BitcodeReader.cpp revision 63246aa04f23767875bfe6f533285915a766b82d 
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#include "llvm/Bitcode/ReaderWriter.h"
11#include "BitcodeReader.h"
12#include "llvm/ADT/SmallString.h"
13#include "llvm/ADT/SmallVector.h"
14#include "llvm/AutoUpgrade.h"
15#include "llvm/IR/Constants.h"
16#include "llvm/IR/DerivedTypes.h"
17#include "llvm/IR/InlineAsm.h"
18#include "llvm/IR/IntrinsicInst.h"
19#include "llvm/IR/Module.h"
20#include "llvm/IR/OperandTraits.h"
21#include "llvm/IR/Operator.h"
22#include "llvm/Support/DataStream.h"
23#include "llvm/Support/MathExtras.h"
24#include "llvm/Support/MemoryBuffer.h"
25using namespace llvm;
26
27enum {
28  SWITCH_INST_MAGIC = 0x4B5 // May 2012 => 1205 => Hex
29};
30
31void BitcodeReader::materializeForwardReferencedFunctions() {
32  while (!BlockAddrFwdRefs.empty()) {
33    Function *F = BlockAddrFwdRefs.begin()->first;
34    F->Materialize();
35  }
36}
37
38void BitcodeReader::FreeState() {
39  if (BufferOwned)
40    delete Buffer;
41  Buffer = 0;
42  std::vector<Type*>().swap(TypeList);
43  ValueList.clear();
44  MDValueList.clear();
45
46  std::vector<AttributeSet>().swap(MAttributes);
47  std::vector<BasicBlock*>().swap(FunctionBBs);
48  std::vector<Function*>().swap(FunctionsWithBodies);
49  DeferredFunctionInfo.clear();
50  MDKindMap.clear();
51
52  assert(BlockAddrFwdRefs.empty() && "Unresolved blockaddress fwd references");
53}
54
55//===----------------------------------------------------------------------===//
56//  Helper functions to implement forward reference resolution, etc.
57//===----------------------------------------------------------------------===//
58
59/// ConvertToString - Convert a string from a record into an std::string, return
60/// true on failure.
61template<typename StrTy>
62static bool ConvertToString(ArrayRef<uint64_t> Record, unsigned Idx,
63                            StrTy &Result) {
64  if (Idx > Record.size())
65    return true;
66
67  for (unsigned i = Idx, e = Record.size(); i != e; ++i)
68    Result += (char)Record[i];
69  return false;
70}
71
72static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
73  switch (Val) {
74  default: // Map unknown/new linkages to external
75  case 0:  return GlobalValue::ExternalLinkage;
76  case 1:  return GlobalValue::WeakAnyLinkage;
77  case 2:  return GlobalValue::AppendingLinkage;
78  case 3:  return GlobalValue::InternalLinkage;
79  case 4:  return GlobalValue::LinkOnceAnyLinkage;
80  case 5:  return GlobalValue::DLLImportLinkage;
81  case 6:  return GlobalValue::DLLExportLinkage;
82  case 7:  return GlobalValue::ExternalWeakLinkage;
83  case 8:  return GlobalValue::CommonLinkage;
84  case 9:  return GlobalValue::PrivateLinkage;
85  case 10: return GlobalValue::WeakODRLinkage;
86  case 11: return GlobalValue::LinkOnceODRLinkage;
87  case 12: return GlobalValue::AvailableExternallyLinkage;
88  case 13: return GlobalValue::LinkerPrivateLinkage;
89  case 14: return GlobalValue::LinkerPrivateWeakLinkage;
90  case 15: return GlobalValue::LinkOnceODRAutoHideLinkage;
91  }
92}
93
94static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
95  switch (Val) {
96  default: // Map unknown visibilities to default.
97  case 0: return GlobalValue::DefaultVisibility;
98  case 1: return GlobalValue::HiddenVisibility;
99  case 2: return GlobalValue::ProtectedVisibility;
100  }
101}
102
103static GlobalVariable::ThreadLocalMode GetDecodedThreadLocalMode(unsigned Val) {
104  switch (Val) {
105    case 0: return GlobalVariable::NotThreadLocal;
106    default: // Map unknown non-zero value to general dynamic.
107    case 1: return GlobalVariable::GeneralDynamicTLSModel;
108    case 2: return GlobalVariable::LocalDynamicTLSModel;
109    case 3: return GlobalVariable::InitialExecTLSModel;
110    case 4: return GlobalVariable::LocalExecTLSModel;
111  }
112}
113
114static int GetDecodedCastOpcode(unsigned Val) {
115  switch (Val) {
116  default: return -1;
117  case bitc::CAST_TRUNC   : return Instruction::Trunc;
118  case bitc::CAST_ZEXT    : return Instruction::ZExt;
119  case bitc::CAST_SEXT    : return Instruction::SExt;
120  case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
121  case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
122  case bitc::CAST_UITOFP  : return Instruction::UIToFP;
123  case bitc::CAST_SITOFP  : return Instruction::SIToFP;
124  case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
125  case bitc::CAST_FPEXT   : return Instruction::FPExt;
126  case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
127  case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
128  case bitc::CAST_BITCAST : return Instruction::BitCast;
129  }
130}
131static int GetDecodedBinaryOpcode(unsigned Val, Type *Ty) {
132  switch (Val) {
133  default: return -1;
134  case bitc::BINOP_ADD:
135    return Ty->isFPOrFPVectorTy() ? Instruction::FAdd : Instruction::Add;
136  case bitc::BINOP_SUB:
137    return Ty->isFPOrFPVectorTy() ? Instruction::FSub : Instruction::Sub;
138  case bitc::BINOP_MUL:
139    return Ty->isFPOrFPVectorTy() ? Instruction::FMul : Instruction::Mul;
140  case bitc::BINOP_UDIV: return Instruction::UDiv;
141  case bitc::BINOP_SDIV:
142    return Ty->isFPOrFPVectorTy() ? Instruction::FDiv : Instruction::SDiv;
143  case bitc::BINOP_UREM: return Instruction::URem;
144  case bitc::BINOP_SREM:
145    return Ty->isFPOrFPVectorTy() ? Instruction::FRem : Instruction::SRem;
146  case bitc::BINOP_SHL:  return Instruction::Shl;
147  case bitc::BINOP_LSHR: return Instruction::LShr;
148  case bitc::BINOP_ASHR: return Instruction::AShr;
149  case bitc::BINOP_AND:  return Instruction::And;
150  case bitc::BINOP_OR:   return Instruction::Or;
151  case bitc::BINOP_XOR:  return Instruction::Xor;
152  }
153}
154
155static AtomicRMWInst::BinOp GetDecodedRMWOperation(unsigned Val) {
156  switch (Val) {
157  default: return AtomicRMWInst::BAD_BINOP;
158  case bitc::RMW_XCHG: return AtomicRMWInst::Xchg;
159  case bitc::RMW_ADD: return AtomicRMWInst::Add;
160  case bitc::RMW_SUB: return AtomicRMWInst::Sub;
161  case bitc::RMW_AND: return AtomicRMWInst::And;
162  case bitc::RMW_NAND: return AtomicRMWInst::Nand;
163  case bitc::RMW_OR: return AtomicRMWInst::Or;
164  case bitc::RMW_XOR: return AtomicRMWInst::Xor;
165  case bitc::RMW_MAX: return AtomicRMWInst::Max;
166  case bitc::RMW_MIN: return AtomicRMWInst::Min;
167  case bitc::RMW_UMAX: return AtomicRMWInst::UMax;
168  case bitc::RMW_UMIN: return AtomicRMWInst::UMin;
169  }
170}
171
172static AtomicOrdering GetDecodedOrdering(unsigned Val) {
173  switch (Val) {
174  case bitc::ORDERING_NOTATOMIC: return NotAtomic;
175  case bitc::ORDERING_UNORDERED: return Unordered;
176  case bitc::ORDERING_MONOTONIC: return Monotonic;
177  case bitc::ORDERING_ACQUIRE: return Acquire;
178  case bitc::ORDERING_RELEASE: return Release;
179  case bitc::ORDERING_ACQREL: return AcquireRelease;
180  default: // Map unknown orderings to sequentially-consistent.
181  case bitc::ORDERING_SEQCST: return SequentiallyConsistent;
182  }
183}
184
185static SynchronizationScope GetDecodedSynchScope(unsigned Val) {
186  switch (Val) {
187  case bitc::SYNCHSCOPE_SINGLETHREAD: return SingleThread;
188  default: // Map unknown scopes to cross-thread.
189  case bitc::SYNCHSCOPE_CROSSTHREAD: return CrossThread;
190  }
191}
192
193namespace llvm {
194namespace {
195  /// @brief A class for maintaining the slot number definition
196  /// as a placeholder for the actual definition for forward constants defs.
197  class ConstantPlaceHolder : public ConstantExpr {
198    void operator=(const ConstantPlaceHolder &) LLVM_DELETED_FUNCTION;
199  public:
200    // allocate space for exactly one operand
201    void *operator new(size_t s) {
202      return User::operator new(s, 1);
203    }
204    explicit ConstantPlaceHolder(Type *Ty, LLVMContext& Context)
205      : ConstantExpr(Ty, Instruction::UserOp1, &Op<0>(), 1) {
206      Op<0>() = UndefValue::get(Type::getInt32Ty(Context));
207    }
208
209    /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
210    static bool classof(const Value *V) {
211      return isa<ConstantExpr>(V) &&
212             cast<ConstantExpr>(V)->getOpcode() == Instruction::UserOp1;
213    }
214
215
216    /// Provide fast operand accessors
217    //DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
218  };
219}
220
221// FIXME: can we inherit this from ConstantExpr?
222template <>
223struct OperandTraits<ConstantPlaceHolder> :
224  public FixedNumOperandTraits<ConstantPlaceHolder, 1> {
225};
226}
227
228
229void BitcodeReaderValueList::AssignValue(Value *V, unsigned Idx) {
230  if (Idx == size()) {
231    push_back(V);
232    return;
233  }
234
235  if (Idx >= size())
236    resize(Idx+1);
237
238  WeakVH &OldV = ValuePtrs[Idx];
239  if (OldV == 0) {
240    OldV = V;
241    return;
242  }
243
244  // Handle constants and non-constants (e.g. instrs) differently for
245  // efficiency.
246  if (Constant *PHC = dyn_cast<Constant>(&*OldV)) {
247    ResolveConstants.push_back(std::make_pair(PHC, Idx));
248    OldV = V;
249  } else {
250    // If there was a forward reference to this value, replace it.
251    Value *PrevVal = OldV;
252    OldV->replaceAllUsesWith(V);
253    delete PrevVal;
254  }
255}
256
257
258Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
259                                                    Type *Ty) {
260  if (Idx >= size())
261    resize(Idx + 1);
262
263  if (Value *V = ValuePtrs[Idx]) {
264    assert(Ty == V->getType() && "Type mismatch in constant table!");
265    return cast<Constant>(V);
266  }
267
268  // Create and return a placeholder, which will later be RAUW'd.
269  Constant *C = new ConstantPlaceHolder(Ty, Context);
270  ValuePtrs[Idx] = C;
271  return C;
272}
273
274Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, Type *Ty) {
275  if (Idx >= size())
276    resize(Idx + 1);
277
278  if (Value *V = ValuePtrs[Idx]) {
279    assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
280    return V;
281  }
282
283  // No type specified, must be invalid reference.
284  if (Ty == 0) return 0;
285
286  // Create and return a placeholder, which will later be RAUW'd.
287  Value *V = new Argument(Ty);
288  ValuePtrs[Idx] = V;
289  return V;
290}
291
292/// ResolveConstantForwardRefs - Once all constants are read, this method bulk
293/// resolves any forward references.  The idea behind this is that we sometimes
294/// get constants (such as large arrays) which reference *many* forward ref
295/// constants.  Replacing each of these causes a lot of thrashing when
296/// building/reuniquing the constant.  Instead of doing this, we look at all the
297/// uses and rewrite all the place holders at once for any constant that uses
298/// a placeholder.
299void BitcodeReaderValueList::ResolveConstantForwardRefs() {
300  // Sort the values by-pointer so that they are efficient to look up with a
301  // binary search.
302  std::sort(ResolveConstants.begin(), ResolveConstants.end());
303
304  SmallVector<Constant*, 64> NewOps;
305
306  while (!ResolveConstants.empty()) {
307    Value *RealVal = operator[](ResolveConstants.back().second);
308    Constant *Placeholder = ResolveConstants.back().first;
309    ResolveConstants.pop_back();
310
311    // Loop over all users of the placeholder, updating them to reference the
312    // new value.  If they reference more than one placeholder, update them all
313    // at once.
314    while (!Placeholder->use_empty()) {
315      Value::use_iterator UI = Placeholder->use_begin();
316      User *U = *UI;
317
318      // If the using object isn't uniqued, just update the operands.  This
319      // handles instructions and initializers for global variables.
