1/* 2 * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23package org.graalvm.compiler.serviceprovider.processor; 24 25import java.io.IOException; 26import java.io.OutputStreamWriter; 27import java.io.PrintWriter; 28import java.util.HashMap; 29import java.util.HashSet; 30import java.util.Map; 31import java.util.Map.Entry; 32import java.util.Set; 33 34import javax.annotation.processing.AbstractProcessor; 35import javax.annotation.processing.FilerException; 36import javax.annotation.processing.RoundEnvironment; 37import javax.annotation.processing.SupportedAnnotationTypes; 38import javax.lang.model.SourceVersion; 39import javax.lang.model.element.Element; 40import javax.lang.model.element.TypeElement; 41import javax.lang.model.type.MirroredTypeException; 42import javax.lang.model.type.TypeMirror; 43import javax.tools.Diagnostic.Kind; 44import javax.tools.FileObject; 45import javax.tools.StandardLocation; 46 47import org.graalvm.compiler.serviceprovider.ServiceProvider; 48 49/** 50 * Processes classes annotated with {@link ServiceProvider}. For a service defined by {@code S} and 51 * a class {@code P} implementing the service, this processor generates the file 52 * {@code META-INF/providers/P} whose contents are a single line containing the fully qualified name 53 * of {@code S}. 54 */ 55@SupportedAnnotationTypes("org.graalvm.compiler.serviceprovider.ServiceProvider") 56public class ServiceProviderProcessor extends AbstractProcessor { 57 58 private final Set<TypeElement> processed = new HashSet<>(); 59 private final Map<TypeElement, String> serviceProviders = new HashMap<>(); 60 61 @Override 62 public SourceVersion getSupportedSourceVersion() { 63 return SourceVersion.latest(); 64 } 65 66 private boolean verifyAnnotation(TypeMirror serviceInterface, TypeElement serviceProvider) { 67 if (!processingEnv.getTypeUtils().isSubtype(serviceProvider.asType(), serviceInterface)) { 68 String msg = String.format("Service provider class %s must implement service interface %s", serviceProvider.getSimpleName(), serviceInterface); 69 processingEnv.getMessager().printMessage(Kind.ERROR, msg, serviceProvider); 70 return false; 71 } 72 73 return true; 74 } 75 76 private void processElement(TypeElement serviceProvider) { 77 if (processed.contains(serviceProvider)) { 78 return; 79 } 80 81 processed.add(serviceProvider); 82 ServiceProvider annotation = serviceProvider.getAnnotation(ServiceProvider.class); 83 if (annotation != null) { 84 try { 85 annotation.value(); 86 } catch (MirroredTypeException ex) { 87 TypeMirror serviceInterface = ex.getTypeMirror(); 88 if (verifyAnnotation(serviceInterface, serviceProvider)) { 89 if (serviceProvider.getNestingKind().isNested()) { 90 /* 91 * This is a simplifying constraint that means we don't have to process the 92 * qualified name to insert '$' characters at the relevant positions. 93 */ 94 String msg = String.format("Service provider class %s must be a top level class", serviceProvider.getSimpleName()); 95 processingEnv.getMessager().printMessage(Kind.ERROR, msg, serviceProvider); 96 } else { 97 serviceProviders.put(serviceProvider, ex.getTypeMirror().toString()); 98 } 99 } 100 } 101 } 102 } 103 104 private void writeProviderFile(TypeElement serviceProvider, String interfaceName) { 105 String filename = "META-INF/providers/" + serviceProvider.getQualifiedName(); 106 try { 107 FileObject file = processingEnv.getFiler().createResource(StandardLocation.CLASS_OUTPUT, "", filename, serviceProvider); 108 PrintWriter writer = new PrintWriter(new OutputStreamWriter(file.openOutputStream(), "UTF-8")); 109 writer.println(interfaceName); 110 writer.close(); 111 } catch (IOException e) { 112 processingEnv.getMessager().printMessage(isBug367599(e) ? Kind.NOTE : Kind.ERROR, e.getMessage(), serviceProvider); 113 } 114 } 115 116 /** 117 * Determines if a given exception is (most likely) caused by 118 * <a href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=367599">Bug 367599</a>. 119 */ 120 private static boolean isBug367599(Throwable t) { 121 if (t instanceof FilerException) { 122 for (StackTraceElement ste : t.getStackTrace()) { 123 if (ste.toString().contains("org.eclipse.jdt.internal.apt.pluggable.core.filer.IdeFilerImpl.create")) { 124 // See: https://bugs.eclipse.org/bugs/show_bug.cgi?id=367599 125 return true; 126 } 127 } 128 } 129 return t.getCause() != null && isBug367599(t.getCause()); 130 } 131 132 @Override 133 public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) { 134 if (roundEnv.processingOver()) { 135 for (Entry<TypeElement, String> e : serviceProviders.entrySet()) { 136 writeProviderFile(e.getKey(), e.getValue()); 137 } 138 serviceProviders.clear(); 139 return true; 140 } 141 142 for (Element element : roundEnv.getElementsAnnotatedWith(ServiceProvider.class)) { 143 assert element.getKind().isClass(); 144 processElement((TypeElement) element); 145 } 146 147 return true; 148 } 149} 150