BitcodeReader.cpp revision 0a29cb045444c13160e90fe7942a9d7c720185ed 
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    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
445
446    switch (Entry.Kind) {
447    case BitstreamEntry::SubBlock: // Handled for us already.
448    case BitstreamEntry::Error:
449      return Error("Error at end of PARAMATTR block");
450    case BitstreamEntry::EndBlock:
451      return false;
452    case BitstreamEntry::Record:
453      // The interesting case.
454      break;
455    }
456
457    // Read a record.
458    Record.clear();
459    switch (Stream.readRecord(Entry.ID, Record)) {
460    default:  // Default behavior: ignore.
461      break;
462    case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
463      if (Record.size() & 1)
464        return Error("Invalid ENTRY record");
465
466      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
467        Attribute ReconstitutedAttr =
468          Attribute::decodeLLVMAttributesForBitcode(Context, Record[i+1]);
469        Record[i+1] = ReconstitutedAttr.Raw();
470      }
471
472      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
473        AttrBuilder B(Record[i+1]);
474        if (B.hasAttributes())
475          Attrs.push_back(AttributeWithIndex::get(Record[i],
476                                                  Attribute::get(Context, B)));
477      }
478
479      MAttributes.push_back(AttributeSet::get(Context, Attrs));
480      Attrs.clear();
481      break;
482    }
483    }
484  }
485}
486
487bool BitcodeReader::ParseTypeTable() {
488  if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID_NEW))
489    return Error("Malformed block record");
490
491  return ParseTypeTableBody();
492}
493
494bool BitcodeReader::ParseTypeTableBody() {
495  if (!TypeList.empty())
496    return Error("Multiple TYPE_BLOCKs found!");
497
498  SmallVector<uint64_t, 64> Record;
499  unsigned NumRecords = 0;
500
501  SmallString<64> TypeName;
502
503  // Read all the records for this type table.
504  while (1) {
505    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
506
507    switch (Entry.Kind) {
508    case BitstreamEntry::SubBlock: // Handled for us already.
509    case BitstreamEntry::Error:
510      Error("Error in the type table block");
511      return true;
512    case BitstreamEntry::EndBlock:
513      if (NumRecords != TypeList.size())
514        return Error("Invalid type forward reference in TYPE_BLOCK");
515      return false;
516    case BitstreamEntry::Record:
517      // The interesting case.
518      break;
519    }
520
521    // Read a record.
522    Record.clear();
523    Type *ResultTy = 0;
524    switch (Stream.readRecord(Entry.ID, Record)) {
525    default: return Error("unknown type in type table");
526    case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
527      // TYPE_CODE_NUMENTRY contains a count of the number of types in the
528      // type list.  This allows us to reserve space.
529      if (Record.size() < 1)
530        return Error("Invalid TYPE_CODE_NUMENTRY record");
531      TypeList.resize(Record[0]);
532      continue;
533    case bitc::TYPE_CODE_VOID:      // VOID
534      ResultTy = Type::getVoidTy(Context);
535      break;
536    case bitc::TYPE_CODE_HALF:     // HALF
537      ResultTy = Type::getHalfTy(Context);
538      break;
539    case bitc::TYPE_CODE_FLOAT:     // FLOAT
540      ResultTy = Type::getFloatTy(Context);
541      break;
542    case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
543      ResultTy = Type::getDoubleTy(Context);
544      break;
545    case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
546      ResultTy = Type::getX86_FP80Ty(Context);
547      break;
548    case bitc::TYPE_CODE_FP128:     // FP128
549      ResultTy = Type::getFP128Ty(Context);
550      break;
551    case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
552      ResultTy = Type::getPPC_FP128Ty(Context);
553      break;
554    case bitc::TYPE_CODE_LABEL:     // LABEL
555      ResultTy = Type::getLabelTy(Context);
556      break;
557    case bitc::TYPE_CODE_METADATA:  // METADATA
558      ResultTy = Type::getMetadataTy(Context);
559      break;
560    case bitc::TYPE_CODE_X86_MMX:   // X86_MMX
561      ResultTy = Type::getX86_MMXTy(Context);
562      break;
563    case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
564      if (Record.size() < 1)
565        return Error("Invalid Integer type record");
566
567      ResultTy = IntegerType::get(Context, Record[0]);
568      break;
569    case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
570                                    //          [pointee type, address space]
571      if (Record.size() < 1)
572        return Error("Invalid POINTER type record");
573      unsigned AddressSpace = 0;
574      if (Record.size() == 2)
575        AddressSpace = Record[1];
576      ResultTy = getTypeByID(Record[0]);
577      if (ResultTy == 0) return Error("invalid element type in pointer type");
578      ResultTy = PointerType::get(ResultTy, AddressSpace);
579      break;
580    }
581    case bitc::TYPE_CODE_FUNCTION_OLD: {
582      // FIXME: attrid is dead, remove it in LLVM 4.0
583      // FUNCTION: [vararg, attrid, retty, paramty x N]
584      if (Record.size() < 3)
585        return Error("Invalid FUNCTION type record");
586      SmallVector<Type*, 8> ArgTys;
587      for (unsigned i = 3, e = Record.size(); i != e; ++i) {
588        if (Type *T = getTypeByID(Record[i]))
589          ArgTys.push_back(T);
590        else
591          break;
592      }
593
594      ResultTy = getTypeByID(Record[2]);
595      if (ResultTy == 0 || ArgTys.size() < Record.size()-3)
596        return Error("invalid type in function type");
597
598      ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
599      break;
600    }
601    case bitc::TYPE_CODE_FUNCTION: {
602      // FUNCTION: [vararg, retty, paramty x N]
603      if (Record.size() < 2)
604        return Error("Invalid FUNCTION type record");
605      SmallVector<Type*, 8> ArgTys;
606      for (unsigned i = 2, e = Record.size(); i != e; ++i) {
607        if (Type *T = getTypeByID(Record[i]))
608          ArgTys.push_back(T);
609        else
610          break;
611      }
612
613      ResultTy = getTypeByID(Record[1]);
614      if (ResultTy == 0 || ArgTys.size() < Record.size()-2)
615        return Error("invalid type in function type");
616
617      ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
618      break;
619    }
620    case bitc::TYPE_CODE_STRUCT_ANON: {  // STRUCT: [ispacked, eltty x N]
621      if (Record.size() < 1)
622        return Error("Invalid STRUCT type record");
623      SmallVector<Type*, 8> EltTys;
624      for (unsigned i = 1, e = Record.size(); i != e; ++i) {
625        if (Type *T = getTypeByID(Record[i]))
626          EltTys.push_back(T);
627        else
628          break;
629      }
630      if (EltTys.size() != Record.size()-1)
631        return Error("invalid type in struct type");
632      ResultTy = StructType::get(Context, EltTys, Record[0]);
633      break;
634    }
635    case bitc::TYPE_CODE_STRUCT_NAME:   // STRUCT_NAME: [strchr x N]
636      if (ConvertToString(Record, 0, TypeName))
637        return Error("Invalid STRUCT_NAME record");
638      continue;
639
640    case bitc::TYPE_CODE_STRUCT_NAMED: { // STRUCT: [ispacked, eltty x N]
641      if (Record.size() < 1)
642        return Error("Invalid STRUCT type record");
643
644      if (NumRecords >= TypeList.size())
645        return Error("invalid TYPE table");
646
647      // Check to see if this was forward referenced, if so fill in the temp.
648      StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
649      if (Res) {
650        Res->setName(TypeName);
651        TypeList[NumRecords] = 0;
652      } else  // Otherwise, create a new struct.
653        Res = StructType::create(Context, TypeName);
654      TypeName.clear();
655
656      SmallVector<Type*, 8> EltTys;
657      for (unsigned i = 1, e = Record.size(); i != e; ++i) {
658        if (Type *T = getTypeByID(Record[i]))
659          EltTys.push_back(T);
660        else
661          break;
662      }
663      if (EltTys.size() != Record.size()-1)
664        return Error("invalid STRUCT type record");
665      Res->setBody(EltTys, Record[0]);
666      ResultTy = Res;
667      break;
668    }
669    case bitc::TYPE_CODE_OPAQUE: {       // OPAQUE: []
670      if (Record.size() != 1)
671        return Error("Invalid OPAQUE type record");
672
673      if (NumRecords >= TypeList.size())
674        return Error("invalid TYPE table");
675
676      // Check to see if this was forward referenced, if so fill in the temp.
677      StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
678      if (Res) {
679        Res->setName(TypeName);
680        TypeList[NumRecords] = 0;
681      } else  // Otherwise, create a new struct with no body.
682        Res = StructType::create(Context, TypeName);
683      TypeName.clear();
684      ResultTy = Res;
685      break;
686    }
687    case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
688      if (Record.size() < 2)
689        return Error("Invalid ARRAY type record");
690      if ((ResultTy = getTypeByID(Record[1])))
691        ResultTy = ArrayType::get(ResultTy, Record[0]);
692      else
693        return Error("Invalid ARRAY type element");
694      break;
695    case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
696      if (Record.size() < 2)
697        return Error("Invalid VECTOR type record");
698      if ((ResultTy = getTypeByID(Record[1])))
699        ResultTy = VectorType::get(ResultTy, Record[0]);
700      else
701        return Error("Invalid ARRAY type element");
702      break;
703    }
704
705    if (NumRecords >= TypeList.size())
706      return Error("invalid TYPE table");
707    assert(ResultTy && "Didn't read a type?");
708    assert(TypeList[NumRecords] == 0 && "Already read type?");
709    TypeList[NumRecords++] = ResultTy;
710  }
711}
712
713bool BitcodeReader::ParseValueSymbolTable() {
714  if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
715    return Error("Malformed block record");
716
717  SmallVector<uint64_t, 64> Record;
718
719  // Read all the records for this value table.
720  SmallString<128> ValueName;
721  while (1) {
722    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
723
724    switch (Entry.Kind) {
725    case BitstreamEntry::SubBlock: // Handled for us already.
726    case BitstreamEntry::Error:
727      return Error("malformed value symbol table block");
728    case BitstreamEntry::EndBlock:
729      return false;
730    case BitstreamEntry::Record:
731      // The interesting case.
732      break;
733    }
734
735    // Read a record.
736    Record.clear();
737    switch (Stream.readRecord(Entry.ID, Record)) {
738    default:  // Default behavior: unknown type.
739      break;
740    case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
741      if (ConvertToString(Record, 1, ValueName))
742        return Error("Invalid VST_ENTRY record");
743      unsigned ValueID = Record[0];
744      if (ValueID >= ValueList.size())
745        return Error("Invalid Value ID in VST_ENTRY record");
746      Value *V = ValueList[ValueID];
747
748      V->setName(StringRef(ValueName.data(), ValueName.size()));
749      ValueName.clear();
750      break;
751    }
752    case bitc::VST_CODE_BBENTRY: {
753      if (ConvertToString(Record, 1, ValueName))
754        return Error("Invalid VST_BBENTRY record");
755      BasicBlock *BB = getBasicBlock(Record[0]);
756      if (BB == 0)
757        return Error("Invalid BB ID in VST_BBENTRY record");
758
759      BB->setName(StringRef(ValueName.data(), ValueName.size()));
760      ValueName.clear();
761      break;
762    }
763    }
764  }
765}
766
767bool BitcodeReader::ParseMetadata() {
768  unsigned NextMDValueNo = MDValueList.size();
769
770  if (Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
771    return Error("Malformed block record");
772
773  SmallVector<uint64_t, 64> Record;
774
775  // Read all the records.
776  while (1) {
777    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
778
779    switch (Entry.Kind) {
780    case BitstreamEntry::SubBlock: // Handled for us already.
781    case BitstreamEntry::Error:
782      Error("malformed metadata block");
783      return true;
784    case BitstreamEntry::EndBlock:
785      return false;
786    case BitstreamEntry::Record:
787      // The interesting case.
788      break;
789    }
790
791    bool IsFunctionLocal = false;
792    // Read a record.
793    Record.clear();
794    unsigned Code = Stream.readRecord(Entry.ID, Record);
795    switch (Code) {
796    default:  // Default behavior: ignore.
797      break;
798    case bitc::METADATA_NAME: {
799      // Read name of the named metadata.
800      SmallString<8> Name(Record.begin(), Record.end());
801      Record.clear();
802      Code = Stream.ReadCode();
803
804      // METADATA_NAME is always followed by METADATA_NAMED_NODE.
805      unsigned NextBitCode = Stream.readRecord(Code, Record);
806      assert(NextBitCode == bitc::METADATA_NAMED_NODE); (void)NextBitCode;
807
808      // Read named metadata elements.