320      if (!isa<Constant>(U) || isa<GlobalValue>(U)) {
321        UI.getUse().set(RealVal);
322        continue;
323      }
324
325      // Otherwise, we have a constant that uses the placeholder.  Replace that
326      // constant with a new constant that has *all* placeholder uses updated.
327      Constant *UserC = cast<Constant>(U);
328      for (User::op_iterator I = UserC->op_begin(), E = UserC->op_end();
329           I != E; ++I) {
330        Value *NewOp;
331        if (!isa<ConstantPlaceHolder>(*I)) {
332          // Not a placeholder reference.
333          NewOp = *I;
334        } else if (*I == Placeholder) {
335          // Common case is that it just references this one placeholder.
336          NewOp = RealVal;
337        } else {
338          // Otherwise, look up the placeholder in ResolveConstants.
339          ResolveConstantsTy::iterator It =
340            std::lower_bound(ResolveConstants.begin(), ResolveConstants.end(),
341                             std::pair<Constant*, unsigned>(cast<Constant>(*I),
342                                                            0));
343          assert(It != ResolveConstants.end() && It->first == *I);
344          NewOp = operator[](It->second);
345        }
346
347        NewOps.push_back(cast<Constant>(NewOp));
348      }
349
350      // Make the new constant.
351      Constant *NewC;
352      if (ConstantArray *UserCA = dyn_cast<ConstantArray>(UserC)) {
353        NewC = ConstantArray::get(UserCA->getType(), NewOps);
354      } else if (ConstantStruct *UserCS = dyn_cast<ConstantStruct>(UserC)) {
355        NewC = ConstantStruct::get(UserCS->getType(), NewOps);
356      } else if (isa<ConstantVector>(UserC)) {
357        NewC = ConstantVector::get(NewOps);
358      } else {
359        assert(isa<ConstantExpr>(UserC) && "Must be a ConstantExpr.");
360        NewC = cast<ConstantExpr>(UserC)->getWithOperands(NewOps);
361      }
362
363      UserC->replaceAllUsesWith(NewC);
364      UserC->destroyConstant();
365      NewOps.clear();
366    }
367
368    // Update all ValueHandles, they should be the only users at this point.
369    Placeholder->replaceAllUsesWith(RealVal);
370    delete Placeholder;
371  }
372}
373
374void BitcodeReaderMDValueList::AssignValue(Value *V, unsigned Idx) {
375  if (Idx == size()) {
376    push_back(V);
377    return;
378  }
379
380  if (Idx >= size())
381    resize(Idx+1);
382
383  WeakVH &OldV = MDValuePtrs[Idx];
384  if (OldV == 0) {
385    OldV = V;
386    return;
387  }
388
389  // If there was a forward reference to this value, replace it.
390  MDNode *PrevVal = cast<MDNode>(OldV);
391  OldV->replaceAllUsesWith(V);
392  MDNode::deleteTemporary(PrevVal);
393  // Deleting PrevVal sets Idx value in MDValuePtrs to null. Set new
394  // value for Idx.
395  MDValuePtrs[Idx] = V;
396}
397
398Value *BitcodeReaderMDValueList::getValueFwdRef(unsigned Idx) {
399  if (Idx >= size())
400    resize(Idx + 1);
401
402  if (Value *V = MDValuePtrs[Idx]) {
403    assert(V->getType()->isMetadataTy() && "Type mismatch in value table!");
404    return V;
405  }
406
407  // Create and return a placeholder, which will later be RAUW'd.
408  Value *V = MDNode::getTemporary(Context, ArrayRef<Value*>());
409  MDValuePtrs[Idx] = V;
410  return V;
411}
412
413Type *BitcodeReader::getTypeByID(unsigned ID) {
414  // The type table size is always specified correctly.
415  if (ID >= TypeList.size())
416    return 0;
417
418  if (Type *Ty = TypeList[ID])
419    return Ty;
420
421  // If we have a forward reference, the only possible case is when it is to a
422  // named struct.  Just create a placeholder for now.
423  return TypeList[ID] = StructType::create(Context);
424}
425
426
427//===----------------------------------------------------------------------===//
428//  Functions for parsing blocks from the bitcode file
429//===----------------------------------------------------------------------===//
430
431bool BitcodeReader::ParseAttributeBlock() {
432  if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
433    return Error("Malformed block record");
434
435  if (!MAttributes.empty())
436    return Error("Multiple PARAMATTR blocks found!");
437
438  SmallVector<uint64_t, 64> Record;
439
440  SmallVector<AttributeWithIndex, 8> Attrs;
441
442  // Read all the records.
443  while (1) {
444    unsigned Code = Stream.ReadCode();
445    if (Code == bitc::END_BLOCK) {
446      if (Stream.ReadBlockEnd())
447        return Error("Error at end of PARAMATTR block");
448      return false;
449    }
450
451    if (Code == bitc::ENTER_SUBBLOCK) {
452      // No known subblocks, always skip them.
453      Stream.ReadSubBlockID();
454      if (Stream.SkipBlock())
455        return Error("Malformed block record");
456      continue;
457    }
458
459    if (Code == bitc::DEFINE_ABBREV) {
460      Stream.ReadAbbrevRecord();
461      continue;
462    }
463
464    // Read a record.
465    Record.clear();
466    switch (Stream.ReadRecord(Code, Record)) {
467    default:  // Default behavior: ignore.
468      break;
469    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
470      if (Record.size() & 1)
471        return Error("Invalid ENTRY record");
472
473      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
474        Attribute ReconstitutedAttr =
475          Attribute::decodeLLVMAttributesForBitcode(Context, Record[i+1]);
476        Record[i+1] = ReconstitutedAttr.Raw();
477      }
478
479      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
480        AttrBuilder B(Record[i+1]);
481        if (B.hasAttributes())
482          Attrs.push_back(AttributeWithIndex::get(Record[i],
483                                                  Attribute::get(Context, B)));
484      }
485
486      MAttributes.push_back(AttributeSet::get(Context, Attrs));
487      Attrs.clear();
488      break;
489    }
490    }
491  }
492}
493
494bool BitcodeReader::ParseTypeTable() {
495  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID_NEW))
496    return Error("Malformed block record");
497
498  return ParseTypeTableBody();
499}
500
501bool BitcodeReader::ParseTypeTableBody() {
502  if (!TypeList.empty())
503    return Error("Multiple TYPE_BLOCKs found!");
504
505  SmallVector<uint64_t, 64> Record;
506  unsigned NumRecords = 0;
507
508  SmallString<64> TypeName;
509
510  // Read all the records for this type table.
511  while (1) {
512    unsigned Code = Stream.ReadCode();
513    if (Code == bitc::END_BLOCK) {
514      if (NumRecords != TypeList.size())
515        return Error("Invalid type forward reference in TYPE_BLOCK");
516      if (Stream.ReadBlockEnd())
517        return Error("Error at end of type table block");
518      return false;
519    }
520
521    if (Code == bitc::ENTER_SUBBLOCK) {
522      // No known subblocks, always skip them.
523      Stream.ReadSubBlockID();
524      if (Stream.SkipBlock())
525        return Error("Malformed block record");
526      continue;
527    }
528
529    if (Code == bitc::DEFINE_ABBREV) {
530      Stream.ReadAbbrevRecord();
531      continue;
532    }
533
534    // Read a record.
535    Record.clear();
536    Type *ResultTy = 0;
537    switch (Stream.ReadRecord(Code, Record)) {
538    default: return Error("unknown type in type table");
539    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
540      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
541      // type list.  This allows us to reserve space.
542      if (Record.size() < 1)
543        return Error("Invalid TYPE_CODE_NUMENTRY record");
544      TypeList.resize(Record[0]);
545      continue;
546    case bitc::TYPE_CODE_VOID:      // VOID
547      ResultTy = Type::getVoidTy(Context);
548      break;
549    case bitc::TYPE_CODE_HALF:     // HALF
550      ResultTy = Type::getHalfTy(Context);
551      break;
552    case bitc::TYPE_CODE_FLOAT:     // FLOAT
553      ResultTy = Type::getFloatTy(Context);
554      break;
555    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
556      ResultTy = Type::getDoubleTy(Context);
557      break;
558    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
559      ResultTy = Type::getX86_FP80Ty(Context);
560      break;
561    case bitc::TYPE_CODE_FP128:     // FP128
562      ResultTy = Type::getFP128Ty(Context);
563      break;
564    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
565      ResultTy = Type::getPPC_FP128Ty(Context);
566      break;
567    case bitc::TYPE_CODE_LABEL:     // LABEL
568      ResultTy = Type::getLabelTy(Context);
569      break;
570    case bitc::TYPE_CODE_METADATA:  // METADATA
571      ResultTy = Type::getMetadataTy(Context);
572      break;
573    case bitc::TYPE_CODE_X86_MMX:   // X86_MMX
574      ResultTy = Type::getX86_MMXTy(Context);
575      break;
576    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
577      if (Record.size() < 1)
578        return Error("Invalid Integer type record");
579
580      ResultTy = IntegerType::get(Context, Record[0]);
581      break;
582    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
583                                    //          [pointee type, address space]
584      if (Record.size() < 1)
585        return Error("Invalid POINTER type record");
586      unsigned AddressSpace = 0;
587      if (Record.size() == 2)
588        AddressSpace = Record[1];
589      ResultTy = getTypeByID(Record[0]);
590      if (ResultTy == 0) return Error("invalid element type in pointer type");
591      ResultTy = PointerType::get(ResultTy, AddressSpace);
592      break;
593    }
594    case bitc::TYPE_CODE_FUNCTION_OLD: {
595      // FIXME: attrid is dead, remove it in LLVM 4.0
596      // FUNCTION: [vararg, attrid, retty, paramty x N]
597      if (Record.size() < 3)
598        return Error("Invalid FUNCTION type record");
599      SmallVector<Type*, 8> ArgTys;
600      for (unsigned i = 3, e = Record.size(); i != e; ++i) {
601        if (Type *T = getTypeByID(Record[i]))
602          ArgTys.push_back(T);
603        else
604          break;
605      }
606
607      ResultTy = getTypeByID(Record[2]);
608      if (ResultTy == 0 || ArgTys.size() < Record.size()-3)
609        return Error("invalid type in function type");
610
611      ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
612      break;
613    }
614    case bitc::TYPE_CODE_FUNCTION: {
615      // FUNCTION: [vararg, retty, paramty x N]
616      if (Record.size() < 2)
617        return Error("Invalid FUNCTION type record");
618      SmallVector<Type*, 8> ArgTys;
619      for (unsigned i = 2, e = Record.size(); i != e; ++i) {
620        if (Type *T = getTypeByID(Record[i]))
621          ArgTys.push_back(T);
622        else
623          break;
624      }
625
626      ResultTy = getTypeByID(Record[1]);
627      if (ResultTy == 0 || ArgTys.size() < Record.size()-2)
628        return Error("invalid type in function type");
629
630      ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
631      break;
632    }
633    case bitc::TYPE_CODE_STRUCT_ANON: {  // STRUCT: [ispacked, eltty x N]
634      if (Record.size() < 1)
635        return Error("Invalid STRUCT type record");
636      SmallVector<Type*, 8> EltTys;
637      for (unsigned i = 1, e = Record.size(); i != e; ++i) {
638        if (Type *T = getTypeByID(Record[i]))
639          EltTys.push_back(T);
640        else
641          break;
642      }
643      if (EltTys.size() != Record.size()-1)
644        return Error("invalid type in struct type");
645      ResultTy = StructType::get(Context, EltTys, Record[0]);
646      break;
647    }
648    case bitc::TYPE_CODE_STRUCT_NAME:   // STRUCT_NAME: [strchr x N]
649      if (ConvertToString(Record, 0, TypeName))
650        return Error("Invalid STRUCT_NAME record");
651      continue;
652
653    case bitc::TYPE_CODE_STRUCT_NAMED: { // STRUCT: [ispacked, eltty x N]
654      if (Record.size() < 1)
655        return Error("Invalid STRUCT type record");
656
657      if (NumRecords >= TypeList.size())
658        return Error("invalid TYPE table");
659
660      // Check to see if this was forward referenced, if so fill in the temp.
661      StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
662      if (Res) {
663        Res->setName(TypeName);
664        TypeList[NumRecords] = 0;
665      } else  // Otherwise, create a new struct.
666        Res = StructType::create(Context, TypeName);
667      TypeName.clear();
668
669      SmallVector<Type*, 8> EltTys;
670      for (unsigned i = 1, e = Record.size(); i != e; ++i) {
671        if (Type *T = getTypeByID(Record[i]))
672          EltTys.push_back(T);
673        else
674          break;
675      }
676      if (EltTys.size() != Record.size()-1)
677        return Error("invalid STRUCT type record");
678      Res->setBody(EltTys, Record[0]);
679      ResultTy = Res;
680      break;
681    }
682    case bitc::TYPE_CODE_OPAQUE: {       // OPAQUE: []
683      if (Record.size() != 1)
684        return Error("Invalid OPAQUE type record");
685
686      if (NumRecords >= TypeList.size())
687        return Error("invalid TYPE table");
688
689      // Check to see if this was forward referenced, if so fill in the temp.
