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: 42 AllocaHolder() {} 43 44 // Make this type move-only. 45 AllocaHolder(AllocaHolder &&) = default; 46 AllocaHolder &operator=(AllocaHolder &&RHS) = default; 47 48 ~AllocaHolder() { 49 for (void *Allocation : Allocations) 50 free(Allocation); 51 } 52 53 void add(void *Mem) { Allocations.push_back(Mem); } 54 }; 55 56 typedef std::vector<GenericValue> ValuePlaneTy; 57 58 // ExecutionContext struct - This struct represents one stack frame currently 59 // executing. 60 // 61 struct ExecutionContext { 62 Function *CurFunction;// The currently executing function 63 BasicBlock *CurBB; // The currently executing BB 64 BasicBlock::iterator CurInst; // The next instruction to execute 65 CallSite Caller; // Holds the call that called subframes. 66 // NULL if main func or debugger invoked fn 67 std::map<Value *, GenericValue> Values; // LLVM values used in this invocation 68 std::vector<GenericValue> VarArgs; // Values passed through an ellipsis 69 AllocaHolder Allocas; // Track memory allocated by alloca 70 71 ExecutionContext() : CurFunction(nullptr), CurBB(nullptr), CurInst(nullptr) {} 72 }; 73 74 // Interpreter - This class represents the entirety of the interpreter. 75 // 76 class Interpreter : public ExecutionEngine, public InstVisitor<Interpreter> { 77 GenericValue ExitValue; // The return value of the called function 78 IntrinsicLowering *IL; 79 80 // The runtime stack of executing code. The top of the stack is the current 81 // function record. 82 std::vector<ExecutionContext> ECStack; 83 84 // AtExitHandlers - List of functions to call when the program exits, 85 // registered with the atexit() library function. 86 std::vector<Function*> AtExitHandlers; 87 88 public: 89 explicit Interpreter(std::unique_ptr<Module> M); 90 ~Interpreter() override; 91 92 /// runAtExitHandlers - Run any functions registered by the program's calls to 93 /// atexit(3), which we intercept and store in AtExitHandlers. 94 /// 95 void runAtExitHandlers(); 96 97 static void Register() { 98 InterpCtor = create; 99 } 100 101 /// Create an interpreter ExecutionEngine. 102 /// 103 static ExecutionEngine *create(std::unique_ptr<Module> M, 104 std::string *ErrorStr = nullptr); 105 106 /// run - Start execution with the specified function and arguments. 107 /// 108 GenericValue runFunction(Function *F, 109 ArrayRef<GenericValue> ArgValues) override; 110 111 void *getPointerToNamedFunction(StringRef Name, 112 bool AbortOnFailure = true) override { 113 // FIXME: not implemented. 114 return nullptr; 115 } 116 117 // Methods used to execute code: 118 // Place a call on the stack 119 void callFunction(Function *F, ArrayRef<GenericValue> ArgVals); 120 void run(); // Execute instructions until nothing left to do 121 122 // Opcode Implementations 123 void visitReturnInst(ReturnInst &I); 124 void visitBranchInst(BranchInst &I); 125 void visitSwitchInst(SwitchInst &I); 126 void visitIndirectBrInst(IndirectBrInst &I); 127 128 void visitBinaryOperator(BinaryOperator &I); 129 void visitICmpInst(ICmpInst &I); 130 void visitFCmpInst(FCmpInst &I); 131 void visitAllocaInst(AllocaInst &I); 132 void visitLoadInst(LoadInst &I); 133 void visitStoreInst(StoreInst &I); 134 void visitGetElementPtrInst(GetElementPtrInst &I); 135 void visitPHINode(PHINode &PN) { 136 llvm_unreachable("PHI nodes already handled!"); 137 } 138 void visitTruncInst(TruncInst &I); 139 void visitZExtInst(ZExtInst &I); 140 void visitSExtInst(SExtInst &I); 141 void visitFPTruncInst(FPTruncInst &I); 142 void