qilin.pta.toolkits.turner.DFA Maven / Gradle / Ivy

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/* Qilin - a Java Pointer Analysis Framework
 * Copyright (C) 2021-2030 Qilin developers
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3.0 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Lesser Public License for more details.
 *
 * You should have received a copy of the GNU General Lesser Public
 * License along with this program.  If not, see
 * .
 */

package qilin.pta.toolkits.turner;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

public class DFA {
  public enum State {
    S,
    FLOW,
    IFLOW,
    E,
    ERROR;
  }

  public enum TranCond {
    PARAM,
    IPARAM,
    ASSIGN,
    IASSIGN,
    LOAD,
    ILOAD,
    STORE,
    ISTORE,
    NEW,
    INEW,
    CSLIKELY;
  }

  private static final Map> transitionFunc = new HashMap<>();

  static {
    Map mS = transitionFunc.computeIfAbsent(State.S, k -> new HashMap<>());
    mS.put(TranCond.PARAM, State.FLOW);

    Map mFlow = transitionFunc.computeIfAbsent(State.FLOW, k -> new HashMap<>());
    mFlow.put(TranCond.ASSIGN, State.FLOW);
    mFlow.put(TranCond.LOAD, State.FLOW);
    mFlow.put(TranCond.STORE, State.IFLOW);
    mFlow.put(TranCond.ISTORE, State.IFLOW);
    mFlow.put(TranCond.NEW, State.FLOW);

    Map mIFlow = transitionFunc.computeIfAbsent(State.IFLOW, k -> new HashMap<>());
    mIFlow.put(TranCond.IASSIGN, State.IFLOW);
    mIFlow.put(TranCond.ILOAD, State.IFLOW);
    mIFlow.put(TranCond.IPARAM, State.E);
    mIFlow.put(TranCond.INEW, State.IFLOW);
    mIFlow.put(TranCond.CSLIKELY, State.FLOW);
  }

  public static State nextState(State curr, TranCond tranCond) {
    return transitionFunc
        .getOrDefault(curr, Collections.emptyMap())
        .getOrDefault(tranCond, State.ERROR);
  }
}