001/*
002 * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.compiler.match;
024
025import java.lang.annotation.*;
026
027import com.oracle.graal.nodes.*;
028
029/**
030 * This annotation declares a textual pattern for matching an HIR tree. The format is a LISP style
031 * s-expression with node types and/or names that are matched against the HIR. Node types are always
032 * uppercase and the names of nodes are always lowercase. Named nodes can be used to match trees
033 * where a node is used multiple times but only as an input to the full match.
034 *
035 * <pre>
036 *   &lt;node-name&gt;    := [a-z][a-zA-Z0-9]*
037 *   &lt;node-type&gt;    := [A-Z][a-zA-Z0-9]*
038 *   &lt;node-spec&gt;    := &lt;node-type&gt; { '=' &lt;node-name&gt; }
039 *   &lt;node-or-name&gt; := &lt;node-spec&gt; | &lt;node-name&gt;
040 *   &lt;argument&gt;     := &lt;node-or-name&gt; | &lt;match-rule&gt;
041 *   &lt;match-rule&gt;   := '(' &lt;node-spec&gt; &lt;argument&gt;+ ')'
042 * </pre>
043 *
044 * All matched nodes except the root of the match and {@link ConstantNode}s must have a single user.
045 * All matched nodes must be in the same block.
046 */
047
048@Retention(RetentionPolicy.RUNTIME)
049@Target(ElementType.METHOD)
050@Repeatable(value = MatchRules.class)
051public @interface MatchRule {
052    String value();
053}