BitcodeReader.cpp revision ed84062812c7b8a82d0e8128a22aa1aa07a14d79 
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(Record[i+1]);
480        Record[i+1] = ReconstitutedAttr.Raw();
481      }
482
483      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
484        if (Attributes(Record[i+1]).hasAttributes())
485          Attrs.push_back(AttributeWithIndex::get(Record[i],
486                                                  Attributes(Record[i+1])));
487      }
488
489      MAttributes.push_back(AttrListPtr::get(Attrs));
490      Attrs.clear();
491      break;
492    }
493    }
494  }
495}
496
497bool BitcodeReader::ParseTypeTable() {
498  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID_NEW))
499    return Error("Malformed block record");
500
501  return ParseTypeTableBody();
502}
503
504bool BitcodeReader::ParseTypeTableBody() {
505  if (!TypeList.empty())
506    return Error("Multiple TYPE_BLOCKs found!");
507
508  SmallVector<uint64_t, 64> Record;
509  unsigned NumRecords = 0;
510
511  SmallString<64> TypeName;
512
513  // Read all the records for this type table.
514  while (1) {
515    unsigned Code = Stream.ReadCode();
516    if (Code == bitc::END_BLOCK) {
517      if (NumRecords != TypeList.size())
518        return Error("Invalid type forward reference in TYPE_BLOCK");
519      if (Stream.ReadBlockEnd())
520        return Error("Error at end of type table block");
521      return false;
522    }
523
524    if (Code == bitc::ENTER_SUBBLOCK) {
525      // No known subblocks, always skip them.
526      Stream.ReadSubBlockID();
527      if (Stream.SkipBlock())
528        return Error("Malformed block record");
529      continue;
530    }
531
532    if (Code == bitc::DEFINE_ABBREV) {
533      Stream.ReadAbbrevRecord();
534      continue;
535    }
536
537    // Read a record.
538    Record.clear();
539    Type *ResultTy = 0;
540    switch (Stream.ReadRecord(Code, Record)) {
541    default: return Error("unknown type in type table");
542    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
543      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
544      // type list.  This allows us to reserve space.
545      if (Record.size() < 1)
546        return Error("Invalid TYPE_CODE_NUMENTRY record");
547      TypeList.resize(Record[0]);
548      continue;
549    case bitc::TYPE_CODE_VOID:      // VOID
550      ResultTy = Type::getVoidTy(Context);
551      break;
552    case bitc::TYPE_CODE_HALF:     // HALF
553      ResultTy = Type::getHalfTy(Context);
554      break;
555    case bitc::TYPE_CODE_FLOAT:     // FLOAT
556      ResultTy = Type::getFloatTy(Context);
557      break;
558    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
559      ResultTy = Type::getDoubleTy(Context);
560      break;
561    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
562      ResultTy = Type::getX86_FP80Ty(Context);
563      break;
564    case bitc::TYPE_CODE_FP128:     // FP128
565      ResultTy = Type::getFP128Ty(Context);
566      break;
567    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
568      ResultTy = Type::getPPC_FP128Ty(Context);
569      break;
570    case bitc::TYPE_CODE_LABEL:     // LABEL
571      ResultTy = Type::getLabelTy(Context);
572      break;
573    case bitc::TYPE_CODE_METADATA:  // METADATA
574      ResultTy = Type::getMetadataTy(Context);
575      break;
576    case bitc::TYPE_CODE_X86_MMX:   // X86_MMX
577      ResultTy = Type::getX86_MMXTy(Context);
578      break;
579    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
580      if (Record.size() < 1)
581        return Error("Invalid Integer type record");
582
583      ResultTy = IntegerType::get(Context, Record[0]);
584      break;
585    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
586                                    //          [pointee type, address space]
587      if (Record.size() < 1)
588        return Error("Invalid POINTER type record");
589      unsigned AddressSpace = 0;
590      if (Record.size() == 2)
591        AddressSpace = Record[1];
592      ResultTy = getTypeByID(Record[0]);
593      if (ResultTy == 0) return Error("invalid element type in pointer type");
594      ResultTy = PointerType::get(ResultTy, AddressSpace);
595      break;
596    }
597    case bitc::TYPE_CODE_FUNCTION_OLD: {
598      // FIXME: attrid is dead, remove it in LLVM 4.0
599      // FUNCTION: [vararg, attrid, retty, paramty x N]
600      if (Record.size() < 3)
601        return Error("Invalid FUNCTION type record");
602      SmallVector<Type*, 8> ArgTys;
603      for (unsigned i = 3, e = Record.size(); i != e; ++i) {
604        if (Type *T = getTypeByID(Record[i]))
605          ArgTys.push_back(T);
606        else
607          break;
608      }
609
610      ResultTy = getTypeByID(Record[2]);
611      if (ResultTy == 0 || ArgTys.size() < Record.size()-3)
612        return Error("invalid type in function type");
613
614      ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
615      break;
616    }
617    case bitc::TYPE_CODE_FUNCTION: {
618      // FUNCTION: [vararg, retty, paramty x N]
619      if (Record.size() < 2)
620        return Error("Invalid FUNCTION type record");
621      SmallVector<Type*, 8> ArgTys;
622      for (unsigned i = 2, e = Record.size(); i != e; ++i) {
623        if (Type *T = getTypeByID(Record[i]))
624          ArgTys.push_back(T);
625        else
626          break;
627      }
628
629      ResultTy = getTypeByID(Record[1]);
630      if (ResultTy == 0 || ArgTys.size() < Record.size()-2)
631        return Error("invalid type in function type");
632
633      ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
634      break;
635    }
636    case bitc::TYPE_CODE_STRUCT_ANON: {  // STRUCT: [ispacked, eltty x N]
637      if (Record.size() < 1)
638        return Error("Invalid STRUCT type record");
639      SmallVector<Type*, 8> EltTys;
640      for (unsigned i = 1, e = Record.size(); i != e; ++i) {
641        if (Type *T = getTypeByID(Record[i]))
642          EltTys.push_back(T);
643        else
644          break;
645      }
646      if (EltTys.size() != Record.size()-1)
647        return Error("invalid type in struct type");
648      ResultTy = StructType::get(Context, EltTys, Record[0]);
649      break;
650    }
651    case bitc::TYPE_CODE_STRUCT_NAME:   // STRUCT_NAME: [strchr x N]
652      if (ConvertToString(Record, 0, TypeName))
653        return Error("Invalid STRUCT_NAME record");
654      continue;
655
656    case bitc::TYPE_CODE_STRUCT_NAMED: { // STRUCT: [ispacked, eltty x N]
657      if (Record.size() < 1)
658        return Error("Invalid STRUCT type record");
659
660      if (NumRecords >= TypeList.size())
661        return Error("invalid TYPE table");
662
663      // Check to see if this was forward referenced, if so fill in the temp.
664      StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
665      if (Res) {
666        Res->setName(TypeName);
667        TypeList[NumRecords] = 0;
668      } else  // Otherwise, create a new struct.
669        Res = StructType::create(Context, TypeName);
670      TypeName.clear();
671
672      SmallVector<Type*, 8> EltTys;
673      for (unsigned i = 1, e = Record.size(); i != e; ++i) {
674        if (Type *T = getTypeByID(Record[i]))
675          EltTys.push_back(T);
676        else
677          break;
678      }
679      if (EltTys.size() != Record.size()-1)
680        return Error("invalid STRUCT type record");
681      Res->setBody(EltTys, Record[0]);
682      ResultTy = Res;
683      break;
684    }
685    case bitc::TYPE_CODE_OPAQUE: {       // OPAQUE: []
686      if (Record.size() != 1)
687        return Error("Invalid OPAQUE type record");
688
689      if (NumRecords >= TypeList.size())
690        return Error("invalid TYPE table");
691
692      // Check to see if this was forward referenced, if so fill in the temp.
693      StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
694      if (Res) {
695        Res->setName(TypeName);
696        TypeList[NumRecords] = 0;
697      } else  // Otherwise, create a new struct with no body.
698        Res = StructType::create(Context, TypeName);
699      TypeName.clear();
700      ResultTy = Res;
701      break;
702    }
703    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
704      if (Record.size() < 2)
705        return Error("Invalid ARRAY type record");
706      if ((ResultTy = getTypeByID(Record[1])))
707        ResultTy = ArrayType::get(ResultTy, Record[0]);
708      else
709        return Error("Invalid ARRAY type element");
710      break;
711    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
712      if (Record.size() < 2)
713        return Error("Invalid VECTOR type record");
714      if ((ResultTy = getTypeByID(Record[1])))
715        ResultTy = VectorType::get(ResultTy, Record[0]);
716      else
717        return Error("Invalid ARRAY type element");
718      break;
719    }
720
721    if (NumRecords >= TypeList.size())
722      return Error("invalid TYPE table");
723    assert(ResultTy && "Didn't read a type?");
724    assert(TypeList[NumRecords] == 0 && "Already read type?");
725    TypeList[NumRecords++] = ResultTy;
726  }
727}
728
729bool BitcodeReader::ParseValueSymbolTable() {
730  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
731    return Error("Malformed block record");
732
733  SmallVector<uint64_t, 64> Record;
734
735  // Read all the records for this value table.
736  SmallString<128> ValueName;
737  while (1) {
738    unsigned Code = Stream.ReadCode();
739    if (Code == bitc::END_BLOCK) {
740      if (Stream.ReadBlockEnd())
741        return Error("Error at end of value symbol table block");
742      return false;
743    }
744    if (Code == bitc::ENTER_SUBBLOCK) {
745      // No known subblocks, always skip them.
746      Stream.ReadSubBlockID();
747      if (Stream.SkipBlock())
748        return Error("Malformed block record");
749      continue;
750    }
751
752    if (Code == bitc::DEFINE_ABBREV) {
753      Stream.ReadAbbrevRecord();
754      continue;
755    }
756
757    // Read a record.
758    Record.clear();
759    switch (Stream.ReadRecord(Code, Record)) {
760    default:  // Default behavior: unknown type.
761      break;
762    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
763      if (ConvertToString(Record, 1, ValueName))
764        return Error("Invalid VST_ENTRY record");
765      unsigned ValueID = Record[0];
766      if (ValueID >= ValueList.size())
767        return Error("Invalid Value ID in VST_ENTRY record");
768      Value *V = ValueList[ValueID];
769
770      V->setName(StringRef(ValueName.data(), ValueName.size()));
771      ValueName.clear();
772      break;
773    }
774    case bitc::VST_CODE_BBENTRY: {
775      if (ConvertToString(Record, 1, ValueName))
776        return Error("Invalid VST_BBENTRY record");
777      BasicBlock *BB = getBasicBlock(Record[0]);
778      if (BB == 0)
779        return Error("Invalid BB ID in VST_BBENTRY record");
780
781      BB->setName(StringRef(ValueName.data(), ValueName.size()));
782      ValueName.clear();
783      break;
784    }
785    }
786  }
787}
788
789bool BitcodeReader::ParseMetadata() {
790  unsigned NextMDValueNo = MDValueList.size();
791
792  if (Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
793    return Error("Malformed block record");
794
795  SmallVector<uint64_t, 64> Record;
796
797  // Read all the records.
798  while (1) {
799    unsigned Code = Stream.ReadCode();
800    if (Code == bitc::END_BLOCK) {
801      if (Stream.ReadBlockEnd())
802        return Error("Error at end of PARAMATTR block");
803      return false;
804    }
805
806    if (Code == bitc::ENTER_SUBBLOCK) {
807      // No known subblocks, always skip them.
808      Stream.ReadSubBlockID();
809      if (Stream.SkipBlock())
810        return Error("Malformed block record");
811      continue;
812    }
813
814    if (Code == bitc::DEFINE_ABBREV) {
815      Stream.ReadAbbrevRecord();
816      continue;
817    }
818
819    bool IsFunctionLocal = false;
820    // Read a record.
821    Record.clear();
822    Code = Stream.ReadRecord(Code, Record);
823    switch (Code) {
824    default:  // Default behavior: ignore.
825      break;
826    case bitc::METADATA_NAME: {
827      // Read named of the named metadata.
828      SmallString<8> Name(Record.begin(), Record.end());
829      Record.clear();
830      Code = Stream.ReadCode();
831
832      // METADATA_NAME is always followed by METADATA_NAMED_NODE.