809      unsigned Size = Record.size();
810      NamedMDNode *NMD = TheModule->getOrInsertNamedMetadata(Name);
811      for (unsigned i = 0; i != Size; ++i) {
812        MDNode *MD = dyn_cast<MDNode>(MDValueList.getValueFwdRef(Record[i]));
813        if (MD == 0)
814          return Error("Malformed metadata record");
815        NMD->addOperand(MD);
816      }
817      break;
818    }
819    case bitc::METADATA_FN_NODE:
820      IsFunctionLocal = true;
821      // fall-through
822    case bitc::METADATA_NODE: {
823      if (Record.size() % 2 == 1)
824        return Error("Invalid METADATA_NODE record");
825
826      unsigned Size = Record.size();
827      SmallVector<Value*, 8> Elts;
828      for (unsigned i = 0; i != Size; i += 2) {
829        Type *Ty = getTypeByID(Record[i]);
830        if (!Ty) return Error("Invalid METADATA_NODE record");
831        if (Ty->isMetadataTy())
832          Elts.push_back(MDValueList.getValueFwdRef(Record[i+1]));
833        else if (!Ty->isVoidTy())
834          Elts.push_back(ValueList.getValueFwdRef(Record[i+1], Ty));
835        else
836          Elts.push_back(NULL);
837      }
838      Value *V = MDNode::getWhenValsUnresolved(Context, Elts, IsFunctionLocal);
839      IsFunctionLocal = false;
840      MDValueList.AssignValue(V, NextMDValueNo++);
841      break;
842    }
843    case bitc::METADATA_STRING: {
844      SmallString<8> String(Record.begin(), Record.end());
845      Value *V = MDString::get(Context, String);
846      MDValueList.AssignValue(V, NextMDValueNo++);
847      break;
848    }
849    case bitc::METADATA_KIND: {
850      if (Record.size() < 2)
851        return Error("Invalid METADATA_KIND record");
852
853      unsigned Kind = Record[0];
854      SmallString<8> Name(Record.begin()+1, Record.end());
855
856      unsigned NewKind = TheModule->getMDKindID(Name.str());
857      if (!MDKindMap.insert(std::make_pair(Kind, NewKind)).second)
858        return Error("Conflicting METADATA_KIND records");
859      break;
860    }
861    }
862  }
863}
864
865/// decodeSignRotatedValue - Decode a signed value stored with the sign bit in
866/// the LSB for dense VBR encoding.
867uint64_t BitcodeReader::decodeSignRotatedValue(uint64_t V) {
868  if ((V & 1) == 0)
869    return V >> 1;
870  if (V != 1)
871    return -(V >> 1);
872  // There is no such thing as -0 with integers.  "-0" really means MININT.
873  return 1ULL << 63;
874}
875
876/// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
877/// values and aliases that we can.
878bool BitcodeReader::ResolveGlobalAndAliasInits() {
879  std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
880  std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
881
882  GlobalInitWorklist.swap(GlobalInits);
883  AliasInitWorklist.swap(AliasInits);
884
885  while (!GlobalInitWorklist.empty()) {
886    unsigned ValID = GlobalInitWorklist.back().second;
887    if (ValID >= ValueList.size()) {
888      // Not ready to resolve this yet, it requires something later in the file.
889      GlobalInits.push_back(GlobalInitWorklist.back());
890    } else {
891      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
892        GlobalInitWorklist.back().first->setInitializer(C);
893      else
894        return Error("Global variable initializer is not a constant!");
895    }
896    GlobalInitWorklist.pop_back();
897  }
898
899  while (!AliasInitWorklist.empty()) {
900    unsigned ValID = AliasInitWorklist.back().second;
901    if (ValID >= ValueList.size()) {
902      AliasInits.push_back(AliasInitWorklist.back());
903    } else {
904      if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
905        AliasInitWorklist.back().first->setAliasee(C);
906      else
907        return Error("Alias initializer is not a constant!");
908    }
909    AliasInitWorklist.pop_back();
910  }
911  return false;
912}
913
914static APInt ReadWideAPInt(ArrayRef<uint64_t> Vals, unsigned TypeBits) {
915  SmallVector<uint64_t, 8> Words(Vals.size());
916  std::transform(Vals.begin(), Vals.end(), Words.begin(),
917                 BitcodeReader::decodeSignRotatedValue);
918
919  return APInt(TypeBits, Words);
920}
921
922bool BitcodeReader::ParseConstants() {
923  if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
924    return Error("Malformed block record");
925
926  SmallVector<uint64_t, 64> Record;
927
928  // Read all the records for this value table.
929  Type *CurTy = Type::getInt32Ty(Context);
930  unsigned NextCstNo = ValueList.size();
931  while (1) {
932    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
933
934    switch (Entry.Kind) {
935    case BitstreamEntry::SubBlock: // Handled for us already.
936    case BitstreamEntry::Error:
937      return Error("malformed block record in AST file");
938    case BitstreamEntry::EndBlock:
939      if (NextCstNo != ValueList.size())
940        return Error("Invalid constant reference!");
941
942      // Once all the constants have been read, go through and resolve forward
943      // references.
944      ValueList.ResolveConstantForwardRefs();
945      return false;
946    case BitstreamEntry::Record:
947      // The interesting case.
948      break;
949    }
950
951    // Read a record.
952    Record.clear();
953    Value *V = 0;
954    unsigned BitCode = Stream.readRecord(Entry.ID, Record);
955    switch (BitCode) {
956    default:  // Default behavior: unknown constant
957    case bitc::CST_CODE_UNDEF:     // UNDEF
958      V = UndefValue::get(CurTy);
959      break;
960    case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
961      if (Record.empty())
962        return Error("Malformed CST_SETTYPE record");
963      if (Record[0] >= TypeList.size())
964        return Error("Invalid Type ID in CST_SETTYPE record");
965      CurTy = TypeList[Record[0]];
966      continue;  // Skip the ValueList manipulation.
967    case bitc::CST_CODE_NULL:      // NULL
968      V = Constant::getNullValue(CurTy);
969      break;
970    case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
971      if (!CurTy->isIntegerTy() || Record.empty())
972        return Error("Invalid CST_INTEGER record");
973      V = ConstantInt::get(CurTy, decodeSignRotatedValue(Record[0]));
974      break;
975    case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
976      if (!CurTy->isIntegerTy() || Record.empty())
977        return Error("Invalid WIDE_INTEGER record");
978
979      APInt VInt = ReadWideAPInt(Record,
980                                 cast<IntegerType>(CurTy)->getBitWidth());
981      V = ConstantInt::get(Context, VInt);
982
983      break;
984    }
985    case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
986      if (Record.empty())
987        return Error("Invalid FLOAT record");
988      if (CurTy->isHalfTy())
989        V = ConstantFP::get(Context, APFloat(APFloat::IEEEhalf,
990                                             APInt(16, (uint16_t)Record[0])));
991      else if (CurTy->isFloatTy())
992        V = ConstantFP::get(Context, APFloat(APFloat::IEEEsingle,
993                                             APInt(32, (uint32_t)Record[0])));
994      else if (CurTy->isDoubleTy())
995        V = ConstantFP::get(Context, APFloat(APFloat::IEEEdouble,
996                                             APInt(64, Record[0])));
997      else if (CurTy->isX86_FP80Ty()) {
998        // Bits are not stored the same way as a normal i80 APInt, compensate.
999        uint64_t Rearrange[2];
1000        Rearrange[0] = (Record[1] & 0xffffLL) | (Record[0] << 16);
1001        Rearrange[1] = Record[0] >> 48;
1002        V = ConstantFP::get(Context, APFloat(APFloat::x87DoubleExtended,
1003                                             APInt(80, Rearrange)));
1004      } else if (CurTy->isFP128Ty())
1005        V = ConstantFP::get(Context, APFloat(APFloat::IEEEquad,
1006                                             APInt(128, Record)));
1007      else if (CurTy->isPPC_FP128Ty())
1008        V = ConstantFP::get(Context, APFloat(APFloat::PPCDoubleDouble,
1009                                             APInt(128, Record)));
1010      else
1011        V = UndefValue::get(CurTy);
1012      break;
1013    }
1014
1015    case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
1016      if (Record.empty())
1017        return Error("Invalid CST_AGGREGATE record");
1018
1019      unsigned Size = Record.size();
1020      SmallVector<Constant*, 16> Elts;
1021
1022      if (StructType *STy = dyn_cast<StructType>(CurTy)) {
1023        for (unsigned i = 0; i != Size; ++i)
1024          Elts.push_back(ValueList.getConstantFwdRef(Record[i],
1025                                                     STy->getElementType(i)));
1026        V = ConstantStruct::get(STy, Elts);
1027      } else if (ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
1028        Type *EltTy = ATy->getElementType();
1029        for (unsigned i = 0; i != Size; ++i)
1030          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1031        V = ConstantArray::get(ATy, Elts);
1032      } else if (VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
1033        Type *EltTy = VTy->getElementType();
1034        for (unsigned i = 0; i != Size; ++i)
1035          Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1036        V = ConstantVector::get(Elts);
1037      } else {
1038        V = UndefValue::get(CurTy);
1039      }
1040      break;
1041    }
1042    case bitc::CST_CODE_STRING:    // STRING: [values]
1043    case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
1044      if (Record.empty())
1045        return Error("Invalid CST_STRING record");
1046
1047      SmallString<16> Elts(Record.begin(), Record.end());
1048      V = ConstantDataArray::getString(Context, Elts,
1049                                       BitCode == bitc::CST_CODE_CSTRING);
1050      break;
1051    }
1052    case bitc::CST_CODE_DATA: {// DATA: [n x value]
1053      if (Record.empty())
1054        return Error("Invalid CST_DATA record");
1055
1056      Type *EltTy = cast<SequentialType>(CurTy)->getElementType();
1057      unsigned Size = Record.size();
1058
1059      if (EltTy->isIntegerTy(8)) {
1060        SmallVector<uint8_t, 16> Elts(Record.begin(), Record.end());
1061        if (isa<VectorType>(CurTy))
1062          V = ConstantDataVector::get(Context, Elts);
1063        else
1064          V = ConstantDataArray::get(Context, Elts);
1065      } else if (EltTy->isIntegerTy(16)) {
1066        SmallVector<uint16_t, 16> Elts(Record.begin(), Record.end());
1067        if (isa<VectorType>(CurTy))
1068          V = ConstantDataVector::get(Context, Elts);
1069        else
1070          V = ConstantDataArray::get(Context, Elts);
1071      } else if (EltTy->isIntegerTy(32)) {
1072        SmallVector<uint32_t, 16> Elts(Record.begin(), Record.end());
1073        if (isa<VectorType>(CurTy))
1074          V = ConstantDataVector::get(Context, Elts);
1075        else
1076          V = ConstantDataArray::get(Context, Elts);
1077      } else if (EltTy->isIntegerTy(64)) {
1078        SmallVector<uint64_t, 16> Elts(Record.begin(), Record.end());
1079        if (isa<VectorType>(CurTy))
1080          V = ConstantDataVector::get(Context, Elts);
1081        else
1082          V = ConstantDataArray::get(Context, Elts);
1083      } else if (EltTy->isFloatTy()) {
1084        SmallVector<float, 16> Elts(Size);
1085        std::transform(Record.begin(), Record.end(), Elts.begin(), BitsToFloat);
1086        if (isa<VectorType>(CurTy))
1087          V = ConstantDataVector::get(Context, Elts);
1088        else
1089          V = ConstantDataArray::get(Context, Elts);
1090      } else if (EltTy->isDoubleTy()) {
1091        SmallVector<double, 16> Elts(Size);
1092        std::transform(Record.begin(), Record.end(), Elts.begin(),
1093                       BitsToDouble);
1094        if (isa<VectorType>(CurTy))
1095          V = ConstantDataVector::get(Context, Elts);
1096        else
1097          V = ConstantDataArray::get(Context, Elts);
1098      } else {
1099        return Error("Unknown element type in CE_DATA");
1100      }
1101      break;
1102    }
1103
1104    case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
1105      if (Record.size() < 3) return Error("Invalid CE_BINOP record");
