BitcodeReader.h revision f0356fe140af1a30587b9a86bcfb1b2c51b8ce20
1//===- BitcodeReader.h - Internal BitcodeReader impl ------------*- C++ -*-===// 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#ifndef BITCODE_READER_H 15#define BITCODE_READER_H 16 17#include "llvm/GVMaterializer.h" 18#include "llvm/Attributes.h" 19#include "llvm/Type.h" 20#include "llvm/OperandTraits.h" 21#include "llvm/Bitcode/BitstreamReader.h" 22#include "llvm/Bitcode/LLVMBitCodes.h" 23#include "llvm/Support/ValueHandle.h" 24#include "llvm/ADT/DenseMap.h" 25#include <vector> 26 27namespace llvm { 28 class MemoryBuffer; 29 class LLVMContext; 30 31//===----------------------------------------------------------------------===// 32// BitcodeReaderValueList Class 33//===----------------------------------------------------------------------===// 34 35class BitcodeReaderValueList { 36 std::vector<WeakVH> ValuePtrs; 37 38 /// ResolveConstants - As we resolve forward-referenced constants, we add 39 /// information about them to this vector. This allows us to resolve them in 40 /// bulk instead of resolving each reference at a time. See the code in 41 /// ResolveConstantForwardRefs for more information about this. 42 /// 43 /// The key of this vector is the placeholder constant, the value is the slot 44 /// number that holds the resolved value. 45 typedef std::vector<std::pair<Constant*, unsigned> > ResolveConstantsTy; 46 ResolveConstantsTy ResolveConstants; 47 LLVMContext& Context; 48public: 49 BitcodeReaderValueList(LLVMContext& C) : Context(C) {} 50 ~BitcodeReaderValueList() { 51 assert(ResolveConstants.empty() && "Constants not resolved?"); 52 } 53 54 // vector compatibility methods 55 unsigned size() const { return ValuePtrs.size(); } 56 void resize(unsigned N) { ValuePtrs.resize(N); } 57 void push_back(Value *V) { 58 ValuePtrs.push_back(V); 59 } 60 61 void clear() { 62 assert(ResolveConstants.empty() && "Constants not resolved?"); 63 ValuePtrs.clear(); 64 } 65 66 Value *operator[](unsigned i) const { 67 assert(i < ValuePtrs.size()); 68 return ValuePtrs[i]; 69 } 70 71 Value *back() const { return ValuePtrs.back(); } 72 void pop_back() { ValuePtrs.pop_back(); } 73 bool empty() const { return ValuePtrs.empty(); } 74 void shrinkTo(unsigned N) { 75 assert(N <= size() && "Invalid shrinkTo request!"); 76 ValuePtrs.resize(N); 77 } 78 79 Constant *getConstantFwdRef(unsigned Idx, const Type *Ty); 80 Value *getValueFwdRef(unsigned Idx, const Type *Ty); 81 82 void AssignValue(Value *V, unsigned Idx); 83 84 /// ResolveConstantForwardRefs - Once all constants are read, this method bulk 85 /// resolves any forward references. 86 void ResolveConstantForwardRefs(); 87}; 88 89 90//===----------------------------------------------------------------------===// 91// BitcodeReaderMDValueList Class 92//===----------------------------------------------------------------------===// 93 94class BitcodeReaderMDValueList { 95 std::vector<WeakVH> MDValuePtrs; 96 97 LLVMContext &Context; 98public: 99 BitcodeReaderMDValueList(LLVMContext& C) : Context(C) {} 100 101 // vector compatibility methods 102 unsigned size() const { return MDValuePtrs.size(); } 103 void resize(unsigned N) { MDValuePtrs.resize(N); } 104 void push_back(Value *V) { MDValuePtrs.push_back(V); } 105 void clear() { MDValuePtrs.clear(); } 106 Value *back() const { return MDValuePtrs.back(); } 107 void pop_back() { MDValuePtrs.pop_back(); } 108 bool empty() const { return MDValuePtrs.empty(); } 109 110 Value *operator[](unsigned i) const { 111 assert(i < MDValuePtrs.size()); 112 return MDValuePtrs[i]; 113 } 114 115 void shrinkTo(unsigned N) { 116 assert(N <= size() && "Invalid shrinkTo request!"); 117 MDValuePtrs.resize(N); 118 } 119 120 Value *getValueFwdRef(unsigned Idx); 121 void AssignValue(Value *V, unsigned Idx); 122}; 123 124class BitcodeReader : public GVMaterializer { 125 LLVMContext &Context; 126 Module *TheModule; 127 MemoryBuffer *Buffer; 128 bool BufferOwned; 129 BitstreamReader StreamFile; 130 BitstreamCursor Stream; 131 132 const char *ErrorString; 133 134 std::vector<PATypeHolder> TypeList; 135 BitcodeReaderValueList ValueList; 136 BitcodeReaderMDValueList MDValueList; 137 SmallVector<Instruction *, 64> InstructionList; 138 139 std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits; 140 std::vector<std::pair<GlobalAlias*, unsigned> > AliasInits; 141 142 /// MAttributes - The set of attributes by index. Index zero in the 143 /// file is for null, and is thus not represented here. As such all indices 144 /// are off by one. 145 std::vector<AttrListPtr> MAttributes; 146 147 /// FunctionBBs - While parsing a function body, this is a list of the basic 148 /// blocks for the function. 