--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/jdk/internal/module/ModuleInfoWriter.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,109 @@
+/*
+ * Copyright (c) 2015, 2017, 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. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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 jdk.internal.module;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.lang.module.ModuleDescriptor;
+import java.nio.ByteBuffer;
+import java.util.stream.Stream;
+
+import jdk.internal.org.objectweb.asm.ClassWriter;
+import jdk.internal.org.objectweb.asm.Opcodes;
+
+import static jdk.internal.module.ClassFileAttributes.*;
+import static jdk.internal.module.ClassFileConstants.ACC_MODULE;
+
+/**
+ * Utility class to write a ModuleDescriptor as a module-info.class.
+ */
+
+public final class ModuleInfoWriter {
+
+ private ModuleInfoWriter() { }
+
+ /**
+ * Writes the given module descriptor to a module-info.class file,
+ * returning it in a byte array.
+ */
+ private static byte[] toModuleInfo(ModuleDescriptor md, ModuleTarget target) {
+ ClassWriter cw = new ClassWriter(0);
+ cw.visit(Opcodes.V1_9, ACC_MODULE, "module-info", null, null, null);
+ cw.visitAttribute(new ModuleAttribute(md));
+
+ // for tests: write the ModulePackages attribute when there are packages
+ // that aren't exported or open
+ Stream<String> exported = md.exports().stream()
+ .map(ModuleDescriptor.Exports::source);
+ Stream<String> open = md.opens().stream()
+ .map(ModuleDescriptor.Opens::source);
+ long exportedOrOpen = Stream.concat(exported, open).distinct().count();
+ if (md.packages().size() > exportedOrOpen)
+ cw.visitAttribute(new ModulePackagesAttribute(md.packages()));
+
+ // write ModuleMainClass if the module has a main class
+ md.mainClass().ifPresent(mc -> cw.visitAttribute(new ModuleMainClassAttribute(mc)));
+
+ // write ModuleTarget if there is a target platform
+ if (target != null) {
+ cw.visitAttribute(new ModuleTargetAttribute(target.targetPlatform()));
+ }
+
+ cw.visitEnd();
+ return cw.toByteArray();
+ }
+
+ /**
+ * Writes a module descriptor to the given output stream as a
+ * module-info.class.
+ */
+ public static void write(ModuleDescriptor descriptor,
+ ModuleTarget target,
+ OutputStream out)
+ throws IOException
+ {
+ byte[] bytes = toModuleInfo(descriptor, target);
+ out.write(bytes);
+ }
+
+ /**
+ * Writes a module descriptor to the given output stream as a
+ * module-info.class.
+ */
+ public static void write(ModuleDescriptor descriptor, OutputStream out)
+ throws IOException
+ {
+ write(descriptor, null, out);
+ }
+
+ /**
+ * Returns a {@code ByteBuffer} containing the given module descriptor
+ * in module-info.class format.
+ */
+ public static ByteBuffer toByteBuffer(ModuleDescriptor descriptor) {
+ byte[] bytes = toModuleInfo(descriptor, null);
+ return ByteBuffer.wrap(bytes);
+ }
+}