1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/classes/com/sun/tools/javac/comp/Env.java Wed Apr 27 01:34:52 2016 +0800
1.3 @@ -0,0 +1,159 @@
1.4 +/*
1.5 + * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation. Oracle designates this
1.11 + * particular file as subject to the "Classpath" exception as provided
1.12 + * by Oracle in the LICENSE file that accompanied this code.
1.13 + *
1.14 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.15 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.16 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.17 + * version 2 for more details (a copy is included in the LICENSE file that
1.18 + * accompanied this code).
1.19 + *
1.20 + * You should have received a copy of the GNU General Public License version
1.21 + * 2 along with this work; if not, write to the Free Software Foundation,
1.22 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.23 + *
1.24 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.25 + * or visit www.oracle.com if you need additional information or have any
1.26 + * questions.
1.27 + */
1.28 +
1.29 +package com.sun.tools.javac.comp;
1.30 +
1.31 +import com.sun.tools.javac.tree.*;
1.32 +import java.util.Iterator;
1.33 +import java.util.NoSuchElementException;
1.34 +
1.35 +/** A class for environments, instances of which are passed as
1.36 + * arguments to tree visitors. Environments refer to important ancestors
1.37 + * of the subtree that's currently visited, such as the enclosing method,
1.38 + * the enclosing class, or the enclosing toplevel node. They also contain
1.39 + * a generic component, represented as a type parameter, to carry further
1.40 + * information specific to individual passes.
1.41 + *
1.42 + * <p><b>This is NOT part of any supported API.
1.43 + * If you write code that depends on this, you do so at your own risk.
1.44 + * This code and its internal interfaces are subject to change or
1.45 + * deletion without notice.</b>
1.46 + */
1.47 +public class Env<A> implements Iterable<Env<A>> {
1.48 +
1.49 + /** The next enclosing environment.
1.50 + */
1.51 + public Env<A> next;
1.52 +
1.53 + /** The environment enclosing the current class.
1.54 + */
1.55 + public Env<A> outer;
1.56 +
1.57 + /** The tree with which this environment is associated.
1.58 + */
1.59 + public JCTree tree;
1.60 +
1.61 + /** The enclosing toplevel tree.
1.62 + */
1.63 + public JCTree.JCCompilationUnit toplevel;
1.64 +
1.65 + /** The next enclosing class definition.
1.66 + */
1.67 + public JCTree.JCClassDecl enclClass;
1.68 +
1.69 + /** The next enclosing method definition.
1.70 + */
1.71 + public JCTree.JCMethodDecl enclMethod;
1.72 +
1.73 + /** A generic field for further information.
1.74 + */
1.75 + public A info;
1.76 +
1.77 + /** Is this an environment for evaluating a base clause?
1.78 + */
1.79 + public boolean baseClause = false;
1.80 +
1.81 + /** Create an outermost environment for a given (toplevel)tree,
1.82 + * with a given info field.
1.83 + */
1.84 + public Env(JCTree tree, A info) {
1.85 + this.next = null;
1.86 + this.outer = null;
1.87 + this.tree = tree;
1.88 + this.toplevel = null;
1.89 + this.enclClass = null;
1.90 + this.enclMethod = null;
1.91 + this.info = info;
1.92 + }
1.93 +
1.94 + /** Duplicate this environment, updating with given tree and info,
1.95 + * and copying all other fields.
1.96 + */
1.97 + public Env<A> dup(JCTree tree, A info) {
1.98 + return dupto(new Env<A>(tree, info));
1.99 + }
1.100 +
1.101 + /** Duplicate this environment into a given Environment,
1.102 + * using its tree and info, and copying all other fields.
1.103 + */
1.104 + public Env<A> dupto(Env<A> that) {
1.105 + that.next = this;
1.106 + that.outer = this.outer;
1.107 + that.toplevel = this.toplevel;
1.108 + that.enclClass = this.enclClass;
1.109 + that.enclMethod = this.enclMethod;
1.110 + return that;
1.111 + }
1.112 +
1.113 + /** Duplicate this environment, updating with given tree,
1.114 + * and copying all other fields.
1.115 + */
1.116 + public Env<A> dup(JCTree tree) {
1.117 + return dup(tree, this.info);
1.118 + }
1.119 +
1.120 + /** Return closest enclosing environment which points to a tree with given tag.
1.121 + */
1.122 + public Env<A> enclosing(JCTree.Tag tag) {
1.123 + Env<A> env1 = this;
1.124 + while (env1 != null && !env1.tree.hasTag(tag)) env1 = env1.next;
1.125 + return env1;
1.126 + }
1.127 +
1.128 + @Override
1.129 + public String toString() {
1.130 + StringBuilder sb = new StringBuilder();
1.131 + sb.append("Env[").append(info);
1.132 +// if (enclMethod != null)
1.133 +// sb.append(",enclMethod=").append(Pretty.toSimpleString(enclMethod));
1.134 +// if (enclClass != null)
1.135 +// sb.append(",enclClass=").append(Pretty.toSimpleString(enclClass));
1.136 + if (outer != null)
1.137 + sb.append(",outer=").append(outer);
1.138 + sb.append("]");
1.139 + return sb.toString();
1.140 + }
1.141 +
1.142 + public Iterator<Env<A>> iterator() {
1.143 + return new Iterator<Env<A>>() {
1.144 + Env<A> next = Env.this;
1.145 + public boolean hasNext() {
1.146 + return next.outer != null;
1.147 + }
1.148 + public Env<A> next() {
1.149 + if (hasNext()) {
1.150 + Env<A> current = next;
1.151 + next = current.outer;
1.152 + return current;
1.153 + }
1.154 + throw new NoSuchElementException();
1.155 +
1.156 + }
1.157 + public void remove() {
1.158 + throw new UnsupportedOperationException();
1.159 + }
1.160 + };
1.161 + }
1.162 +}