1106      int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
1107      if (Opc < 0) {
1108        V = UndefValue::get(CurTy);  // Unknown binop.
1109      } else {
1110        Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
1111        Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
1112        unsigned Flags = 0;
1113        if (Record.size() >= 4) {
1114          if (Opc == Instruction::Add ||
1115              Opc == Instruction::Sub ||
1116              Opc == Instruction::Mul ||
1117              Opc == Instruction::Shl) {
1118            if (Record[3] & (1 << bitc::OBO_NO_SIGNED_WRAP))
1119              Flags |= OverflowingBinaryOperator::NoSignedWrap;
1120            if (Record[3] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
1121              Flags |= OverflowingBinaryOperator::NoUnsignedWrap;
1122          } else if (Opc == Instruction::SDiv ||
1123                     Opc == Instruction::UDiv ||
1124                     Opc == Instruction::LShr ||
1125                     Opc == Instruction::AShr) {
1126            if (Record[3] & (1 << bitc::PEO_EXACT))
1127              Flags |= SDivOperator::IsExact;
1128          }
1129        }
1130        V = ConstantExpr::get(Opc, LHS, RHS, Flags);
1131      }
1132      break;
1133    }
1134    case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
1135      if (Record.size() < 3) return Error("Invalid CE_CAST record");
1136      int Opc = GetDecodedCastOpcode(Record[0]);
1137      if (Opc < 0) {
1138        V = UndefValue::get(CurTy);  // Unknown cast.
1139      } else {
1140        Type *OpTy = getTypeByID(Record[1]);
1141        if (!OpTy) return Error("Invalid CE_CAST record");
1142        Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
1143        V = ConstantExpr::getCast(Opc, Op, CurTy);
1144      }
1145      break;
1146    }
1147    case bitc::CST_CODE_CE_INBOUNDS_GEP:
1148    case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
1149      if (Record.size() & 1) return Error("Invalid CE_GEP record");
1150      SmallVector<Constant*, 16> Elts;
1151      for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
1152        Type *ElTy = getTypeByID(Record[i]);
1153        if (!ElTy) return Error("Invalid CE_GEP record");
1154        Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
1155      }
1156      ArrayRef<Constant *> Indices(Elts.begin() + 1, Elts.end());
1157      V = ConstantExpr::getGetElementPtr(Elts[0], Indices,
1158                                         BitCode ==
1159                                           bitc::CST_CODE_CE_INBOUNDS_GEP);
1160      break;
1161    }
1162    case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
1163      if (Record.size() < 3) return Error("Invalid CE_SELECT record");
1164      V = ConstantExpr::getSelect(
1165                          ValueList.getConstantFwdRef(Record[0],
1166                                                      Type::getInt1Ty(Context)),
1167                          ValueList.getConstantFwdRef(Record[1],CurTy),
1168                          ValueList.getConstantFwdRef(Record[2],CurTy));
1169      break;
1170    case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
1171      if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
1172      VectorType *OpTy =
1173        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1174      if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
1175      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1176      Constant *Op1 = ValueList.getConstantFwdRef(Record[2],
1177                                                  Type::getInt32Ty(Context));
1178      V = ConstantExpr::getExtractElement(Op0, Op1);
1179      break;
1180    }
1181    case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
1182      VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1183      if (Record.size() < 3 || OpTy == 0)
1184        return Error("Invalid CE_INSERTELT record");
1185      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1186      Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
1187                                                  OpTy->getElementType());
1188      Constant *Op2 = ValueList.getConstantFwdRef(Record[2],
1189                                                  Type::getInt32Ty(Context));
1190      V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
1191      break;
1192    }
1193    case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
1194      VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1195      if (Record.size() < 3 || OpTy == 0)
1196        return Error("Invalid CE_SHUFFLEVEC record");
1197      Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1198      Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
1199      Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
1200                                                 OpTy->getNumElements());
1201      Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
1202      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1203      break;
1204    }
1205    case bitc::CST_CODE_CE_SHUFVEC_EX: { // [opty, opval, opval, opval]
1206      VectorType *RTy = dyn_cast<VectorType>(CurTy);
1207      VectorType *OpTy =
1208        dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1209      if (Record.size() < 4 || RTy == 0 || OpTy == 0)
1210        return Error("Invalid CE_SHUFVEC_EX record");
1211      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1212      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1213      Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
1214                                                 RTy->getNumElements());
1215      Constant *Op2 = ValueList.getConstantFwdRef(Record[3], ShufTy);
1216      V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1217      break;
1218    }
1219    case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
1220      if (Record.size() < 4) return Error("Invalid CE_CMP record");
1221      Type *OpTy = getTypeByID(Record[0]);
1222      if (OpTy == 0) return Error("Invalid CE_CMP record");
1223      Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1224      Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1225
1226      if (OpTy->isFPOrFPVectorTy())
1227        V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
1228      else
1229        V = ConstantExpr::getICmp(Record[3], Op0, Op1);
1230      break;
1231    }
1232    // This maintains backward compatibility, pre-asm dialect keywords.
1233    // FIXME: Remove with the 4.0 release.
1234    case bitc::CST_CODE_INLINEASM_OLD: {
1235      if (Record.size() < 2) return Error("Invalid INLINEASM record");
1236      std::string AsmStr, ConstrStr;
1237      bool HasSideEffects = Record[0] & 1;
1238      bool IsAlignStack = Record[0] >> 1;
1239      unsigned AsmStrSize = Record[1];
1240      if (2+AsmStrSize >= Record.size())
1241        return Error("Invalid INLINEASM record");
1242      unsigned ConstStrSize = Record[2+AsmStrSize];
1243      if (3+AsmStrSize+ConstStrSize > Record.size())
1244        return Error("Invalid INLINEASM record");
1245
1246      for (unsigned i = 0; i != AsmStrSize; ++i)
1247        AsmStr += (char)Record[2+i];
1248      for (unsigned i = 0; i != ConstStrSize; ++i)
1249        ConstrStr += (char)Record[3+AsmStrSize+i];
1250      PointerType *PTy = cast<PointerType>(CurTy);
1251      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
1252                         AsmStr, ConstrStr, HasSideEffects, IsAlignStack);
1253      break;
1254    }
1255    // This version adds support for the asm dialect keywords (e.g.,
1256    // inteldialect).
1257    case bitc::CST_CODE_INLINEASM: {
1258      if (Record.size() < 2) return Error("Invalid INLINEASM record");
1259      std::string AsmStr, ConstrStr;
1260      bool HasSideEffects = Record[0] & 1;
1261      bool IsAlignStack = (Record[0] >> 1) & 1;
1262      unsigned AsmDialect = Record[0] >> 2;
1263      unsigned AsmStrSize = Record[1];
1264      if (2+AsmStrSize >= Record.size())
1265        return Error("Invalid INLINEASM record");
1266      unsigned ConstStrSize = Record[2+AsmStrSize];
1267      if (3+AsmStrSize+ConstStrSize > Record.size())
1268        return Error("Invalid INLINEASM record");
1269
1270      for (unsigned i = 0; i != AsmStrSize; ++i)
1271        AsmStr += (char)Record[2+i];
1272      for (unsigned i = 0; i != ConstStrSize; ++i)
1273        ConstrStr += (char)Record[3+AsmStrSize+i];
1274      PointerType *PTy = cast<PointerType>(CurTy);
1275      V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
1276                         AsmStr, ConstrStr, HasSideEffects, IsAlignStack,
1277                         InlineAsm::AsmDialect(AsmDialect));
1278      break;
1279    }
1280    case bitc::CST_CODE_BLOCKADDRESS:{
1281      if (Record.size() < 3) return Error("Invalid CE_BLOCKADDRESS record");
1282      Type *FnTy = getTypeByID(Record[0]);
1283      if (FnTy == 0) return Error("Invalid CE_BLOCKADDRESS record");
1284      Function *Fn =
1285        dyn_cast_or_null<Function>(ValueList.getConstantFwdRef(Record[1],FnTy));
1286      if (Fn == 0) return Error("Invalid CE_BLOCKADDRESS record");
1287
1288      // If the function is already parsed we can insert the block address right
1289      // away.
1290      if (!Fn->empty()) {
1291        Function::iterator BBI = Fn->begin(), BBE = Fn->end();
1292        for (size_t I = 0, E = Record[2]; I != E; ++I) {
1293          if (BBI == BBE)
1294            return Error("Invalid blockaddress block #");
1295          ++BBI;
1296        }
1297        V = BlockAddress::get(Fn, BBI);
1298      } else {
1299        // Otherwise insert a placeholder and remember it so it can be inserted
1300        // when the function is parsed.
1301        GlobalVariable *FwdRef = new GlobalVariable(*Fn->getParent(),
1302                                                    Type::getInt8Ty(Context),
1303                                            false, GlobalValue::InternalLinkage,
1304                                                    0, "");
1305        BlockAddrFwdRefs[Fn].push_back(std::make_pair(Record[2], FwdRef));
1306        V = FwdRef;
1307      }
1308      break;
1309    }
1310    }
1311
1312    ValueList.AssignValue(V, NextCstNo);
1313    ++NextCstNo;
1314  }
1315}
1316
1317bool BitcodeReader::ParseUseLists() {
1318  if (Stream.EnterSubBlock(bitc::USELIST_BLOCK_ID))
1319    return Error("Malformed block record");
1320
1321  SmallVector<uint64_t, 64> Record;
1322
1323  // Read all the records.
1324  while (1) {
1325    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
1326
1327    switch (Entry.Kind) {
1328    case BitstreamEntry::SubBlock: // Handled for us already.
1329    case BitstreamEntry::Error:
1330      return Error("malformed use list block");
1331    case BitstreamEntry::EndBlock:
1332      return false;
1333    case BitstreamEntry::Record:
1334      // The interesting case.
1335      break;
1336    }
1337
1338    // Read a use list record.
1339    Record.clear();
1340    switch (Stream.readRecord(Entry.ID, Record)) {
1341    default:  // Default behavior: unknown type.
1342      break;
1343    case bitc::USELIST_CODE_ENTRY: { // USELIST_CODE_ENTRY: TBD.
1344      unsigned RecordLength = Record.size();
1345      if (RecordLength < 1)
1346        return Error ("Invalid UseList reader!");
1347      UseListRecords.push_back(Record);
1348      break;
1349    }
1350    }
1351  }
1352}
1353
1354/// RememberAndSkipFunctionBody - When we see the block for a function body,
1355/// remember where it is and then skip it.  This lets us lazily deserialize the
1356/// functions.
1357bool BitcodeReader::RememberAndSkipFunctionBody() {
1358  // Get the function we are talking about.
1359  if (FunctionsWithBodies.empty())
1360    return Error("Insufficient function protos");
1361
1362  Function *Fn = FunctionsWithBodies.back();
1363  FunctionsWithBodies.pop_back();
1364
1365  // Save the current stream state.
1366  uint64_t CurBit = Stream.GetCurrentBitNo();
1367  DeferredFunctionInfo[Fn] = CurBit;
1368
1369  // Skip over the function block for now.
1370  if (Stream.SkipBlock())
1371    return Error("Malformed block record");
1372  return false;
1373}
1374
1375bool BitcodeReader::GlobalCleanup() {
1376  // Patch the initializers for globals and aliases up.
1377  ResolveGlobalAndAliasInits();
1378  if (!GlobalInits.empty() || !AliasInits.empty())
1379    return Error("Malformed global initializer set");
1380
1381  // Look for intrinsic functions which need to be upgraded at some point
1382  for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
1383       FI != FE; ++FI) {
1384    Function *NewFn;
1385    if (UpgradeIntrinsicFunction(FI, NewFn))
1386      UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
1387  }
1388
1389  // Look for global variables which need to be renamed.
1390  for (Module::global_iterator
1391         GI = TheModule->global_begin(), GE = TheModule->global_end();
1392       GI != GE; ++GI)
1393    UpgradeGlobalVariable(GI);
1394  // Force deallocation of memory for these vectors to favor the client that
1395  // want lazy deserialization.
1396  std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
1397  std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
1398  return false;
1399}
1400
1401bool BitcodeReader::ParseModule(bool Resume) {
1402  if (Resume)
1403    Stream.JumpToBit(NextUnreadBit);
1404  else if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
1405    return Error("Malformed block record");
1406
1407  SmallVector<uint64_t, 64> Record;
1408  std::vector<std::string> SectionTable;
1409  std::vector<std::string> GCTable;
1410
1411  // Read all the records for this module.
1412  while (1) {
1413    BitstreamEntry Entry = Stream.advance();
1414
1415    switch (Entry.Kind) {
1416    case BitstreamEntry::Error:
1417      Error("malformed module block");
1418      return true;
1419    case BitstreamEntry::EndBlock:
1420      return GlobalCleanup();
1421
1422    case BitstreamEntry::SubBlock:
1423      switch (Entry.ID) {
1424      default:  // Skip unknown content.
