xref: /llvm-project/llvm/lib/Bitcode/Reader/BitcodeReader.cpp (revision cc3aaf18366b46dfe6580e1ef652108d4a665b50)
1 //===- BitcodeReader.cpp - Internal BitcodeReader implementation ----------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This header defines the BitcodeReader class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/Bitcode/ReaderWriter.h"
15 #include "BitcodeReader.h"
16 #include "llvm/Constants.h"
17 #include "llvm/DerivedTypes.h"
18 #include "llvm/InlineAsm.h"
19 #include "llvm/IntrinsicInst.h"
20 #include "llvm/Module.h"
21 #include "llvm/Operator.h"
22 #include "llvm/AutoUpgrade.h"
23 #include "llvm/ADT/SmallString.h"
24 #include "llvm/ADT/SmallVector.h"
25 #include "llvm/Support/MathExtras.h"
26 #include "llvm/Support/MemoryBuffer.h"
27 #include "llvm/OperandTraits.h"
28 using namespace llvm;
29 
30 void BitcodeReader::materializeForwardReferencedFunctions() {
31   while (!BlockAddrFwdRefs.empty()) {
32     Function *F = BlockAddrFwdRefs.begin()->first;
33     F->Materialize();
34   }
35 }
36 
37 void BitcodeReader::FreeState() {
38   if (BufferOwned)
39     delete Buffer;
40   Buffer = 0;
41   std::vector<Type*>().swap(TypeList);
42   ValueList.clear();
43   MDValueList.clear();
44 
45   std::vector<AttrListPtr>().swap(MAttributes);
46   std::vector<BasicBlock*>().swap(FunctionBBs);
47   std::vector<Function*>().swap(FunctionsWithBodies);
48   DeferredFunctionInfo.clear();
49   MDKindMap.clear();
50 }
51 
52 //===----------------------------------------------------------------------===//
53 //  Helper functions to implement forward reference resolution, etc.
54 //===----------------------------------------------------------------------===//
55 
56 /// ConvertToString - Convert a string from a record into an std::string, return
57 /// true on failure.
58 template<typename StrTy>
59 static bool ConvertToString(SmallVector<uint64_t, 64> &Record, unsigned Idx,
60                             StrTy &Result) {
61   if (Idx > Record.size())
62     return true;
63 
64   for (unsigned i = Idx, e = Record.size(); i != e; ++i)
65     Result += (char)Record[i];
66   return false;
67 }
68 
69 static GlobalValue::LinkageTypes GetDecodedLinkage(unsigned Val) {
70   switch (Val) {
71   default: // Map unknown/new linkages to external
72   case 0:  return GlobalValue::ExternalLinkage;
73   case 1:  return GlobalValue::WeakAnyLinkage;
74   case 2:  return GlobalValue::AppendingLinkage;
75   case 3:  return GlobalValue::InternalLinkage;
76   case 4:  return GlobalValue::LinkOnceAnyLinkage;
77   case 5:  return GlobalValue::DLLImportLinkage;
78   case 6:  return GlobalValue::DLLExportLinkage;
79   case 7:  return GlobalValue::ExternalWeakLinkage;
80   case 8:  return GlobalValue::CommonLinkage;
81   case 9:  return GlobalValue::PrivateLinkage;
82   case 10: return GlobalValue::WeakODRLinkage;
83   case 11: return GlobalValue::LinkOnceODRLinkage;
84   case 12: return GlobalValue::AvailableExternallyLinkage;
85   case 13: return GlobalValue::LinkerPrivateLinkage;
86   case 14: return GlobalValue::LinkerPrivateWeakLinkage;
87   case 15: return GlobalValue::LinkerPrivateWeakDefAutoLinkage;
88   }
89 }
90 
91 static GlobalValue::VisibilityTypes GetDecodedVisibility(unsigned Val) {
92   switch (Val) {
93   default: // Map unknown visibilities to default.
94   case 0: return GlobalValue::DefaultVisibility;
95   case 1: return GlobalValue::HiddenVisibility;
96   case 2: return GlobalValue::ProtectedVisibility;
97   }
98 }
99 
100 static int GetDecodedCastOpcode(unsigned Val) {
101   switch (Val) {
102   default: return -1;
103   case bitc::CAST_TRUNC   : return Instruction::Trunc;
104   case bitc::CAST_ZEXT    : return Instruction::ZExt;
105   case bitc::CAST_SEXT    : return Instruction::SExt;
106   case bitc::CAST_FPTOUI  : return Instruction::FPToUI;
107   case bitc::CAST_FPTOSI  : return Instruction::FPToSI;
108   case bitc::CAST_UITOFP  : return Instruction::UIToFP;
109   case bitc::CAST_SITOFP  : return Instruction::SIToFP;
110   case bitc::CAST_FPTRUNC : return Instruction::FPTrunc;
111   case bitc::CAST_FPEXT   : return Instruction::FPExt;
112   case bitc::CAST_PTRTOINT: return Instruction::PtrToInt;
113   case bitc::CAST_INTTOPTR: return Instruction::IntToPtr;
114   case bitc::CAST_BITCAST : return Instruction::BitCast;
115   }
116 }
117 static int GetDecodedBinaryOpcode(unsigned Val, Type *Ty) {
118   switch (Val) {
119   default: return -1;
120   case bitc::BINOP_ADD:
121     return Ty->isFPOrFPVectorTy() ? Instruction::FAdd : Instruction::Add;
122   case bitc::BINOP_SUB:
123     return Ty->isFPOrFPVectorTy() ? Instruction::FSub : Instruction::Sub;
124   case bitc::BINOP_MUL:
125     return Ty->isFPOrFPVectorTy() ? Instruction::FMul : Instruction::Mul;
126   case bitc::BINOP_UDIV: return Instruction::UDiv;
127   case bitc::BINOP_SDIV:
128     return Ty->isFPOrFPVectorTy() ? Instruction::FDiv : Instruction::SDiv;
129   case bitc::BINOP_UREM: return Instruction::URem;
130   case bitc::BINOP_SREM:
131     return Ty->isFPOrFPVectorTy() ? Instruction::FRem : Instruction::SRem;
132   case bitc::BINOP_SHL:  return Instruction::Shl;
133   case bitc::BINOP_LSHR: return Instruction::LShr;
134   case bitc::BINOP_ASHR: return Instruction::AShr;
135   case bitc::BINOP_AND:  return Instruction::And;
136   case bitc::BINOP_OR:   return Instruction::Or;
137   case bitc::BINOP_XOR:  return Instruction::Xor;
138   }
139 }
140 
141 static AtomicRMWInst::BinOp GetDecodedRMWOperation(unsigned Val) {
142   switch (Val) {
143   default: return AtomicRMWInst::BAD_BINOP;
144   case bitc::RMW_XCHG: return AtomicRMWInst::Xchg;
145   case bitc::RMW_ADD: return AtomicRMWInst::Add;
146   case bitc::RMW_SUB: return AtomicRMWInst::Sub;
147   case bitc::RMW_AND: return AtomicRMWInst::And;
148   case bitc::RMW_NAND: return AtomicRMWInst::Nand;
149   case bitc::RMW_OR: return AtomicRMWInst::Or;
150   case bitc::RMW_XOR: return AtomicRMWInst::Xor;
151   case bitc::RMW_MAX: return AtomicRMWInst::Max;
152   case bitc::RMW_MIN: return AtomicRMWInst::Min;
153   case bitc::RMW_UMAX: return AtomicRMWInst::UMax;
154   case bitc::RMW_UMIN: return AtomicRMWInst::UMin;
155   }
156 }
157 
158 static AtomicOrdering GetDecodedOrdering(unsigned Val) {
159   switch (Val) {
160   case bitc::ORDERING_NOTATOMIC: return NotAtomic;
161   case bitc::ORDERING_UNORDERED: return Unordered;
162   case bitc::ORDERING_MONOTONIC: return Monotonic;
163   case bitc::ORDERING_ACQUIRE: return Acquire;
164   case bitc::ORDERING_RELEASE: return Release;
165   case bitc::ORDERING_ACQREL: return AcquireRelease;
166   default: // Map unknown orderings to sequentially-consistent.
167   case bitc::ORDERING_SEQCST: return SequentiallyConsistent;
168   }
169 }
170 
171 static SynchronizationScope GetDecodedSynchScope(unsigned Val) {
172   switch (Val) {
173   case bitc::SYNCHSCOPE_SINGLETHREAD: return SingleThread;
174   default: // Map unknown scopes to cross-thread.
175   case bitc::SYNCHSCOPE_CROSSTHREAD: return CrossThread;
176   }
177 }
178 
179 namespace llvm {
180 namespace {
181   /// @brief A class for maintaining the slot number definition
182   /// as a placeholder for the actual definition for forward constants defs.
183   class ConstantPlaceHolder : public ConstantExpr {
184     void operator=(const ConstantPlaceHolder &); // DO NOT IMPLEMENT
185   public:
186     // allocate space for exactly one operand
187     void *operator new(size_t s) {
188       return User::operator new(s, 1);
189     }
190     explicit ConstantPlaceHolder(Type *Ty, LLVMContext& Context)
191       : ConstantExpr(Ty, Instruction::UserOp1, &Op<0>(), 1) {
192       Op<0>() = UndefValue::get(Type::getInt32Ty(Context));
193     }
194 
195     /// @brief Methods to support type inquiry through isa, cast, and dyn_cast.
196     //static inline bool classof(const ConstantPlaceHolder *) { return true; }
197     static bool classof(const Value *V) {
198       return isa<ConstantExpr>(V) &&
199              cast<ConstantExpr>(V)->getOpcode() == Instruction::UserOp1;
200     }
201 
202 
203     /// Provide fast operand accessors
204     //DECLARE_TRANSPARENT_OPERAND_ACCESSORS(Value);
205   };
206 }
207 
208 // FIXME: can we inherit this from ConstantExpr?
209 template <>
210 struct OperandTraits<ConstantPlaceHolder> :
211   public FixedNumOperandTraits<ConstantPlaceHolder, 1> {
212 };
213 }
214 
215 
216 void BitcodeReaderValueList::AssignValue(Value *V, unsigned Idx) {
217   if (Idx == size()) {
218     push_back(V);
219     return;
220   }
221 
222   if (Idx >= size())
223     resize(Idx+1);
224 
225   WeakVH &OldV = ValuePtrs[Idx];
226   if (OldV == 0) {
227     OldV = V;
228     return;
229   }
230 
231   // Handle constants and non-constants (e.g. instrs) differently for
232   // efficiency.
233   if (Constant *PHC = dyn_cast<Constant>(&*OldV)) {
234     ResolveConstants.push_back(std::make_pair(PHC, Idx));
235     OldV = V;
236   } else {
237     // If there was a forward reference to this value, replace it.
238     Value *PrevVal = OldV;
239     OldV->replaceAllUsesWith(V);
240     delete PrevVal;
241   }
242 }
243 
244 
245 Constant *BitcodeReaderValueList::getConstantFwdRef(unsigned Idx,
246                                                     Type *Ty) {
247   if (Idx >= size())
248     resize(Idx + 1);
249 
250   if (Value *V = ValuePtrs[Idx]) {
251     assert(Ty == V->getType() && "Type mismatch in constant table!");
252     return cast<Constant>(V);
253   }
254 
255   // Create and return a placeholder, which will later be RAUW'd.
256   Constant *C = new ConstantPlaceHolder(Ty, Context);
257   ValuePtrs[Idx] = C;
258   return C;
259 }
260 
261 Value *BitcodeReaderValueList::getValueFwdRef(unsigned Idx, Type *Ty) {
262   if (Idx >= size())
263     resize(Idx + 1);
264 
265   if (Value *V = ValuePtrs[Idx]) {
266     assert((Ty == 0 || Ty == V->getType()) && "Type mismatch in value table!");
267     return V;
268   }
269 
270   // No type specified, must be invalid reference.
271   if (Ty == 0) return 0;
272 
273   // Create and return a placeholder, which will later be RAUW'd.
274   Value *V = new Argument(Ty);
275   ValuePtrs[Idx] = V;
276   return V;
277 }
278 
279 /// ResolveConstantForwardRefs - Once all constants are read, this method bulk
280 /// resolves any forward references.  The idea behind this is that we sometimes
281 /// get constants (such as large arrays) which reference *many* forward ref
282 /// constants.  Replacing each of these causes a lot of thrashing when
283 /// building/reuniquing the constant.  Instead of doing this, we look at all the
284 /// uses and rewrite all the place holders at once for any constant that uses
285 /// a placeholder.
286 void BitcodeReaderValueList::ResolveConstantForwardRefs() {
287   // Sort the values by-pointer so that they are efficient to look up with a
288   // binary search.
289   std::sort(ResolveConstants.begin(), ResolveConstants.end());
290 
291   SmallVector<Constant*, 64> NewOps;
292 
293   while (!ResolveConstants.empty()) {
294     Value *RealVal = operator[](ResolveConstants.back().second);
295     Constant *Placeholder = ResolveConstants.back().first;
296     ResolveConstants.pop_back();
297 
298     // Loop over all users of the placeholder, updating them to reference the
299     // new value.  If they reference more than one placeholder, update them all
300     // at once.
301     while (!Placeholder->use_empty()) {
302       Value::use_iterator UI = Placeholder->use_begin();
303       User *U = *UI;
304 
305       // If the using object isn't uniqued, just update the operands.  This
306       // handles instructions and initializers for global variables.
307       if (!isa<Constant>(U) || isa<GlobalValue>(U)) {
308         UI.getUse().set(RealVal);
309         continue;
310       }
311 
312       // Otherwise, we have a constant that uses the placeholder.  Replace that
313       // constant with a new constant that has *all* placeholder uses updated.
314       Constant *UserC = cast<Constant>(U);
315       for (User::op_iterator I = UserC->op_begin(), E = UserC->op_end();
316            I != E; ++I) {
317         Value *NewOp;
318         if (!isa<ConstantPlaceHolder>(*I)) {
319           // Not a placeholder reference.
320           NewOp = *I;
321         } else if (*I == Placeholder) {
322           // Common case is that it just references this one placeholder.
323           NewOp = RealVal;
324         } else {
325           // Otherwise, look up the placeholder in ResolveConstants.
326           ResolveConstantsTy::iterator It =
327             std::lower_bound(ResolveConstants.begin(), ResolveConstants.end(),
328                              std::pair<Constant*, unsigned>(cast<Constant>(*I),
329                                                             0));
330           assert(It != ResolveConstants.end() && It->first == *I);
331           NewOp = operator[](It->second);
332         }
333 
334         NewOps.push_back(cast<Constant>(NewOp));
335       }
336 
337       // Make the new constant.
338       Constant *NewC;
339       if (ConstantArray *UserCA = dyn_cast<ConstantArray>(UserC)) {
340         NewC = ConstantArray::get(UserCA->getType(), NewOps);
341       } else if (ConstantStruct *UserCS = dyn_cast<ConstantStruct>(UserC)) {
342         NewC = ConstantStruct::get(UserCS->getType(), NewOps);
343       } else if (isa<ConstantVector>(UserC)) {
344         NewC = ConstantVector::get(NewOps);
345       } else {
346         assert(isa<ConstantExpr>(UserC) && "Must be a ConstantExpr.");
347         NewC = cast<ConstantExpr>(UserC)->getWithOperands(NewOps);
348       }
349 
350       UserC->replaceAllUsesWith(NewC);
351       UserC->destroyConstant();
352       NewOps.clear();
353     }
354 
355     // Update all ValueHandles, they should be the only users at this point.