833      unsigned NextBitCode = Stream.ReadRecord(Code, Record);
834      assert(NextBitCode == bitc::METADATA_NAMED_NODE); (void)NextBitCode;
835
836      // Read named metadata elements.
837      unsigned Size = Record.size();
838      NamedMDNode *NMD = TheModule->getOrInsertNamedMetadata(Name);
839      for (unsigned i = 0; i != Size; ++i) {
840        MDNode *MD = dyn_cast<MDNode>(MDValueList.getValueFwdRef(Record[i]));
841        if (MD == 0)
842          return Error("Malformed metadata record");
843        NMD->addOperand(MD);
844      }
845      break;
846    }
847    case bitc::METADATA_FN_NODE:
848      IsFunctionLocal = true;
849      // fall-through
850    case bitc::METADATA_NODE: {
851      if (Record.size() % 2 == 1)
852        return Error("Invalid METADATA_NODE record");
853
854      unsigned Size = Record.size();
855      SmallVector<Value*, 8> Elts;
856      for (unsigned i = 0; i != Size; i += 2) {
857        Type *Ty = getTypeByID(Record[i]);
858        if (!Ty) return Error("Invalid METADATA_NODE record");
859        if (Ty->isMetadataTy())
860          Elts.push_back(MDValueList.getValueFwdRef(Record[i+1]));
861        else if (!Ty->isVoidTy())
862          Elts.push_back(ValueList.getValueFwdRef(Record[i+1], Ty));
863        else
864          Elts.push_back(NULL);
865      }
866      Value *V = MDNode::getWhenValsUnresolved(Context, Elts, IsFunctionLocal);
867      IsFunctionLocal = false;
868      MDValueList.AssignValue(V, NextMDValueNo++);
869      break;
870    }
871    case bitc::METADATA_STRING: {
872      SmallString<8> String(Record.begin(), Record.end());
873      Value *V = MDString::get(Context, String);
874      MDValueList.AssignValue(V, NextMDValueNo++);
875      break;
876    }
877    case bitc::METADATA_KIND: {
878      if (Record.size() < 2)
879        return Error("Invalid METADATA_KIND record");
880
881      unsigned Kind = Record[0];
882      SmallString<8> Name(Record.begin()+1, Record.end());
883
884      unsigned NewKind = TheModule->getMDKindID(Name.str());
885      if (!MDKindMap.insert(std::make_pair(Kind, NewKind)).second)
886        return Error("Conflicting METADATA_KIND records");
887      break;
888    }
889    }
890  }
891}
892
893/// decodeSignRotatedValue - Decode a signed value stored with the sign bit in
894/// the LSB for dense VBR encoding.
895uint64_t BitcodeReader::decodeSignRotatedValue(uint64_t V) {
896  if ((V & 1) == 0)
897    return V >> 1;
898  if (V != 1)
899    return -(V >> 1);
900  // There is no such thing as -0 with integers.  "-0" really means MININT.
901  return 1ULL << 63;
902}
903
904/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
905/// values and aliases that we can.
906bool BitcodeReader::ResolveGlobalAndAliasInits() {
907  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
908  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
909
910  GlobalInitWorklist.swap(GlobalInits);
911  AliasInitWorklist.swap(AliasInits);
912
913  while (!GlobalInitWorklist.empty()) {
914    unsigned ValID = GlobalInitWorklist.back().second;
915    if (ValID >= ValueList.size()) {
916      // Not ready to resolve this yet, it requires something later in the file.
917      GlobalInits.push_back(GlobalInitWorklist.back());
918    } else {
919      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
920        GlobalInitWorklist.back().first->setInitializer(C);
921      else
922        return Error("Global variable initializer is not a constant!");
923    }
924    GlobalInitWorklist.pop_back();
925  }
926
927  while (!AliasInitWorklist.empty()) {
928    unsigned ValID = AliasInitWorklist.back().second;
929    if (ValID >= ValueList.size()) {
930      AliasInits.push_back(AliasInitWorklist.back());
931    } else {
932      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
933        AliasInitWorklist.back().first->setAliasee(C);
934      else
935        return Error("Alias initializer is not a constant!");
936    }
937    AliasInitWorklist.pop_back();
938  }
939  return false;
940}
941
942static APInt ReadWideAPInt(ArrayRef<uint64_t> Vals, unsigned TypeBits) {
943  SmallVector<uint64_t, 8> Words(Vals.size());
944  std::transform(Vals.begin(), Vals.end(), Words.begin(),
945                 BitcodeReader::decodeSignRotatedValue);
946
947  return APInt(TypeBits, Words);
948}
949
950bool BitcodeReader::ParseConstants() {
951  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
952    return Error("Malformed block record");
953
954  SmallVector<uint64_t, 64> Record;
955
956  // Read all the records for this value table.
957  Type *CurTy = Type::getInt32Ty(Context);
958  unsigned NextCstNo = ValueList.size();
959  while (1) {
960    unsigned Code = Stream.ReadCode();
961    if (Code == bitc::END_BLOCK)
962      break;
963
964    if (Code == bitc::ENTER_SUBBLOCK) {
965      // No known subblocks, always skip them.
966      Stream.ReadSubBlockID();
967      if (Stream.SkipBlock())
968        return Error("Malformed block record");
969      continue;
970    }
971
972    if (Code == bitc::DEFINE_ABBREV) {
973      Stream.ReadAbbrevRecord();
974      continue;
975    }
976
977    // Read a record.
978    Record.clear();
979    Value *V = 0;
980    unsigned BitCode = Stream.ReadRecord(Code, Record);
981    switch (BitCode) {
982    default:  // Default behavior: unknown constant
983    case bitc::CST_CODE_UNDEF:     // UNDEF
984      V = UndefValue::get(CurTy);
985      break;
986    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
987      if (Record.empty())
988        return Error("Malformed CST_SETTYPE record");
989      if (Record[0] >= TypeList.size())
990        return Error("Invalid Type ID in CST_SETTYPE record");
991      CurTy = TypeList[Record[0]];
992      continue;  // Skip the ValueList manipulation.
993    case bitc::CST_CODE_NULL:      // NULL
994      V = Constant::getNullValue(CurTy);
995      break;
996    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
997      if (!CurTy->isIntegerTy() || Record.empty())
998        return Error("Invalid CST_INTEGER record");
999      V = ConstantInt::get(CurTy, decodeSignRotatedValue(Record[0]));
1000      break;
1001    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
1002      if (!CurTy->isIntegerTy() || Record.empty())
1003        return Error("Invalid WIDE_INTEGER record");
1004
1005      APInt VInt = ReadWideAPInt(Record,
1006                                 cast<IntegerType>(CurTy)->getBitWidth());
1007      V = ConstantInt::get(Context, VInt);
1008
1009      break;
1010    }
1011    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
1012      if (Record.empty())
1013        return Error("Invalid FLOAT record");
1014      if (CurTy->isHalfTy())
1015        V = ConstantFP::get(Context, APFloat(APInt(16, (uint16_t)Record[0])));
1016      else if (CurTy->isFloatTy())
1017        V = ConstantFP::get(Context, APFloat(APInt(32, (uint32_t)Record[0])));
1018      else if (CurTy->isDoubleTy())
1019        V = ConstantFP::get(Context, APFloat(APInt(64, Record[0])));
1020      else if (CurTy->isX86_FP80Ty()) {
1021        // Bits are not stored the same way as a normal i80 APInt, compensate.
1022        uint64_t Rearrange[2];
1023        Rearrange[0] = (Record[1] & 0xffffLL) | (Record[0] << 16);
1024        Rearrange[1] = Record[0] >> 48;
1025        V = ConstantFP::get(Context, APFloat(APInt(80, Rearrange)));
1026      } else if (CurTy->isFP128Ty())
1027        V = ConstantFP::get(Context, APFloat(APInt(128, Record), true));
1028      else if (CurTy->isPPC_FP128Ty())
1029        V = ConstantFP::get(Context, APFloat(APInt(128, Record)));
1030      else
1031        V = UndefValue::get(CurTy);
1032      break;
1033    }
1034
1035    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
1036      if (Record.empty())
1037        return Error("Invalid CST_AGGREGATE record");
1038
1039      unsigned Size = Record.size();
1040      SmallVector<Constant*, 16> Elts;
1041
1042      if (StructType *STy = dyn_cast<StructType>(CurTy)) {
1043        for (unsigned i = 0; i != Size; ++i)
1044          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
1045                                                     STy->getElementType(i)));
1046        V = ConstantStruct::get(STy, Elts);
1047      } else if (ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
1048        Type *EltTy = ATy->getElementType();
1049        for (unsigned i = 0; i != Size; ++i)
1050          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1051        V = ConstantArray::get(ATy, Elts);
1052      } else if (VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
1053        Type *EltTy = VTy->getElementType();
1054        for (unsigned i = 0; i != Size; ++i)
1055          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1056        V = ConstantVector::get(Elts);
1057      } else {
1058        V = UndefValue::get(CurTy);
1059      }
1060      break;
1061    }
1062    case bitc::CST_CODE_STRING:    // STRING: [values]
1063    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
1064      if (Record.empty())
1065        return Error("Invalid CST_STRING record");
1066
1067      SmallString<16> Elts(Record.begin(), Record.end());
1068      V = ConstantDataArray::getString(Context, Elts,
1069                                       BitCode == bitc::CST_CODE_CSTRING);
1070      break;
1071    }
1072    case bitc::CST_CODE_DATA: {// DATA: [n x value]
1073      if (Record.empty())
1074        return Error("Invalid CST_DATA record");
1075
1076      Type *EltTy = cast<SequentialType>(CurTy)->getElementType();
1077      unsigned Size = Record.size();
1078
1079      if (EltTy->isIntegerTy(8)) {
1080        SmallVector<uint8_t, 16> Elts(Record.begin(), Record.end());
1081        if (isa<VectorType>(CurTy))
1082          V = ConstantDataVector::get(Context, Elts);
1083        else
1084          V = ConstantDataArray::get(Context, Elts);
1085      } else if (EltTy->isIntegerTy(16)) {
1086        SmallVector<uint16_t, 16> Elts(Record.begin(), Record.end());
1087        if (isa<VectorType>(CurTy))
1088          V = ConstantDataVector::get(Context, Elts);
1089        else
1090          V = ConstantDataArray::get(Context, Elts);
1091      } else if (EltTy->isIntegerTy(32)) {
1092        SmallVector<uint32_t, 16> Elts(Record.begin(), Record.end());
1093        if (isa<VectorType>(CurTy))
1094          V = ConstantDataVector::get(Context, Elts);
1095        else
1096          V = ConstantDataArray::get(Context, Elts);
1097      } else if (EltTy->isIntegerTy(64)) {
1098        SmallVector<uint64_t, 16> Elts(Record.begin(), Record.end());
1099        if (isa<VectorType>(CurTy))
1100          V = ConstantDataVector::get(Context, Elts);
1101        else
1102          V = ConstantDataArray::get(Context, Elts);
1103      } else if (EltTy->isFloatTy()) {
1104        SmallVector<float, 16> Elts(Size);
1105        std::transform(Record.begin(), Record.end(), Elts.begin(), BitsToFloat);
1106        if (isa<VectorType>(CurTy))
1107          V = ConstantDataVector::get(Context, Elts);
1108        else
1109          V = ConstantDataArray::get(Context, Elts);
1110      } else if (EltTy->isDoubleTy()) {
1111        SmallVector<double, 16> Elts(Size);
1112        std::transform(Record.begin(), Record.end(), Elts.begin(),
1113                       BitsToDouble);
1114        if (isa<VectorType>(CurTy))
1115          V = ConstantDataVector::get(Context, Elts);
1116        else
1117          V = ConstantDataArray::get(Context, Elts);
1118      } else {
1119        return Error("Unknown element type in CE_DATA");
1120      }
1121      break;