690      StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
691      if (Res) {
692        Res->setName(TypeName);
693        TypeList[NumRecords] = 0;
694      } else  // Otherwise, create a new struct with no body.
695        Res = StructType::create(Context, TypeName);
696      TypeName.clear();
697      ResultTy = Res;
698      break;
699    }
700    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
701      if (Record.size() < 2)
702        return Error("Invalid ARRAY type record");
703      if ((ResultTy = getTypeByID(Record[1])))
704        ResultTy = ArrayType::get(ResultTy, Record[0]);
705      else
706        return Error("Invalid ARRAY type element");
707      break;
708    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
709      if (Record.size() < 2)
710        return Error("Invalid VECTOR type record");
711      if ((ResultTy = getTypeByID(Record[1])))
712        ResultTy = VectorType::get(ResultTy, Record[0]);
713      else
714        return Error("Invalid ARRAY type element");
715      break;
716    }
717
718    if (NumRecords >= TypeList.size())
719      return Error("invalid TYPE table");
720    assert(ResultTy && "Didn't read a type?");
721    assert(TypeList[NumRecords] == 0 && "Already read type?");
722    TypeList[NumRecords++] = ResultTy;
723  }
724}
725
726bool BitcodeReader::ParseValueSymbolTable() {
727  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
728    return Error("Malformed block record");
729
730  SmallVector<uint64_t, 64> Record;
731
732  // Read all the records for this value table.
733  SmallString<128> ValueName;
734  while (1) {
735    unsigned Code = Stream.ReadCode();
736    if (Code == bitc::END_BLOCK) {
737      if (Stream.ReadBlockEnd())
738        return Error("Error at end of value symbol table block");
739      return false;
740    }
741    if (Code == bitc::ENTER_SUBBLOCK) {
742      // No known subblocks, always skip them.
743      Stream.ReadSubBlockID();
744      if (Stream.SkipBlock())
745        return Error("Malformed block record");
746      continue;
747    }
748
749    if (Code == bitc::DEFINE_ABBREV) {
750      Stream.ReadAbbrevRecord();
751      continue;
752    }
753
754    // Read a record.
755    Record.clear();
756    switch (Stream.ReadRecord(Code, Record)) {
757    default:  // Default behavior: unknown type.
758      break;
759    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
760      if (ConvertToString(Record, 1, ValueName))
761        return Error("Invalid VST_ENTRY record");
762      unsigned ValueID = Record[0];
763      if (ValueID >= ValueList.size())
764        return Error("Invalid Value ID in VST_ENTRY record");
765      Value *V = ValueList[ValueID];
766
767      V->setName(StringRef(ValueName.data(), ValueName.size()));
768      ValueName.clear();
769      break;
770    }
771    case bitc::VST_CODE_BBENTRY: {
772      if (ConvertToString(Record, 1, ValueName))
773        return Error("Invalid VST_BBENTRY record");
774      BasicBlock *BB = getBasicBlock(Record[0]);
775      if (BB == 0)
776        return Error("Invalid BB ID in VST_BBENTRY record");
777
778      BB->setName(StringRef(ValueName.data(), ValueName.size()));
779      ValueName.clear();
780      break;
781    }
782    }
783  }
784}
785
786bool BitcodeReader::ParseMetadata() {
787  unsigned NextMDValueNo = MDValueList.size();
788
789  if (Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
790    return Error("Malformed block record");
791
792  SmallVector<uint64_t, 64> Record;
793
794  // Read all the records.
795  while (1) {
796    unsigned Code = Stream.ReadCode();
797    if (Code == bitc::END_BLOCK) {
798      if (Stream.ReadBlockEnd())
799        return Error("Error at end of PARAMATTR block");
800      return false;
801    }
802
803    if (Code == bitc::ENTER_SUBBLOCK) {
804      // No known subblocks, always skip them.
805      Stream.ReadSubBlockID();
806      if (Stream.SkipBlock())
807        return Error("Malformed block record");
808      continue;
809    }
810
811    if (Code == bitc::DEFINE_ABBREV) {
812      Stream.ReadAbbrevRecord();
813      continue;
814    }
815
816    bool IsFunctionLocal = false;
817    // Read a record.
818    Record.clear();
819    Code = Stream.ReadRecord(Code, Record);
820    switch (Code) {
821    default:  // Default behavior: ignore.
822      break;
823    case bitc::METADATA_NAME: {
824      // Read named of the named metadata.
825      SmallString<8> Name(Record.begin(), Record.end());
826      Record.clear();
827      Code = Stream.ReadCode();
828
829      // METADATA_NAME is always followed by METADATA_NAMED_NODE.
830      unsigned NextBitCode = Stream.ReadRecord(Code, Record);
831      assert(NextBitCode == bitc::METADATA_NAMED_NODE); (void)NextBitCode;
832
833      // Read named metadata elements.
834      unsigned Size = Record.size();
835      NamedMDNode *NMD = TheModule->getOrInsertNamedMetadata(Name);
836      for (unsigned i = 0; i != Size; ++i) {
837        MDNode *MD = dyn_cast<MDNode>(MDValueList.getValueFwdRef(Record[i]));
838        if (MD == 0)
839          return Error("Malformed metadata record");
840        NMD->addOperand(MD);
841      }
842      break;
843    }
844    case bitc::METADATA_FN_NODE:
845      IsFunctionLocal = true;
846      // fall-through
847    case bitc::METADATA_NODE: {
848      if (Record.size() % 2 == 1)
849        return Error("Invalid METADATA_NODE record");
850
851      unsigned Size = Record.size();
852      SmallVector<Value*, 8> Elts;
853      for (unsigned i = 0; i != Size; i += 2) {
854        Type *Ty = getTypeByID(Record[i]);
855        if (!Ty) return Error("Invalid METADATA_NODE record");
856        if (Ty->isMetadataTy())
857          Elts.push_back(MDValueList.getValueFwdRef(Record[i+1]));
858        else if (!Ty->isVoidTy())
859          Elts.push_back(ValueList.getValueFwdRef(Record[i+1], Ty));
860        else
861          Elts.push_back(NULL);
862      }
863      Value *V = MDNode::getWhenValsUnresolved(Context, Elts, IsFunctionLocal);
864      IsFunctionLocal = false;
865      MDValueList.AssignValue(V, NextMDValueNo++);
866      break;
867    }
868    case bitc::METADATA_STRING: {
869      SmallString<8> String(Record.begin(), Record.end());
870      Value *V = MDString::get(Context, String);
871      MDValueList.AssignValue(V, NextMDValueNo++);
872      break;
873    }
874    case bitc::METADATA_KIND: {
875      if (Record.size() < 2)
876        return Error("Invalid METADATA_KIND record");
877
878      unsigned Kind = Record[0];
879      SmallString<8> Name(Record.begin()+1, Record.end());
880
881      unsigned NewKind = TheModule->getMDKindID(Name.str());
882      if (!MDKindMap.insert(std::make_pair(Kind, NewKind)).second)
883        return Error("Conflicting METADATA_KIND records");
884      break;
885    }
886    }
887  }
888}
889
890/// decodeSignRotatedValue - Decode a signed value stored with the sign bit in
891/// the LSB for dense VBR encoding.
892uint64_t BitcodeReader::decodeSignRotatedValue(uint64_t V) {
893  if ((V & 1) == 0)
894    return V >> 1;
895  if (V != 1)
896    return -(V >> 1);
897  // There is no such thing as -0 with integers.  "-0" really means MININT.
898  return 1ULL << 63;
899}
900
901/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
902/// values and aliases that we can.
903bool BitcodeReader::ResolveGlobalAndAliasInits() {
904  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
905  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
906
907  GlobalInitWorklist.swap(GlobalInits);
908  AliasInitWorklist.swap(AliasInits);
909
910  while (!GlobalInitWorklist.empty()) {
911    unsigned ValID = GlobalInitWorklist.back().second;
912    if (ValID >= ValueList.size()) {
913      // Not ready to resolve this yet, it requires something later in the file.
914      GlobalInits.push_back(GlobalInitWorklist.back());
915    } else {
916      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
917        GlobalInitWorklist.back().first->setInitializer(C);
918      else
919        return Error("Global variable initializer is not a constant!");
920    }
921    GlobalInitWorklist.pop_back();
922  }
923
924  while (!AliasInitWorklist.empty()) {
925    unsigned ValID = AliasInitWorklist.back().second;
926    if (ValID >= ValueList.size()) {
927      AliasInits.push_back(AliasInitWorklist.back());
928    } else {
929      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
930        AliasInitWorklist.back().first->setAliasee(C);
931      else
932        return Error("Alias initializer is not a constant!");
933    }
934    AliasInitWorklist.pop_back();
935  }
936  return false;
937}
938
939static APInt ReadWideAPInt(ArrayRef<uint64_t> Vals, unsigned TypeBits) {
940  SmallVector<uint64_t, 8> Words(Vals.size());
941  std::transform(Vals.begin(), Vals.end(), Words.begin(),
942                 BitcodeReader::decodeSignRotatedValue);
943
944  return APInt(TypeBits, Words);
945}
946
947bool BitcodeReader::ParseConstants() {
948  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
949    return Error("Malformed block record");
950
951  SmallVector<uint64_t, 64> Record;
952
953  // Read all the records for this value table.
954  Type *CurTy = Type::getInt32Ty(Context);
955  unsigned NextCstNo = ValueList.size();
956  while (1) {
957    unsigned Code = Stream.ReadCode();
958    if (Code == bitc::END_BLOCK)
959      break;
960
961    if (Code == bitc::ENTER_SUBBLOCK) {
962      // No known subblocks, always skip them.
963      Stream.ReadSubBlockID();
964      if (Stream.SkipBlock())
965        return Error("Malformed block record");
966      continue;
967    }
968
969    if (Code == bitc::DEFINE_ABBREV) {
970      Stream.ReadAbbrevRecord();
971      continue;
972    }
973
974    // Read a record.
975    Record.clear();
976    Value *V = 0;
977    unsigned BitCode = Stream.ReadRecord(Code, Record);
978    switch (BitCode) {
979    default:  // Default behavior: unknown constant
980    case bitc::CST_CODE_UNDEF:     // UNDEF
981      V = UndefValue::get(CurTy);
982      break;
983    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
984      if (Record.empty())
985        return Error("Malformed CST_SETTYPE record");
986      if (Record[0] >= TypeList.size())
987        return Error("Invalid Type ID in CST_SETTYPE record");
988      CurTy = TypeList[Record[0]];
989      continue;  // Skip the ValueList manipulation.
990    case bitc::CST_CODE_NULL:      // NULL
991      V = Constant::getNullValue(CurTy);
992      break;
993    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
994      if (!CurTy->isIntegerTy() || Record.empty())
995        return Error("Invalid CST_INTEGER record");
996      V = ConstantInt::get(CurTy, decodeSignRotatedValue(Record[0]));
997      break;
998    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
999      if (!CurTy->isIntegerTy() || Record.empty())
1000        return Error("Invalid WIDE_INTEGER record");
1001
1002      APInt VInt = ReadWideAPInt(Record,
1003                                 cast<IntegerType>(CurTy)->getBitWidth());
1004      V = ConstantInt::get(Context, VInt);
1005
1006      break;
1007    }
1008    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
1009      if (Record.empty())
1010        return Error("Invalid FLOAT record");
1011      if (CurTy->isHalfTy())
1012        V = ConstantFP::get(Context, APFloat(APInt(16, (uint16_t)Record[0])));
1013      else if (CurTy->isFloatTy())
1014        V = ConstantFP::get(Context, APFloat(APInt(32, (uint32_t)Record[0])));
1015      else if (CurTy->isDoubleTy())
1016        V = ConstantFP::get(Context, APFloat(APInt(64, Record[0])));
1017      else if (CurTy->isX86_FP80Ty()) {
1018        // Bits are not stored the same way as a normal i80 APInt, compensate.
