1 //===-- Interpreter.h ------------------------------------------*- C++ -*--===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This header file defines the interpreter structure
12 //===----------------------------------------------------------------------===//
14 #ifndef LLI_INTERPRETER_H
15 #define LLI_INTERPRETER_H
17 #include "llvm/Function.h"
18 #include "llvm/ExecutionEngine/ExecutionEngine.h"
19 #include "llvm/ExecutionEngine/GenericValue.h"
20 #include "llvm/Support/InstVisitor.h"
21 #include "llvm/Support/CallSite.h"
22 #include "llvm/Target/TargetData.h"
23 #include "llvm/Support/DataTypes.h"
27 class IntrinsicLowering;
29 template<typename T> class generic_gep_type_iterator;
31 typedef generic_gep_type_iterator<User::const_op_iterator> gep_type_iterator;
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.
39 friend class AllocaHolderHandle;
40 std::vector<void*> Allocations;
43 AllocaHolder() : RefCnt(0) {}
44 void add(void *mem) { Allocations.push_back(mem); }
46 for (unsigned i = 0; i < Allocations.size(); ++i)
51 // AllocaHolderHandle gives AllocaHolder value semantics so we can stick it into
54 class AllocaHolderHandle {
57 AllocaHolderHandle() : H(new AllocaHolder()) { H->RefCnt++; }
58 AllocaHolderHandle(const AllocaHolderHandle &AH) : H(AH.H) { H->RefCnt++; }
59 ~AllocaHolderHandle() { if (--H->RefCnt == 0) delete H; }
61 void add(void *mem) { H->add(mem); }
64 typedef std::vector<GenericValue> ValuePlaneTy;
66 // ExecutionContext struct - This struct represents one stack frame currently
69 struct ExecutionContext {
70 Function *CurFunction;// The currently executing function
71 BasicBlock *CurBB; // The currently executing BB
72 BasicBlock::iterator CurInst; // The next instruction to execute
73 std::map<Value *, GenericValue> Values; // LLVM values used in this invocation
74 std::vector<GenericValue> VarArgs; // Values passed through an ellipsis
75 CallSite Caller; // Holds the call that called subframes.
76 // NULL if main func or debugger invoked fn
77 AllocaHolderHandle Allocas; // Track memory allocated by alloca
80 // Interpreter - This class represents the entirety of the interpreter.
82 class Interpreter : public ExecutionEngine, public InstVisitor<Interpreter> {
83 GenericValue ExitValue; // The return value of the called function
85 IntrinsicLowering *IL;
87 // The runtime stack of executing code. The top of the stack is the current
89 std::vector<ExecutionContext> ECStack;
91 // AtExitHandlers - List of functions to call when the program exits,
92 // registered with the atexit() library function.
93 std::vector<Function*> AtExitHandlers;
96 Interpreter(Module *M);
99 /// runAtExitHandlers - Run any functions registered by the program's calls to
100 /// atexit(3), which we intercept and store in AtExitHandlers.
102 void runAtExitHandlers();
104 static void Register() {
108 /// create - Create an interpreter ExecutionEngine. This can never fail.
110 static ExecutionEngine *create(ModuleProvider *M);
112 /// run - Start execution with the specified function and arguments.
114 virtual GenericValue runFunction(Function *F,
115 const std::vector<GenericValue> &ArgValues);
117 /// recompileAndRelinkFunction - For the interpreter, functions are always
120 virtual void *recompileAndRelinkFunction(Function *F) {
121 return getPointerToFunction(F);
124 /// freeMachineCodeForFunction - The interpreter does not generate any code.
126 void freeMachineCodeForFunction(Function *F) { }
128 // Methods used to execute code:
129 // Place a call on the stack
130 void callFunction(Function *F, const std::vector<GenericValue> &ArgVals);
131 void run(); // Execute instructions until nothing left to do
133 // Opcode Implementations
134 void visitReturnInst(ReturnInst &I);
135 void visitBranchInst(BranchInst &I);
136 void visitSwitchInst(SwitchInst &I);
138 void visitBinaryOperator(BinaryOperator &I);
139 void visitICmpInst(ICmpInst &I);
140 void visitFCmpInst(FCmpInst &I);
141 void visitAllocationInst(AllocationInst &I);
142 void visitFreeInst(FreeInst &I);
143 void visitLoadInst(LoadInst &I);
144 void visitStoreInst(StoreInst &I);
145 void visitGetElementPtrInst(GetElementPtrInst &I);
146 void visitPHINode(PHINode &PN) { assert(0 && "PHI nodes already handled!"); }
147 void visitCastInst(CastInst &I);
148 void visitSelectInst(SelectInst &I);
151 void visitCallSite(CallSite CS);
152 void visitCallInst(CallInst &I) { visitCallSite (CallSite (&I)); }
153 void visitInvokeInst(InvokeInst &I) { visitCallSite (CallSite (&I)); }
154 void visitUnwindInst(UnwindInst &I);
155 void visitUnreachableInst(UnreachableInst &I);
157 void visitShl(ShiftInst &I);
158 void visitLShr(ShiftInst &I);
159 void visitAShr(ShiftInst &I);
160 void visitVAArgInst(VAArgInst &I);
161 void visitInstruction(Instruction &I) {
163 assert(0 && "Instruction not interpretable yet!");
166 GenericValue callExternalFunction(Function *F,
167 const std::vector<GenericValue> &ArgVals);
168 void exitCalled(GenericValue GV);
170 void addAtExitHandler(Function *F) {
171 AtExitHandlers.push_back(F);
174 GenericValue *getFirstVarArg () {
175 return &(ECStack.back ().VarArgs[0]);
180 GenericValue executeGEPOperation(Value *Ptr, gep_type_iterator I,
181 gep_type_iterator E, ExecutionContext &SF);
183 private: // Helper functions
184 // SwitchToNewBasicBlock - Start execution in a new basic block and run any
185 // PHI nodes in the top of the block. This is used for intraprocedural
188 void SwitchToNewBasicBlock(BasicBlock *Dest, ExecutionContext &SF);
190 void *getPointerToFunction(Function *F) { return (void*)F; }
192 void initializeExecutionEngine();
193 void initializeExternalFunctions();
194 GenericValue getConstantExprValue(ConstantExpr *CE, ExecutionContext &SF);
195 GenericValue getOperandValue(Value *V, ExecutionContext &SF);
196 GenericValue executeCastOperation(Instruction::CastOps opcode, Value *SrcVal,
197 const Type *Ty, ExecutionContext &SF);
198 void popStackAndReturnValueToCaller(const Type *RetTy, GenericValue Result);
201 } // End llvm namespace