356     Placeholder->replaceAllUsesWith(RealVal);
357     delete Placeholder;
358   }
359 }
360 
361 void BitcodeReaderMDValueList::AssignValue(Value *V, unsigned Idx) {
362   if (Idx == size()) {
363     push_back(V);
364     return;
365   }
366 
367   if (Idx >= size())
368     resize(Idx+1);
369 
370   WeakVH &OldV = MDValuePtrs[Idx];
371   if (OldV == 0) {
372     OldV = V;
373     return;
374   }
375 
376   // If there was a forward reference to this value, replace it.
377   MDNode *PrevVal = cast<MDNode>(OldV);
378   OldV->replaceAllUsesWith(V);
379   MDNode::deleteTemporary(PrevVal);
380   // Deleting PrevVal sets Idx value in MDValuePtrs to null. Set new
381   // value for Idx.
382   MDValuePtrs[Idx] = V;
383 }
384 
385 Value *BitcodeReaderMDValueList::getValueFwdRef(unsigned Idx) {
386   if (Idx >= size())
387     resize(Idx + 1);
388 
389   if (Value *V = MDValuePtrs[Idx]) {
390     assert(V->getType()->isMetadataTy() && "Type mismatch in value table!");
391     return V;
392   }
393 
394   // Create and return a placeholder, which will later be RAUW'd.
395   Value *V = MDNode::getTemporary(Context, ArrayRef<Value*>());
396   MDValuePtrs[Idx] = V;
397   return V;
398 }
399 
400 Type *BitcodeReader::getTypeByID(unsigned ID) {
401   // The type table size is always specified correctly.
402   if (ID >= TypeList.size())
403     return 0;
404 
405   if (Type *Ty = TypeList[ID])
406     return Ty;
407 
408   // If we have a forward reference, the only possible case is when it is to a
409   // named struct.  Just create a placeholder for now.
410   return TypeList[ID] = StructType::create(Context);
411 }
412 
413 
414 //===----------------------------------------------------------------------===//
415 //  Functions for parsing blocks from the bitcode file
416 //===----------------------------------------------------------------------===//
417 
418 bool BitcodeReader::ParseAttributeBlock() {
419   if (Stream.EnterSubBlock(bitc::PARAMATTR_BLOCK_ID))
420     return Error("Malformed block record");
421 
422   if (!MAttributes.empty())
423     return Error("Multiple PARAMATTR blocks found!");
424 
425   SmallVector<uint64_t, 64> Record;
426 
427   SmallVector<AttributeWithIndex, 8> Attrs;
428 
429   // Read all the records.
430   while (1) {
431     unsigned Code = Stream.ReadCode();
432     if (Code == bitc::END_BLOCK) {
433       if (Stream.ReadBlockEnd())
434         return Error("Error at end of PARAMATTR block");
435       return false;
436     }
437 
438     if (Code == bitc::ENTER_SUBBLOCK) {
439       // No known subblocks, always skip them.
440       Stream.ReadSubBlockID();
441       if (Stream.SkipBlock())
442         return Error("Malformed block record");
443       continue;
444     }
445 
446     if (Code == bitc::DEFINE_ABBREV) {
447       Stream.ReadAbbrevRecord();
448       continue;
449     }
450 
451     // Read a record.
452     Record.clear();
453     switch (Stream.ReadRecord(Code, Record)) {
454     default:  // Default behavior: ignore.
455       break;
456     case bitc::PARAMATTR_CODE_ENTRY: { // ENTRY: [paramidx0, attr0, ...]
457       if (Record.size() & 1)
458         return Error("Invalid ENTRY record");
459 
460       // FIXME : Remove this autoupgrade code in LLVM 3.0.
461       // If Function attributes are using index 0 then transfer them
462       // to index ~0. Index 0 is used for return value attributes but used to be
463       // used for function attributes.
464       Attributes RetAttribute;
465       Attributes FnAttribute;
466       for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
467         // FIXME: remove in LLVM 3.0
468         // The alignment is stored as a 16-bit raw value from bits 31--16.
469         // We shift the bits above 31 down by 11 bits.
470 
471         unsigned Alignment = (Record[i+1] & (0xffffull << 16)) >> 16;
472         if (Alignment && !isPowerOf2_32(Alignment))
473           return Error("Alignment is not a power of two.");
474 
475         Attributes ReconstitutedAttr(Record[i+1] & 0xffff);
476         if (Alignment)
477           ReconstitutedAttr |= Attribute::constructAlignmentFromInt(Alignment);
478         ReconstitutedAttr |=
479             Attributes((Record[i+1] & (0xffffull << 32)) >> 11);
480 
481         Record[i+1] = ReconstitutedAttr.Raw();
482         if (Record[i] == 0)
483           RetAttribute = ReconstitutedAttr;
484         else if (Record[i] == ~0U)
485           FnAttribute = ReconstitutedAttr;
486       }
487 
488       Attributes OldRetAttrs = (Attribute::NoUnwind|Attribute::NoReturn|
489                               Attribute::ReadOnly|Attribute::ReadNone);
490 
491       if (FnAttribute == Attribute::None && RetAttribute != Attribute::None &&
492           (RetAttribute & OldRetAttrs)) {
493         if (FnAttribute == Attribute::None) { // add a slot so they get added.
494           Record.push_back(~0U);
495           Record.push_back(0);
496         }
497 
498         FnAttribute  |= RetAttribute & OldRetAttrs;
499         RetAttribute &= ~OldRetAttrs;
500       }
501 
502       for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
503         if (Record[i] == 0) {
504           if (RetAttribute != Attribute::None)
505             Attrs.push_back(AttributeWithIndex::get(0, RetAttribute));
506         } else if (Record[i] == ~0U) {
507           if (FnAttribute != Attribute::None)
508             Attrs.push_back(AttributeWithIndex::get(~0U, FnAttribute));
509         } else if (Attributes(Record[i+1]) != Attribute::None)
510           Attrs.push_back(AttributeWithIndex::get(Record[i],
511                                                   Attributes(Record[i+1])));
512       }
513 
514       MAttributes.push_back(AttrListPtr::get(Attrs.begin(), Attrs.end()));
515       Attrs.clear();
516       break;
517     }
518     }
519   }
520 }
521 
522 bool BitcodeReader::ParseTypeTable() {
523   if (Stream.EnterSubBlock(bitc::TYPE_BLOCK_ID_NEW))
524     return Error("Malformed block record");
525 
526   return ParseTypeTableBody();
527 }
528 
529 bool BitcodeReader::ParseTypeTableBody() {
530   if (!TypeList.empty())
531     return Error("Multiple TYPE_BLOCKs found!");
532 
533   SmallVector<uint64_t, 64> Record;
534   unsigned NumRecords = 0;
535 
536   SmallString<64> TypeName;
537 
538   // Read all the records for this type table.
539   while (1) {
540     unsigned Code = Stream.ReadCode();
541     if (Code == bitc::END_BLOCK) {
542       if (NumRecords != TypeList.size())
543         return Error("Invalid type forward reference in TYPE_BLOCK");
544       if (Stream.ReadBlockEnd())
545         return Error("Error at end of type table block");
546       return false;
547     }
548 
549     if (Code == bitc::ENTER_SUBBLOCK) {
550       // No known subblocks, always skip them.
551       Stream.ReadSubBlockID();
552       if (Stream.SkipBlock())
553         return Error("Malformed block record");
554       continue;
555     }
556 
557     if (Code == bitc::DEFINE_ABBREV) {
558       Stream.ReadAbbrevRecord();
559       continue;
560     }
561 
562     // Read a record.
563     Record.clear();
564     Type *ResultTy = 0;
565     switch (Stream.ReadRecord(Code, Record)) {
566     default: return Error("unknown type in type table");
567     case bitc::TYPE_CODE_NUMENTRY: // TYPE_CODE_NUMENTRY: [numentries]
568       // TYPE_CODE_NUMENTRY contains a count of the number of types in the
569       // type list.  This allows us to reserve space.
570       if (Record.size() < 1)
571         return Error("Invalid TYPE_CODE_NUMENTRY record");
572       TypeList.resize(Record[0]);
573       continue;
574     case bitc::TYPE_CODE_VOID:      // VOID
575       ResultTy = Type::getVoidTy(Context);
576       break;
577     case bitc::TYPE_CODE_HALF:     // HALF
578       ResultTy = Type::getHalfTy(Context);
579       break;
580     case bitc::TYPE_CODE_FLOAT:     // FLOAT
581       ResultTy = Type::getFloatTy(Context);
582       break;
583     case bitc::TYPE_CODE_DOUBLE:    // DOUBLE
584       ResultTy = Type::getDoubleTy(Context);
585       break;
586     case bitc::TYPE_CODE_X86_FP80:  // X86_FP80
587       ResultTy = Type::getX86_FP80Ty(Context);
588       break;
589     case bitc::TYPE_CODE_FP128:     // FP128
590       ResultTy = Type::getFP128Ty(Context);
591       break;
592     case bitc::TYPE_CODE_PPC_FP128: // PPC_FP128
593       ResultTy = Type::getPPC_FP128Ty(Context);
594       break;
595     case bitc::TYPE_CODE_LABEL:     // LABEL
596       ResultTy = Type::getLabelTy(Context);
597       break;
598     case bitc::TYPE_CODE_METADATA:  // METADATA
599       ResultTy = Type::getMetadataTy(Context);
600       break;
601     case bitc::TYPE_CODE_X86_MMX:   // X86_MMX
602       ResultTy = Type::getX86_MMXTy(Context);
603       break;
604     case bitc::TYPE_CODE_INTEGER:   // INTEGER: [width]
605       if (Record.size() < 1)
606         return Error("Invalid Integer type record");
607 
608       ResultTy = IntegerType::get(Context, Record[0]);
609       break;
610     case bitc::TYPE_CODE_POINTER: { // POINTER: [pointee type] or
611                                     //          [pointee type, address space]
612       if (Record.size() < 1)
613         return Error("Invalid POINTER type record");
614       unsigned AddressSpace = 0;
615       if (Record.size() == 2)
616         AddressSpace = Record[1];
617       ResultTy = getTypeByID(Record[0]);
618       if (ResultTy == 0) return Error("invalid element type in pointer type");
619       ResultTy = PointerType::get(ResultTy, AddressSpace);
620       break;
621     }
622     case bitc::TYPE_CODE_FUNCTION_OLD: {
623       // FIXME: attrid is dead, remove it in LLVM 3.0
624       // FUNCTION: [vararg, attrid, retty, paramty x N]
625       if (Record.size() < 3)
626         return Error("Invalid FUNCTION type record");
627       SmallVector<Type*, 8> ArgTys;
628       for (unsigned i = 3, e = Record.size(); i != e; ++i) {
629         if (Type *T = getTypeByID(Record[i]))
630           ArgTys.push_back(T);
631         else
632           break;
633       }
634 
635       ResultTy = getTypeByID(Record[2]);
636       if (ResultTy == 0 || ArgTys.size() < Record.size()-3)
637         return Error("invalid type in function type");
638 
639       ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
640       break;
641     }
642     case bitc::TYPE_CODE_FUNCTION: {
643       // FUNCTION: [vararg, retty, paramty x N]
644       if (Record.size() < 2)
645         return Error("Invalid FUNCTION type record");
646       SmallVector<Type*, 8> ArgTys;
647       for (unsigned i = 2, e = Record.size(); i != e; ++i) {
648         if (Type *T = getTypeByID(Record[i]))
649           ArgTys.push_back(T);
650         else
651           break;
652       }
653 
654       ResultTy = getTypeByID(Record[1]);
655       if (ResultTy == 0 || ArgTys.size() < Record.size()-2)
656         return Error("invalid type in function type");
657 
658       ResultTy = FunctionType::get(ResultTy, ArgTys, Record[0]);
659       break;
660     }
661     case bitc::TYPE_CODE_STRUCT_ANON: {  // STRUCT: [ispacked, eltty x N]
662       if (Record.size() < 1)
663         return Error("Invalid STRUCT type record");
664       SmallVector<Type*, 8> EltTys;
665       for (unsigned i = 1, e = Record.size(); i != e; ++i) {
666         if (Type *T = getTypeByID(Record[i]))
667           EltTys.push_back(T);
668         else
669           break;
670       }
671       if (EltTys.size() != Record.size()-1)
672         return Error("invalid type in struct type");
673       ResultTy = StructType::get(Context, EltTys, Record[0]);
674       break;
675     }
676     case bitc::TYPE_CODE_STRUCT_NAME:   // STRUCT_NAME: [strchr x N]
677       if (ConvertToString(Record, 0, TypeName))
678         return Error("Invalid STRUCT_NAME record");
679       continue;
680 
681     case bitc::TYPE_CODE_STRUCT_NAMED: { // STRUCT: [ispacked, eltty x N]
682       if (Record.size() < 1)
683         return Error("Invalid STRUCT type record");
684 
685       if (NumRecords >= TypeList.size())
686         return Error("invalid TYPE table");
687 
688       // Check to see if this was forward referenced, if so fill in the temp.
689       StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
690       if (Res) {
691         Res->setName(TypeName);
692         TypeList[NumRecords] = 0;
693       } else  // Otherwise, create a new struct.
694         Res = StructType::create(Context, TypeName);
695       TypeName.clear();
696 
697       SmallVector<Type*, 8> EltTys;
698       for (unsigned i = 1, e = Record.size(); i != e; ++i) {
699         if (Type *T = getTypeByID(Record[i]))
700           EltTys.push_back(T);
701         else
702           break;
703       }
704       if (EltTys.size() != Record.size()-1)
705         return Error("invalid STRUCT type record");
706       Res->setBody(EltTys, Record[0]);
707       ResultTy = Res;
708       break;
709     }
710     case bitc::TYPE_CODE_OPAQUE: {       // OPAQUE: []
711       if (Record.size() != 1)
712         return Error("Invalid OPAQUE type record");
713 
714       if (NumRecords >= TypeList.size())
715         return Error("invalid TYPE table");
716 
717       // Check to see if this was forward referenced, if so fill in the temp.
718       StructType *Res = cast_or_null<StructType>(TypeList[NumRecords]);
719       if (Res) {
720         Res->setName(TypeName);
721         TypeList[NumRecords] = 0;
722       } else  // Otherwise, create a new struct with no body.
723         Res = StructType::create(Context, TypeName);
724       TypeName.clear();
725       ResultTy = Res;
726       break;
727     }
728     case bitc::TYPE_CODE_ARRAY:     // ARRAY: [numelts, eltty]
729       if (Record.size() < 2)
730         return Error("Invalid ARRAY type record");
731       if ((ResultTy = getTypeByID(Record[1])))
732         ResultTy = ArrayType::get(ResultTy, Record[0]);
733       else
734         return Error("Invalid ARRAY type element");
735       break;
736     case bitc::TYPE_CODE_VECTOR:    // VECTOR: [numelts, eltty]
737       if (Record.size() < 2)
738         return Error("Invalid VECTOR type record");
739       if ((ResultTy = getTypeByID(Record[1])))
740         ResultTy = VectorType::get(ResultTy, Record[0]);
741       else
742         return Error("Invalid ARRAY type element");
743       break;
744     }
745 
746     if (NumRecords >= TypeList.size())
747       return Error("invalid TYPE table");
748     assert(ResultTy && "Didn't read a type?");
749     assert(TypeList[NumRecords] == 0 && "Already read type?");
750     TypeList[NumRecords++] = ResultTy;
751   }
752 }
753 
754 bool BitcodeReader::ParseValueSymbolTable() {
755   if (Stream.EnterSubBlock(bitc::VALUE_SYMTAB_BLOCK_ID))
756     return Error("Malformed block record");
757 
758   SmallVector<uint64_t, 64> Record;
759 
760   // Read all the records for this value table.