149 std::vector<BasicBlock*> FunctionBBs; 150 151 // When reading the module header, this list is populated with functions that 152 // have bodies later in the file. 153 std::vector<Function*> FunctionsWithBodies; 154 155 // When intrinsic functions are encountered which require upgrading they are 156 // stored here with their replacement function. 157 typedef std::vector<std::pair<Function*, Function*> > UpgradedIntrinsicMap; 158 UpgradedIntrinsicMap UpgradedIntrinsics; 159 160 // After the module header has been read, the FunctionsWithBodies list is 161 // reversed. This keeps track of whether we've done this yet. 162 bool HasReversedFunctionsWithBodies; 163 164 /// DeferredFunctionInfo - When function bodies are initially scanned, this 165 /// map contains info about where to find deferred function body in the 166 /// stream. 167 DenseMap<Function*, uint64_t> DeferredFunctionInfo; 168 169 /// BlockAddrFwdRefs - These are blockaddr references to basic blocks. These 170 /// are resolved lazily when functions are loaded. 171 typedef std::pair<unsigned, GlobalVariable*> BlockAddrRefTy; 172 DenseMap<Function*, std::vector<BlockAddrRefTy> > BlockAddrFwdRefs; 173 174public: 175 explicit BitcodeReader(MemoryBuffer *buffer, LLVMContext &C) 176 : Context(C), TheModule(0), Buffer(buffer), BufferOwned(false), 177 ErrorString(0), ValueList(C), MDValueList(C) { 178 HasReversedFunctionsWithBodies = false; 179 } 180 ~BitcodeReader() { 181 FreeState(); 182 } 183 184 void FreeState(); 185 186 /// setBufferOwned - If this is true, the reader will destroy the MemoryBuffer 187 /// when the reader is destroyed. 188 void setBufferOwned(bool Owned) { BufferOwned = Owned; } 189 190 virtual bool isMaterializable(const GlobalValue *GV) const; 191 virtual bool isDematerializable(const GlobalValue *GV) const; 192 virtual bool Materialize(GlobalValue *GV, std::string *ErrInfo = 0); 193 virtual bool MaterializeModule(Module *M, std::string *ErrInfo = 0); 194 virtual void Dematerialize(GlobalValue *GV); 195 196 bool Error(const char *Str) { 197 ErrorString = Str; 198 return true; 199 } 200 const char *getErrorString() const { return ErrorString; } 201 202 /// @brief Main interface to parsing a bitcode buffer. 203 /// @returns true if an error occurred. 204 bool ParseBitcodeInto(Module *M); 205private: 206 const Type *getTypeByID(unsigned ID, bool isTypeTable = false); 207 Value *getFnValueByID(unsigned ID, const Type *Ty) { 208 if (Ty == Type::getMetadataTy(Context)) 209 return MDValueList.getValueFwdRef(ID); 210 else 211 return ValueList.getValueFwdRef(ID, Ty); 212 } 213 BasicBlock *getBasicBlock(unsigned ID) const { 214 if (ID >= FunctionBBs.size()) return 0; // Invalid ID 215 return FunctionBBs[ID]; 216 } 217 AttrListPtr getAttributes(unsigned i) const { 218 if (i-1 < MAttributes.size()) 219 return MAttributes[i-1]; 220 return AttrListPtr(); 221 } 222 223 /// getValueTypePair - Read a value/type pair out of the specified record from 224 /// slot 'Slot'. Increment Slot past the number of slots used in the record. 225 /// Return true on failure. 226 bool getValueTypePair(SmallVector<uint64_t, 64> &Record, unsigned &Slot, 227 unsigned InstNum, Value *&ResVal) { 228 if (Slot == Record.size()) return true; 229 unsigned ValNo = (unsigned)Record[Slot++]; 230 if (ValNo < InstNum) { 231 // If this is not a forward reference, just return the value we already 232 // have. 233 ResVal = getFnValueByID(ValNo, 0); 234 return ResVal == 0; 235 } else if (Slot == Record.size()) { 236 return true; 237 } 238 239 unsigned TypeNo = (unsigned)Record[Slot++]; 240 ResVal = getFnValueByID(ValNo, getTypeByID(TypeNo)); 241 return ResVal == 0; 242 } 243 bool getValue(SmallVector<uint64_t, 64> &Record, unsigned &Slot, 244 const Type *Ty, Value *&ResVal) { 245 if (Slot == Record.size()) return true; 246 unsigned ValNo = (unsigned)Record[Slot++]; 247 ResVal = getFnValueByID(ValNo, Ty); 248 return ResVal == 0; 249 } 250 251 252 bool ParseModule(); 253 bool ParseAttributeBlock(); 254 bool ParseTypeTable(); 255 bool ParseTypeSymbolTable(); 256 bool ParseValueSymbolTable(); 257 bool ParseConstants(); 258 bool RememberAndSkipFunctionBody(); 259 bool ParseFunctionBody(Function *F); 260 bool ResolveGlobalAndAliasInits(); 261 bool ParseMetadata(); 262 bool ParseMetadataAttachment(); 263}; 264 265} // End llvm namespace 266 267#endif 268