8152771: NPE accessing comments on module declarations

Reviewed-by: jjg

langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/model/JavacElements.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2016, 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
@@ -629,10 +629,18 @@ public class JavacElements implements Elements {
      */
     private Env<AttrContext> getEnterEnv(Symbol sym) {
         // Get enclosing class of sym, or sym itself if it is a class
-        // or package.
-        TypeSymbol ts = (sym.kind != PCK)
-                        ? sym.enclClass()
-                        : (PackageSymbol) sym;
+        // package, or module.
+        TypeSymbol ts = null;
+        switch (sym.kind) {
+            case PCK:
+                ts = (PackageSymbol)sym;
+                break;
+            case MDL:
+                ts = (ModuleSymbol)sym;
+                break;
+            default:
+                ts = sym.enclClass();
+        }
         return (ts != null)
                 ? enter.getEnv(ts)
                 : null;

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

@@ -615,6 +615,10 @@ public class TreeInfo {
                 if (that.packge == sym) result = that;
                 else super.visitTopLevel(that);
             }
+            public void visitModuleDef(JCModuleDecl that) {
+                if (that.sym == sym) result = that;
+                // no need to scan within module declaration
+            }
             public void visitPackageDef(JCPackageDecl that) {
                 if (that.packge == sym) result = that;
                 else super.visitPackageDef(that);

langtools/test/tools/javac/modules/ModuleInfoTreeAccess.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2016, 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 8152771
+ * @summary test tree access of module declarations
+ * @library /tools/lib
+ * @modules
+ *      jdk.compiler/com.sun.tools.javac.api
+ *      jdk.compiler/com.sun.tools.javac.main
+ *      jdk.jdeps/com.sun.tools.javap
+ * @build toolbox.ToolBox ModuleTestBase
+ * @run main ModuleInfoTreeAccess
+ */
+
+import java.nio.file.Path;
+
+import javax.lang.model.element.ModuleElement;
+import javax.tools.JavaCompiler;
+import javax.tools.JavaFileObject;
+import javax.tools.StandardJavaFileManager;
+import javax.tools.ToolProvider;
+
+import com.sun.source.doctree.DocCommentTree;
+import com.sun.source.util.JavacTask;
+import com.sun.source.util.TreePath;
+import com.sun.tools.javac.api.JavacTrees;
+
+import toolbox.ToolBox;
+
+public class ModuleInfoTreeAccess extends ModuleTestBase {
+    public static void main(String... args) throws Exception {
+        ModuleInfoTreeAccess t = new ModuleInfoTreeAccess();
+        t.runTests();
+    }
+
+    private void assertNotNull(String prefix, Object actual) {
+        if (actual == null) {
+            throw new AssertionError(prefix + ": unexpected null! ");
+        }
+    }
+
+    @Test
+    void testTreePathForModuleDecl(Path base) throws Exception {
+
+        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
+        try (StandardJavaFileManager fm = compiler.getStandardFileManager(null, null, null)) {
+            Path src = base.resolve("src");
+            tb.writeJavaFiles(src, "/** Test module */ module m1 {}");
+
+            Iterable<? extends JavaFileObject> files = fm.getJavaFileObjects(findJavaFiles(src));
+            JavacTask task = (JavacTask) compiler.getTask(null, fm, null, null, null, files);
+
+            task.analyze();
+            JavacTrees trees = JavacTrees.instance(task);
+            ModuleElement mdle = (ModuleElement) task.getElements().getModuleElement("m1");
+
+            TreePath path = trees.getPath(mdle);
+            assertNotNull("path", path);
+
+            ModuleElement mdle1 = (ModuleElement) trees.getElement(path);
+            assertNotNull("mdle1", mdle1);
+
+            DocCommentTree docCommentTree = trees.getDocCommentTree(mdle);
+            assertNotNull("docCommentTree", docCommentTree);
+        }
+    }
+}