761   SmallString<128> ValueName;
762   while (1) {
763     unsigned Code = Stream.ReadCode();
764     if (Code == bitc::END_BLOCK) {
765       if (Stream.ReadBlockEnd())
766         return Error("Error at end of value symbol table block");
767       return false;
768     }
769     if (Code == bitc::ENTER_SUBBLOCK) {
770       // No known subblocks, always skip them.
771       Stream.ReadSubBlockID();
772       if (Stream.SkipBlock())
773         return Error("Malformed block record");
774       continue;
775     }
776 
777     if (Code == bitc::DEFINE_ABBREV) {
778       Stream.ReadAbbrevRecord();
779       continue;
780     }
781 
782     // Read a record.
783     Record.clear();
784     switch (Stream.ReadRecord(Code, Record)) {
785     default:  // Default behavior: unknown type.
786       break;
787     case bitc::VST_CODE_ENTRY: {  // VST_ENTRY: [valueid, namechar x N]
788       if (ConvertToString(Record, 1, ValueName))
789         return Error("Invalid VST_ENTRY record");
790       unsigned ValueID = Record[0];
791       if (ValueID >= ValueList.size())
792         return Error("Invalid Value ID in VST_ENTRY record");
793       Value *V = ValueList[ValueID];
794 
795       V->setName(StringRef(ValueName.data(), ValueName.size()));
796       ValueName.clear();
797       break;
798     }
799     case bitc::VST_CODE_BBENTRY: {
800       if (ConvertToString(Record, 1, ValueName))
801         return Error("Invalid VST_BBENTRY record");
802       BasicBlock *BB = getBasicBlock(Record[0]);
803       if (BB == 0)
804         return Error("Invalid BB ID in VST_BBENTRY record");
805 
806       BB->setName(StringRef(ValueName.data(), ValueName.size()));
807       ValueName.clear();
808       break;
809     }
810     }
811   }
812 }
813 
814 bool BitcodeReader::ParseMetadata() {
815   unsigned NextMDValueNo = MDValueList.size();
816 
817   if (Stream.EnterSubBlock(bitc::METADATA_BLOCK_ID))
818     return Error("Malformed block record");
819 
820   SmallVector<uint64_t, 64> Record;
821 
822   // Read all the records.
823   while (1) {
824     unsigned Code = Stream.ReadCode();
825     if (Code == bitc::END_BLOCK) {
826       if (Stream.ReadBlockEnd())
827         return Error("Error at end of PARAMATTR block");
828       return false;
829     }
830 
831     if (Code == bitc::ENTER_SUBBLOCK) {
832       // No known subblocks, always skip them.
833       Stream.ReadSubBlockID();
834       if (Stream.SkipBlock())
835         return Error("Malformed block record");
836       continue;
837     }
838 
839     if (Code == bitc::DEFINE_ABBREV) {
840       Stream.ReadAbbrevRecord();
841       continue;
842     }
843 
844     bool IsFunctionLocal = false;
845     // Read a record.
846     Record.clear();
847     Code = Stream.ReadRecord(Code, Record);
848     switch (Code) {
849     default:  // Default behavior: ignore.
850       break;
851     case bitc::METADATA_NAME: {
852       // Read named of the named metadata.
853       unsigned NameLength = Record.size();
854       SmallString<8> Name;
855       Name.resize(NameLength);
856       for (unsigned i = 0; i != NameLength; ++i)
857         Name[i] = Record[i];
858       Record.clear();
859       Code = Stream.ReadCode();
860 
861       // METADATA_NAME is always followed by METADATA_NAMED_NODE.
862       unsigned NextBitCode = Stream.ReadRecord(Code, Record);
863       assert(NextBitCode == bitc::METADATA_NAMED_NODE); (void)NextBitCode;
864 
865       // Read named metadata elements.
866       unsigned Size = Record.size();
867       NamedMDNode *NMD = TheModule->getOrInsertNamedMetadata(Name);
868       for (unsigned i = 0; i != Size; ++i) {
869         MDNode *MD = dyn_cast<MDNode>(MDValueList.getValueFwdRef(Record[i]));
870         if (MD == 0)
871           return Error("Malformed metadata record");
872         NMD->addOperand(MD);
873       }
874       break;
875     }
876     case bitc::METADATA_FN_NODE:
877       IsFunctionLocal = true;
878       // fall-through
879     case bitc::METADATA_NODE: {
880       if (Record.size() % 2 == 1)
881         return Error("Invalid METADATA_NODE record");
882 
883       unsigned Size = Record.size();
884       SmallVector<Value*, 8> Elts;
885       for (unsigned i = 0; i != Size; i += 2) {
886         Type *Ty = getTypeByID(Record[i]);
887         if (!Ty) return Error("Invalid METADATA_NODE record");
888         if (Ty->isMetadataTy())
889           Elts.push_back(MDValueList.getValueFwdRef(Record[i+1]));
890         else if (!Ty->isVoidTy())
891           Elts.push_back(ValueList.getValueFwdRef(Record[i+1], Ty));
892         else
893           Elts.push_back(NULL);
894       }
895       Value *V = MDNode::getWhenValsUnresolved(Context, Elts, IsFunctionLocal);
896       IsFunctionLocal = false;
897       MDValueList.AssignValue(V, NextMDValueNo++);
898       break;
899     }
900     case bitc::METADATA_STRING: {
901       unsigned MDStringLength = Record.size();
902       SmallString<8> String;
903       String.resize(MDStringLength);
904       for (unsigned i = 0; i != MDStringLength; ++i)
905         String[i] = Record[i];
906       Value *V = MDString::get(Context,
907                                StringRef(String.data(), String.size()));
908       MDValueList.AssignValue(V, NextMDValueNo++);
909       break;
910     }
911     case bitc::METADATA_KIND: {
912       unsigned RecordLength = Record.size();
913       if (Record.empty() || RecordLength < 2)
914         return Error("Invalid METADATA_KIND record");
915       SmallString<8> Name;
916       Name.resize(RecordLength-1);
917       unsigned Kind = Record[0];
918       for (unsigned i = 1; i != RecordLength; ++i)
919         Name[i-1] = Record[i];
920 
921       unsigned NewKind = TheModule->getMDKindID(Name.str());
922       if (!MDKindMap.insert(std::make_pair(Kind, NewKind)).second)
923         return Error("Conflicting METADATA_KIND records");
924       break;
925     }
926     }
927   }
928 }
929 
930 /// DecodeSignRotatedValue - Decode a signed value stored with the sign bit in
931 /// the LSB for dense VBR encoding.
932 static uint64_t DecodeSignRotatedValue(uint64_t V) {
933   if ((V & 1) == 0)
934     return V >> 1;
935   if (V != 1)
936     return -(V >> 1);
937   // There is no such thing as -0 with integers.  "-0" really means MININT.
938   return 1ULL << 63;
939 }
940 
941 /// ResolveGlobalAndAliasInits - Resolve all of the initializers for global
942 /// values and aliases that we can.
943 bool BitcodeReader::ResolveGlobalAndAliasInits() {
944   std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInitWorklist;
945   std::vector<std::pair<GlobalAlias*, unsigned> > AliasInitWorklist;
946 
947   GlobalInitWorklist.swap(GlobalInits);
948   AliasInitWorklist.swap(AliasInits);
949 
950   while (!GlobalInitWorklist.empty()) {
951     unsigned ValID = GlobalInitWorklist.back().second;
952     if (ValID >= ValueList.size()) {
953       // Not ready to resolve this yet, it requires something later in the file.
954       GlobalInits.push_back(GlobalInitWorklist.back());
955     } else {
956       if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
957         GlobalInitWorklist.back().first->setInitializer(C);
958       else
959         return Error("Global variable initializer is not a constant!");
960     }
961     GlobalInitWorklist.pop_back();
962   }
963 
964   while (!AliasInitWorklist.empty()) {
965     unsigned ValID = AliasInitWorklist.back().second;
966     if (ValID >= ValueList.size()) {
967       AliasInits.push_back(AliasInitWorklist.back());
968     } else {
969       if (Constant *C = dyn_cast<Constant>(ValueList[ValID]))
970         AliasInitWorklist.back().first->setAliasee(C);
971       else
972         return Error("Alias initializer is not a constant!");
973     }
974     AliasInitWorklist.pop_back();
975   }
976   return false;
977 }
978 
979 bool BitcodeReader::ParseConstants() {
980   if (Stream.EnterSubBlock(bitc::CONSTANTS_BLOCK_ID))
981     return Error("Malformed block record");
982 
983   SmallVector<uint64_t, 64> Record;
984 
985   // Read all the records for this value table.
986   Type *CurTy = Type::getInt32Ty(Context);
987   unsigned NextCstNo = ValueList.size();
988   while (1) {
989     unsigned Code = Stream.ReadCode();
990     if (Code == bitc::END_BLOCK)
991       break;
992 
993     if (Code == bitc::ENTER_SUBBLOCK) {
994       // No known subblocks, always skip them.
995       Stream.ReadSubBlockID();
996       if (Stream.SkipBlock())
997         return Error("Malformed block record");
998       continue;
999     }
1000 
1001     if (Code == bitc::DEFINE_ABBREV) {
1002       Stream.ReadAbbrevRecord();
1003       continue;
1004     }
1005 
1006     // Read a record.
1007     Record.clear();
1008     Value *V = 0;
1009     unsigned BitCode = Stream.ReadRecord(Code, Record);
1010     switch (BitCode) {
1011     default:  // Default behavior: unknown constant
1012     case bitc::CST_CODE_UNDEF:     // UNDEF
1013       V = UndefValue::get(CurTy);
1014       break;
1015     case bitc::CST_CODE_SETTYPE:   // SETTYPE: [typeid]
1016       if (Record.empty())
1017         return Error("Malformed CST_SETTYPE record");
1018       if (Record[0] >= TypeList.size())
1019         return Error("Invalid Type ID in CST_SETTYPE record");
1020       CurTy = TypeList[Record[0]];
1021       continue;  // Skip the ValueList manipulation.
1022     case bitc::CST_CODE_NULL:      // NULL
1023       V = Constant::getNullValue(CurTy);
1024       break;
1025     case bitc::CST_CODE_INTEGER:   // INTEGER: [intval]
1026       if (!CurTy->isIntegerTy() || Record.empty())
1027         return Error("Invalid CST_INTEGER record");
1028       V = ConstantInt::get(CurTy, DecodeSignRotatedValue(Record[0]));
1029       break;
1030     case bitc::CST_CODE_WIDE_INTEGER: {// WIDE_INTEGER: [n x intval]
1031       if (!CurTy->isIntegerTy() || Record.empty())
1032         return Error("Invalid WIDE_INTEGER record");
1033 
1034       unsigned NumWords = Record.size();
1035       SmallVector<uint64_t, 8> Words;
1036       Words.resize(NumWords);
1037       for (unsigned i = 0; i != NumWords; ++i)
1038         Words[i] = DecodeSignRotatedValue(Record[i]);
1039       V = ConstantInt::get(Context,
1040                            APInt(cast<IntegerType>(CurTy)->getBitWidth(),
1041                                  Words));
1042       break;
1043     }
1044     case bitc::CST_CODE_FLOAT: {    // FLOAT: [fpval]
1045       if (Record.empty())
1046         return Error("Invalid FLOAT record");
1047       if (CurTy->isHalfTy())
1048         V = ConstantFP::get(Context, APFloat(APInt(16, (uint16_t)Record[0])));
1049       else if (CurTy->isFloatTy())
1050         V = ConstantFP::get(Context, APFloat(APInt(32, (uint32_t)Record[0])));
1051       else if (CurTy->isDoubleTy())
1052         V = ConstantFP::get(Context, APFloat(APInt(64, Record[0])));
1053       else if (CurTy->isX86_FP80Ty()) {
1054         // Bits are not stored the same way as a normal i80 APInt, compensate.
1055         uint64_t Rearrange[2];
1056         Rearrange[0] = (Record[1] & 0xffffLL) | (Record[0] << 16);
1057         Rearrange[1] = Record[0] >> 48;
1058         V = ConstantFP::get(Context, APFloat(APInt(80, Rearrange)));
1059       } else if (CurTy->isFP128Ty())
1060         V = ConstantFP::get(Context, APFloat(APInt(128, Record), true));
1061       else if (CurTy->isPPC_FP128Ty())
1062         V = ConstantFP::get(Context, APFloat(APInt(128, Record)));
1063       else
1064         V = UndefValue::get(CurTy);
1065       break;
1066     }
1067 
1068     case bitc::CST_CODE_AGGREGATE: {// AGGREGATE: [n x value number]
1069       if (Record.empty())
1070         return Error("Invalid CST_AGGREGATE record");
1071 
1072       unsigned Size = Record.size();
1073       SmallVector<Constant*, 16> Elts;
1074 
1075       if (StructType *STy = dyn_cast<StructType>(CurTy)) {
1076         for (unsigned i = 0; i != Size; ++i)
1077           Elts.push_back(ValueList.getConstantFwdRef(Record[i],
1078                                                      STy->getElementType(i)));
1079         V = ConstantStruct::get(STy, Elts);
1080       } else if (ArrayType *ATy = dyn_cast<ArrayType>(CurTy)) {
1081         Type *EltTy = ATy->getElementType();
1082         for (unsigned i = 0; i != Size; ++i)
1083           Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1084         V = ConstantArray::get(ATy, Elts);
1085       } else if (VectorType *VTy = dyn_cast<VectorType>(CurTy)) {
1086         Type *EltTy = VTy->getElementType();
1087         for (unsigned i = 0; i != Size; ++i)
1088           Elts.push_back(ValueList.getConstantFwdRef(Record[i], EltTy));
1089         V = ConstantVector::get(Elts);
1090       } else {
1091         V = UndefValue::get(CurTy);
1092       }
1093       break;
1094     }
1095     case bitc::CST_CODE_STRING: { // STRING: [values]
1096       if (Record.empty())
1097         return Error("Invalid CST_AGGREGATE record");
1098 
1099       ArrayType *ATy = cast<ArrayType>(CurTy);
1100       Type *EltTy = ATy->getElementType();
1101 
1102       unsigned Size = Record.size();
1103       SmallVector<Constant*, 16> Elts;
1104       for (unsigned i = 0; i != Size; ++i)
1105         Elts.push_back(ConstantInt::get(EltTy, Record[i]));
1106       V = ConstantArray::get(ATy, Elts);
1107       break;
1108     }
1109     case bitc::CST_CODE_CSTRING: { // CSTRING: [values]
1110       if (Record.empty())
1111         return Error("Invalid CST_AGGREGATE record");
1112 
1113       ArrayType *ATy = cast<ArrayType>(CurTy);
1114       Type *EltTy = ATy->getElementType();
1115 
1116       unsigned Size = Record.size();
1117       SmallVector<Constant*, 16> Elts;
1118       for (unsigned i = 0; i != Size; ++i)
1119         Elts.push_back(ConstantInt::get(EltTy, Record[i]));
1120       Elts.push_back(Constant::getNullValue(EltTy));
1121       V = ConstantArray::get(ATy, Elts);
1122       break;
1123     }
1124     case bitc::CST_CODE_CE_BINOP: {  // CE_BINOP: [opcode, opval, opval]
1125       if (Record.size() < 3) return Error("Invalid CE_BINOP record");
1126       int Opc = GetDecodedBinaryOpcode(Record[0], CurTy);
