1 /* 2 * Copyright (c) 2006, 2014, 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 import java.util.Objects; 30 31 import com.sun.source.tree.*; 32 33 /** 34 * A path of tree nodes, typically used to represent the sequence of ancestor 35 * nodes of a tree node up to the top level CompilationUnitTree node. 36 * 37 * @author Jonathan Gibbons 38 * @since 1.6 39 */ 40 public class TreePath implements Iterable<Tree> { 41 /** 42 * Returns a tree path for a tree node within a compilation unit, 43 * or {@code null} if the node is not found. 44 * @param unit the compilation unit to search 45 * @param target the node to locate 46 * @return the tree path 47 */ 48 public static TreePath getPath(CompilationUnitTree unit, Tree target) { 49 return getPath(new TreePath(unit), target); 50 } 51 52 /** 53 * Returns a tree path for a tree node within a subtree identified by a TreePath object. 54 * Returns {@code null} if the node is not found. 55 * @param path the path in which to search 56 * @param target the node to locate 57 * @return the tree path of the target node 58 */ 59 public static TreePath getPath(TreePath path, Tree target) { 60 Objects.requireNonNull(path); 61 Objects.requireNonNull(target); 62 63 class Result extends Error { 64 static final long serialVersionUID = -5942088234594905625L; 65 TreePath path; 66 Result(TreePath path) { 67 this.path = path; 68 } 69 } 70 71 class PathFinder extends TreePathScanner<TreePath,Tree> { 72 public TreePath scan(Tree tree, Tree target) { 73 if (tree == target) { 74 throw new Result(new TreePath(getCurrentPath(), target)); 75 } 76 return super.scan(tree, target); 77 } 78 } 79 80 if (path.getLeaf() == target) { 81 return path; 82 } 83 84 try { 85 new PathFinder().scan(path, target); 86 } catch (Result result) { 87 return result.path; 88 } 89 return null; 90 } 91 92 /** 93 * Creates a TreePath for a root node. 94 * @param node the root node 95 */ 96 public TreePath(CompilationUnitTree node) { 97 this(null, node); 98 } 99 100 /** 101 * Creates a TreePath for a child node. 102 * @param path the parent path 103 * @param tree the child node 104 */ 105 public TreePath(TreePath path, Tree tree) { 106 if (tree.getKind() == Tree.Kind.COMPILATION_UNIT) { 107 compilationUnit = (CompilationUnitTree) tree; 108 parent = null; 109 } 110 else { 111 compilationUnit = path.compilationUnit; 112 parent = path; 113 } 114 leaf = tree; 115 } 116 /** 117 * Returns the compilation unit associated with this path. 118 * @return the compilation unit 119 */ 120 public CompilationUnitTree getCompilationUnit() { 121 return compilationUnit; 122 } 123 124 /** 125 * Returns the leaf node for this path. 126 * @return the leaf node 127 */ 128 public Tree getLeaf() { 129 return leaf; 130 } 131 132 /** 133 * Returns the path for the enclosing node, or {@code null} if there is no enclosing node. 134 * @return the path for the enclosing node 135 */ 136 public TreePath getParentPath() { 137 return parent; 138 } 139 140 /** 141 * Iterates from leaves to root. 142 */ 143 @Override 144 public Iterator<Tree> iterator() { 145 return new Iterator<Tree>() { 146 @Override 147 public boolean hasNext() { 148 return next != null; 149 } 150 151 @Override 152 public Tree next() { 153 Tree t = next.leaf; 154 next = next.parent; 155 return t; 156 } 157 158 @Override 159 public void remove() { 160 throw new UnsupportedOperationException(); 161 } 162 163 private TreePath next = TreePath.this; 164 }; 165 } 166 167 private CompilationUnitTree compilationUnit; 168 private Tree leaf; 169 private TreePath parent; 170 }