001    /*
002     *  This file is part of the Jikes RVM project (http://jikesrvm.org).
003     *
004     *  This file is licensed to You under the Eclipse Public License (EPL);
005     *  You may not use this file except in compliance with the License. You
006     *  may obtain a copy of the License at
007     *
008     *      http://www.opensource.org/licenses/eclipse-1.0.php
009     *
010     *  See the COPYRIGHT.txt file distributed with this work for information
011     *  regarding copyright ownership.
012     */
013    package org.vmmagic.pragma;
014    
015    import java.lang.annotation.Retention;
016    import java.lang.annotation.Target;
017    import java.lang.annotation.RetentionPolicy;
018    import java.lang.annotation.ElementType;
019    import org.vmmagic.Pragma;
020    
021    /**
022     * This pragma is used to indicate a method has no side effects. Use this pragma
023     * with care as it can cause compile time invocation of the method it is placed
024     * on. This pragma is used to imply weak purity of a method, and as such cannot
025     * remove calls to pure methods - as they may throw exceptions.
026     * {@link <a href="http://jira.codehaus.org/browse/RVM-503">RVM-503</a>}.
027     */
028    @Retention(RetentionPolicy.RUNTIME)
029    @Target({ElementType.METHOD})
030    @Pragma
031    public @interface Pure { /* annotation has no value */ }