/******************************************************************************
* Copyright (c) 2002 - 2006 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*****************************************************************************/
package com.ibm.wala.cast.ir.ssa;
import com.ibm.wala.ssa.SSAInstruction;
import com.ibm.wala.ssa.SSAInstructionFactory;
import com.ibm.wala.ssa.SSAUnaryOpInstruction;
import com.ibm.wala.ssa.SymbolTable;
/**
* A simple assignment statement. Only appears in the IR before SSA conversion, and temporarily when needed to undo copy propagation
* during processing of new lexical definitions and uses.
*
* @author Julian Dolby (dolby@us.ibm.com)
*
*/
public class AssignInstruction extends SSAUnaryOpInstruction {
/**
* create the assignment v_result := v_val
*
* @param result
* @param val
*/
public AssignInstruction(int iindex, int result, int val) {
super(iindex, null, result, val);
assert result != val;
assert result != -1;
assert val != -1;
}
/*
* @see com.ibm.wala.ssa.SSAInstruction#copyForSSA(int[], int[])
*/
@Override
public SSAInstruction copyForSSA(SSAInstructionFactory insts, int[] defs, int[] uses) {
return ((AstInstructionFactory) insts)
.AssignInstruction(iindex, defs == null ? getDef(0) : defs[0], uses == null ? getUse(0) : uses[0]);
}
/*
* @see com.ibm.wala.ssa.SSAInstruction#toString(com.ibm.wala.ssa.SymbolTable, com.ibm.wala.ssa.ValueDecorator)
*/
@Override
public String toString(SymbolTable symbolTable) {
return getValueString(symbolTable, result) + " := " + getValueString(symbolTable, val);
}
/*
* @see com.ibm.wala.ssa.SSAInstruction#visit(com.ibm.wala.ssa.SSAInstruction.Visitor)
*/
@Override
public void visit(IVisitor v) {
((AstPreInstructionVisitor) v).visitAssign(this);
}
/**
* @return
*/
public int getVal() {
return getUse(0);
}
}