isVoidTy())
863          Elts.push_back(ValueList.getValueFwdRef(Record[i+1], Ty));
864        else
865          Elts.push_back(NULL);
866      }
867      Value *V = MDNode::getWhenValsUnresolved(Context, Elts, IsFunctionLocal);
868      IsFunctionLocal = false;
869      MDValueList.AssignValue(V, NextMDValueNo++);
870      break;
871    }
872    case bitc::METADATA_STRING: {
873      SmallString<8> String(Record.begin(), Record.end());
874      Value *V = MDString::get(Context, String);
875      MDValueList.AssignValue(V, NextMDValueNo++);
876      break;
877    }
878    case bitc::METADATA_KIND: {
879      if (Record.size() < 2)
880        return Error("Invalid METADATA_KIND record");
881
882      unsigned Kind = Record[0];
883      SmallString<8> Name(Record.begin()+1, Record.end());
884
885      unsigned NewKind = TheModule->getMDKindID(Name.str());
886      if (!MDKindMap.insert(std::make_pair(Kind, NewKind)).second)
887        return Error("Conflicting METADATA_KIND records");
888      break;
889    }
890    }
891  }
892}
893
894/// decodeSignRotatedValue - Decode a signed value stored with the sign bit in
895/// the LSB for dense VBR encoding.
896uint64_t BitcodeReader::decodeSignRotatedValue(uint64_t V) {
897  if ((V & 1) == 0)
898    return V >> 1;
899  if (V != 1)
900    return -(V >> 1);
901  // There is no such thing as -0 with integers.  "-0" really means MININT.
902  return 1ULL << 63;
903}
904
905/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
906/// values and aliases that we can.
907bool BitcodeReader::ResolveGlobalAndAliasInits() {
908  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
909  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
910
911  GlobalInitWorklist.swap(GlobalInits);
912  AliasInitWorklist.swap(AliasInits);
913
914  while (!GlobalInitWorklist.empty()) {
915    unsigned ValID = GlobalInitWorklist.back().second;
916    if (ValID >= ValueList.size()) {
917      // Not ready to resolve this yet, it requires something later in the file.
918      GlobalInits.push_back(GlobalInitWorklist.back());
919    } else {
920      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
921        GlobalInitWorklist.back().first->setInitializer(C);
922      else
923        return Error("Global variable initializer is not a constant!");
924    }
925    GlobalInitWorklist.pop_back();
926  }
927
928  while (!AliasInitWorklist.empty()) {
929    unsigned ValID = AliasInitWorklist.back().second;
930    if (ValID >= ValueList.size()) {
931      AliasInits.push_back(AliasInitWorklist.back());
932    } else {
933      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
934        AliasInitWorklist.back().first->setAliasee(C);
935      else
936        return Error("Alias initializer is not a constant!");
937    }
938    AliasInitWorklist.pop_back();
939  }
940  return false;
941}
942
943static APInt ReadWideAPInt(ArrayRef<uint64_t> Vals, unsigned TypeBits) {
944  SmallVector<uint64_t, 8> Words(Vals.size());
945  std::transform(Vals.begin(), Vals.end(), Words.begin(),
946                 BitcodeReader::decodeSignRotatedValue);
947
948  return APInt(TypeBits, Words);
949}
950
951bool BitcodeReader::ParseConstants() {
952  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
953    return Error("Malformed block record");
954
955  SmallVector<uint64_t, 64> Record;
956
957  // Read all the records for this value table.
958  Type *CurTy = Type::getInt32Ty(Context);
959  unsigned NextCstNo = ValueList.size();
960  while (1) {
961    unsigned Code = Stream.ReadCode();
962    if (Code == bitc::END_BLOCK)
963      break;
964
965    if (Code == bitc::ENTER_SUBBLOCK) {
966      // No known subblocks, always skip them.
967      Stream.ReadSubBlockID();
968      if (Stream.SkipBlock())
969        return Error("Malformed block record");
970      continue;
971    }
972
973    if (Code == bitc::DEFINE_ABBREV) {
974      Stream.ReadAbbrevRecord();
975      continue;
976    }
977
978    // Read a record.
979    Record.clear();
980    Value *V = 0;
981    unsigned BitCode = Stream.ReadRecord(Code, Record);
982    switch (BitCode) {
983    default:  // Default behavior: unknown constant
984    case bitc::CST_CODE_UNDEF:     // UNDEF
985      V = UndefValue::get(CurTy);
986      break;
987    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
988      if (Record.empty())
989        return Error("Malformed CST_SETTYPE record");
990      if (Record[0] >= TypeList.size())
991        return Error("Invalid Type ID in CST_SETTYPE record");
992      CurTy = TypeList[Record[0]];
993      continue;  // Skip the ValueList manipulation.
994    case bitc::CST_CODE_NULL:      // NULL
995      V = Constant::getNullValue(CurTy);
996      break;
997    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
998      if (!CurTy->isIntegerTy() || Record.empty())
999        return Error("Invalid CST_INTEGER record");
1000      V = ConstantInt::get(CurTy, decodeSignRotatedValue(Record[0]));
1001      break;
1002    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
1003      if (!CurTy->isIntegerTy() || Record.empty())
1004        return Error("Invalid WIDE_INTEGER record");
1005
1006      APInt VInt = ReadWideAPInt(Record,
1007                                 cast<IntegerType>(CurTy)->getBitWidth());
1008      V = ConstantInt::get(Context, VInt);
1009
1010      break;
1011    }
1012    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
1013      if (Record.empty())
1014        return Error("Invalid FLOAT record");
1015      if (CurTy->isHalfTy())
1016        V = ConstantFP::get(Context, APFloat(APInt(16, (uint16_t)Record[0])));
1017      else if (CurTy->isFloatTy())
1018        V = ConstantFP::get(Context, APFloat(APInt(32, (uint32_t)Record[0])));
1019      else if (CurTy->isDoubleTy())
1020        V = ConstantFP::get(Context, APFloat(APInt(64, Record[0])));
1021      else if (CurTy->isX86_FP80Ty()) {
1022        // Bits are not stored the same way as a normal i80 APInt, compensate.
1023        uint64_t Rearrange[2];
1024        Rearrange[0] = (Record[1] & 0xffffLL) | (Record[0] << 16);
1025        Rearrange[1] = Record[0] >> 48;
1026        V = ConstantFP::get(Context, APFloat(APInt(80, Rearrange)));
1027      } else if (CurTy->isFP128Ty())
1028        V = ConstantFP::get(Context, APFloat(APInt(128, Record), true));
1029      else if (CurTy->isPPC_FP128Ty())
1030        V = ConstantFP::get(Context, APFloat(APInt(128, Record)));
1031      else
1032        V = UndefValue::get(CurTy);
1033      break;
1034    }
1035
1036    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
1037      if (Record.empty())
1038        return Error("Invalid CST_AGGREGATE record");
1039
1040      unsigned Size = Record.size();
1041      SmallVector<Constant*, 16> Elts;
1042
1043      if (StructType *STy = dyn_cast<StructType>(CurTy)) {
1044        for (unsigned i = 0; i != Size; ++i)
1045          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
1046                                                     STy->getElementType(i)));
1047        V = ConstantStruct::get(STy, Elts);
1048      } else if (ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
1049        Type *EltTy = ATy->getElementType();
1050        for (unsigned i = 0; i != Size; ++i)
1051          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1052        V = ConstantArray::get(ATy, Elts);
1053      } else if (VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
1054        Type *EltTy = VTy->getElementType();
1055        for (unsigned i = 0; i != Size; ++i)
1056          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1057        V = ConstantVector::get(Elts);
1058      } else {
1059        V = UndefValue::get(CurTy);
1060      }
1061      break;
1062    }
1063    case bitc::CST_CODE_STRING:    // STRING: [values]
1064    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
1065      if (Record.empty())
1066        return Error("Invalid CST_STRING record");
1067
1068      SmallString<16> Elts(Record.begin(), Record.end());
1069      V = ConstantDataArray::getString(Context, Elts,
1070                                       BitCode == bitc::CST_CODE_CSTRING);
1071      break;
1072    }
1073    case bitc::CST_CODE_DATA: {// DATA: [n x value]
1074      if (Record.empty())
1075        return Error("Invalid CST_DATA record");
1076
1077      Type *EltTy = cast<SequentialType>(CurTy)->getElementType();
1078      unsigned Size = Record.size();
1079
1080      if (EltTy->isIntegerTy(8)) {
1081        SmallVector<uint8_t, 16> Elts(Record.begin(), Record.end());
1082        if (isa<VectorType>(CurTy))
1083          V = ConstantDataVector::get(Context, Elts);
1084        else
1085          V = ConstantDataArray::get(Context, Elts);
1086      } else if (EltTy->isIntegerTy(16)) {
1087        SmallVector<uint16_t, 16> Elts(Record.begin(), Record.end());
1088        if (isa<VectorType>(CurTy))
1089          V = ConstantDataVector::get(Context, Elts);
1090        else
1091          V = ConstantDataArray::get(Context, Elts);
1092      } else if (EltTy->isIntegerTy(32)) {
1093        SmallVector<uint32_t, 16> Elts(Record.begin(), Record.end());
1094        if (isa<VectorType>(CurTy))
1095          V = ConstantDataVector::get(Context, Elts);
1096        else
1097          V = ConstantDataArray::get(Context, Elts);
1098      } else if (EltTy->isIntegerTy(64)) {
1099        SmallVector<uint64_t, 16> Elts(Record.begin(), Record.end());
1100        if (isa<VectorType>(CurTy))
1101          V = ConstantDataVector::get(Context, Elts);
1102        else
1103          V = ConstantDataArray::get(Context, Elts);
1104      } else if (EltTy->isFloatTy()) {
1105        SmallVector<float, 16> Elts(Size);
1106        std::transform(Record.begin(), Record.end(), Elts.begin(), BitsToFloat);
1107        if (isa<VectorType>(CurTy))
1108          V = ConstantDataVector::get(Context, Elts);
1109        else
1110          V = ConstantDataArray::get(Context, Elts);
1111      } else if (EltTy->isDoubleTy()) {
1112        SmallVector<double, 16> Elts(Size);
1113        std::transform(Record.begin(), Record.end(), Elts.begin(),
1114                       BitsToDouble);
1115        if (isa<VectorType>(CurTy))
1116          V = ConstantDataVector::get(Context, Elts);
1117        else
1118          V = ConstantDataArray::get(Context, Elts);
1119      } else {
1120        return Error("Unknown element type in CE_DATA");
1121      }
1122      break;
