001/*
002 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package jdk.internal.jvmci.service.processor;
024
025import java.io.*;
026import java.util.*;
027
028import javax.annotation.processing.*;
029import javax.lang.model.*;
030import javax.lang.model.element.*;
031import javax.lang.model.type.*;
032import javax.tools.Diagnostic.Kind;
033import javax.tools.*;
034
035import jdk.internal.jvmci.service.*;
036
037@SupportedAnnotationTypes("jdk.internal.jvmci.service.ServiceProvider")
038public class ServiceProviderProcessor extends AbstractProcessor {
039
040    private final Set<TypeElement> processed = new HashSet<>();
041
042    @Override
043    public SourceVersion getSupportedSourceVersion() {
044        return SourceVersion.latest();
045    }
046
047    private boolean verifyAnnotation(TypeMirror serviceInterface, TypeElement serviceProvider) {
048        if (!processingEnv.getTypeUtils().isSubtype(serviceProvider.asType(), serviceInterface)) {
049            String msg = String.format("Service provider class %s must implement service interface %s", serviceProvider.getSimpleName(), serviceInterface);
050            processingEnv.getMessager().printMessage(Kind.ERROR, msg, serviceProvider);
051            return false;
052        }
053
054        return true;
055    }
056
057    private void processElement(TypeElement serviceProvider) {
058        if (processed.contains(serviceProvider)) {
059            return;
060        }
061
062        processed.add(serviceProvider);
063        ServiceProvider annotation = serviceProvider.getAnnotation(ServiceProvider.class);
064        if (annotation != null) {
065            try {
066                annotation.value();
067            } catch (MirroredTypeException ex) {
068                TypeMirror serviceInterface = ex.getTypeMirror();
069                if (verifyAnnotation(serviceInterface, serviceProvider)) {
070                    String interfaceName = ex.getTypeMirror().toString();
071                    createProviderFile(serviceProvider, interfaceName);
072                }
073            }
074        }
075    }
076
077    private void createProviderFile(TypeElement serviceProvider, String interfaceName) {
078        if (serviceProvider.getNestingKind().isNested()) {
079            // This is a simplifying constraint that means we don't have to
080            // processed the qualified name to insert '$' characters at
081            // the relevant positions.
082            String msg = String.format("Service provider class %s must be a top level class", serviceProvider.getSimpleName());
083            processingEnv.getMessager().printMessage(Kind.ERROR, msg, serviceProvider);
084            return;
085        }
086
087        String filename = "META-INF/jvmci.providers/" + serviceProvider.getQualifiedName();
088        try {
089            FileObject file = processingEnv.getFiler().createResource(StandardLocation.CLASS_OUTPUT, "", filename, serviceProvider);
090            PrintWriter writer = new PrintWriter(new OutputStreamWriter(file.openOutputStream(), "UTF-8"));
091            writer.println(interfaceName);
092            writer.close();
093        } catch (IOException e) {
094            processingEnv.getMessager().printMessage(Kind.ERROR, e.getMessage(), serviceProvider);
095        }
096    }
097
098    @Override
099    public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
100        if (roundEnv.processingOver()) {
101            return true;
102        }
103
104        for (Element element : roundEnv.getElementsAnnotatedWith(ServiceProvider.class)) {
105            assert element.getKind().isClass();
106            processElement((TypeElement) element);
107        }
108
109        return true;
110    }
111}