1127       if (Opc < 0) {
1128         V = UndefValue::get(CurTy);  // Unknown binop.
1129       } else {
1130         Constant *LHS = ValueList.getConstantFwdRef(Record[1], CurTy);
1131         Constant *RHS = ValueList.getConstantFwdRef(Record[2], CurTy);
1132         unsigned Flags = 0;
1133         if (Record.size() >= 4) {
1134           if (Opc == Instruction::Add ||
1135               Opc == Instruction::Sub ||
1136               Opc == Instruction::Mul ||
1137               Opc == Instruction::Shl) {
1138             if (Record[3] & (1 << bitc::OBO_NO_SIGNED_WRAP))
1139               Flags |= OverflowingBinaryOperator::NoSignedWrap;
1140             if (Record[3] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
1141               Flags |= OverflowingBinaryOperator::NoUnsignedWrap;
1142           } else if (Opc == Instruction::SDiv ||
1143                      Opc == Instruction::UDiv ||
1144                      Opc == Instruction::LShr ||
1145                      Opc == Instruction::AShr) {
1146             if (Record[3] & (1 << bitc::PEO_EXACT))
1147               Flags |= SDivOperator::IsExact;
1148           }
1149         }
1150         V = ConstantExpr::get(Opc, LHS, RHS, Flags);
1151       }
1152       break;
1153     }
1154     case bitc::CST_CODE_CE_CAST: {  // CE_CAST: [opcode, opty, opval]
1155       if (Record.size() < 3) return Error("Invalid CE_CAST record");
1156       int Opc = GetDecodedCastOpcode(Record[0]);
1157       if (Opc < 0) {
1158         V = UndefValue::get(CurTy);  // Unknown cast.
1159       } else {
1160         Type *OpTy = getTypeByID(Record[1]);
1161         if (!OpTy) return Error("Invalid CE_CAST record");
1162         Constant *Op = ValueList.getConstantFwdRef(Record[2], OpTy);
1163         V = ConstantExpr::getCast(Opc, Op, CurTy);
1164       }
1165       break;
1166     }
1167     case bitc::CST_CODE_CE_INBOUNDS_GEP:
1168     case bitc::CST_CODE_CE_GEP: {  // CE_GEP:        [n x operands]
1169       if (Record.size() & 1) return Error("Invalid CE_GEP record");
1170       SmallVector<Constant*, 16> Elts;
1171       for (unsigned i = 0, e = Record.size(); i != e; i += 2) {
1172         Type *ElTy = getTypeByID(Record[i]);
1173         if (!ElTy) return Error("Invalid CE_GEP record");
1174         Elts.push_back(ValueList.getConstantFwdRef(Record[i+1], ElTy));
1175       }
1176       ArrayRef<Constant *> Indices(Elts.begin() + 1, Elts.end());
1177       V = ConstantExpr::getGetElementPtr(Elts[0], Indices,
1178                                          BitCode ==
1179                                            bitc::CST_CODE_CE_INBOUNDS_GEP);
1180       break;
1181     }
1182     case bitc::CST_CODE_CE_SELECT:  // CE_SELECT: [opval#, opval#, opval#]
1183       if (Record.size() < 3) return Error("Invalid CE_SELECT record");
1184       V = ConstantExpr::getSelect(ValueList.getConstantFwdRef(Record[0],
1185                                                               Type::getInt1Ty(Context)),
1186                                   ValueList.getConstantFwdRef(Record[1],CurTy),
1187                                   ValueList.getConstantFwdRef(Record[2],CurTy));
1188       break;
1189     case bitc::CST_CODE_CE_EXTRACTELT: { // CE_EXTRACTELT: [opty, opval, opval]
1190       if (Record.size() < 3) return Error("Invalid CE_EXTRACTELT record");
1191       VectorType *OpTy =
1192         dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1193       if (OpTy == 0) return Error("Invalid CE_EXTRACTELT record");
1194       Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1195       Constant *Op1 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
1196       V = ConstantExpr::getExtractElement(Op0, Op1);
1197       break;
1198     }
1199     case bitc::CST_CODE_CE_INSERTELT: { // CE_INSERTELT: [opval, opval, opval]
1200       VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1201       if (Record.size() < 3 || OpTy == 0)
1202         return Error("Invalid CE_INSERTELT record");
1203       Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1204       Constant *Op1 = ValueList.getConstantFwdRef(Record[1],
1205                                                   OpTy->getElementType());
1206       Constant *Op2 = ValueList.getConstantFwdRef(Record[2], Type::getInt32Ty(Context));
1207       V = ConstantExpr::getInsertElement(Op0, Op1, Op2);
1208       break;
1209     }
1210     case bitc::CST_CODE_CE_SHUFFLEVEC: { // CE_SHUFFLEVEC: [opval, opval, opval]
1211       VectorType *OpTy = dyn_cast<VectorType>(CurTy);
1212       if (Record.size() < 3 || OpTy == 0)
1213         return Error("Invalid CE_SHUFFLEVEC record");
1214       Constant *Op0 = ValueList.getConstantFwdRef(Record[0], OpTy);
1215       Constant *Op1 = ValueList.getConstantFwdRef(Record[1], OpTy);
1216       Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
1217                                                  OpTy->getNumElements());
1218       Constant *Op2 = ValueList.getConstantFwdRef(Record[2], ShufTy);
1219       V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1220       break;
1221     }
1222     case bitc::CST_CODE_CE_SHUFVEC_EX: { // [opty, opval, opval, opval]
1223       VectorType *RTy = dyn_cast<VectorType>(CurTy);
1224       VectorType *OpTy =
1225         dyn_cast_or_null<VectorType>(getTypeByID(Record[0]));
1226       if (Record.size() < 4 || RTy == 0 || OpTy == 0)
1227         return Error("Invalid CE_SHUFVEC_EX record");
1228       Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1229       Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1230       Type *ShufTy = VectorType::get(Type::getInt32Ty(Context),
1231                                                  RTy->getNumElements());
1232       Constant *Op2 = ValueList.getConstantFwdRef(Record[3], ShufTy);
1233       V = ConstantExpr::getShuffleVector(Op0, Op1, Op2);
1234       break;
1235     }
1236     case bitc::CST_CODE_CE_CMP: {     // CE_CMP: [opty, opval, opval, pred]
1237       if (Record.size() < 4) return Error("Invalid CE_CMP record");
1238       Type *OpTy = getTypeByID(Record[0]);
1239       if (OpTy == 0) return Error("Invalid CE_CMP record");
1240       Constant *Op0 = ValueList.getConstantFwdRef(Record[1], OpTy);
1241       Constant *Op1 = ValueList.getConstantFwdRef(Record[2], OpTy);
1242 
1243       if (OpTy->isFPOrFPVectorTy())
1244         V = ConstantExpr::getFCmp(Record[3], Op0, Op1);
1245       else
1246         V = ConstantExpr::getICmp(Record[3], Op0, Op1);
1247       break;
1248     }
1249     case bitc::CST_CODE_INLINEASM: {
1250       if (Record.size() < 2) return Error("Invalid INLINEASM record");
1251       std::string AsmStr, ConstrStr;
1252       bool HasSideEffects = Record[0] & 1;
1253       bool IsAlignStack = Record[0] >> 1;
1254       unsigned AsmStrSize = Record[1];
1255       if (2+AsmStrSize >= Record.size())
1256         return Error("Invalid INLINEASM record");
1257       unsigned ConstStrSize = Record[2+AsmStrSize];
1258       if (3+AsmStrSize+ConstStrSize > Record.size())
1259         return Error("Invalid INLINEASM record");
1260 
1261       for (unsigned i = 0; i != AsmStrSize; ++i)
1262         AsmStr += (char)Record[2+i];
1263       for (unsigned i = 0; i != ConstStrSize; ++i)
1264         ConstrStr += (char)Record[3+AsmStrSize+i];
1265       PointerType *PTy = cast<PointerType>(CurTy);
1266       V = InlineAsm::get(cast<FunctionType>(PTy->getElementType()),
1267                          AsmStr, ConstrStr, HasSideEffects, IsAlignStack);
1268       break;
1269     }
1270     case bitc::CST_CODE_BLOCKADDRESS:{
1271       if (Record.size() < 3) return Error("Invalid CE_BLOCKADDRESS record");
1272       Type *FnTy = getTypeByID(Record[0]);
1273       if (FnTy == 0) return Error("Invalid CE_BLOCKADDRESS record");
1274       Function *Fn =
1275         dyn_cast_or_null<Function>(ValueList.getConstantFwdRef(Record[1],FnTy));
1276       if (Fn == 0) return Error("Invalid CE_BLOCKADDRESS record");
1277 
1278       GlobalVariable *FwdRef = new GlobalVariable(*Fn->getParent(),
1279                                                   Type::getInt8Ty(Context),
1280                                             false, GlobalValue::InternalLinkage,
1281                                                   0, "");
1282       BlockAddrFwdRefs[Fn].push_back(std::make_pair(Record[2], FwdRef));
1283       V = FwdRef;
1284       break;
1285     }
1286     }
1287 
1288     ValueList.AssignValue(V, NextCstNo);
1289     ++NextCstNo;
1290   }
1291 
1292   if (NextCstNo != ValueList.size())
1293     return Error("Invalid constant reference!");
1294 
1295   if (Stream.ReadBlockEnd())
1296     return Error("Error at end of constants block");
1297 
1298   // Once all the constants have been read, go through and resolve forward
1299   // references.
1300   ValueList.ResolveConstantForwardRefs();
1301   return false;
1302 }
1303 
1304 bool BitcodeReader::ParseUseLists() {
1305   if (Stream.EnterSubBlock(bitc::USELIST_BLOCK_ID))
1306     return Error("Malformed block record");
1307 
1308   SmallVector<uint64_t, 64> Record;
1309 
1310   // Read all the records.
1311   while (1) {
1312     unsigned Code = Stream.ReadCode();
1313     if (Code == bitc::END_BLOCK) {
1314       if (Stream.ReadBlockEnd())
1315         return Error("Error at end of use-list table block");
1316       return false;
1317     }
1318 
1319     if (Code == bitc::ENTER_SUBBLOCK) {
1320       // No known subblocks, always skip them.
1321       Stream.ReadSubBlockID();
1322       if (Stream.SkipBlock())
1323         return Error("Malformed block record");
1324       continue;
1325     }
1326 
1327     if (Code == bitc::DEFINE_ABBREV) {
1328       Stream.ReadAbbrevRecord();
1329       continue;
1330     }
1331 
1332     // Read a use list record.
1333     Record.clear();
1334     switch (Stream.ReadRecord(Code, Record)) {
1335     default:  // Default behavior: unknown type.
1336       break;
1337     case bitc::USELIST_CODE_ENTRY: { // USELIST_CODE_ENTRY: TBD.
1338       unsigned RecordLength = Record.size();
1339       if (RecordLength < 1)
1340         return Error ("Invalid UseList reader!");
1341       UseListRecords.push_back(Record);
1342       break;
1343     }
1344     }
1345   }
1346 }
1347 
1348 /// RememberAndSkipFunctionBody - When we see the block for a function body,
1349 /// remember where it is and then skip it.  This lets us lazily deserialize the
1350 /// functions.
1351 bool BitcodeReader::RememberAndSkipFunctionBody() {
1352   // Get the function we are talking about.
1353   if (FunctionsWithBodies.empty())
1354     return Error("Insufficient function protos");
1355 
1356   Function *Fn = FunctionsWithBodies.back();
1357   FunctionsWithBodies.pop_back();
1358 
1359   // Save the current stream state.
1360   uint64_t CurBit = Stream.GetCurrentBitNo();
1361   DeferredFunctionInfo[Fn] = CurBit;
1362 
1363   // Skip over the function block for now.
1364   if (Stream.SkipBlock())
1365     return Error("Malformed block record");
1366   return false;
1367 }
1368 
1369 bool BitcodeReader::ParseModule() {
1370   if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
1371     return Error("Malformed block record");
1372 
1373   SmallVector<uint64_t, 64> Record;
1374   std::vector<std::string> SectionTable;
1375   std::vector<std::string> GCTable;
1376 
1377   // Read all the records for this module.
1378   while (!Stream.AtEndOfStream()) {
1379     unsigned Code = Stream.ReadCode();
1380     if (Code == bitc::END_BLOCK) {
1381       if (Stream.ReadBlockEnd())
1382         return Error("Error at end of module block");
1383 
1384       // Patch the initializers for globals and aliases up.
1385       ResolveGlobalAndAliasInits();
1386       if (!GlobalInits.empty() || !AliasInits.empty())
1387         return Error("Malformed global initializer set");
1388       if (!FunctionsWithBodies.empty())
1389         return Error("Too few function bodies found");
1390 
1391       // Look for intrinsic functions which need to be upgraded at some point
1392       for (Module::iterator FI = TheModule->begin(), FE = TheModule->end();
1393            FI != FE; ++FI) {
1394         Function* NewFn;
1395         if (UpgradeIntrinsicFunction(FI, NewFn))
1396           UpgradedIntrinsics.push_back(std::make_pair(FI, NewFn));
1397       }
1398 
1399       // Look for global variables which need to be renamed.
1400       for (Module::global_iterator
1401              GI = TheModule->global_begin(), GE = TheModule->global_end();
1402            GI != GE; ++GI)
1403         UpgradeGlobalVariable(GI);
1404 
1405       // Force deallocation of memory for these vectors to favor the client that
1406       // want lazy deserialization.
1407       std::vector<std::pair<GlobalVariable*, unsigned> >().swap(GlobalInits);
1408       std::vector<std::pair<GlobalAlias*, unsigned> >().swap(AliasInits);
1409       std::vector<Function*>().swap(FunctionsWithBodies);
1410       return false;
1411     }
1412 
1413     if (Code == bitc::ENTER_SUBBLOCK) {
1414       switch (Stream.ReadSubBlockID()) {
1415       default:  // Skip unknown content.
1416         if (Stream.SkipBlock())
1417           return Error("Malformed block record");
1418         break;
1419       case bitc::BLOCKINFO_BLOCK_ID:
1420         if (Stream.ReadBlockInfoBlock())
1421           return Error("Malformed BlockInfoBlock");
1422         break;
1423       case bitc::PARAMATTR_BLOCK_ID:
1424         if (ParseAttributeBlock())
1425           return true;
1426         break;
1427       case bitc::TYPE_BLOCK_ID_NEW:
1428         if (ParseTypeTable())
1429           return true;
1430         break;
1431       case bitc::VALUE_SYMTAB_BLOCK_ID:
1432         if (ParseValueSymbolTable())
1433           return true;
1434         break;
1435       case bitc::CONSTANTS_BLOCK_ID:
1436         if (ParseConstants() || ResolveGlobalAndAliasInits())
1437           return true;
1438         break;
1439       case bitc::METADATA_BLOCK_ID:
1440         if (ParseMetadata())
1441           return true;
1442         break;
1443       case bitc::FUNCTION_BLOCK_ID:
1444         // If this is the first function body we've seen, reverse the
1445         // FunctionsWithBodies list.
