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]));