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 27 namespace llvm { 28 class MemoryBuffer; 29 class LLVMContext; 30 } 31 32 namespace llvm_2_7 { 33 34 using namespace llvm; 35 36 //===----------------------------------------------------------------------===// 37 // BitcodeReaderValueList Class 38 //===----------------------------------------------------------------------===// 39 40 class BitcodeReaderValueList { 41 std::vector<WeakVH> ValuePtrs; 42 43 /// ResolveConstants - As we resolve forward-referenced constants, we add 44 /// information about them to this vector. This allows us to resolve them in 45 /// bulk instead of resolving each reference at a time. See the code in 46 /// ResolveConstantForwardRefs for more information about this. 47 /// 48 /// The key of this vector is the placeholder constant, the value is the slot 49 /// number that holds the resolved value. 50 typedef std::vector<std::pair<Constant*, unsigned> > ResolveConstantsTy; 51 ResolveConstantsTy ResolveConstants; 52 LLVMContext &Context; 53 public: 54 BitcodeReaderValueList(LLVMContext &C) : Context(C) {} 55 ~BitcodeReaderValueList() { 56 assert(ResolveConstants.empty() && "Constants not resolved?"); 57 } 58 59 // vector compatibility methods 60 unsigned size() const { return ValuePtrs.size(); } 61 void resize(unsigned N) { ValuePtrs.resize(N); } 62 void push_back(Value *V) { 63 ValuePtrs.push_back(V); 64 } 65 66 void clear() { 67 assert(ResolveConstants.empty() && "Constants not resolved?"); 68 ValuePtrs.clear(); 69 } 70 71 Value *operator[](unsigned i) const { 72 assert(i < ValuePtrs.size()); 73 return ValuePtrs[i]; 74 } 75 76 Value *back() const { return ValuePtrs.back(); } 77 void pop_back() { ValuePtrs.pop_back(); } 78 bool empty() const { return ValuePtrs.empty(); } 79 void shrinkTo(unsigned N) { 80 assert(N <= size() && "Invalid shrinkTo request!"); 81 ValuePtrs.resize(N); 82 } 83 84 Constant *getConstantFwdRef(unsigned Idx, Type *Ty); 85 Value *getValueFwdRef(unsigned Idx, Type *Ty); 86 87 void AssignValue(Value *V, unsigned Idx); 88 89 /// ResolveConstantForwardRefs - Once all constants are read, this method bulk 90 /// resolves any forward references. 91 void ResolveConstantForwardRefs(); 92 }; 93 94 95 //===----------------------------------------------------------------------===// 96 // BitcodeReaderMDValueList Class 97 //===----------------------------------------------------------------------===// 98 99 class BitcodeReaderMDValueList { 100 std::vector<WeakVH> MDValuePtrs; 101 102 LLVMContext &Context; 103 public: 104 BitcodeReaderMDValueList(LLVMContext& C) : Context(C) {} 105 106 // vector compatibility methods 107 unsigned size() const { return MDValuePtrs.size(); } 108 void resize(unsigned N) { MDValuePtrs.resize(N); } 109 void push_back(Value *V) { MDValuePtrs.push_back(V); } 110 void clear() { MDValuePtrs.clear(); } 111 Value *back() const { return MDValuePtrs.back(); } 112 void pop_back() { MDValuePtrs.pop_back(); } 113 bool empty() const { return MDValuePtrs.empty(); } 114 115 Value *operator[](unsigned i) const { 116 assert(i < MDValuePtrs.size()); 117 return MDValuePtrs[i]; 118 } 119 120 void shrinkTo(unsigned N) { 121 assert(N <= size() && "Invalid shrinkTo request!"); 122 MDValuePtrs.resize(N); 123 } 124 125 Value *getValueFwdRef(unsigned Idx); 126 void AssignValue(Value *V, unsigned Idx); 127 }; 128 129 class BitcodeReader : public GVMaterializer { 130 LLVMContext &Context; 131 Module *TheModule; 132 MemoryBuffer *Buffer; 133 bool BufferOwned; 134 BitstreamReader StreamFile; 135 BitstreamCursor Stream; 136 137 const char *ErrorString; 138 139 std::vector<Type*> TypeList; 140 BitcodeReaderValueList ValueList; 141 BitcodeReaderMDValueList MDValueList; 142 SmallVector<Instruction *, 64> InstructionList; 143 144 std::vector<std::pair<GlobalVariable*, unsigned> > GlobalInits; 145 std::vector<std::pair<GlobalAlias*, unsigned> > AliasInits; 146 147 /// MAttributes - The set of attributes by index. Index zero in the 148 /// file is for null, and is thus not represented here. As such all indices 149 /// are off by one. 150 std::vector<AttrListPtr> MAttributes; 151 152 /// FunctionBBs - While parsing a function body, this is a list of the basic 153 /// blocks for the function. 154 std::vector<BasicBlock*> FunctionBBs; 155 156 // When reading the module header, this list is populated with functions that 157 // have bodies later in the file. 158 std::vector<Function*> FunctionsWithBodies; 159 160 // When intrinsic functions are encountered which require upgrading they are 161 // stored here with their replacement function. 