1019        uint64_t Rearrange[2];
1020        Rearrange[0] = (Record[1] & 0xffffLL) | (Record[0] << 16);
1021        Rearrange[1] = Record[0] >> 48;
1022        V = ConstantFP::get(Context, APFloat(APInt(80, Rearrange)));
1023      } else if (CurTy->isFP128Ty())
1024        V = ConstantFP::get(Context, APFloat(APInt(128, Record), true));
1025      else if (CurTy->isPPC_FP128Ty())
1026        V = ConstantFP::get(Context, APFloat(APInt(128, Record)));
1027      else
1028        V = UndefValue::get(CurTy);
1029      break;
1030    }
1031
1032    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
1033      if (Record.empty())
1034        return Error("Invalid CST_AGGREGATE record");
1035
1036      unsigned Size = Record.size();
1037      SmallVector<Constant*, 16> Elts;
1038
1039      if (StructType *STy = dyn_cast<StructType>(CurTy)) {
1040        for (unsigned i = 0; i != Size; ++i)
1041          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
1042                                                     STy->getElementType(i)));
1043        V = ConstantStruct::get(STy, Elts);
1044      } else if (ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
1045        Type *EltTy = ATy->getElementType();
1046        for (unsigned i = 0; i != Size; ++i)
1047          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1048        V = ConstantArray::get(ATy, Elts);
1049      } else if (VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
1050        Type *EltTy = VTy->getElementType();
1051        for (unsigned i = 0; i != Size; ++i)
1052          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1053        V = ConstantVector::get(Elts);
1054      } else {
1055        V = UndefValue::get(CurTy);
1056      }
1057      break;
1058    }
1059    case bitc::CST_CODE_STRING:    // STRING: [values]
1060    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
1061      if (Record.empty())
1062        return Error("Invalid CST_STRING record");
1063
1064      SmallString<16> Elts(Record.begin(), Record.end());
1065      V = ConstantDataArray::getString(Context, Elts,
1066                                       BitCode == bitc::CST_CODE_CSTRING);
1067      break;
1068    }
1069    case bitc::CST_CODE_DATA: {// DATA: [n x value]
1070      if (Record.empty())
1071        return Error("Invalid CST_DATA record");
1072
1073      Type *EltTy = cast<SequentialType>(CurTy)->getElementType();
1074      unsigned Size = Record.size();
1075
1076      if (EltTy->isIntegerTy(8)) {
1077        SmallVector<uint8_t, 16> Elts(Record.begin(), Record.end());
1078        if (isa<VectorType>(CurTy))
1079          V = ConstantDataVector::get(Context, Elts);
1080        else
1081          V = ConstantDataArray::get(Context, Elts);
1082      } else if (EltTy->isIntegerTy(16)) {
1083        SmallVector<uint16_t, 16> Elts(Record.begin(), Record.end());
1084        if (isa<VectorType>(CurTy))
1085          V = ConstantDataVector::get(Context, Elts);
1086        else
1087          V = ConstantDataArray::get(Context, Elts);
1088      } else if (EltTy->isIntegerTy(32)) {
1089        SmallVector<uint32_t, 16> Elts(Record.begin(), Record.end());
1090        if (isa<VectorType>(CurTy))
1091          V = ConstantDataVector::get(Context, Elts);
1092        else
1093          V = ConstantDataArray::get(Context, Elts);
1094      } else if (EltTy->isIntegerTy(64)) {
1095        SmallVector<uint64_t, 16> Elts(Record.begin(), Record.end());
1096        if (isa<VectorType>(CurTy))
1097          V = ConstantDataVector::get(Context, Elts);
1098        else
1099          V = ConstantDataArray::get(Context, Elts);
1100      } else if (EltTy->isFloatTy()) {
1101        SmallVector<float, 16> Elts(Size);
1102        std::transform(Record.begin(), Record.end(), Elts.begin(), BitsToFloat);
1103        if (isa<VectorType>(CurTy))
1104          V = ConstantDataVector::get(Context, Elts);
1105        else
1106          V = ConstantDataArray::get(Context, Elts);
1107      } else if (EltTy->isDoubleTy()) {
1108        SmallVector<double, 16> Elts(Size);
1109        std::transform(Record.begin(), Record.end(), Elts.begin(),
1110                       BitsToDouble);
1111        if (isa<VectorType>(CurTy))
1112          V = ConstantDataVector::get(Context, Elts);
1113        else
1114          V = ConstantDataArray::get(Context, Elts);
1115      } else {
1116        return Error("Unknown element type in CE_DATA");
1117      }
1118      break;
1119    }
1120
1121    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
1122      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
1123      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
1124      if (Opc < 0) {
1125        V = UndefValue::get(CurTy);  // Unknown binop.
1126      } else {
1127        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
1128        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
1129        unsigned Flags = 0;
1130        if (Record.size() >= 4) {
1131          if (Opc == Instruction::Add ||
1132              Opc == Instruction::Sub ||
1133              Opc == Instruction::Mul ||
1134              Opc == Instruction::Shl) {
1135            if (Record[3] & (1 << bitc::OBO_NO_SIGNED_WRAP))
1136              Flags |= OverflowingBinaryOperator::NoSignedWrap;
1137            if (Record[3] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
1138              Flags |= OverflowingBinaryOperator::NoUnsignedWrap;
1139          } else if (Opc == Instruction::SDiv ||
1140                     Opc == Instruction::UDiv ||
1141                     Opc == Instruction::LShr ||
1142                     Opc == Instruction::AShr) {
1143            if (Record[3] & (1 << bitc::PEO_EXACT))
1144              Flags |= SDivOperator::IsExact;
1145          }
1146        }
1147        V = ConstantExpr::get(Opc, LHS, RHS, Flags);
1148      }
1149      break;
1150    }
1151    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
1152      if (Record.size() < 3) return Error("Invalid CE_CAST record");
1153      int Opc = GetDecodedCastOpcode(Record[0]);
1154      if (Opc < 0) {
1155        V = UndefValue::get(CurTy);  // Unknown cast.
1156      } else {
1157        Type *OpTy = getTypeByID(Record[1]);
1158        if (!OpTy) return Error("Invalid CE_CAST record");
1159        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
1160        V = ConstantExpr::getCast(Opc, Op, CurTy);
1161      }
1162      break;
1163    }
1164    case bitc::CST_CODE_CE_INBOUNDS_GEP:
1165    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
1166      if (Record.size() & 1) return Error("Invalid CE_GEP record");
1167      SmallVector<Constant*, 16> Elts;
1168      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
1169        Type *ElTy = getTypeByID(Record[i]);
1170        if (!ElTy) return Error("Invalid CE_GEP record");
1171        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
1172      }
1173      ArrayRef<Constant *> Indices(Elts.begin() + 1, Elts.end());
1174      V = ConstantExpr::getGetElementPtr(Elts[0], Indices,
1175                                         BitCode ==
1176                                           bitc::CST_CODE_CE_INBOUNDS_GEP);
1177      break;
1178    }
1179    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
1180      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
1181      V = ConstantExpr::getSelect(
1182                          ValueList.getConstantFwdRef(Record[0],
1183                                                      Type::getInt1Ty(Context)),
1184                          ValueList.getConstantFwdRef(Record[1],CurTy),
1185                          ValueList.getConstantFwdRef(Record[2],CurTy));
1186      break;
1187    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
1188      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
1189      VectorType *OpTy =
1190        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1191      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
1192      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1193      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
1194                                                  Type::getInt32Ty(Context));
1195      V = ConstantExpr::getExtractElement(Op0, Op1);
1196      break;
1197    }
1198    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
1199      VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1200      if (Record.size() < 3 || OpTy == 0)
1201        return Error("Invalid CE_INSERTELT record");
1202      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1203      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
1204                                                  OpTy->getElementType());
1205      Constant *Op2 = ValueList.getConstantFwdRef(Record[2],
1206                                                  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      // FIXME: Remove in 4.0.
1565      std::string S;
1566      if (ConvertToString(Record, 0, S))
1567        return Error("Invalid MODULE_CODE_DEPLIB record");
1568      // Ignore value.
1569      break;
1570    }
1571    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
1572      std::string S;
1573      if (ConvertToString(Record, 0, S))
1574        return Error("Invalid MODULE_CODE_SECTIONNAME record");
1575      SectionTable.push_back(S);
1576      break;
1577    }
1578    case bitc::MODULE_CODE_GCNAME: {  // SECTIONNAME: [strchr x N]
1579      std::string S;
1580      if (ConvertToString(Record, 0, S))
1581        return Error("Invalid MODULE_CODE_GCNAME record");
1582      GCTable.push_back(S);
1583      break;
1584    }
1585    // GLOBALVAR: [pointer type, isconst, initid,
1586    //             linkage, alignment, section, visibility, threadlocal,
1587    //             unnamed_addr]
1588    case bitc::MODULE_CODE_GLOBALVAR: {
1589      if (Record.size() < 6)
1590        return Error("Invalid MODULE_CODE_GLOBALVAR record");
1591      Type *Ty = getTypeByID(Record[0]);
1592      if (!Ty) return Error("Invalid MODULE_CODE_GLOBALVAR record");
1593      if (!Ty->isPointerTy())
1594        return Error("Global not a pointer type!");
1595      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
1596      Ty = cast<PointerType>(Ty)->getElementType();
1597
1598      bool isConstant = Record[1];
1599      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1600      unsigned Alignment = (1 << Record[4]) >> 1;
1601      std::string Section;
1602      if (Record[5]) {
1603        if (Record[5]-1 >= SectionTable.size())
1604          return Error("Invalid section ID");
1605        Section = SectionTable[Record[5]-1];
1606      }
1607      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1608      if (Record.size() > 6)
1609        Visibility = GetDecodedVisibility(Record[6]);
1610
1611      GlobalVariable::ThreadLocalMode TLM = GlobalVariable::NotThreadLocal;
1612      if (Record.size() > 7)
1613        TLM = GetDecodedThreadLocalMode(Record[7]);
1614
1615      bool UnnamedAddr = false;
1616      if (Record.size() > 8)
1617        UnnamedAddr = Record[8];
1618
1619      GlobalVariable *NewGV =
1620        new GlobalVariable(*TheModule, Ty, isConstant, Linkage, 0, "", 0,
1621                           TLM, AddressSpace);
1622      NewGV->setAlignment(Alignment);
1623      if (!Section.empty())
1624        NewGV->setSection(Section);
1625      NewGV->setVisibility(Visibility);
1626      NewGV->setUnnamedAddr(UnnamedAddr);
1627
1628      ValueList.push_back(NewGV);
1629
1630      // Remember which value to use for the global initializer.
1631      if (unsigned InitID = Record[2])
1632        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1633      break;
1634    }
1635    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1636    //             alignment, section, visibility, gc, unnamed_addr]
1637    case bitc::MODULE_CODE_FUNCTION: {
1638      if (Record.size() < 8)
1639        return Error("Invalid MODULE_CODE_FUNCTION record");
1640      Type *Ty = getTypeByID(Record[0]);
1641      if (!Ty) return Error("Invalid MODULE_CODE_FUNCTION record");
1642      if (!Ty->isPointerTy())
1643        return Error("Function not a pointer type!");
1644      FunctionType *FTy =
1645        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1646      if (!FTy)
1647        return Error("Function not a pointer to function type!");
1648
1649      Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
1650                                        "", TheModule);
1651
1652      Func->setCallingConv(static_cast<CallingConv::ID>(Record[1]));
1653      bool isProto = Record[2];
1654      Func->setLinkage(GetDecodedLinkage(Record[3]));
1655      Func->setAttributes(getAttributes(Record[4]));
1656
1657      Func->setAlignment((1 << Record[5]) >> 1);
1658      if (Record[6]) {
1659        if (Record[6]-1 >= SectionTable.size())
1660          return Error("Invalid section ID");
1661        Func->setSection(SectionTable[Record[6]-1]);
1662      }
1663      Func->setVisibility(GetDecodedVisibility(Record[7]));
1664      if (Record.size() > 8 && Record[8]) {
1665        if (Record[8]-1 > GCTable.size())
1666          return Error("Invalid GC ID");
1667        Func->setGC(GCTable[Record[8]-1].c_str());
1668      }
1669      bool UnnamedAddr = false;
1670      if (Record.size() > 9)
1671        UnnamedAddr = Record[9];
1672      Func->setUnnamedAddr(UnnamedAddr);
1673      ValueList.push_back(Func);
1674
1675      // If this is a function with a body, remember the prototype we are
1676      // creating now, so that we can match up the body with them later.
1677      if (!isProto) {
1678        FunctionsWithBodies.push_back(Func);
1679        if (LazyStreamer) DeferredFunctionInfo[Func] = 0;
1680      }
1681      break;
1682    }
1683    // ALIAS: [alias type, aliasee val#, linkage]
1684    // ALIAS: [alias type, aliasee val#, linkage, visibility]
1685    case bitc::MODULE_CODE_ALIAS: {
1686      if (Record.size() < 3)
1687        return Error("Invalid MODULE_ALIAS record");
1688      Type *Ty = getTypeByID(Record[0]);
1689      if (!Ty) return Error("Invalid MODULE_ALIAS record");
1690      if (!Ty->isPointerTy())
1691        return Error("Function not a pointer type!");
1692
1693      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1694                                           "", 0, TheModule);
1695      // Old bitcode files didn't have visibility field.
1696      if (Record.size() > 3)
1697        NewGA->setVisibility(GetDecodedVisibility(Record[3]));
1698      ValueList.push_back(NewGA);
1699      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1700      break;
1701    }
1702    /// MODULE_CODE_PURGEVALS: [numvals]
1703    case bitc::MODULE_CODE_PURGEVALS:
1704      // Trim down the value list to the specified size.
1705      if (Record.size() < 1 || Record[0] > ValueList.size())
1706        return Error("Invalid MODULE_PURGEVALS record");
1707      ValueList.shrinkTo(Record[0]);
1708      break;
1709    }
1710    Record.clear();
1711  }
1712
1713  return Error("Premature end of bitstream");
1714}
1715
1716bool BitcodeReader::ParseBitcodeInto(Module *M) {
1717  TheModule = 0;
1718
1719  if (InitStream()) return true;
1720
1721  // Sniff for the signature.
