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

samples/javacastcounter.js@2f1b9f4daec1 (annotated)

samples/javacastcounter.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

 /*
  * 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.
  */
 // Usage: jjs javacastcounter.js -- <.java files>
 // This example demonstrates Nashorn Java.extend API
 // to subclass a Java class from script.
 // This example uses Javac Compiler and Tree API
 // to list type casts used in java source files.
 if (arguments.length == 0) {
     print("Usage: jjs javacastcounter.js -- <.java files>");
     exit(1);
 }
 // Java types used
 var ToolProvider = Java.type("javax.tools.ToolProvider");
 var TreeScanner = Java.type("com.sun.source.util.TreeScanner");
 var Trees = Java.type("com.sun.source.util.Trees");
 var StringArray = Java.type("java.lang.String[]");
 // 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(arguments, StringArray));
 // create a new compilation task
 var task = compiler.getTask(null, fileMgr, null, null, null, compUnits);
 // SourcePositions object to get positions of AST nodes
 var sourcePositions = Trees.instance(task).sourcePositions;
 // Subclass TreeScanner class
 var CastCounter = Java.extend(TreeScanner);
 var counter = new CastCounter() {
     // current CompilationUnitTree
     compUnit: null,
     // current LineMap (pos -> line, column)
     lineMap: null,
     // current compilation unit's file name
     fileName: null,
     // overrides of TreeScanner methods
     visitCompilationUnit: function(node, p) {
         // capture info about current Compilation unit
         this.compUnit = node;
         this.lineMap = node.lineMap;
         this.fileName = node.sourceFile.name;
         // Using Java.super API to call super class method here
         return Java.super(counter).visitCompilationUnit(node, p);
     },
     visitTypeCast: function(node, p) {
         // print information on this type cast node
         var pos = sourcePositions.getStartPosition(this.compUnit, node);
         var line = this.lineMap.getLineNumber(pos);
         var col = this.lineMap.getColumnNumber(pos);
         print(node + " @ " + this.fileName + ":" + line + ":" + col);
         // count one more type cast
         return 1;
     },
     reduce: function(r1, r2) {
         return (r1 == null ? 0 : r1) + (r2 == null ? 0 : r2);
     }
 };
 // print total number of type cast nodes seen
 print("Total casts:", counter.scan(task.parse(), null));