1446         if (!HasReversedFunctionsWithBodies) {
1447           std::reverse(FunctionsWithBodies.begin(), FunctionsWithBodies.end());
1448           HasReversedFunctionsWithBodies = true;
1449         }
1450 
1451         if (RememberAndSkipFunctionBody())
1452           return true;
1453         break;
1454       case bitc::USELIST_BLOCK_ID:
1455         if (ParseUseLists())
1456           return true;
1457         break;
1458       }
1459       continue;
1460     }
1461 
1462     if (Code == bitc::DEFINE_ABBREV) {
1463       Stream.ReadAbbrevRecord();
1464       continue;
1465     }
1466 
1467     // Read a record.
1468     switch (Stream.ReadRecord(Code, Record)) {
1469     default: break;  // Default behavior, ignore unknown content.
1470     case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
1471       if (Record.size() < 1)
1472         return Error("Malformed MODULE_CODE_VERSION");
1473       // Only version #0 is supported so far.
1474       if (Record[0] != 0)
1475         return Error("Unknown bitstream version!");
1476       break;
1477     case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1478       std::string S;
1479       if (ConvertToString(Record, 0, S))
1480         return Error("Invalid MODULE_CODE_TRIPLE record");
1481       TheModule->setTargetTriple(S);
1482       break;
1483     }
1484     case bitc::MODULE_CODE_DATALAYOUT: {  // DATALAYOUT: [strchr x N]
1485       std::string S;
1486       if (ConvertToString(Record, 0, S))
1487         return Error("Invalid MODULE_CODE_DATALAYOUT record");
1488       TheModule->setDataLayout(S);
1489       break;
1490     }
1491     case bitc::MODULE_CODE_ASM: {  // ASM: [strchr x N]
1492       std::string S;
1493       if (ConvertToString(Record, 0, S))
1494         return Error("Invalid MODULE_CODE_ASM record");
1495       TheModule->setModuleInlineAsm(S);
1496       break;
1497     }
1498     case bitc::MODULE_CODE_DEPLIB: {  // DEPLIB: [strchr x N]
1499       std::string S;
1500       if (ConvertToString(Record, 0, S))
1501         return Error("Invalid MODULE_CODE_DEPLIB record");
1502       TheModule->addLibrary(S);
1503       break;
1504     }
1505     case bitc::MODULE_CODE_SECTIONNAME: {  // SECTIONNAME: [strchr x N]
1506       std::string S;
1507       if (ConvertToString(Record, 0, S))
1508         return Error("Invalid MODULE_CODE_SECTIONNAME record");
1509       SectionTable.push_back(S);
1510       break;
1511     }
1512     case bitc::MODULE_CODE_GCNAME: {  // SECTIONNAME: [strchr x N]
1513       std::string S;
1514       if (ConvertToString(Record, 0, S))
1515         return Error("Invalid MODULE_CODE_GCNAME record");
1516       GCTable.push_back(S);
1517       break;
1518     }
1519     // GLOBALVAR: [pointer type, isconst, initid,
1520     //             linkage, alignment, section, visibility, threadlocal,
1521     //             unnamed_addr]
1522     case bitc::MODULE_CODE_GLOBALVAR: {
1523       if (Record.size() < 6)
1524         return Error("Invalid MODULE_CODE_GLOBALVAR record");
1525       Type *Ty = getTypeByID(Record[0]);
1526       if (!Ty) return Error("Invalid MODULE_CODE_GLOBALVAR record");
1527       if (!Ty->isPointerTy())
1528         return Error("Global not a pointer type!");
1529       unsigned AddressSpace = cast<PointerType>(Ty)->getAddressSpace();
1530       Ty = cast<PointerType>(Ty)->getElementType();
1531 
1532       bool isConstant = Record[1];
1533       GlobalValue::LinkageTypes Linkage = GetDecodedLinkage(Record[3]);
1534       unsigned Alignment = (1 << Record[4]) >> 1;
1535       std::string Section;
1536       if (Record[5]) {
1537         if (Record[5]-1 >= SectionTable.size())
1538           return Error("Invalid section ID");
1539         Section = SectionTable[Record[5]-1];
1540       }
1541       GlobalValue::VisibilityTypes Visibility = GlobalValue::DefaultVisibility;
1542       if (Record.size() > 6)
1543         Visibility = GetDecodedVisibility(Record[6]);
1544       bool isThreadLocal = false;
1545       if (Record.size() > 7)
1546         isThreadLocal = Record[7];
1547 
1548       bool UnnamedAddr = false;
1549       if (Record.size() > 8)
1550         UnnamedAddr = Record[8];
1551 
1552       GlobalVariable *NewGV =
1553         new GlobalVariable(*TheModule, Ty, isConstant, Linkage, 0, "", 0,
1554                            isThreadLocal, AddressSpace);
1555       NewGV->setAlignment(Alignment);
1556       if (!Section.empty())
1557         NewGV->setSection(Section);
1558       NewGV->setVisibility(Visibility);
1559       NewGV->setThreadLocal(isThreadLocal);
1560       NewGV->setUnnamedAddr(UnnamedAddr);
1561 
1562       ValueList.push_back(NewGV);
1563 
1564       // Remember which value to use for the global initializer.
1565       if (unsigned InitID = Record[2])
1566         GlobalInits.push_back(std::make_pair(NewGV, InitID-1));
1567       break;
1568     }
1569     // FUNCTION:  [type, callingconv, isproto, linkage, paramattr,
1570     //             alignment, section, visibility, gc, unnamed_addr]
1571     case bitc::MODULE_CODE_FUNCTION: {
1572       if (Record.size() < 8)
1573         return Error("Invalid MODULE_CODE_FUNCTION record");
1574       Type *Ty = getTypeByID(Record[0]);
1575       if (!Ty) return Error("Invalid MODULE_CODE_FUNCTION record");
1576       if (!Ty->isPointerTy())
1577         return Error("Function not a pointer type!");
1578       FunctionType *FTy =
1579         dyn_cast<FunctionType>(cast<PointerType>(Ty)->getElementType());
1580       if (!FTy)
1581         return Error("Function not a pointer to function type!");
1582 
1583       Function *Func = Function::Create(FTy, GlobalValue::ExternalLinkage,
1584                                         "", TheModule);
1585 
1586       Func->setCallingConv(static_cast<CallingConv::ID>(Record[1]));
1587       bool isProto = Record[2];
1588       Func->setLinkage(GetDecodedLinkage(Record[3]));
1589       Func->setAttributes(getAttributes(Record[4]));
1590 
1591       Func->setAlignment((1 << Record[5]) >> 1);
1592       if (Record[6]) {
1593         if (Record[6]-1 >= SectionTable.size())
1594           return Error("Invalid section ID");
1595         Func->setSection(SectionTable[Record[6]-1]);
1596       }
1597       Func->setVisibility(GetDecodedVisibility(Record[7]));
1598       if (Record.size() > 8 && Record[8]) {
1599         if (Record[8]-1 > GCTable.size())
1600           return Error("Invalid GC ID");
1601         Func->setGC(GCTable[Record[8]-1].c_str());
1602       }
1603       bool UnnamedAddr = false;
1604       if (Record.size() > 9)
1605         UnnamedAddr = Record[9];
1606       Func->setUnnamedAddr(UnnamedAddr);
1607       ValueList.push_back(Func);
1608 
1609       // If this is a function with a body, remember the prototype we are
1610       // creating now, so that we can match up the body with them later.
1611       if (!isProto)
1612         FunctionsWithBodies.push_back(Func);
1613       break;
1614     }
1615     // ALIAS: [alias type, aliasee val#, linkage]
1616     // ALIAS: [alias type, aliasee val#, linkage, visibility]
1617     case bitc::MODULE_CODE_ALIAS: {
1618       if (Record.size() < 3)
1619         return Error("Invalid MODULE_ALIAS record");
1620       Type *Ty = getTypeByID(Record[0]);
1621       if (!Ty) return Error("Invalid MODULE_ALIAS record");
1622       if (!Ty->isPointerTy())
1623         return Error("Function not a pointer type!");
1624 
1625       GlobalAlias *NewGA = new GlobalAlias(Ty, GetDecodedLinkage(Record[2]),
1626                                            "", 0, TheModule);
1627       // Old bitcode files didn't have visibility field.
1628       if (Record.size() > 3)
1629         NewGA->setVisibility(GetDecodedVisibility(Record[3]));
1630       ValueList.push_back(NewGA);
1631       AliasInits.push_back(std::make_pair(NewGA, Record[1]));
1632       break;
1633     }
1634     /// MODULE_CODE_PURGEVALS: [numvals]
1635     case bitc::MODULE_CODE_PURGEVALS:
1636       // Trim down the value list to the specified size.
1637       if (Record.size() < 1 || Record[0] > ValueList.size())
1638         return Error("Invalid MODULE_PURGEVALS record");
1639       ValueList.shrinkTo(Record[0]);
1640       break;
1641     }
1642     Record.clear();
1643   }
1644 
1645   return Error("Premature end of bitstream");
1646 }
1647 
1648 bool BitcodeReader::ParseBitcodeInto(Module *M) {
1649   TheModule = 0;
1650 
1651   unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1652   unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
1653 
1654   if (Buffer->getBufferSize() & 3) {
1655     if (!isRawBitcode(BufPtr, BufEnd) && !isBitcodeWrapper(BufPtr, BufEnd))
1656       return Error("Invalid bitcode signature");
1657     else
1658       return Error("Bitcode stream should be a multiple of 4 bytes in length");
1659   }
1660 
1661   // If we have a wrapper header, parse it and ignore the non-bc file contents.
1662   // The magic number is 0x0B17C0DE stored in little endian.
1663   if (isBitcodeWrapper(BufPtr, BufEnd))
1664     if (SkipBitcodeWrapperHeader(BufPtr, BufEnd))
1665       return Error("Invalid bitcode wrapper header");
1666 
1667   StreamFile.init(BufPtr, BufEnd);
1668   Stream.init(StreamFile);
1669 
1670   // Sniff for the signature.
1671   if (Stream.Read(8) != 'B' ||
1672       Stream.Read(8) != 'C' ||
1673       Stream.Read(4) != 0x0 ||
1674       Stream.Read(4) != 0xC ||
1675       Stream.Read(4) != 0xE ||
1676       Stream.Read(4) != 0xD)
1677     return Error("Invalid bitcode signature");
1678 
1679   // We expect a number of well-defined blocks, though we don't necessarily
1680   // need to understand them all.
1681   while (!Stream.AtEndOfStream()) {
1682     unsigned Code = Stream.ReadCode();
1683 
1684     if (Code != bitc::ENTER_SUBBLOCK) {
1685 
1686       // The ranlib in xcode 4 will align archive members by appending newlines
1687       // to the end of them. If this file size is a multiple of 4 but not 8, we
1688       // have to read and ignore these final 4 bytes :-(
1689       if (Stream.GetAbbrevIDWidth() == 2 && Code == 2 &&
1690           Stream.Read(6) == 2 && Stream.Read(24) == 0xa0a0a &&
1691 	  Stream.AtEndOfStream())
1692         return false;
1693 
1694       return Error("Invalid record at top-level");
1695     }
1696 
1697     unsigned BlockID = Stream.ReadSubBlockID();
1698 
1699     // We only know the MODULE subblock ID.
1700     switch (BlockID) {
1701     case bitc::BLOCKINFO_BLOCK_ID:
1702       if (Stream.ReadBlockInfoBlock())
1703         return Error("Malformed BlockInfoBlock");
1704       break;
1705     case bitc::MODULE_BLOCK_ID:
1706       // Reject multiple MODULE_BLOCK's in a single bitstream.
1707       if (TheModule)
1708         return Error("Multiple MODULE_BLOCKs in same stream");
1709       TheModule = M;
1710       if (ParseModule())
1711         return true;
1712       break;
1713     default:
1714       if (Stream.SkipBlock())
1715         return Error("Malformed block record");
1716       break;
1717     }
1718   }
1719 
1720   return false;
1721 }
1722 
1723 bool BitcodeReader::ParseModuleTriple(std::string &Triple) {
1724   if (Stream.EnterSubBlock(bitc::MODULE_BLOCK_ID))
1725     return Error("Malformed block record");
1726 
1727   SmallVector<uint64_t, 64> Record;
1728 
1729   // Read all the records for this module.
1730   while (!Stream.AtEndOfStream()) {
1731     unsigned Code = Stream.ReadCode();
1732     if (Code == bitc::END_BLOCK) {
1733       if (Stream.ReadBlockEnd())
1734         return Error("Error at end of module block");
1735 
1736       return false;
1737     }
1738 
1739     if (Code == bitc::ENTER_SUBBLOCK) {
1740       switch (Stream.ReadSubBlockID()) {
1741       default:  // Skip unknown content.
1742         if (Stream.SkipBlock())
1743           return Error("Malformed block record");
1744         break;
1745       }
1746       continue;
1747     }
1748 
1749     if (Code == bitc::DEFINE_ABBREV) {
1750       Stream.ReadAbbrevRecord();
1751       continue;
1752     }
1753 
1754     // Read a record.
1755     switch (Stream.ReadRecord(Code, Record)) {
1756     default: break;  // Default behavior, ignore unknown content.
1757     case bitc::MODULE_CODE_VERSION:  // VERSION: [version#]
1758       if (Record.size() < 1)
1759         return Error("Malformed MODULE_CODE_VERSION");
1760       // Only version #0 is supported so far.
1761       if (Record[0] != 0)
1762         return Error("Unknown bitstream version!");
1763       break;
1764     case bitc::MODULE_CODE_TRIPLE: {  // TRIPLE: [strchr x N]
1765       std::string S;
1766       if (ConvertToString(Record, 0, S))
1767         return Error("Invalid MODULE_CODE_TRIPLE record");
1768       Triple = S;
1769       break;
1770     }
1771     }
1772     Record.clear();
1773   }
1774 
1775   return Error("Premature end of bitstream");
1776 }
1777 
1778 bool BitcodeReader::ParseTriple(std::string &Triple) {
1779   if (Buffer->getBufferSize() & 3)
1780     return Error("Bitcode stream should be a multiple of 4 bytes in length");
1781 
1782   unsigned char *BufPtr = (unsigned char *)Buffer->getBufferStart();
1783   unsigned char *BufEnd = BufPtr+Buffer->getBufferSize();
1784 
1785   // If we have a wrapper header, parse it and ignore the non-bc file contents.
1786   // The magic number is 0x0B17C0DE stored in little endian.
1787   if (isBitcodeWrapper(BufPtr, BufEnd))
1788     if (SkipBitcodeWrapperHeader(BufPtr, BufEnd))
1789       return Error("Invalid bitcode wrapper header");
1790 
1791   StreamFile.init(BufPtr, BufEnd);
1792   Stream.init(StreamFile);
1793 
1794   // Sniff for the signature.
1795   if (Stream.Read(8) != 'B' ||
1796       Stream.Read(8) != 'C' ||
1797       Stream.Read(4) != 0x0 ||
1798       Stream.Read(4) != 0xC ||
1799       Stream.Read(4) != 0xE ||
1800       Stream.Read(4) != 0xD)
1801     return Error("Invalid bitcode signature");
1802 
1803   // We expect a number of well-defined blocks, though we don't necessarily
1804   // need to understand them all.