1722  if (Stream.Read(8) != 'B' ||
1723      Stream.Read(8) != 'C' ||
1724      Stream.Read(4) != 0x0 ||
1725      Stream.Read(4) != 0xC ||
1726      Stream.Read(4) != 0xE ||
1727      Stream.Read(4) != 0xD)
1728    return Error("Invalid bitcode signature");
1729
1730  // We expect a number of well-defined blocks, though we don't necessarily
1731  // need to understand them all.
1732  while (!Stream.AtEndOfStream()) {
1733    unsigned Code = Stream.ReadCode();
1734
1735    if (Code != bitc::ENTER_SUBBLOCK) {
1736
1737      // The ranlib in xcode 4 will align archive members by appending newlines
1738      // to the end of them. If this file size is a multiple of 4 but not 8, we
1739      // have to read and ignore these final 4 bytes :-(
1740      if (Stream.getAbbrevIDWidth() == 2 && Code == 2 &&
1741          Stream.Read(6) == 2 && Stream.Read(24) == 0xa0a0a &&
1742          Stream.AtEndOfStream())
1743        return false;
1744
1745      return Error("Invalid record at top-level");
1746    }
1747
1748    unsigned BlockID = Stream.ReadSubBlockID();
1749
1750    // We only know the MODULE subblock ID.
1751    switch (BlockID) {
1752    case bitc::BLOCKINFO_BLOCK_ID:
1753      if (Stream.ReadBlockInfoBlock())
1754        return Error("Malformed BlockInfoBlock");
1755      break;
1756    case bitc::MODULE_BLOCK_ID:
1757      // Reject multiple MODULE_BLOCK's in a single bitstream.
1758      if (TheModule)
1759        return Error("Multiple MODULE_BLOCKs in same stream");
1760      TheModule = M;
1761      if (ParseModule(false))
1762        return true;
1763      if (LazyStreamer) return false;
1764      break;
1765    default:
1766      if (Stream.SkipBlock())
1767        return Error("Malformed block record");
1768      break;
1769    }
1770  }
1771
1772  return false;
1773}
1774
1775bool BitcodeReader::ParseModuleTriple(std::string &Triple) {
1776  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
1777    return Error("Malformed block record");
1778
1779  SmallVector<uint64_t, 64> Record;
1780
1781  // Read all the records for this module.
1782  while (!Stream.AtEndOfStream()) {
1783    unsigned Code = Stream.ReadCode();
1784    if (Code == bitc::END_BLOCK) {
1785      if (Stream.ReadBlockEnd())
1786        return Error("Error at end of module block");
1787
1788      return false;
1789    }
1790
1791    if (Code == bitc::ENTER_SUBBLOCK) {
1792      switch (Stream.ReadSubBlockID()) {
1793      default:  // Skip unknown content.
1794        if (Stream.SkipBlock())
1795          return Error("Malformed block record");
1796        break;
1797      }
1798      continue;
1799    }
1800
1801    if (Code == bitc::DEFINE_ABBREV) {
1802      Stream.ReadAbbrevRecord();
1803      continue;
1804    }
1805
1806    // Read a record.
1807    switch (Stream.ReadRecord(Code, Record)) {
1808    default: break;  // Default behavior, ignore unknown content.
1809    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1810      std::string S;
1811      if (ConvertToString(Record, 0, S))
1812        return Error("Invalid MODULE_CODE_TRIPLE record");
1813      Triple = S;
1814      break;
1815    }
1816    }
1817    Record.clear();
1818  }
1819
1820  return Error("Premature end of bitstream");
1821}
1822
1823bool BitcodeReader::ParseTriple(std::string &Triple) {
1824  if (InitStream()) return true;
1825
1826  // Sniff for the signature.
1827  if (Stream.Read(8) != 'B' ||
1828      Stream.Read(8) != 'C' ||
1829      Stream.Read(4) != 0x0 ||
1830      Stream.Read(4) != 0xC ||
1831      Stream.Read(4) != 0xE ||
1832      Stream.Read(4) != 0xD)
1833    return Error("Invalid bitcode signature");
1834
1835  // We expect a number of well-defined blocks, though we don't necessarily
1836  // need to understand them all.
1837  while (!Stream.AtEndOfStream()) {
1838    unsigned Code = Stream.ReadCode();
1839
1840    if (Code != bitc::ENTER_SUBBLOCK)
1841      return Error("Invalid record at top-level");
1842
1843    unsigned BlockID = Stream.ReadSubBlockID();
1844
1845    // We only know the MODULE subblock ID.
1846    switch (BlockID) {
1847    case bitc::MODULE_BLOCK_ID:
1848      if (ParseModuleTriple(Triple))
1849        return true;
1850      break;
1851    default:
1852      if (Stream.SkipBlock())
1853        return Error("Malformed block record");
1854      break;
1855    }
1856  }
1857
1858  return false;
1859}
1860
1861/// ParseMetadataAttachment - Parse metadata attachments.
1862bool BitcodeReader::ParseMetadataAttachment() {
1863  if (Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
1864    return Error("Malformed block record");
1865
1866  SmallVector<uint64_t, 64> Record;
1867  while(1) {
1868    unsigned Code = Stream.ReadCode();
1869    if (Code == bitc::END_BLOCK) {
1870      if (Stream.ReadBlockEnd())
1871        return Error("Error at end of PARAMATTR block");
1872      break;
1873    }
1874    if (Code == bitc::DEFINE_ABBREV) {
1875      Stream.ReadAbbrevRecord();
1876      continue;
1877    }
1878    // Read a metadata attachment record.
1879    Record.clear();
1880    switch (Stream.ReadRecord(Code, Record)) {
1881    default:  // Default behavior: ignore.
1882      break;
1883    case bitc::METADATA_ATTACHMENT: {
1884      unsigned RecordLength = Record.size();
1885      if (Record.empty() || (RecordLength - 1) % 2 == 1)
1886        return Error ("Invalid METADATA_ATTACHMENT reader!");
1887      Instruction *Inst = InstructionList[Record[0]];
1888      for (unsigned i = 1; i != RecordLength; i = i+2) {
1889        unsigned Kind = Record[i];
1890        DenseMap<unsigned, unsigned>::iterator I =
1891          MDKindMap.find(Kind);
1892        if (I == MDKindMap.end())
1893          return Error("Invalid metadata kind ID");
1894        Value *Node = MDValueList.getValueFwdRef(Record[i+1]);
1895        Inst->setMetadata(I->second, cast<MDNode>(Node));
1896      }
1897      break;
1898    }
1899    }
1900  }
1901  return false;
1902}
1903
1904/// ParseFunctionBody - Lazily parse the specified function body block.
1905bool BitcodeReader::ParseFunctionBody(Function *F) {
1906  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1907    return Error("Malformed block record");
1908
1909  InstructionList.clear();
1910  unsigned ModuleValueListSize = ValueList.size();
1911  unsigned ModuleMDValueListSize = MDValueList.size();
1912
1913  // Add all the function arguments to the value table.
1914  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1915    ValueList.push_back(I);
1916
1917  unsigned NextValueNo = ValueList.size();
1918  BasicBlock *CurBB = 0;
1919  unsigned CurBBNo = 0;
1920
1921  DebugLoc LastLoc;
1922
1923  // Read all the records.
1924  SmallVector<uint64_t, 64> Record;
1925  while (1) {
1926    unsigned Code = Stream.ReadCode();
1927    if (Code == bitc::END_BLOCK) {
1928      if (Stream.ReadBlockEnd())
1929        return Error("Error at end of function block");
1930      break;
1931    }
1932
1933    if (Code == bitc::ENTER_SUBBLOCK) {
1934      switch (Stream.ReadSubBlockID()) {
1935      default:  // Skip unknown content.
1936        if (Stream.SkipBlock())
1937          return Error("Malformed block record");
1938        break;
1939      case bitc::CONSTANTS_BLOCK_ID:
1940        if (ParseConstants()) return true;
1941        NextValueNo = ValueList.size();
1942        break;
1943      case bitc::VALUE_SYMTAB_BLOCK_ID:
1944        if (ParseValueSymbolTable()) return true;
1945        break;
1946      case bitc::METADATA_ATTACHMENT_ID:
1947        if (ParseMetadataAttachment()) return true;
1948        break;
1949      case bitc::METADATA_BLOCK_ID:
1950        if (ParseMetadata()) return true;
1951        break;
1952      }
1953      continue;
1954    }
1955
1956    if (Code == bitc::DEFINE_ABBREV) {
1957      Stream.ReadAbbrevRecord();
1958      continue;
1959    }
1960
1961    // Read a record.
1962    Record.clear();
1963    Instruction *I = 0;
1964    unsigned BitCode = Stream.ReadRecord(Code, Record);
1965    switch (BitCode) {
1966    default: // Default behavior: reject
1967      return Error("Unknown instruction");
1968    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1969      if (Record.size() < 1 || Record[0] == 0)
1970        return Error("Invalid DECLAREBLOCKS record");
1971      // Create all the basic blocks for the function.
1972      FunctionBBs.resize(Record[0]);
1973      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1974        FunctionBBs[i] = BasicBlock::Create(Context, "", F);
1975      CurBB = FunctionBBs[0];
1976      continue;
1977
1978    case bitc::FUNC_CODE_DEBUG_LOC_AGAIN:  // DEBUG_LOC_AGAIN
1979      // This record indicates that the last instruction is at the same
1980      // location as the previous instruction with a location.
1981      I = 0;
1982
1983      // Get the last instruction emitted.
1984      if (CurBB && !CurBB->empty())
1985        I = &CurBB->back();
1986      else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
1987               !FunctionBBs[CurBBNo-1]->empty())
1988        I = &FunctionBBs[CurBBNo-1]->back();
1989
1990      if (I == 0) return Error("Invalid DEBUG_LOC_AGAIN record");
1991      I->setDebugLoc(LastLoc);
1992      I = 0;
1993      continue;
1994
1995    case bitc::FUNC_CODE_DEBUG_LOC: {      // DEBUG_LOC: [line, col, scope, ia]
