/*
 * Copyright (c) 2011, 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 com.oracle.graal.snippets;

import java.lang.annotation.*;

import com.oracle.graal.api.meta.*;
import com.oracle.graal.nodes.*;
import com.oracle.graal.snippets.nodes.*;

/**
 * Denotes a class that substitutes methods of another specified class. The substitute methods are
 * exactly those annotated by {@link MethodSubstitution}.
 */
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
public @interface ClassSubstitution {

    /**
     * Specifies the original class.
     * <p>
     * If the default value is specified for this element, then a non-default value must be given
     * for the {@link #className()} element.
     */
    Class<?> value() default ClassSubstitution.class;

    /**
     * Specifies the original class.
     * <p>
     * This method is provided for cases where the original class is not accessible (according to
     * Java language access control rules).
     * <p>
     * If the default value is specified for this element, then a non-default value must be given
     * for the {@link #value()} element.
     */
    String className() default "";

    /**
     * Denotes a substitute method. A substitute method can call the original/substituted method by
     * making a recursive call to itself.
     */
    @Retention(RetentionPolicy.RUNTIME)
    @Target(ElementType.METHOD)
    public @interface MethodSubstitution {

        /**
         * Gets the name of the original method.
         * <p>
         * If the default value is specified for this element, then the name of the original method
         * is same as the substitute method.
         */
        String value() default "";

        /**
         * Determines if the original method is static.
         */
        boolean isStatic() default true;

        /**
         * Gets the {@linkplain Signature#getMethodDescriptor() signature} of the original method.
         * <p>
         * If the default value is specified for this element, then the signature of the original
         * method is the same as the substitute method.
         */
        String signature() default "";
    }

    /**
     * Denotes a macro substitute method. This replaces a method invocation with an instance of the
     * specified node class.
     * 
     * A macro substitution can be combined with a normal substitution, so that the macro node can
     * be replaced with the actual substitution code during lowering.
     */
    @Retention(RetentionPolicy.RUNTIME)
    @Target(ElementType.METHOD)
    public @interface MacroSubstitution {

        /**
         * Gets the name of the substituted method.
         * <p>
         * If the default value is specified for this element, then the name of the substituted
         * method is same as the substitute method.
         */
        String value() default "";

        /**
         * Determines if the substituted method is static.
         */
        boolean isStatic() default true;

        /**
         * Gets the {@linkplain Signature#getMethodDescriptor() signature} of the substituted
         * method.
         * <p>
         * If the default value is specified for this element, then the signature of the substituted
         * method is the same as the substitute method.
         */
        String signature() default "";

        /**
         * The node class with which the method invocation should be replaced. It needs to be a
         * subclass of {@link FixedWithNextNode}, and it is expected to provide a public constructor
         * that takes an InvokeNode as a parameter. For most cases this class should subclass
         * {@link MacroNode} and use its constructor.
         */
        Class<? extends FixedWithNextNode> macro();
    }
}