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"
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 int ExitCode; // The exit code to be returned by the lli util
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, bool isLittleEndian, bool isLongPointer,
97 IntrinsicLowering *IL);
100 /// runAtExitHandlers - Run any functions registered by the program's calls to
101 /// atexit(3), which we intercept and store in AtExitHandlers.
103 void runAtExitHandlers();
105 /// create - Create an interpreter ExecutionEngine. This can never fail. The
106 /// specified IntrinsicLowering implementation will be deleted when the
107 /// Interpreter execution engine is destroyed.
109 static ExecutionEngine *create(Module *M, IntrinsicLowering *IL);
111 /// run - Start execution with the specified function and arguments.
113 virtual GenericValue runFunction(Function *F,
114 const std::vector<GenericValue> &ArgValues);
116 /// recompileAndRelinkFunction - For the interpreter, functions are always
119 virtual void *recompileAndRelinkFunction(Function *F) {
120 return getPointerToFunction(F);
123 /// freeMachineCodeForFunction - The interpreter does not generate any code.
125 void freeMachineCodeForFunction(Function *F) { }
127 // Methods used to execute code:
128 // Place a call on the stack
129 void callFunction(Function *F, const std::vector<GenericValue> &ArgVals);
130 void run(); // Execute instructions until nothing left to do
132 // Opcode Implementations
133 void visitReturnInst(ReturnInst &I);
134 void visitBranchInst(BranchInst &I);
135 void visitSwitchInst(SwitchInst &I);
137 void visitBinaryOperator(BinaryOperator &I);
138 void visitAllocationInst(AllocationInst &I);
139 void visitFreeInst(FreeInst &I);
140 void visitLoadInst(LoadInst &I);
141 void visitStoreInst(StoreInst &I);
142 void visitGetElementPtrInst(GetElementPtrInst &I);
143 void visitPHINode(PHINode &PN) { assert(0 && "PHI nodes already handled!"); }
144 void visitCastInst(CastInst &I);
145 void visitSelectInst(SelectInst &I);
148 void visitCallSite(CallSite CS);
149 void visitCallInst(CallInst &I) { visitCallSite (CallSite (&I)); }
150 void visitInvokeInst(InvokeInst &I) { visitCallSite (CallSite (&I)); }
151 void visitUnwindInst(UnwindInst &I);
152 void visitUnreachableInst(UnreachableInst &I);
154 void visitShl(ShiftInst &I);
155 void visitShr(ShiftInst &I);
156 void visitVANextInst(VANextInst &I);
157 void visitVAArgInst(VAArgInst &I);
158 void visitInstruction(Instruction &I) {
160 assert(0 && "Instruction not interpretable yet!");
163 GenericValue callExternalFunction(Function *F,
164 const std::vector<GenericValue> &ArgVals);
165 void exitCalled(GenericValue GV);
167 void addAtExitHandler(Function *F) {
168 AtExitHandlers.push_back(F);
171 GenericValue *getFirstVarArg () {
172 return &(ECStack.back ().VarArgs[0]);
177 GenericValue executeGEPOperation(Value *Ptr, gep_type_iterator I,
178 gep_type_iterator E, ExecutionContext &SF);
180 private: // Helper functions
181 // SwitchToNewBasicBlock - Start execution in a new basic block and run any
182 // PHI nodes in the top of the block. This is used for intraprocedural
185 void SwitchToNewBasicBlock(BasicBlock *Dest, ExecutionContext &SF);
187 void *getPointerToFunction(Function *F) { return (void*)F; }
189 void initializeExecutionEngine();
190 void initializeExternalFunctions();
191 GenericValue getConstantExprValue(ConstantExpr *CE, ExecutionContext &SF);
192 GenericValue getOperandValue(Value *V, ExecutionContext &SF);
193 GenericValue executeCastOperation(Value *SrcVal, const Type *Ty,
194 ExecutionContext &SF);
195 void popStackAndReturnValueToCaller(const Type *RetTy, GenericValue Result);
198 } // End llvm namespace