1122    }
1123
1124    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
1125      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
1126      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
1127      if (Opc < 0) {
1128        V = UndefValue::get(CurTy);  // Unknown binop.
1129      } else {
1130        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
1131        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
1132        unsigned Flags = 0;
1133        if (Record.size() >= 4) {
1134          if (Opc == Instruction::Add ||
1135              Opc == Instruction::Sub ||
1136              Opc == Instruction::Mul ||
1137              Opc == Instruction::Shl) {
1138            if (Record[3] & (1 << bitc::OBO_NO_SIGNED_WRAP))
1139              Flags |= OverflowingBinaryOperator::NoSignedWrap;
1140            if (Record[3] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
1141              Flags |= OverflowingBinaryOperator::NoUnsignedWrap;
1142          } else if (Opc == Instruction::SDiv ||
1143                     Opc == Instruction::UDiv ||
1144                     Opc == Instruction::LShr ||
1145                     Opc == Instruction::AShr) {
1146            if (Record[3] & (1 << bitc::PEO_EXACT))
1147              Flags |= SDivOperator::IsExact;
1148          }
1149        }
1150        V = ConstantExpr::get(Opc, LHS, RHS, Flags);
1151      }
1152      break;
1153    }
1154    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
1155      if (Record.size() < 3) return Error("Invalid CE_CAST record");
1156      int Opc = GetDecodedCastOpcode(Record[0]);
1157      if (Opc < 0) {
1158        V = UndefValue::get(CurTy);  // Unknown cast.
1159      } else {
1160        Type *OpTy = getTypeByID(Record[1]);
1161        if (!OpTy) return Error("Invalid CE_CAST record");
1162        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
1163        V = ConstantExpr::getCast(Opc, Op, CurTy);
1164      }
1165      break;
1166    }
1167    case bitc::CST_CODE_CE_INBOUNDS_GEP:
1168    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
1169      if (Record.size() & 1) return Error("Invalid CE_GEP record");
1170      SmallVector<Constant*, 16> Elts;
1171      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
1172        Type *ElTy = getTypeByID(Record[i]);
1173        if (!ElTy) return Error("Invalid CE_GEP record");
1174        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
1175      }
1176      ArrayRef<Constant *> Indices(Elts.begin() + 1, Elts.end());
1177      V = ConstantExpr::getGetElementPtr(Elts[0], Indices,
1178                                         BitCode ==
1179                                           bitc::CST_CODE_CE_INBOUNDS_GEP);
1180      break;
1181    }
1182    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
1183      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
1184      V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
1185                                                              Type::getInt1Ty(Context)),
1186                                  ValueList.getConstantFwdRef(Record[1],CurTy),
1187                                  ValueList.getConstantFwdRef(Record[2],CurTy));
1188      break;
1189    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
1190      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
1191      VectorType *OpTy =
1192        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1193      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
1194      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1195      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
1196      V = ConstantExpr::getExtractElement(Op0, Op1);
1197      break;
1198    }
1199    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
1200      VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1201      if (Record.size() < 3 || OpTy == 0)
1202        return Error("Invalid CE_INSERTELT record");
1203      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1204      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
1205                                                  OpTy->getElementType());
1206      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
1207      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
1208      break;
1209    }
1210    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
1211      VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1212      if (Record.size() < 3 || OpTy == 0)
1213        return Error("Invalid CE_SHUFFLEVEC record");
1214      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1215      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
1216      Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
1217                                                 OpTy->getNumElements());
1218      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
1219      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1220      break;
1221    }
1222    case bitc::CST_CODE_CE_SHUFVEC_EX: { // [opty, opval, opval, opval]
1223      VectorType *RTy = dyn_cast<VectorType>(CurTy);
1224      VectorType *OpTy =
1225        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1226      if (Record.size() < 4 || RTy == 0 || OpTy == 0)
1227        return Error("Invalid CE_SHUFVEC_EX record");
1228      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1229      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1230      Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
1231                                                 RTy->getNumElements());
1232      Constant *Op2 = ValueList.getConstantFwdRef(Record[3], ShufTy);
1233      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1234      break;
1235    }
1236    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
1237      if (Record.size() < 4) return Error("Invalid CE_CMP record");
1238      Type *OpTy = getTypeByID(Record[0]);
1239      if (OpTy == 0) return Error("Invalid CE_CMP record");
1240      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1241      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1242
1243      if (OpTy->isFPOrFPVectorTy())
1244        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
1245      else
1246        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
1247      break;
1248    }
1249    // This maintains backward compatibility, pre-asm dialect keywords.
1250    // FIXME: Remove with the 4.0 release.
1251    case bitc::CST_CODE_INLINEASM_OLD: {
1252      if (Record.size() < 2) return Error("Invalid INLINEASM record");
1253      std::string AsmStr, ConstrStr;
1254      bool HasSideEffects = Record[0] & 1;
1255      bool IsAlignStack = Record[0] >> 1;
1256      unsigned AsmStrSize = Record[1];
1257      if (2+AsmStrSize >= Record.size())
1258        return Error("Invalid INLINEASM record");
1259      unsigned ConstStrSize = Record[2+AsmStrSize];
1260      if (3+AsmStrSize+ConstStrSize > Record.size())
1261        return Error("Invalid INLINEASM record");
1262
1263      for (unsigned i = 0; i != AsmStrSize; ++i)
1264        AsmStr += (char)Record[2+i];
1265      for (unsigned i = 0; i != ConstStrSize; ++i)
1266        ConstrStr += (char)Record[3+AsmStrSize+i];
1267      PointerType *PTy = cast<PointerType>(CurTy);
1268      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
1269                         AsmStr, ConstrStr, HasSideEffects, IsAlignStack);
1270      break;
1271    }
1272    // This version adds support for the asm dialect keywords (e.g.,
1273    // inteldialect).
1274    case bitc::CST_CODE_INLINEASM: {
1275      if (Record.size() < 2) return Error("Invalid INLINEASM record");
1276      std::string AsmStr, ConstrStr;
1277      bool HasSideEffects = Record[0] & 1;
1278      bool IsAlignStack = (Record[0] >> 1) & 1;
1279      unsigned AsmDialect = Record[0] >> 2;
1280      unsigned AsmStrSize = Record[1];
1281      if (2+AsmStrSize >= Record.size())
1282        return Error("Invalid INLINEASM record");
1283      unsigned ConstStrSize = Record[2+AsmStrSize];
1284      if (3+AsmStrSize+ConstStrSize > Record.size())
1285        return Error("Invalid INLINEASM record");
1286
1287      for (unsigned i = 0; i != AsmStrSize; ++i)
1288        AsmStr += (char)Record[2+i];
1289      for (unsigned i = 0; i != ConstStrSize; ++i)
1290        ConstrStr += (char)Record[3+AsmStrSize+i];
1291      PointerType *PTy = cast<PointerType>(CurTy);
1292      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
1293                         AsmStr, ConstrStr, HasSideEffects, IsAlignStack,
1294                         InlineAsm::AsmDialect(AsmDialect));
1295      break;
1296    }
1297    case bitc::CST_CODE_BLOCKADDRESS:{
1298      if (Record.size() < 3) return Error("Invalid CE_BLOCKADDRESS record");
1299      Type *FnTy = getTypeByID(Record[0]);
1300      if (FnTy == 0) return Error("Invalid CE_BLOCKADDRESS record");
1301      Function *Fn =
1302        dyn_cast_or_null<Function>(ValueList.getConstantFwdRef(Record[1],FnTy));
1303      if (Fn == 0) return Error("Invalid CE_BLOCKADDRESS record");
1304
1305      // If the function is already parsed we can insert the block address right
1306      // away.
1307      if (!Fn->empty()) {
1308        Function::iterator BBI = Fn->begin(), BBE = Fn->end();
1309        for (size_t I = 0, E = Record[2]; I != E; ++I) {
1310          if (BBI == BBE)
1311            return Error("Invalid blockaddress block #");
1312          ++BBI;
1313        }
1314        V = BlockAddress::get(Fn, BBI);
1315      } else {
1316        // Otherwise insert a placeholder and remember it so it can be inserted
1317        // when the function is parsed.
1318        GlobalVariable *FwdRef = new GlobalVariable(*Fn->getParent(),
1319                                                    Type::getInt8Ty(Context),
1320                                            false, GlobalValue::InternalLinkage,
1321                                                    0, "");
1322        BlockAddrFwdRefs[Fn].push_back(std::make_pair(Record[2], FwdRef));
1323        V = FwdRef;
1324      }
1325      break;
1326    }
1327    }
1328
1329    ValueList.AssignValue(V, NextCstNo);
1330    ++NextCstNo;
1331  }
1332
1333  if (NextCstNo != ValueList.size())
1334    return Error("Invalid constant reference!");
1335
1336  if (Stream.ReadBlockEnd())
1337    return Error("Error at end of constants block");
1338
1339  // Once all the constants have been read, go through and resolve forward
1340  // references.
1341  ValueList.ResolveConstantForwardRefs();
1342  return false;
1343}
1344
1345bool BitcodeReader::ParseUseLists() {
1346  if (Stream.EnterSubBlock(bitc::USELIST_BLOCK_ID))
1347    return Error("Malformed block record");
1348
1349  SmallVector<uint64_t, 64> Record;
1350
1351  // Read all the records.
1352  while (1) {
1353    unsigned Code = Stream.ReadCode();
1354    if (Code == bitc::END_BLOCK) {
1355      if (Stream.ReadBlockEnd())
1356        return Error("Error at end of use-list table block");
1357      return false;
1358    }
1359
1360    if (Code == bitc::ENTER_SUBBLOCK) {
1361      // No known subblocks, always skip them.
1362      Stream.ReadSubBlockID();
1363      if (Stream.SkipBlock())
1364        return Error("Malformed block record");
1365      continue;
1366    }
1367
1368    if (Code == bitc::DEFINE_ABBREV) {
1369      Stream.ReadAbbrevRecord();
1370      continue;
1371    }
1372
1373    // Read a use list record.
1374    Record.clear();
1375    switch (Stream.ReadRecord(Code, Record)) {
1376    default:  // Default behavior: unknown type.
1377      break;
1378    case bitc::USELIST_CODE_ENTRY: { // USELIST_CODE_ENTRY: TBD.
1379      unsigned RecordLength = Record.size();
1380      if (RecordLength < 1)
1381        return Error ("Invalid UseList reader!");
1382      UseListRecords.push_back(Record);
1383      break;
1384    }
1385    }
1386  }
1387}
1388
1389/// RememberAndSkipFunctionBody - When we see the block for a function body,
1390/// remember where it is and then skip it.  This lets us lazily deserialize the
1391/// functions.
1392bool BitcodeReader::RememberAndSkipFunctionBody() {
1393  // Get the function we are talking about.
1394  if (FunctionsWithBodies.empty())
1395    return Error("Insufficient function protos");
1396
1397  Function *Fn = FunctionsWithBodies.back();
1398  FunctionsWithBodies.pop_back();
1399
1400  // Save the current stream state.
1401  uint64_t CurBit = Stream.GetCurrentBitNo();
1402  DeferredFunctionInfo[Fn] = CurBit;
1403
1404  // Skip over the function block for now.
1405  if (Stream.SkipBlock())
1406    return Error("Malformed block record");
1407  return false;
1408}
1409
1410bool BitcodeReader::GlobalCleanup() {
1411  // Patch the initializers for globals and aliases up.
1412  ResolveGlobalAndAliasInits();
1413  if (!GlobalInits.empty() || !AliasInits.empty())
1414    return Error("Malformed global initializer set");
1415
1416  // Look for intrinsic functions which need to be upgraded at some point
1417  for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
1418       FI != FE; ++FI) {
1419    Function *NewFn;
1420    if (UpgradeIntrinsicFunction(FI, NewFn))
1421      UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
1422  }
1423
1424  // Look for global variables which need to be renamed.
1425  for (Module::global_iterator
1426         GI = TheModule->global_begin(), GE = TheModule->global_end();
1427       GI != GE; ++GI)
1428    UpgradeGlobalVariable(GI);
1429  // Force deallocation of memory for these vectors to favor the client that
1430  // want lazy deserialization.
1431  std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
1432  std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
1433  return false;
1434}
1435
1436bool BitcodeReader::ParseModule(bool Resume) {
1437  if (Resume)
1438    Stream.JumpToBit(NextUnreadBit);
1439  else if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
1440    return Error("Malformed block record");
1441
1442  SmallVector<uint64_t, 64> Record;
1443  std::vector<std::string> SectionTable;
1444  std::vector<std::string> GCTable;
1445
1446  // Read all the records for this module.
