Mercurial > jdk8-mips64-public > nashorn / file revision

 #// 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]));