jdk8-mips64-public/nashorn: samples/exceptionswallow.js@09abd795d1d1 (annotated)

samples/exceptionswallow.js@09abd795d1d1 (annotated)

samples/exceptionswallow.js

Wed, 16 Mar 2016 00:10:12 -0700

author: asaha
date: Wed, 16 Mar 2016 00:10:12 -0700
changeset 1746: 09abd795d1d1
parent 1531: ab48ce00c634
permissions: -rw-r--r--

Added tag jdk8u77-b01 for changeset 678b645aa10a

 #// Usage: jjs exceptionswallow.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.
  */
 // This example demonstrates Java subclassing by Java.extend
 // and javac Compiler and Tree API. This example looks for
 // empty catch blocks ("exception swallow") and reports those.
 if (arguments.length == 0) {
     print("Usage: jjs exceptionswallow.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 Tree = Java.type("com.sun.source.tree.Tree");
 var EmptyStatementTree = Java.type("com.sun.source.tree.EmptyStatementTree");
 var Trees = Java.type("com.sun.source.util.Trees");
 var TreeScanner = Java.type("com.sun.source.util.TreeScanner");
 // printEmptyCatch
 function printEmptyCatch() {
     // 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);
     // SourcePositions object to get positions of AST nodes
     var sourcePositions = Trees.instance(task).sourcePositions;
     // subclass SimpleTreeVisitor - to print empty catch
     var EmptyCatchFinder = Java.extend(TreeScanner);
     function hasOnlyEmptyStats(stats) {
         var itr = stats.iterator();
         while (itr.hasNext()) {
             if (! (itr.next() instanceof EmptyStatementTree)) {
                 return false;
             }
         }
         return true;
     }
     var visitor = new EmptyCatchFinder() {
         // 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(visitor).visitCompilationUnit(node, p);
         },
         visitCatch: function (node, p) {
             var stats = node.block.statements;
             if (stats.empty || hasOnlyEmptyStats(stats)) {
                 // print information on this empty catch
                 var pos = sourcePositions.getStartPosition(this.compUnit, node);
                 var line = this.lineMap.getLineNumber(pos);
                 var col = this.lineMap.getColumnNumber(pos);
                 print("Exception swallow" + " @ " + this.fileName + ":" + line + ":" + col);
                 // print(node);
             }
         }
     }
     for each (var cu in task.parse()) {
         cu.accept(visitor, null);
     }
 }
 // for each ".java" file in directory (recursively) and check it!
 function main(dir) {
     Files.walk(dir.toPath()).
       forEach(function(p) {
         var name = p.toFile().absolutePath;
         if (name.endsWith(".java")) {
             try {
                 printEmptyCatch(p.toFile().getAbsolutePath());
             } catch (e) {
                 print(e);
             }
         }
       });
 }
 main(new File(arguments[0]));