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 "Support/DataTypes.h"
25 struct FunctionInfo; // Defined in ExecutionAnnotations.h
27 // AllocaHolder - Object to track all of the blocks of memory allocated by
28 // alloca. When the function returns, this object is poped off the execution
29 // stack, which causes the dtor to be run, which frees all the alloca'd memory.
32 friend class AllocaHolderHandle;
33 std::vector<void*> Allocations;
36 AllocaHolder() : RefCnt(0) {}
37 void add(void *mem) { Allocations.push_back(mem); }
39 for (unsigned i = 0; i < Allocations.size(); ++i)
44 // AllocaHolderHandle gives AllocaHolder value semantics so we can stick it into
47 class AllocaHolderHandle {
50 AllocaHolderHandle() : H(new AllocaHolder()) { H->RefCnt++; }
51 AllocaHolderHandle(const AllocaHolderHandle &AH) : H(AH.H) { H->RefCnt++; }
52 ~AllocaHolderHandle() { if (--H->RefCnt == 0) delete H; }
54 void add(void *mem) { H->add(mem); }
57 typedef std::vector<GenericValue> ValuePlaneTy;
59 // ExecutionContext struct - This struct represents one stack frame currently
62 struct ExecutionContext {
63 Function *CurFunction;// The currently executing function
64 BasicBlock *CurBB; // The currently executing BB
65 BasicBlock::iterator CurInst; // The next instruction to execute
66 std::map<Value *, GenericValue> Values; // LLVM values used in this invocation
67 std::vector<GenericValue> VarArgs; // Values passed through an ellipsis
68 CallSite Caller; // Holds the call that called subframes.
69 // NULL if main func or debugger invoked fn
70 AllocaHolderHandle Allocas; // Track memory allocated by alloca
73 // Interpreter - This class represents the entirety of the interpreter.
75 class Interpreter : public ExecutionEngine, public InstVisitor<Interpreter> {
76 int ExitCode; // The exit code to be returned by the lli util
79 // The runtime stack of executing code. The top of the stack is the current
81 std::vector<ExecutionContext> ECStack;
83 // AtExitHandlers - List of functions to call when the program exits,
84 // registered with the atexit() library function.
85 std::vector<Function*> AtExitHandlers;
88 Interpreter(Module *M, bool isLittleEndian, bool isLongPointer);
89 inline ~Interpreter() { }
91 /// runAtExitHandlers - Run any functions registered by the
92 /// program's calls to atexit(3), which we intercept and store in
95 void runAtExitHandlers ();
97 /// create - Create an interpreter ExecutionEngine. This can never fail.
99 static ExecutionEngine *create(Module *M);
101 /// run - Start execution with the specified function and arguments.
103 virtual GenericValue run(Function *F,
104 const std::vector<GenericValue> &ArgValues);
106 // Methods used to execute code:
107 // Place a call on the stack
108 void callFunction(Function *F, const std::vector<GenericValue> &ArgVals);
109 void run(); // Execute instructions until nothing left to do
111 // Opcode Implementations
112 void visitReturnInst(ReturnInst &I);
113 void visitBranchInst(BranchInst &I);
114 void visitSwitchInst(SwitchInst &I);
116 void visitBinaryOperator(BinaryOperator &I);
117 void visitAllocationInst(AllocationInst &I);
118 void visitFreeInst(FreeInst &I);
119 void visitLoadInst(LoadInst &I);
120 void visitStoreInst(StoreInst &I);
121 void visitGetElementPtrInst(GetElementPtrInst &I);
123 void visitPHINode(PHINode &PN) { assert(0 && "PHI nodes already handled!"); }
124 void visitCastInst(CastInst &I);
125 void visitCallInst(CallInst &I);
126 void visitShl(ShiftInst &I);
127 void visitShr(ShiftInst &I);
128 void visitVANextInst(VANextInst &I);
129 void visitInstruction(Instruction &I) {
131 assert(0 && "Instruction not interpretable yet!");
134 GenericValue callExternalFunction(Function *F,
135 const std::vector<GenericValue> &ArgVals);
136 void exitCalled(GenericValue GV);
138 void addAtExitHandler(Function *F) {
139 AtExitHandlers.push_back(F);
144 GenericValue executeGEPOperation(Value *Ptr, User::op_iterator I,
145 User::op_iterator E, ExecutionContext &SF);
147 private: // Helper functions
148 // SwitchToNewBasicBlock - Start execution in a new basic block and run any
149 // PHI nodes in the top of the block. This is used for intraprocedural
152 void SwitchToNewBasicBlock(BasicBlock *Dest, ExecutionContext &SF);
154 void *getPointerToFunction(Function *F) { return (void*)F; }
156 void initializeExecutionEngine();
157 void initializeExternalFunctions();
158 GenericValue getOperandValue(Value *V, ExecutionContext &SF);
159 GenericValue executeCastOperation(Value *SrcVal, const Type *Ty,
160 ExecutionContext &SF);
161 void popStackAndReturnValueToCaller(const Type *RetTy, GenericValue Result);