jdk8-mips64-public/nashorn: samples/javaastviewer.js@2f1b9f4daec1 (annotated)

samples/javaastviewer.js@2f1b9f4daec1 (annotated)

samples/javaastviewer.js

Fri, 05 Jun 2015 12:38:53 +0200

author: mhaupt
date: Fri, 05 Jun 2015 12:38:53 +0200
changeset 1398: 2f1b9f4daec1
parent 962: ac62e33a99b0
permissions: -rw-r--r--

8080087: Nashorn $ENV.PWD is originally undefined
Summary: On Windows, the PWD environment variable does not exist and cannot be imported in scripting mode, so it is set explicitly.
Reviewed-by: lagergren, sundar

 #// Usage: jjs -fx javaastviewer.js -- <.java files>
 /*
  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  *   - Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  *
  *   - Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
  *     documentation and/or other materials provided with the distribution.
  *
  *   - Neither the name of Oracle nor the names of its
  *     contributors may be used to endorse or promote products derived
  *     from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 // This example demonstrates Java subclassing by Java.extend
 // and javac Compiler and Tree API. This example also uses
 // -fx and javafx TreeView to visualize Java AST as TreeView
 if (!$OPTIONS._fx || arguments.length == 0) {
     print("Usage: jjs -fx javaastviewer.js -- <.java files>");
     exit(1);
 }
 // Java types used
 var Enum = Java.type("java.lang.Enum");
 var HashSet  = Java.type("java.util.HashSet");
 var Name = Java.type("javax.lang.model.element.Name");
 var List = Java.type("java.util.List");
 var Set  = Java.type("java.util.Set");
 var SimpleTreeVisitor = Java.type("com.sun.source.util.SimpleTreeVisitor");
 var StringArray = Java.type("java.lang.String[]");
 var ToolProvider = Java.type("javax.tools.ToolProvider");
 var Tree = Java.type("com.sun.source.tree.Tree");
 function javaASTToScriptObject(args) {
     // properties ignored (javac implementation class properties) in AST view.
     // may not be exhaustive - any getAbc would become "abc" property or
     // public field becomes a property of same name.
     var ignoredProps = new HashSet();
     for each (var word in
         ['extending', 'implementing', 'init', 'mods', 'clazz', 'defs',
          'expr', 'tag', 'preferredPosition', 'qualid', 'recvparam',
          'restype', 'params', 'startPosition', 'thrown',
          'tree', 'typarams', 'typetag', 'vartype']) {
         ignoredProps.add(word);
     }
     // get the system compiler tool
     var compiler = ToolProvider.systemJavaCompiler;
     // get standard file manager
     var fileMgr = compiler.getStandardFileManager(null, null, null);
     // make a list of compilation unit from command line argument file names
     // Using Java.to convert script array (arguments) to a Java String[]
     var compUnits = fileMgr.getJavaFileObjects(Java.to(args, StringArray));
     // create a new compilation task
     var task = compiler.getTask(null, fileMgr, null, null, null, compUnits);
     // subclass SimpleTreeVisitor - converts Java AST node to
     // a simple script object by walking through it
     var ConverterVisitor = Java.extend(SimpleTreeVisitor);
     var visitor = new ConverterVisitor() {
         // convert java AST node to a friendly script object
         // which can be viewed. Every node ends up in defaultAction
         // method of SimpleTreeVisitor method.
         defaultAction: function (node, p) {
             var resultObj = {};
             // Nashorn does not iterate properties and methods of Java objects
             // But, we can bind properties of any object (including java objects)
             // to a script object and iterate it!
             var obj = {};
             Object.bindProperties(obj, node);
             // we don't want every property, method of java object
             for (var prop in obj) {
                 var val = obj[prop];
                 var type = typeof val;
                 // ignore 'method' members
                 if (type == 'function' || type == 'undefined') {
                     continue;
                 }
                 // ignore properties from Javac implementation
                 // classes - hack by name!!
                 if (ignoredProps.contains(prop)) {
                     continue;
                 }
                 // subtree - recurse it
                 if (val instanceof Tree) {
                     resultObj[prop] = visitor.visit(val, p);
                 } else if (val instanceof List) {
                     // List of trees - recurse each and make an array
                     var len = val.size();
                     if (len != 0) {
                         var arr = [];
                         for (var j = 0; j < len; j++) {
                             var e = val[j];
                             if (e instanceof Tree) {
                                 arr.push(visitor.visit(e, p));
                             }
                         }
                         resultObj[prop] = arr;
                     }
                 } else if (val instanceof Set) {
                     // Set - used for modifier flags
                     // make array
                     var len = val.size();
                     if (len != 0) {
                         var arr = [];
                         for each (var e in val) {
                             if (e instanceof Enum || typeof e == 'string') {
                                 arr.push(e.toString());
                             }
                         }
                         resultObj[prop] = arr;
                     }
                 } else if (val instanceof Enum || val instanceof Name) {
                     // make string for any Enum or Name
                     resultObj[prop] = val.toString();
                 } else if (type != 'object') {
                     // primitives 'as is'
                     resultObj[prop] = val;
                 }
             }
             return resultObj;
         }
     }
     // top level object with one property for each compilation unit
     var scriptObj = {};
     for each (var cu in task.parse()) {
         scriptObj[cu.sourceFile.name] = cu.accept(visitor, null);
     }
     return scriptObj;
 }
 // JavaFX classes used
 var StackPane = Java.type("javafx.scene.layout.StackPane");
 var Scene     = Java.type("javafx.scene.Scene");
 var TreeItem  = Java.type("javafx.scene.control.TreeItem");
 var TreeView  = Java.type("javafx.scene.control.TreeView");
 // Create a javafx TreeItem to view a script object
 function treeItemForObject(obj, name) {
     var item = new TreeItem(name);
     for (var prop in obj) {
        var node = obj[prop];
        if (typeof node == 'object') {
            if (node == null) {
                // skip nulls
                continue;
            }
            var subitem = treeItemForObject(node, prop);
        } else {
            var subitem = new TreeItem(prop + ": " + node);
        }
        item.children.add(subitem);
     }
     item.expanded = true;
     return item;
 }
 var commandArgs = arguments;
 // JavaFX start method
 function start(stage) {
     var obj = javaASTToScriptObject(commandArgs);
     stage.title = "Java AST Viewer"
     var rootItem = treeItemForObject(obj, "AST");
     rootItem.expanded = true;
     var tree = new TreeView(rootItem);
     var root = new StackPane();
     root.children.add(tree);
     stage.scene = new Scene(root, 300, 450);
     stage.show();
 }