1 //===-- Interpreter.h ------------------------------------------*- 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 file defines the interpreter structure 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_LIB_EXECUTIONENGINE_INTERPRETER_INTERPRETER_H 15 #define LLVM_LIB_EXECUTIONENGINE_INTERPRETER_INTERPRETER_H 16 17 #include "llvm/ExecutionEngine/ExecutionEngine.h" 18 #include "llvm/ExecutionEngine/GenericValue.h" 19 #include "llvm/IR/CallSite.h" 20 #include "llvm/IR/DataLayout.h" 21 #include "llvm/IR/Function.h" 22 #include "llvm/IR/InstVisitor.h" 23 #include "llvm/Support/DataTypes.h" 24 #include "llvm/Support/ErrorHandling.h" 25 #include "llvm/Support/raw_ostream.h" 26 namespace llvm { 27 28 class IntrinsicLowering; 29 template<typename T> class generic_gep_type_iterator; 30 class ConstantExpr; 31 typedef generic_gep_type_iterator<User::const_op_iterator> gep_type_iterator; 32 33 34 // AllocaHolder - Object to track all of the blocks of memory allocated by 35 // alloca. When the function returns, this object is popped off the execution 36 // stack, which causes the dtor to be run, which frees all the alloca'd memory. 37 // 38 class AllocaHolder { 39 std::vector<void *> Allocations; 40 41 public: AllocaHolder()42 AllocaHolder() {} 43 44 // Make this type move-only. Define explicit move special members for MSVC. AllocaHolder(AllocaHolder && RHS)45 AllocaHolder(AllocaHolder &&RHS) : Allocations(std::move(RHS.Allocations)) {} 46 AllocaHolder &operator=(AllocaHolder &&RHS) { 47 Allocations = std::move(RHS.Allocations); 48 return *this; 49 } 50 ~AllocaHolder()51 ~AllocaHolder() { 52 for (void *Allocation : Allocations) 53 free(Allocation); 54 } 55 add(void * Mem)56 void add(void *Mem) { Allocations.push_back(Mem); } 57 }; 58 59 typedef std::vector<GenericValue> ValuePlaneTy; 60 61 // ExecutionContext struct - This struct represents one stack frame currently 62 // executing. 63 // 64 struct ExecutionContext { 65 Function *CurFunction;// The currently executing function 66 BasicBlock *CurBB; // The currently executing BB 67 BasicBlock::iterator CurInst; // The next instruction to execute 68 CallSite Caller; // Holds the call that called subframes. 69 // NULL if main func or debugger invoked fn 70 std::map<Value *, GenericValue> Values; // LLVM values used in this invocation 71 std::vector<GenericValue> VarArgs; // Values passed through an ellipsis 72 AllocaHolder Allocas; // Track memory allocated by alloca 73 ExecutionContextExecutionContext74 ExecutionContext() : CurFunction(nullptr), CurBB(nullptr), CurInst(nullptr) {} 75 ExecutionContextExecutionContext76 ExecutionContext(ExecutionContext &&O) 77 : CurFunction(O.CurFunction), CurBB(O.CurBB), CurInst(O.CurInst), 78 Caller(O.Caller), Values(std::move(O.Values)), 79 VarArgs(std::move(O.VarArgs)), Allocas(std::move(O.Allocas)) {} 80 81 ExecutionContext &operator=(ExecutionContext &&O) { 82 CurFunction = O.CurFunction; 83 CurBB = O.CurBB; 84 CurInst = O.CurInst; 85 Caller = O.Caller; 86 Values = std::move(O.Values); 87 VarArgs = std::move(O.VarArgs); 88 Allocas = std::move(O.Allocas); 89 return *this; 90 } 91 }; 92 93 // Interpreter - This class represents the entirety of the interpreter. 94 // 95 class Interpreter : public ExecutionEngine, public InstVisitor<Interpreter> { 96 GenericValue ExitValue; // The return value of the called function 97 IntrinsicLowering *IL; 98 99 // The runtime stack of executing code. The top of the stack is the current 100 // function record. 101 std::vector<ExecutionContext> ECStack; 102 103 // AtExitHandlers - List of functions to call when the program exits, 104 // registered with the atexit() library function. 105 std::vector<Function*> AtExitHandlers; 106 107 public: 108 explicit Interpreter(std::unique_ptr<Module> M); 109 ~Interpreter() override; 110 111 /// runAtExitHandlers - Run any functions registered by the program's calls to 112 /// atexit(3), which we intercept and store in AtExitHandlers. 113 /// 114 void runAtExitHandlers(); 115 Register()116 static void Register() { 117 InterpCtor = create; 118 } 119 120 /// Create an interpreter ExecutionEngine. 121 /// 122 static ExecutionEngine *create(std::unique_ptr<Module> M, 123 std::string *ErrorStr = nullptr); 124 125 /// run - Start execution with the specified function and arguments. 126 /// 127 GenericValue runFunction(Function *F, 128 ArrayRef<GenericValue> ArgValues) override; 129 130 void *getPointerToNamedFunction(StringRef Name, 131 bool AbortOnFailure = true) override { 132 // FIXME: not implemented. 