/*

 * Copyright (c) 2010, 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.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * 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

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 */

package java.dyn;

import java.lang.annotation.*;

/**

 * Annotation on InvokeDynamic method calls which requests the JVM to use a specific

 * <a href="package-summary.html#bsm">bootstrap method</a>

 * to link the call.  This annotation is not retained as such in the class file,

 * but is transformed into a constant-pool entry for the invokedynamic instruction which

 * specifies the desired bootstrap method.

 * <p>

 * If only the <code>value</code> is given, it must name a subclass of {@link CallSite}

 * with a constructor which accepts a class, string, and method type.

 * If the <code>value</code> and <code>name</code> are both given, there must be

 * a static method in the given class of the given name which accepts a class, string,

 * and method type, and returns a reference coercible to {@link CallSite}.

 * <p>

 * This annotation can be placed either on the return type of a single {@link InvokeDynamic}

 * call (see examples) or else it can be placed on an enclosing class or method, where it

 * determines a default bootstrap method for any {@link InvokeDynamic} calls which are not

 * specifically annotated with a bootstrap method.

 * Every {@link InvokeDynamic} call must be given a bootstrap method.

 * <p>

 * Examples:

<blockquote><pre>

@BootstrapMethod(value=MyLanguageRuntime.class, name="bootstrapDynamic")

String x = (String) InvokeDynamic.greet();

//BSM => MyLanguageRuntime.bootstrapDynamic(Here.class, "greet", methodType(String.class))

@BootstrapMethod(MyCallSite.class)

void example() throws Throwable {

    InvokeDynamic.greet();

    //BSM => new MyCallSite(Here.class, "greet", methodType(void.class))

}

</pre></blockquote>

 * <p>

 */

@Target({ElementType.TYPE_USE,

            // For defaulting every indy site within a class or method; cf. @SuppressWarnings:

            ElementType.TYPE, ElementType.METHOD, ElementType.CONSTRUCTOR

            })

@Retention(RetentionPolicy.SOURCE)

public @interface BootstrapMethod {

    /** The class containing the bootstrap method. */

    Class<?> value();

    /** The name of the bootstrap method.

     *  If this is the empty string, an instance of the bootstrap class is created,

     *  and a constructor is invoked.

     *  Otherwise, there must be a static method of the required name.

     */

    String name() default "";  // empty string denotes a constructor with 'new'

    /** The argument types of the bootstrap method, as passed out by the JVM.

     *  There is usually no reason to override the default.

     */

    Class<?>[] arguments() default {Class.class, String.class, MethodType.class};

}