1425        if (Stream.SkipBlock())
1426          return Error("Malformed block record");
1427        break;
1428      case bitc::BLOCKINFO_BLOCK_ID:
1429        if (Stream.ReadBlockInfoBlock())
1430          return Error("Malformed BlockInfoBlock");
1431        break;
1432      case bitc::PARAMATTR_BLOCK_ID:
1433        if (ParseAttributeBlock())
1434          return true;
1435        break;
1436      case bitc::TYPE_BLOCK_ID_NEW:
1437        if (ParseTypeTable())
1438          return true;
1439        break;
1440      case bitc::VALUE_SYMTAB_BLOCK_ID:
1441        if (ParseValueSymbolTable())
1442          return true;
1443        SeenValueSymbolTable = true;
1444        break;
1445      case bitc::CONSTANTS_BLOCK_ID:
1446        if (ParseConstants() || ResolveGlobalAndAliasInits())
1447          return true;
1448        break;
1449      case bitc::METADATA_BLOCK_ID:
1450        if (ParseMetadata())
1451          return true;
1452        break;
1453      case bitc::FUNCTION_BLOCK_ID:
1454        // If this is the first function body we've seen, reverse the
1455        // FunctionsWithBodies list.
1456        if (!SeenFirstFunctionBody) {
1457          std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
1458          if (GlobalCleanup())
1459            return true;
1460          SeenFirstFunctionBody = true;
1461        }
1462
1463        if (RememberAndSkipFunctionBody())
1464          return true;
1465        // For streaming bitcode, suspend parsing when we reach the function
1466        // bodies. Subsequent materialization calls will resume it when
1467        // necessary. For streaming, the function bodies must be at the end of
1468        // the bitcode. If the bitcode file is old, the symbol table will be
1469        // at the end instead and will not have been seen yet. In this case,
1470        // just finish the parse now.
1471        if (LazyStreamer && SeenValueSymbolTable) {
1472          NextUnreadBit = Stream.GetCurrentBitNo();
1473          return false;
1474        }
1475        break;
1476      case bitc::USELIST_BLOCK_ID:
1477        if (ParseUseLists())
1478          return true;
1479        break;
1480      }
1481      continue;
1482
1483    case BitstreamEntry::Record:
1484      // The interesting case.
1485      break;
1486    }
1487
1488
1489    // Read a record.
1490    switch (Stream.readRecord(Entry.ID, Record)) {
1491    default: break;  // Default behavior, ignore unknown content.
1492    case bitc::MODULE_CODE_VERSION: {  // VERSION: [version#]
1493      if (Record.size() < 1)
1494        return Error("Malformed MODULE_CODE_VERSION");
1495      // Only version #0 and #1 are supported so far.
1496      unsigned module_version = Record[0];
1497      switch (module_version) {
1498        default: return Error("Unknown bitstream version!");
1499        case 0:
1500          UseRelativeIDs = false;
1501          break;
1502        case 1:
1503          UseRelativeIDs = true;
1504          break;
1505      }
1506      break;
1507    }
1508    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1509      std::string S;
1510      if (ConvertToString(Record, 0, S))
1511        return Error("Invalid MODULE_CODE_TRIPLE record");
1512      TheModule->setTargetTriple(S);
1513      break;
1514    }
1515    case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
1516      std::string S;
1517      if (ConvertToString(Record, 0, S))
1518        return Error("Invalid MODULE_CODE_DATALAYOUT record");
1519      TheModule->setDataLayout(S);
1520      break;
1521    }
1522    case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
1523      std::string S;
1524      if (ConvertToString(Record, 0, S))
1525        return Error("Invalid MODULE_CODE_ASM record");
1526      TheModule->setModuleInlineAsm(S);
1527      break;
1528    }
1529    case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
1530      // FIXME: Remove in 4.0.
1531      std::string S;
1532      if (ConvertToString(Record, 0, S))
1533        return Error("Invalid MODULE_CODE_DEPLIB record");
1534      // Ignore value.
1535      break;
1536    }
1537    case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
1538      std::string S;
1539      if (ConvertToString(Record, 0, S))
1540        return Error("Invalid MODULE_CODE_SECTIONNAME record");
1541      SectionTable.push_back(S);
1542      break;
1543    }
1544    case bitc::MODULE_CODE_GCNAME: {  // SECTIONNAME: [strchr x N]
1545      std::string S;
1546      if (ConvertToString(Record, 0, S))
1547        return Error("Invalid MODULE_CODE_GCNAME record");
1548      GCTable.push_back(S);
1549      break;
1550    }
1551    // GLOBALVAR: [pointer type, isconst, initid,
1552    //             linkage, alignment, section, visibility, threadlocal,
1553    //             unnamed_addr]
1554    case bitc::MODULE_CODE_GLOBALVAR: {
1555      if (Record.size() < 6)
1556        return Error("Invalid MODULE_CODE_GLOBALVAR record");
1557      Type *Ty = getTypeByID(Record[0]);
1558      if (!Ty) return Error("Invalid MODULE_CODE_GLOBALVAR record");
1559      if (!Ty->isPointerTy())
1560        return Error("Global not a pointer type!");
1561      unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
1562      Ty = cast<PointerType>(Ty)->getElementType();
1563
1564      bool isConstant = Record[1];
1565      GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1566      unsigned Alignment = (1 << Record[4]) >> 1;
1567      std::string Section;
1568      if (Record[5]) {
1569        if (Record[5]-1 >= SectionTable.size())
1570          return Error("Invalid section ID");
1571        Section = SectionTable[Record[5]-1];
1572      }
1573      GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1574      if (Record.size() > 6)
1575        Visibility = GetDecodedVisibility(Record[6]);
1576
1577      GlobalVariable::ThreadLocalMode TLM = GlobalVariable::NotThreadLocal;
1578      if (Record.size() > 7)
1579        TLM = GetDecodedThreadLocalMode(Record[7]);
1580
1581      bool UnnamedAddr = false;
1582      if (Record.size() > 8)
1583        UnnamedAddr = Record[8];
1584
1585      GlobalVariable *NewGV =
1586        new GlobalVariable(*TheModule, Ty, isConstant, Linkage, 0, "", 0,
1587                           TLM, AddressSpace);
1588      NewGV->setAlignment(Alignment);
1589      if (!Section.empty())
1590        NewGV->setSection(Section);
1591      NewGV->setVisibility(Visibility);
1592      NewGV->setUnnamedAddr(UnnamedAddr);
1593
1594      ValueList.push_back(NewGV);
1595
1596      // Remember which value to use for the global initializer.
1597      if (unsigned InitID = Record[2])
1598        GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1599      break;
1600    }
1601    // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1602    //             alignment, section, visibility, gc, unnamed_addr]
1603    case bitc::MODULE_CODE_FUNCTION: {
1604      if (Record.size() < 8)
1605        return Error("Invalid MODULE_CODE_FUNCTION record");
1606      Type *Ty = getTypeByID(Record[0]);
1607      if (!Ty) return Error("Invalid MODULE_CODE_FUNCTION record");
1608      if (!Ty->isPointerTy())
1609        return Error("Function not a pointer type!");
1610      FunctionType *FTy =
1611        dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1612      if (!FTy)
1613        return Error("Function not a pointer to function type!");
1614
1615      Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
1616                                        "", TheModule);
1617
1618      Func->setCallingConv(static_cast<CallingConv::ID>(Record[1]));
1619      bool isProto = Record[2];
1620      Func->setLinkage(GetDecodedLinkage(Record[3]));
1621      Func->setAttributes(getAttributes(Record[4]));
1622
1623      Func->setAlignment((1 << Record[5]) >> 1);
1624      if (Record[6]) {
1625        if (Record[6]-1 >= SectionTable.size())
1626          return Error("Invalid section ID");
1627        Func->setSection(SectionTable[Record[6]-1]);
1628      }
1629      Func->setVisibility(GetDecodedVisibility(Record[7]));
1630      if (Record.size() > 8 && Record[8]) {
1631        if (Record[8]-1 > GCTable.size())
1632          return Error("Invalid GC ID");
1633        Func->setGC(GCTable[Record[8]-1].c_str());
1634      }
1635      bool UnnamedAddr = false;
1636      if (Record.size() > 9)
1637        UnnamedAddr = Record[9];
1638      Func->setUnnamedAddr(UnnamedAddr);
1639      ValueList.push_back(Func);
1640
1641      // If this is a function with a body, remember the prototype we are
1642      // creating now, so that we can match up the body with them later.
1643      if (!isProto) {
1644        FunctionsWithBodies.push_back(Func);
1645        if (LazyStreamer) DeferredFunctionInfo[Func] = 0;
1646      }
1647      break;
1648    }
1649    // ALIAS: [alias type, aliasee val#, linkage]
1650    // ALIAS: [alias type, aliasee val#, linkage, visibility]
1651    case bitc::MODULE_CODE_ALIAS: {
1652      if (Record.size() < 3)
1653        return Error("Invalid MODULE_ALIAS record");
1654      Type *Ty = getTypeByID(Record[0]);
1655      if (!Ty) return Error("Invalid MODULE_ALIAS record");
1656      if (!Ty->isPointerTy())
1657        return Error("Function not a pointer type!");
1658
1659      GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1660                                           "", 0, TheModule);
1661      // Old bitcode files didn't have visibility field.
1662      if (Record.size() > 3)
1663        NewGA->setVisibility(GetDecodedVisibility(Record[3]));
1664      ValueList.push_back(NewGA);
1665      AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1666      break;
1667    }
1668    /// MODULE_CODE_PURGEVALS: [numvals]
1669    case bitc::MODULE_CODE_PURGEVALS:
1670      // Trim down the value list to the specified size.
1671      if (Record.size() < 1 || Record[0] > ValueList.size())
1672        return Error("Invalid MODULE_PURGEVALS record");
1673      ValueList.shrinkTo(Record[0]);
1674      break;
1675    }
1676    Record.clear();
1677  }
1678}
1679
1680bool BitcodeReader::ParseBitcodeInto(Module *M) {
1681  TheModule = 0;
1682
1683  if (InitStream()) return true;
1684
1685  // Sniff for the signature.
1686  if (Stream.Read(8) != 'B' ||
1687      Stream.Read(8) != 'C' ||
1688      Stream.Read(4) != 0x0 ||
1689      Stream.Read(4) != 0xC ||
1690      Stream.Read(4) != 0xE ||
1691      Stream.Read(4) != 0xD)
1692    return Error("Invalid bitcode signature");
1693
1694  // We expect a number of well-defined blocks, though we don't necessarily
1695  // need to understand them all.
1696  while (1) {
1697    if (Stream.AtEndOfStream())
1698      return false;
1699
1700    BitstreamEntry Entry =
1701      Stream.advance(BitstreamCursor::AF_DontAutoprocessAbbrevs);
1702
1703    switch (Entry.Kind) {
1704    case BitstreamEntry::Error:
1705      Error("malformed module file");
1706      return true;
1707    case BitstreamEntry::EndBlock:
1708      return false;
1709
1710    case BitstreamEntry::SubBlock:
1711      switch (Entry.ID) {
1712      case bitc::BLOCKINFO_BLOCK_ID:
1713        if (Stream.ReadBlockInfoBlock())
1714          return Error("Malformed BlockInfoBlock");
1715        break;
1716      case bitc::MODULE_BLOCK_ID:
1717        // Reject multiple MODULE_BLOCK's in a single bitstream.
1718        if (TheModule)
1719          return Error("Multiple MODULE_BLOCKs in same stream");
1720        TheModule = M;
1721        if (ParseModule(false))
1722          return true;
1723        if (LazyStreamer) return false;
1724        break;
1725      default:
1726        if (Stream.SkipBlock())
1727          return Error("Malformed block record");
1728        break;
1729      }
1730      continue;
1731    case BitstreamEntry::Record:
1732      // There should be no records in the top-level of blocks.
1733
1734      // The ranlib in Xcode 4 will align archive members by appending newlines
1735      // to the end of them. If this file size is a multiple of 4 but not 8, we
1736      // have to read and ignore these final 4 bytes :-(
1737      if (Stream.getAbbrevIDWidth() == 2 && Entry.ID == 2 &&
1738          Stream.Read(6) == 2 && Stream.Read(24) == 0xa0a0a &&
1739          Stream.AtEndOfStream())
1740        return false;
1741
1742      return Error("Invalid record at top-level");
1743    }
1744  }
1745}
1746
1747bool BitcodeReader::ParseModuleTriple(std::string &Triple) {
1748  if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
1749    return Error("Malformed block record");
1750
1751  SmallVector<uint64_t, 64> Record;
1752
1753  // Read all the records for this module.
