/*
* Copyright (c) 2013, Oracle and/or its affiliates. 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.
*
* 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package org.graalvm.compiler.serviceprovider.processor;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import javax.annotation.processing.AbstractProcessor;
import javax.annotation.processing.FilerException;
import javax.annotation.processing.RoundEnvironment;
import javax.annotation.processing.SupportedAnnotationTypes;
import javax.lang.model.SourceVersion;
import javax.lang.model.element.Element;
import javax.lang.model.element.TypeElement;
import javax.lang.model.type.MirroredTypeException;
import javax.lang.model.type.TypeMirror;
import javax.tools.Diagnostic.Kind;
import javax.tools.FileObject;
import javax.tools.StandardLocation;
import org.graalvm.compiler.serviceprovider.ServiceProvider;
/**
* Processes classes annotated with {@link ServiceProvider}. For a service defined by {@code S} and
* a class {@code P} implementing the service, this processor generates the file
* {@code META-INF/providers/P} whose contents are a single line containing the fully qualified name
* of {@code S}.
*/
@SupportedAnnotationTypes("org.graalvm.compiler.serviceprovider.ServiceProvider")
public class ServiceProviderProcessor extends AbstractProcessor {
private final Set<TypeElement> processed = new HashSet<>();
private final Map<TypeElement, String> serviceProviders = new HashMap<>();
@Override
public SourceVersion getSupportedSourceVersion() {
return SourceVersion.latest();
}
private boolean verifyAnnotation(TypeMirror serviceInterface, TypeElement serviceProvider) {
if (!processingEnv.getTypeUtils().isSubtype(serviceProvider.asType(), serviceInterface)) {
String msg = String.format("Service provider class %s must implement service interface %s", serviceProvider.getSimpleName(), serviceInterface);
processingEnv.getMessager().printMessage(Kind.ERROR, msg, serviceProvider);
return false;
}
return true;
}
private void processElement(TypeElement serviceProvider) {
if (processed.contains(serviceProvider)) {
return;
}
processed.add(serviceProvider);
ServiceProvider annotation = serviceProvider.getAnnotation(ServiceProvider.class);
if (annotation != null) {
try {
annotation.value();
} catch (MirroredTypeException ex) {
TypeMirror serviceInterface = ex.getTypeMirror();
if (verifyAnnotation(serviceInterface, serviceProvider)) {
if (serviceProvider.getNestingKind().isNested()) {
/*
* This is a simplifying constraint that means we don't have to process the
* qualified name to insert '$' characters at the relevant positions.
*/
String msg = String.format("Service provider class %s must be a top level class", serviceProvider.getSimpleName());
processingEnv.getMessager().printMessage(Kind.ERROR, msg, serviceProvider);
} else {
serviceProviders.put(serviceProvider, ex.getTypeMirror().toString());
}
}
}
}
}
private void writeProviderFile(TypeElement serviceProvider, String interfaceName) {
String filename = "META-INF/providers/" + serviceProvider.getQualifiedName();
try {
FileObject file = processingEnv.getFiler().createResource(StandardLocation.CLASS_OUTPUT, "", filename, serviceProvider);
PrintWriter writer = new PrintWriter(new OutputStreamWriter(file.openOutputStream(), "UTF-8"));
writer.println(interfaceName);
writer.close();
} catch (IOException e) {
processingEnv.getMessager().printMessage(isBug367599(e) ? Kind.NOTE : Kind.ERROR, e.getMessage(), serviceProvider);
}
}
/**
* Determines if a given exception is (most likely) caused by
* <a href="https://bugs.eclipse.org/bugs/show_bug.cgi?id=367599">Bug 367599</a>.
*/
private static boolean isBug367599(Throwable t) {
if (t instanceof FilerException) {
for (StackTraceElement ste : t.getStackTrace()) {
if (ste.toString().contains("org.eclipse.jdt.internal.apt.pluggable.core.filer.IdeFilerImpl.create")) {
// See: https://bugs.eclipse.org/bugs/show_bug.cgi?id=367599
return true;
}
}
}
return t.getCause() != null && isBug367599(t.getCause());
}
@Override
public boolean process(Set<? extends TypeElement> annotations, RoundEnvironment roundEnv) {
if (roundEnv.processingOver()) {
for (Entry<TypeElement, String> e : serviceProviders.entrySet()) {
writeProviderFile(e.getKey(), e.getValue());
}
serviceProviders.clear();
return true;
}
for (Element element : roundEnv.getElementsAnnotatedWith(ServiceProvider.class)) {
assert element.getKind().isClass();
processElement((TypeElement) element);
}
return true;
}
}