1123    }
1124
1125    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
1126      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
1127      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
1128      if (Opc < 0) {
1129        V = UndefValue::get(CurTy);  // Unknown binop.
1130      } else {
1131        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
1132        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
1133        unsigned Flags = 0;
1134        if (Record.size() >= 4) {
1135          if (Opc == Instruction::Add ||
1136              Opc == Instruction::Sub ||
1137              Opc == Instruction::Mul ||
1138              Opc == Instruction::Shl) {
1139            if (Record[3] & (1 << bitc::OBO_NO_SIGNED_WRAP))
1140              Flags |= OverflowingBinaryOperator::NoSignedWrap;
1141            if (Record[3] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
1142              Flags |= OverflowingBinaryOperator::NoUnsignedWrap;
1143          } else if (Opc == Instruction::SDiv ||
1144                     Opc == Instruction::UDiv ||
1145                     Opc == Instruction::LShr ||
1146                     Opc == Instruction::AShr) {
1147            if (Record[3] & (1 << bitc::PEO_EXACT))
1148              Flags |= SDivOperator::IsExact;
1149          }
1150        }
1151        V = ConstantExpr::get(Opc, LHS, RHS, Flags);
1152      }
1153      break;
1154    }
1155    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
1156      if (Record.size() < 3) return Error("Invalid CE_CAST record");
1157      int Opc = GetDecodedCastOpcode(Record[0]);
1158      if (Opc < 0) {
1159        V = UndefValue::get(CurTy);  // Unknown cast.
1160      } else {
1161        Type *OpTy = getTypeByID(Record[1]);
1162        if (!OpTy) return Error("Invalid CE_CAST record");
1163        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
1164        V = ConstantExpr::getCast(Opc, Op, CurTy);
1165      }
1166      break;
1167    }
1168    case bitc::CST_CODE_CE_INBOUNDS_GEP:
1169    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
1170      if (Record.size() & 1) return Error("Invalid CE_GEP record");
1171      SmallVector<Constant*, 16> Elts;
1172      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
1173        Type *ElTy = getTypeByID(Record[i]);
1174        if (!ElTy) return Error("Invalid CE_GEP record");
1175        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
1176      }
1177      ArrayRef<Constant *> Indices(Elts.begin() + 1, Elts.end());
1178      V = ConstantExpr::getGetElementPtr(Elts[0], Indices,
1179                                         BitCode ==
1180                                           bitc::CST_CODE_CE_INBOUNDS_GEP);
1181      break;
1182    }
1183    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
1184      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
1185      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
1186                                                              Type::getInt1Ty(Context)),
1187                                  ValueList.getConstantFwdRef(Record[1],CurTy),
1188                                  ValueList.getConstantFwdRef(Record[2],CurTy));
1189      break;
1190    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
1191      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
1192      VectorType *OpTy =
1193        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1194      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
1195      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1196      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
1197      V = ConstantExpr::getExtractElement(Op0, Op1);
1198      break;
1199    }
1200    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
1201      VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1202      if (Record.size() < 3 || OpTy == 0)
1203        return Error("Invalid CE_INSERTELT record");
1204      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1205      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
1206                                                  OpTy->getElementType());
1207      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
1208      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
1209      break;
1210    }
1211    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
1212      VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1213      if (Record.size() < 3 || OpTy == 0)
1214        return Error("Invalid CE_SHUFFLEVEC record");
1215      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1216      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
1217      Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
1218                                                 OpTy->getNumElements());
1219      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
1220      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1221      break;
1222    }
1223    case bitc::CST_CODE_CE_SHUFVEC_EX: { // [opty, opval, opval, opval]
1224      VectorType *RTy = dyn_cast<VectorType>(CurTy);
1225      VectorType *OpTy =
1226        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1227      if (Record.size() < 4 || RTy == 0 || OpTy == 0)
1228        return Error("Invalid CE_SHUFVEC_EX record");
1229      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1230      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1231      Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
1232                                                 RTy->getNumElements());
1233      Constant *Op2 = ValueList.getConstantFwdRef(Record[3], ShufTy);
1234      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1235      break;
1236    }
1237    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
1238      if (Record.size() < 4) return Error("Invalid CE_CMP record");
1239      Type *OpTy = getTypeByID(Record[0]);
1240      if (OpTy == 0) return Error("Invalid CE_CMP record");
1241      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1242      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1243
1244      if (OpTy->isFPOrFPVectorTy())
1245        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
1246      else
1247        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
1248      break;
1249    }
1250    // This maintains backward compatibility, pre-asm dialect keywords.
1251    // FIXME: Remove with the 4.0 release.
1252    case bitc::CST_CODE_INLINEASM_OLD: {
1253      if (Record.size() < 2) return Error("Invalid INLINEASM record");
1254      std::string AsmStr, ConstrStr;
1255      bool HasSideEffects = Record[0] & 1;
1256      bool IsAlignStack = Record[0] >> 1;
1257      unsigned AsmStrSize = Record[1];
1258      if (2+AsmStrSize >= Record.size())
1259        return Error("Invalid INLINEASM record");
1260      unsigned ConstStrSize = Record[2+AsmStrSize];
1261      if (3+AsmStrSize+ConstStrSize > Record.size())
1262        return Error("Invalid INLINEASM record");
1263
1264      for (unsigned i = 0; i != AsmStrSize; ++i)
1265        AsmStr += (char)Record[2+i];
1266      for (unsigned i = 0; i != ConstStrSize; ++i)
1267        ConstrStr += (char)Record[3+AsmStrSize+i];
1268      PointerType *PTy = cast<PointerType>(CurTy);
1269      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
1270                         AsmStr, ConstrStr, HasSideEffects, IsAlignStack);
1271      break;
1272    }
1273    // This version adds support for the asm dialect keywords (e.g.,
1274    // inteldialect).
1275    case bitc::CST_CODE_INLINEASM: {
1276      if (Record.size() < 2) return Error("Invalid INLINEASM record");
1277      std::string AsmStr, ConstrStr;
1278      bool HasSideEffects = Record[0] & 1;
1279      bool IsAlignStack = (Record[0] >> 1) & 1;
1280      unsigned AsmDialect = Record[0] >> 2;
1281      unsigned AsmStrSize = Record[1];
1282      if (2+AsmStrSize >= Record.size())
1283        return Error("Invalid INLINEASM record");
1284      unsigned ConstStrSize = Record[2+AsmStrSize];
1285      if (3+AsmStrSize+ConstStrSize > Record.size())
1286        return Error("Invalid INLINEASM record");
1287
1288      for (unsigned i = 0; i != AsmStrSize; ++i)
1289        AsmStr += (char)Record[2+i];
1290      for (unsigned i = 0; i != ConstStrSize; ++i)
1291        ConstrStr += (char)Record[3+AsmStrSize+i];
1292      PointerType *PTy = cast<PointerType>(CurTy);
1293      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
1294                         AsmStr, ConstrStr, HasSideEffects, IsAlignStack,
1295                         InlineAsm::AsmDialect(AsmDialect));
1296      break;
1297    }
1298    case bitc::CST_CODE_BLOCKADDRESS:{
1299      if (Record.size() < 3) return Error("Invalid CE_BLOCKADDRESS record");
1300      Type *FnTy = getTypeByID(Record[0]);
1301      if (FnTy == 0) return Error("Invalid CE_BLOCKADDRESS record");
1302      Function *Fn =
1303        dyn_cast_or_null<Function>(ValueList.getConstantFwdRef(Record[1],FnTy));
1304      if (Fn == 0) return Error("Invalid CE_BLOCKADDRESS record");
1305
1306      // If the function is already parsed we can insert the block address right
1307      // away.
1308      if (!Fn->empty()) {
1309        Function::iterator BBI = Fn->begin(), BBE = Fn->end();
1310        for (size_t I = 0, E = Record[2]; I != E; ++I) {
1311          if (BBI == BBE)
1312            return Error("Invalid blockaddress block #");
1313          ++BBI;
1314        }
1315        V = BlockAddress::get(Fn, BBI);
1316      } else {
1317        // Otherwise insert a placeholder and remember it so it can be inserted
1318        // when the function is parsed.
1319        GlobalVariable *FwdRef = new GlobalVariable(*Fn->getParent(),
1320                                                    Type::getInt8Ty(Context),
1321                                            false, GlobalValue::InternalLinkage,
1322                                                    0, "");
1323        BlockAddrFwdRefs[Fn].push_back(std::make_pair(Record[2], FwdRef));
1324        V = FwdRef;
1325      }
1326      break;
1327    }
1328    }
1329
1330    ValueList.AssignValue(V, NextCstNo);
1331    ++NextCstNo;
1332  }
1333
1334  if (NextCstNo != ValueList.size())
1335    return Error("Invalid constant reference!");
1336
1337  if (Stream.ReadBlockEnd())
1338    return Error("Error at end of constants block");
1339
1340  // Once all the constants have been read, go through and resolve forward
1341  // references.
1342  ValueList.ResolveConstantForwardRefs();
1343  return false;
1344}
1345
1346bool BitcodeReader::ParseUseLists() {
1347  if (Stream.EnterSubBlock(bitc::USELIST_BLOCK_ID))
1348    return Error("Malformed block record");
1349
1350  SmallVector<uint64_t, 64> Record;
1351
1352  // Read all the records.
1353  while (1) {
1354    unsigned Code = Stream.ReadCode();
1355    if (Code == bitc::END_BLOCK) {
1356      if (Stream.ReadBlockEnd())
1357        return Error("Error at end of use-list table block");
1358      return false;
1359    }
1360
1361    if (Code == bitc::ENTER_SUBBLOCK) {
1362      // No known subblocks, always skip them.
1363      Stream.ReadSubBlockID();
1364      if (Stream.SkipBlock())
1365        return Error("Malformed block record");
1366      continue;
1367    }
1368
1369    if (Code == bitc::DEFINE_ABBREV) {
1370      Stream.ReadAbbrevRecord();
1371      continue;
1372    }
1373
1374    // Read a use list record.
1375    Record.clear();
1376    switch (Stream.ReadRecord(Code, Record)) {
1377    default:  // Default behavior: unknown type.
1378      break;
1379    case bitc::USELIST_CODE_ENTRY: { // USELIST_CODE_ENTRY: TBD.
1380      unsigned RecordLength = Record.size();
1381      if (RecordLength < 1)
1382        return Error ("Invalid UseList reader!");
1383      UseListRecords.push_back(Record);
1384      break;
1385    }
1386    }
1387  }
1388}
1389
1390/// RememberAndSkipFunctionBody - When we see the block for a function body,
1391/// remember where it is and then skip it.  This lets us lazily deserialize the
1392/// functions.
1393bool BitcodeReader::RememberAndSkipFunctionBody() {
1394  // Get the function we are talking about.