1447  while (!Stream.AtEndOfStream()) {
1448    unsigned Code = Stream.ReadCode();
1449    if (Code == bitc::END_BLOCK) {
1450      if (Stream.ReadBlockEnd())
1451        return Error("Error at end of module block");
1452
1453      return GlobalCleanup();
1454    }
1455
1456    if (Code == bitc::ENTER_SUBBLOCK) {
1457      switch (Stream.ReadSubBlockID()) {
1458      default:  // Skip unknown content.
1459        if (Stream.SkipBlock())
1460          return Error("Malformed block record");
1461        break;
1462      case bitc::BLOCKINFO_BLOCK_ID:
1463        if (Stream.ReadBlockInfoBlock())
1464          return Error("Malformed BlockInfoBlock");
1465        break;
1466      case bitc::PARAMATTR_BLOCK_ID:
1467        if (ParseAttributeBlock())
1468          return true;
1469        break;
1470      case bitc::TYPE_BLOCK_ID_NEW:
1471        if (ParseTypeTable())
1472          return true;
1473        break;
1474      case bitc::VALUE_SYMTAB_BLOCK_ID:
1475        if (ParseValueSymbolTable())
1476          return true;
1477        SeenValueSymbolTable = true;
1478        break;
1479      case bitc::CONSTANTS_BLOCK_ID:
1480        if (ParseConstants() || ResolveGlobalAndAliasInits())
1481          return true;
1482        break;
1483      case bitc::METADATA_BLOCK_ID:
1484        if (ParseMetadata())
1485          return true;
1486        break;
1487      case bitc::FUNCTION_BLOCK_ID:
1488        // If this is the first function body we've seen, reverse the
1489        // FunctionsWithBodies list.
1490        if (!SeenFirstFunctionBody) {
1491          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
1492          if (GlobalCleanup())
1493            return true;
1494          SeenFirstFunctionBody = true;
1495        }
1496
1497        if (RememberAndSkipFunctionBody())
1498          return true;
1499        // For streaming bitcode, suspend parsing when we reach the function
1500        // bodies. Subsequent materialization calls will resume it when
1501        // necessary. For streaming, the function bodies must be at the end of
1502        // the bitcode. If the bitcode file is old, the symbol table will be
1503        // at the end instead and will not have been seen yet. In this case,
1504        // just finish the parse now.
1505        if (LazyStreamer && SeenValueSymbolTable) {
1506          NextUnreadBit = Stream.GetCurrentBitNo();
1507          return false;
1508        }
1509        break;
1510      case bitc::USELIST_BLOCK_ID:
1511        if (ParseUseLists())
1512          return true;
1513        break;
1514      }
1515      continue;
1516    }
1517
1518    if (Code == bitc::DEFINE_ABBREV) {
1519      Stream.ReadAbbrevRecord();
1520      continue;
1521    }
1522
1523    // Read a record.
1524    switch (Stream.ReadRecord(Code, Record)) {
1525    default: break;  // Default behavior, ignore unknown content.
1526    case bitc::MODULE_CODE_VERSION: {  // VERSION: [version#]
1527      if (Record.size() < 1)
1528        return Error("Malformed MODULE_CODE_VERSION");
1529      // Only version #0 and #1 are supported so far.
1530      unsigned module_version = Record[0];
1531      switch (module_version) {
1532        default: return Error("Unknown bitstream version!");
1533        case 0:
1534          UseRelativeIDs = false;
1535          break;
1536        case 1:
1537          UseRelativeIDs = true;
1538          break;
1539      }
1540      break;
1541    }
1542    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1543      std::string S;
1544      if (ConvertToString(Record, 0, S))
1545        return Error("Invalid MODULE_CODE_TRIPLE record");
1546      TheModule->setTargetTriple(S);
1547      break;
1548    }
1549    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
1550      std::string S;
1551      if (ConvertToString(Record, 0, S))
1552        return Error("Invalid MODULE_CODE_DATALAYOUT record");
1553      TheModule->setDataLayout(S);
1554      break;
1555    }
1556    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
1557      std::string S;
1558      if (ConvertToString(Record, 0, S))
1559        return Error("Invalid MODULE_CODE_ASM record");
1560      TheModule->setModuleInlineAsm(S);
1561      break;
1562    }
1563    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
1564      std::string S;
1565      if (ConvertToString(Record, 0, S))
1566        return Error("Invalid MODULE_CODE_DEPLIB record");
1567      TheModule->addLibrary(S);
1568      break;
1569    }
1570    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
1571      std::string S;
1572      if (ConvertToString(Record, 0, S))
1573        return Error("Invalid MODULE_CODE_SECTIONNAME record");
1574      SectionTable.push_back(S);
1575      break;
1576    }
1577    case bitc::MODULE_CODE_GCNAME: {  // SECTIONNAME: [strchr x N]
1578      std::string S;
1579      if (ConvertToString(Record, 0, S))
1580        return Error("Invalid MODULE_CODE_GCNAME record");
1581      GCTable.push_back(S);
1582      break;
1583    }
1584    // GLOBALVAR: [pointer type, isconst, initid,
1585    //             linkage, alignment, section, visibility, threadlocal,
1586    //             unnamed_addr]
1587    case bitc::MODULE_CODE_GLOBALVAR: {
1588      if (Record.size() < 6)
1589        return Error("Invalid MODULE_CODE_GLOBALVAR record");
1590      Type *Ty = getTypeByID(Record[0]);
1591      if (!Ty) return Error("Invalid MODULE_CODE_GLOBALVAR record");
1592      if (!Ty->isPointerTy())
1593        return Error("Global not a pointer type!");
1594      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
1595      Ty = cast<PointerType>(Ty)->getElementType();
1596
1597      bool isConstant = Record[1];
1598      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1599      unsigned Alignment = (1 << Record[4]) >> 1;
1600      std::string Section;
1601      if (Record[5]) {
1602        if (Record[5]-1 >= SectionTable.size())
1603          return Error("Invalid section ID");
1604        Section = SectionTable[Record[5]-1];
1605      }
1606      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1607      if (Record.size() > 6)
1608        Visibility = GetDecodedVisibility(Record[6]);
1609
1610      GlobalVariable::ThreadLocalMode TLM = GlobalVariable::NotThreadLocal;
1611      if (Record.size() > 7)
1612        TLM = GetDecodedThreadLocalMode(Record[7]);
1613
1614      bool UnnamedAddr = false;
1615      if (Record.size() > 8)
1616        UnnamedAddr = Record[8];
1617
1618      GlobalVariable *NewGV =
1619        new GlobalVariable(*TheModule, Ty, isConstant, Linkage, 0, "", 0,
1620                           TLM, AddressSpace);
1621      NewGV->setAlignment(Alignment);
1622      if (!Section.empty())
1623        NewGV->setSection(Section);
1624      NewGV->setVisibility(Visibility);
1625      NewGV->setUnnamedAddr(UnnamedAddr);
1626
1627      ValueList.push_back(NewGV);
1628
1629      // Remember which value to use for the global initializer.
1630      if (unsigned InitID = Record[2])
1631        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1632      break;
1633    }
1634    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1635    //             alignment, section, visibility, gc, unnamed_addr]
1636    case bitc::MODULE_CODE_FUNCTION: {
1637      if (Record.size() < 8)
1638        return Error("Invalid MODULE_CODE_FUNCTION record");
1639      Type *Ty = getTypeByID(Record[0]);
1640      if (!Ty) return Error("Invalid MODULE_CODE_FUNCTION record");
1641      if (!Ty->isPointerTy())
1642        return Error("Function not a pointer type!");
1643      FunctionType *FTy =
1644        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1645      if (!FTy)
1646        return Error("Function not a pointer to function type!");
1647
1648      Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
1649                                        "", TheModule);
1650
1651      Func->setCallingConv(static_cast<CallingConv::ID>(Record[1]));
1652      bool isProto = Record[2];
1653      Func->setLinkage(GetDecodedLinkage(Record[3]));
1654      Func->setAttributes(getAttributes(Record[4]));
1655
1656      Func->setAlignment((1 << Record[5]) >> 1);
1657      if (Record[6]) {
1658        if (Record[6]-1 >= SectionTable.size())
1659          return Error("Invalid section ID");
1660        Func->setSection(SectionTable[Record[6]-1]);
1661      }
1662      Func->setVisibility(GetDecodedVisibility(Record[7]));
1663      if (Record.size() > 8 && Record[8]) {
1664        if (Record[8]-1 > GCTable.size())
1665          return Error("Invalid GC ID");
1666        Func->setGC(GCTable[Record[8]-1].c_str());
1667      }
1668      bool UnnamedAddr = false;
1669      if (Record.size() > 9)
1670        UnnamedAddr = Record[9];
1671      Func->setUnnamedAddr(UnnamedAddr);
1672      ValueList.push_back(Func);
1673
1674      // If this is a function with a body, remember the prototype we are
1675      // creating now, so that we can match up the body with them later.
1676      if (!isProto) {
1677        FunctionsWithBodies.push_back(Func);
1678        if (LazyStreamer) DeferredFunctionInfo[Func] = 0;
1679      }
1680      break;
1681    }
1682    // ALIAS: [alias type, aliasee val#, linkage]
1683    // ALIAS: [alias type, aliasee val#, linkage, visibility]
1684    case bitc::MODULE_CODE_ALIAS: {
1685      if (Record.size() < 3)
1686        return Error("Invalid MODULE_ALIAS record");
1687      Type *Ty = getTypeByID(Record[0]);
1688      if (!Ty) return Error("Invalid MODULE_ALIAS record");
1689      if (!Ty->isPointerTy())
1690        return Error("Function not a pointer type!");
1691
1692      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1693                                           "", 0, TheModule);
1694      // Old bitcode files didn't have visibility field.
1695      if (Record.size() > 3)
1696        NewGA->setVisibility(GetDecodedVisibility(Record[3]));
1697      ValueList.push_back(NewGA);
1698      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1699      break;
1700    }
1701    /// MODULE_CODE_PURGEVALS: [numvals]
1702    case bitc::MODULE_CODE_PURGEVALS:
1703      // Trim down the value list to the specified size.
1704      if (Record.size() < 1 || Record[0] > ValueList.size())
1705        return Error("Invalid MODULE_PURGEVALS record");
1706      ValueList.shrinkTo(Record[0]);
1707      break;
1708    }
1709    Record.clear();
1710  }
1711
1712  return Error("Premature end of bitstream");
1713}
1714
1715bool BitcodeReader::ParseBitcodeInto(Module *M) {
1716  TheModule = 0;
1717
1718  if (InitStream()) return true;
1719
1720  // Sniff for the signature.
1721  if (Stream.Read(8) != 'B' ||
1722      Stream.Read(8) != 'C' ||
1723      Stream.Read(4) != 0x0 ||
1724      Stream.Read(4) != 0xC ||
1725      Stream.Read(4) != 0xE ||
1726      Stream.Read(4) != 0xD)
1727    return Error("Invalid bitcode signature");
1728
1729  // We expect a number of well-defined blocks, though we don't necessarily
1730  // need to understand them all.
1731  while (!Stream.AtEndOfStream()) {
1732    unsigned Code = Stream.ReadCode();
1733
1734    if (Code != bitc::ENTER_SUBBLOCK) {
1735
1736      // The ranlib in xcode 4 will align archive members by appending newlines
1737      // to the end of them. If this file size is a multiple of 4 but not 8, we
1738      // have to read and ignore these final 4 bytes :-(
1739      if (Stream.GetAbbrevIDWidth() == 2 && Code == 2 &&
1740          Stream.Read(6) == 2 && Stream.Read(24) == 0xa0a0a &&
1741          Stream.AtEndOfStream())
1742        return false;
1743
1744      return Error("Invalid record at top-level");
1745    }
1746
1747    unsigned BlockID = Stream.ReadSubBlockID();
1748
1749    // We only know the MODULE subblock ID.
1750    switch (BlockID) {
1751    case bitc::BLOCKINFO_BLOCK_ID:
1752      if (Stream.ReadBlockInfoBlock())
1753        return Error("Malformed BlockInfoBlock");
1754      break;
1755    case bitc::MODULE_BLOCK_ID:
1756      // Reject multiple MODULE_BLOCK's in a single bitstream.
1757      if (TheModule)
1758        return Error("Multiple MODULE_BLOCKs in same stream");
1759      TheModule = M;
1760      if (ParseModule(false))
1761        return true;
1762      if (LazyStreamer) return false;
1763      break;
1764    default:
1765      if (Stream.SkipBlock())
1766        return Error("Malformed block record");
1767      break;
1768    }
1769  }
1770
1771  return false;
1772}
1773
1774bool BitcodeReader::ParseModuleTriple(std::string &Triple) {
1775  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
1776    return Error("Malformed block record");
1777
1778  SmallVector<uint64_t, 64> Record;
1779
1780  // Read all the records for this module.
