1 /*
   2  * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
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  23 
  24 /*
  25  * @test
  26  * @bug 8206986
  27  * @summary Ensure SimpleTreeVisitor.visitSwitchExpression behaves as it should
  28  * @modules jdk.compiler
  29  */
  30 
  31 import java.io.IOException;
  32 import java.io.StringWriter;
  33 import java.net.URI;
  34 import java.util.Arrays;
  35 import java.util.List;
  36 
  37 import javax.tools.*;
  38 
  39 import com.sun.source.tree.CompilationUnitTree;
  40 import com.sun.source.tree.SwitchExpressionTree;
  41 import com.sun.source.tree.Tree;
  42 import com.sun.source.util.JavacTask;
  43 import com.sun.source.util.SimpleTreeVisitor;
  44 import com.sun.source.util.TreePathScanner;
  45 
  46 public class SwitchExpressionSimpleVisitorTest {
  47 
  48     public static void main(String[] args) throws Exception {
  49         new SwitchExpressionSimpleVisitorTest().run();
  50     }
  51 
  52     void run() throws Exception {
  53         String code = "class Test {\n" +
  54                       "    int t(int i) {\n" +
  55                       "         return switch(i) {\n" +
  56                       "              default: break -1;\n" +
  57                       "         }\n" +
  58                       "    }\n" +
  59                       "}\n";
  60         int[] callCount = new int[1];
  61         int[] switchExprNodeCount = new int[1];
  62         new TreePathScanner<Void, Void>() {
  63             @Override
  64             public Void visitSwitchExpression(SwitchExpressionTree node, Void p) {
  65                 node.accept(new SimpleTreeVisitor<Void, Void>() {
  66                     @Override
  67                     protected Void defaultAction(Tree defaultActionNode, Void p) {
  68                         callCount[0]++;
  69                         if (node == defaultActionNode) {
  70                             switchExprNodeCount[0]++;
  71                         }
  72                         return null;
  73                     }
  74                 }, null);
  75                 return super.visitSwitchExpression(node, p);
  76             }
  77         }.scan(parse(code), null);
  78 
  79         if (callCount[0] != 1 || switchExprNodeCount[0] != 1) {
  80             throw new AssertionError("Unexpected counts; callCount=" + callCount[0] +
  81                                      ", switchExprNodeCount=" + switchExprNodeCount[0]);
  82         }
  83     }
  84 
  85     private CompilationUnitTree parse(String code) throws IOException {
  86         final JavaCompiler tool = ToolProvider.getSystemJavaCompiler();
  87         assert tool != null;
  88         DiagnosticListener<JavaFileObject> noErrors = d -> {};
  89 
  90         StringWriter out = new StringWriter();
  91         JavacTask ct = (JavacTask) tool.getTask(out, null, noErrors,
  92             List.of("--enable-preview", "-source", Integer.toString(Runtime.version().feature())), null,
  93             Arrays.asList(new MyFileObject(code)));
  94         return ct.parse().iterator().next();
  95     }
  96 
  97     static class MyFileObject extends SimpleJavaFileObject {
  98         private String text;
  99 
 100         public MyFileObject(String text) {
 101             super(URI.create("myfo:/Test.java"), JavaFileObject.Kind.SOURCE);
 102             this.text = text;
 103         }
 104 
 105         @Override
 106         public CharSequence getCharContent(boolean ignoreEncodingErrors) {
 107             return text;
 108         }
 109     }
 110 }