1395  if (FunctionsWithBodies.empty())
1396    return Error("Insufficient function protos");
1397
1398  Function *Fn = FunctionsWithBodies.back();
1399  FunctionsWithBodies.pop_back();
1400
1401  // Save the current stream state.
1402  uint64_t CurBit = Stream.GetCurrentBitNo();
1403  DeferredFunctionInfo[Fn] = CurBit;
1404
1405  // Skip over the function block for now.
1406  if (Stream.SkipBlock())
1407    return Error("Malformed block record");
1408  return false;
1409}
1410
1411bool BitcodeReader::GlobalCleanup() {
1412  // Patch the initializers for globals and aliases up.
1413  ResolveGlobalAndAliasInits();
1414  if (!GlobalInits.empty() || !AliasInits.empty())
1415    return Error("Malformed global initializer set");
1416
1417  // Look for intrinsic functions which need to be upgraded at some point
1418  for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
1419       FI != FE; ++FI) {
1420    Function *NewFn;
1421    if (UpgradeIntrinsicFunction(FI, NewFn))
1422      UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
1423  }
1424
1425  // Look for global variables which need to be renamed.
1426  for (Module::global_iterator
1427         GI = TheModule->global_begin(), GE = TheModule->global_end();
1428       GI != GE; ++GI)
1429    UpgradeGlobalVariable(GI);
1430  // Force deallocation of memory for these vectors to favor the client that
1431  // want lazy deserialization.
1432  std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
1433  std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
1434  return false;
1435}
1436
1437bool BitcodeReader::ParseModule(bool Resume) {
1438  if (Resume)
1439    Stream.JumpToBit(NextUnreadBit);
1440  else if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
1441    return Error("Malformed block record");
1442
1443  SmallVector<uint64_t, 64> Record;
1444  std::vector<std::string> SectionTable;
1445  std::vector<std::string> GCTable;
1446
1447  // Read all the records for this module.
1448  while (!Stream.AtEndOfStream()) {
1449    unsigned Code = Stream.ReadCode();
1450    if (Code == bitc::END_BLOCK) {
1451      if (Stream.ReadBlockEnd())
1452        return Error("Error at end of module block");
1453
1454      return GlobalCleanup();
1455    }
1456
1457    if (Code == bitc::ENTER_SUBBLOCK) {
1458      switch (Stream.ReadSubBlockID()) {
1459      default:  // Skip unknown content.
1460        if (Stream.SkipBlock())
1461          return Error("Malformed block record");
1462        break;
1463      case bitc::BLOCKINFO_BLOCK_ID:
1464        if (Stream.ReadBlockInfoBlock())
1465          return Error("Malformed BlockInfoBlock");
1466        break;
1467      case bitc::PARAMATTR_BLOCK_ID:
1468        if (ParseAttributeBlock())
1469          return true;
1470        break;
1471      case bitc::TYPE_BLOCK_ID_NEW:
1472        if (ParseTypeTable())
1473          return true;
1474        break;
1475      case bitc::VALUE_SYMTAB_BLOCK_ID:
1476        if (ParseValueSymbolTable())
1477          return true;
1478        SeenValueSymbolTable = true;
1479        break;
1480      case bitc::CONSTANTS_BLOCK_ID:
1481        if (ParseConstants() || ResolveGlobalAndAliasInits())
1482          return true;
1483        break;
1484      case bitc::METADATA_BLOCK_ID:
1485        if (ParseMetadata())
1486          return true;
1487        break;
1488      case bitc::FUNCTION_BLOCK_ID:
1489        // If this is the first function body we've seen, reverse the
1490        // FunctionsWithBodies list.
1491        if (!SeenFirstFunctionBody) {
1492          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
1493          if (GlobalCleanup())
1494            return true;
1495          SeenFirstFunctionBody = true;
1496        }
1497
1498        if (RememberAndSkipFunctionBody())
1499          return true;
1500        // For streaming bitcode, suspend parsing when we reach the function
1501        // bodies. Subsequent materialization calls will resume it when
1502        // necessary. For streaming, the function bodies must be at the end of
1503        // the bitcode. If the bitcode file is old, the symbol table will be
1504        // at the end instead and will not have been seen yet. In this case,
1505        // just finish the parse now.
1506        if (LazyStreamer && SeenValueSymbolTable) {
1507          NextUnreadBit = Stream.GetCurrentBitNo();
1508          return false;
1509        }
1510        break;
1511      case bitc::USELIST_BLOCK_ID:
1512        if (ParseUseLists())
1513          return true;
1514        break;
1515      }
1516      continue;
1517    }
1518
1519    if (Code == bitc::DEFINE_ABBREV) {
1520      Stream.ReadAbbrevRecord();
1521      continue;
1522    }
1523
1524    // Read a record.
1525    switch (Stream.ReadRecord(Code, Record)) {
1526    default: break;  // Default behavior, ignore unknown content.
1527    case bitc::MODULE_CODE_VERSION: {  // VERSION: [version#]
1528      if (Record.size() < 1)
1529        return Error("Malformed MODULE_CODE_VERSION");
1530      // Only version #0 and #1 are supported so far.
1531      unsigned module_version = Record[0];
1532      switch (module_version) {
1533        default: return Error("Unknown bitstream version!");
1534        case 0:
1535          UseRelativeIDs = false;
1536          break;
1537        case 1:
1538          UseRelativeIDs = true;
1539          break;
1540      }
1541      break;
1542    }
1543    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1544      std::string S;
1545      if (ConvertToString(Record, 0, S))
1546        return Error("Invalid MODULE_CODE_TRIPLE record");
1547      TheModule->setTargetTriple(S);
1548      break;
1549    }
1550    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
1551      std::string S;
1552      if (ConvertToString(Record, 0, S))
1553        return Error("Invalid MODULE_CODE_DATALAYOUT record");
1554      TheModule->setDataLayout(S);
1555      break;
1556    }
1557    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
1558      std::string S;
1559      if (ConvertToString(Record, 0, S))
1560        return Error("Invalid MODULE_CODE_ASM record");
1561      TheModule->setModuleInlineAsm(S);
1562      break;
1563    }
1564    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
1565      std::string S;
1566      if (ConvertToString(Record, 0, S))
1567        return Error("Invalid MODULE_CODE_DEPLIB record");
1568      TheModule->addLibrary(S);
1569      break;
1570    }
1571    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
1572      std::string S;
1573      if (ConvertToString(Record, 0, S))
1574        return Error("Invalid MODULE_CODE_SECTIONNAME record");
1575      SectionTable.push_back(S);
1576      break;
1577    }
1578    case bitc::MODULE_CODE_GCNAME: {  // SECTIONNAME: [strchr x N]
1579      std::string S;
1580      if (ConvertToString(Record, 0, S))
1581        return Error("Invalid MODULE_CODE_GCNAME record");
1582      GCTable.push_back(S);
1583      break;
1584    }
1585    // GLOBALVAR: [pointer type, isconst, initid,
1586    //             linkage, alignment, section, visibility, threadlocal,
1587    //             unnamed_addr]
1588    case bitc::MODULE_CODE_GLOBALVAR: {
1589      if (Record.size() < 6)
1590        return Error("Invalid MODULE_CODE_GLOBALVAR record");
1591      Type *Ty = getTypeByID(Record[0]);
1592      if (!Ty) return Error("Invalid MODULE_CODE_GLOBALVAR record");
1593      if (!Ty->isPointerTy())
1594        return Error("Global not a pointer type!");
1595      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
1596      Ty = cast<PointerType>(Ty)->getElementType();
1597
1598      bool isConstant = Record[1];
1599      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1600      unsigned Alignment = (1 << Record[4]) >> 1;
1601      std::string Section;
1602      if (Record[5]) {
1603        if (Record[5]-1 >= SectionTable.size())
1604          return Error("Invalid section ID");
1605        Section = SectionTable[Record[5]-1];
1606      }
1607      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1608      if (Record.size() > 6)
1609        Visibility = GetDecodedVisibility(Record[6]);
1610
1611      GlobalVariable::ThreadLocalMode TLM = GlobalVariable::NotThreadLocal;
1612      if (Record.size() > 7)
1613        TLM = GetDecodedThreadLocalMode(Record[7]);
1614
1615      bool UnnamedAddr = false;
1616      if (Record.size() > 8)
1617        UnnamedAddr = Record[8];
1618
1619      GlobalVariable *NewGV =
1620        new GlobalVariable(*TheModule, Ty, isConstant, Linkage, 0, "", 0,
1621                           TLM, AddressSpace);
1622      NewGV->setAlignment(Alignment);
1623      if (!Section.empty())
1624        NewGV->setSection(Section);
1625      NewGV->setVisibility(Visibility);
1626      NewGV->setUnnamedAddr(UnnamedAddr);
1627
1628      ValueList.push_back(NewGV);
1629
1630      // Remember which value to use for the global initializer.
1631      if (unsigned InitID = Record[2])
1632        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1633      break;
1634    }
1635    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1636    //             alignment, section, visibility, gc, unnamed_addr]
1637    case bitc::MODULE_CODE_FUNCTION: {
1638      if (Record.size() < 8)
1639        return Error("Invalid MODULE_CODE_FUNCTION record");
1640      Type *Ty = getTypeByID(Record[0]);
1641      if (!Ty) return Error("Invalid MODULE_CODE_FUNCTION record");
1642      if (!Ty->isPointerTy())
1643        return Error("Function not a pointer type!");
1644      FunctionType *FTy =
1645        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1646      if (!FTy)
1647        return Error("Function not a pointer to function type!");
1648
1649      Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
1650                                        "", TheModule);
1651
1652      Func->setCallingConv(static_cast<CallingConv::ID>(Record[1]));
1653      bool isProto = Record[2];
1654      Func->setLinkage(GetDecodedLinkage(Record[3]));
1655      Func->setAttributes(getAttributes(Record[4]));
1656
1657      Func->setAlignment((1 << Record[5]) >> 1);
1658      if (Record[6]) {
1659        if (Record[6]-1 >= SectionTable.size())
1660          return Error("Invalid section ID");
1661        Func->setSection(SectionTable[Record[6]-1]);
1662      }
1663      Func->setVisibility(GetDecodedVisibility(Record[7]));
1664      if (Record.size() > 8 && Record[8]) {
1665        if (Record[8]-1 > GCTable.size())
1666          return Error("Invalid GC ID");
1667        Func->setGC(GCTable[Record[8]-1].c_str());
1668      }
1669      bool UnnamedAddr = false;
1670      if (Record.size() > 9)
1671        UnnamedAddr = Record[9];
1672      Func->setUnnamedAddr(UnnamedAddr);
1673      ValueList.push_back(Func);
1674
1675      // If this is a function with a body, remember the prototype we are
1676      // creating now, so that we can match up the body with them later.