1805   while (!Stream.AtEndOfStream()) {
1806     unsigned Code = Stream.ReadCode();
1807 
1808     if (Code != bitc::ENTER_SUBBLOCK)
1809       return Error("Invalid record at top-level");
1810 
1811     unsigned BlockID = Stream.ReadSubBlockID();
1812 
1813     // We only know the MODULE subblock ID.
1814     switch (BlockID) {
1815     case bitc::MODULE_BLOCK_ID:
1816       if (ParseModuleTriple(Triple))
1817         return true;
1818       break;
1819     default:
1820       if (Stream.SkipBlock())
1821         return Error("Malformed block record");
1822       break;
1823     }
1824   }
1825 
1826   return false;
1827 }
1828 
1829 /// ParseMetadataAttachment - Parse metadata attachments.
1830 bool BitcodeReader::ParseMetadataAttachment() {
1831   if (Stream.EnterSubBlock(bitc::METADATA_ATTACHMENT_ID))
1832     return Error("Malformed block record");
1833 
1834   SmallVector<uint64_t, 64> Record;
1835   while(1) {
1836     unsigned Code = Stream.ReadCode();
1837     if (Code == bitc::END_BLOCK) {
1838       if (Stream.ReadBlockEnd())
1839         return Error("Error at end of PARAMATTR block");
1840       break;
1841     }
1842     if (Code == bitc::DEFINE_ABBREV) {
1843       Stream.ReadAbbrevRecord();
1844       continue;
1845     }
1846     // Read a metadata attachment record.
1847     Record.clear();
1848     switch (Stream.ReadRecord(Code, Record)) {
1849     default:  // Default behavior: ignore.
1850       break;
1851     case bitc::METADATA_ATTACHMENT: {
1852       unsigned RecordLength = Record.size();
1853       if (Record.empty() || (RecordLength - 1) % 2 == 1)
1854         return Error ("Invalid METADATA_ATTACHMENT reader!");
1855       Instruction *Inst = InstructionList[Record[0]];
1856       for (unsigned i = 1; i != RecordLength; i = i+2) {
1857         unsigned Kind = Record[i];
1858         DenseMap<unsigned, unsigned>::iterator I =
1859           MDKindMap.find(Kind);
1860         if (I == MDKindMap.end())
1861           return Error("Invalid metadata kind ID");
1862         Value *Node = MDValueList.getValueFwdRef(Record[i+1]);
1863         Inst->setMetadata(I->second, cast<MDNode>(Node));
1864       }
1865       break;
1866     }
1867     }
1868   }
1869   return false;
1870 }
1871 
1872 /// ParseFunctionBody - Lazily parse the specified function body block.
1873 bool BitcodeReader::ParseFunctionBody(Function *F) {
1874   if (Stream.EnterSubBlock(bitc::FUNCTION_BLOCK_ID))
1875     return Error("Malformed block record");
1876 
1877   InstructionList.clear();
1878   unsigned ModuleValueListSize = ValueList.size();
1879   unsigned ModuleMDValueListSize = MDValueList.size();
1880 
1881   // Add all the function arguments to the value table.
1882   for(Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
1883     ValueList.push_back(I);
1884 
1885   unsigned NextValueNo = ValueList.size();
1886   BasicBlock *CurBB = 0;
1887   unsigned CurBBNo = 0;
1888 
1889   DebugLoc LastLoc;
1890 
1891   // Read all the records.
1892   SmallVector<uint64_t, 64> Record;
1893   while (1) {
1894     unsigned Code = Stream.ReadCode();
1895     if (Code == bitc::END_BLOCK) {
1896       if (Stream.ReadBlockEnd())
1897         return Error("Error at end of function block");
1898       break;
1899     }
1900 
1901     if (Code == bitc::ENTER_SUBBLOCK) {
1902       switch (Stream.ReadSubBlockID()) {
1903       default:  // Skip unknown content.
1904         if (Stream.SkipBlock())
1905           return Error("Malformed block record");
1906         break;
1907       case bitc::CONSTANTS_BLOCK_ID:
1908         if (ParseConstants()) return true;
1909         NextValueNo = ValueList.size();
1910         break;
1911       case bitc::VALUE_SYMTAB_BLOCK_ID:
1912         if (ParseValueSymbolTable()) return true;
1913         break;
1914       case bitc::METADATA_ATTACHMENT_ID:
1915         if (ParseMetadataAttachment()) return true;
1916         break;
1917       case bitc::METADATA_BLOCK_ID:
1918         if (ParseMetadata()) return true;
1919         break;
1920       }
1921       continue;
1922     }
1923 
1924     if (Code == bitc::DEFINE_ABBREV) {
1925       Stream.ReadAbbrevRecord();
1926       continue;
1927     }
1928 
1929     // Read a record.
1930     Record.clear();
1931     Instruction *I = 0;
1932     unsigned BitCode = Stream.ReadRecord(Code, Record);
1933     switch (BitCode) {
1934     default: // Default behavior: reject
1935       return Error("Unknown instruction");
1936     case bitc::FUNC_CODE_DECLAREBLOCKS:     // DECLAREBLOCKS: [nblocks]
1937       if (Record.size() < 1 || Record[0] == 0)
1938         return Error("Invalid DECLAREBLOCKS record");
1939       // Create all the basic blocks for the function.
1940       FunctionBBs.resize(Record[0]);
1941       for (unsigned i = 0, e = FunctionBBs.size(); i != e; ++i)
1942         FunctionBBs[i] = BasicBlock::Create(Context, "", F);
1943       CurBB = FunctionBBs[0];
1944       continue;
1945 
1946     case bitc::FUNC_CODE_DEBUG_LOC_AGAIN:  // DEBUG_LOC_AGAIN
1947       // This record indicates that the last instruction is at the same
1948       // location as the previous instruction with a location.
1949       I = 0;
1950 
1951       // Get the last instruction emitted.
1952       if (CurBB && !CurBB->empty())
1953         I = &CurBB->back();
1954       else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
1955                !FunctionBBs[CurBBNo-1]->empty())
1956         I = &FunctionBBs[CurBBNo-1]->back();
1957 
1958       if (I == 0) return Error("Invalid DEBUG_LOC_AGAIN record");
1959       I->setDebugLoc(LastLoc);
1960       I = 0;
1961       continue;
1962 
1963     case bitc::FUNC_CODE_DEBUG_LOC: {      // DEBUG_LOC: [line, col, scope, ia]
1964       I = 0;     // Get the last instruction emitted.
1965       if (CurBB && !CurBB->empty())
1966         I = &CurBB->back();
1967       else if (CurBBNo && FunctionBBs[CurBBNo-1] &&
1968                !FunctionBBs[CurBBNo-1]->empty())
1969         I = &FunctionBBs[CurBBNo-1]->back();
1970       if (I == 0 || Record.size() < 4)
1971         return Error("Invalid FUNC_CODE_DEBUG_LOC record");
1972 
1973       unsigned Line = Record[0], Col = Record[1];
1974       unsigned ScopeID = Record[2], IAID = Record[3];
1975 
1976       MDNode *Scope = 0, *IA = 0;
1977       if (ScopeID) Scope = cast<MDNode>(MDValueList.getValueFwdRef(ScopeID-1));
1978       if (IAID)    IA = cast<MDNode>(MDValueList.getValueFwdRef(IAID-1));
1979       LastLoc = DebugLoc::get(Line, Col, Scope, IA);
1980       I->setDebugLoc(LastLoc);
1981       I = 0;
1982       continue;
1983     }
1984 
1985     case bitc::FUNC_CODE_INST_BINOP: {    // BINOP: [opval, ty, opval, opcode]
1986       unsigned OpNum = 0;
1987       Value *LHS, *RHS;
1988       if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
1989           getValue(Record, OpNum, LHS->getType(), RHS) ||
1990           OpNum+1 > Record.size())
1991         return Error("Invalid BINOP record");
1992 
1993       int Opc = GetDecodedBinaryOpcode(Record[OpNum++], LHS->getType());
1994       if (Opc == -1) return Error("Invalid BINOP record");
1995       I = BinaryOperator::Create((Instruction::BinaryOps)Opc, LHS, RHS);
1996       InstructionList.push_back(I);
1997       if (OpNum < Record.size()) {
1998         if (Opc == Instruction::Add ||
1999             Opc == Instruction::Sub ||
2000             Opc == Instruction::Mul ||
2001             Opc == Instruction::Shl) {
2002           if (Record[OpNum] & (1 << bitc::OBO_NO_SIGNED_WRAP))
2003             cast<BinaryOperator>(I)->setHasNoSignedWrap(true);
2004           if (Record[OpNum] & (1 << bitc::OBO_NO_UNSIGNED_WRAP))
2005             cast<BinaryOperator>(I)->setHasNoUnsignedWrap(true);
2006         } else if (Opc == Instruction::SDiv ||
2007                    Opc == Instruction::UDiv ||
2008                    Opc == Instruction::LShr ||
2009                    Opc == Instruction::AShr) {
2010           if (Record[OpNum] & (1 << bitc::PEO_EXACT))
2011             cast<BinaryOperator>(I)->setIsExact(true);
2012         }
2013       }
2014       break;
2015     }
2016     case bitc::FUNC_CODE_INST_CAST: {    // CAST: [opval, opty, destty, castopc]
2017       unsigned OpNum = 0;
2018       Value *Op;
2019       if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2020           OpNum+2 != Record.size())
2021         return Error("Invalid CAST record");
2022 
2023       Type *ResTy = getTypeByID(Record[OpNum]);
2024       int Opc = GetDecodedCastOpcode(Record[OpNum+1]);
2025       if (Opc == -1 || ResTy == 0)
2026         return Error("Invalid CAST record");
2027       I = CastInst::Create((Instruction::CastOps)Opc, Op, ResTy);
2028       InstructionList.push_back(I);
2029       break;
2030     }
2031     case bitc::FUNC_CODE_INST_INBOUNDS_GEP:
2032     case bitc::FUNC_CODE_INST_GEP: { // GEP: [n x operands]
2033       unsigned OpNum = 0;
2034       Value *BasePtr;
2035       if (getValueTypePair(Record, OpNum, NextValueNo, BasePtr))
2036         return Error("Invalid GEP record");
2037 
2038       SmallVector<Value*, 16> GEPIdx;
2039       while (OpNum != Record.size()) {
2040         Value *Op;
2041         if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2042           return Error("Invalid GEP record");
2043         GEPIdx.push_back(Op);
2044       }
2045 
2046       I = GetElementPtrInst::Create(BasePtr, GEPIdx);
2047       InstructionList.push_back(I);
2048       if (BitCode == bitc::FUNC_CODE_INST_INBOUNDS_GEP)
2049         cast<GetElementPtrInst>(I)->setIsInBounds(true);
2050       break;
2051     }
2052 
2053     case bitc::FUNC_CODE_INST_EXTRACTVAL: {
2054                                        // EXTRACTVAL: [opty, opval, n x indices]
2055       unsigned OpNum = 0;
2056       Value *Agg;
2057       if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2058         return Error("Invalid EXTRACTVAL record");
2059 
2060       SmallVector<unsigned, 4> EXTRACTVALIdx;
2061       for (unsigned RecSize = Record.size();
2062            OpNum != RecSize; ++OpNum) {
2063         uint64_t Index = Record[OpNum];
2064         if ((unsigned)Index != Index)
2065           return Error("Invalid EXTRACTVAL index");
2066         EXTRACTVALIdx.push_back((unsigned)Index);
2067       }
2068 
2069       I = ExtractValueInst::Create(Agg, EXTRACTVALIdx);
2070       InstructionList.push_back(I);
2071       break;
2072     }
2073 
2074     case bitc::FUNC_CODE_INST_INSERTVAL: {
2075                            // INSERTVAL: [opty, opval, opty, opval, n x indices]
2076       unsigned OpNum = 0;
2077       Value *Agg;
2078       if (getValueTypePair(Record, OpNum, NextValueNo, Agg))
2079         return Error("Invalid INSERTVAL record");
2080       Value *Val;
2081       if (getValueTypePair(Record, OpNum, NextValueNo, Val))
2082         return Error("Invalid INSERTVAL record");
2083 
2084       SmallVector<unsigned, 4> INSERTVALIdx;
2085       for (unsigned RecSize = Record.size();
2086            OpNum != RecSize; ++OpNum) {
2087         uint64_t Index = Record[OpNum];
2088         if ((unsigned)Index != Index)
2089           return Error("Invalid INSERTVAL index");
2090         INSERTVALIdx.push_back((unsigned)Index);
2091       }
2092 
2093       I = InsertValueInst::Create(Agg, Val, INSERTVALIdx);
2094       InstructionList.push_back(I);
2095       break;
2096     }
2097 
2098     case bitc::FUNC_CODE_INST_SELECT: { // SELECT: [opval, ty, opval, opval]
2099       // obsolete form of select
2100       // handles select i1 ... in old bitcode
2101       unsigned OpNum = 0;
2102       Value *TrueVal, *FalseVal, *Cond;
2103       if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2104           getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
2105           getValue(Record, OpNum, Type::getInt1Ty(Context), Cond))
2106         return Error("Invalid SELECT record");
2107 
2108       I = SelectInst::Create(Cond, TrueVal, FalseVal);
2109       InstructionList.push_back(I);
2110       break;
2111     }
2112 
2113     case bitc::FUNC_CODE_INST_VSELECT: {// VSELECT: [ty,opval,opval,predty,pred]
2114       // new form of select
2115       // handles select i1 or select [N x i1]
2116       unsigned OpNum = 0;
2117       Value *TrueVal, *FalseVal, *Cond;
2118       if (getValueTypePair(Record, OpNum, NextValueNo, TrueVal) ||
2119           getValue(Record, OpNum, TrueVal->getType(), FalseVal) ||
2120           getValueTypePair(Record, OpNum, NextValueNo, Cond))
2121         return Error("Invalid SELECT record");
2122 
2123       // select condition can be either i1 or [N x i1]
2124       if (VectorType* vector_type =
2125           dyn_cast<VectorType>(Cond->getType())) {
2126         // expect <n x i1>
2127         if (vector_type->getElementType() != Type::getInt1Ty(Context))
2128           return Error("Invalid SELECT condition type");
2129       } else {
2130         // expect i1
2131         if (Cond->getType() != Type::getInt1Ty(Context))
2132           return Error("Invalid SELECT condition type");
2133       }
2134 
2135       I = SelectInst::Create(Cond, TrueVal, FalseVal);
2136       InstructionList.push_back(I);
2137       break;
2138     }
2139 
2140     case bitc::FUNC_CODE_INST_EXTRACTELT: { // EXTRACTELT: [opty, opval, opval]
2141       unsigned OpNum = 0;
2142       Value *Vec, *Idx;
2143       if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2144           getValue(Record, OpNum, Type::getInt32Ty(Context), Idx))
2145         return Error("Invalid EXTRACTELT record");
2146       I = ExtractElementInst::Create(Vec, Idx);
2147       InstructionList.push_back(I);
2148       break;
2149     }
2150 
2151     case bitc::FUNC_CODE_INST_INSERTELT: { // INSERTELT: [ty, opval,opval,opval]
2152       unsigned OpNum = 0;
2153       Value *Vec, *Elt, *Idx;
2154       if (getValueTypePair(Record, OpNum, NextValueNo, Vec) ||
2155           getValue(Record, OpNum,
2156                    cast<VectorType>(Vec->getType())->getElementType(), Elt) ||
2157           getValue(Record, OpNum, Type::getInt32Ty(Context), Idx))
2158         return Error("Invalid INSERTELT record");
2159       I = InsertElementInst::Create(Vec, Elt, Idx);
2160       InstructionList.push_back(I);
2161       break;
2162     }
2163 
2164     case bitc::FUNC_CODE_INST_SHUFFLEVEC: {// SHUFFLEVEC: [opval,ty,opval,opval]
2165       unsigned OpNum = 0;
2166       Value *Vec1, *Vec2, *Mask;
2167       if (getValueTypePair(Record, OpNum, NextValueNo, Vec1) ||
2168           getValue(Record, OpNum, Vec1->getType(), Vec2))
2169         return Error("Invalid SHUFFLEVEC record");
2170 
2171       if (getValueTypePair(Record, OpNum, NextValueNo, Mask))
2172         return Error("Invalid SHUFFLEVEC record");
2173       I = new ShuffleVectorInst(Vec1, Vec2, Mask);
2174       InstructionList.push_back(I);
2175       break;
2176     }
2177 
2178     case bitc::FUNC_CODE_INST_CMP:   // CMP: [opty, opval, opval, pred]
2179       // Old form of ICmp/FCmp returning bool
2180       // Existed to differentiate between icmp/fcmp and vicmp/vfcmp which were
2181       // both legal on vectors but had different behaviour.
