jdk8-mips64-public/nashorn: samples/resourcetrysuggester.js@d0fba38a0705 (annotated)

samples/resourcetrysuggester.js@d0fba38a0705 (annotated)

samples/resourcetrysuggester.js

Tue, 22 Mar 2016 21:31:52 -0700

author: asaha
date: Tue, 22 Mar 2016 21:31:52 -0700
changeset 1810: d0fba38a0705
parent 1531: ab48ce00c634
permissions: -rw-r--r--

Added tag jdk8u92-b13 for changeset e2294411edbd

 #// Usage: jjs resourcetrysuggester.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
 // finally clauses with "close" call and suggests "resource try"!
 if (arguments.length == 0) {
     print("Usage: jjs resourcetrysuggester.js -- <directory>");
     exit(1);
 }
 // Java types used
 var ExpressionStatementTree = Java.type("com.sun.source.tree.ExpressionStatementTree");
 var File = Java.type("java.io.File");
 var Files = Java.type("java.nio.file.Files");
 var MemberSelectTree = Java.type("com.sun.source.tree.MemberSelectTree");
 var MethodInvocationTree = Java.type("com.sun.source.tree.MethodInvocationTree");
 var StringArray = Java.type("java.lang.String[]");
 var ToolProvider = Java.type("javax.tools.ToolProvider");
 var Tree = Java.type("com.sun.source.tree.Tree");
 var Trees = Java.type("com.sun.source.util.Trees");
 var TreeScanner = Java.type("com.sun.source.util.TreeScanner");
 // resourceTrySuggestions
 function resourceTrySuggestions() {
     // 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 resource try suggestions
     var ResourceTrySuggester = Java.extend(TreeScanner);
     function hasOnlyEmptyStats(stats) {
         var itr = stats.iterator();
         while (itr.hasNext()) {
             if (! (itr.next() instanceof EmptyStatementTree)) {
                 return false;
             }
         }
         return true;
     }
     // does the given statement list has an expression statement which
     // calls "close" method (don't worry about types - just crude one will do)
     function hasCloseCall(stats) {
         var itr = stats.iterator();
         while (itr.hasNext()) {
             var stat = itr.next();
             if (stat instanceof ExpressionStatementTree) {
                 var expr = stat.expression;
                 if (expr instanceof MethodInvocationTree) {
                     var method = expr.methodSelect;
                     if (method instanceof MemberSelectTree) {
                         return method.identifier.toString().equals("close");
                     }
                 }
             }
         }
         return false;
     }
     var visitor = new ResourceTrySuggester() {
         // 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);
         },
         visitTry: function (node, p) {
             var finallyBlk = node.finallyBlock;
             if (finallyBlk != null && hasCloseCall(finallyBlk.statements)) {
                 var pos = sourcePositions.getStartPosition(this.compUnit, node);
                 var line = this.lineMap.getLineNumber(pos);
                 var col = this.lineMap.getColumnNumber(pos);
                 print("Consider resource try statement " + " @ " + 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 {
                 resourceTrySuggestions(p.toFile().getAbsolutePath());
             } catch (e) {
                 print(e);
             }
         }
       });
 }
 main(new File(arguments[0]));