133 return nullptr; 134 } 135 136 // Methods used to execute code: 137 // Place a call on the stack 138 void callFunction(Function *F, ArrayRef<GenericValue> ArgVals); 139 void run(); // Execute instructions until nothing left to do 140 141 // Opcode Implementations 142 void visitReturnInst(ReturnInst &I); 143 void visitBranchInst(BranchInst &I); 144 void visitSwitchInst(SwitchInst &I); 145 void visitIndirectBrInst(IndirectBrInst &I); 146 147 void visitBinaryOperator(BinaryOperator &I); 148 void visitICmpInst(ICmpInst &I); 149 void visitFCmpInst(FCmpInst &I); 150 void visitAllocaInst(AllocaInst &I); 151 void visitLoadInst(LoadInst &I); 152 void visitStoreInst(StoreInst &I); 153 void visitGetElementPtrInst(GetElementPtrInst &I); visitPHINode(PHINode & PN)154 void visitPHINode(PHINode &PN) { 155 llvm_unreachable("PHI nodes already handled!"); 156 } 157 void visitTruncInst(TruncInst &I); 158 void visitZExtInst(ZExtInst &I); 159 void visitSExtInst(SExtInst &I); 160 void visitFPTruncInst(FPTruncInst &I); 161 void visitFPExtInst(FPExtInst &I); 162 void visitUIToFPInst(UIToFPInst &I); 163 void visitSIToFPInst(SIToFPInst &I); 164 void visitFPToUIInst(FPToUIInst &I); 165 void visitFPToSIInst(FPToSIInst &I); 166 void visitPtrToIntInst(PtrToIntInst &I); 167 void visitIntToPtrInst(IntToPtrInst &I); 168 void visitBitCastInst(BitCastInst &I); 169 void visitSelectInst(SelectInst &I); 170 171 172 void visitCallSite(CallSite CS); visitCallInst(CallInst & I)173 void visitCallInst(CallInst &I) { visitCallSite (CallSite (&I)); } visitInvokeInst(InvokeInst & I)174 void visitInvokeInst(InvokeInst &I) { visitCallSite (CallSite (&I)); } 175 void visitUnreachableInst(UnreachableInst &I); 176 177 void visitShl(BinaryOperator &I); 178 void visitLShr(BinaryOperator &I); 179 void visitAShr(BinaryOperator &I); 180 181 void visitVAArgInst(VAArgInst &I); 182 void visitExtractElementInst(ExtractElementInst &I); 183 void visitInsertElementInst(InsertElementInst &I); 184 void visitShuffleVectorInst(ShuffleVectorInst &I); 185 186 void visitExtractValueInst(ExtractValueInst &I); 187 void visitInsertValueInst(InsertValueInst &I); 188 visitInstruction(Instruction & I)189 void visitInstruction(Instruction &I) { 190 errs() << I << "\n"; 191 llvm_unreachable("Instruction not interpretable yet!"); 192 } 193 194 GenericValue callExternalFunction(Function *F, 195 ArrayRef<GenericValue> ArgVals); 196 void exitCalled(GenericValue GV); 197 addAtExitHandler(Function * F)198 void addAtExitHandler(Function *F) { 199 AtExitHandlers.push_back(F); 200 } 201 getFirstVarArg()202 GenericValue *getFirstVarArg () { 203 return &(ECStack.back ().VarArgs[0]); 204 } 205 206 private: // Helper functions 207 GenericValue executeGEPOperation(Value *Ptr, gep_type_iterator I, 208 gep_type_iterator E, ExecutionContext &SF); 209 210 // SwitchToNewBasicBlock - Start execution in a new basic block and run any 211 // PHI nodes in the top of the block. This is used for intraprocedural 212 // control flow. 213 // 214 void SwitchToNewBasicBlock(BasicBlock *Dest, ExecutionContext &SF); 215 getPointerToFunction(Function * F)216 void *getPointerToFunction(Function *F) override { return (void*)F; } 217 initializeExecutionEngine()218 void initializeExecutionEngine() { } 219 void initializeExternalFunctions(); 220 GenericValue getConstantExprValue(ConstantExpr *CE, ExecutionContext &SF); 221 GenericValue getOperandValue(Value *V, ExecutionContext &SF); 222 GenericValue executeTruncInst(Value *SrcVal, Type *DstTy, 223 ExecutionContext &SF); 224 GenericValue executeSExtInst(Value *SrcVal, Type *DstTy, 225 ExecutionContext &SF); 226 GenericValue executeZExtInst(Value *SrcVal, Type *DstTy, 227 ExecutionContext &SF); 228 GenericValue executeFPTruncInst(Value *SrcVal, Type *DstTy, 229 ExecutionContext &SF); 230 GenericValue executeFPExtInst(Value *SrcVal, Type *DstTy, 231 ExecutionContext &SF); 232 GenericValue executeFPToUIInst(Value *SrcVal, Type *DstTy, 233 ExecutionContext &SF); 234 GenericValue executeFPToSIInst(Value *SrcVal, Type *DstTy, 235 ExecutionContext &SF); 236 GenericValue executeUIToFPInst(Value *SrcVal, Type *DstTy, 237 ExecutionContext &SF); 238 GenericValue executeSIToFPInst(Value *SrcVal, Type *DstTy, 239 ExecutionContext &SF); 240 GenericValue executePtrToIntInst(Value *SrcVal, Type *DstTy, 241 ExecutionContext &SF); 242 GenericValue executeIntToPtrInst(Value *SrcVal, Type *DstTy, 243 ExecutionContext &SF); 244 GenericValue executeBitCastInst(Value *SrcVal, Type *DstTy, 245 ExecutionContext &SF); 246 GenericValue executeCastOperation(Instruction::CastOps opcode, Value *SrcVal, 247 Type *Ty, ExecutionContext &SF); 248 void popStackAndReturnValueToCaller(Type *RetTy, GenericValue Result); 249 250 }; 251 252 } // End llvm namespace 253 254 #endif 255