1677      if (!isProto) {
1678        FunctionsWithBodies.push_back(Func);
1679        if (LazyStreamer) DeferredFunctionInfo[Func] = 0;
1680      }
1681      break;
1682    }
1683    // ALIAS: [alias type, aliasee val#, linkage]
1684    // ALIAS: [alias type, aliasee val#, linkage, visibility]
1685    case bitc::MODULE_CODE_ALIAS: {
1686      if (Record.size() < 3)
1687        return Error("Invalid MODULE_ALIAS record");
1688      Type *Ty = getTypeByID(Record[0]);
1689      if (!Ty) return Error("Invalid MODULE_ALIAS record");
1690      if (!Ty->isPointerTy())
1691        return Error("Function not a pointer type!");
1692
1693      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1694                                           "", 0, TheModule);
1695      // Old bitcode files didn't have visibility field.
1696      if (Record.size() > 3)
1697        NewGA->setVisibility(GetDecodedVisibility(Record[3]));
1698      ValueList.push_back(NewGA);
1699      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1700      break;
1701    }
1702    /// MODULE_CODE_PURGEVALS: [numvals]
1703    case bitc::MODULE_CODE_PURGEVALS:
1704      // Trim down the value list to the specified size.
1705      if (Record.size() < 1 || Record[0] > ValueList.size())
1706        return Error("Invalid MODULE_PURGEVALS record");
1707      ValueList.shrinkTo(Record[0]);
1708      break;
1709    }
1710    Record.clear();
1711  }
1712
1713  return Error("Premature end of bitstream");
1714}
1715
1716bool BitcodeReader::ParseBitcodeInto(Module *M) {
1717  TheModule = 0;
1718
1719  if (InitStream()) return true;
1720
1721  // Sniff for the signature.
1722  if (Stream.Read(8) != 'B' ||
1723      Stream.Read(8) != 'C' ||
1724      Stream.Read(4) != 0x0 ||
1725      Stream.Read(4) != 0xC ||
1726      Stream.Read(4) != 0xE ||
1727      Stream.Read(4) != 0xD)
1728    return Error("Invalid bitcode signature");
1729
1730  // We expect a number of well-defined blocks, though we don't necessarily
1731  // need to understand them all.
1732  while (!Stream.AtEndOfStream()) {
1733    unsigned Code = Stream.ReadCode();
1734
1735    if (Code != bitc::ENTER_SUBBLOCK) {
1736
1737      // The ranlib in xcode 4 will align archive members by appending newlines
1738      // to the end of them. If this file size is a multiple of 4 but not 8, we
1739      // have to read and ignore these final 4 bytes :-(
1740      if (Stream.GetAbbrevIDWidth() == 2 && Code == 2 &&
1741          Stream.Read(6) == 2 && Stream.Read(24) == 0xa0a0a &&
1742          Stream.AtEndOfStream())
1743        return false;
1744
1745      return Error("Invalid record at top-level");
1746    }
1747
1748    unsigned BlockID = Stream.ReadSubBlockID();
1749
1750    // We only know the MODULE subblock ID.
1751    switch (BlockID) {
1752    case bitc::BLOCKINFO_BLOCK_ID:
1753      if (Stream.ReadBlockInfoBlock())
1754        return Error("Malformed BlockInfoBlock");
1755      break;
1756    case bitc::MODULE_BLOCK_ID:
1757      // Reject multiple MODULE_BLOCK's in a single bitstream.
1758      if (TheModule)
1759        return Error("Multiple MODULE_BLOCKs in same stream");
1760      TheModule = M;
1761      if (ParseModule(false))
1762        return true;
1763      if (LazyStreamer) return false;
1764      break;
1765    default:
1766      if (Stream.SkipBlock())
1767        return Error("Malformed block record");
1768      break;
1769    }
1770  }
1771
1772  return false;
1773}
1774
1775bool BitcodeReader::ParseModuleTriple(std::string &Triple) {
1776  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
1777    return Error("Malformed block record");
1778
1779  SmallVector<uint64_t, 64> Record;
1780
1781  // Read all the records for this module.
1782  while (!Stream.AtEndOfStream()) {
1783    unsigned Code = Stream.ReadCode();
1784    if (Code == bitc::END_BLOCK) {
1785      if (Stream.ReadBlockEnd())
1786        return Error("Error at end of module block");
1787
1788      return false;
1789    }
1790
1791    if (Code == bitc::ENTER_SUBBLOCK) {
1792      switch (Stream.ReadSubBlockID()) {
1793      default:  // Skip unknown content.
1794        if (Stream.SkipBlock())
1795          return Error("Malformed block record");
1796        break;
1797      }
1798      continue;
1799    }
1800
1801    if (Code == bitc::DEFINE_ABBREV) {
1802      Stream.ReadAbbrevRecord();
1803      continue;
1804    }
1805
1806    // Read a record.
1807    switch (Stream.ReadRecord(Code, Record)) {
1808    default: break;  // Default behavior, ignore unknown content.
1809    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1810      std::string S;
1811      if (ConvertToString(Record, 0, S))
1812        return Error("Invalid MODULE_CODE_TRIPLE record");
1813      Triple = S;
1814      break;
1815    }
1816    }
1817    Record.clear();
1818  }
1819
1820  return Error("Premature end of bitstream");
1821}
1822
1823bool BitcodeReader::ParseTriple(std::string &Triple) {
1824  if (InitStream()) return true;
1825
1826  // Sniff for the signature.
1827  if (Stream.Read(8) != 'B' ||
1828      Stream.Read(8) != 'C' ||
1829      Stream.Read(4) != 0x0 ||
1830      Stream.Read(4) != 0xC ||
1831      Stream.Read(4) != 0xE ||
1832      Stream.Read(4) != 0xD)
1833    return Error("Invalid bitcode signature");
1834
1835  // We expect a number of well-defined blocks, though we don't necessarily
1836  // need to understand them all.
1837  while (!Stream.AtEndOfStream()) {
1838    unsigned Code = Stream.ReadCode();
1839
1840    if (Code != bitc::ENTER_SUBBLOCK)
1841      return Error("Invalid record at top-level");
1842
1843    unsigned BlockID = Stream.ReadSubBlockID();
1844
1845    // We only know the MODULE subblock ID.
1846    switch (BlockID) {
1847    case bitc::MODULE_BLOCK_ID:
1848      if (ParseModuleTriple(Triple))
1849        return true;
1850      break;
1851    default:
1852      if (Stream.SkipBlock())
1853        return Error("Malformed block record");
1854      break;
1855    }
1856  }
1857
1858  return false;
1859}
1860
1861/// ParseMetadataAttachment - Parse metadata attachments.
1862bool BitcodeReader::ParseMetadataAttachment() {
1863  if (Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
1864    return Error("Malformed block record");
1865
1866  SmallVector<uint64_t, 64> Record;
1867  while(1) {
1868    unsigned Code = Stream.ReadCode();
1869    if (Code == bitc::END_BLOCK) {
1870      if (Stream.ReadBlockEnd())
1871        return Error("Error at end of PARAMATTR block");
1872      break;
1873    }
1874    if (Code == bitc::DEFINE_ABBREV) {
1875      Stream.ReadAbbrevRecord();
1876      continue;
1877    }
1878    // Read a metadata attachment record.
1879    Record.clear();
1880    switch (Stream.ReadRecord(Code, Record)) {
1881    default:  // Default behavior: ignore.
1882      break;
1883    case bitc::METADATA_ATTACHMENT: {
1884      unsigned RecordLength = Record.size();
1885      if (Record.empty() || (RecordLength - 1) % 2 == 1)
1886        return Error ("Invalid METADATA_ATTACHMENT reader!");
1887      Instruction *Inst = InstructionList[Record[0]];
1888      for (unsigned i = 1; i != RecordLength; i = i+2) {
1889        unsigned Kind = Record[i];
1890        DenseMap<unsigned, unsigned>::iterator I =
1891          MDKindMap.find(Kind);
1892        if (I == MDKindMap.end())
1893          return Error("Invalid metadata kind ID");
1894        Value *Node = MDValueList.getValueFwdRef(Record[i+1]);
1895        Inst->setMetadata(I->second, cast<MDNode>(Node));
1896      }
1897      break;
1898    }
1899    }
1900  }
1901  return false;
1902}
1903
1904/// ParseFunctionBody - Lazily parse the specified function body block.
1905bool BitcodeReader::ParseFunctionBody(Function *F) {
1906  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1907    return Error("Malformed block record");
1908
1909  InstructionList.clear();
1910  unsigned ModuleValueListSize = ValueList.size();
1911  unsigned ModuleMDValueListSize = MDValueList.size();
1912
1913  // Add all the function arguments to the value table.
1914  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1915    ValueList.push_back(I);
1916
1917  unsigned NextValueNo = ValueList.size();
1918  BasicBlock *CurBB = 0;
1919  unsigned CurBBNo = 0;
1920
1921  DebugLoc LastLoc;
1922
1923  // Read all the records.
1924  SmallVector<uint64_t, 64> Record;
1925  while (1) {
1926    unsigned Code = Stream.ReadCode();
1927    if (Code == bitc::END_BLOCK) {
1928      if (Stream.ReadBlockEnd())
1929        return Error("Error at end of function block");
1930      break;
1931    }
1932
1933    if (Code == bitc::ENTER_SUBBLOCK) {
1934      switch (Stream.ReadSubBlockID()) {
1935      default:  // Skip unknown content.
1936        if (Stream.SkipBlock())
1937          return Error("Malformed block record");
1938        break;
1939      case bitc::CONSTANTS_BLOCK_ID:
1940        if (ParseConstants()) return true;
1941        NextValueNo = ValueList.size();
1942        break;
1943      case bitc::VALUE_SYMTAB_BLOCK_ID:
1944        if (ParseValueSymbolTable()) return true;
1945        break;
1946      case bitc::METADATA_ATTACHMENT_ID:
1947        if (ParseMetadataAttachment()) return true;
1948        break;
1949      case bitc::METADATA_BLOCK_ID:
1950        if (ParseMetadata()) return true;
1951        break;
1952      }
1953      continue;
1954    }
1955
1956    if (Code == bitc::DEFINE_ABBREV) {
1957      Stream.ReadAbbrevRecord();
1958      continue;
1959    }
1960
1961    // Read a record.
1962    Record.clear();
1963    Instruction *I = 0;
1964    unsigned BitCode = Stream.ReadRecord(Code, Record);
1965    switch (BitCode) {
1966    default: // Default behavior: reject
1967      return Error("Unknown instruction");
1968    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1969      if (Record.size() < 1 || Record[0] == 0)
1970        return Error("Invalid DECLAREBLOCKS record");
1971      // Create all the basic blocks for the function.