1754  while (1) {
1755    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
1756
1757    switch (Entry.Kind) {
1758    case BitstreamEntry::SubBlock: // Handled for us already.
1759    case BitstreamEntry::Error:
1760      return Error("malformed module block");
1761    case BitstreamEntry::EndBlock:
1762      return false;
1763    case BitstreamEntry::Record:
1764      // The interesting case.
1765      break;
1766    }
1767
1768    // Read a record.
1769    switch (Stream.readRecord(Entry.ID, Record)) {
1770    default: break;  // Default behavior, ignore unknown content.
1771    case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1772      std::string S;
1773      if (ConvertToString(Record, 0, S))
1774        return Error("Invalid MODULE_CODE_TRIPLE record");
1775      Triple = S;
1776      break;
1777    }
1778    }
1779    Record.clear();
1780  }
1781}
1782
1783bool BitcodeReader::ParseTriple(std::string &Triple) {
1784  if (InitStream()) return true;
1785
1786  // Sniff for the signature.
1787  if (Stream.Read(8) != 'B' ||
1788      Stream.Read(8) != 'C' ||
1789      Stream.Read(4) != 0x0 ||
1790      Stream.Read(4) != 0xC ||
1791      Stream.Read(4) != 0xE ||
1792      Stream.Read(4) != 0xD)
1793    return Error("Invalid bitcode signature");
1794
1795  // We expect a number of well-defined blocks, though we don't necessarily
1796  // need to understand them all.
1797  while (1) {
1798    BitstreamEntry Entry = Stream.advance();
1799
1800    switch (Entry.Kind) {
1801    case BitstreamEntry::Error:
1802      Error("malformed module file");
1803      return true;
1804    case BitstreamEntry::EndBlock:
1805      return false;
1806
1807    case BitstreamEntry::SubBlock:
1808      if (Entry.ID == bitc::MODULE_BLOCK_ID)
1809        return ParseModuleTriple(Triple);
1810
1811      // Ignore other sub-blocks.
1812      if (Stream.SkipBlock()) {
1813        Error("malformed block record in AST file");
1814        return true;
1815      }
1816      continue;
1817
1818    case BitstreamEntry::Record:
1819      Stream.skipRecord(Entry.ID);
1820      continue;
1821    }
1822  }
1823}
1824
1825/// ParseMetadataAttachment - Parse metadata attachments.
1826bool BitcodeReader::ParseMetadataAttachment() {
1827  if (Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
1828    return Error("Malformed block record");
1829
1830  SmallVector<uint64_t, 64> Record;
1831  while (1) {
1832    BitstreamEntry Entry = Stream.advanceSkippingSubblocks();
1833
1834    switch (Entry.Kind) {
1835    case BitstreamEntry::SubBlock: // Handled for us already.
1836    case BitstreamEntry::Error:
1837      return Error("malformed metadata block");
1838    case BitstreamEntry::EndBlock:
1839      return false;
1840    case BitstreamEntry::Record:
1841      // The interesting case.
1842      break;
1843    }
1844
1845    // Read a metadata attachment record.
1846    Record.clear();
1847    switch (Stream.readRecord(Entry.ID, Record)) {
1848    default:  // Default behavior: ignore.
1849      break;
1850    case bitc::METADATA_ATTACHMENT: {
1851      unsigned RecordLength = Record.size();
1852      if (Record.empty() || (RecordLength - 1) % 2 == 1)
1853        return Error ("Invalid METADATA_ATTACHMENT reader!");
1854      Instruction *Inst = InstructionList[Record[0]];
1855      for (unsigned i = 1; i != RecordLength; i = i+2) {
1856        unsigned Kind = Record[i];
1857        DenseMap<unsigned, unsigned>::iterator I =
1858          MDKindMap.find(Kind);
1859        if (I == MDKindMap.end())
1860          return Error("Invalid metadata kind ID");
1861        Value *Node = MDValueList.getValueFwdRef(Record[i+1]);
1862        Inst->setMetadata(I->second, cast<MDNode>(Node));
1863      }
1864      break;
1865    }
1866    }
1867  }
1868}
1869
1870/// ParseFunctionBody - Lazily parse the specified function body block.
1871bool BitcodeReader::ParseFunctionBody(Function *F) {
1872  if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1873    return Error("Malformed block record");
1874
1875  InstructionList.clear();
1876  unsigned ModuleValueListSize = ValueList.size();
1877  unsigned ModuleMDValueListSize = MDValueList.size();
1878
1879  // Add all the function arguments to the value table.
1880  for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1881    ValueList.push_back(I);
1882
1883  unsigned NextValueNo = ValueList.size();
1884  BasicBlock *CurBB = 0;
1885  unsigned CurBBNo = 0;
1886
1887  DebugLoc LastLoc;
1888
1889  // Read all the records.
1890  SmallVector<uint64_t, 64> Record;
1891  while (1) {
1892    BitstreamEntry Entry = Stream.advance();
1893
1894    switch (Entry.Kind) {
1895    case BitstreamEntry::Error:
1896      return Error("Bitcode error in function block");
1897    case BitstreamEntry::EndBlock:
1898      goto OutOfRecordLoop;
1899
1900    case BitstreamEntry::SubBlock:
1901      switch (Entry.ID) {
1902      default:  // Skip unknown content.
1903        if (Stream.SkipBlock())
1904          return Error("Malformed block record");
1905        break;
1906      case bitc::CONSTANTS_BLOCK_ID:
1907        if (ParseConstants()) return true;
1908        NextValueNo = ValueList.size();
1909        break;
1910      case bitc::VALUE_SYMTAB_BLOCK_ID:
1911        if (ParseValueSymbolTable()) return true;
1912        break;
1913      case bitc::METADATA_ATTACHMENT_ID:
1914        if (ParseMetadataAttachment()) return true;
1915        break;
1916      case bitc::METADATA_BLOCK_ID:
1917        if (ParseMetadata()) return true;
1918        break;
1919      }
1920      continue;
1921
1922    case BitstreamEntry::Record:
1923      // The interesting case.
1924      break;
1925    }
1926
1927    // Read a record.
1928    Record.clear();
1929    Instruction *I = 0;
1930    unsigned BitCode = Stream.readRecord(Entry.ID, Record);
1931    switch (BitCode) {
1932    default: // Default behavior: reject
1933      return Error("Unknown instruction");
1934    case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1935      if (Record.size() < 1 || Record[0] == 0)
1936        return Error("Invalid DECLAREBLOCKS record");
1937      // Create all the basic blocks for the function.
1938      FunctionBBs.resize(Record[0]);
1939      for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1940        FunctionBBs[i] = BasicBlock::Create(Context, "", F);
1941      CurBB = FunctionBBs[0];
1942      continue;
1943
1944    case bitc::FUNC_CODE_DEBUG_LOC_AGAIN:  // DEBUG_LOC_AGAIN
1945      // This record indicates that the last instruction is at the same
1946      // location as the previous instruction with a location.
1947      I = 0;
1948
1949      // Get the last instruction emitted.
1950      if (CurBB && !CurBB->empty())
1951        I = &CurBB->back();
1952      else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
1953               !FunctionBBs[CurBBNo-1]->empty())
1954        I = &FunctionBBs[CurBBNo-1]->back();
1955
1956      if (I == 0) return Error("Invalid DEBUG_LOC_AGAIN record");
1957      I->setDebugLoc(LastLoc);
1958      I = 0;
1959      continue;
1960
1961    case bitc::FUNC_CODE_DEBUG_LOC: {      // DEBUG_LOC: [line, col, scope, ia]
1962      I = 0;     // Get the last instruction emitted.
1963      if (CurBB && !CurBB->empty())
1964        I = &CurBB->back();
1965      else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
1966               !FunctionBBs[CurBBNo-1]->empty())
1967        I = &FunctionBBs[CurBBNo-1]->back();
1968      if (I == 0 || Record.size() < 4)
1969        return Error("Invalid FUNC_CODE_DEBUG_LOC record");
1970
1971      unsigned Line = Record[0], Col = Record[1];
1972      unsigned ScopeID = Record[2], IAID = Record[3];
1973
1974      MDNode *Scope = 0, *IA = 0;
1975      if (ScopeID) Scope = cast<MDNode>(MDValueList.getValueFwdRef(ScopeID-1));
1976      if (IAID)    IA = cast<MDNode>(MDValueList.getValueFwdRef(IAID-1));
1977      LastLoc = DebugLoc::get(Line, Col, Scope, IA);
1978      I->setDebugLoc(LastLoc);
1979      I = 0;
1980      continue;
1981    }
1982
1983    case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1984      unsigned OpNum = 0;
1985      Value *LHS, *RHS;
1986      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1987          popValue(Record, OpNum, NextValueNo, LHS->getType(), RHS) ||
1988          OpNum+1 > Record.size())
1989        return Error("Invalid BINOP record");
1990
1991      int Opc = GetDecodedBinaryOpcode(Record[OpNum++], LHS->getType());
1992      if (Opc == -1) return Error("Invalid BINOP record");
1993      I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
1994      InstructionList.push_back(I);
1995      if (OpNum < Record.size()) {
1996        if (Opc == Instruction::Add ||
1997            Opc == Instruction::Sub ||
1998            Opc == Instruction::Mul ||
1999            Opc == Instruction::Shl) {
2000          if (Record[OpNum] & (1 << bitc::OBO_NO_SIGNED_WRAP))
2001            cast<BinaryOperator>(I)->setHasNoSignedWrap(true);
2002          if (Record[OpNum] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
2003            cast<BinaryOperator>(I)->setHasNoUnsignedWrap(true);
2004        } else if (Opc == Instruction::SDiv ||
2005                   Opc == Instruction::UDiv ||
2006                   Opc == Instruction::LShr ||
2007                   Opc == Instruction::AShr) {
2008          if (Record[OpNum] & (1 << bitc::PEO_EXACT))
2009            cast<BinaryOperator>(I)->setIsExact(true);
2010        } else if (isa<FPMathOperator>(I)) {
2011          FastMathFlags FMF;
2012          if (0 != (Record[OpNum] & FastMathFlags::UnsafeAlgebra))
2013            FMF.setUnsafeAlgebra();
2014          if (0 != (Record[OpNum] & FastMathFlags::NoNaNs))
2015            FMF.setNoNaNs();
2016          if (0 != (Record[OpNum] & FastMathFlags::NoInfs))
2017            FMF.setNoInfs();
2018          if (0 != (Record[OpNum] & FastMathFlags::NoSignedZeros))
2019            FMF.setNoSignedZeros();
2020          if (0 != (Record[OpNum] & FastMathFlags::AllowReciprocal))
2021            FMF.setAllowReciprocal();
2022          if (FMF.any())
2023            I->setFastMathFlags(FMF);
2024        }
2025
2026      }
2027      break;
2028    }
2029    case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
2030      unsigned OpNum = 0;
2031      Value *Op;
2032      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2033          OpNum+2 != Record.size())
2034        return Error("Invalid CAST record");
2035
2036      Type *ResTy = getTypeByID(Record[OpNum]);
2037      int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
2038      if (Opc == -1 || ResTy == 0)
2039        return Error("Invalid CAST record");
2040      I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
2041      InstructionList.push_back(I);
2042      break;
2043    }
2044    case bitc::FUNC_CODE_INST_INBOUNDS_GEP:
2045    case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
2046      unsigned OpNum = 0;
2047      Value *BasePtr;
2048      if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
2049        return Error("Invalid GEP record");
2050
2051      SmallVector<Value*, 16> GEPIdx;
2052      while (OpNum != Record.size()) {
2053        Value *Op;
2054        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2055          return Error("Invalid GEP record");
2056        GEPIdx.push_back(Op);
2057      }
2058
2059      I = GetElementPtrInst::Create(BasePtr, GEPIdx);
2060      InstructionList.push_back(I);
2061      if (BitCode == bitc::FUNC_CODE_INST_INBOUNDS_GEP)
2062        cast<GetElementPtrInst>(I)->setIsInBounds(true);
2063      break;
2064    }
2065
2066    case bitc::FUNC_CODE_INST_EXTRACTVAL: {
2067                                       // EXTRACTVAL: [opty, opval, n x indices]
2068      unsigned OpNum = 0;
2069      Value *Agg;
2070      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2071        return Error("Invalid EXTRACTVAL record");
2072
2073      SmallVector<unsigned, 4> EXTRACTVALIdx;
2074      for (unsigned RecSize = Record.size();
2075           OpNum != RecSize; ++OpNum) {
2076        uint64_t Index = Record[OpNum];
2077        if ((unsigned)Index != Index)
2078          return Error("Invalid EXTRACTVAL index");
2079        EXTRACTVALIdx.push_back((unsigned)Index);