1781  while (!Stream.AtEndOfStream()) {
1782    unsigned Code = Stream.ReadCode();
1783    if (Code == bitc::END_BLOCK) {
1784      if (Stream.ReadBlockEnd())
1785        return Error("Error at end of module block");
1786
1787      return false;
1788    }
1789
1790    if (Code == bitc::ENTER_SUBBLOCK) {
1791      switch (Stream.ReadSubBlockID()) {
1792      default:  // Skip unknown content.
1793        if (Stream.SkipBlock())
1794          return Error("Malformed block record");
1795        break;
1796      }
1797      continue;
1798    }
1799
1800    if (Code == bitc::DEFINE_ABBREV) {
1801      Stream.ReadAbbrevRecord();
1802      continue;
1803    }
1804
1805    // Read a record.
1806    switch (Stream.ReadRecord(Code, Record)) {
1807    default: break;  // Default behavior, ignore unknown content.
1808    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1809      std::string S;
1810      if (ConvertToString(Record, 0, S))
1811        return Error("Invalid MODULE_CODE_TRIPLE record");
1812      Triple = S;
1813      break;
1814    }
1815    }
1816    Record.clear();
1817  }
1818
1819  return Error("Premature end of bitstream");
1820}
1821
1822bool BitcodeReader::ParseTriple(std::string &Triple) {
1823  if (InitStream()) return true;
1824
1825  // Sniff for the signature.
1826  if (Stream.Read(8) != 'B' ||
1827      Stream.Read(8) != 'C' ||
1828      Stream.Read(4) != 0x0 ||
1829      Stream.Read(4) != 0xC ||
1830      Stream.Read(4) != 0xE ||
1831      Stream.Read(4) != 0xD)
1832    return Error("Invalid bitcode signature");
1833
1834  // We expect a number of well-defined blocks, though we don't necessarily
1835  // need to understand them all.
1836  while (!Stream.AtEndOfStream()) {
1837    unsigned Code = Stream.ReadCode();
1838
1839    if (Code != bitc::ENTER_SUBBLOCK)
1840      return Error("Invalid record at top-level");
1841
1842    unsigned BlockID = Stream.ReadSubBlockID();
1843
1844    // We only know the MODULE subblock ID.
1845    switch (BlockID) {
1846    case bitc::MODULE_BLOCK_ID:
1847      if (ParseModuleTriple(Triple))
1848        return true;
1849      break;
1850    default:
1851      if (Stream.SkipBlock())
1852        return Error("Malformed block record");
1853      break;
1854    }
1855  }
1856
1857  return false;
1858}
1859
1860/// ParseMetadataAttachment - Parse metadata attachments.
1861bool BitcodeReader::ParseMetadataAttachment() {
1862  if (Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
1863    return Error("Malformed block record");
1864
1865  SmallVector<uint64_t, 64> Record;
1866  while(1) {
1867    unsigned Code = Stream.ReadCode();
1868    if (Code == bitc::END_BLOCK) {
1869      if (Stream.ReadBlockEnd())
1870        return Error("Error at end of PARAMATTR block");
1871      break;
1872    }
1873    if (Code == bitc::DEFINE_ABBREV) {
1874      Stream.ReadAbbrevRecord();
1875      continue;
1876    }
1877    // Read a metadata attachment record.
1878    Record.clear();
1879    switch (Stream.ReadRecord(Code, Record)) {
1880    default:  // Default behavior: ignore.
1881      break;
1882    case bitc::METADATA_ATTACHMENT: {
1883      unsigned RecordLength = Record.size();
1884      if (Record.empty() || (RecordLength - 1) % 2 == 1)
1885        return Error ("Invalid METADATA_ATTACHMENT reader!");
1886      Instruction *Inst = InstructionList[Record[0]];
1887      for (unsigned i = 1; i != RecordLength; i = i+2) {
1888        unsigned Kind = Record[i];
1889        DenseMap<unsigned, unsigned>::iterator I =
1890          MDKindMap.find(Kind);
1891        if (I == MDKindMap.end())
1892          return Error("Invalid metadata kind ID");
1893        Value *Node = MDValueList.getValueFwdRef(Record[i+1]);
1894        Inst->setMetadata(I->second, cast<MDNode>(Node));
1895      }
1896      break;
1897    }
1898    }
1899  }
1900  return false;
1901}
1902
1903/// ParseFunctionBody - Lazily parse the specified function body block.
1904bool BitcodeReader::ParseFunctionBody(Function *F) {
1905  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1906    return Error("Malformed block record");
1907
1908  InstructionList.clear();
1909  unsigned ModuleValueListSize = ValueList.size();
1910  unsigned ModuleMDValueListSize = MDValueList.size();
1911
1912  // Add all the function arguments to the value table.
1913  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1914    ValueList.push_back(I);
1915
1916  unsigned NextValueNo = ValueList.size();
1917  BasicBlock *CurBB = 0;
1918  unsigned CurBBNo = 0;
1919
1920  DebugLoc LastLoc;
1921
1922  // Read all the records.
1923  SmallVector<uint64_t, 64> Record;
1924  while (1) {
1925    unsigned Code = Stream.ReadCode();
1926    if (Code == bitc::END_BLOCK) {
1927      if (Stream.ReadBlockEnd())
1928        return Error("Error at end of function block");
1929      break;
1930    }
1931
1932    if (Code == bitc::ENTER_SUBBLOCK) {
1933      switch (Stream.ReadSubBlockID()) {
1934      default:  // Skip unknown content.
1935        if (Stream.SkipBlock())
1936          return Error("Malformed block record");
1937        break;
1938      case bitc::CONSTANTS_BLOCK_ID:
1939        if (ParseConstants()) return true;
1940        NextValueNo = ValueList.size();
1941        break;
1942      case bitc::VALUE_SYMTAB_BLOCK_ID:
1943        if (ParseValueSymbolTable()) return true;
1944        break;
1945      case bitc::METADATA_ATTACHMENT_ID:
1946        if (ParseMetadataAttachment()) return true;
1947        break;
1948      case bitc::METADATA_BLOCK_ID:
1949        if (ParseMetadata()) return true;
1950        break;
1951      }
1952      continue;
1953    }
1954
1955    if (Code == bitc::DEFINE_ABBREV) {
1956      Stream.ReadAbbrevRecord();
1957      continue;
1958    }
1959
1960    // Read a record.
1961    Record.clear();
1962    Instruction *I = 0;
1963    unsigned BitCode = Stream.ReadRecord(Code, Record);
1964    switch (BitCode) {
1965    default: // Default behavior: reject
1966      return Error("Unknown instruction");
1967    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1968      if (Record.size() < 1 || Record[0] == 0)
1969        return Error("Invalid DECLAREBLOCKS record");
1970      // Create all the basic blocks for the function.
1971      FunctionBBs.resize(Record[0]);
1972      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1973        FunctionBBs[i] = BasicBlock::Create(Context, "", F);
1974      CurBB = FunctionBBs[0];
1975      continue;
1976
1977    case bitc::FUNC_CODE_DEBUG_LOC_AGAIN:  // DEBUG_LOC_AGAIN
1978      // This record indicates that the last instruction is at the same
1979      // location as the previous instruction with a location.
1980      I = 0;
1981
1982      // Get the last instruction emitted.
1983      if (CurBB && !CurBB->empty())
1984        I = &CurBB->back();
1985      else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
1986               !FunctionBBs[CurBBNo-1]->empty())
1987        I = &FunctionBBs[CurBBNo-1]->back();
1988
1989      if (I == 0) return Error("Invalid DEBUG_LOC_AGAIN record");
1990      I->setDebugLoc(LastLoc);
1991      I = 0;
1992      continue;
1993
1994    case bitc::FUNC_CODE_DEBUG_LOC: {      // DEBUG_LOC: [line, col, scope, ia]
1995      I = 0;     // Get the last instruction emitted.
1996      if (CurBB && !CurBB->empty())
1997        I = &CurBB->back();
1998      else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
1999               !FunctionBBs[CurBBNo-1]->empty())
2000        I = &FunctionBBs[CurBBNo-1]->back();
2001      if (I == 0 || Record.size() < 4)
2002        return Error("Invalid FUNC_CODE_DEBUG_LOC record");
2003
2004      unsigned Line = Record[0], Col = Record[1];
2005      unsigned ScopeID = Record[2], IAID = Record[3];
2006
2007      MDNode *Scope = 0, *IA = 0;
2008      if (ScopeID) Scope = cast<MDNode>(MDValueList.getValueFwdRef(ScopeID-1));
2009      if (IAID)    IA = cast<MDNode>(MDValueList.getValueFwdRef(IAID-1));
2010      LastLoc = DebugLoc::get(Line, Col, Scope, IA);
2011      I->setDebugLoc(LastLoc);
2012      I = 0;
2013      continue;
2014    }
2015
2016    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
2017      unsigned OpNum = 0;
2018      Value *LHS, *RHS;
2019      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
2020          popValue(Record, OpNum, NextValueNo, LHS->getType(), RHS) ||
2021          OpNum+1 > Record.size())
2022        return Error("Invalid BINOP record");
2023
2024      int Opc = GetDecodedBinaryOpcode(Record[OpNum++], LHS->getType());
2025      if (Opc == -1) return Error("Invalid BINOP record");
2026      I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
2027      InstructionList.push_back(I);
2028      if (OpNum < Record.size()) {
2029        if (Opc == Instruction::Add ||
2030            Opc == Instruction::Sub ||
2031            Opc == Instruction::Mul ||
2032            Opc == Instruction::Shl) {
2033          if (Record[OpNum] & (1 << bitc::OBO_NO_SIGNED_WRAP))
2034            cast<BinaryOperator>(I)->setHasNoSignedWrap(true);
2035          if (Record[OpNum] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
2036            cast<BinaryOperator>(I)->setHasNoUnsignedWrap(true);
2037        } else if (Opc == Instruction::SDiv ||
2038                   Opc == Instruction::UDiv ||
2039                   Opc == Instruction::LShr ||
2040                   Opc == Instruction::AShr) {
2041          if (Record[OpNum] & (1 << bitc::PEO_EXACT))
2042            cast<BinaryOperator>(I)->setIsExact(true);
2043        }
2044      }
2045      break;
2046    }
2047    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
2048      unsigned OpNum = 0;
2049      Value *Op;
2050      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2051          OpNum+2 != Record.size())
2052        return Error("Invalid CAST record");
2053
2054      Type *ResTy = getTypeByID(Record[OpNum]);
2055      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
2056      if (Opc == -1 || ResTy == 0)
2057        return Error("Invalid CAST record");
2058      I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
2059      InstructionList.push_back(I);
2060      break;
2061    }
2062    case bitc::FUNC_CODE_INST_INBOUNDS_GEP:
2063    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
2064      unsigned OpNum = 0;
2065      Value *BasePtr;
2066      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
2067        return Error("Invalid GEP record");
2068
2069      SmallVector<Value*, 16> GEPIdx;
2070      while (OpNum != Record.size()) {
2071        Value *Op;
2072        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2073          return Error("Invalid GEP record");
2074        GEPIdx.push_back(Op);
2075      }
2076
2077      I = GetElementPtrInst::Create(BasePtr, GEPIdx);
2078      InstructionList.push_back(I);
2079      if (BitCode == bitc::FUNC_CODE_INST_INBOUNDS_GEP)
2080        cast<GetElementPtrInst>(I)->setIsInBounds(true);
2081      break;
2082    }
2083
2084    case bitc::FUNC_CODE_INST_EXTRACTVAL: {
2085                                       // EXTRACTVAL: [opty, opval, n x indices]
2086      unsigned OpNum = 0;
2087      Value *Agg;
2088      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2089        return Error("Invalid EXTRACTVAL record");
2090
2091      SmallVector<unsigned, 4> EXTRACTVALIdx;
2092      for (unsigned RecSize = Record.size();
2093           OpNum != RecSize; ++OpNum) {
2094        uint64_t Index = Record[OpNum];
2095        if ((unsigned)Index != Index)
2096          return Error("Invalid EXTRACTVAL index");
2097        EXTRACTVALIdx.push_back((unsigned)Index);
2098      }
2099
2100      I = ExtractValueInst::Create(Agg, EXTRACTVALIdx);
2101      InstructionList.push_back(I);
2102      break;
2103    }
2104
2105    case bitc::FUNC_CODE_INST_INSERTVAL: {
2106                           // INSERTVAL: [opty, opval, opty, opval, n x indices]