1972      FunctionBBs.resize(Record[0]);
1973      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1974        FunctionBBs[i] = BasicBlock::Create(Context, "", F);
1975      CurBB = FunctionBBs[0];
1976      continue;
1977
1978    case bitc::FUNC_CODE_DEBUG_LOC_AGAIN:  // DEBUG_LOC_AGAIN
1979      // This record indicates that the last instruction is at the same
1980      // location as the previous instruction with a location.
1981      I = 0;
1982
1983      // Get the last instruction emitted.
1984      if (CurBB && !CurBB->empty())
1985        I = &CurBB->back();
1986      else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
1987               !FunctionBBs[CurBBNo-1]->empty())
1988        I = &FunctionBBs[CurBBNo-1]->back();
1989
1990      if (I == 0) return Error("Invalid DEBUG_LOC_AGAIN record");
1991      I->setDebugLoc(LastLoc);
1992      I = 0;
1993      continue;
1994
1995    case bitc::FUNC_CODE_DEBUG_LOC: {      // DEBUG_LOC: [line, col, scope, ia]
1996      I = 0;     // Get the last instruction emitted.
1997      if (CurBB && !CurBB->empty())
1998        I = &CurBB->back();
1999      else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
2000               !FunctionBBs[CurBBNo-1]->empty())
2001        I = &FunctionBBs[CurBBNo-1]->back();
2002      if (I == 0 || Record.size() < 4)
2003        return Error("Invalid FUNC_CODE_DEBUG_LOC record");
2004
2005      unsigned Line = Record[0], Col = Record[1];
2006      unsigned ScopeID = Record[2], IAID = Record[3];
2007
2008      MDNode *Scope = 0, *IA = 0;
2009      if (ScopeID) Scope = cast<MDNode>(MDValueList.getValueFwdRef(ScopeID-1));
2010      if (IAID)    IA = cast<MDNode>(MDValueList.getValueFwdRef(IAID-1));
2011      LastLoc = DebugLoc::get(Line, Col, Scope, IA);
2012      I->setDebugLoc(LastLoc);
2013      I = 0;
2014      continue;
2015    }
2016
2017    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
2018      unsigned OpNum = 0;
2019      Value *LHS, *RHS;
2020      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
2021          popValue(Record, OpNum, NextValueNo, LHS->getType(), RHS) ||
2022          OpNum+1 > Record.size())
2023        return Error("Invalid BINOP record");
2024
2025      int Opc = GetDecodedBinaryOpcode(Record[OpNum++], LHS->getType());
2026      if (Opc == -1) return Error("Invalid BINOP record");
2027      I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
2028      InstructionList.push_back(I);
2029      if (OpNum < Record.size()) {
2030        if (Opc == Instruction::Add ||
2031            Opc == Instruction::Sub ||
2032            Opc == Instruction::Mul ||
2033            Opc == Instruction::Shl) {
2034          if (Record[OpNum] & (1 << bitc::OBO_NO_SIGNED_WRAP))
2035            cast<BinaryOperator>(I)->setHasNoSignedWrap(true);
2036          if (Record[OpNum] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
2037            cast<BinaryOperator>(I)->setHasNoUnsignedWrap(true);
2038        } else if (Opc == Instruction::SDiv ||
2039                   Opc == Instruction::UDiv ||
2040                   Opc == Instruction::LShr ||
2041                   Opc == Instruction::AShr) {
2042          if (Record[OpNum] & (1 << bitc::PEO_EXACT))
2043            cast<BinaryOperator>(I)->setIsExact(true);
2044        }
2045      }
2046      break;
2047    }
2048    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
2049      unsigned OpNum = 0;
2050      Value *Op;
2051      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2052          OpNum+2 != Record.size())
2053        return Error("Invalid CAST record");
2054
2055      Type *ResTy = getTypeByID(Record[OpNum]);
2056      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
2057      if (Opc == -1 || ResTy == 0)
2058        return Error("Invalid CAST record");
2059      I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
2060      InstructionList.push_back(I);
2061      break;
2062    }
2063    case bitc::FUNC_CODE_INST_INBOUNDS_GEP:
2064    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
2065      unsigned OpNum = 0;
2066      Value *BasePtr;
2067      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
2068        return Error("Invalid GEP record");
2069
2070      SmallVector<Value*, 16> GEPIdx;
2071      while (OpNum != Record.size()) {
2072        Value *Op;
2073        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2074          return Error("Invalid GEP record");
2075        GEPIdx.push_back(Op);
2076      }
2077
2078      I = GetElementPtrInst::Create(BasePtr, GEPIdx);
2079      InstructionList.push_back(I);
2080      if (BitCode == bitc::FUNC_CODE_INST_INBOUNDS_GEP)
2081        cast<GetElementPtrInst>(I)->setIsInBounds(true);
2082      break;
2083    }
2084
2085    case bitc::FUNC_CODE_INST_EXTRACTVAL: {
2086                                       // EXTRACTVAL: [opty, opval, n x indices]
2087      unsigned OpNum = 0;
2088      Value *Agg;
2089      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2090        return Error("Invalid EXTRACTVAL record");
2091
2092      SmallVector<unsigned, 4> EXTRACTVALIdx;
2093      for (unsigned RecSize = Record.size();
2094           OpNum != RecSize; ++OpNum) {
2095        uint64_t Index = Record[OpNum];
2096        if ((unsigned)Index != Index)
2097          return Error("Invalid EXTRACTVAL index");
2098        EXTRACTVALIdx.push_back((unsigned)Index);
2099      }
2100
2101      I = ExtractValueInst::Create(Agg, EXTRACTVALIdx);
2102      InstructionList.push_back(I);
2103      break;
2104    }
2105
2106    case bitc::FUNC_CODE_INST_INSERTVAL: {
2107                           // INSERTVAL: [opty, opval, opty, opval, n x indices]
2108      unsigned OpNum = 0;
2109      Value *Agg;
2110      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2111        return Error("Invalid INSERTVAL record");
2112      Value *Val;
2113      if (getValueTypePair(Record, OpNum, NextValueNo, Val))
2114        return Error("Invalid INSERTVAL record");
2115
2116      SmallVector<unsigned, 4> INSERTVALIdx;
2117      for (unsigned RecSize = Record.size();
2118           OpNum != RecSize; ++OpNum) {
2119        uint64_t Index = Record[OpNum];
2120        if ((unsigned)Index != Index)
2121          return Error("Invalid INSERTVAL index");
2122        INSERTVALIdx.push_back((unsigned)Index);
2123      }
2124
2125      I = InsertValueInst::Create(Agg, Val, INSERTVALIdx);
2126      InstructionList.push_back(I);
2127      break;
2128    }
2129
2130    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
2131      // obsolete form of select
2132      // handles select i1 ... in old bitcode
2133      unsigned OpNum = 0;
2134      Value *TrueVal, *FalseVal, *Cond;
2135      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2136          popValue(Record, OpNum, NextValueNo, TrueVal->getType(), FalseVal) ||
2137          popValue(Record, OpNum, NextValueNo, Type::getInt1Ty(Context), Cond))
2138        return Error("Invalid SELECT record");
2139
2140      I = SelectInst::Create(Cond, TrueVal, FalseVal);
2141      InstructionList.push_back(I);
2142      break;
2143    }
2144
2145    case bitc::FUNC_CODE_INST_VSELECT: {// VSELECT: [ty,opval,opval,predty,pred]
2146      // new form of select
2147      // handles select i1 or select [N x i1]
2148      unsigned OpNum = 0;
2149      Value *TrueVal, *FalseVal, *Cond;
2150      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2151          popValue(Record, OpNum, NextValueNo, TrueVal->getType(), FalseVal) ||
2152          getValueTypePair(Record, OpNum, NextValueNo, Cond))
2153        return Error("Invalid SELECT record");
2154
2155      // select condition can be either i1 or [N x i1]
2156      if (VectorType* vector_type =
2157          dyn_cast<VectorType>(Cond->getType())) {
2158        // expect <n x i1>
2159        if (vector_type->getElementType() != Type::getInt1Ty(Context))
2160          return Error("Invalid SELECT condition type");
2161      } else {
2162        // expect i1
2163        if (Cond->getType() != Type::getInt1Ty(Context))
2164          return Error("Invalid SELECT condition type");
2165      }
2166
2167      I = SelectInst::Create(Cond, TrueVal, FalseVal);
2168      InstructionList.push_back(I);
2169      break;
2170    }
2171
2172    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
2173      unsigned OpNum = 0;
2174      Value *Vec, *Idx;
2175      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2176          popValue(Record, OpNum, NextValueNo, Type::getInt32Ty(Context), Idx))
2177        return Error("Invalid EXTRACTELT record");
2178      I = ExtractElementInst::Create(Vec, Idx);
2179      InstructionList.push_back(I);
2180      break;
2181    }
2182
2183    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
2184      unsigned OpNum = 0;
2185      Value *Vec, *Elt, *Idx;
2186      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2187          popValue(Record, OpNum, NextValueNo,
2188                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
2189          popValue(Record, OpNum, NextValueNo, Type::getInt32Ty(Context), Idx))
2190        return Error("Invalid INSERTELT record");
2191      I = InsertElementInst::Create(Vec, Elt, Idx);
2192      InstructionList.push_back(I);
2193      break;
2194    }
2195
2196    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
2197      unsigned OpNum = 0;
2198      Value *Vec1, *Vec2, *Mask;
2199      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
2200          popValue(Record, OpNum, NextValueNo, Vec1->getType(), Vec2))
2201        return Error("Invalid SHUFFLEVEC record");
2202
2203      if (getValueTypePair(Record, OpNum, NextValueNo, Mask))
2204        return Error("Invalid SHUFFLEVEC record");
2205      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
2206      InstructionList.push_back(I);
2207      break;
2208    }
2209
2210    case bitc::FUNC_CODE_INST_CMP:   // CMP: [opty, opval, opval, pred]
2211      // Old form of ICmp/FCmp returning bool
2212      // Existed to differentiate between icmp/fcmp and vicmp/vfcmp which were
2213      // both legal on vectors but had different behaviour.