2080      }
2081
2082      I = ExtractValueInst::Create(Agg, EXTRACTVALIdx);
2083      InstructionList.push_back(I);
2084      break;
2085    }
2086
2087    case bitc::FUNC_CODE_INST_INSERTVAL: {
2088                           // INSERTVAL: [opty, opval, opty, opval, n x indices]
2089      unsigned OpNum = 0;
2090      Value *Agg;
2091      if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2092        return Error("Invalid INSERTVAL record");
2093      Value *Val;
2094      if (getValueTypePair(Record, OpNum, NextValueNo, Val))
2095        return Error("Invalid INSERTVAL record");
2096
2097      SmallVector<unsigned, 4> INSERTVALIdx;
2098      for (unsigned RecSize = Record.size();
2099           OpNum != RecSize; ++OpNum) {
2100        uint64_t Index = Record[OpNum];
2101        if ((unsigned)Index != Index)
2102          return Error("Invalid INSERTVAL index");
2103        INSERTVALIdx.push_back((unsigned)Index);
2104      }
2105
2106      I = InsertValueInst::Create(Agg, Val, INSERTVALIdx);
2107      InstructionList.push_back(I);
2108      break;
2109    }
2110
2111    case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
2112      // obsolete form of select
2113      // handles select i1 ... in old bitcode
2114      unsigned OpNum = 0;
2115      Value *TrueVal, *FalseVal, *Cond;
2116      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2117          popValue(Record, OpNum, NextValueNo, TrueVal->getType(), FalseVal) ||
2118          popValue(Record, OpNum, NextValueNo, Type::getInt1Ty(Context), Cond))
2119        return Error("Invalid SELECT record");
2120
2121      I = SelectInst::Create(Cond, TrueVal, FalseVal);
2122      InstructionList.push_back(I);
2123      break;
2124    }
2125
2126    case bitc::FUNC_CODE_INST_VSELECT: {// VSELECT: [ty,opval,opval,predty,pred]
2127      // new form of select
2128      // handles select i1 or select [N x i1]
2129      unsigned OpNum = 0;
2130      Value *TrueVal, *FalseVal, *Cond;
2131      if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2132          popValue(Record, OpNum, NextValueNo, TrueVal->getType(), FalseVal) ||
2133          getValueTypePair(Record, OpNum, NextValueNo, Cond))
2134        return Error("Invalid SELECT record");
2135
2136      // select condition can be either i1 or [N x i1]
2137      if (VectorType* vector_type =
2138          dyn_cast<VectorType>(Cond->getType())) {
2139        // expect <n x i1>
2140        if (vector_type->getElementType() != Type::getInt1Ty(Context))
2141          return Error("Invalid SELECT condition type");
2142      } else {
2143        // expect i1
2144        if (Cond->getType() != Type::getInt1Ty(Context))
2145          return Error("Invalid SELECT condition type");
2146      }
2147
2148      I = SelectInst::Create(Cond, TrueVal, FalseVal);
2149      InstructionList.push_back(I);
2150      break;
2151    }
2152
2153    case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
2154      unsigned OpNum = 0;
2155      Value *Vec, *Idx;
2156      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2157          popValue(Record, OpNum, NextValueNo, Type::getInt32Ty(Context), Idx))
2158        return Error("Invalid EXTRACTELT record");
2159      I = ExtractElementInst::Create(Vec, Idx);
2160      InstructionList.push_back(I);
2161      break;
2162    }
2163
2164    case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
2165      unsigned OpNum = 0;
2166      Value *Vec, *Elt, *Idx;
2167      if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2168          popValue(Record, OpNum, NextValueNo,
2169                   cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
2170          popValue(Record, OpNum, NextValueNo, Type::getInt32Ty(Context), Idx))
2171        return Error("Invalid INSERTELT record");
2172      I = InsertElementInst::Create(Vec, Elt, Idx);
2173      InstructionList.push_back(I);
2174      break;
2175    }
2176
2177    case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
2178      unsigned OpNum = 0;
2179      Value *Vec1, *Vec2, *Mask;
2180      if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
2181          popValue(Record, OpNum, NextValueNo, Vec1->getType(), Vec2))
2182        return Error("Invalid SHUFFLEVEC record");
2183
2184      if (getValueTypePair(Record, OpNum, NextValueNo, Mask))
2185        return Error("Invalid SHUFFLEVEC record");
2186      I = new ShuffleVectorInst(Vec1, Vec2, Mask);
2187      InstructionList.push_back(I);
2188      break;
2189    }
2190
2191    case bitc::FUNC_CODE_INST_CMP:   // CMP: [opty, opval, opval, pred]
2192      // Old form of ICmp/FCmp returning bool
2193      // Existed to differentiate between icmp/fcmp and vicmp/vfcmp which were
2194      // both legal on vectors but had different behaviour.
2195    case bitc::FUNC_CODE_INST_CMP2: { // CMP2: [opty, opval, opval, pred]
2196      // FCmp/ICmp returning bool or vector of bool
2197
2198      unsigned OpNum = 0;
2199      Value *LHS, *RHS;
2200      if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
2201          popValue(Record, OpNum, NextValueNo, LHS->getType(), RHS) ||
2202          OpNum+1 != Record.size())
2203        return Error("Invalid CMP record");
2204
2205      if (LHS->getType()->isFPOrFPVectorTy())
2206        I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
2207      else
2208        I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
2209      InstructionList.push_back(I);
2210      break;
2211    }
2212
2213    case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
2214      {
2215        unsigned Size = Record.size();
2216        if (Size == 0) {
2217          I = ReturnInst::Create(Context);
2218          InstructionList.push_back(I);
2219          break;
2220        }
2221
2222        unsigned OpNum = 0;
2223        Value *Op = NULL;
2224        if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2225          return Error("Invalid RET record");
2226        if (OpNum != Record.size())
2227          return Error("Invalid RET record");
2228
2229        I = ReturnInst::Create(Context, Op);
2230        InstructionList.push_back(I);
2231        break;
2232      }
2233    case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
2234      if (Record.size() != 1 && Record.size() != 3)
2235        return Error("Invalid BR record");
2236      BasicBlock *TrueDest = getBasicBlock(Record[0]);
2237      if (TrueDest == 0)
2238        return Error("Invalid BR record");
2239
2240      if (Record.size() == 1) {
2241        I = BranchInst::Create(TrueDest);
2242        InstructionList.push_back(I);
2243      }
2244      else {
2245        BasicBlock *FalseDest = getBasicBlock(Record[1]);
2246        Value *Cond = getValue(Record, 2, NextValueNo,
2247                               Type::getInt1Ty(Context));
2248        if (FalseDest == 0 || Cond == 0)
2249          return Error("Invalid BR record");
2250        I = BranchInst::Create(TrueDest, FalseDest, Cond);
2251        InstructionList.push_back(I);
2252      }
2253      break;
2254    }
2255    case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, op0, op1, ...]
2256      // Check magic
2257      if ((Record[0] >> 16) == SWITCH_INST_MAGIC) {
2258        // New SwitchInst format with case ranges.
2259
2260        Type *OpTy = getTypeByID(Record[1]);
2261        unsigned ValueBitWidth = cast<IntegerType>(OpTy)->getBitWidth();
2262
2263        Value *Cond = getValue(Record, 2, NextValueNo, OpTy);
2264        BasicBlock *Default = getBasicBlock(Record[3]);
2265        if (OpTy == 0 || Cond == 0 || Default == 0)
2266          return Error("Invalid SWITCH record");
2267
2268        unsigned NumCases = Record[4];
2269
2270        SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
2271        InstructionList.push_back(SI);
2272
2273        unsigned CurIdx = 5;
2274        for (unsigned i = 0; i != NumCases; ++i) {
2275          IntegersSubsetToBB CaseBuilder;
2276          unsigned NumItems = Record[CurIdx++];
2277          for (unsigned ci = 0; ci != NumItems; ++ci) {
2278            bool isSingleNumber = Record[CurIdx++];
2279
2280            APInt Low;
2281            unsigned ActiveWords = 1;
2282            if (ValueBitWidth > 64)
2283              ActiveWords = Record[CurIdx++];
2284            Low = ReadWideAPInt(makeArrayRef(&Record[CurIdx], ActiveWords),
2285                                ValueBitWidth);
2286            CurIdx += ActiveWords;
2287
2288            if (!isSingleNumber) {
2289              ActiveWords = 1;
2290              if (ValueBitWidth > 64)
2291                ActiveWords = Record[CurIdx++];
2292              APInt High =
2293                  ReadWideAPInt(makeArrayRef(&Record[CurIdx], ActiveWords),
2294                                ValueBitWidth);
2295
2296              CaseBuilder.add(IntItem::fromType(OpTy, Low),
2297                              IntItem::fromType(OpTy, High));
2298              CurIdx += ActiveWords;
2299            } else
2300              CaseBuilder.add(IntItem::fromType(OpTy, Low));
2301          }
2302          BasicBlock *DestBB = getBasicBlock(Record[CurIdx++]);
2303          IntegersSubset Case = CaseBuilder.getCase();
2304          SI->addCase(Case, DestBB);
2305        }
2306        uint16_t Hash = SI->hash();
2307        if (Hash != (Record[0] & 0xFFFF))
2308          return Error("Invalid SWITCH record");
2309        I = SI;
2310        break;
2311      }
2312
2313      // Old SwitchInst format without case ranges.
2314
2315      if (Record.size() < 3 || (Record.size() & 1) == 0)
2316        return Error("Invalid SWITCH record");
2317      Type *OpTy = getTypeByID(Record[0]);
2318      Value *Cond = getValue(Record, 1, NextValueNo, OpTy);
2319      BasicBlock *Default = getBasicBlock(Record[2]);
2320      if (OpTy == 0 || Cond == 0 || Default == 0)
2321        return Error("Invalid SWITCH record");
2322      unsigned NumCases = (Record.size()-3)/2;
2323      SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
2324      InstructionList.push_back(SI);
2325      for (unsigned i = 0, e = NumCases; i != e; ++i) {
2326        ConstantInt *CaseVal =
2327          dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
2328        BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
2329        if (CaseVal == 0 || DestBB == 0) {
2330          delete SI;
2331          return Error("Invalid SWITCH record!");
2332        }
2333        SI->addCase(CaseVal, DestBB);
2334      }
2335      I = SI;
2336      break;
2337    }
2338    case bitc::FUNC_CODE_INST_INDIRECTBR: { // INDIRECTBR: [opty, op0, op1, ...]
2339      if (Record.size() < 2)
2340        return Error("Invalid INDIRECTBR record");
2341      Type *OpTy = getTypeByID(Record[0]);
2342      Value *Address = getValue(Record, 1, NextValueNo, OpTy);
2343      if (OpTy == 0 || Address == 0)
2344        return Error("Invalid INDIRECTBR record");
2345      unsigned NumDests = Record.size()-2;
2346      IndirectBrInst *IBI = IndirectBrInst::Create(Address, NumDests);
2347      InstructionList.push_back(IBI);
2348      for (unsigned i = 0, e = NumDests; i != e; ++i) {
2349        if (BasicBlock *DestBB = getBasicBlock(Record[2+i])) {
2350          IBI->addDestination(DestBB);
2351        } else {
2352          delete IBI;
2353          return Error("Invalid INDIRECTBR record!");
2354        }
2355      }
2356      I = IBI;
2357      break;
2358    }
2359
2360    case bitc::FUNC_CODE_INST_INVOKE: {
2361      // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
2362      if (Record.size() < 4) return Error("Invalid INVOKE record");
2363      AttributeSet PAL = getAttributes(Record[0]);
2364      unsigned CCInfo = Record[1];
2365      BasicBlock *NormalBB = getBasicBlock(Record[2]);
2366      BasicBlock *UnwindBB = getBasicBlock(Record[3]);
2367
2368      unsigned OpNum = 4;
2369      Value *Callee;
2370      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
2371        return Error("Invalid INVOKE record");
2372
2373      PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
2374      FunctionType *FTy = !CalleeTy ? 0 :
2375        dyn_cast<FunctionType>(CalleeTy->getElementType());
2376
2377      // Check that the right number of fixed parameters are here.
