org.sonar.java.symexecengine.ExecutionState.java Source code

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Here is the source code for org.sonar.java.symexecengine.ExecutionState.java

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/*
 * SonarQube Java
 * Copyright (C) 2012 SonarSource
 * sonarqube@googlegroups.com
 *
 * 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 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
 */
package org.sonar.java.symexecengine;

import com.google.common.collect.HashMultimap;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.SetMultimap;
import com.google.common.collect.Sets;
import org.sonar.plugins.java.api.semantic.Symbol;
import org.sonar.plugins.java.api.tree.Tree;

import javax.annotation.CheckForNull;

import java.util.List;
import java.util.Map;
import java.util.Set;

public class ExecutionState {

    final ExecutionState parent;
    private SetMultimap<Symbol, SymbolicValue> reachableValues = HashMultimap.create();
    private SetMultimap<Symbol, SymbolicValue> unreachableValues = HashMultimap.create();
    /**
     * List of symbol that were declared within this execution state.
     */
    private List<Symbol> definedInState = Lists.newArrayList();
    private Map<SymbolicValue, State> stateOfValue = Maps.newHashMap();

    public ExecutionState(ExecutionState executionState) {
        this.parent = executionState;
        this.reachableValues = HashMultimap.create(executionState.reachableValues);
        this.unreachableValues = HashMultimap.create(executionState.unreachableValues);
    }

    /**
     * ParentState constructor.
     */
    public ExecutionState() {
        this.parent = null;
    }

    public void defineSymbol(Symbol symbol) {
        definedInState.add(symbol);
    }

    public ExecutionState merge(ExecutionState executionState) {
        for (Symbol symbol : executionState.reachableValues.keys()) {
            if (!executionState.definedInState.contains(symbol)) {
                this.reachableValues.putAll(symbol, executionState.reachableValues.get(symbol));
            }
        }
        for (Symbol symbol : executionState.unreachableValues.keys()) {
            if (!executionState.definedInState.contains(symbol)) {
                this.unreachableValues.putAll(symbol, executionState.unreachableValues.get(symbol));
            }
        }

        for (Symbol symbol : unreachableValues.keys()) {
            // cleanup after merge of reachable/unreachable values
            for (SymbolicValue value : unreachableValues.get(symbol)) {
                reachableValues.remove(symbol, value);
            }
        }
        // Merge states of values
        for (Map.Entry<SymbolicValue, State> valueStateEntry : executionState.stateOfValue.entrySet()) {
            SymbolicValue value = valueStateEntry.getKey();
            State state = valueStateEntry.getValue();
            State valueState = getStateOfValue(value);
            if (valueState == null) {
                valueState = state;
            } else {
                valueState = valueState.merge(state);
            }
            this.stateOfValue.put(value, valueState);
        }
        return this;
    }

    public ExecutionState overrideBy(ExecutionState executionState) {
        this.unreachableValues.putAll(executionState.unreachableValues);
        this.reachableValues = executionState.reachableValues;
        this.stateOfValue.putAll(executionState.stateOfValue);
        return this;
    }

    public ExecutionState restoreParent() {
        return parent.merge(this);
    }

    Set<State> getStatesOfCurrentExecutionState() {
        Set<State> results = Sets.newHashSet();
        for (Symbol symbol : definedInState) {
            for (SymbolicValue value : Iterables.concat(reachableValues.get(symbol),
                    unreachableValues.get(symbol))) {
                State state = stateOfValue.get(value);
                if (state != null) {
                    results.add(state);
                }
            }
        }
        return results;
    }

    // FIXME : Hideous hack for closeable to get "Ignored" variables
    public List<State> getStatesOf(Symbol symbol) {
        List<State> states = Lists.newArrayList();
        for (SymbolicValue value : Iterables.concat(reachableValues.get(symbol), unreachableValues.get(symbol))) {
            State state = stateOfValue.get(value);
            if (state != null) {
                states.add(state);
            }
        }
        return states;
    }

    @CheckForNull
    private State getStateOfValue(SymbolicValue value) {
        ExecutionState currentState = this;
        while (currentState != null) {
            State state = currentState.stateOfValue.get(value);
            if (state != null) {
                return state;
            }
            currentState = currentState.parent;
        }
        return null;
    }

    Iterable<SymbolicValue> getValues(Symbol symbol) {
        return reachableValues.get(symbol);
    }

    public SymbolicValue createValueForSymbol(Symbol symbol, Tree tree) {
        // When creating a new value, all reachable values are now unreachable.
        Set<SymbolicValue> values = this.reachableValues.get(symbol);
        unreachableValues.putAll(symbol, values);
        values.clear();
        SymbolicValue value = new SymbolicValue(tree);
        reachableValues.put(symbol, value);
        stateOfValue.put(value, State.UNSET);
        return value;
    }

    public void markValueAs(Symbol symbol, State state) {
        for (SymbolicValue value : getValues(symbol)) {
            stateOfValue.put(value, state);
        }
    }

    public void markValueAs(SymbolicValue value, State state) {
        stateOfValue.put(value, state);
    }

}