2107      unsigned OpNum = 0;
2108      Value *Agg;
2109      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2110        return Error("Invalid INSERTVAL record");
2111      Value *Val;
2112      if (getValueTypePair(Record, OpNum, NextValueNo, Val))
2113        return Error("Invalid INSERTVAL record");
2114
2115      SmallVector<unsigned, 4> INSERTVALIdx;
2116      for (unsigned RecSize = Record.size();
2117           OpNum != RecSize; ++OpNum) {
2118        uint64_t Index = Record[OpNum];
2119        if ((unsigned)Index != Index)
2120          return Error("Invalid INSERTVAL index");
2121        INSERTVALIdx.push_back((unsigned)Index);
2122      }
2123
2124      I = InsertValueInst::Create(Agg, Val, INSERTVALIdx);
2125      InstructionList.push_back(I);
2126      break;
2127    }
2128
2129    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
2130      // obsolete form of select
2131      // handles select i1 ... in old bitcode
2132      unsigned OpNum = 0;
2133      Value *TrueVal, *FalseVal, *Cond;
2134      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2135          popValue(Record, OpNum, NextValueNo, TrueVal->getType(), FalseVal) ||
2136          popValue(Record, OpNum, NextValueNo, Type::getInt1Ty(Context), Cond))
2137        return Error("Invalid SELECT record");
2138
2139      I = SelectInst::Create(Cond, TrueVal, FalseVal);
2140      InstructionList.push_back(I);
2141      break;
2142    }
2143
2144    case bitc::FUNC_CODE_INST_VSELECT: {// VSELECT: [ty,opval,opval,predty,pred]
2145      // new form of select
2146      // handles select i1 or select [N x i1]
2147      unsigned OpNum = 0;
2148      Value *TrueVal, *FalseVal, *Cond;
2149      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2150          popValue(Record, OpNum, NextValueNo, TrueVal->getType(), FalseVal) ||
2151          getValueTypePair(Record, OpNum, NextValueNo, Cond))
2152        return Error("Invalid SELECT record");
2153
2154      // select condition can be either i1 or [N x i1]
2155      if (VectorType* vector_type =
2156          dyn_cast<VectorType>(Cond->getType())) {
2157        // expect <n x i1>
2158        if (vector_type->getElementType() != Type::getInt1Ty(Context))
2159          return Error("Invalid SELECT condition type");
2160      } else {
2161        // expect i1
2162        if (Cond->getType() != Type::getInt1Ty(Context))
2163          return Error("Invalid SELECT condition type");
2164      }
2165
2166      I = SelectInst::Create(Cond, TrueVal, FalseVal);
2167      InstructionList.push_back(I);
2168      break;
2169    }
2170
2171    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
2172      unsigned OpNum = 0;
2173      Value *Vec, *Idx;
2174      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2175          popValue(Record, OpNum, NextValueNo, Type::getInt32Ty(Context), Idx))
2176        return Error("Invalid EXTRACTELT record");
2177      I = ExtractElementInst::Create(Vec, Idx);
2178      InstructionList.push_back(I);
2179      break;
2180    }
2181
2182    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
2183      unsigned OpNum = 0;
2184      Value *Vec, *Elt, *Idx;
2185      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2186          popValue(Record, OpNum, NextValueNo,
2187                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
2188          popValue(Record, OpNum, NextValueNo, Type::getInt32Ty(Context), Idx))
2189        return Error("Invalid INSERTELT record");
2190      I = InsertElementInst::Create(Vec, Elt, Idx);
2191      InstructionList.push_back(I);
2192      break;
2193    }
2194
2195    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
2196      unsigned OpNum = 0;
2197      Value *Vec1, *Vec2, *Mask;
2198      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
2199          popValue(Record, OpNum, NextValueNo, Vec1->getType(), Vec2))
2200        return Error("Invalid SHUFFLEVEC record");
2201
2202      if (getValueTypePair(Record, OpNum, NextValueNo, Mask))
2203        return Error("Invalid SHUFFLEVEC record");
2204      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
2205      InstructionList.push_back(I);
2206      break;
2207    }
2208
2209    case bitc::FUNC_CODE_INST_CMP:   // CMP: [opty, opval, opval, pred]
2210      // Old form of ICmp/FCmp returning bool
2211      // Existed to differentiate between icmp/fcmp and vicmp/vfcmp which were
2212      // both legal on vectors but had different behaviour.
2213    case bitc::FUNC_CODE_INST_CMP2: { // CMP2: [opty, opval, opval, pred]
2214      // FCmp/ICmp returning bool or vector of bool
2215
2216      unsigned OpNum = 0;
2217      Value *LHS, *RHS;
2218      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
2219          popValue(Record, OpNum, NextValueNo, LHS->getType(), RHS) ||
2220          OpNum+1 != Record.size())
2221        return Error("Invalid CMP record");
2222
2223      if (LHS->getType()->isFPOrFPVectorTy())
2224        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
2225      else
2226        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
2227      InstructionList.push_back(I);
2228      break;
2229    }
2230
2231    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
2232      {
2233        unsigned Size = Record.size();
2234        if (Size == 0) {
2235          I = ReturnInst::Create(Context);
2236          InstructionList.push_back(I);
2237          break;
2238        }
2239
2240        unsigned OpNum = 0;
2241        Value *Op = NULL;
2242        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2243          return Error("Invalid RET record");
2244        if (OpNum != Record.size())
2245          return Error("Invalid RET record");
2246
2247        I = ReturnInst::Create(Context, Op);
2248        InstructionList.push_back(I);
2249        break;
2250      }
2251    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
2252      if (Record.size() != 1 && Record.size() != 3)
2253        return Error("Invalid BR record");
2254      BasicBlock *TrueDest = getBasicBlock(Record[0]);
2255      if (TrueDest == 0)
2256        return Error("Invalid BR record");
2257
2258      if (Record.size() == 1) {
2259        I = BranchInst::Create(TrueDest);
2260        InstructionList.push_back(I);
2261      }
2262      else {
2263        BasicBlock *FalseDest = getBasicBlock(Record[1]);
2264        Value *Cond = getValue(Record, 2, NextValueNo,
2265                               Type::getInt1Ty(Context));
2266        if (FalseDest == 0 || Cond == 0)
2267          return Error("Invalid BR record");
2268        I = BranchInst::Create(TrueDest, FalseDest, Cond);
2269        InstructionList.push_back(I);
2270      }
2271      break;
2272    }
2273    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, op0, op1, ...]
2274      // Check magic
2275      if ((Record[0] >> 16) == SWITCH_INST_MAGIC) {
2276        // New SwitchInst format with case ranges.
2277
2278        Type *OpTy = getTypeByID(Record[1]);
2279        unsigned ValueBitWidth = cast<IntegerType>(OpTy)->getBitWidth();
2280
2281        Value *Cond = getValue(Record, 2, NextValueNo, OpTy);
2282        BasicBlock *Default = getBasicBlock(Record[3]);
2283        if (OpTy == 0 || Cond == 0 || Default == 0)
2284          return Error("Invalid SWITCH record");
2285
2286        unsigned NumCases = Record[4];
2287
2288        SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
2289        InstructionList.push_back(SI);
2290
2291        unsigned CurIdx = 5;
2292        for (unsigned i = 0; i != NumCases; ++i) {
2293          IntegersSubsetToBB CaseBuilder;
2294          unsigned NumItems = Record[CurIdx++];
2295          for (unsigned ci = 0; ci != NumItems; ++ci) {
2296            bool isSingleNumber = Record[CurIdx++];
2297
2298            APInt Low;
2299            unsigned ActiveWords = 1;
2300            if (ValueBitWidth > 64)
2301              ActiveWords = Record[CurIdx++];
2302            Low = ReadWideAPInt(makeArrayRef(&Record[CurIdx], ActiveWords),
2303                                ValueBitWidth);
2304            CurIdx += ActiveWords;
2305
2306            if (!isSingleNumber) {
2307              ActiveWords = 1;
2308              if (ValueBitWidth > 64)
2309                ActiveWords = Record[CurIdx++];
2310              APInt High =
2311                  ReadWideAPInt(makeArrayRef(&Record[CurIdx], ActiveWords),
2312                                ValueBitWidth);
2313
2314              CaseBuilder.add(IntItem::fromType(OpTy, Low),
2315                              IntItem::fromType(OpTy, High));
2316              CurIdx += ActiveWords;
2317            } else
2318              CaseBuilder.add(IntItem::fromType(OpTy, Low));
2319          }
2320          BasicBlock *DestBB = getBasicBlock(Record[CurIdx++]);
2321          IntegersSubset Case = CaseBuilder.getCase();
2322          SI->addCase(Case, DestBB);
2323        }
2324        uint16_t Hash = SI->hash();
2325        if (Hash != (Record[0] & 0xFFFF))
2326          return Error("Invalid SWITCH record");
2327        I = SI;
2328        break;
2329      }
2330
2331      // Old SwitchInst format without case ranges.
2332
2333      if (Record.size() < 3 || (Record.size() & 1) == 0)
2334        return Error("Invalid SWITCH record");
2335      Type *OpTy = getTypeByID(Record[0]);
2336      Value *Cond = getValue(Record, 1, NextValueNo, OpTy);
2337      BasicBlock *Default = getBasicBlock(Record[2]);
2338      if (OpTy == 0 || Cond == 0 || Default == 0)
2339        return Error("Invalid SWITCH record");
2340      unsigned NumCases = (Record.size()-3)/2;
2341      SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
2342      InstructionList.push_back(SI);
2343      for (unsigned i = 0, e = NumCases; i != e; ++i) {
2344        ConstantInt *CaseVal =
2345          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
2346        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
2347        if (CaseVal == 0 || DestBB == 0) {
2348          delete SI;
2349          return Error("Invalid SWITCH record!");
2350        }
2351        SI->addCase(CaseVal, DestBB);
2352      }
2353      I = SI;
2354      break;
2355    }
2356    case bitc::FUNC_CODE_INST_INDIRECTBR: { // INDIRECTBR: [opty, op0, op1, ...]
2357      if (Record.size() < 2)
2358        return Error("Invalid INDIRECTBR record");
2359      Type *OpTy = getTypeByID(Record[0]);
2360      Value *Address = getValue(Record, 1, NextValueNo, OpTy);
2361      if (OpTy == 0 || Address == 0)
2362        return Error("Invalid INDIRECTBR record");
2363      unsigned NumDests = Record.size()-2;
2364      IndirectBrInst *IBI = IndirectBrInst::Create(Address, NumDests);
2365      InstructionList.push_back(IBI);
2366      for (unsigned i = 0, e = NumDests; i != e; ++i) {
2367        if (BasicBlock *DestBB = getBasicBlock(Record[2+i])) {
2368          IBI->addDestination(DestBB);
2369        } else {
2370          delete IBI;
2371          return Error("Invalid INDIRECTBR record!");
2372        }
2373      }
2374      I = IBI;
2375      break;
2376    }
2377
2378    case bitc::FUNC_CODE_INST_INVOKE: {
2379      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
2380      if (Record.size() < 4) return Error("Invalid INVOKE record");
2381      AttrListPtr PAL = getAttributes(Record[0]);
2382      unsigned CCInfo = Record[1];
2383      BasicBlock *NormalBB = getBasicBlock(Record[2]);
2384      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
2385
2386      unsigned OpNum = 4;
2387      Value *Callee;
2388      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
2389        return Error("Invalid INVOKE record");
2390
2391      PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
2392      FunctionType *FTy = !CalleeTy ? 0 :
2393        dyn_cast<FunctionType>(CalleeTy->getElementType());
2394
2395      // Check that the right number of fixed parameters are here.