2214    case bitc::FUNC_CODE_INST_CMP2: { // CMP2: [opty, opval, opval, pred]
2215      // FCmp/ICmp returning bool or vector of bool
2216
2217      unsigned OpNum = 0;
2218      Value *LHS, *RHS;
2219      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
2220          popValue(Record, OpNum, NextValueNo, LHS->getType(), RHS) ||
2221          OpNum+1 != Record.size())
2222        return Error("Invalid CMP record");
2223
2224      if (LHS->getType()->isFPOrFPVectorTy())
2225        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
2226      else
2227        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
2228      InstructionList.push_back(I);
2229      break;
2230    }
2231
2232    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
2233      {
2234        unsigned Size = Record.size();
2235        if (Size == 0) {
2236          I = ReturnInst::Create(Context);
2237          InstructionList.push_back(I);
2238          break;
2239        }
2240
2241        unsigned OpNum = 0;
2242        Value *Op = NULL;
2243        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2244          return Error("Invalid RET record");
2245        if (OpNum != Record.size())
2246          return Error("Invalid RET record");
2247
2248        I = ReturnInst::Create(Context, Op);
2249        InstructionList.push_back(I);
2250        break;
2251      }
2252    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
2253      if (Record.size() != 1 && Record.size() != 3)
2254        return Error("Invalid BR record");
2255      BasicBlock *TrueDest = getBasicBlock(Record[0]);
2256      if (TrueDest == 0)
2257        return Error("Invalid BR record");
2258
2259      if (Record.size() == 1) {
2260        I = BranchInst::Create(TrueDest);
2261        InstructionList.push_back(I);
2262      }
2263      else {
2264        BasicBlock *FalseDest = getBasicBlock(Record[1]);
2265        Value *Cond = getValue(Record, 2, NextValueNo,
2266                               Type::getInt1Ty(Context));
2267        if (FalseDest == 0 || Cond == 0)
2268          return Error("Invalid BR record");
2269        I = BranchInst::Create(TrueDest, FalseDest, Cond);
2270        InstructionList.push_back(I);
2271      }
2272      break;
2273    }
2274    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, op0, op1, ...]
2275      // Check magic
2276      if ((Record[0] >> 16) == SWITCH_INST_MAGIC) {
2277        // New SwitchInst format with case ranges.
2278
2279        Type *OpTy = getTypeByID(Record[1]);
2280        unsigned ValueBitWidth = cast<IntegerType>(OpTy)->getBitWidth();
2281
2282        Value *Cond = getValue(Record, 2, NextValueNo, OpTy);
2283        BasicBlock *Default = getBasicBlock(Record[3]);
2284        if (OpTy == 0 || Cond == 0 || Default == 0)
2285          return Error("Invalid SWITCH record");
2286
2287        unsigned NumCases = Record[4];
2288
2289        SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
2290        InstructionList.push_back(SI);
2291
2292        unsigned CurIdx = 5;
2293        for (unsigned i = 0; i != NumCases; ++i) {
2294          IntegersSubsetToBB CaseBuilder;
2295          unsigned NumItems = Record[CurIdx++];
2296          for (unsigned ci = 0; ci != NumItems; ++ci) {
2297            bool isSingleNumber = Record[CurIdx++];
2298
2299            APInt Low;
2300            unsigned ActiveWords = 1;
2301            if (ValueBitWidth > 64)
2302              ActiveWords = Record[CurIdx++];
2303            Low = ReadWideAPInt(makeArrayRef(&Record[CurIdx], ActiveWords),
2304                                ValueBitWidth);
2305            CurIdx += ActiveWords;
2306
2307            if (!isSingleNumber) {
2308              ActiveWords = 1;
2309              if (ValueBitWidth > 64)
2310                ActiveWords = Record[CurIdx++];
2311              APInt High =
2312                  ReadWideAPInt(makeArrayRef(&Record[CurIdx], ActiveWords),
2313                                ValueBitWidth);
2314
2315              CaseBuilder.add(IntItem::fromType(OpTy, Low),
2316                              IntItem::fromType(OpTy, High));
2317              CurIdx += ActiveWords;
2318            } else
2319              CaseBuilder.add(IntItem::fromType(OpTy, Low));
2320          }
2321          BasicBlock *DestBB = getBasicBlock(Record[CurIdx++]);
2322          IntegersSubset Case = CaseBuilder.getCase();
2323          SI->addCase(Case, DestBB);
2324        }
2325        uint16_t Hash = SI->hash();
2326        if (Hash != (Record[0] & 0xFFFF))
2327          return Error("Invalid SWITCH record");
2328        I = SI;
2329        break;
2330      }
2331
2332      // Old SwitchInst format without case ranges.
2333
2334      if (Record.size() < 3 || (Record.size() & 1) == 0)
2335        return Error("Invalid SWITCH record");
2336      Type *OpTy = getTypeByID(Record[0]);
2337      Value *Cond = getValue(Record, 1, NextValueNo, OpTy);
2338      BasicBlock *Default = getBasicBlock(Record[2]);
2339      if (OpTy == 0 || Cond == 0 || Default == 0)
2340        return Error("Invalid SWITCH record");
2341      unsigned NumCases = (Record.size()-3)/2;
2342      SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
2343      InstructionList.push_back(SI);
2344      for (unsigned i = 0, e = NumCases; i != e; ++i) {
2345        ConstantInt *CaseVal =
2346          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
2347        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
2348        if (CaseVal == 0 || DestBB == 0) {
2349          delete SI;
2350          return Error("Invalid SWITCH record!");
2351        }
2352        SI->addCase(CaseVal, DestBB);
2353      }
2354      I = SI;
2355      break;
2356    }
2357    case bitc::FUNC_CODE_INST_INDIRECTBR: { // INDIRECTBR: [opty, op0, op1, ...]
2358      if (Record.size() < 2)
2359        return Error("Invalid INDIRECTBR record");
2360      Type *OpTy = getTypeByID(Record[0]);
2361      Value *Address = getValue(Record, 1, NextValueNo, OpTy);
2362      if (OpTy == 0 || Address == 0)
2363        return Error("Invalid INDIRECTBR record");
2364      unsigned NumDests = Record.size()-2;
2365      IndirectBrInst *IBI = IndirectBrInst::Create(Address, NumDests);
2366      InstructionList.push_back(IBI);
2367      for (unsigned i = 0, e = NumDests; i != e; ++i) {
2368        if (BasicBlock *DestBB = getBasicBlock(Record[2+i])) {
2369          IBI->addDestination(DestBB);
2370        } else {
2371          delete IBI;
2372          return Error("Invalid INDIRECTBR record!");
2373        }
2374      }
2375      I = IBI;
2376      break;
2377    }
2378
2379    case bitc::FUNC_CODE_INST_INVOKE: {
2380      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
2381      if (Record.size() < 4) return Error("Invalid INVOKE record");
2382      AttrListPtr PAL = getAttributes(Record[0]);
2383      unsigned CCInfo = Record[1];
2384      BasicBlock *NormalBB = getBasicBlock(Record[2]);
2385      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
2386
2387      unsigned OpNum = 4;
2388      Value *Callee;
2389      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
2390        return Error("Invalid INVOKE record");
2391
2392      PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
2393      FunctionType *FTy = !CalleeTy ? 0 :
2394        dyn_cast<FunctionType>(CalleeTy->getElementType());
2395
2396      // Check that the right number of fixed parameters are here.
2397      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
2398          Record.size() < OpNum+FTy->getNumParams())
2399        return Error("Invalid INVOKE record");
2400
2401      SmallVector<Value*, 16> Ops;
2402      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
2403        Ops.push_back(getValue(Record, OpNum, NextValueNo,
2404                               FTy->getParamType(i)));
2405        if (Ops.back() == 0) return Error("Invalid INVOKE record");
2406      }
2407
2408      if (!FTy->isVarArg()) {
2409        if (Record.size() != OpNum)
2410          return Error("Invalid INVOKE record");
2411      } else {
2412        // Read type/value pairs for varargs params.
2413        while (OpNum != Record.size()) {
2414          Value *Op;
2415          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2416            return Error("Invalid INVOKE record");
2417          Ops.push_back(Op);
2418        }
2419      }
2420
2421      I = InvokeInst::Create(Callee, NormalBB, UnwindBB, Ops);
2422      InstructionList.push_back(I);
2423      cast<InvokeInst>(I)->setCallingConv(
2424        static_cast<CallingConv::ID>(CCInfo));
2425      cast<InvokeInst>(I)->setAttributes(PAL);
2426      break;
2427    }
2428    case bitc::FUNC_CODE_INST_RESUME: { // RESUME: [opval]
2429      unsigned Idx = 0;
2430      Value *Val = 0;
2431      if (getValueTypePair(Record, Idx, NextValueNo, Val))
2432        return Error("Invalid RESUME record");
2433      I = ResumeInst::Create(Val);
2434      InstructionList.push_back(I);
2435      break;
2436    }
2437    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
2438      I = new UnreachableInst(Context);
2439      InstructionList.push_back(I);
2440      break;
2441    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
2442      if (Record.size() < 1 || ((Record.size()-1)&1))
2443        return Error("Invalid PHI record");
2444      Type *Ty = getTypeByID(Record[0]);
2445      if (!Ty) return Error("Invalid PHI record");
2446
2447      PHINode *PN = PHINode::Create(Ty, (Record.size()-1)/2);
2448      InstructionList.push_back(PN);
2449
2450      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
2451        Value *V;
2452        // With the new function encoding, it is possible that operands have
2453        // negative IDs (for forward references).  Use a signed VBR
2454        // representation to keep the encoding small.
2455        if (UseRelativeIDs)
2456          V = getValueSigned(Record, 1+i, NextValueNo, Ty);
2457        else
2458          V = getValue(Record, 1+i, NextValueNo, Ty);
2459        BasicBlock *BB = getBasicBlock(Record[2+i]);
2460        if (!V || !BB) return Error("Invalid PHI record");
2461        PN->addIncoming(V, BB);
2462      }
2463      I = PN;
2464      break;
2465    }
2466
2467    case bitc::FUNC_CODE_INST_LANDINGPAD: {
2468      // LANDINGPAD: [ty, val, val, num, (id0,val0 ...)?]
