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//===-- Interpreter.h ------------------------------------------*- C++ -*--===//
// The LLVM Compiler Infrastructure
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
// This header file defines the interpreter structure
#include "llvm/Function.h"
#include "llvm/ExecutionEngine/ExecutionEngine.h"
#include "llvm/ExecutionEngine/GenericValue.h"
#include "llvm/ADT/APInt.h"
#include "llvm/Support/InstVisitor.h"
#include "llvm/Support/CallSite.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Support/DataTypes.h"
namespace llvm {
class IntrinsicLowering;
struct FunctionInfo;
template<typename T> class generic_gep_type_iterator;
class ConstantExpr;
typedef generic_gep_type_iterator<User::const_op_iterator> gep_type_iterator;
// AllocaHolder - Object to track all of the blocks of memory allocated by
// alloca. When the function returns, this object is popped off the execution
// stack, which causes the dtor to be run, which frees all the alloca'd memory.
class AllocaHolder {
friend class AllocaHolderHandle;
std::vector<void*> Allocations;
unsigned RefCnt;
AllocaHolder() : RefCnt(0) {}
void add(void *mem) { Allocations.push_back(mem); }
~AllocaHolder() {
for (unsigned i = 0; i < Allocations.size(); ++i)
// AllocaHolderHandle gives AllocaHolder value semantics so we can stick it into
// a vector...
class AllocaHolderHandle {
AllocaHolder *H;
AllocaHolderHandle() : H(new AllocaHolder()) { H->RefCnt++; }
AllocaHolderHandle(const AllocaHolderHandle &AH) : H(AH.H) { H->RefCnt++; }
~AllocaHolderHandle() { if (--H->RefCnt == 0) delete H; }
void add(void *mem) { H->add(mem); }
typedef std::vector<GenericValue> ValuePlaneTy;
// ExecutionContext struct - This struct represents one stack frame currently
// executing.
struct ExecutionContext {
Function *CurFunction;// The currently executing function
BasicBlock *CurBB; // The currently executing BB
BasicBlock::iterator CurInst; // The next instruction to execute
std::map<Value *, GenericValue> Values; // LLVM values used in this invocation
std::vector<GenericValue> VarArgs; // Values passed through an ellipsis
CallSite Caller; // Holds the call that called subframes.
// NULL if main func or debugger invoked fn
AllocaHolderHandle Allocas; // Track memory allocated by alloca
// Interpreter - This class represents the entirety of the interpreter.
class Interpreter : public ExecutionEngine, public InstVisitor<Interpreter> {
GenericValue ExitValue; // The return value of the called function
TargetData TD;
IntrinsicLowering *IL;
// The runtime stack of executing code. The top of the stack is the current
// function record.
std::vector<ExecutionContext> ECStack;
// AtExitHandlers - List of functions to call when the program exits,
// registered with the atexit() library function.
std::vector<Function*> AtExitHandlers;
explicit Interpreter(Module *M);
/// runAtExitHandlers - Run any functions registered by the program's calls to
/// atexit(3), which we intercept and store in AtExitHandlers.
void runAtExitHandlers();
static void Register() {
InterpCtor = create;
/// create - Create an interpreter ExecutionEngine. This can never fail.
static ExecutionEngine *create(ModuleProvider *M, std::string *ErrorStr = 0);
/// run - Start execution with the specified function and arguments.
virtual GenericValue runFunction(Function *F,
const std::vector<GenericValue> &ArgValues);
/// recompileAndRelinkFunction - For the interpreter, functions are always
/// up-to-date.
virtual void *recompileAndRelinkFunction(Function *F) {
return getPointerToFunction(F);
/// freeMachineCodeForFunction - The interpreter does not generate any code.