2182     case bitc::FUNC_CODE_INST_CMP2: { // CMP2: [opty, opval, opval, pred]
2183       // FCmp/ICmp returning bool or vector of bool
2184 
2185       unsigned OpNum = 0;
2186       Value *LHS, *RHS;
2187       if (getValueTypePair(Record, OpNum, NextValueNo, LHS) ||
2188           getValue(Record, OpNum, LHS->getType(), RHS) ||
2189           OpNum+1 != Record.size())
2190         return Error("Invalid CMP record");
2191 
2192       if (LHS->getType()->isFPOrFPVectorTy())
2193         I = new FCmpInst((FCmpInst::Predicate)Record[OpNum], LHS, RHS);
2194       else
2195         I = new ICmpInst((ICmpInst::Predicate)Record[OpNum], LHS, RHS);
2196       InstructionList.push_back(I);
2197       break;
2198     }
2199 
2200     case bitc::FUNC_CODE_INST_RET: // RET: [opty,opval<optional>]
2201       {
2202         unsigned Size = Record.size();
2203         if (Size == 0) {
2204           I = ReturnInst::Create(Context);
2205           InstructionList.push_back(I);
2206           break;
2207         }
2208 
2209         unsigned OpNum = 0;
2210         Value *Op = NULL;
2211         if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2212           return Error("Invalid RET record");
2213         if (OpNum != Record.size())
2214           return Error("Invalid RET record");
2215 
2216         I = ReturnInst::Create(Context, Op);
2217         InstructionList.push_back(I);
2218         break;
2219       }
2220     case bitc::FUNC_CODE_INST_BR: { // BR: [bb#, bb#, opval] or [bb#]
2221       if (Record.size() != 1 && Record.size() != 3)
2222         return Error("Invalid BR record");
2223       BasicBlock *TrueDest = getBasicBlock(Record[0]);
2224       if (TrueDest == 0)
2225         return Error("Invalid BR record");
2226 
2227       if (Record.size() == 1) {
2228         I = BranchInst::Create(TrueDest);
2229         InstructionList.push_back(I);
2230       }
2231       else {
2232         BasicBlock *FalseDest = getBasicBlock(Record[1]);
2233         Value *Cond = getFnValueByID(Record[2], Type::getInt1Ty(Context));
2234         if (FalseDest == 0 || Cond == 0)
2235           return Error("Invalid BR record");
2236         I = BranchInst::Create(TrueDest, FalseDest, Cond);
2237         InstructionList.push_back(I);
2238       }
2239       break;
2240     }
2241     case bitc::FUNC_CODE_INST_SWITCH: { // SWITCH: [opty, op0, op1, ...]
2242       if (Record.size() < 3 || (Record.size() & 1) == 0)
2243         return Error("Invalid SWITCH record");
2244       Type *OpTy = getTypeByID(Record[0]);
2245       Value *Cond = getFnValueByID(Record[1], OpTy);
2246       BasicBlock *Default = getBasicBlock(Record[2]);
2247       if (OpTy == 0 || Cond == 0 || Default == 0)
2248         return Error("Invalid SWITCH record");
2249       unsigned NumCases = (Record.size()-3)/2;
2250       SwitchInst *SI = SwitchInst::Create(Cond, Default, NumCases);
2251       InstructionList.push_back(SI);
2252       for (unsigned i = 0, e = NumCases; i != e; ++i) {
2253         ConstantInt *CaseVal =
2254           dyn_cast_or_null<ConstantInt>(getFnValueByID(Record[3+i*2], OpTy));
2255         BasicBlock *DestBB = getBasicBlock(Record[1+3+i*2]);
2256         if (CaseVal == 0 || DestBB == 0) {
2257           delete SI;
2258           return Error("Invalid SWITCH record!");
2259         }
2260         SI->addCase(CaseVal, DestBB);
2261       }
2262       I = SI;
2263       break;
2264     }
2265     case bitc::FUNC_CODE_INST_INDIRECTBR: { // INDIRECTBR: [opty, op0, op1, ...]
2266       if (Record.size() < 2)
2267         return Error("Invalid INDIRECTBR record");
2268       Type *OpTy = getTypeByID(Record[0]);
2269       Value *Address = getFnValueByID(Record[1], OpTy);
2270       if (OpTy == 0 || Address == 0)
2271         return Error("Invalid INDIRECTBR record");
2272       unsigned NumDests = Record.size()-2;
2273       IndirectBrInst *IBI = IndirectBrInst::Create(Address, NumDests);
2274       InstructionList.push_back(IBI);
2275       for (unsigned i = 0, e = NumDests; i != e; ++i) {
2276         if (BasicBlock *DestBB = getBasicBlock(Record[2+i])) {
2277           IBI->addDestination(DestBB);
2278         } else {
2279           delete IBI;
2280           return Error("Invalid INDIRECTBR record!");
2281         }
2282       }
2283       I = IBI;
2284       break;
2285     }
2286 
2287     case bitc::FUNC_CODE_INST_INVOKE: {
2288       // INVOKE: [attrs, cc, normBB, unwindBB, fnty, op0,op1,op2, ...]
2289       if (Record.size() < 4) return Error("Invalid INVOKE record");
2290       AttrListPtr PAL = getAttributes(Record[0]);
2291       unsigned CCInfo = Record[1];
2292       BasicBlock *NormalBB = getBasicBlock(Record[2]);
2293       BasicBlock *UnwindBB = getBasicBlock(Record[3]);
2294 
2295       unsigned OpNum = 4;
2296       Value *Callee;
2297       if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
2298         return Error("Invalid INVOKE record");
2299 
2300       PointerType *CalleeTy = dyn_cast<PointerType>(Callee->getType());
2301       FunctionType *FTy = !CalleeTy ? 0 :
2302         dyn_cast<FunctionType>(CalleeTy->getElementType());
2303 
2304       // Check that the right number of fixed parameters are here.
2305       if (FTy == 0 || NormalBB == 0 || UnwindBB == 0 ||
2306           Record.size() < OpNum+FTy->getNumParams())
2307         return Error("Invalid INVOKE record");
2308 
2309       SmallVector<Value*, 16> Ops;
2310       for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
2311         Ops.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
2312         if (Ops.back() == 0) return Error("Invalid INVOKE record");
2313       }
2314 
2315       if (!FTy->isVarArg()) {
2316         if (Record.size() != OpNum)
2317           return Error("Invalid INVOKE record");
2318       } else {
2319         // Read type/value pairs for varargs params.
2320         while (OpNum != Record.size()) {
2321           Value *Op;
2322           if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2323             return Error("Invalid INVOKE record");
2324           Ops.push_back(Op);
2325         }
2326       }
2327 
2328       I = InvokeInst::Create(Callee, NormalBB, UnwindBB, Ops);
2329       InstructionList.push_back(I);
2330       cast<InvokeInst>(I)->setCallingConv(
2331         static_cast<CallingConv::ID>(CCInfo));
2332       cast<InvokeInst>(I)->setAttributes(PAL);
2333       break;
2334     }
2335     case bitc::FUNC_CODE_INST_RESUME: { // RESUME: [opval]
2336       unsigned Idx = 0;
2337       Value *Val = 0;
2338       if (getValueTypePair(Record, Idx, NextValueNo, Val))
2339         return Error("Invalid RESUME record");
2340       I = ResumeInst::Create(Val);
2341       InstructionList.push_back(I);
2342       break;
2343     }
2344     case bitc::FUNC_CODE_INST_UNWIND: // UNWIND
2345       I = new UnwindInst(Context);
2346       InstructionList.push_back(I);
2347       break;
2348     case bitc::FUNC_CODE_INST_UNREACHABLE: // UNREACHABLE
2349       I = new UnreachableInst(Context);
2350       InstructionList.push_back(I);
2351       break;
2352     case bitc::FUNC_CODE_INST_PHI: { // PHI: [ty, val0,bb0, ...]
2353       if (Record.size() < 1 || ((Record.size()-1)&1))
2354         return Error("Invalid PHI record");
2355       Type *Ty = getTypeByID(Record[0]);
2356       if (!Ty) return Error("Invalid PHI record");
2357 
2358       PHINode *PN = PHINode::Create(Ty, (Record.size()-1)/2);
2359       InstructionList.push_back(PN);
2360 
2361       for (unsigned i = 0, e = Record.size()-1; i != e; i += 2) {
2362         Value *V = getFnValueByID(Record[1+i], Ty);
2363         BasicBlock *BB = getBasicBlock(Record[2+i]);
2364         if (!V || !BB) return Error("Invalid PHI record");
2365         PN->addIncoming(V, BB);
2366       }
2367       I = PN;
2368       break;
2369     }
2370 
2371     case bitc::FUNC_CODE_INST_LANDINGPAD: {
2372       // LANDINGPAD: [ty, val, val, num, (id0,val0 ...)?]
2373       unsigned Idx = 0;
2374       if (Record.size() < 4)
2375         return Error("Invalid LANDINGPAD record");
2376       Type *Ty = getTypeByID(Record[Idx++]);
2377       if (!Ty) return Error("Invalid LANDINGPAD record");
2378       Value *PersFn = 0;
2379       if (getValueTypePair(Record, Idx, NextValueNo, PersFn))
2380         return Error("Invalid LANDINGPAD record");
2381 
2382       bool IsCleanup = !!Record[Idx++];
2383       unsigned NumClauses = Record[Idx++];
2384       LandingPadInst *LP = LandingPadInst::Create(Ty, PersFn, NumClauses);
2385       LP->setCleanup(IsCleanup);
2386       for (unsigned J = 0; J != NumClauses; ++J) {
2387         LandingPadInst::ClauseType CT =
2388           LandingPadInst::ClauseType(Record[Idx++]); (void)CT;
2389         Value *Val;
2390 
2391         if (getValueTypePair(Record, Idx, NextValueNo, Val)) {
2392           delete LP;
2393           return Error("Invalid LANDINGPAD record");
2394         }
2395 
2396         assert((CT != LandingPadInst::Catch ||
2397                 !isa<ArrayType>(Val->getType())) &&
2398                "Catch clause has a invalid type!");
2399         assert((CT != LandingPadInst::Filter ||
2400                 isa<ArrayType>(Val->getType())) &&
2401                "Filter clause has invalid type!");
2402         LP->addClause(Val);
2403       }
2404 
2405       I = LP;
2406       InstructionList.push_back(I);
2407       break;
2408     }
2409 
2410     case bitc::FUNC_CODE_INST_ALLOCA: { // ALLOCA: [instty, opty, op, align]
2411       if (Record.size() != 4)
2412         return Error("Invalid ALLOCA record");
2413       PointerType *Ty =
2414         dyn_cast_or_null<PointerType>(getTypeByID(Record[0]));
2415       Type *OpTy = getTypeByID(Record[1]);
2416       Value *Size = getFnValueByID(Record[2], OpTy);
2417       unsigned Align = Record[3];
2418       if (!Ty || !Size) return Error("Invalid ALLOCA record");
2419       I = new AllocaInst(Ty->getElementType(), Size, (1 << Align) >> 1);
2420       InstructionList.push_back(I);
2421       break;
2422     }
2423     case bitc::FUNC_CODE_INST_LOAD: { // LOAD: [opty, op, align, vol]
2424       unsigned OpNum = 0;
2425       Value *Op;
2426       if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2427           OpNum+2 != Record.size())
2428         return Error("Invalid LOAD record");
2429 
2430       I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1);
2431       InstructionList.push_back(I);
2432       break;
2433     }
2434     case bitc::FUNC_CODE_INST_LOADATOMIC: {
2435        // LOADATOMIC: [opty, op, align, vol, ordering, synchscope]
2436       unsigned OpNum = 0;
2437       Value *Op;
2438       if (getValueTypePair(Record, OpNum, NextValueNo, Op) ||
2439           OpNum+4 != Record.size())
2440         return Error("Invalid LOADATOMIC record");
2441 
2442 
2443       AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2444       if (Ordering == NotAtomic || Ordering == Release ||
2445           Ordering == AcquireRelease)
2446         return Error("Invalid LOADATOMIC record");
2447       if (Ordering != NotAtomic && Record[OpNum] == 0)
2448         return Error("Invalid LOADATOMIC record");
2449       SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2450 
2451       I = new LoadInst(Op, "", Record[OpNum+1], (1 << Record[OpNum]) >> 1,
2452                        Ordering, SynchScope);
2453       InstructionList.push_back(I);
2454       break;
2455     }
2456     case bitc::FUNC_CODE_INST_STORE: { // STORE2:[ptrty, ptr, val, align, vol]
2457       unsigned OpNum = 0;
2458       Value *Val, *Ptr;
2459       if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2460           getValue(Record, OpNum,
2461                     cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2462           OpNum+2 != Record.size())
2463         return Error("Invalid STORE record");
2464 
2465       I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1);
2466       InstructionList.push_back(I);
2467       break;
2468     }
2469     case bitc::FUNC_CODE_INST_STOREATOMIC: {
2470       // STOREATOMIC: [ptrty, ptr, val, align, vol, ordering, synchscope]
2471       unsigned OpNum = 0;
2472       Value *Val, *Ptr;
2473       if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2474           getValue(Record, OpNum,
2475                     cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2476           OpNum+4 != Record.size())
2477         return Error("Invalid STOREATOMIC record");
2478 
2479       AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2480       if (Ordering == NotAtomic || Ordering == Acquire ||
2481           Ordering == AcquireRelease)
2482         return Error("Invalid STOREATOMIC record");
2483       SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2484       if (Ordering != NotAtomic && Record[OpNum] == 0)
2485         return Error("Invalid STOREATOMIC record");
2486 
2487       I = new StoreInst(Val, Ptr, Record[OpNum+1], (1 << Record[OpNum]) >> 1,
2488                         Ordering, SynchScope);
2489       InstructionList.push_back(I);
2490       break;
2491     }
2492     case bitc::FUNC_CODE_INST_CMPXCHG: {
2493       // CMPXCHG:[ptrty, ptr, cmp, new, vol, ordering, synchscope]
2494       unsigned OpNum = 0;
2495       Value *Ptr, *Cmp, *New;
2496       if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2497           getValue(Record, OpNum,
2498                     cast<PointerType>(Ptr->getType())->getElementType(), Cmp) ||
2499           getValue(Record, OpNum,
2500                     cast<PointerType>(Ptr->getType())->getElementType(), New) ||
2501           OpNum+3 != Record.size())
2502         return Error("Invalid CMPXCHG record");
2503       AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+1]);
2504       if (Ordering == NotAtomic || Ordering == Unordered)
2505         return Error("Invalid CMPXCHG record");
2506       SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+2]);
2507       I = new AtomicCmpXchgInst(Ptr, Cmp, New, Ordering, SynchScope);
2508       cast<AtomicCmpXchgInst>(I)->setVolatile(Record[OpNum]);
2509       InstructionList.push_back(I);
2510       break;
2511     }
2512     case bitc::FUNC_CODE_INST_ATOMICRMW: {
2513       // ATOMICRMW:[ptrty, ptr, val, op, vol, ordering, synchscope]
2514       unsigned OpNum = 0;
2515       Value *Ptr, *Val;
2516       if (getValueTypePair(Record, OpNum, NextValueNo, Ptr) ||
2517           getValue(Record, OpNum,
2518                     cast<PointerType>(Ptr->getType())->getElementType(), Val) ||
2519           OpNum+4 != Record.size())
2520         return Error("Invalid ATOMICRMW record");
2521       AtomicRMWInst::BinOp Operation = GetDecodedRMWOperation(Record[OpNum]);
2522       if (Operation < AtomicRMWInst::FIRST_BINOP ||
2523           Operation > AtomicRMWInst::LAST_BINOP)
2524         return Error("Invalid ATOMICRMW record");
2525       AtomicOrdering Ordering = GetDecodedOrdering(Record[OpNum+2]);
2526       if (Ordering == NotAtomic || Ordering == Unordered)
2527         return Error("Invalid ATOMICRMW record");
2528       SynchronizationScope SynchScope = GetDecodedSynchScope(Record[OpNum+3]);
2529       I = new AtomicRMWInst(Operation, Ptr, Val, Ordering, SynchScope);
2530       cast<AtomicRMWInst>(I)->setVolatile(Record[OpNum+1]);
2531       InstructionList.push_back(I);
2532       break;
2533     }
2534     case bitc::FUNC_CODE_INST_FENCE: { // FENCE:[ordering, synchscope]
2535       if (2 != Record.size())
2536         return Error("Invalid FENCE record");
2537       AtomicOrdering Ordering = GetDecodedOrdering(Record[0]);
2538       if (Ordering == NotAtomic || Ordering == Unordered ||
2539           Ordering == Monotonic)
2540         return Error("Invalid FENCE record");
2541       SynchronizationScope SynchScope = GetDecodedSynchScope(Record[1]);
2542       I = new FenceInst(Context, Ordering, SynchScope);
2543       InstructionList.push_back(I);
2544       break;
2545     }
2546     case bitc::FUNC_CODE_INST_CALL: {
2547       // CALL: [paramattrs, cc, fnty, fnid, arg0, arg1...]