2469      unsigned Idx = 0;
2470      if (Record.size() < 4)
2471        return Error("Invalid LANDINGPAD record");
2472      Type *Ty = getTypeByID(Record[Idx++]);
2473      if (!Ty) return Error("Invalid LANDINGPAD record");
2474      Value *PersFn = 0;
2475      if (getValueTypePair(Record, Idx, NextValueNo, PersFn))
2476        return Error("Invalid LANDINGPAD record");
2477
2478      bool IsCleanup = !!Record[Idx++];
2479      unsigned NumClauses = Record[Idx++];
2480      LandingPadInst *LP = LandingPadInst::Create(Ty, PersFn, NumClauses);
2481      LP->setCleanup(IsCleanup);
2482      for (unsigned J = 0; J != NumClauses; ++J) {
2483        LandingPadInst::ClauseType CT =
2484          LandingPadInst::ClauseType(Record[Idx++]); (void)CT;
2485        Value *Val;
2486
2487        if (getValueTypePair(Record, Idx, NextValueNo, Val)) {
2488          delete LP;
2489          return Error("Invalid LANDINGPAD record");
2490        }
2491
2492        assert((CT != LandingPadInst::Catch ||
2493                !isa<ArrayType>(Val->getType())) &&
2494               "Catch clause has a invalid type!");
2495        assert((CT != LandingPadInst::Filter ||
2496                isa<ArrayType>(Val->getType())) &&
2497               "Filter clause has invalid type!");
2498        LP->addClause(Val);
2499      }
2500
2501      I = LP;
2502      InstructionList.push_back(I);
2503      break;
2504    }
2505
2506    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, opty, op, align]
2507      if (Record.size() != 4)
2508        return Error("Invalid ALLOCA record");
2509      PointerType *Ty =
2510        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
2511      Type *OpTy = getTypeByID(Record[1]);
2512      Value *Size = getFnValueByID(Record[2], OpTy);
2513      unsigned Align = Record[3];
2514      if (!Ty || !Size) return Error("Invalid ALLOCA record");
2515      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
2516      InstructionList.push_back(I);
2517      break;
2518    }
2519    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
2520      unsigned OpNum = 0;
2521      Value *Op;
2522      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2523          OpNum+2 != Record.size())
2524        return Error("Invalid LOAD record");
2525
2526      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
2527      InstructionList.push_back(I);
2528      break;
2529    }
2530    case bitc::FUNC_CODE_INST_LOADATOMIC: {
2531       // LOADATOMIC: [opty, op, align, vol, ordering, synchscope]
2532      unsigned OpNum = 0;
2533      Value *Op;
2534      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2535          OpNum+4 != Record.size())
2536        return Error("Invalid LOADATOMIC record");
2537
2538
2539      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2540      if (Ordering == NotAtomic || Ordering == Release ||
2541          Ordering == AcquireRelease)
2542        return Error("Invalid LOADATOMIC record");
2543      if (Ordering != NotAtomic && Record[OpNum] == 0)
2544        return Error("Invalid LOADATOMIC record");
2545      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2546
2547      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1,
2548                       Ordering, SynchScope);
2549      InstructionList.push_back(I);
2550      break;
2551    }
2552    case bitc::FUNC_CODE_INST_STORE: { // STORE2:[ptrty, ptr, val, align, vol]
2553      unsigned OpNum = 0;
2554      Value *Val, *Ptr;
2555      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2556          popValue(Record, OpNum, NextValueNo,
2557                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2558          OpNum+2 != Record.size())
2559        return Error("Invalid STORE record");
2560
2561      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
2562      InstructionList.push_back(I);
2563      break;
2564    }
2565    case bitc::FUNC_CODE_INST_STOREATOMIC: {
2566      // STOREATOMIC: [ptrty, ptr, val, align, vol, ordering, synchscope]
2567      unsigned OpNum = 0;
2568      Value *Val, *Ptr;
2569      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2570          popValue(Record, OpNum, NextValueNo,
2571                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2572          OpNum+4 != Record.size())
2573        return Error("Invalid STOREATOMIC record");
2574
2575      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2576      if (Ordering == NotAtomic || Ordering == Acquire ||
2577          Ordering == AcquireRelease)
2578        return Error("Invalid STOREATOMIC record");
2579      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2580      if (Ordering != NotAtomic && Record[OpNum] == 0)
2581        return Error("Invalid STOREATOMIC record");
2582
2583      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1,
2584                        Ordering, SynchScope);
2585      InstructionList.push_back(I);
2586      break;
2587    }
2588    case bitc::FUNC_CODE_INST_CMPXCHG: {
2589      // CMPXCHG:[ptrty, ptr, cmp, new, vol, ordering, synchscope]
2590      unsigned OpNum = 0;
2591      Value *Ptr, *Cmp, *New;
2592      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2593          popValue(Record, OpNum, NextValueNo,
2594                    cast<PointerType>(Ptr->getType())->getElementType(), Cmp) ||
2595          popValue(Record, OpNum, NextValueNo,
2596                    cast<PointerType>(Ptr->getType())->getElementType(), New) ||
2597          OpNum+3 != Record.size())
2598        return Error("Invalid CMPXCHG record");
2599      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+1]);
2600      if (Ordering == NotAtomic || Ordering == Unordered)
2601        return Error("Invalid CMPXCHG record");
2602      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+2]);
2603      I = new AtomicCmpXchgInst(Ptr, Cmp, New, Ordering, SynchScope);
2604      cast<AtomicCmpXchgInst>(I)->setVolatile(Record[OpNum]);
2605      InstructionList.push_back(I);
2606      break;
2607    }
2608    case bitc::FUNC_CODE_INST_ATOMICRMW: {
2609      // ATOMICRMW:[ptrty, ptr, val, op, vol, ordering, synchscope]
2610      unsigned OpNum = 0;
2611      Value *Ptr, *Val;
2612      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2613          popValue(Record, OpNum, NextValueNo,
2614                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2615          OpNum+4 != Record.size())
2616        return Error("Invalid ATOMICRMW record");
2617      AtomicRMWInst::BinOp Operation = GetDecodedRMWOperation(Record[OpNum]);
2618      if (Operation < AtomicRMWInst::FIRST_BINOP ||
2619          Operation > AtomicRMWInst::LAST_BINOP)
2620        return Error("Invalid ATOMICRMW record");
2621      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2622      if (Ordering == NotAtomic || Ordering == Unordered)
2623        return Error("Invalid ATOMICRMW record");
2624      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2625      I = new AtomicRMWInst(Operation, Ptr, Val, Ordering, SynchScope);
2626      cast<AtomicRMWInst>(I)->setVolatile(Record[OpNum+1]);
2627      InstructionList.push_back(I);
2628      break;
2629    }
2630    case bitc::FUNC_CODE_INST_FENCE: { // FENCE:[ordering, synchscope]
2631      if (2 != Record.size())
2632        return Error("Invalid FENCE record");
2633      AtomicOrdering Ordering = GetDecodedOrdering(Record[0]);
2634      if (Ordering == NotAtomic || Ordering == Unordered ||
2635          Ordering == Monotonic)
2636        return Error("Invalid FENCE record");
2637      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[1]);
2638      I = new FenceInst(Context, Ordering, SynchScope);
2639      InstructionList.push_back(I);
2640      break;
2641    }
2642    case bitc::FUNC_CODE_INST_CALL: {
2643      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
2644      if (Record.size() < 3)
2645        return Error("Invalid CALL record");
2646
2647      AttrListPtr PAL = getAttributes(Record[0]);
2648      unsigned CCInfo = Record[1];
2649
2650      unsigned OpNum = 2;
2651      Value *Callee;
2652      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
2653        return Error("Invalid CALL record");
2654
2655      PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
2656      FunctionType *FTy = 0;
2657      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
2658      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
2659        return Error("Invalid CALL record");
2660
2661      SmallVector<Value*, 16> Args;
2662      // Read the fixed params.
2663      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
2664        if (FTy->getParamType(i)->isLabelTy())
2665          Args.push_back(getBasicBlock(Record[OpNum]));
2666        else
2667          Args.push_back(getValue(Record, OpNum, NextValueNo,
2668                                  FTy->getParamType(i)));
2669        if (Args.back() == 0) return Error("Invalid CALL record");
2670      }
2671
2672      // Read type/value pairs for varargs params.
2673      if (!FTy->isVarArg()) {
2674        if (OpNum != Record.size())
2675          return Error("Invalid CALL record");
2676      } else {
2677        while (OpNum != Record.size()) {
2678          Value *Op;
2679          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2680            return Error("Invalid CALL record");
2681          Args.push_back(Op);
2682        }
2683      }
2684
2685      I = CallInst::Create(Callee, Args);
2686      InstructionList.push_back(I);
2687      cast<CallInst>(I)->setCallingConv(
2688        static_cast<CallingConv::ID>(CCInfo>>1));
2689      cast<CallInst>(I)->setTailCall(CCInfo & 1);
2690      cast<CallInst>(I)->setAttributes(PAL);
2691      break;
2692    }
2693    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
2694      if (Record.size() < 3)
2695        return Error("Invalid VAARG record");
2696      Type *OpTy = getTypeByID(Record[0]);
2697      Value *Op = getValue(Record, 1, NextValueNo, OpTy);
2698      Type *ResTy = getTypeByID(Record[2]);
2699      if (!OpTy || !Op || !ResTy)
2700        return Error("Invalid VAARG record");
2701      I = new VAArgInst(Op, ResTy);
2702      InstructionList.push_back(I);
2703      break;
2704    }
2705    }
2706
2707    // Add instruction to end of current BB.  If there is no current BB, reject
2708    // this file.
2709    if (CurBB == 0) {
2710      delete I;
2711      return Error("Invalid instruction with no BB");
2712    }
2713    CurBB->getInstList().push_back(I);
2714
2715    // If this was a terminator instruction, move to the next block.
2716    if (isa<TerminatorInst>(I)) {
2717      ++CurBBNo;
2718      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
2719    }
2720
2721    // Non-void values get registered in the value table for future use.
2722    if (I && !I->getType()->isVoidTy())
2723      ValueList.AssignValue(I, NextValueNo++);
2724  }
2725
2726  // Check the function list for unresolved values.
2727  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
2728    if (A->getParent() == 0) {
2729      // We found at least one unresolved value.  Nuke them all to avoid leaks.
2730      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
2731        if ((A = dyn_cast<Argument>(ValueList[i])) && A->getParent() == 0) {
2732          A->replaceAllUsesWith(UndefValue::get(A->getType()));
2733          delete A;
2734        }
2735      }
2736      return Error("Never resolved value found in function!");
2737    }
2738  }
2739
2740  // FIXME: Check for unresolved forward-declared metadata references
2741  // and clean up leaks.
2742
2743  // See if anything took the address of blocks in this function.  If so,
2744  // resolve them now.
2745  DenseMap<Function*, std::vector<BlockAddrRefTy> >::iterator BAFRI =
2746    BlockAddrFwdRefs.find(F);
2747  if (BAFRI != BlockAddrFwdRefs.end()) {
2748    std::vector<BlockAddrRefTy> &RefList = BAFRI->second;
2749    for (unsigned i = 0, e = RefList.size(); i != e; ++i) {
2750      unsigned BlockIdx = RefList[i].first;
2751      if (BlockIdx >= FunctionBBs.size())
2752        return Error("Invalid blockaddress block #");
2753
2754      GlobalVariable *FwdRef = RefList[i].second;
2755      FwdRef->replaceAllUsesWith(BlockAddress::get(F, FunctionBBs[BlockIdx]));
2756      FwdRef->eraseFromParent();
2757    }
2758
2759    BlockAddrFwdRefs.erase(BAFRI);
2760  }
2761
2762  // Trim the value list down to the size it was before we parsed this function.
