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 */
013package org.vmmagic;
014
015import java.lang.annotation.Retention;
016import java.lang.annotation.RetentionPolicy;
017import java.lang.annotation.Target;
018import java.lang.annotation.ElementType;
019import java.lang.annotation.Inherited;
020
021/**
022 * A Pragma is a mechanism for supplying information to the compiler to alter the code it
023 * generates for a method. A Pragma is similar to an {@link org.vmmagic.Intrinsic}
024 * but it does not provide any behaviour but provides information to the compiler that modifies
025 * optimizations, calling conventions and activation frame layout.
026 *
027 * <p>If the Pragma annotation is applied to a method then then the method is a handled specially
028 * by the compiler. If the Pragma annotation is applied to a class then then all the methods in that
029 * class are handled specially by the compiler.</p>
030 *
031 * <p>NOTE: At the current time the Pragma annotation is only used for documentation
032 * purposes but in the near future it is expected that the semantics of the annotation will
033 * be enforced by the compiler.</p>
034 */
035@Retention(RetentionPolicy.RUNTIME)
036@Target({ElementType.TYPE,ElementType.ANNOTATION_TYPE})
037@Inherited
038public @interface Pragma { }