162 typedef std::vector<std::pair<Function*, Function*> > UpgradedIntrinsicMap; 163 UpgradedIntrinsicMap UpgradedIntrinsics; 164 165 // Map the bitcode's custom MDKind ID to the Module's MDKind ID. 166 DenseMap<unsigned, unsigned> MDKindMap; 167 168 // After the module header has been read, the FunctionsWithBodies list is 169 // reversed. This keeps track of whether we've done this yet. 170 bool HasReversedFunctionsWithBodies; 171 172 /// DeferredFunctionInfo - When function bodies are initially scanned, this 173 /// map contains info about where to find deferred function body in the 174 /// stream. 175 DenseMap<Function*, uint64_t> DeferredFunctionInfo; 176 177 /// BlockAddrFwdRefs - These are blockaddr references to basic blocks. These 178 /// are resolved lazily when functions are loaded. 179 typedef std::pair<unsigned, GlobalVariable*> BlockAddrRefTy; 180 DenseMap<Function*, std::vector<BlockAddrRefTy> > BlockAddrFwdRefs; 181 182 /// LLVM2_7MetadataDetected - True if metadata produced by LLVM 2.7 or 183 /// earlier was detected, in which case we behave slightly differently, 184 /// for compatibility. 185 /// FIXME: Remove in LLVM 3.0. 186 bool LLVM2_7MetadataDetected; 187 188 public: 189 explicit BitcodeReader(MemoryBuffer *buffer, LLVMContext &C) 190 : Context(C), TheModule(0), Buffer(buffer), BufferOwned(false), 191 ErrorString(0), ValueList(C), MDValueList(C), 192 LLVM2_7MetadataDetected(false) { 193 HasReversedFunctionsWithBodies = false; 194 } 195 ~BitcodeReader() { 196 FreeState(); 197 } 198 199 void FreeState(); 200 201 /// setBufferOwned - If this is true, the reader will destroy the MemoryBuffer 202 /// when the reader is destroyed. 203 void setBufferOwned(bool Owned) { BufferOwned = Owned; } 204 205 virtual bool isMaterializable(const GlobalValue *GV) const; 206 virtual bool isDematerializable(const GlobalValue *GV) const; 207 virtual bool Materialize(GlobalValue *GV, std::string *ErrInfo = 0); 208 virtual bool MaterializeModule(Module *M, std::string *ErrInfo = 0); 209 virtual void Dematerialize(GlobalValue *GV); 210 211 bool Error(const char *Str) { 212 ErrorString = Str; 213 return true; 214 } 215 const char *getErrorString() const { return ErrorString; } 216 217 /// @brief Main interface to parsing a bitcode buffer. 218 /// @returns true if an error occurred. 219 bool ParseBitcodeInto(Module *M); 220 221 /// @brief Cheap mechanism to just extract module triple 222 /// @returns true if an error occurred. 223 bool ParseTriple(std::string &Triple); 224 private: 225 Type *getTypeByID(unsigned ID); 226 Type *getTypeByIDOrNull(unsigned ID); 227 Value *getFnValueByID(unsigned ID, Type *Ty) { 228 if (Ty && Ty->isMetadataTy()) 229 return MDValueList.getValueFwdRef(ID); 230 return ValueList.getValueFwdRef(ID, Ty); 231 } 232 BasicBlock *getBasicBlock(unsigned ID) const { 233 if (ID >= FunctionBBs.size()) return 0; // Invalid ID 234 return FunctionBBs[ID]; 235 } 236 AttrListPtr getAttributes(unsigned i) const { 237 if (i-1 < MAttributes.size()) 238 return MAttributes[i-1]; 239 return AttrListPtr(); 240 } 241 242 /// getValueTypePair - Read a value/type pair out of the specified record from 243 /// slot 'Slot'. Increment Slot past the number of slots used in the record. 244 /// Return true on failure. 245 bool getValueTypePair(SmallVector<uint64_t, 64> &Record, unsigned &Slot, 246 unsigned InstNum, Value *&ResVal) { 247 if (Slot == Record.size()) return true; 248 unsigned ValNo = (unsigned)Record[Slot++]; 249 if (ValNo < InstNum) { 250 // If this is not a forward reference, just return the value we already 251 // have. 252 ResVal = getFnValueByID(ValNo, 0); 253 return ResVal == 0; 254 } else if (Slot == Record.size()) { 255 return true; 256 } 257 258 unsigned TypeNo = (unsigned)Record[Slot++]; 259 ResVal = getFnValueByID(ValNo, getTypeByID(TypeNo)); 260 return ResVal == 0; 261 } 262 bool getValue(SmallVector<uint64_t, 64> &Record, unsigned &Slot, 263 Type *Ty, Value *&ResVal) { 264 if (Slot == Record.size()) return true; 265 unsigned ValNo = (unsigned)Record[Slot++]; 266 ResVal = getFnValueByID(ValNo, Ty); 267 return ResVal == 0; 268 } 269 270 271 bool ParseModule(); 272 bool ParseAttributeBlock(); 273 bool ParseTypeTable(); 274 bool ParseOldTypeTable(); // FIXME: Remove in LLVM 3.1 275 bool ParseTypeTableBody(); 276 277 bool ParseOldTypeSymbolTable(); // FIXME: Remove in LLVM 3.1 278 bool ParseValueSymbolTable(); 279 bool ParseConstants(); 280 bool RememberAndSkipFunctionBody(); 281 bool ParseFunctionBody(Function *F); 282 bool ResolveGlobalAndAliasInits(); 283 bool ParseMetadata(); 284 bool ParseMetadataAttachment(); 285 bool ParseModuleTriple(std::string &Triple); 286 }; 287 288 } // End llvm namespace 289 290 #endif 291