1996      I = 0;     // Get the last instruction emitted.
1997      if (CurBB && !CurBB->empty())
1998        I = &CurBB->back();
1999      else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
2000               !FunctionBBs[CurBBNo-1]->empty())
2001        I = &FunctionBBs[CurBBNo-1]->back();
2002      if (I == 0 || Record.size() < 4)
2003        return Error("Invalid FUNC_CODE_DEBUG_LOC record");
2004
2005      unsigned Line = Record[0], Col = Record[1];
2006      unsigned ScopeID = Record[2], IAID = Record[3];
2007
2008      MDNode *Scope = 0, *IA = 0;
2009      if (ScopeID) Scope = cast<MDNode>(MDValueList.getValueFwdRef(ScopeID-1));
2010      if (IAID)    IA = cast<MDNode>(MDValueList.getValueFwdRef(IAID-1));
2011      LastLoc = DebugLoc::get(Line, Col, Scope, IA);
2012      I->setDebugLoc(LastLoc);
2013      I = 0;
2014      continue;
2015    }
2016
2017    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
2018      unsigned OpNum = 0;
2019      Value *LHS, *RHS;
2020      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
2021          popValue(Record, OpNum, NextValueNo, LHS->getType(), RHS) ||
2022          OpNum+1 > Record.size())
2023        return Error("Invalid BINOP record");
2024
2025      int Opc = GetDecodedBinaryOpcode(Record[OpNum++], LHS->getType());
2026      if (Opc == -1) return Error("Invalid BINOP record");
2027      I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
2028      InstructionList.push_back(I);
2029      if (OpNum < Record.size()) {
2030        if (Opc == Instruction::Add ||
2031            Opc == Instruction::Sub ||
2032            Opc == Instruction::Mul ||
2033            Opc == Instruction::Shl) {
2034          if (Record[OpNum] & (1 << bitc::OBO_NO_SIGNED_WRAP))
2035            cast<BinaryOperator>(I)->setHasNoSignedWrap(true);
2036          if (Record[OpNum] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
2037            cast<BinaryOperator>(I)->setHasNoUnsignedWrap(true);
2038        } else if (Opc == Instruction::SDiv ||
2039                   Opc == Instruction::UDiv ||
2040                   Opc == Instruction::LShr ||
2041                   Opc == Instruction::AShr) {
2042          if (Record[OpNum] & (1 << bitc::PEO_EXACT))
2043            cast<BinaryOperator>(I)->setIsExact(true);
2044        } else if (isa<FPMathOperator>(I)) {
2045          FastMathFlags FMF;
2046          if (0 != (Record[OpNum] & FastMathFlags::UnsafeAlgebra))
2047            FMF.setUnsafeAlgebra();
2048          if (0 != (Record[OpNum] & FastMathFlags::NoNaNs))
2049            FMF.setNoNaNs();
2050          if (0 != (Record[OpNum] & FastMathFlags::NoInfs))
2051            FMF.setNoInfs();
2052          if (0 != (Record[OpNum] & FastMathFlags::NoSignedZeros))
2053            FMF.setNoSignedZeros();
2054          if (0 != (Record[OpNum] & FastMathFlags::AllowReciprocal))
2055            FMF.setAllowReciprocal();
2056          if (FMF.any())
2057            I->setFastMathFlags(FMF);
2058        }
2059
2060      }
2061      break;
2062    }
2063    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
2064      unsigned OpNum = 0;
2065      Value *Op;
2066      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2067          OpNum+2 != Record.size())
2068        return Error("Invalid CAST record");
2069
2070      Type *ResTy = getTypeByID(Record[OpNum]);
2071      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
2072      if (Opc == -1 || ResTy == 0)
2073        return Error("Invalid CAST record");
2074      I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
2075      InstructionList.push_back(I);
2076      break;
2077    }
2078    case bitc::FUNC_CODE_INST_INBOUNDS_GEP:
2079    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
2080      unsigned OpNum = 0;
2081      Value *BasePtr;
2082      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
2083        return Error("Invalid GEP record");
2084
2085      SmallVector<Value*, 16> GEPIdx;
2086      while (OpNum != Record.size()) {
2087        Value *Op;
2088        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2089          return Error("Invalid GEP record");
2090        GEPIdx.push_back(Op);
2091      }
2092
2093      I = GetElementPtrInst::Create(BasePtr, GEPIdx);
2094      InstructionList.push_back(I);
2095      if (BitCode == bitc::FUNC_CODE_INST_INBOUNDS_GEP)
2096        cast<GetElementPtrInst>(I)->setIsInBounds(true);
2097      break;
2098    }
2099
2100    case bitc::FUNC_CODE_INST_EXTRACTVAL: {
2101                                       // EXTRACTVAL: [opty, opval, n x indices]
2102      unsigned OpNum = 0;
2103      Value *Agg;
2104      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2105        return Error("Invalid EXTRACTVAL record");
2106
2107      SmallVector<unsigned, 4> EXTRACTVALIdx;
2108      for (unsigned RecSize = Record.size();
2109           OpNum != RecSize; ++OpNum) {
2110        uint64_t Index = Record[OpNum];
2111        if ((unsigned)Index != Index)
2112          return Error("Invalid EXTRACTVAL index");
2113        EXTRACTVALIdx.push_back((unsigned)Index);
2114      }
2115
2116      I = ExtractValueInst::Create(Agg, EXTRACTVALIdx);
2117      InstructionList.push_back(I);
2118      break;
2119    }
2120
2121    case bitc::FUNC_CODE_INST_INSERTVAL: {
2122                           // INSERTVAL: [opty, opval, opty, opval, n x indices]
2123      unsigned OpNum = 0;
2124      Value *Agg;
2125      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2126        return Error("Invalid INSERTVAL record");
2127      Value *Val;
2128      if (getValueTypePair(Record, OpNum, NextValueNo, Val))
2129        return Error("Invalid INSERTVAL record");
2130
2131      SmallVector<unsigned, 4> INSERTVALIdx;
2132      for (unsigned RecSize = Record.size();
2133           OpNum != RecSize; ++OpNum) {
2134        uint64_t Index = Record[OpNum];
2135        if ((unsigned)Index != Index)
2136          return Error("Invalid INSERTVAL index");
2137        INSERTVALIdx.push_back((unsigned)Index);
2138      }
2139
2140      I = InsertValueInst::Create(Agg, Val, INSERTVALIdx);
2141      InstructionList.push_back(I);
2142      break;
2143    }
2144
2145    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
2146      // obsolete form of select
2147      // handles select i1 ... in old bitcode
2148      unsigned OpNum = 0;
2149      Value *TrueVal, *FalseVal, *Cond;
2150      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2151          popValue(Record, OpNum, NextValueNo, TrueVal->getType(), FalseVal) ||
2152          popValue(Record, OpNum, NextValueNo, Type::getInt1Ty(Context), Cond))
2153        return Error("Invalid SELECT record");
2154
2155      I = SelectInst::Create(Cond, TrueVal, FalseVal);
2156      InstructionList.push_back(I);
2157      break;
2158    }
2159
2160    case bitc::FUNC_CODE_INST_VSELECT: {// VSELECT: [ty,opval,opval,predty,pred]
2161      // new form of select
2162      // handles select i1 or select [N x i1]
2163      unsigned OpNum = 0;
2164      Value *TrueVal, *FalseVal, *Cond;
2165      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2166          popValue(Record, OpNum, NextValueNo, TrueVal->getType(), FalseVal) ||
2167          getValueTypePair(Record, OpNum, NextValueNo, Cond))
2168        return Error("Invalid SELECT record");
2169
2170      // select condition can be either i1 or [N x i1]
2171      if (VectorType* vector_type =
2172          dyn_cast<VectorType>(Cond->getType())) {
2173        // expect <n x i1>
2174        if (vector_type->getElementType() != Type::getInt1Ty(Context))
2175          return Error("Invalid SELECT condition type");
2176      } else {
2177        // expect i1
2178        if (Cond->getType() != Type::getInt1Ty(Context))
2179          return Error("Invalid SELECT condition type");
2180      }
2181
2182      I = SelectInst::Create(Cond, TrueVal, FalseVal);
2183      InstructionList.push_back(I);
2184      break;
2185    }
2186
2187    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
2188      unsigned OpNum = 0;
2189      Value *Vec, *Idx;
2190      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2191          popValue(Record, OpNum, NextValueNo, Type::getInt32Ty(Context), Idx))
2192        return Error("Invalid EXTRACTELT record");
2193      I = ExtractElementInst::Create(Vec, Idx);
2194      InstructionList.push_back(I);
2195      break;
2196    }
2197
2198    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
2199      unsigned OpNum = 0;
2200      Value *Vec, *Elt, *Idx;
2201      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2202          popValue(Record, OpNum, NextValueNo,
2203                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
2204          popValue(Record, OpNum, NextValueNo, Type::getInt32Ty(Context), Idx))
2205        return Error("Invalid INSERTELT record");
2206      I = InsertElementInst::Create(Vec, Elt, Idx);
2207      InstructionList.push_back(I);
2208      break;
2209    }
2210
2211    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
2212      unsigned OpNum = 0;
2213      Value *Vec1, *Vec2, *Mask;
2214      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
2215          popValue(Record, OpNum, NextValueNo, Vec1->getType(), Vec2))
2216        return Error("Invalid SHUFFLEVEC record");
2217
2218      if (getValueTypePair(Record, OpNum, NextValueNo, Mask))
2219        return Error("Invalid SHUFFLEVEC record");
2220      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
2221      InstructionList.push_back(I);
2222      break;
2223    }
2224
2225    case bitc::FUNC_CODE_INST_CMP:   // CMP: [opty, opval, opval, pred]
2226      // Old form of ICmp/FCmp returning bool
2227      // Existed to differentiate between icmp/fcmp and vicmp/vfcmp which were
2228      // both legal on vectors but had different behaviour.
2229    case bitc::FUNC_CODE_INST_CMP2: { // CMP2: [opty, opval, opval, pred]
2230      // FCmp/ICmp returning bool or vector of bool
2231
2232      unsigned OpNum = 0;
2233      Value *LHS, *RHS;
2234      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
2235          popValue(Record, OpNum, NextValueNo, LHS->getType(), RHS) ||
2236          OpNum+1 != Record.size())
2237        return Error("Invalid CMP record");
2238
2239      if (LHS->getType()->isFPOrFPVectorTy())
2240        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
2241      else
2242        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
2243      InstructionList.push_back(I);
2244      break;
2245    }
2246
2247    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
2248      {
2249        unsigned Size = Record.size();
2250        if (Size == 0) {
2251          I = ReturnInst::Create(Context);
2252          InstructionList.push_back(I);
2253          break;
2254        }
2255
2256        unsigned OpNum = 0;
2257        Value *Op = NULL;
2258        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2259          return Error("Invalid RET record");
2260        if (OpNum != Record.size())
2261          return Error("Invalid RET record");
2262
2263        I = ReturnInst::Create(Context, Op);
2264        InstructionList.push_back(I);
2265        break;
2266      }
2267    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
2268      if (Record.size() != 1 && Record.size() != 3)
2269        return Error("Invalid BR record");
2270      BasicBlock *TrueDest = getBasicBlock(Record[0]);
2271      if (TrueDest == 0)
2272        return Error("Invalid BR record");
2273
2274      if (Record.size() == 1) {
2275        I = BranchInst::Create(TrueDest);
2276        InstructionList.push_back(I);
2277      }
2278      else {
2279        BasicBlock *FalseDest = getBasicBlock(Record[1]);
2280        Value *Cond = getValue(Record, 2, NextValueNo,
2281                               Type::getInt1Ty(Context));
2282        if (FalseDest == 0 || Cond == 0)
2283          return Error("Invalid BR record");
2284        I = BranchInst::Create(TrueDest, FalseDest, Cond);
2285        InstructionList.push_back(I);
2286      }
2287      break;
2288    }
2289    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, op0, op1, ...]
2290      // Check magic
2291      if ((Record[0] >> 16) == SWITCH_INST_MAGIC) {
2292        // New SwitchInst format with case ranges.
2293
2294        Type *OpTy = getTypeByID(Record[1]);
2295        unsigned ValueBitWidth = cast<IntegerType>(OpTy)->getBitWidth();
2296
2297        Value *Cond = getValue(Record, 2, NextValueNo, OpTy);
2298        BasicBlock *Default = getBasicBlock(Record[3]);
2299        if (OpTy == 0 || Cond == 0 || Default == 0)
2300          return Error("Invalid SWITCH record");
2301
2302        unsigned NumCases = Record[4];
2303
2304        SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
2305        InstructionList.push_back(SI);
2306
2307        unsigned CurIdx = 5;
2308        for (unsigned i = 0; i != NumCases; ++i) {
2309          IntegersSubsetToBB CaseBuilder;
2310          unsigned NumItems = Record[CurIdx++];
2311          for (unsigned ci = 0; ci != NumItems; ++ci) {
2312            bool isSingleNumber = Record[CurIdx++];
2313
2314            APInt Low;
2315            unsigned ActiveWords = 1;
2316            if (ValueBitWidth > 64)
2317              ActiveWords = Record[CurIdx++];
2318            Low = ReadWideAPInt(makeArrayRef(&Record[CurIdx], ActiveWords),
2319                                ValueBitWidth);
2320            CurIdx += ActiveWords;
2321
2322            if (!isSingleNumber) {
2323              ActiveWords = 1;
2324              if (ValueBitWidth > 64)
2325                ActiveWords = Record[CurIdx++];
2326              APInt High =
2327                  ReadWideAPInt(makeArrayRef(&Record[CurIdx], ActiveWords),
2328                                ValueBitWidth);
2329
2330              CaseBuilder.add(IntItem::fromType(OpTy, Low),
2331                              IntItem::fromType(OpTy, High));
2332              CurIdx += ActiveWords;
2333            } else
2334              CaseBuilder.add(IntItem::fromType(OpTy, Low));
2335          }
2336          BasicBlock *DestBB = getBasicBlock(Record[CurIdx++]);
2337          IntegersSubset Case = CaseBuilder.getCase();
2338          SI->addCase(Case, DestBB);
2339        }
2340        uint16_t Hash = SI->hash();
2341        if (Hash != (Record[0] & 0xFFFF))
2342          return Error("Invalid SWITCH record");
2343        I = SI;
2344        break;
2345      }
2346
2347      // Old SwitchInst format without case ranges.
2348
2349      if (Record.size() < 3 || (Record.size() & 1) == 0)
2350        return Error("Invalid SWITCH record");
2351      Type *OpTy = getTypeByID(Record[0]);
2352      Value *Cond = getValue(Record, 1, NextValueNo, OpTy);
2353      BasicBlock *Default = getBasicBlock(Record[2]);
2354      if (OpTy == 0 || Cond == 0 || Default == 0)
2355        return Error("Invalid SWITCH record");
2356      unsigned NumCases = (Record.size()-3)/2;
2357      SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
2358      InstructionList.push_back(SI);
2359      for (unsigned i = 0, e = NumCases; i != e; ++i) {
2360        ConstantInt *CaseVal =
2361          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
2362        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
2363        if (CaseVal == 0 || DestBB == 0) {
2364          delete SI;
2365          return Error("Invalid SWITCH record!");
2366        }
2367        SI->addCase(CaseVal, DestBB);
2368      }
2369      I = SI;
2370      break;
2371    }
2372    case bitc::FUNC_CODE_INST_INDIRECTBR: { // INDIRECTBR: [opty, op0, op1, ...]
