8176470: javac Pretty printer should include doc comment for modules

Reviewed-by: vromero

langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/tree/Pretty.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 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
@@ -442,6 +442,7 @@ public class Pretty extends JCTree.Visitor {
     @Override
     public void visitModuleDef(JCModuleDecl tree) {
         try {
+            printDocComment(tree);
             printAnnotations(tree.mods.annotations);
             if (tree.getModuleType() == ModuleKind.OPEN) {
                 print("open ");

langtools/test/tools/javac/tree/TestPrettyDocComment.java

@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 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.
+ *
+ * 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.
+ */
+
+/*
+ * @test
+ * @bug 8176470
+ * @summary javac Pretty printer should include doc comment for modules
+ * @modules jdk.compiler
+ * @library /tools/lib
+ * @build toolbox.TestRunner
+ * @run main TestPrettyDocComment
+ */
+
+import java.io.IOException;
+import java.io.StringWriter;
+import java.net.URI;
+import java.util.List;
+
+import javax.tools.JavaFileObject;
+import javax.tools.JavaCompiler;
+import javax.tools.SimpleJavaFileObject;
+import javax.tools.ToolProvider;
+
+import com.sun.source.tree.CompilationUnitTree;
+import com.sun.source.util.JavacTask;
+
+import toolbox.TestRunner;
+
+public class TestPrettyDocComment extends TestRunner {
+
+    public static void main(String... args) throws Exception {
+        TestPrettyDocComment t = new TestPrettyDocComment();
+        t.runTests();
+    }
+
+    final JavaCompiler tool = ToolProvider.getSystemJavaCompiler();
+
+    TestPrettyDocComment() {
+        super(System.err);
+    }
+
+    @Test
+    public void testModule() throws IOException {
+        test("module-info.java", "/** This is a module. */ module m { }");
+    }
+
+    @Test
+    public void testPackage() throws IOException {
+        test("package-info.java", "/** This is a package. */ package p;");
+    }
+
+    @Test
+    public void testClass() throws IOException {
+        test("C.java", "/** This is a class. */ class C { }");
+    }
+
+    @Test
+    public void testField() throws IOException {
+        test("C.java", "class C { /** This is a field. */ int f; }");
+    }
+
+    @Test
+    public void testMethod() throws IOException {
+        test("C.java", "class C { /** This is a method. */ void m() { } }");
+    }
+
+    void test(String name, String source) throws IOException {
+        JavaFileObject fo = new JavaSource(name, source);
+        StringWriter log = new StringWriter();
+        JavacTask t = (JavacTask) tool.getTask(log, null, null, null, null, List.of(fo));
+        Iterable<? extends CompilationUnitTree> trees = t.parse();
+        String out = log.toString();
+        if (!out.isEmpty()) {
+            System.err.println(log);
+        }
+        String pretty = trees.iterator().next().toString();
+        System.err.println("Pretty: <<<");
+        System.err.println(pretty);
+        System.err.println(">>>");
+
+        String commentText = source.replaceAll(".*\\Q/**\\E (.*) \\Q*/\\E.*", "$1");
+        if (!pretty.contains(commentText)) {
+            error("expected text not found: " + commentText);
+        }
+    }
+
+    static class JavaSource extends SimpleJavaFileObject {
+        final String source;
+
+        public JavaSource(String name, String source) {
+            super(URI.create("myfo:/" + name), JavaFileObject.Kind.SOURCE);
+            this.source = source;
+        }
+
+        @Override
+        public CharSequence getCharContent(boolean ignoreEncodingErrors) {
+            return source;
+        }
+    }
+}