void freeMachineCodeForFunction(Function *F) { }
// Methods used to execute code:
// Place a call on the stack
void callFunction(Function *F, const std::vector<GenericValue> &ArgVals);
void run(); // Execute instructions until nothing left to do
// Opcode Implementations
void visitReturnInst(ReturnInst &I);
void visitBranchInst(BranchInst &I);
void visitSwitchInst(SwitchInst &I);
void visitBinaryOperator(BinaryOperator &I);
void visitICmpInst(ICmpInst &I);
void visitFCmpInst(FCmpInst &I);
void visitAllocationInst(AllocationInst &I);
void visitFreeInst(FreeInst &I);
void visitLoadInst(LoadInst &I);
void visitStoreInst(StoreInst &I);
void visitGetElementPtrInst(GetElementPtrInst &I);
void visitPHINode(PHINode &PN) { assert(0 && "PHI nodes already handled!"); }
void visitTruncInst(TruncInst &I);
void visitZExtInst(ZExtInst &I);
void visitSExtInst(SExtInst &I);
void visitFPTruncInst(FPTruncInst &I);
void visitFPExtInst(FPExtInst &I);
void visitUIToFPInst(UIToFPInst &I);
void visitSIToFPInst(SIToFPInst &I);
void visitFPToUIInst(FPToUIInst &I);
void visitFPToSIInst(FPToSIInst &I);
void visitPtrToIntInst(PtrToIntInst &I);
void visitIntToPtrInst(IntToPtrInst &I);
void visitBitCastInst(BitCastInst &I);
void visitSelectInst(SelectInst &I);
void visitCallSite(CallSite CS);
void visitCallInst(CallInst &I) { visitCallSite (CallSite (&I)); }
void visitInvokeInst(InvokeInst &I) { visitCallSite (CallSite (&I)); }
void visitUnwindInst(UnwindInst &I);
void visitUnreachableInst(UnreachableInst &I);
void visitShl(BinaryOperator &I);
void visitLShr(BinaryOperator &I);
void visitAShr(BinaryOperator &I);
void visitVAArgInst(VAArgInst &I);
void visitInstruction(Instruction &I) {
cerr << I;
assert(0 && "Instruction not interpretable yet!");
GenericValue callExternalFunction(Function *F,
const std::vector<GenericValue> &ArgVals);
void exitCalled(GenericValue GV);
void addAtExitHandler(Function *F) {
GenericValue *getFirstVarArg () {
return &(ECStack.back ().VarArgs[0]);
//FIXME: private:
GenericValue executeGEPOperation(Value *Ptr, gep_type_iterator I,
gep_type_iterator E, ExecutionContext &SF);
private: // Helper functions
// SwitchToNewBasicBlock - Start execution in a new basic block and run any
// PHI nodes in the top of the block. This is used for intraprocedural
// control flow.
void SwitchToNewBasicBlock(BasicBlock *Dest, ExecutionContext &SF);
void *getPointerToFunction(Function *F) { return (void*)F; }
void initializeExecutionEngine();
void initializeExternalFunctions();
GenericValue getConstantExprValue(ConstantExpr *CE, ExecutionContext &SF);
GenericValue getOperandValue(Value *V, ExecutionContext &SF);
GenericValue executeTruncInst(Value *SrcVal, const Type *DstTy,
ExecutionContext &SF);
GenericValue executeSExtInst(Value *SrcVal, const Type *DstTy,
ExecutionContext &SF);
GenericValue executeZExtInst(Value *SrcVal, const Type *DstTy,
ExecutionContext &SF);
GenericValue executeFPTruncInst(Value *SrcVal, const Type *DstTy,
ExecutionContext &SF);
GenericValue executeFPExtInst(Value *SrcVal, const Type *DstTy,
ExecutionContext &SF);
GenericValue executeFPToUIInst(Value *SrcVal, const Type *DstTy,
ExecutionContext &SF);
GenericValue executeFPToSIInst(Value *SrcVal, const Type *DstTy,
ExecutionContext &SF);
GenericValue executeUIToFPInst(Value *SrcVal, const Type *DstTy,
ExecutionContext &SF);
GenericValue executeSIToFPInst(Value *SrcVal, const Type *DstTy,
ExecutionContext &SF);
GenericValue executePtrToIntInst(Value *SrcVal, const Type *DstTy,
ExecutionContext &SF);
GenericValue executeIntToPtrInst(Value *SrcVal, const Type *DstTy,
ExecutionContext &SF);
GenericValue executeBitCastInst(Value *SrcVal, const Type *DstTy,
ExecutionContext &SF);
GenericValue executeCastOperation(Instruction::CastOps opcode, Value *SrcVal,
const Type *Ty, ExecutionContext &SF);
void popStackAndReturnValueToCaller(const Type *RetTy, GenericValue Result);
} // End llvm namespace