2373      if (Record.size() < 2)
2374        return Error("Invalid INDIRECTBR record");
2375      Type *OpTy = getTypeByID(Record[0]);
2376      Value *Address = getValue(Record, 1, NextValueNo, OpTy);
2377      if (OpTy == 0 || Address == 0)
2378        return Error("Invalid INDIRECTBR record");
2379      unsigned NumDests = Record.size()-2;
2380      IndirectBrInst *IBI = IndirectBrInst::Create(Address, NumDests);
2381      InstructionList.push_back(IBI);
2382      for (unsigned i = 0, e = NumDests; i != e; ++i) {
2383        if (BasicBlock *DestBB = getBasicBlock(Record[2+i])) {
2384          IBI->addDestination(DestBB);
2385        } else {
2386          delete IBI;
2387          return Error("Invalid INDIRECTBR record!");
2388        }
2389      }
2390      I = IBI;
2391      break;
2392    }
2393
2394    case bitc::FUNC_CODE_INST_INVOKE: {
2395      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
2396      if (Record.size() < 4) return Error("Invalid INVOKE record");
2397      AttributeSet PAL = getAttributes(Record[0]);
2398      unsigned CCInfo = Record[1];
2399      BasicBlock *NormalBB = getBasicBlock(Record[2]);
2400      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
2401
2402      unsigned OpNum = 4;
2403      Value *Callee;
2404      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
2405        return Error("Invalid INVOKE record");
2406
2407      PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
2408      FunctionType *FTy = !CalleeTy ? 0 :
2409        dyn_cast<FunctionType>(CalleeTy->getElementType());
2410
2411      // Check that the right number of fixed parameters are here.
2412      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
2413          Record.size() < OpNum+FTy->getNumParams())
2414        return Error("Invalid INVOKE record");
2415
2416      SmallVector<Value*, 16> Ops;
2417      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
2418        Ops.push_back(getValue(Record, OpNum, NextValueNo,
2419                               FTy->getParamType(i)));
2420        if (Ops.back() == 0) return Error("Invalid INVOKE record");
2421      }
2422
2423      if (!FTy->isVarArg()) {
2424        if (Record.size() != OpNum)
2425          return Error("Invalid INVOKE record");
2426      } else {
2427        // Read type/value pairs for varargs params.
2428        while (OpNum != Record.size()) {
2429          Value *Op;
2430          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2431            return Error("Invalid INVOKE record");
2432          Ops.push_back(Op);
2433        }
2434      }
2435
2436      I = InvokeInst::Create(Callee, NormalBB, UnwindBB, Ops);
2437      InstructionList.push_back(I);
2438      cast<InvokeInst>(I)->setCallingConv(
2439        static_cast<CallingConv::ID>(CCInfo));
2440      cast<InvokeInst>(I)->setAttributes(PAL);
2441      break;
2442    }
2443    case bitc::FUNC_CODE_INST_RESUME: { // RESUME: [opval]
2444      unsigned Idx = 0;
2445      Value *Val = 0;
2446      if (getValueTypePair(Record, Idx, NextValueNo, Val))
2447        return Error("Invalid RESUME record");
2448      I = ResumeInst::Create(Val);
2449      InstructionList.push_back(I);
2450      break;
2451    }
2452    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
2453      I = new UnreachableInst(Context);
2454      InstructionList.push_back(I);
2455      break;
2456    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
2457      if (Record.size() < 1 || ((Record.size()-1)&1))
2458        return Error("Invalid PHI record");
2459      Type *Ty = getTypeByID(Record[0]);
2460      if (!Ty) return Error("Invalid PHI record");
2461
2462      PHINode *PN = PHINode::Create(Ty, (Record.size()-1)/2);
2463      InstructionList.push_back(PN);
2464
2465      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
2466        Value *V;
2467        // With the new function encoding, it is possible that operands have
2468        // negative IDs (for forward references).  Use a signed VBR
2469        // representation to keep the encoding small.
2470        if (UseRelativeIDs)
2471          V = getValueSigned(Record, 1+i, NextValueNo, Ty);
2472        else
2473          V = getValue(Record, 1+i, NextValueNo, Ty);
2474        BasicBlock *BB = getBasicBlock(Record[2+i]);
2475        if (!V || !BB) return Error("Invalid PHI record");
2476        PN->addIncoming(V, BB);
2477      }
2478      I = PN;
2479      break;
2480    }
2481
2482    case bitc::FUNC_CODE_INST_LANDINGPAD: {
2483      // LANDINGPAD: [ty, val, val, num, (id0,val0 ...)?]
2484      unsigned Idx = 0;
2485      if (Record.size() < 4)
2486        return Error("Invalid LANDINGPAD record");
2487      Type *Ty = getTypeByID(Record[Idx++]);
2488      if (!Ty) return Error("Invalid LANDINGPAD record");
2489      Value *PersFn = 0;
2490      if (getValueTypePair(Record, Idx, NextValueNo, PersFn))
2491        return Error("Invalid LANDINGPAD record");
2492
2493      bool IsCleanup = !!Record[Idx++];
2494      unsigned NumClauses = Record[Idx++];
2495      LandingPadInst *LP = LandingPadInst::Create(Ty, PersFn, NumClauses);
2496      LP->setCleanup(IsCleanup);
2497      for (unsigned J = 0; J != NumClauses; ++J) {
2498        LandingPadInst::ClauseType CT =
2499          LandingPadInst::ClauseType(Record[Idx++]); (void)CT;
2500        Value *Val;
2501
2502        if (getValueTypePair(Record, Idx, NextValueNo, Val)) {
2503          delete LP;
2504          return Error("Invalid LANDINGPAD record");
2505        }
2506
2507        assert((CT != LandingPadInst::Catch ||
2508                !isa<ArrayType>(Val->getType())) &&
2509               "Catch clause has a invalid type!");
2510        assert((CT != LandingPadInst::Filter ||
2511                isa<ArrayType>(Val->getType())) &&
2512               "Filter clause has invalid type!");
2513        LP->addClause(Val);
2514      }
2515
2516      I = LP;
2517      InstructionList.push_back(I);
2518      break;
2519    }
2520
2521    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, opty, op, align]
2522      if (Record.size() != 4)
2523        return Error("Invalid ALLOCA record");
2524      PointerType *Ty =
2525        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
2526      Type *OpTy = getTypeByID(Record[1]);
2527      Value *Size = getFnValueByID(Record[2], OpTy);
2528      unsigned Align = Record[3];
2529      if (!Ty || !Size) return Error("Invalid ALLOCA record");
2530      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
2531      InstructionList.push_back(I);
2532      break;
2533    }
2534    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
2535      unsigned OpNum = 0;
2536      Value *Op;
2537      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2538          OpNum+2 != Record.size())
2539        return Error("Invalid LOAD record");
2540
2541      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
2542      InstructionList.push_back(I);
2543      break;
2544    }
2545    case bitc::FUNC_CODE_INST_LOADATOMIC: {
2546       // LOADATOMIC: [opty, op, align, vol, ordering, synchscope]
2547      unsigned OpNum = 0;
2548      Value *Op;
2549      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2550          OpNum+4 != Record.size())
2551        return Error("Invalid LOADATOMIC record");
2552
2553
2554      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2555      if (Ordering == NotAtomic || Ordering == Release ||
2556          Ordering == AcquireRelease)
2557        return Error("Invalid LOADATOMIC record");
2558      if (Ordering != NotAtomic && Record[OpNum] == 0)
2559        return Error("Invalid LOADATOMIC record");
2560      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2561
2562      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1,
2563                       Ordering, SynchScope);
2564      InstructionList.push_back(I);
2565      break;
2566    }
2567    case bitc::FUNC_CODE_INST_STORE: { // STORE2:[ptrty, ptr, val, align, vol]
2568      unsigned OpNum = 0;
2569      Value *Val, *Ptr;
2570      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2571          popValue(Record, OpNum, NextValueNo,
2572                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2573          OpNum+2 != Record.size())
2574        return Error("Invalid STORE record");
2575
2576      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
2577      InstructionList.push_back(I);
2578      break;
2579    }
2580    case bitc::FUNC_CODE_INST_STOREATOMIC: {
2581      // STOREATOMIC: [ptrty, ptr, val, align, vol, ordering, synchscope]
2582      unsigned OpNum = 0;
2583      Value *Val, *Ptr;
2584      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2585          popValue(Record, OpNum, NextValueNo,
2586                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2587          OpNum+4 != Record.size())
2588        return Error("Invalid STOREATOMIC record");
2589
2590      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2591      if (Ordering == NotAtomic || Ordering == Acquire ||
2592          Ordering == AcquireRelease)
2593        return Error("Invalid STOREATOMIC record");
2594      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2595      if (Ordering != NotAtomic && Record[OpNum] == 0)
2596        return Error("Invalid STOREATOMIC record");
2597
2598      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1,
2599                        Ordering, SynchScope);
2600      InstructionList.push_back(I);
2601      break;
2602    }
2603    case bitc::FUNC_CODE_INST_CMPXCHG: {
2604      // CMPXCHG:[ptrty, ptr, cmp, new, vol, ordering, synchscope]
2605      unsigned OpNum = 0;
2606      Value *Ptr, *Cmp, *New;
2607      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2608          popValue(Record, OpNum, NextValueNo,
2609                    cast<PointerType>(Ptr->getType())->getElementType(), Cmp) ||
2610          popValue(Record, OpNum, NextValueNo,
2611                    cast<PointerType>(Ptr->getType())->getElementType(), New) ||
2612          OpNum+3 != Record.size())
2613        return Error("Invalid CMPXCHG record");
2614      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+1]);
2615      if (Ordering == NotAtomic || Ordering == Unordered)
2616        return Error("Invalid CMPXCHG record");
2617      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+2]);
2618      I = new AtomicCmpXchgInst(Ptr, Cmp, New, Ordering, SynchScope);
2619      cast<AtomicCmpXchgInst>(I)->setVolatile(Record[OpNum]);
2620      InstructionList.push_back(I);
2621      break;
2622    }
2623    case bitc::FUNC_CODE_INST_ATOMICRMW: {
2624      // ATOMICRMW:[ptrty, ptr, val, op, vol, ordering, synchscope]
2625      unsigned OpNum = 0;
2626      Value *Ptr, *Val;
2627      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2628          popValue(Record, OpNum, NextValueNo,
2629                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2630          OpNum+4 != Record.size())
2631        return Error("Invalid ATOMICRMW record");
2632      AtomicRMWInst::BinOp Operation = GetDecodedRMWOperation(Record[OpNum]);
2633      if (Operation < AtomicRMWInst::FIRST_BINOP ||
2634          Operation > AtomicRMWInst::LAST_BINOP)
2635        return Error("Invalid ATOMICRMW record");
2636      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2637      if (Ordering == NotAtomic || Ordering == Unordered)
2638        return Error("Invalid ATOMICRMW record");
2639      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2640      I = new AtomicRMWInst(Operation, Ptr, Val, Ordering, SynchScope);
2641      cast<AtomicRMWInst>(I)->setVolatile(Record[OpNum+1]);
2642      InstructionList.push_back(I);
2643      break;
2644    }
2645    case bitc::FUNC_CODE_INST_FENCE: { // FENCE:[ordering, synchscope]
2646      if (2 != Record.size())
2647        return Error("Invalid FENCE record");
2648      AtomicOrdering Ordering = GetDecodedOrdering(Record[0]);
2649      if (Ordering == NotAtomic || Ordering == Unordered ||
2650          Ordering == Monotonic)
2651        return Error("Invalid FENCE record");
2652      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[1]);
2653      I = new FenceInst(Context, Ordering, SynchScope);
2654      InstructionList.push_back(I);
2655      break;
2656    }
2657    case bitc::FUNC_CODE_INST_CALL: {
2658      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
2659      if (Record.size() < 3)
2660        return Error("Invalid CALL record");
2661
2662      AttributeSet PAL = getAttributes(Record[0]);
2663      unsigned CCInfo = Record[1];
2664
2665      unsigned OpNum = 2;
2666      Value *Callee;
2667      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
2668        return Error("Invalid CALL record");
2669
2670      PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
2671      FunctionType *FTy = 0;
2672      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
2673      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
2674        return Error("Invalid CALL record");
2675
2676      SmallVector<Value*, 16> Args;
2677      // Read the fixed params.
2678      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
2679        if (FTy->getParamType(i)->isLabelTy())
2680          Args.push_back(getBasicBlock(Record[OpNum]));
2681        else
2682          Args.push_back(getValue(Record, OpNum, NextValueNo,
2683                                  FTy->getParamType(i)));
2684        if (Args.back() == 0) return Error("Invalid CALL record");
2685      }
2686
2687      // Read type/value pairs for varargs params.
2688      if (!FTy->isVarArg()) {
2689        if (OpNum != Record.size())
2690          return Error("Invalid CALL record");
2691      } else {
2692        while (OpNum != Record.size()) {
2693          Value *Op;
2694          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2695            return Error("Invalid CALL record");
2696          Args.push_back(Op);
2697        }
2698      }
2699
2700      I = CallInst::Create(Callee, Args);
2701      InstructionList.push_back(I);
2702      cast<CallInst>(I)->setCallingConv(
2703        static_cast<CallingConv::ID>(CCInfo>>1));
2704      cast<CallInst>(I)->setTailCall(CCInfo & 1);
2705      cast<CallInst>(I)->setAttributes(PAL);
2706      break;
2707    }
2708    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
2709      if (Record.size() < 3)
2710        return Error("Invalid VAARG record");
2711      Type *OpTy = getTypeByID(Record[0]);
2712      Value *Op = getValue(Record, 1, NextValueNo, OpTy);
2713      Type *ResTy = getTypeByID(Record[2]);
2714      if (!OpTy || !Op || !ResTy)
2715        return Error("Invalid VAARG record");
2716      I = new VAArgInst(Op, ResTy);
2717      InstructionList.push_back(I);
2718      break;
2719    }
2720    }
2721
2722    // Add instruction to end of current BB.  If there is no current BB, reject
2723    // this file.