2396      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
2397          Record.size() < OpNum+FTy->getNumParams())
2398        return Error("Invalid INVOKE record");
2399
2400      SmallVector<Value*, 16> Ops;
2401      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
2402        Ops.push_back(getValue(Record, OpNum, NextValueNo,
2403                               FTy->getParamType(i)));
2404        if (Ops.back() == 0) return Error("Invalid INVOKE record");
2405      }
2406
2407      if (!FTy->isVarArg()) {
2408        if (Record.size() != OpNum)
2409          return Error("Invalid INVOKE record");
2410      } else {
2411        // Read type/value pairs for varargs params.
2412        while (OpNum != Record.size()) {
2413          Value *Op;
2414          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2415            return Error("Invalid INVOKE record");
2416          Ops.push_back(Op);
2417        }
2418      }
2419
2420      I = InvokeInst::Create(Callee, NormalBB, UnwindBB, Ops);
2421      InstructionList.push_back(I);
2422      cast<InvokeInst>(I)->setCallingConv(
2423        static_cast<CallingConv::ID>(CCInfo));
2424      cast<InvokeInst>(I)->setAttributes(PAL);
2425      break;
2426    }
2427    case bitc::FUNC_CODE_INST_RESUME: { // RESUME: [opval]
2428      unsigned Idx = 0;
2429      Value *Val = 0;
2430      if (getValueTypePair(Record, Idx, NextValueNo, Val))
2431        return Error("Invalid RESUME record");
2432      I = ResumeInst::Create(Val);
2433      InstructionList.push_back(I);
2434      break;
2435    }
2436    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
2437      I = new UnreachableInst(Context);
2438      InstructionList.push_back(I);
2439      break;
2440    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
2441      if (Record.size() < 1 || ((Record.size()-1)&1))
2442        return Error("Invalid PHI record");
2443      Type *Ty = getTypeByID(Record[0]);
2444      if (!Ty) return Error("Invalid PHI record");
2445
2446      PHINode *PN = PHINode::Create(Ty, (Record.size()-1)/2);
2447      InstructionList.push_back(PN);
2448
2449      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
2450        Value *V;
2451        // With the new function encoding, it is possible that operands have
2452        // negative IDs (for forward references).  Use a signed VBR
2453        // representation to keep the encoding small.
2454        if (UseRelativeIDs)
2455          V = getValueSigned(Record, 1+i, NextValueNo, Ty);
2456        else
2457          V = getValue(Record, 1+i, NextValueNo, Ty);
2458        BasicBlock *BB = getBasicBlock(Record[2+i]);
2459        if (!V || !BB) return Error("Invalid PHI record");
2460        PN->addIncoming(V, BB);
2461      }
2462      I = PN;
2463      break;
2464    }
2465
2466    case bitc::FUNC_CODE_INST_LANDINGPAD: {
2467      // LANDINGPAD: [ty, val, val, num, (id0,val0 ...)?]
2468      unsigned Idx = 0;
2469      if (Record.size() < 4)
2470        return Error("Invalid LANDINGPAD record");
2471      Type *Ty = getTypeByID(Record[Idx++]);
2472      if (!Ty) return Error("Invalid LANDINGPAD record");
2473      Value *PersFn = 0;
2474      if (getValueTypePair(Record, Idx, NextValueNo, PersFn))
2475        return Error("Invalid LANDINGPAD record");
2476
2477      bool IsCleanup = !!Record[Idx++];
2478      unsigned NumClauses = Record[Idx++];
2479      LandingPadInst *LP = LandingPadInst::Create(Ty, PersFn, NumClauses);
2480      LP->setCleanup(IsCleanup);
2481      for (unsigned J = 0; J != NumClauses; ++J) {
2482        LandingPadInst::ClauseType CT =
2483          LandingPadInst::ClauseType(Record[Idx++]); (void)CT;
2484        Value *Val;
2485
2486        if (getValueTypePair(Record, Idx, NextValueNo, Val)) {
2487          delete LP;
2488          return Error("Invalid LANDINGPAD record");
2489        }
2490
2491        assert((CT != LandingPadInst::Catch ||
2492                !isa<ArrayType>(Val->getType())) &&
2493               "Catch clause has a invalid type!");
2494        assert((CT != LandingPadInst::Filter ||
2495                isa<ArrayType>(Val->getType())) &&
2496               "Filter clause has invalid type!");
2497        LP->addClause(Val);
2498      }
2499
2500      I = LP;
2501      InstructionList.push_back(I);
2502      break;
2503    }
2504
2505    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, opty, op, align]
2506      if (Record.size() != 4)
2507        return Error("Invalid ALLOCA record");
2508      PointerType *Ty =
2509        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
2510      Type *OpTy = getTypeByID(Record[1]);
2511      Value *Size = getFnValueByID(Record[2], OpTy);
2512      unsigned Align = Record[3];
2513      if (!Ty || !Size) return Error("Invalid ALLOCA record");
2514      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
2515      InstructionList.push_back(I);
2516      break;
2517    }
2518    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
2519      unsigned OpNum = 0;
2520      Value *Op;
2521      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2522          OpNum+2 != Record.size())
2523        return Error("Invalid LOAD record");
2524
2525      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
2526      InstructionList.push_back(I);
2527      break;
2528    }
2529    case bitc::FUNC_CODE_INST_LOADATOMIC: {
2530       // LOADATOMIC: [opty, op, align, vol, ordering, synchscope]
2531      unsigned OpNum = 0;
2532      Value *Op;
2533      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2534          OpNum+4 != Record.size())
2535        return Error("Invalid LOADATOMIC record");
2536
2537
2538      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2539      if (Ordering == NotAtomic || Ordering == Release ||
2540          Ordering == AcquireRelease)
2541        return Error("Invalid LOADATOMIC record");
2542      if (Ordering != NotAtomic && Record[OpNum] == 0)
2543        return Error("Invalid LOADATOMIC record");
2544      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2545
2546      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1,
2547                       Ordering, SynchScope);
2548      InstructionList.push_back(I);
2549      break;
2550    }
2551    case bitc::FUNC_CODE_INST_STORE: { // STORE2:[ptrty, ptr, val, align, vol]
2552      unsigned OpNum = 0;
2553      Value *Val, *Ptr;
2554      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2555          popValue(Record, OpNum, NextValueNo,
2556                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2557          OpNum+2 != Record.size())
2558        return Error("Invalid STORE record");
2559
2560      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
2561      InstructionList.push_back(I);
2562      break;
2563    }
2564    case bitc::FUNC_CODE_INST_STOREATOMIC: {
2565      // STOREATOMIC: [ptrty, ptr, val, align, vol, ordering, synchscope]
2566      unsigned OpNum = 0;
2567      Value *Val, *Ptr;
2568      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2569          popValue(Record, OpNum, NextValueNo,
2570                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2571          OpNum+4 != Record.size())
2572        return Error("Invalid STOREATOMIC record");
2573
2574      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2575      if (Ordering == NotAtomic || Ordering == Acquire ||
2576          Ordering == AcquireRelease)
2577        return Error("Invalid STOREATOMIC record");
2578      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2579      if (Ordering != NotAtomic && Record[OpNum] == 0)
2580        return Error("Invalid STOREATOMIC record");
2581
2582      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1,
2583                        Ordering, SynchScope);
2584      InstructionList.push_back(I);
2585      break;
2586    }
2587    case bitc::FUNC_CODE_INST_CMPXCHG: {
2588      // CMPXCHG:[ptrty, ptr, cmp, new, vol, ordering, synchscope]
2589      unsigned OpNum = 0;
2590      Value *Ptr, *Cmp, *New;
2591      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2592          popValue(Record, OpNum, NextValueNo,
2593                    cast<PointerType>(Ptr->getType())->getElementType(), Cmp) ||
2594          popValue(Record, OpNum, NextValueNo,
2595                    cast<PointerType>(Ptr->getType())->getElementType(), New) ||
2596          OpNum+3 != Record.size())
2597        return Error("Invalid CMPXCHG record");
2598      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+1]);
2599      if (Ordering == NotAtomic || Ordering == Unordered)
2600        return Error("Invalid CMPXCHG record");
2601      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+2]);
2602      I = new AtomicCmpXchgInst(Ptr, Cmp, New, Ordering, SynchScope);
2603      cast<AtomicCmpXchgInst>(I)->setVolatile(Record[OpNum]);
2604      InstructionList.push_back(I);
2605      break;
2606    }
2607    case bitc::FUNC_CODE_INST_ATOMICRMW: {
2608      // ATOMICRMW:[ptrty, ptr, val, op, vol, ordering, synchscope]
2609      unsigned OpNum = 0;
2610      Value *Ptr, *Val;
2611      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2612          popValue(Record, OpNum, NextValueNo,
2613                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2614          OpNum+4 != Record.size())
2615        return Error("Invalid ATOMICRMW record");
2616      AtomicRMWInst::BinOp Operation = GetDecodedRMWOperation(Record[OpNum]);
2617      if (Operation < AtomicRMWInst::FIRST_BINOP ||
2618          Operation > AtomicRMWInst::LAST_BINOP)
2619        return Error("Invalid ATOMICRMW record");
2620      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2621      if (Ordering == NotAtomic || Ordering == Unordered)
2622        return Error("Invalid ATOMICRMW record");
2623      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2624      I = new AtomicRMWInst(Operation, Ptr, Val, Ordering, SynchScope);
2625      cast<AtomicRMWInst>(I)->setVolatile(Record[OpNum+1]);
2626      InstructionList.push_back(I);
2627      break;
2628    }
2629    case bitc::FUNC_CODE_INST_FENCE: { // FENCE:[ordering, synchscope]
2630      if (2 != Record.size())
2631        return Error("Invalid FENCE record");
2632      AtomicOrdering Ordering = GetDecodedOrdering(Record[0]);
2633      if (Ordering == NotAtomic || Ordering == Unordered ||
2634          Ordering == Monotonic)
2635        return Error("Invalid FENCE record");
2636      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[1]);
2637      I = new FenceInst(Context, Ordering, SynchScope);
2638      InstructionList.push_back(I);
2639      break;
2640    }
2641    case bitc::FUNC_CODE_INST_CALL: {
2642      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
2643      if (Record.size() < 3)
2644        return Error("Invalid CALL record");
2645
2646      AttrListPtr PAL = getAttributes(Record[0]);
2647      unsigned CCInfo = Record[1];
2648
2649      unsigned OpNum = 2;
2650      Value *Callee;
2651      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
2652        return Error("Invalid CALL record");
2653
2654      PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
2655      FunctionType *FTy = 0;
2656      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
2657      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
2658        return Error("Invalid CALL record");
2659
2660      SmallVector<Value*, 16> Args;
2661      // Read the fixed params.
2662      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
2663        if (FTy->getParamType(i)->isLabelTy())
2664          Args.push_back(getBasicBlock(Record[OpNum]));
2665        else
2666          Args.push_back(getValue(Record, OpNum, NextValueNo,
2667                                  FTy->getParamType(i)));
2668        if (Args.back() == 0) return Error("Invalid CALL record");
2669      }
2670
2671      // Read type/value pairs for varargs params.
2672      if (!FTy->isVarArg()) {
2673        if (OpNum != Record.size())
2674          return Error("Invalid CALL record");
2675      } else {
2676        while (OpNum != Record.size()) {
2677          Value *Op;
2678          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2679            return Error("Invalid CALL record");
2680          Args.push_back(Op);
2681        }
2682      }
2683
2684      I = CallInst::Create(Callee, Args);
2685      InstructionList.push_back(I);
2686      cast<CallInst>(I)->setCallingConv(
2687        static_cast<CallingConv::ID>(CCInfo>>1));
2688      cast<CallInst>(I)->setTailCall(CCInfo & 1);
2689      cast<CallInst>(I)->setAttributes(PAL);
2690      break;
2691    }
2692    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
2693      if (Record.size() < 3)
2694        return Error("Invalid VAARG record");
2695      Type *OpTy = getTypeByID(Record[0]);
2696      Value *Op = getValue(Record, 1, NextValueNo, OpTy);
2697      Type *ResTy = getTypeByID(Record[2]);
2698      if (!OpTy || !Op || !ResTy)
2699        return Error("Invalid VAARG record");
2700      I = new VAArgInst(Op, ResTy);
2701      InstructionList.push_back(I);
2702      break;
2703    }
2704    }
2705
2706    // Add instruction to end of current BB.  If there is no current BB, reject
2707    // this file.
