1 /* 2 * Copyright (c) 2006, 2013, 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.source.util; 27 28 import java.util.Iterator; 29 30 import com.sun.source.tree.*; 31 32 /** 33 * A path of tree nodes, typically used to represent the sequence of ancestor 34 * nodes of a tree node up to the top level CompilationUnitTree node. 35 * 36 * @author Jonathan Gibbons 37 * @since 1.6 38 */ 39 @jdk.Exported 40 public class TreePath implements Iterable<Tree> { 41 /** 42 * Gets a tree path for a tree node within a compilation unit. 43 * @return null if the node is not found 44 */ 45 public static TreePath getPath(CompilationUnitTree unit, Tree target) { 46 return getPath(new TreePath(unit), target); 47 } 48 49 /** 50 * Gets a tree path for a tree node within a subtree identified by a TreePath object. 51 * @return null if the node is not found 52 */ 53 public static TreePath getPath(TreePath path, Tree target) { 54 path.getClass(); 55 target.getClass(); 56 57 class Result extends Error { 58 static final long serialVersionUID = -5942088234594905625L; 59 TreePath path; 60 Result(TreePath path) { 61 this.path = path; 62 } 63 } 64 65 class PathFinder extends TreePathScanner<TreePath,Tree> { 66 public TreePath scan(Tree tree, Tree target) { 67 if (tree == target) { 68 throw new Result(new TreePath(getCurrentPath(), target)); 69 } 70 return super.scan(tree, target); 71 } 72 } 73 74 if (path.getLeaf() == target) { 75 return path; 76 } 77 78 try { 79 new PathFinder().scan(path, target); 80 } catch (Result result) { 81 return result.path; 82 } 83 return null; 84 } 85 86 /** 87 * Creates a TreePath for a root node. 88 */ 89 public TreePath(CompilationUnitTree t) { 90 this(null, t); 91 } 92 93 /** 94 * Creates a TreePath for a child node. 95 */ 96 public TreePath(TreePath p, Tree t) { 97 if (t.getKind() == Tree.Kind.COMPILATION_UNIT) { 98 compilationUnit = (CompilationUnitTree) t; 99 parent = null; 100 } 101 else { 102 compilationUnit = p.compilationUnit; 103 parent = p; 104 } 105 leaf = t; 106 } 107 /** 108 * Get the compilation unit associated with this path. 109 */ 110 public CompilationUnitTree getCompilationUnit() { 111 return compilationUnit; 112 } 113 114 /** 115 * Get the leaf node for this path. 116 */ 117 public Tree getLeaf() { 118 return leaf; 119 } 120 121 /** 122 * Get the path for the enclosing node, or null if there is no enclosing node. 123 */ 124 public TreePath getParentPath() { 125 return parent; 126 } 127 128 /** 129 * Iterates from leaves to root. 130 */ 131 @Override 132 public Iterator<Tree> iterator() { 133 return new Iterator<Tree>() { 134 @Override 135 public boolean hasNext() { 136 return next != null; 137 } 138 139 @Override 140 public Tree next() { 141 Tree t = next.leaf; 142 next = next.parent; 143 return t; 144 } 145 146 @Override 147 public void remove() { 148 throw new UnsupportedOperationException(); 149 } 150 151 private TreePath next = TreePath.this; 152 }; 153 } 154 155 private CompilationUnitTree compilationUnit; 156 private Tree leaf; 157 private TreePath parent; 158 }