jjg@309: /*
jjg@309:  * Copyright 2009 Sun Microsystems, Inc.  All Rights Reserved.
jjg@309:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
jjg@309:  *
jjg@309:  * This code is free software; you can redistribute it and/or modify it
jjg@309:  * under the terms of the GNU General Public License version 2 only, as
jjg@309:  * published by the Free Software Foundation.  Sun designates this
jjg@309:  * particular file as subject to the "Classpath" exception as provided
jjg@309:  * by Sun in the LICENSE file that accompanied this code.
jjg@309:  *
jjg@309:  * This code is distributed in the hope that it will be useful, but WITHOUT
jjg@309:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
jjg@309:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
jjg@309:  * version 2 for more details (a copy is included in the LICENSE file that
jjg@309:  * accompanied this code).
jjg@309:  *
jjg@309:  * You should have received a copy of the GNU General Public License version
jjg@309:  * 2 along with this work; if not, write to the Free Software Foundation,
jjg@309:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
jjg@309:  *
jjg@309:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
jjg@309:  * CA 95054 USA or visit www.sun.com if you need additional information or
jjg@309:  * have any questions.
jjg@309:  */
jjg@309: 
jjg@309: package com.sun.source.util;
jjg@309: 
jjg@309: import java.util.ArrayList;
jjg@309: import java.util.HashSet;
jjg@309: import java.util.List;
jjg@309: import java.util.Set;
jjg@309: 
jjg@309: import javax.annotation.processing.*;
jjg@309: import javax.lang.model.element.Name;
jjg@309: import javax.lang.model.element.TypeElement;
jjg@309: import javax.lang.model.util.ElementFilter;
jjg@309: 
jjg@309: import com.sun.tools.javac.processing.JavacProcessingEnvironment;
jjg@309: import com.sun.tools.javac.util.Context;
jjg@309: import com.sun.tools.javac.util.Log;
jjg@309: 
jjg@309: import com.sun.source.tree.ClassTree;
jjg@309: 
jjg@309: /**
jjg@309:  * This class is an abstract annotation processor designed to be a
jjg@309:  * convenient superclass for concrete "type processors", processors that
jjg@309:  * require the type information in the processed source.
jjg@309:  *
jjg@309:  * <p>Type processing occurs in one round after the tool (e.g. java compiler)
jjg@309:  * analyzes the source (all sources taken as input to the tool and sources
jjg@309:  * generated by other annotation processors).
jjg@309:  *
jjg@309:  * <p>The tool infrastructure will interact with classes extending this abstract
jjg@309:  * class as follows:
jjg@309:  *
jjg@309:  * <ol>
jjg@309:  * [1-3: Identical to {@link Processor} life cycle]
jjg@309:  *
jjg@309:  * <li>If an existing {@code Processor} object is not being used, to
jjg@309:  * create an instance of a processor the tool calls the no-arg
jjg@309:  * constructor of the processor class.
jjg@309:  *
jjg@309:  * <li>Next, the tool calls the {@link #init init} method with
jjg@309:  * an appropriate {@code ProcessingEnvironment}.
jjg@309:  *
jjg@309:  * <li>Afterwards, the tool calls {@link #getSupportedAnnotationTypes
jjg@309:  * getSupportedAnnotationTypes}, {@link #getSupportedOptions
jjg@309:  * getSupportedOptions}, and {@link #getSupportedSourceVersion
jjg@309:  * getSupportedSourceVersion}.  These methods are only called once per
jjg@309:  * run, not on each round.
jjg@309:  *
jjg@309:  * [4-5Unique to {@code AbstractTypeProcessor} subclasses]
jjg@309:  *
jjg@309:  * <li>For each class containing a supported annotation, the tool calls
jjg@309:  * {@link #typeProcess(TypeElement, TreePath) typeProcess} method on the
jjg@309:  * {@code Processor}.  The class is guaranteed to be type-checked Java code
jjg@309:  * and all the tree type and symbol information is resolved.
jjg@309:  *
jjg@309:  * <li>Finally, the tools calls the
jjg@309:  * {@link #typeProcessingOver() typeProcessingOver} method
jjg@309:  * on the {@code Processor}.
jjg@309:  *
jjg@309:  * </ol>
jjg@309:  *
jjg@309:  * <p>The tool is permitted to ask type processors to process a class once
jjg@309:  * it is analyzed before the rest of classes are analyzed.  The tool is also
jjg@309:  * permitted to stop type processing immediately if any errors are raised,
jjg@309:  * without invoking {@code typeProcessingOver}
jjg@309:  *
jjg@309:  * <p>A subclass may override any of the methods in this class, as long as the
jjg@309:  * general {@link javax.annotation.processing.Processor Processor}
jjg@309:  * contract is obeyed, with one notable exception.
jjg@309:  * {@link #process(Set, RoundEnvironment)} may not be overridden, as it
jjg@309:  * is called during the regular annotation phase before classes are analyzed.
jjg@309:  *
jjg@309:  * @author Mahmood Ali
jjg@309:  * @since 1.7
jjg@309:  */
jjg@309: public abstract class AbstractTypeProcessor extends AbstractProcessor {
jjg@309:     private final Set<Name> elements = new HashSet<Name>();
jjg@309:     private boolean hasInvokedTypeProcessingOver = false;
jjg@309:     private JavacProcessingEnvironment env;
jjg@309:     private final AttributionTaskListener listener = new AttributionTaskListener();
jjg@309: 
jjg@309:     /**
jjg@309:      * Constructor for subclasses to call.