2378      if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
2379          Record.size() < OpNum+FTy->getNumParams())
2380        return Error("Invalid INVOKE record");
2381
2382      SmallVector<Value*, 16> Ops;
2383      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
2384        Ops.push_back(getValue(Record, OpNum, NextValueNo,
2385                               FTy->getParamType(i)));
2386        if (Ops.back() == 0) return Error("Invalid INVOKE record");
2387      }
2388
2389      if (!FTy->isVarArg()) {
2390        if (Record.size() != OpNum)
2391          return Error("Invalid INVOKE record");
2392      } else {
2393        // Read type/value pairs for varargs params.
2394        while (OpNum != Record.size()) {
2395          Value *Op;
2396          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2397            return Error("Invalid INVOKE record");
2398          Ops.push_back(Op);
2399        }
2400      }
2401
2402      I = InvokeInst::Create(Callee, NormalBB, UnwindBB, Ops);
2403      InstructionList.push_back(I);
2404      cast<InvokeInst>(I)->setCallingConv(
2405        static_cast<CallingConv::ID>(CCInfo));
2406      cast<InvokeInst>(I)->setAttributes(PAL);
2407      break;
2408    }
2409    case bitc::FUNC_CODE_INST_RESUME: { // RESUME: [opval]
2410      unsigned Idx = 0;
2411      Value *Val = 0;
2412      if (getValueTypePair(Record, Idx, NextValueNo, Val))
2413        return Error("Invalid RESUME record");
2414      I = ResumeInst::Create(Val);
2415      InstructionList.push_back(I);
2416      break;
2417    }
2418    case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
2419      I = new UnreachableInst(Context);
2420      InstructionList.push_back(I);
2421      break;
2422    case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
2423      if (Record.size() < 1 || ((Record.size()-1)&1))
2424        return Error("Invalid PHI record");
2425      Type *Ty = getTypeByID(Record[0]);
2426      if (!Ty) return Error("Invalid PHI record");
2427
2428      PHINode *PN = PHINode::Create(Ty, (Record.size()-1)/2);
2429      InstructionList.push_back(PN);
2430
2431      for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
2432        Value *V;
2433        // With the new function encoding, it is possible that operands have
2434        // negative IDs (for forward references).  Use a signed VBR
2435        // representation to keep the encoding small.
2436        if (UseRelativeIDs)
2437          V = getValueSigned(Record, 1+i, NextValueNo, Ty);
2438        else
2439          V = getValue(Record, 1+i, NextValueNo, Ty);
2440        BasicBlock *BB = getBasicBlock(Record[2+i]);
2441        if (!V || !BB) return Error("Invalid PHI record");
2442        PN->addIncoming(V, BB);
2443      }
2444      I = PN;
2445      break;
2446    }
2447
2448    case bitc::FUNC_CODE_INST_LANDINGPAD: {
2449      // LANDINGPAD: [ty, val, val, num, (id0,val0 ...)?]
2450      unsigned Idx = 0;
2451      if (Record.size() < 4)
2452        return Error("Invalid LANDINGPAD record");
2453      Type *Ty = getTypeByID(Record[Idx++]);
2454      if (!Ty) return Error("Invalid LANDINGPAD record");
2455      Value *PersFn = 0;
2456      if (getValueTypePair(Record, Idx, NextValueNo, PersFn))
2457        return Error("Invalid LANDINGPAD record");
2458
2459      bool IsCleanup = !!Record[Idx++];
2460      unsigned NumClauses = Record[Idx++];
2461      LandingPadInst *LP = LandingPadInst::Create(Ty, PersFn, NumClauses);
2462      LP->setCleanup(IsCleanup);
2463      for (unsigned J = 0; J != NumClauses; ++J) {
2464        LandingPadInst::ClauseType CT =
2465          LandingPadInst::ClauseType(Record[Idx++]); (void)CT;
2466        Value *Val;
2467
2468        if (getValueTypePair(Record, Idx, NextValueNo, Val)) {
2469          delete LP;
2470          return Error("Invalid LANDINGPAD record");
2471        }
2472
2473        assert((CT != LandingPadInst::Catch ||
2474                !isa<ArrayType>(Val->getType())) &&
2475               "Catch clause has a invalid type!");
2476        assert((CT != LandingPadInst::Filter ||
2477                isa<ArrayType>(Val->getType())) &&
2478               "Filter clause has invalid type!");
2479        LP->addClause(Val);
2480      }
2481
2482      I = LP;
2483      InstructionList.push_back(I);
2484      break;
2485    }
2486
2487    case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, opty, op, align]
2488      if (Record.size() != 4)
2489        return Error("Invalid ALLOCA record");
2490      PointerType *Ty =
2491        dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
2492      Type *OpTy = getTypeByID(Record[1]);
2493      Value *Size = getFnValueByID(Record[2], OpTy);
2494      unsigned Align = Record[3];
2495      if (!Ty || !Size) return Error("Invalid ALLOCA record");
2496      I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
2497      InstructionList.push_back(I);
2498      break;
2499    }
2500    case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
2501      unsigned OpNum = 0;
2502      Value *Op;
2503      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2504          OpNum+2 != Record.size())
2505        return Error("Invalid LOAD record");
2506
2507      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
2508      InstructionList.push_back(I);
2509      break;
2510    }
2511    case bitc::FUNC_CODE_INST_LOADATOMIC: {
2512       // LOADATOMIC: [opty, op, align, vol, ordering, synchscope]
2513      unsigned OpNum = 0;
2514      Value *Op;
2515      if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2516          OpNum+4 != Record.size())
2517        return Error("Invalid LOADATOMIC record");
2518
2519
2520      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2521      if (Ordering == NotAtomic || Ordering == Release ||
2522          Ordering == AcquireRelease)
2523        return Error("Invalid LOADATOMIC record");
2524      if (Ordering != NotAtomic && Record[OpNum] == 0)
2525        return Error("Invalid LOADATOMIC record");
2526      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2527
2528      I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1,
2529                       Ordering, SynchScope);
2530      InstructionList.push_back(I);
2531      break;
2532    }
2533    case bitc::FUNC_CODE_INST_STORE: { // STORE2:[ptrty, ptr, val, align, vol]
2534      unsigned OpNum = 0;
2535      Value *Val, *Ptr;
2536      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2537          popValue(Record, OpNum, NextValueNo,
2538                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2539          OpNum+2 != Record.size())
2540        return Error("Invalid STORE record");
2541
2542      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
2543      InstructionList.push_back(I);
2544      break;
2545    }
2546    case bitc::FUNC_CODE_INST_STOREATOMIC: {
2547      // STOREATOMIC: [ptrty, ptr, val, align, vol, ordering, synchscope]
2548      unsigned OpNum = 0;
2549      Value *Val, *Ptr;
2550      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2551          popValue(Record, OpNum, NextValueNo,
2552                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2553          OpNum+4 != Record.size())
2554        return Error("Invalid STOREATOMIC record");
2555
2556      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2557      if (Ordering == NotAtomic || Ordering == Acquire ||
2558          Ordering == AcquireRelease)
2559        return Error("Invalid STOREATOMIC record");
2560      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2561      if (Ordering != NotAtomic && Record[OpNum] == 0)
2562        return Error("Invalid STOREATOMIC record");
2563
2564      I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1,
2565                        Ordering, SynchScope);
2566      InstructionList.push_back(I);
2567      break;
2568    }
2569    case bitc::FUNC_CODE_INST_CMPXCHG: {
2570      // CMPXCHG:[ptrty, ptr, cmp, new, vol, ordering, synchscope]
2571      unsigned OpNum = 0;
2572      Value *Ptr, *Cmp, *New;
2573      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2574          popValue(Record, OpNum, NextValueNo,
2575                    cast<PointerType>(Ptr->getType())->getElementType(), Cmp) ||
2576          popValue(Record, OpNum, NextValueNo,
2577                    cast<PointerType>(Ptr->getType())->getElementType(), New) ||
2578          OpNum+3 != Record.size())
2579        return Error("Invalid CMPXCHG record");
2580      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+1]);
2581      if (Ordering == NotAtomic || Ordering == Unordered)
2582        return Error("Invalid CMPXCHG record");
2583      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+2]);
2584      I = new AtomicCmpXchgInst(Ptr, Cmp, New, Ordering, SynchScope);
2585      cast<AtomicCmpXchgInst>(I)->setVolatile(Record[OpNum]);
2586      InstructionList.push_back(I);
2587      break;
2588    }
2589    case bitc::FUNC_CODE_INST_ATOMICRMW: {
2590      // ATOMICRMW:[ptrty, ptr, val, op, vol, ordering, synchscope]
2591      unsigned OpNum = 0;
2592      Value *Ptr, *Val;
2593      if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2594          popValue(Record, OpNum, NextValueNo,
2595                    cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2596          OpNum+4 != Record.size())
2597        return Error("Invalid ATOMICRMW record");
2598      AtomicRMWInst::BinOp Operation = GetDecodedRMWOperation(Record[OpNum]);
2599      if (Operation < AtomicRMWInst::FIRST_BINOP ||
2600          Operation > AtomicRMWInst::LAST_BINOP)
2601        return Error("Invalid ATOMICRMW record");
2602      AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2603      if (Ordering == NotAtomic || Ordering == Unordered)
2604        return Error("Invalid ATOMICRMW record");
2605      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2606      I = new AtomicRMWInst(Operation, Ptr, Val, Ordering, SynchScope);
2607      cast<AtomicRMWInst>(I)->setVolatile(Record[OpNum+1]);
2608      InstructionList.push_back(I);
2609      break;
2610    }
2611    case bitc::FUNC_CODE_INST_FENCE: { // FENCE:[ordering, synchscope]
2612      if (2 != Record.size())
2613        return Error("Invalid FENCE record");
2614      AtomicOrdering Ordering = GetDecodedOrdering(Record[0]);
2615      if (Ordering == NotAtomic || Ordering == Unordered ||
2616          Ordering == Monotonic)
2617        return Error("Invalid FENCE record");
2618      SynchronizationScope SynchScope = GetDecodedSynchScope(Record[1]);
2619      I = new FenceInst(Context, Ordering, SynchScope);
2620      InstructionList.push_back(I);
2621      break;
2622    }
2623    case bitc::FUNC_CODE_INST_CALL: {
2624      // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
2625      if (Record.size() < 3)
2626        return Error("Invalid CALL record");
2627
2628      AttributeSet PAL = getAttributes(Record[0]);
2629      unsigned CCInfo = Record[1];
2630
2631      unsigned OpNum = 2;
2632      Value *Callee;
2633      if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
2634        return Error("Invalid CALL record");
2635
2636      PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
2637      FunctionType *FTy = 0;
2638      if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
2639      if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
2640        return Error("Invalid CALL record");
2641
2642      SmallVector<Value*, 16> Args;
2643      // Read the fixed params.
2644      for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
2645        if (FTy->getParamType(i)->isLabelTy())
2646          Args.push_back(getBasicBlock(Record[OpNum]));
2647        else
2648          Args.push_back(getValue(Record, OpNum, NextValueNo,
2649                                  FTy->getParamType(i)));
2650        if (Args.back() == 0) return Error("Invalid CALL record");
2651      }
2652
2653      // Read type/value pairs for varargs params.
2654      if (!FTy->isVarArg()) {
2655        if (OpNum != Record.size())
2656          return Error("Invalid CALL record");
2657      } else {
2658        while (OpNum != Record.size()) {
2659          Value *Op;
2660          if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2661            return Error("Invalid CALL record");
2662          Args.push_back(Op);
2663        }
2664      }
2665
2666      I = CallInst::Create(Callee, Args);
2667      InstructionList.push_back(I);
2668      cast<CallInst>(I)->setCallingConv(
2669        static_cast<CallingConv::ID>(CCInfo>>1));
2670      cast<CallInst>(I)->setTailCall(CCInfo & 1);
2671      cast<CallInst>(I)->setAttributes(PAL);
2672      break;
2673    }
2674    case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
2675      if (Record.size() < 3)
2676        return Error("Invalid VAARG record");
2677      Type *OpTy = getTypeByID(Record[0]);
2678      Value *Op = getValue(Record, 1, NextValueNo, OpTy);
2679      Type *ResTy = getTypeByID(Record[2]);
2680      if (!OpTy || !Op || !ResTy)
2681        return Error("Invalid VAARG record");
2682      I = new VAArgInst(Op, ResTy);
2683      InstructionList.push_back(I);
2684      break;
2685    }
2686    }
2687
2688    // Add instruction to end of current BB.  If there is no current BB, reject
2689    // this file.