visitFPExtInst(FPExtInst &I); 143 void visitUIToFPInst(UIToFPInst &I); 144 void visitSIToFPInst(SIToFPInst &I); 145 void visitFPToUIInst(FPToUIInst &I); 146 void visitFPToSIInst(FPToSIInst &I); 147 void visitPtrToIntInst(PtrToIntInst &I); 148 void visitIntToPtrInst(IntToPtrInst &I); 149 void visitBitCastInst(BitCastInst &I); 150 void visitSelectInst(SelectInst &I); 151 152 153 void visitCallSite(CallSite CS); 154 void visitCallInst(CallInst &I) { visitCallSite (CallSite (&I)); } 155 void visitInvokeInst(InvokeInst &I) { visitCallSite (CallSite (&I)); } 156 void visitUnreachableInst(UnreachableInst &I); 157 158 void visitShl(BinaryOperator &I); 159 void visitLShr(BinaryOperator &I); 160 void visitAShr(BinaryOperator &I); 161 162 void visitVAArgInst(VAArgInst &I); 163 void visitExtractElementInst(ExtractElementInst &I); 164 void visitInsertElementInst(InsertElementInst &I); 165 void visitShuffleVectorInst(ShuffleVectorInst &I); 166 167 void visitExtractValueInst(ExtractValueInst &I); 168 void visitInsertValueInst(InsertValueInst &I); 169 170 void visitInstruction(Instruction &I) { 171 errs() << I << "\n"; 172 llvm_unreachable("Instruction not interpretable yet!"); 173 } 174 175 GenericValue callExternalFunction(Function *F, 176 ArrayRef<GenericValue> ArgVals); 177 void exitCalled(GenericValue GV); 178 179 void addAtExitHandler(Function *F) { 180 AtExitHandlers.push_back(F); 181 } 182 183 GenericValue *getFirstVarArg () { 184 return &(ECStack.back ().VarArgs[0]); 185 } 186 187 private: // Helper functions 188 GenericValue executeGEPOperation(Value *Ptr, gep_type_iterator I, 189 gep_type_iterator E, ExecutionContext &SF); 190 191 // SwitchToNewBasicBlock - Start execution in a new basic block and run any 192 // PHI nodes in the top of the block. This is used for intraprocedural 193 // control flow. 194 // 195 void SwitchToNewBasicBlock(BasicBlock *Dest, ExecutionContext &SF); 196 197 void *getPointerToFunction(Function *F) override { return (void*)F; } 198 199 void initializeExecutionEngine() { } 200 void initializeExternalFunctions(); 201 GenericValue getConstantExprValue(ConstantExpr *CE, ExecutionContext &SF); 202 GenericValue getOperandValue(Value *V, ExecutionContext &SF); 203 GenericValue executeTruncInst(Value *SrcVal, Type *DstTy, 204 ExecutionContext &SF); 205 GenericValue executeSExtInst(Value *SrcVal, Type *DstTy, 206 ExecutionContext &SF); 207 GenericValue executeZExtInst(Value *SrcVal, Type *DstTy, 208 ExecutionContext &SF); 209 GenericValue executeFPTruncInst(Value *SrcVal, Type *DstTy, 210 ExecutionContext &SF); 211 GenericValue executeFPExtInst(Value *SrcVal, Type *DstTy, 212 ExecutionContext &SF); 213 GenericValue executeFPToUIInst(Value *SrcVal, Type *DstTy, 214 ExecutionContext &SF); 215 GenericValue executeFPToSIInst(Value *SrcVal, Type *DstTy, 216 ExecutionContext &SF); 217 GenericValue executeUIToFPInst(Value *SrcVal, Type *DstTy, 218 ExecutionContext &SF); 219 GenericValue executeSIToFPInst(Value *SrcVal, Type *DstTy, 220 ExecutionContext &SF); 221 GenericValue executePtrToIntInst(Value *SrcVal, Type *DstTy, 222 ExecutionContext &SF); 223 GenericValue executeIntToPtrInst(Value *SrcVal, Type *DstTy, 224 ExecutionContext &SF); 225 GenericValue executeBitCastInst(Value *SrcVal, Type *DstTy, 226 ExecutionContext &SF); 227 GenericValue executeCastOperation(Instruction::CastOps opcode, Value *SrcVal, 228 Type *Ty, ExecutionContext &SF); 229 void popStackAndReturnValueToCaller(Type *RetTy, GenericValue Result); 230 231 }; 232 233 } // End llvm namespace 234 235 #endif 236
