/*
* Copyright (c) 2014, 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.
*
* 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 org.graalvm.compiler.core.match;
import java.lang.annotation.ElementType;
import java.lang.annotation.Repeatable;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import org.graalvm.compiler.nodes.ConstantNode;
/**
* This annotation declares a textual pattern for matching an HIR tree. The format is a LISP style
* s-expression with node types and/or names that are matched against the HIR. Node types are always
* uppercase and the names of nodes are always lowercase. Named nodes can be used to match trees
* where a node is used multiple times but only as an input to the full match.
*
* <pre>
* <node-name> := [a-z][a-zA-Z0-9]*
* <node-type> := [A-Z][a-zA-Z0-9]*
* <node-spec> := <node-type> { '=' <node-name> }
* <node-or-name> := <node-spec> | <node-name>
* <argument> := <node-or-name> | <match-rule>
* <match-rule> := '(' <node-spec> <argument>+ ')'
* </pre>
*
* All matched nodes except the root of the match and {@link ConstantNode}s must have a single user.
* All matched nodes must be in the same block.
*/
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
@Repeatable(value = MatchRules.class)
public @interface MatchRule {
String value();
}