jjg@309:      */
jjg@309:     protected AbstractTypeProcessor() { }
jjg@309: 
jjg@309:     /**
jjg@309:      * {@inheritDoc}
jjg@309:      */
jjg@309:     @Override
jjg@309:     public void init(ProcessingEnvironment env) {
jjg@309:         super.init(env);
jjg@309:         this.env = (JavacProcessingEnvironment)env;
jjg@309:         prepareContext(this.env.getContext());
jjg@309:     }
jjg@309: 
jjg@309:     /**
jjg@309:      * The use of this method is obsolete in type processors.  The method is
jjg@309:      * called during regular annotation processing phase only.
jjg@309:      */
jjg@309:     @Override
jjg@309:     public final boolean process(Set<? extends TypeElement> annotations,
jjg@309:             RoundEnvironment roundEnv) {
jjg@309:         for (TypeElement elem : ElementFilter.typesIn(roundEnv.getRootElements())) {
jjg@309:             elements.add(elem.getQualifiedName());
jjg@309:         }
jjg@309:         return false;
jjg@309:     }
jjg@309: 
jjg@309:     /**
jjg@309:      * Processes a fully analyzed class that contains a supported annotation
jjg@309:      * (look {@link #getSupportedAnnotationTypes()}).
jjg@309:      *
jjg@309:      * <p>The passed class is always a valid type-checked Java code.
jjg@309:      *
jjg@309:      * @param element       element of the analyzed class
jjg@309:      * @param tree  the tree path to the element, with the leaf being a
jjg@309:      *              {@link ClassTree}
jjg@309:      */
jjg@309:     public abstract void typeProcess(TypeElement element, TreePath tree);
jjg@309: 
jjg@309:     /**
jjg@309:      * A method to be called once all the classes are processed and no error
jjg@309:      * is reported.
jjg@309:      *
jjg@309:      * <p>Subclasses may override this method to do any aggregate analysis
jjg@309:      * (e.g. generate report, persistence) or resource deallocation.
jjg@309:      *
jjg@309:      * <p>If an error (a Java error or a processor error) is reported, this
jjg@309:      * method is not guaranteed to be invoked.
jjg@309:      */
jjg@309:     public void typeProcessingOver() { }
jjg@309: 
jjg@309:     /**
jjg@309:      * adds a listener for attribution.
jjg@309:      */
jjg@309:     private void prepareContext(Context context) {
jjg@309:         TaskListener otherListener = context.get(TaskListener.class);
jjg@309:         if (otherListener == null) {
jjg@309:             context.put(TaskListener.class, listener);
jjg@309:         } else {
jjg@309:             // handle cases of multiple listeners
jjg@309:             context.put(TaskListener.class, (TaskListener)null);
jjg@309:             TaskListeners listeners = new TaskListeners();
jjg@309:             listeners.add(otherListener);
jjg@309:             listeners.add(listener);
jjg@309:             context.put(TaskListener.class, listeners);
jjg@309:         }
jjg@309:     }
jjg@309: 
jjg@309:     /**
jjg@309:      * A task listener that invokes the processor whenever a class is fully
jjg@309:      * analyzed.
jjg@309:      */
jjg@309:     private final class AttributionTaskListener implements TaskListener {
jjg@309: 
jjg@309:         @Override
jjg@309:         public void finished(TaskEvent e) {
jjg@309:             Log log = Log.instance(env.getContext());
jjg@309: 
jjg@309:             if (!hasInvokedTypeProcessingOver && elements.isEmpty() && log.nerrors == 0) {
jjg@309:                 typeProcessingOver();
jjg@309:                 hasInvokedTypeProcessingOver = true;
jjg@309:             }
jjg@309: 
jjg@309:             if (e.getKind() != TaskEvent.Kind.ANALYZE)
jjg@309:                 return;
jjg@309: 
jjg@309:             if (e.getTypeElement() == null)
jjg@309:                 throw new AssertionError("event task without a type element");
jjg@309:             if (e.getCompilationUnit() == null)
jjg@309:                 throw new AssertionError("even task without compilation unit");
jjg@309: 
jjg@309:             if (!elements.remove(e.getTypeElement().getQualifiedName()))
jjg@309:                 return;
jjg@309: 
jjg@309:             if (log.nerrors != 0)
jjg@309:                 return;
jjg@309: 
jjg@309:             TypeElement elem = e.getTypeElement();
jjg@309:             TreePath p = Trees.instance(env).getPath(elem);
jjg@309: 
jjg@309:             typeProcess(elem, p);
jjg@309: 
jjg@309:             if (!hasInvokedTypeProcessingOver && elements.isEmpty() && log.nerrors == 0) {
jjg@309:                 typeProcessingOver();
jjg@309:                 hasInvokedTypeProcessingOver = true;
jjg@309:             }
jjg@309:         }
jjg@309: 
jjg@309:         @Override
jjg@309:         public void started(TaskEvent e) { }
jjg@309: 
jjg@309:     }
jjg@309: 
jjg@309:     /**
jjg@309:      * A task listener multiplexer.
jjg@309:      */
jjg@309:     private static class TaskListeners implements TaskListener {
jjg@309:         private final List<TaskListener> listeners = new ArrayList<TaskListener>();
jjg@309: 
jjg@309:         public void add(TaskListener listener) {
jjg@309:             listeners.add(listener);
jjg@309:         }
jjg@309: 
jjg@309:         public void remove(TaskListener listener) {
jjg@309:             listeners.remove(listener);
jjg@309:         }
jjg@309: 
jjg@309:         @Override
jjg@309:         public void finished(TaskEvent e) {
jjg@309:             for (TaskListener listener : listeners)
jjg@309:                 listener.finished(e);
jjg@309:         }
jjg@309: 
jjg@309:         @Override
jjg@309:         public void started(TaskEvent e) {
jjg@309:             for (TaskListener listener : listeners)
jjg@309:                 listener.started(e);
jjg@309:         }
jjg@309:     }
jjg@309: }