org.eclipse.jdt.internal.compiler.ast.NullLiteral.java Source code

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Here is the source code for org.eclipse.jdt.internal.compiler.ast.NullLiteral.java

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/*******************************************************************************
 * Copyright (c) 2000, 2013 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Stephan Herrmann - Contribution for
 *                        bug 383368 - [compiler][null] syntactic null analysis for field references
 *******************************************************************************/
package org.eclipse.jdt.internal.compiler.ast;

import org.eclipse.jdt.internal.compiler.ASTVisitor;
import org.eclipse.jdt.internal.compiler.codegen.*;
import org.eclipse.jdt.internal.compiler.flow.FlowContext;
import org.eclipse.jdt.internal.compiler.flow.FlowInfo;
import org.eclipse.jdt.internal.compiler.impl.Constant;
import org.eclipse.jdt.internal.compiler.lookup.*;

public class NullLiteral extends MagicLiteral {

    static final char[] source = { 'n', 'u', 'l', 'l' };

    public NullLiteral(int s, int e) {

        super(s, e);
    }

    @Override
    public void computeConstant() {

        this.constant = Constant.NotAConstant;
    }

    /**
     * Code generation for the null literal
     *
     * @param currentScope org.eclipse.jdt.internal.compiler.lookup.BlockScope
     * @param codeStream org.eclipse.jdt.internal.compiler.codegen.CodeStream
     * @param valueRequired boolean
     */
    @Override
    public void generateCode(BlockScope currentScope, CodeStream codeStream, boolean valueRequired) {
        int pc = codeStream.position;
        if (valueRequired) {
            codeStream.aconst_null();
            codeStream.generateImplicitConversion(this.implicitConversion);
        }
        codeStream.recordPositionsFrom(pc, this.sourceStart);
    }

    @Override
    public TypeBinding literalType(BlockScope scope) {
        return TypeBinding.NULL;
    }

    @Override
    public int nullStatus(FlowInfo flowInfo, FlowContext flowContext) {
        return FlowInfo.NULL;
    }

    @Override
    public Object reusableJSRTarget() {
        return TypeBinding.NULL;
    }

    @Override
    public char[] source() {
        return source;
    }

    @Override
    public void traverse(ASTVisitor visitor, BlockScope scope) {
        visitor.visit(this, scope);
        visitor.endVisit(this, scope);
    }
}