dataflow.src.org.checkerframework.dataflow.cfg.node.AssignmentNode Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of checker Show documentation

The Checker Framework enhances Java’s type system to make it more powerful and useful. This lets software developers detect and prevent errors in their Java programs. The Checker Framework includes compiler plug-ins ("checkers") that find bugs or verify their absence. It also permits you to write your own compiler plug-ins.

There is a newer version: 3.42.0

Show newest version

package org.checkerframework.dataflow.cfg.node;

import java.util.Collection;
import java.util.LinkedList;

import org.checkerframework.dataflow.cfg.node.AssignmentContext.AssignmentLhsContext;
import org.checkerframework.dataflow.util.HashCodeUtils;

import org.checkerframework.javacutil.InternalUtils;

import com.sun.source.tree.AssignmentTree;
import com.sun.source.tree.CompoundAssignmentTree;
import com.sun.source.tree.Tree;
import com.sun.source.tree.UnaryTree;
import com.sun.source.tree.VariableTree;

/**
 * A node for an assignment:
 *
 *  *   variable = expression
 *   expression . field = expression
 *   expression [ index ] = expression
 * 
 *
 * We allow assignments without corresponding AST {@link Tree}s.
 *
 * @author Stefan Heule
 *
 */
public class AssignmentNode extends Node {

    protected Tree tree;
    protected Node lhs;
    protected Node rhs;

    public AssignmentNode(Tree tree, Node target, Node expression) {
        super(InternalUtils.typeOf(tree));
        assert tree instanceof AssignmentTree || tree instanceof VariableTree
                || tree instanceof CompoundAssignmentTree || tree instanceof UnaryTree;
        assert target instanceof FieldAccessNode
                || target instanceof LocalVariableNode
                || target instanceof ArrayAccessNode;
        this.tree = tree;
        this.lhs = target;
        this.rhs = expression;
        rhs.setAssignmentContext(new AssignmentLhsContext(lhs));
    }

    public Node getTarget() {
        return lhs;
    }

    public Node getExpression() {
        return rhs;
    }

    @Override
    public Tree getTree() {
        return tree;
    }

    @Override
    public  R accept(NodeVisitor visitor, P p) {
        return visitor.visitAssignment(this, p);
    }

    @Override
    public String toString() {
        return getTarget() + " = " + getExpression();
    }

    @Override
    public boolean equals(Object obj) {
        if (obj == null || !(obj instanceof AssignmentNode)) {
            return false;
        }
        AssignmentNode other = (AssignmentNode) obj;
        return getTarget().equals(other.getTarget())
                && getExpression().equals(other.getExpression());
    }

    @Override
    public int hashCode() {
        return HashCodeUtils.hash(getTarget(), getExpression());
    }

    @Override
    public Collection getOperands() {
        LinkedList list = new LinkedList();
        list.add(getTarget());
        list.add(getExpression());
        return list;
    }
}