Mercurial > jdk8-mips64-public > langtools / file revision

 /*

  * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  */

 package com.sun.tools.javac.comp;

 import com.sun.tools.javac.tree.*;

 import java.util.Iterator;

 import java.util.NoSuchElementException;

 /** A class for environments, instances of which are passed as

  *  arguments to tree visitors.  Environments refer to important ancestors

  *  of the subtree that's currently visited, such as the enclosing method,

  *  the enclosing class, or the enclosing toplevel node. They also contain

  *  a generic component, represented as a type parameter, to carry further

  *  information specific to individual passes.

  *

  *  <p><b>This is NOT part of any supported API.

  *  If you write code that depends on this, you do so at your own risk.

  *  This code and its internal interfaces are subject to change or

  *  deletion without notice.</b>

  */

 public class Env<A> implements Iterable<Env<A>> {

     /** The next enclosing environment.

      */

     public Env<A> next;

     /** The environment enclosing the current class.

      */

     public Env<A> outer;

     /** The tree with which this environment is associated.

      */

     public JCTree tree;

     /** The enclosing toplevel tree.

      */

     public JCTree.JCCompilationUnit toplevel;

     /** The next enclosing class definition.

      */

     public JCTree.JCClassDecl enclClass;

     /** The next enclosing method definition.

      */

     public JCTree.JCMethodDecl enclMethod;

     /** A generic field for further information.

      */

     public A info;

     /** Is this an environment for evaluating a base clause?

      */

     public boolean baseClause = false;

     /** Create an outermost environment for a given (toplevel)tree,

      *  with a given info field.

      */

     public Env(JCTree tree, A info) {

         this.next = null;

         this.outer = null;

         this.tree = tree;

         this.toplevel = null;

         this.enclClass = null;

         this.enclMethod = null;

         this.info = info;

     }

     /** Duplicate this environment, updating with given tree and info,

      *  and copying all other fields.

      */

     public Env<A> dup(JCTree tree, A info) {

         return dupto(new Env<A>(tree, info));

     }

     /** Duplicate this environment into a given Environment,

      *  using its tree and info, and copying all other fields.

      */

     public Env<A> dupto(Env<A> that) {

         that.next = this;

         that.outer = this.outer;

         that.toplevel = this.toplevel;

         that.enclClass = this.enclClass;

         that.enclMethod = this.enclMethod;

         return that;

     }

     /** Duplicate this environment, updating with given tree,

      *  and copying all other fields.

      */

     public Env<A> dup(JCTree tree) {

         return dup(tree, this.info);

     }

     /** Return closest enclosing environment which points to a tree with given tag.

      */

     public Env<A> enclosing(JCTree.Tag tag) {

         Env<A> env1 = this;

         while (env1 != null && !env1.tree.hasTag(tag)) env1 = env1.next;

         return env1;

     }

     @Override

     public String toString() {

         StringBuilder sb = new StringBuilder();

         sb.append("Env[").append(info);

 //        if (enclMethod != null)

 //            sb.append(",enclMethod=").append(Pretty.toSimpleString(enclMethod));

 //        if (enclClass != null)

 //            sb.append(",enclClass=").append(Pretty.toSimpleString(enclClass));

         if (outer != null)

             sb.append(",outer=").append(outer);

         sb.append("]");

         return sb.toString();

     }

     public Iterator<Env<A>> iterator() {

         return new Iterator<Env<A>>() {

             Env<A> next = Env.this;

             public boolean hasNext() {

                 return next.outer != null;

             }

             public Env<A> next() {

                 if (hasNext()) {

                     Env<A> current = next;

                     next = current.outer;

                     return current;

                 }

                 throw new NoSuchElementException();

             }

             public void remove() {

                 throw new UnsupportedOperationException();

             }

         };

     }

 }