1 #// Usage: jjs resourcetrysuggester.js -- <directory>

     2 

     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  */

    33 

    34 // This example demonstrates Java subclassing by Java.extend

    35 // and javac Compiler and Tree API. This example looks for

    36 // finally clauses with "close" call and suggests "resource try"!

    37 

    38 if (arguments.length == 0) {

    39     print("Usage: jjs resourcetrysuggester.js -- <directory>");

    40     exit(1);

    41 }

    42  

    43 // Java types used

    44 var ExpressionStatementTree = Java.type("com.sun.source.tree.ExpressionStatementTree");

    45 var File = Java.type("java.io.File");

    46 var Files = Java.type("java.nio.file.Files");

    47 var MemberSelectTree = Java.type("com.sun.source.tree.MemberSelectTree");

    48 var MethodInvocationTree = Java.type("com.sun.source.tree.MethodInvocationTree");

    49 var StringArray = Java.type("java.lang.String[]");

    50 var ToolProvider = Java.type("javax.tools.ToolProvider");

    51 var Tree = Java.type("com.sun.source.tree.Tree");

    52 var Trees = Java.type("com.sun.source.util.Trees");

    53 var TreeScanner = Java.type("com.sun.source.util.TreeScanner");

    54 

    55 // resourceTrySuggestions

    56 

    57 function resourceTrySuggestions() {

    58     // get the system compiler tool

    59     var compiler = ToolProvider.systemJavaCompiler;

    60     // get standard file manager

    61     var fileMgr = compiler.getStandardFileManager(null, null, null);

    62     // Using Java.to convert script array (arguments) to a Java String[]

    63     var compUnits = fileMgr.getJavaFileObjects(

    64         Java.to(arguments, StringArray));

    65     // create a new compilation task

    66     var task = compiler.getTask(null, fileMgr, null, null, null, compUnits);

    67 

    68     // SourcePositions object to get positions of AST nodes

    69     var sourcePositions = Trees.instance(task).sourcePositions;

    70 

    71     // subclass SimpleTreeVisitor - to print resource try suggestions

    72     var ResourceTrySuggester = Java.extend(TreeScanner);

    73    

    74     function hasOnlyEmptyStats(stats) {

    75         var itr = stats.iterator();

    76         while (itr.hasNext()) {

    77             if (! (itr.next() instanceof EmptyStatementTree)) {

    78                 return false;

    79             }

    80         }

    81 

    82         return true;

    83     }

    84 

    85     // does the given statement list has an expression statement which

    86     // calls "close" method (don't worry about types - just crude one will do)

    87     function hasCloseCall(stats) {

    88         var itr = stats.iterator();

    89         while (itr.hasNext()) {

    90             var stat = itr.next();

    91             if (stat instanceof ExpressionStatementTree) {

    92                 var expr = stat.expression;

    93                 if (expr instanceof MethodInvocationTree) {

    94                     var method = expr.methodSelect;

    95                     if (method instanceof MemberSelectTree) {

    96                         return method.identifier.toString().equals("close");

    97                     }

    98                 }

    99             }

   100         }

   101         return false;

   102     }

   103  

   104     var visitor = new ResourceTrySuggester() {

   105         // current CompilationUnitTree

   106         compUnit: null,

   107         // current LineMap (pos -> line, column)

   108         lineMap: null,

   109         // current compilation unit's file name

   110         fileName: null,

   111 

   112         // overrides of TreeScanner methods

   113 

   114         visitCompilationUnit: function(node, p) {

   115             // capture info about current Compilation unit

   116             this.compUnit = node;

   117             this.lineMap = node.lineMap;

   118             this.fileName = node.sourceFile.name;

   119 

   120             // Using Java.super API to call super class method here

   121             return Java.super(visitor).visitCompilationUnit(node, p);

   122         },

   123 

   124         visitTry: function (node, p) {

   125             var finallyBlk = node.finallyBlock;

   126             if (finallyBlk != null && hasCloseCall(finallyBlk.statements)) {

   127                 var pos = sourcePositions.getStartPosition(this.compUnit, node);

   128                 var line = this.lineMap.getLineNumber(pos);

   129                 var col = this.lineMap.getColumnNumber(pos);

   130                 print("Consider resource try statement " + " @ " + this.fileName + ":" + line + ":" + col);

   131                 // print(node);

   132             }

   133         }

   134     }

   135  

   136     for each (var cu in task.parse()) {

   137         cu.accept(visitor, null);

   138     }

   139 }

   140  

   141 // for each ".java" file in directory (recursively) and check it!

   142 function main(dir) {

   143     Files.walk(dir.toPath()).

   144       forEach(function(p) {

   145         var name = p.toFile().absolutePath;

   146         if (name.endsWith(".java")) {

   147             try {

   148                 resourceTrySuggestions(p.toFile().getAbsolutePath());

   149             } catch (e) {

   150                 print(e);

   151             }

   152         }

   153       });

   154 }

   155  

   156 main(new File(arguments[0]));