javacroundenvironment.java

是一款用JAVA 编写的编译器 具有很强的编译功能

/*
 * Copyright 2005-2006 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code 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 Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package com.sun.tools.javac.processing;

import java.lang.annotation.Annotation;
import com.sun.tools.javac.util.*;
import com.sun.tools.javac.comp.*;
import com.sun.tools.javac.tree.JCTree.*;
import javax.annotation.processing.*;
import javax.lang.model.element.*;
import javax.lang.model.type.DeclaredType;
import javax.lang.model.type.TypeMirror;
import javax.lang.model.util.*;
import java.util.*;

/** 
 * Object providing state about a prior round of annotation processing.
 *
 * <p><b>This is NOT part of any API supported by Sun Microsystems.
 * If you write code that depends on this, you do so at your own risk.
 * This code and its internal interfaces are subject to change or
 * deletion without notice.</b>
 */
public class JavacRoundEnvironment implements RoundEnvironment {
    // Default equals and hashCode methods are okay.

    private final boolean processingOver;
    private final boolean errorRaised;
    private final ProcessingEnvironment processingEnv;

    // Caller must pass in an immutable set
    private final Set<? extends Element> rootElements;

    JavacRoundEnvironment(boolean processingOver,
			  boolean errorRaised,
			  Set<? extends Element> rootElements,
			  ProcessingEnvironment processingEnv) {
	this.processingOver = processingOver;
	this.errorRaised = errorRaised;
	this.rootElements = rootElements;
        this.processingEnv = processingEnv;
    }

    public String toString() {
	return String.format("[errorRaised=%b, rootElements=%s, processingOver=%b]",
			     errorRaised,
			     rootElements,
			     processingOver);
    }

    public boolean processingOver() {
	return processingOver;
    }
 
    /**
     * Returns {@code true} if an error was raised in the prior round
     * of processing; returns {@code false} otherwise.
     * 
     * @return {@code true} if an error was raised in the prior round
     * of processing; returns {@code false} otherwise.
     */
    public boolean errorRaised() {
	return errorRaised;
    }

    /**
     * Returns the type elements specified by the prior round.
     *
     * @return the types elements specified by the prior round, or an
     * empty set if there were none
     */
    public Set<? extends Element> getRootElements() {
	return rootElements;
    }

    private static final String NOT_AN_ANNOTATION_TYPE = 
	"The argument does not represent an annotation type: ";

    /**
     * Returns the elements annotated with the given annotation type.
     * Only type elements <i>included</i> in this round of annotation
     * processing, or declarations of members, parameters, or type
     * parameters declared within those, are returned.  Included type
     * elements are {@linkplain #getSpecifiedTypeElements specified
     * types} and any types nested within them.
     *
     * @param a  annotation type being requested
     * @return the elements annotated with the given annotation type,
     * or an empty set if there are none
     */
    public Set<? extends Element> getElementsAnnotatedWith(TypeElement a) {
	Set<Element> result = Collections.emptySet();
	if (a.getKind() != ElementKind.ANNOTATION_TYPE)
	    throw new IllegalArgumentException(NOT_AN_ANNOTATION_TYPE + a);
	
	DeclaredType annotationTypeElement; 
	TypeMirror tm = a.asType();
	if ( tm instanceof DeclaredType )
	    annotationTypeElement = (DeclaredType) a.asType();
	else
	    throw new AssertionError("Bad implementation type for " + tm);

	ElementScanner6<Set<Element>, DeclaredType> scanner = 
	    new AnnotationSetScanner(result);
	
	for (Element element : rootElements)
	    result = scanner.scan(element, annotationTypeElement);

	return result;
    }

    // Could be written as a local class inside getElementsAnnotatedWith
    private class AnnotationSetScanner extends
	ElementScanner6<Set<Element>, DeclaredType> {
	// Insertion-order preserving set
	Set<Element> annotatedElements = new LinkedHashSet<Element>();

	AnnotationSetScanner(Set<Element> defaultSet) {
	    super(defaultSet);
	}

	@Override
	public Set<Element> scan(Element e, DeclaredType p) {
	    java.util.List<? extends AnnotationMirror> annotationMirrors = 
		processingEnv.getElementUtils().getAllAnnotationMirrors(e);
	    for (AnnotationMirror annotationMirror : annotationMirrors) {
		if (annotationMirror.getAnnotationType().equals(p))
		    annotatedElements.add(e);
	    }
	    e.accept(this, p);
	    return annotatedElements;
	}

    }

    /**
     * {@inheritdoc}
     */
    public Set<? extends Element> getElementsAnnotatedWith(Class<? extends Annotation> a) {
	if (!a.isAnnotation())
	    throw new IllegalArgumentException(NOT_AN_ANNOTATION_TYPE + a);
	String name = a.getCanonicalName();
	if (name == null)
	    return Collections.emptySet();
	else {
	    TypeElement annotationType = processingEnv.getElementUtils().getTypeElement(name);
	    if (annotationType == null)
		return Collections.emptySet();
	    else
		return getElementsAnnotatedWith(annotationType);
	}
    } 
}