2724    if (CurBB == 0) {
2725      delete I;
2726      return Error("Invalid instruction with no BB");
2727    }
2728    CurBB->getInstList().push_back(I);
2729
2730    // If this was a terminator instruction, move to the next block.
2731    if (isa<TerminatorInst>(I)) {
2732      ++CurBBNo;
2733      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
2734    }
2735
2736    // Non-void values get registered in the value table for future use.
2737    if (I && !I->getType()->isVoidTy())
2738      ValueList.AssignValue(I, NextValueNo++);
2739  }
2740
2741  // Check the function list for unresolved values.
2742  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
2743    if (A->getParent() == 0) {
2744      // We found at least one unresolved value.  Nuke them all to avoid leaks.
2745      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
2746        if ((A = dyn_cast<Argument>(ValueList[i])) && A->getParent() == 0) {
2747          A->replaceAllUsesWith(UndefValue::get(A->getType()));
2748          delete A;
2749        }
2750      }
2751      return Error("Never resolved value found in function!");
2752    }
2753  }
2754
2755  // FIXME: Check for unresolved forward-declared metadata references
2756  // and clean up leaks.
2757
2758  // See if anything took the address of blocks in this function.  If so,
2759  // resolve them now.
2760  DenseMap<Function*, std::vector<BlockAddrRefTy> >::iterator BAFRI =
2761    BlockAddrFwdRefs.find(F);
2762  if (BAFRI != BlockAddrFwdRefs.end()) {
2763    std::vector<BlockAddrRefTy> &RefList = BAFRI->second;
2764    for (unsigned i = 0, e = RefList.size(); i != e; ++i) {
2765      unsigned BlockIdx = RefList[i].first;
2766      if (BlockIdx >= FunctionBBs.size())
2767        return Error("Invalid blockaddress block #");
2768
2769      GlobalVariable *FwdRef = RefList[i].second;
2770      FwdRef->replaceAllUsesWith(BlockAddress::get(F, FunctionBBs[BlockIdx]));
2771      FwdRef->eraseFromParent();
2772    }
2773
2774    BlockAddrFwdRefs.erase(BAFRI);
2775  }
2776
2777  // Trim the value list down to the size it was before we parsed this function.
2778  ValueList.shrinkTo(ModuleValueListSize);
2779  MDValueList.shrinkTo(ModuleMDValueListSize);
2780  std::vector<BasicBlock*>().swap(FunctionBBs);
2781  return false;
2782}
2783
2784/// FindFunctionInStream - Find the function body in the bitcode stream
2785bool BitcodeReader::FindFunctionInStream(Function *F,
2786       DenseMap<Function*, uint64_t>::iterator DeferredFunctionInfoIterator) {
2787  while (DeferredFunctionInfoIterator->second == 0) {
2788    if (Stream.AtEndOfStream())
2789      return Error("Could not find Function in stream");
2790    // ParseModule will parse the next body in the stream and set its
2791    // position in the DeferredFunctionInfo map.
2792    if (ParseModule(true)) return true;
2793  }
2794  return false;
2795}
2796
2797//===----------------------------------------------------------------------===//
2798// GVMaterializer implementation
2799//===----------------------------------------------------------------------===//
2800
2801
2802bool BitcodeReader::isMaterializable(const GlobalValue *GV) const {
2803  if (const Function *F = dyn_cast<Function>(GV)) {
2804    return F->isDeclaration() &&
2805      DeferredFunctionInfo.count(const_cast<Function*>(F));
2806  }
2807  return false;
2808}
2809
2810bool BitcodeReader::Materialize(GlobalValue *GV, std::string *ErrInfo) {
2811  Function *F = dyn_cast<Function>(GV);
2812  // If it's not a function or is already material, ignore the request.
2813  if (!F || !F->isMaterializable()) return false;
2814
2815  DenseMap<Function*, uint64_t>::iterator DFII = DeferredFunctionInfo.find(F);
2816  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
2817  // If its position is recorded as 0, its body is somewhere in the stream
2818  // but we haven't seen it yet.
2819  if (DFII->second == 0)
2820    if (LazyStreamer && FindFunctionInStream(F, DFII)) return true;
2821
2822  // Move the bit stream to the saved position of the deferred function body.
2823  Stream.JumpToBit(DFII->second);
2824
2825  if (ParseFunctionBody(F)) {
2826    if (ErrInfo) *ErrInfo = ErrorString;
2827    return true;
2828  }
2829
2830  // Upgrade any old intrinsic calls in the function.
2831  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
2832       E = UpgradedIntrinsics.end(); I != E; ++I) {
2833    if (I->first != I->second) {
2834      for (Value::use_iterator UI = I->first->use_begin(),
2835           UE = I->first->use_end(); UI != UE; ) {
2836        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2837          UpgradeIntrinsicCall(CI, I->second);
2838      }
2839    }
2840  }
2841
2842  return false;
2843}
2844
2845bool BitcodeReader::isDematerializable(const GlobalValue *GV) const {
2846  const Function *F = dyn_cast<Function>(GV);
2847  if (!F || F->isDeclaration())
2848    return false;
2849  return DeferredFunctionInfo.count(const_cast<Function*>(F));
2850}
2851
2852void BitcodeReader::Dematerialize(GlobalValue *GV) {
2853  Function *F = dyn_cast<Function>(GV);
2854  // If this function isn't dematerializable, this is a noop.
2855  if (!F || !isDematerializable(F))
2856    return;
2857
2858  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
2859
2860  // Just forget the function body, we can remat it later.
2861  F->deleteBody();
2862}
2863
2864
2865bool BitcodeReader::MaterializeModule(Module *M, std::string *ErrInfo) {
2866  assert(M == TheModule &&
2867         "Can only Materialize the Module this BitcodeReader is attached to.");
2868  // Iterate over the module, deserializing any functions that are still on
2869  // disk.
2870  for (Module::iterator F = TheModule->begin(), E = TheModule->end();
2871       F != E; ++F)
2872    if (F->isMaterializable() &&
2873        Materialize(F, ErrInfo))
2874      return true;
2875
2876  // At this point, if there are any function bodies, the current bit is
2877  // pointing to the END_BLOCK record after them. Now make sure the rest
2878  // of the bits in the module have been read.
2879  if (NextUnreadBit)
2880    ParseModule(true);
2881
2882  // Upgrade any intrinsic calls that slipped through (should not happen!) and
2883  // delete the old functions to clean up. We can't do this unless the entire
2884  // module is materialized because there could always be another function body
2885  // with calls to the old function.
2886  for (std::vector<std::pair<Function*, Function*> >::iterator I =
2887       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
2888    if (I->first != I->second) {
2889      for (Value::use_iterator UI = I->first->use_begin(),
2890           UE = I->first->use_end(); UI != UE; ) {
2891        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2892          UpgradeIntrinsicCall(CI, I->second);
2893      }
2894      if (!I->first->use_empty())
2895        I->first->replaceAllUsesWith(I->second);
2896      I->first->eraseFromParent();
2897    }
2898  }
2899  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
2900
2901  return false;
2902}
2903
2904bool BitcodeReader::InitStream() {
2905  if (LazyStreamer) return InitLazyStream();
2906  return InitStreamFromBuffer();
2907}
2908
2909bool BitcodeReader::InitStreamFromBuffer() {
2910  const unsigned char *BufPtr = (const unsigned char*)Buffer->getBufferStart();
2911  const unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
2912
2913  if (Buffer->getBufferSize() & 3) {
2914    if (!isRawBitcode(BufPtr, BufEnd) && !isBitcodeWrapper(BufPtr, BufEnd))
2915      return Error("Invalid bitcode signature");
2916    else
2917      return Error("Bitcode stream should be a multiple of 4 bytes in length");
2918  }
2919
2920  // If we have a wrapper header, parse it and ignore the non-bc file contents.
2921  // The magic number is 0x0B17C0DE stored in little endian.
2922  if (isBitcodeWrapper(BufPtr, BufEnd))
2923    if (SkipBitcodeWrapperHeader(BufPtr, BufEnd, true))
2924      return Error("Invalid bitcode wrapper header");
2925
2926  StreamFile.reset(new BitstreamReader(BufPtr, BufEnd));
2927  Stream.init(*StreamFile);
2928
2929  return false;
2930}
2931
2932bool BitcodeReader::InitLazyStream() {
2933  // Check and strip off the bitcode wrapper; BitstreamReader expects never to
2934  // see it.
2935  StreamingMemoryObject *Bytes = new StreamingMemoryObject(LazyStreamer);
2936  StreamFile.reset(new BitstreamReader(Bytes));
2937  Stream.init(*StreamFile);
2938
2939  unsigned char buf[16];
2940  if (Bytes->readBytes(0, 16, buf, NULL) == -1)
2941    return Error("Bitcode stream must be at least 16 bytes in length");
2942
2943  if (!isBitcode(buf, buf + 16))
2944    return Error("Invalid bitcode signature");
2945
2946  if (isBitcodeWrapper(buf, buf + 4)) {
2947    const unsigned char *bitcodeStart = buf;
2948    const unsigned char *bitcodeEnd = buf + 16;
2949    SkipBitcodeWrapperHeader(bitcodeStart, bitcodeEnd, false);
2950    Bytes->dropLeadingBytes(bitcodeStart - buf);
2951    Bytes->setKnownObjectSize(bitcodeEnd - bitcodeStart);
2952  }
2953  return false;
2954}
2955
2956//===----------------------------------------------------------------------===//
2957// External interface
2958//===----------------------------------------------------------------------===//
2959
2960/// getLazyBitcodeModule - lazy function-at-a-time loading from a file.
2961///
2962Module *llvm::getLazyBitcodeModule(MemoryBuffer *Buffer,
2963                                   LLVMContext& Context,
2964                                   std::string *ErrMsg) {
2965  Module *M = new Module(Buffer->getBufferIdentifier(), Context);
2966  BitcodeReader *R = new BitcodeReader(Buffer, Context);
2967  M->setMaterializer(R);
2968  if (R->ParseBitcodeInto(M)) {
2969    if (ErrMsg)
2970      *ErrMsg = R->getErrorString();
2971
2972    delete M;  // Also deletes R.
2973    return 0;
2974  }
2975  // Have the BitcodeReader dtor delete 'Buffer'.
2976  R->setBufferOwned(true);
2977
2978  R->materializeForwardReferencedFunctions();
2979
2980  return M;
2981}
2982
2983
2984Module *llvm::getStreamedBitcodeModule(const std::string &name,
2985                                       DataStreamer *streamer,
2986                                       LLVMContext &Context,
2987                                       std::string *ErrMsg) {
2988  Module *M = new Module(name, Context);
2989  BitcodeReader *R = new BitcodeReader(streamer, Context);
2990  M->setMaterializer(R);
2991  if (R->ParseBitcodeInto(M)) {
2992    if (ErrMsg)
2993      *ErrMsg = R->getErrorString();
2994    delete M;  // Also deletes R.
2995    return 0;
2996  }
2997  R->setBufferOwned(false); // no buffer to delete
2998  return M;
2999}
3000
3001/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
3002/// If an error occurs, return null and fill in *ErrMsg if non-null.
3003Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, LLVMContext& Context,
3004                               std::string *ErrMsg){
3005  Module *M = getLazyBitcodeModule(Buffer, Context, ErrMsg);
3006  if (!M) return 0;
3007
3008  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
3009  // there was an error.
3010  static_cast<BitcodeReader*>(M->getMaterializer())->setBufferOwned(false);
3011
3012  // Read in the entire module, and destroy the BitcodeReader.
3013  if (M->MaterializeAllPermanently(ErrMsg)) {
3014    delete M;
3015    return 0;
3016  }
3017
3018  // TODO: Restore the use-lists to the in-memory state when the bitcode was
3019  // written.  We must defer until the Module has been fully materialized.
3020
3021  return M;
3022}
3023
3024std::string llvm::getBitcodeTargetTriple(MemoryBuffer *Buffer,
3025                                         LLVMContext& Context,
3026                                         std::string *ErrMsg) {
3027  BitcodeReader *R = new BitcodeReader(Buffer, Context);
3028  // Don't let the BitcodeReader dtor delete 'Buffer'.
3029  R->setBufferOwned(false);
3030
3031  std::string Triple("");
3032  if (R->ParseTriple(Triple))
3033    if (ErrMsg)
3034      *ErrMsg = R->getErrorString();
3035
3036  delete R;
3037  return Triple;
3038}
3039