/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
package org.codehaus.groovy.control.customizers;

import org.codehaus.groovy.control.CompilationUnit;
import org.codehaus.groovy.control.CompilePhase;

/**
 * Users wanting to customize the configuration process such as adding imports, restricting the
 * language features or apply AST transformations by default should implement this class, then
 * call the {@link org.codehaus.groovy.control.CompilerConfiguration#addCompilationCustomizers(CompilationCustomizer...)}
 * method.
 * <p>
 * A customizer is registered for a particular compilation and is invoked for every primary class
 * node of it. Two consequences are easy to overlook:
 * <ul>
 * <li>The {@code SourceUnit} passed to
 * {@link CompilationUnit.IPrimaryClassNodeOperation#call(org.codehaus.groovy.control.SourceUnit,
 * org.codehaus.groovy.classgen.GeneratorContext, org.codehaus.groovy.ast.ClassNode) call} may be
 * {@code null}, for class nodes supplied directly via
 * {@link CompilationUnit#addClassNode(org.codehaus.groovy.ast.ClassNode) addClassNode} rather than
 * parsed from source. Guard accordingly; an unguarded dereference surfaces as a
 * {@link org.codehaus.groovy.GroovyBugError} rather than as your own exception.</li>
 * <li>A customizer should not assume the class nodes it sees belong to the compilation it was
 * registered for. A configuration may be copied for a nested compilation, which carries its
 * customizers along unless
 * {@linkplain org.codehaus.groovy.control.CompilerConfiguration#CompilerConfiguration(org.codehaus.groovy.control.CompilerConfiguration,
 * boolean) the two-argument copy constructor} is used to omit them.</li>
 * </ul>
 *
 * @since 1.8.0
 */
public abstract class CompilationCustomizer implements CompilationUnit.IPrimaryClassNodeOperation {
    private final CompilePhase phase;

    /**
     * Creates a customizer bound to the supplied compile phase.
     *
     * @param phase the phase in which this customizer should run
     */
    public CompilationCustomizer(final CompilePhase phase) {
        this.phase = phase;
    }

    /**
     * Returns the compile phase in which this customizer runs.
     *
     * @return the configured compile phase
     */
    public CompilePhase getPhase() {
        return phase;
    }
}