2708    if (CurBB == 0) {
2709      delete I;
2710      return Error("Invalid instruction with no BB");
2711    }
2712    CurBB->getInstList().push_back(I);
2713
2714    // If this was a terminator instruction, move to the next block.
2715    if (isa<TerminatorInst>(I)) {
2716      ++CurBBNo;
2717      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
2718    }
2719
2720    // Non-void values get registered in the value table for future use.
2721    if (I && !I->getType()->isVoidTy())
2722      ValueList.AssignValue(I, NextValueNo++);
2723  }
2724
2725  // Check the function list for unresolved values.
2726  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
2727    if (A->getParent() == 0) {
2728      // We found at least one unresolved value.  Nuke them all to avoid leaks.
2729      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
2730        if ((A = dyn_cast<Argument>(ValueList[i])) && A->getParent() == 0) {
2731          A->replaceAllUsesWith(UndefValue::get(A->getType()));
2732          delete A;
2733        }
2734      }
2735      return Error("Never resolved value found in function!");
2736    }
2737  }
2738
2739  // FIXME: Check for unresolved forward-declared metadata references
2740  // and clean up leaks.
2741
2742  // See if anything took the address of blocks in this function.  If so,
2743  // resolve them now.
2744  DenseMap<Function*, std::vector<BlockAddrRefTy> >::iterator BAFRI =
2745    BlockAddrFwdRefs.find(F);
2746  if (BAFRI != BlockAddrFwdRefs.end()) {
2747    std::vector<BlockAddrRefTy> &RefList = BAFRI->second;
2748    for (unsigned i = 0, e = RefList.size(); i != e; ++i) {
2749      unsigned BlockIdx = RefList[i].first;
2750      if (BlockIdx >= FunctionBBs.size())
2751        return Error("Invalid blockaddress block #");
2752
2753      GlobalVariable *FwdRef = RefList[i].second;
2754      FwdRef->replaceAllUsesWith(BlockAddress::get(F, FunctionBBs[BlockIdx]));
2755      FwdRef->eraseFromParent();
2756    }
2757
2758    BlockAddrFwdRefs.erase(BAFRI);
2759  }
2760
2761  // Trim the value list down to the size it was before we parsed this function.
2762  ValueList.shrinkTo(ModuleValueListSize);
2763  MDValueList.shrinkTo(ModuleMDValueListSize);
2764  std::vector<BasicBlock*>().swap(FunctionBBs);
2765  return false;
2766}
2767
2768/// FindFunctionInStream - Find the function body in the bitcode stream
2769bool BitcodeReader::FindFunctionInStream(Function *F,
2770       DenseMap<Function*, uint64_t>::iterator DeferredFunctionInfoIterator) {
2771  while (DeferredFunctionInfoIterator->second == 0) {
2772    if (Stream.AtEndOfStream())
2773      return Error("Could not find Function in stream");
2774    // ParseModule will parse the next body in the stream and set its
2775    // position in the DeferredFunctionInfo map.
2776    if (ParseModule(true)) return true;
2777  }
2778  return false;
2779}
2780
2781//===----------------------------------------------------------------------===//
2782// GVMaterializer implementation
2783//===----------------------------------------------------------------------===//
2784
2785
2786bool BitcodeReader::isMaterializable(const GlobalValue *GV) const {
2787  if (const Function *F = dyn_cast<Function>(GV)) {
2788    return F->isDeclaration() &&
2789      DeferredFunctionInfo.count(const_cast<Function*>(F));
2790  }
2791  return false;
2792}
2793
2794bool BitcodeReader::Materialize(GlobalValue *GV, std::string *ErrInfo) {
2795  Function *F = dyn_cast<Function>(GV);
2796  // If it's not a function or is already material, ignore the request.
2797  if (!F || !F->isMaterializable()) return false;
2798
2799  DenseMap<Function*, uint64_t>::iterator DFII = DeferredFunctionInfo.find(F);
2800  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
2801  // If its position is recorded as 0, its body is somewhere in the stream
2802  // but we haven't seen it yet.
2803  if (DFII->second == 0)
2804    if (LazyStreamer && FindFunctionInStream(F, DFII)) return true;
2805
2806  // Move the bit stream to the saved position of the deferred function body.
2807  Stream.JumpToBit(DFII->second);
2808
2809  if (ParseFunctionBody(F)) {
2810    if (ErrInfo) *ErrInfo = ErrorString;
2811    return true;
2812  }
2813
2814  // Upgrade any old intrinsic calls in the function.
2815  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
2816       E = UpgradedIntrinsics.end(); I != E; ++I) {
2817    if (I->first != I->second) {
2818      for (Value::use_iterator UI = I->first->use_begin(),
2819           UE = I->first->use_end(); UI != UE; ) {
2820        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2821          UpgradeIntrinsicCall(CI, I->second);
2822      }
2823    }
2824  }
2825
2826  return false;
2827}
2828
2829bool BitcodeReader::isDematerializable(const GlobalValue *GV) const {
2830  const Function *F = dyn_cast<Function>(GV);
2831  if (!F || F->isDeclaration())
2832    return false;
2833  return DeferredFunctionInfo.count(const_cast<Function*>(F));
2834}
2835
2836void BitcodeReader::Dematerialize(GlobalValue *GV) {
2837  Function *F = dyn_cast<Function>(GV);
2838  // If this function isn't dematerializable, this is a noop.
2839  if (!F || !isDematerializable(F))
2840    return;
2841
2842  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
2843
2844  // Just forget the function body, we can remat it later.
2845  F->deleteBody();
2846}
2847
2848
2849bool BitcodeReader::MaterializeModule(Module *M, std::string *ErrInfo) {
2850  assert(M == TheModule &&
2851         "Can only Materialize the Module this BitcodeReader is attached to.");
2852  // Iterate over the module, deserializing any functions that are still on
2853  // disk.
2854  for (Module::iterator F = TheModule->begin(), E = TheModule->end();
2855       F != E; ++F)
2856    if (F->isMaterializable() &&
2857        Materialize(F, ErrInfo))
2858      return true;
2859
2860  // At this point, if there are any function bodies, the current bit is
2861  // pointing to the END_BLOCK record after them. Now make sure the rest
2862  // of the bits in the module have been read.
2863  if (NextUnreadBit)
2864    ParseModule(true);
2865
2866  // Upgrade any intrinsic calls that slipped through (should not happen!) and
2867  // delete the old functions to clean up. We can't do this unless the entire
2868  // module is materialized because there could always be another function body
2869  // with calls to the old function.
2870  for (std::vector<std::pair<Function*, Function*> >::iterator I =
2871       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
2872    if (I->first != I->second) {
2873      for (Value::use_iterator UI = I->first->use_begin(),
2874           UE = I->first->use_end(); UI != UE; ) {
2875        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2876          UpgradeIntrinsicCall(CI, I->second);
2877      }
2878      if (!I->first->use_empty())
2879        I->first->replaceAllUsesWith(I->second);
2880      I->first->eraseFromParent();
2881    }
2882  }
2883  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
2884
2885  return false;
2886}
2887
2888bool BitcodeReader::InitStream() {
2889  if (LazyStreamer) return InitLazyStream();
2890  return InitStreamFromBuffer();
2891}
2892
2893bool BitcodeReader::InitStreamFromBuffer() {
2894  const unsigned char *BufPtr = (const unsigned char*)Buffer->getBufferStart();
2895  const unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
2896
2897  if (Buffer->getBufferSize() & 3) {
2898    if (!isRawBitcode(BufPtr, BufEnd) && !isBitcodeWrapper(BufPtr, BufEnd))
2899      return Error("Invalid bitcode signature");
2900    else
2901      return Error("Bitcode stream should be a multiple of 4 bytes in length");
2902  }
2903
2904  // If we have a wrapper header, parse it and ignore the non-bc file contents.
2905  // The magic number is 0x0B17C0DE stored in little endian.
2906  if (isBitcodeWrapper(BufPtr, BufEnd))
2907    if (SkipBitcodeWrapperHeader(BufPtr, BufEnd, true))
2908      return Error("Invalid bitcode wrapper header");
2909
2910  StreamFile.reset(new BitstreamReader(BufPtr, BufEnd));
2911  Stream.init(*StreamFile);
2912
2913  return false;
2914}
2915
2916bool BitcodeReader::InitLazyStream() {
2917  // Check and strip off the bitcode wrapper; BitstreamReader expects never to
2918  // see it.
2919  StreamingMemoryObject *Bytes = new StreamingMemoryObject(LazyStreamer);
2920  StreamFile.reset(new BitstreamReader(Bytes));
2921  Stream.init(*StreamFile);
2922
2923  unsigned char buf[16];
2924  if (Bytes->readBytes(0, 16, buf, NULL) == -1)
2925    return Error("Bitcode stream must be at least 16 bytes in length");
2926
2927  if (!isBitcode(buf, buf + 16))
2928    return Error("Invalid bitcode signature");
2929
2930  if (isBitcodeWrapper(buf, buf + 4)) {
2931    const unsigned char *bitcodeStart = buf;
2932    const unsigned char *bitcodeEnd = buf + 16;
2933    SkipBitcodeWrapperHeader(bitcodeStart, bitcodeEnd, false);
2934    Bytes->dropLeadingBytes(bitcodeStart - buf);
2935    Bytes->setKnownObjectSize(bitcodeEnd - bitcodeStart);
2936  }
2937  return false;
2938}
2939
2940//===----------------------------------------------------------------------===//
2941// External interface
2942//===----------------------------------------------------------------------===//
2943
2944/// getLazyBitcodeModule - lazy function-at-a-time loading from a file.
2945///
2946Module *llvm::getLazyBitcodeModule(MemoryBuffer *Buffer,
2947                                   LLVMContext& Context,
2948                                   std::string *ErrMsg) {
2949  Module *M = new Module(Buffer->getBufferIdentifier(), Context);
2950  BitcodeReader *R = new BitcodeReader(Buffer, Context);
2951  M->setMaterializer(R);
2952  if (R->ParseBitcodeInto(M)) {
2953    if (ErrMsg)
2954      *ErrMsg = R->getErrorString();
2955
2956    delete M;  // Also deletes R.
2957    return 0;
2958  }
2959  // Have the BitcodeReader dtor delete 'Buffer'.
2960  R->setBufferOwned(true);
2961
2962  R->materializeForwardReferencedFunctions();
2963
2964  return M;
2965}
2966
2967
2968Module *llvm::getStreamedBitcodeModule(const std::string &name,
2969                                       DataStreamer *streamer,
2970                                       LLVMContext &Context,
2971                                       std::string *ErrMsg) {
2972  Module *M = new Module(name, Context);
2973  BitcodeReader *R = new BitcodeReader(streamer, Context);
2974  M->setMaterializer(R);
2975  if (R->ParseBitcodeInto(M)) {
2976    if (ErrMsg)
2977      *ErrMsg = R->getErrorString();
2978    delete M;  // Also deletes R.
2979    return 0;
2980  }
2981  R->setBufferOwned(false); // no buffer to delete
2982  return M;
2983}
2984
2985/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
2986/// If an error occurs, return null and fill in *ErrMsg if non-null.
2987Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, LLVMContext& Context,
2988                               std::string *ErrMsg){
2989  Module *M = getLazyBitcodeModule(Buffer, Context, ErrMsg);
2990  if (!M) return 0;
2991
2992  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
2993  // there was an error.
2994  static_cast<BitcodeReader*>(M->getMaterializer())->setBufferOwned(false);
2995
2996  // Read in the entire module, and destroy the BitcodeReader.
2997  if (M->MaterializeAllPermanently(ErrMsg)) {
2998    delete M;
2999    return 0;
3000  }
3001
3002  // TODO: Restore the use-lists to the in-memory state when the bitcode was
3003  // written.  We must defer until the Module has been fully materialized.
3004
3005  return M;
3006}
3007
3008std::string llvm::getBitcodeTargetTriple(MemoryBuffer *Buffer,
3009                                         LLVMContext& Context,
3010                                         std::string *ErrMsg) {
3011  BitcodeReader *R = new BitcodeReader(Buffer, Context);
3012  // Don't let the BitcodeReader dtor delete 'Buffer'.
3013  R->setBufferOwned(false);
3014
3015  std::string Triple("");
3016  if (R->ParseTriple(Triple))
3017    if (ErrMsg)
3018      *ErrMsg = R->getErrorString();
3019
3020  delete R;
3021  return Triple;
3022}
3023