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 */
23 package org.graalvm.compiler.serviceprovider.processor;
24
25 import java.io.IOException;
26 import java.io.OutputStreamWriter;
27 import java.io.PrintWriter;
28 import java.util.HashSet;
29 import java.util.Set;
30
31 import javax.annotation.processing.AbstractProcessor;
32 import javax.annotation.processing.FilerException;
33 import javax.annotation.processing.RoundEnvironment;
34 import javax.annotation.processing.SupportedAnnotationTypes;
35 import javax.lang.model.SourceVersion;
36 import javax.lang.model.element.Element;
37 import javax.lang.model.element.TypeElement;
38 import javax.lang.model.type.MirroredTypeException;
39 import javax.lang.model.type.TypeMirror;
40 import javax.tools.Diagnostic.Kind;
41 import javax.tools.FileObject;
42 import javax.tools.StandardLocation;
43
44 import org.graalvm.compiler.serviceprovider.ServiceProvider;
45
46 /**
47 * Processes classes annotated with {@link ServiceProvider}. For a service defined by {@code S} and
48 * a class {@code P} implementing the service, this processor generates the file
49 * {@code META-INF/providers/P} whose contents are a single line containing the fully qualified name
50 * of {@code S}.
51 */
52 @SupportedAnnotationTypes("org.graalvm.compiler.serviceprovider.ServiceProvider")
53 public class ServiceProviderProcessor extends AbstractProcessor {
54
55 private final Set<TypeElement> processed = new HashSet<>();
56
57 @Override
58 public SourceVersion getSupportedSourceVersion() {
59 return SourceVersion.latest();
60 }
61
62 private boolean verifyAnnotation(TypeMirror serviceInterface, TypeElement serviceProvider) {
63 if (!processingEnv.getTypeUtils().isSubtype(serviceProvider.asType(), serviceInterface)) {
64 String msg = String.format("Service provider class %s must implement service interface %s", serviceProvider.getSimpleName(), serviceInterface);
65 processingEnv.getMessager().printMessage(Kind.ERROR, msg, serviceProvider);
66 return false;
67 }
68
69 return true;
70 }
71
72 private void processElement(TypeElement serviceProvider) {
73 if (processed.contains(serviceProvider)) {
74 return;
75 }
76
77 processed.add(serviceProvider);
78 ServiceProvider annotation = serviceProvider.getAnnotation(ServiceProvider.class);
79 if (annotation != null) {
80 try {
81 annotation.value();
82 } catch (MirroredTypeException ex) {
83 TypeMirror serviceInterface = ex.getTypeMirror();
84 if (verifyAnnotation(serviceInterface, serviceProvider)) {
85 String interfaceName = ex.getTypeMirror().toString();
86 createProviderFile(serviceProvider, interfaceName);
87 }
88 }
89 }
90 }
91
92 private void createProviderFile(TypeElement serviceProvider, String interfaceName) {
93 if (serviceProvider.getNestingKind().isNested()) {
94 // This is a simplifying constraint that means we don't have to
95 // processed the qualified name to insert '$' characters at
96 // the relevant positions.
97 String msg = String.format("Service provider class %s must be a top level class", serviceProvider.getSimpleName());
98 processingEnv.getMessager().printMessage(Kind.ERROR, msg, serviceProvider);
99 return;
100 }
101
102 String filename = "META-INF/providers/" + serviceProvider.getQualifiedName();
103 try {
104 FileObject file = processingEnv.getFiler().createResource(StandardLocation.CLASS_OUTPUT, "", filename, serviceProvider);
105 PrintWriter writer = new PrintWriter(new OutputStreamWriter(file.openOutputStream(), "UTF-8"));
106 writer.println(interfaceName);
107 writer.close();
108 } catch (IOException e) {
109 processingEnv.getMessager().printMessage(isBug367599(e) ? Kind.NOTE : Kind.ERROR, e.getMessage(), serviceProvider);
110 }
111 }
112
113 /**
114 * Determines if a given exception is (most likely) caused by
115 * <a href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=367599">Bug 367599</a>.
116 */
117 public static boolean isBug367599(Throwable t) {
118 if (t instanceof FilerException) {
119 for (StackTraceElement ste : t.getStackTrace()) {
120 if (ste.toString().contains("org.eclipse.jdt.internal.apt.pluggable.core.filer.IdeFilerImpl.create")) {
121 // See: https://bugs.eclipse.org/bugs/show_bug.cgi?id=367599
122 return true;
123 }
124 }
125 }
126 if (t.getCause() != null) {
127 return isBug367599(t.getCause());
128 }
129 return false;
130 }
131
132 @Override
133 public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
134 if (roundEnv.processingOver()) {
135 return true;
136 }
137
138 for (Element element : roundEnv.getElementsAnnotatedWith(ServiceProvider.class)) {
139 assert element.getKind().isClass();
140 processElement((TypeElement) element);
141 }
142
143 return true;
144 }
145 }