2548       if (Record.size() < 3)
2549         return Error("Invalid CALL record");
2550 
2551       AttrListPtr PAL = getAttributes(Record[0]);
2552       unsigned CCInfo = Record[1];
2553 
2554       unsigned OpNum = 2;
2555       Value *Callee;
2556       if (getValueTypePair(Record, OpNum, NextValueNo, Callee))
2557         return Error("Invalid CALL record");
2558 
2559       PointerType *OpTy = dyn_cast<PointerType>(Callee->getType());
2560       FunctionType *FTy = 0;
2561       if (OpTy) FTy = dyn_cast<FunctionType>(OpTy->getElementType());
2562       if (!FTy || Record.size() < FTy->getNumParams()+OpNum)
2563         return Error("Invalid CALL record");
2564 
2565       SmallVector<Value*, 16> Args;
2566       // Read the fixed params.
2567       for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i, ++OpNum) {
2568         if (FTy->getParamType(i)->isLabelTy())
2569           Args.push_back(getBasicBlock(Record[OpNum]));
2570         else
2571           Args.push_back(getFnValueByID(Record[OpNum], FTy->getParamType(i)));
2572         if (Args.back() == 0) return Error("Invalid CALL record");
2573       }
2574 
2575       // Read type/value pairs for varargs params.
2576       if (!FTy->isVarArg()) {
2577         if (OpNum != Record.size())
2578           return Error("Invalid CALL record");
2579       } else {
2580         while (OpNum != Record.size()) {
2581           Value *Op;
2582           if (getValueTypePair(Record, OpNum, NextValueNo, Op))
2583             return Error("Invalid CALL record");
2584           Args.push_back(Op);
2585         }
2586       }
2587 
2588       I = CallInst::Create(Callee, Args);
2589       InstructionList.push_back(I);
2590       cast<CallInst>(I)->setCallingConv(
2591         static_cast<CallingConv::ID>(CCInfo>>1));
2592       cast<CallInst>(I)->setTailCall(CCInfo & 1);
2593       cast<CallInst>(I)->setAttributes(PAL);
2594       break;
2595     }
2596     case bitc::FUNC_CODE_INST_VAARG: { // VAARG: [valistty, valist, instty]
2597       if (Record.size() < 3)
2598         return Error("Invalid VAARG record");
2599       Type *OpTy = getTypeByID(Record[0]);
2600       Value *Op = getFnValueByID(Record[1], OpTy);
2601       Type *ResTy = getTypeByID(Record[2]);
2602       if (!OpTy || !Op || !ResTy)
2603         return Error("Invalid VAARG record");
2604       I = new VAArgInst(Op, ResTy);
2605       InstructionList.push_back(I);
2606       break;
2607     }
2608     }
2609 
2610     // Add instruction to end of current BB.  If there is no current BB, reject
2611     // this file.
2612     if (CurBB == 0) {
2613       delete I;
2614       return Error("Invalid instruction with no BB");
2615     }
2616     CurBB->getInstList().push_back(I);
2617 
2618     // If this was a terminator instruction, move to the next block.
2619     if (isa<TerminatorInst>(I)) {
2620       ++CurBBNo;
2621       CurBB = CurBBNo < FunctionBBs.size() ? FunctionBBs[CurBBNo] : 0;
2622     }
2623 
2624     // Non-void values get registered in the value table for future use.
2625     if (I && !I->getType()->isVoidTy())
2626       ValueList.AssignValue(I, NextValueNo++);
2627   }
2628 
2629   // Check the function list for unresolved values.
2630   if (Argument *A = dyn_cast<Argument>(ValueList.back())) {
2631     if (A->getParent() == 0) {
2632       // We found at least one unresolved value.  Nuke them all to avoid leaks.
2633       for (unsigned i = ModuleValueListSize, e = ValueList.size(); i != e; ++i){
2634         if ((A = dyn_cast<Argument>(ValueList[i])) && A->getParent() == 0) {
2635           A->replaceAllUsesWith(UndefValue::get(A->getType()));
2636           delete A;
2637         }
2638       }
2639       return Error("Never resolved value found in function!");
2640     }
2641   }
2642 
2643   // FIXME: Check for unresolved forward-declared metadata references
2644   // and clean up leaks.
2645 
2646   // See if anything took the address of blocks in this function.  If so,
2647   // resolve them now.
2648   DenseMap<Function*, std::vector<BlockAddrRefTy> >::iterator BAFRI =
2649     BlockAddrFwdRefs.find(F);
2650   if (BAFRI != BlockAddrFwdRefs.end()) {
2651     std::vector<BlockAddrRefTy> &RefList = BAFRI->second;
2652     for (unsigned i = 0, e = RefList.size(); i != e; ++i) {
2653       unsigned BlockIdx = RefList[i].first;
2654       if (BlockIdx >= FunctionBBs.size())
2655         return Error("Invalid blockaddress block #");
2656 
2657       GlobalVariable *FwdRef = RefList[i].second;
2658       FwdRef->replaceAllUsesWith(BlockAddress::get(F, FunctionBBs[BlockIdx]));
2659       FwdRef->eraseFromParent();
2660     }
2661 
2662     BlockAddrFwdRefs.erase(BAFRI);
2663   }
2664 
2665   // Trim the value list down to the size it was before we parsed this function.
2666   ValueList.shrinkTo(ModuleValueListSize);
2667   MDValueList.shrinkTo(ModuleMDValueListSize);
2668   std::vector<BasicBlock*>().swap(FunctionBBs);
2669   return false;
2670 }
2671 
2672 //===----------------------------------------------------------------------===//
2673 // GVMaterializer implementation
2674 //===----------------------------------------------------------------------===//
2675 
2676 
2677 bool BitcodeReader::isMaterializable(const GlobalValue *GV) const {
2678   if (const Function *F = dyn_cast<Function>(GV)) {
2679     return F->isDeclaration() &&
2680       DeferredFunctionInfo.count(const_cast<Function*>(F));
2681   }
2682   return false;
2683 }
2684 
2685 bool BitcodeReader::Materialize(GlobalValue *GV, std::string *ErrInfo) {
2686   Function *F = dyn_cast<Function>(GV);
2687   // If it's not a function or is already material, ignore the request.
2688   if (!F || !F->isMaterializable()) return false;
2689 
2690   DenseMap<Function*, uint64_t>::iterator DFII = DeferredFunctionInfo.find(F);
2691   assert(DFII != DeferredFunctionInfo.end() && "Deferred function not found!");
2692 
2693   // Move the bit stream to the saved position of the deferred function body.
2694   Stream.JumpToBit(DFII->second);
2695 
2696   if (ParseFunctionBody(F)) {
2697     if (ErrInfo) *ErrInfo = ErrorString;
2698     return true;
2699   }
2700 
2701   // Upgrade any old intrinsic calls in the function.
2702   for (UpgradedIntrinsicMap::iterator I = UpgradedIntrinsics.begin(),
2703        E = UpgradedIntrinsics.end(); I != E; ++I) {
2704     if (I->first != I->second) {
2705       for (Value::use_iterator UI = I->first->use_begin(),
2706            UE = I->first->use_end(); UI != UE; ) {
2707         if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2708           UpgradeIntrinsicCall(CI, I->second);
2709       }
2710     }
2711   }
2712 
2713   return false;
2714 }
2715 
2716 bool BitcodeReader::isDematerializable(const GlobalValue *GV) const {
2717   const Function *F = dyn_cast<Function>(GV);
2718   if (!F || F->isDeclaration())
2719     return false;
2720   return DeferredFunctionInfo.count(const_cast<Function*>(F));
2721 }
2722 
2723 void BitcodeReader::Dematerialize(GlobalValue *GV) {
2724   Function *F = dyn_cast<Function>(GV);
2725   // If this function isn't dematerializable, this is a noop.
2726   if (!F || !isDematerializable(F))
2727     return;
2728 
2729   assert(DeferredFunctionInfo.count(F) && "No info to read function later?");
2730 
2731   // Just forget the function body, we can remat it later.
2732   F->deleteBody();
2733 }
2734 
2735 
2736 bool BitcodeReader::MaterializeModule(Module *M, std::string *ErrInfo) {
2737   assert(M == TheModule &&
2738          "Can only Materialize the Module this BitcodeReader is attached to.");
2739   // Iterate over the module, deserializing any functions that are still on
2740   // disk.
2741   for (Module::iterator F = TheModule->begin(), E = TheModule->end();
2742        F != E; ++F)
2743     if (F->isMaterializable() &&
2744         Materialize(F, ErrInfo))
2745       return true;
2746 
2747   // Upgrade any intrinsic calls that slipped through (should not happen!) and
2748   // delete the old functions to clean up. We can't do this unless the entire
2749   // module is materialized because there could always be another function body
2750   // with calls to the old function.
2751   for (std::vector<std::pair<Function*, Function*> >::iterator I =
2752        UpgradedIntrinsics.begin(), E = UpgradedIntrinsics.end(); I != E; ++I) {
2753     if (I->first != I->second) {
2754       for (Value::use_iterator UI = I->first->use_begin(),
2755            UE = I->first->use_end(); UI != UE; ) {
2756         if (CallInst* CI = dyn_cast<CallInst>(*UI++))
2757           UpgradeIntrinsicCall(CI, I->second);
2758       }
2759       if (!I->first->use_empty())
2760         I->first->replaceAllUsesWith(I->second);
2761       I->first->eraseFromParent();
2762     }
2763   }
2764   std::vector<std::pair<Function*, Function*> >().swap(UpgradedIntrinsics);
2765 
2766   return false;
2767 }
2768 
2769 
2770 //===----------------------------------------------------------------------===//
2771 // External interface
2772 //===----------------------------------------------------------------------===//
2773 
2774 /// getLazyBitcodeModule - lazy function-at-a-time loading from a file.
2775 ///
2776 Module *llvm::getLazyBitcodeModule(MemoryBuffer *Buffer,
2777                                    LLVMContext& Context,
2778                                    std::string *ErrMsg) {
2779   Module *M = new Module(Buffer->getBufferIdentifier(), Context);
2780   BitcodeReader *R = new BitcodeReader(Buffer, Context);
2781   M->setMaterializer(R);
2782   if (R->ParseBitcodeInto(M)) {
2783     if (ErrMsg)
2784       *ErrMsg = R->getErrorString();
2785 
2786     delete M;  // Also deletes R.
2787     return 0;
2788   }
2789   // Have the BitcodeReader dtor delete 'Buffer'.
2790   R->setBufferOwned(true);
2791 
2792   R->materializeForwardReferencedFunctions();
2793 
2794   return M;
2795 }
2796 
2797 /// ParseBitcodeFile - Read the specified bitcode file, returning the module.
2798 /// If an error occurs, return null and fill in *ErrMsg if non-null.
2799 Module *llvm::ParseBitcodeFile(MemoryBuffer *Buffer, LLVMContext& Context,
2800                                std::string *ErrMsg){
2801   Module *M = getLazyBitcodeModule(Buffer, Context, ErrMsg);
2802   if (!M) return 0;
2803 
2804   // Don't let the BitcodeReader dtor delete 'Buffer', regardless of whether
2805   // there was an error.
2806   static_cast<BitcodeReader*>(M->getMaterializer())->setBufferOwned(false);
2807 
2808   // Read in the entire module, and destroy the BitcodeReader.
2809   if (M->MaterializeAllPermanently(ErrMsg)) {
2810     delete M;
2811     return 0;
2812   }
2813 
2814   // TODO: Restore the use-lists to the in-memory state when the bitcode was
2815   // written.  We must defer until the Module has been fully materialized.
2816 
2817   return M;
2818 }
2819 
2820 std::string llvm::getBitcodeTargetTriple(MemoryBuffer *Buffer,
2821                                          LLVMContext& Context,
2822                                          std::string *ErrMsg) {
2823   BitcodeReader *R = new BitcodeReader(Buffer, Context);
2824   // Don't let the BitcodeReader dtor delete 'Buffer'.
2825   R->setBufferOwned(false);
2826 
2827   std::string Triple("");
2828   if (R->ParseTriple(Triple))
2829     if (ErrMsg)
2830       *ErrMsg = R->getErrorString();
2831 
2832   delete R;
2833   return Triple;
2834 }
2835