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

samples/getclassnpe.js@2f1b9f4daec1 (annotated)

samples/getclassnpe.js

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

author: mhaupt
date: Fri, 05 Jun 2015 12:38:53 +0200
changeset 1398: 2f1b9f4daec1
parent 1232: 09bd5b8abcba
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 getclassnpe.js -- <directory>
 /*
  * Copyright (c) 2015, 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.
  */
 /*
  * java.lang.Object.getClass() is sometimes used to do null check. This
  * obfuscating Object.getClass() check relies on non-related intrinsic
  * performance, which is potentially not available everywhere.
  * See also http://cr.openjdk.java.net/~shade/scratch/NullChecks.java
  * This nashorn script checks for such uses in your .java files in the
  * given directory (recursively).
  */
 if (arguments.length == 0) {
     print("Usage: jjs getclassnpe.js -- <directory>");
     exit(1);
 }
 // Java types used
 var File = Java.type("java.io.File");
 var Files = Java.type("java.nio.file.Files");
 var StringArray = Java.type("java.lang.String[]");
 var ToolProvider = Java.type("javax.tools.ToolProvider");
 var MethodInvocationTree = Java.type("com.sun.source.tree.MethodInvocationTree");
 var TreeScanner = Java.type("com.sun.source.util.TreeScanner");
 // parse a specific .java file to check if it uses
 // Object.getClass() for null check.
 function checkGetClassNPE() {
     // get the system compiler tool
     var compiler = ToolProvider.systemJavaCompiler;
     // get standard file manager
     var fileMgr = compiler.getStandardFileManager(null, null, null);
     // 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);
     // subclass SimpleTreeVisitor - to check for obj.getClass(); statements
     var GetClassNPEChecker = Java.extend(TreeScanner);
     var visitor = new GetClassNPEChecker() {
         lineMap: null,
         sourceFile: null,
         // save compilation unit details for reporting
         visitCompilationUnit: function(node, p) {
            this.sourceFile = node.sourceFile;
            this.lineMap = node.lineMap;
            return Java.super(visitor).visitCompilationUnit(node, p);
         },
         // look for "foo.getClass();" expression statements
         visitExpressionStatement: function(node, p) {
             var expr = node.expression;
             if (expr instanceof MethodInvocationTree) {
                 var name = String(expr.methodSelect.identifier);
                 // will match any "getClass" call with zero arguments!
                 if (name == "getClass" && expr.arguments.size() == 0) {
                     print(this.sourceFile.getName()
                      + " @ "
                      + this.lineMap.getLineNumber(node.pos)
                      + ":"
                      + this.lineMap.getColumnNumber(node.pos));
                     print("\t", node);
                 }
             }
         }
     }
     for each (var cu in task.parse()) {
         cu.accept(visitor, null);
     }
 }
 // for each ".java" file in the directory (recursively)
 function main(dir) {
     Files.walk(dir.toPath()).
       forEach(function(p) {
           var name = p.toFile().absolutePath;
           if (name.endsWith(".java")) {
               try {
                   checkGetClassNPE(p.toFile().getAbsolutePath());
               } catch (e) {
                   print(e);
               }
           }
       });
 }
 main(new File(arguments[0]));