2763  ValueList.shrinkTo(ModuleValueListSize);
2764  MDValueList.shrinkTo(ModuleMDValueListSize);
2765  std::vector<BasicBlock*>().swap(FunctionBBs);
2766  return false;
2767}
2768
2769/// FindFunctionInStream - Find the function body in the bitcode stream
2770bool BitcodeReader::FindFunctionInStream(Function *F,
2771       DenseMap<Function*, uint64_t>::iterator DeferredFunctionInfoIterator) {
2772  while (DeferredFunctionInfoIterator->second == 0) {
2773    if (Stream.AtEndOfStream())
2774      return Error("Could not find Function in stream");
2775    // ParseModule will parse the next body in the stream and set its
2776    // position in the DeferredFunctionInfo map.
2777    if (ParseModule(true)) return true;
2778  }
2779  return false;
2780}
2781
2782//===----------------------------------------------------------------------===//
2783// GVMaterializer implementation
2784//===----------------------------------------------------------------------===//
2785
2786
2787bool BitcodeReader::isMaterializable(const GlobalValue *GV) const {
2788  if (const Function *F = dyn_cast<Function>(GV)) {
2789    return F->isDeclaration() &&
2790      DeferredFunctionInfo.count(const_cast<Function*>(F));
2791  }
2792  return false;
2793}
2794
2795bool BitcodeReader::Materialize(GlobalValue *GV, std::string *ErrInfo) {
2796  Function *F = dyn_cast<Function>(GV);
2797  // If it's not a function or is already material, ignore the request.
2798  if (!F || !F->isMaterializable()) return false;
2799
2800  DenseMap<Function*, uint64_t>::iterator DFII = DeferredFunctionInfo.find(F);
2801  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
2802  // If its position is recorded as 0, its body is somewhere in the stream
2803  // but we haven't seen it yet.
2804  if (DFII->second == 0)
2805    if (LazyStreamer && FindFunctionInStream(F, DFII)) return true;
2806
2807  // Move the bit stream to the saved position of the deferred function body.
2808  Stream.JumpToBit(DFII->second);
2809
2810  if (ParseFunctionBody(F)) {
2811    if (ErrInfo) *ErrInfo = ErrorString;
2812    return true;
2813  }
2814
2815  // Upgrade any old intrinsic calls in the function.
2816  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
2817       E = UpgradedIntrinsics.end(); I != E; ++I) {
2818    if (I->first != I->second) {
2819      for (Value::use_iterator UI = I->first->use_begin(),
2820           UE = I->first->use_end(); UI != UE; ) {
2821        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2822          UpgradeIntrinsicCall(CI, I->second);
2823      }
2824    }
2825  }
2826
2827  return false;
2828}
2829
2830bool BitcodeReader::isDematerializable(const GlobalValue *GV) const {
2831  const Function *F = dyn_cast<Function>(GV);
2832  if (!F || F->isDeclaration())
2833    return false;
2834  return DeferredFunctionInfo.count(const_cast<Function*>(F));
2835}
2836
2837void BitcodeReader::Dematerialize(GlobalValue *GV) {
2838  Function *F = dyn_cast<Function>(GV);
2839  // If this function isn't dematerializable, this is a noop.
2840  if (!F || !isDematerializable(F))
2841    return;
2842
2843  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
2844
2845  // Just forget the function body, we can remat it later.
2846  F->deleteBody();
2847}
2848
2849
2850bool BitcodeReader::MaterializeModule(Module *M, std::string *ErrInfo) {
2851  assert(M == TheModule &&
2852         "Can only Materialize the Module this BitcodeReader is attached to.");
2853  // Iterate over the module, deserializing any functions that are still on
2854  // disk.
2855  for (Module::iterator F = TheModule->begin(), E = TheModule->end();
2856       F != E; ++F)
2857    if (F->isMaterializable() &&
2858        Materialize(F, ErrInfo))
2859      return true;
2860
2861  // At this point, if there are any function bodies, the current bit is
2862  // pointing to the END_BLOCK record after them. Now make sure the rest
2863  // of the bits in the module have been read.
2864  if (NextUnreadBit)
2865    ParseModule(true);
2866
2867  // Upgrade any intrinsic calls that slipped through (should not happen!) and
2868  // delete the old functions to clean up. We can't do this unless the entire
2869  // module is materialized because there could always be another function body
2870  // with calls to the old function.
2871  for (std::vector<std::pair<Function*, Function*> >::iterator I =
2872       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
2873    if (I->first != I->second) {
2874      for (Value::use_iterator UI = I->first->use_begin(),
2875           UE = I->first->use_end(); UI != UE; ) {
2876        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2877          UpgradeIntrinsicCall(CI, I->second);
2878      }
2879      if (!I->first->use_empty())
2880        I->first->replaceAllUsesWith(I->second);
2881      I->first->eraseFromParent();
2882    }
2883  }
2884  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
2885
2886  return false;
2887}
2888
2889bool BitcodeReader::InitStream() {
2890  if (LazyStreamer) return InitLazyStream();
2891  return InitStreamFromBuffer();
2892}
2893
2894bool BitcodeReader::InitStreamFromBuffer() {
2895  const unsigned char *BufPtr = (const unsigned char*)Buffer->getBufferStart();
2896  const unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
2897
2898  if (Buffer->getBufferSize() & 3) {
2899    if (!isRawBitcode(BufPtr, BufEnd) && !isBitcodeWrapper(BufPtr, BufEnd))
2900      return Error("Invalid bitcode signature");
2901    else
2902      return Error("Bitcode stream should be a multiple of 4 bytes in length");
2903  }
2904
2905  // If we have a wrapper header, parse it and ignore the non-bc file contents.
2906  // The magic number is 0x0B17C0DE stored in little endian.
2907  if (isBitcodeWrapper(BufPtr, BufEnd))
2908    if (SkipBitcodeWrapperHeader(BufPtr, BufEnd, true))
2909      return Error("Invalid bitcode wrapper header");
2910
2911  StreamFile.reset(new BitstreamReader(BufPtr, BufEnd));
2912  Stream.init(*StreamFile);
2913
2914  return false;
2915}
2916
2917bool BitcodeReader::InitLazyStream() {
2918  // Check and strip off the bitcode wrapper; BitstreamReader expects never to
2919  // see it.
2920  StreamingMemoryObject *Bytes = new StreamingMemoryObject(LazyStreamer);
2921  StreamFile.reset(new BitstreamReader(Bytes));
2922  Stream.init(*StreamFile);
2923
2924  unsigned char buf[16];
2925  if (Bytes->readBytes(0, 16, buf, NULL) == -1)
2926    return Error("Bitcode stream must be at least 16 bytes in length");
2927
2928  if (!isBitcode(buf, buf + 16))
2929    return Error("Invalid bitcode signature");
2930
2931  if (isBitcodeWrapper(buf, buf + 4)) {
2932    const unsigned char *bitcodeStart = buf;
2933    const unsigned char *bitcodeEnd = buf + 16;
2934    SkipBitcodeWrapperHeader(bitcodeStart, bitcodeEnd, false);
2935    Bytes->dropLeadingBytes(bitcodeStart - buf);
2936    Bytes->setKnownObjectSize(bitcodeEnd - bitcodeStart);
2937  }
2938  return false;
2939}
2940
2941//===----------------------------------------------------------------------===//
2942// External interface
2943//===----------------------------------------------------------------------===//
2944
2945/// getLazyBitcodeModule - lazy function-at-a-time loading from a file.
2946///
2947Module *llvm::getLazyBitcodeModule(MemoryBuffer *Buffer,
2948                                   LLVMContext& Context,
2949                                   std::string *ErrMsg) {
2950  Module *M = new Module(Buffer->getBufferIdentifier(), Context);
2951  BitcodeReader *R = new BitcodeReader(Buffer, Context);
2952  M->setMaterializer(R);
2953  if (R->ParseBitcodeInto(M)) {
2954    if (ErrMsg)
2955      *ErrMsg = R->getErrorString();
2956
2957    delete M;  // Also deletes R.
2958    return 0;
2959  }
2960  // Have the BitcodeReader dtor delete 'Buffer'.
2961  R->setBufferOwned(true);
2962
2963  R->materializeForwardReferencedFunctions();
2964
2965  return M;
2966}
2967
2968
2969Module *llvm::getStreamedBitcodeModule(const std::string &name,
2970                                       DataStreamer *streamer,
2971                                       LLVMContext &Context,
2972                                       std::string *ErrMsg) {
2973  Module *M = new Module(name, Context);
2974  BitcodeReader *R = new BitcodeReader(streamer, Context);
2975  M->setMaterializer(R);
2976  if (R->ParseBitcodeInto(M)) {
2977    if (ErrMsg)
2978      *ErrMsg = R->getErrorString();
2979    delete M;  // Also deletes R.
2980    return 0;
2981  }
2982  R->setBufferOwned(false); // no buffer to delete
2983  return M;
2984}
2985
2986/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
2987/// If an error occurs, return null and fill in *ErrMsg if non-null.
2988Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, LLVMContext& Context,
2989                               std::string *ErrMsg){
2990  Module *M = getLazyBitcodeModule(Buffer, Context, ErrMsg);
2991  if (!M) return 0;
2992
2993  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
2994  // there was an error.
2995  static_cast<BitcodeReader*>(M->getMaterializer())->setBufferOwned(false);
2996
2997  // Read in the entire module, and destroy the BitcodeReader.
2998  if (M->MaterializeAllPermanently(ErrMsg)) {
2999    delete M;
3000    return 0;
3001  }
3002
3003  // TODO: Restore the use-lists to the in-memory state when the bitcode was
3004  // written.  We must defer until the Module has been fully materialized.
3005
3006  return M;
3007}
3008
3009std::string llvm::getBitcodeTargetTriple(MemoryBuffer *Buffer,
3010                                         LLVMContext& Context,
3011                                         std::string *ErrMsg) {
3012  BitcodeReader *R = new BitcodeReader(Buffer, Context);
3013  // Don't let the BitcodeReader dtor delete 'Buffer'.
3014  R->setBufferOwned(false);
3015
3016  std::string Triple("");
3017  if (R->ParseTriple(Triple))
3018    if (ErrMsg)
3019      *ErrMsg = R->getErrorString();
3020
3021  delete R;
3022  return Triple;
3023}
3024