Mon, 09 Nov 2015 13:45:10 -0800
Merge
1 #// Usage: jjs getclassnpe.js -- <directory>
3 /*
4 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * - Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *
13 * - Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * - Neither the name of Oracle nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
22 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
23 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
25 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
28 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
34 /*
35 * java.lang.Object.getClass() is sometimes used to do null check. This
36 * obfuscating Object.getClass() check relies on non-related intrinsic
37 * performance, which is potentially not available everywhere.
38 * See also http://cr.openjdk.java.net/~shade/scratch/NullChecks.java
39 * This nashorn script checks for such uses in your .java files in the
40 * given directory (recursively).
41 */
43 if (arguments.length == 0) {
44 print("Usage: jjs getclassnpe.js -- <directory>");
45 exit(1);
46 }
48 // Java types used
49 var File = Java.type("java.io.File");
50 var Files = Java.type("java.nio.file.Files");
51 var StringArray = Java.type("java.lang.String[]");
52 var ToolProvider = Java.type("javax.tools.ToolProvider");
53 var MethodInvocationTree = Java.type("com.sun.source.tree.MethodInvocationTree");
54 var TreeScanner = Java.type("com.sun.source.util.TreeScanner");
56 // parse a specific .java file to check if it uses
57 // Object.getClass() for null check.
58 function checkGetClassNPE() {
59 // get the system compiler tool
60 var compiler = ToolProvider.systemJavaCompiler;
61 // get standard file manager
62 var fileMgr = compiler.getStandardFileManager(null, null, null);
63 // Using Java.to convert script array (arguments) to a Java String[]
64 var compUnits = fileMgr.getJavaFileObjects(
65 Java.to(arguments, StringArray));
66 // create a new compilation task
67 var task = compiler.getTask(null, fileMgr, null, null, null, compUnits);
68 // subclass SimpleTreeVisitor - to check for obj.getClass(); statements
69 var GetClassNPEChecker = Java.extend(TreeScanner);
71 var visitor = new GetClassNPEChecker() {
72 lineMap: null,
73 sourceFile: null,
75 // save compilation unit details for reporting
76 visitCompilationUnit: function(node, p) {
77 this.sourceFile = node.sourceFile;
78 this.lineMap = node.lineMap;
79 return Java.super(visitor).visitCompilationUnit(node, p);
80 },
82 // look for "foo.getClass();" expression statements
83 visitExpressionStatement: function(node, p) {
84 var expr = node.expression;
85 if (expr instanceof MethodInvocationTree) {
86 var name = String(expr.methodSelect.identifier);
88 // will match any "getClass" call with zero arguments!
89 if (name == "getClass" && expr.arguments.size() == 0) {
90 print(this.sourceFile.getName()
91 + " @ "
92 + this.lineMap.getLineNumber(node.pos)
93 + ":"
94 + this.lineMap.getColumnNumber(node.pos));
96 print("\t", node);
97 }
98 }
99 }
100 }
102 for each (var cu in task.parse()) {
103 cu.accept(visitor, null);
104 }
105 }
107 // for each ".java" file in the directory (recursively)
108 function main(dir) {
109 Files.walk(dir.toPath()).
110 forEach(function(p) {
111 var name = p.toFile().absolutePath;
112 if (name.endsWith(".java")) {
113 try {
114 checkGetClassNPE(p.toFile().getAbsolutePath());
115 } catch (e) {
116 print(e);
117 }
118 }
119 });
120 }
122 main(new File(arguments[0]));