2690    if (CurBB == 0) {
2691      delete I;
2692      return Error("Invalid instruction with no BB");
2693    }
2694    CurBB->getInstList().push_back(I);
2695
2696    // If this was a terminator instruction, move to the next block.
2697    if (isa<TerminatorInst>(I)) {
2698      ++CurBBNo;
2699      CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
2700    }
2701
2702    // Non-void values get registered in the value table for future use.
2703    if (I && !I->getType()->isVoidTy())
2704      ValueList.AssignValue(I, NextValueNo++);
2705  }
2706
2707OutOfRecordLoop:
2708
2709  // Check the function list for unresolved values.
2710  if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
2711    if (A->getParent() == 0) {
2712      // We found at least one unresolved value.  Nuke them all to avoid leaks.
2713      for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
2714        if ((A = dyn_cast<Argument>(ValueList[i])) && A->getParent() == 0) {
2715          A->replaceAllUsesWith(UndefValue::get(A->getType()));
2716          delete A;
2717        }
2718      }
2719      return Error("Never resolved value found in function!");
2720    }
2721  }
2722
2723  // FIXME: Check for unresolved forward-declared metadata references
2724  // and clean up leaks.
2725
2726  // See if anything took the address of blocks in this function.  If so,
2727  // resolve them now.
2728  DenseMap<Function*, std::vector<BlockAddrRefTy> >::iterator BAFRI =
2729    BlockAddrFwdRefs.find(F);
2730  if (BAFRI != BlockAddrFwdRefs.end()) {
2731    std::vector<BlockAddrRefTy> &RefList = BAFRI->second;
2732    for (unsigned i = 0, e = RefList.size(); i != e; ++i) {
2733      unsigned BlockIdx = RefList[i].first;
2734      if (BlockIdx >= FunctionBBs.size())
2735        return Error("Invalid blockaddress block #");
2736
2737      GlobalVariable *FwdRef = RefList[i].second;
2738      FwdRef->replaceAllUsesWith(BlockAddress::get(F, FunctionBBs[BlockIdx]));
2739      FwdRef->eraseFromParent();
2740    }
2741
2742    BlockAddrFwdRefs.erase(BAFRI);
2743  }
2744
2745  // Trim the value list down to the size it was before we parsed this function.
2746  ValueList.shrinkTo(ModuleValueListSize);
2747  MDValueList.shrinkTo(ModuleMDValueListSize);
2748  std::vector<BasicBlock*>().swap(FunctionBBs);
2749  return false;
2750}
2751
2752/// FindFunctionInStream - Find the function body in the bitcode stream
2753bool BitcodeReader::FindFunctionInStream(Function *F,
2754       DenseMap<Function*, uint64_t>::iterator DeferredFunctionInfoIterator) {
2755  while (DeferredFunctionInfoIterator->second == 0) {
2756    if (Stream.AtEndOfStream())
2757      return Error("Could not find Function in stream");
2758    // ParseModule will parse the next body in the stream and set its
2759    // position in the DeferredFunctionInfo map.
2760    if (ParseModule(true)) return true;
2761  }
2762  return false;
2763}
2764
2765//===----------------------------------------------------------------------===//
2766// GVMaterializer implementation
2767//===----------------------------------------------------------------------===//
2768
2769
2770bool BitcodeReader::isMaterializable(const GlobalValue *GV) const {
2771  if (const Function *F = dyn_cast<Function>(GV)) {
2772    return F->isDeclaration() &&
2773      DeferredFunctionInfo.count(const_cast<Function*>(F));
2774  }
2775  return false;
2776}
2777
2778bool BitcodeReader::Materialize(GlobalValue *GV, std::string *ErrInfo) {
2779  Function *F = dyn_cast<Function>(GV);
2780  // If it's not a function or is already material, ignore the request.
2781  if (!F || !F->isMaterializable()) return false;
2782
2783  DenseMap<Function*, uint64_t>::iterator DFII = DeferredFunctionInfo.find(F);
2784  assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
2785  // If its position is recorded as 0, its body is somewhere in the stream
2786  // but we haven't seen it yet.
2787  if (DFII->second == 0)
2788    if (LazyStreamer && FindFunctionInStream(F, DFII)) return true;
2789
2790  // Move the bit stream to the saved position of the deferred function body.
2791  Stream.JumpToBit(DFII->second);
2792
2793  if (ParseFunctionBody(F)) {
2794    if (ErrInfo) *ErrInfo = ErrorString;
2795    return true;
2796  }
2797
2798  // Upgrade any old intrinsic calls in the function.
2799  for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
2800       E = UpgradedIntrinsics.end(); I != E; ++I) {
2801    if (I->first != I->second) {
2802      for (Value::use_iterator UI = I->first->use_begin(),
2803           UE = I->first->use_end(); UI != UE; ) {
2804        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2805          UpgradeIntrinsicCall(CI, I->second);
2806      }
2807    }
2808  }
2809
2810  return false;
2811}
2812
2813bool BitcodeReader::isDematerializable(const GlobalValue *GV) const {
2814  const Function *F = dyn_cast<Function>(GV);
2815  if (!F || F->isDeclaration())
2816    return false;
2817  return DeferredFunctionInfo.count(const_cast<Function*>(F));
2818}
2819
2820void BitcodeReader::Dematerialize(GlobalValue *GV) {
2821  Function *F = dyn_cast<Function>(GV);
2822  // If this function isn't dematerializable, this is a noop.
2823  if (!F || !isDematerializable(F))
2824    return;
2825
2826  assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
2827
2828  // Just forget the function body, we can remat it later.
2829  F->deleteBody();
2830}
2831
2832
2833bool BitcodeReader::MaterializeModule(Module *M, std::string *ErrInfo) {
2834  assert(M == TheModule &&
2835         "Can only Materialize the Module this BitcodeReader is attached to.");
2836  // Iterate over the module, deserializing any functions that are still on
2837  // disk.
2838  for (Module::iterator F = TheModule->begin(), E = TheModule->end();
2839       F != E; ++F)
2840    if (F->isMaterializable() &&
2841        Materialize(F, ErrInfo))
2842      return true;
2843
2844  // At this point, if there are any function bodies, the current bit is
2845  // pointing to the END_BLOCK record after them. Now make sure the rest
2846  // of the bits in the module have been read.
2847  if (NextUnreadBit)
2848    ParseModule(true);
2849
2850  // Upgrade any intrinsic calls that slipped through (should not happen!) and
2851  // delete the old functions to clean up. We can't do this unless the entire
2852  // module is materialized because there could always be another function body
2853  // with calls to the old function.
2854  for (std::vector<std::pair<Function*, Function*> >::iterator I =
2855       UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
2856    if (I->first != I->second) {
2857      for (Value::use_iterator UI = I->first->use_begin(),
2858           UE = I->first->use_end(); UI != UE; ) {
2859        if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2860          UpgradeIntrinsicCall(CI, I->second);
2861      }
2862      if (!I->first->use_empty())
2863        I->first->replaceAllUsesWith(I->second);
2864      I->first->eraseFromParent();
2865    }
2866  }
2867  std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
2868
2869  return false;
2870}
2871
2872bool BitcodeReader::InitStream() {
2873  if (LazyStreamer) return InitLazyStream();
2874  return InitStreamFromBuffer();
2875}
2876
2877bool BitcodeReader::InitStreamFromBuffer() {
2878  const unsigned char *BufPtr = (const unsigned char*)Buffer->getBufferStart();
2879  const unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
2880
2881  if (Buffer->getBufferSize() & 3) {
2882    if (!isRawBitcode(BufPtr, BufEnd) && !isBitcodeWrapper(BufPtr, BufEnd))
2883      return Error("Invalid bitcode signature");
2884    else
2885      return Error("Bitcode stream should be a multiple of 4 bytes in length");
2886  }
2887
2888  // If we have a wrapper header, parse it and ignore the non-bc file contents.
2889  // The magic number is 0x0B17C0DE stored in little endian.
2890  if (isBitcodeWrapper(BufPtr, BufEnd))
2891    if (SkipBitcodeWrapperHeader(BufPtr, BufEnd, true))
2892      return Error("Invalid bitcode wrapper header");
2893
2894  StreamFile.reset(new BitstreamReader(BufPtr, BufEnd));
2895  Stream.init(*StreamFile);
2896
2897  return false;
2898}
2899
2900bool BitcodeReader::InitLazyStream() {
2901  // Check and strip off the bitcode wrapper; BitstreamReader expects never to
2902  // see it.
2903  StreamingMemoryObject *Bytes = new StreamingMemoryObject(LazyStreamer);
2904  StreamFile.reset(new BitstreamReader(Bytes));
2905  Stream.init(*StreamFile);
2906
2907  unsigned char buf[16];
2908  if (Bytes->readBytes(0, 16, buf, NULL) == -1)
2909    return Error("Bitcode stream must be at least 16 bytes in length");
2910
2911  if (!isBitcode(buf, buf + 16))
2912    return Error("Invalid bitcode signature");
2913
2914  if (isBitcodeWrapper(buf, buf + 4)) {
2915    const unsigned char *bitcodeStart = buf;
2916    const unsigned char *bitcodeEnd = buf + 16;
2917    SkipBitcodeWrapperHeader(bitcodeStart, bitcodeEnd, false);
2918    Bytes->dropLeadingBytes(bitcodeStart - buf);
2919    Bytes->setKnownObjectSize(bitcodeEnd - bitcodeStart);
2920  }
2921  return false;
2922}
2923
2924//===----------------------------------------------------------------------===//
2925// External interface
2926//===----------------------------------------------------------------------===//
2927
2928/// getLazyBitcodeModule - lazy function-at-a-time loading from a file.
2929///
2930Module *llvm::getLazyBitcodeModule(MemoryBuffer *Buffer,
2931                                   LLVMContext& Context,
2932                                   std::string *ErrMsg) {
2933  Module *M = new Module(Buffer->getBufferIdentifier(), Context);
2934  BitcodeReader *R = new BitcodeReader(Buffer, Context);
2935  M->setMaterializer(R);
2936  if (R->ParseBitcodeInto(M)) {
2937    if (ErrMsg)
2938      *ErrMsg = R->getErrorString();
2939
2940    delete M;  // Also deletes R.
2941    return 0;
2942  }
2943  // Have the BitcodeReader dtor delete 'Buffer'.
2944  R->setBufferOwned(true);
2945
2946  R->materializeForwardReferencedFunctions();
2947
2948  return M;
2949}
2950
2951
2952Module *llvm::getStreamedBitcodeModule(const std::string &name,
2953                                       DataStreamer *streamer,
2954                                       LLVMContext &Context,
2955                                       std::string *ErrMsg) {
2956  Module *M = new Module(name, Context);
2957  BitcodeReader *R = new BitcodeReader(streamer, Context);
2958  M->setMaterializer(R);
2959  if (R->ParseBitcodeInto(M)) {
2960    if (ErrMsg)
2961      *ErrMsg = R->getErrorString();
2962    delete M;  // Also deletes R.
2963    return 0;
2964  }
2965  R->setBufferOwned(false); // no buffer to delete
2966  return M;
2967}
2968
2969/// ParseBitcodeFile - Read the specified bitcode file, returning the module.
2970/// If an error occurs, return null and fill in *ErrMsg if non-null.
2971Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, LLVMContext& Context,
2972                               std::string *ErrMsg){
2973  Module *M = getLazyBitcodeModule(Buffer, Context, ErrMsg);
2974  if (!M) return 0;
2975
2976  // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
2977  // there was an error.
2978  static_cast<BitcodeReader*>(M->getMaterializer())->setBufferOwned(false);
2979
2980  // Read in the entire module, and destroy the BitcodeReader.
2981  if (M->MaterializeAllPermanently(ErrMsg)) {
2982    delete M;
2983    return 0;
2984  }
2985
2986  // TODO: Restore the use-lists to the in-memory state when the bitcode was
2987  // written.  We must defer until the Module has been fully materialized.
2988
2989  return M;
2990}
2991
2992std::string llvm::getBitcodeTargetTriple(MemoryBuffer *Buffer,
2993                                         LLVMContext& Context,
2994                                         std::string *ErrMsg) {
2995  BitcodeReader *R = new BitcodeReader(Buffer, Context);
2996  // Don't let the BitcodeReader dtor delete 'Buffer'.
2997  R->setBufferOwned(false);
2998
2999  std::string Triple("");
3000  if (R->ParseTriple(Triple))
3001    if (ErrMsg)
3002      *ErrMsg = R->getErrorString();
3003
3004  delete R;
3005  return Triple;
3006}
3007