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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<!--
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Copyright 2006 Sun Microsystems, Inc. All Rights Reserved.
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DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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This code is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License version 2 only, as
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published by the Free Software Foundation. Sun designates this
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particular file as subject to the "Classpath" exception as provided
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by Sun in the LICENSE file that accompanied this code.
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This code is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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version 2 for more details (a copy is included in the LICENSE file that
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accompanied this code).
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You should have received a copy of the GNU General Public License version
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2 along with this work; if not, write to the Free Software Foundation,
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Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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CA 95054 USA or visit www.sun.com if you need additional information or
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have any questions.
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-->
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<html>
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<head>
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<meta http-equiv="content-type" content="text/html; charset=ISO-8859-1">
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<meta name="author" content="Jonathan Gibbons">
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<link type="text/css" rel=stylesheet href="style.css">
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<title>com.sun.tools.javac.comp.Enter</title>
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</head>
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<body>
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<h3>com.sun.tools.javac.comp.Enter</h3>
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This enters symbols for all encountered definitions into
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the symbol table. The pass consists of two phases, organized as
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follows:
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<ol>
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<li><p>In the first phase, all class symbols are entered into their
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enclosing scope, descending recursively down the tree for classes
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which are members of other classes. The class symbols are given a
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MemberEnter object as completer.</p></li>
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<p><a name="package-info"></a>In addition,
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if any <span class=code>package-info.java</span> files are found,
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containing package annotations, then the TopLevel tree node for
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the package-info.java file is put on the "to do" as well.
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</p>
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<li><p>In the second phase, classes are completed using
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MemberEnter.complete(). Completion might occur on demand, but
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any classes that are not completed that way will be eventually
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completed by processing the `uncompleted' queue. Completion
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entails
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<ul><li>(1) determination of a class's parameters, supertype and
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interfaces, as well as <li>(2) entering all symbols defined in the
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class into its scope, with the exception of class symbols which
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have been entered in phase 1.</li>
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</ul>
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(2) depends on (1) having been
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completed for a class and all its superclasses and enclosing
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classes. That's why, after doing (1), we put classes in a
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`halfcompleted' queue. Only when we have performed (1) for a class
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and all it's superclasses and enclosing classes, we proceed to
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(2).</p></li>
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</ol>
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<p>Whereas the first phase is organized as a sweep through all
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compiled syntax trees, the second phase is demand. Members of a
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class are entered when the contents of a class are first
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accessed. This is accomplished by installing completer objects in
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class symbols for compiled classes which invoke the member-enter
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phase for the corresponding class tree.</p>
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<p>Classes migrate from one phase to the next via queues:</p>
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<pre>
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class enter -> (Enter.uncompleted) --> member enter (1)
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-> (MemberEnter.halfcompleted) --> member enter (2)
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-> (Todo) --> attribute
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(only for toplevel classes)
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</pre>
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</body>
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</html>
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