1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/samples/getclassnpe.js Fri Feb 06 19:28:26 2015 +0530
1.3 @@ -0,0 +1,122 @@
1.4 +#// Usage: jjs getclassnpe.js -- <directory>
1.5 +
1.6 +/*
1.7 + * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
1.8 + *
1.9 + * Redistribution and use in source and binary forms, with or without
1.10 + * modification, are permitted provided that the following conditions
1.11 + * are met:
1.12 + *
1.13 + * - Redistributions of source code must retain the above copyright
1.14 + * notice, this list of conditions and the following disclaimer.
1.15 + *
1.16 + * - Redistributions in binary form must reproduce the above copyright
1.17 + * notice, this list of conditions and the following disclaimer in the
1.18 + * documentation and/or other materials provided with the distribution.
1.19 + *
1.20 + * - Neither the name of Oracle nor the names of its
1.21 + * contributors may be used to endorse or promote products derived
1.22 + * from this software without specific prior written permission.
1.23 + *
1.24 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
1.25 + * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
1.26 + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
1.27 + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
1.28 + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
1.29 + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
1.30 + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
1.31 + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
1.32 + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
1.33 + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
1.34 + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.35 + */
1.36 +
1.37 +/*
1.38 + * java.lang.Object.getClass() is sometimes used to do null check. This
1.39 + * obfuscating Object.getClass() check relies on non-related intrinsic
1.40 + * performance, which is potentially not available everywhere.
1.41 + * See also http://cr.openjdk.java.net/~shade/scratch/NullChecks.java
1.42 + * This nashorn script checks for such uses in your .java files in the
1.43 + * given directory (recursively).
1.44 + */
1.45 +
1.46 +if (arguments.length == 0) {
1.47 + print("Usage: jjs getclassnpe.js -- <directory>");
1.48 + exit(1);
1.49 +}
1.50 +
1.51 +// Java types used
1.52 +var File = Java.type("java.io.File");
1.53 +var Files = Java.type("java.nio.file.Files");
1.54 +var StringArray = Java.type("java.lang.String[]");
1.55 +var ToolProvider = Java.type("javax.tools.ToolProvider");
1.56 +var MethodInvocationTree = Java.type("com.sun.source.tree.MethodInvocationTree");
1.57 +var TreeScanner = Java.type("com.sun.source.util.TreeScanner");
1.58 +
1.59 +// parse a specific .java file to check if it uses
1.60 +// Object.getClass() for null check.
1.61 +function checkGetClassNPE() {
1.62 + // get the system compiler tool
1.63 + var compiler = ToolProvider.systemJavaCompiler;
1.64 + // get standard file manager
1.65 + var fileMgr = compiler.getStandardFileManager(null, null, null);
1.66 + // Using Java.to convert script array (arguments) to a Java String[]
1.67 + var compUnits = fileMgr.getJavaFileObjects(
1.68 + Java.to(arguments, StringArray));
1.69 + // create a new compilation task
1.70 + var task = compiler.getTask(null, fileMgr, null, null, null, compUnits);
1.71 + // subclass SimpleTreeVisitor - to check for obj.getClass(); statements
1.72 + var GetClassNPEChecker = Java.extend(TreeScanner);
1.73 +
1.74 + var visitor = new GetClassNPEChecker() {
1.75 + lineMap: null,
1.76 + sourceFile: null,
1.77 +
1.78 + // save compilation unit details for reporting
1.79 + visitCompilationUnit: function(node, p) {
1.80 + this.sourceFile = node.sourceFile;
1.81 + this.lineMap = node.lineMap;
1.82 + return Java.super(visitor).visitCompilationUnit(node, p);
1.83 + },
1.84 +
1.85 + // look for "foo.getClass();" expression statements
1.86 + visitExpressionStatement: function(node, p) {
1.87 + var expr = node.expression;
1.88 + if (expr instanceof MethodInvocationTree) {
1.89 + var name = String(expr.methodSelect.identifier);
1.90 +
1.91 + // will match any "getClass" call with zero arguments!
1.92 + if (name == "getClass" && expr.arguments.size() == 0) {
1.93 + print(this.sourceFile.getName()
1.94 + + " @ "
1.95 + + this.lineMap.getLineNumber(node.pos)
1.96 + + ":"
1.97 + + this.lineMap.getColumnNumber(node.pos));
1.98 +
1.99 + print("\t", node);
1.100 + }
1.101 + }
1.102 + }
1.103 + }
1.104 +
1.105 + for each (var cu in task.parse()) {
1.106 + cu.accept(visitor, null);
1.107 + }
1.108 +}
1.109 +
1.110 +// for each ".java" file in the directory (recursively)
1.111 +function main(dir) {
1.112 + Files.walk(dir.toPath()).
1.113 + forEach(function(p) {
1.114 + var name = p.toFile().absolutePath;
1.115 + if (name.endsWith(".java")) {
1.116 + try {
1.117 + checkGetClassNPE(p.toFile().getAbsolutePath());
1.118 + } catch (e) {
1.119 + print(e);
1.120 + }
1.121 + }
1.122 + });
1.123 +}
1.124 +
1.125 +main(new File(arguments[0]));
