69 lines
2.4 KiB
Java
69 lines
2.4 KiB
Java
/*******************************************************************************
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* Copyright (c) 2007 IBM Corporation.
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* All rights reserved. This program and the accompanying materials
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* are made available under the terms of the Eclipse Public License v1.0
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* which accompanies this distribution, and is available at
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* http://www.eclipse.org/legal/epl-v10.html
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*
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* Contributors:
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* IBM Corporation - initial API and implementation
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*******************************************************************************/
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package com.ibm.wala.cfg.exc.intra;
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import com.ibm.wala.cfg.exc.intra.NullPointerState.State;
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import com.ibm.wala.dataflow.graph.DataflowSolver;
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import com.ibm.wala.ssa.IR;
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import com.ibm.wala.ssa.ISSABasicBlock;
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/**
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* Intraprocedural dataflow analysis to detect impossible NullPointerExceptions.
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*
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* @author Juergen Graf <graf@kit.edu>
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*
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*/
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public class NullPointerSolver<B extends ISSABasicBlock> extends DataflowSolver<B, NullPointerState> {
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private final int maxVarNum;
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private final ParameterState parameterState;
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private final B entry;
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private final IR ir;
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public NullPointerSolver(NullPointerFrameWork<B> problem, int maxVarNum, IR ir, B entry) {
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this(problem, maxVarNum, entry, ir, ParameterState.createDefault(ir.getMethod()));
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}
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public NullPointerSolver(NullPointerFrameWork<B> problem, int maxVarNum, B entry, IR ir, ParameterState initialState) {
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super(problem);
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this.maxVarNum = maxVarNum;
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this.parameterState = initialState;
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this.entry = entry;
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this.ir = ir;
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}
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/* (non-Javadoc)
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* @see com.ibm.wala.dataflow.graph.DataflowSolver#makeEdgeVariable(java.lang.Object, java.lang.Object)
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*/
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@Override
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protected NullPointerState makeEdgeVariable(B src, B dst) {
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return new NullPointerState(maxVarNum, ir.getSymbolTable(), parameterState);
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}
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/* (non-Javadoc)
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* @see com.ibm.wala.dataflow.graph.DataflowSolver#makeNodeVariable(java.lang.Object, boolean)
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*/
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@Override
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protected NullPointerState makeNodeVariable(B n, boolean IN) {
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if (IN && n.equals(entry)) {
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return new NullPointerState(maxVarNum, ir.getSymbolTable(), parameterState, State.BOTH);
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} else {
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return new NullPointerState(maxVarNum, ir.getSymbolTable(), parameterState, State.UNKNOWN);
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}
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}
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@Override
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protected NullPointerState[] makeStmtRHS(int size) {
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return new NullPointerState[size];
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}
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}
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