/*

 * Copyright (c) 2009, 2015, 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 jdk.vm.ci.meta;

/**

 * Represents a method signature provided by the runtime.

 *

 * @see <a href="http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.3.3">Method

 *      Descriptors</a>

 */

public interface Signature {

    /**

     * Returns the number of parameters in this signature, adding 1 for a receiver if requested.

     *

     * @param receiver true if 1 is to be added to the result for a receiver

     * @return the number of parameters; + 1 iff {@code receiver == true}

     */

    int getParameterCount(boolean receiver);

    /**

     * Gets the parameter type at the specified position.

     *

     * @param index the index into the parameters, with {@code 0} indicating the first parameter

     * @param accessingClass the context of the type lookup. If non-null, its class loader is used

     *            for resolving the type. If {@code null}, then the type returned is either

     *            unresolved or a resolved type whose resolution is context free (e.g., a primitive

     *            type or a type in a java.* package).

     * @return the {@code index}'th parameter type

     * @throws LinkageError if {@code accessingClass != null} and resolution fails

     *

     */

    JavaType getParameterType(int index, ResolvedJavaType accessingClass);

    /**

     * Gets the parameter kind at the specified position. This is the same as calling

     * {@link #getParameterType}. {@link JavaType#getJavaKind getJavaKind}.

     *

     * @param index the index into the parameters, with {@code 0} indicating the first parameter

     * @return the kind of the parameter at the specified position

     */

    default JavaKind getParameterKind(int index) {

        return getParameterType(index, null).getJavaKind();

    }

    /**

     * Gets the return type of this signature.

     *

     * @param accessingClass the context of the type lookup. If non-null, its class loader is used

     *            for resolving the type. If {@code null}, then the type returned is either

     *            unresolved or a resolved type whose resolution is context free (e.g., a primitive

     *            type or a type in a java.* package).

     * @return the return type

     * @throws LinkageError if {@code accessingClass != null} and resolution fails

     */

    JavaType getReturnType(ResolvedJavaType accessingClass);

    /**

     * Gets the return kind of this signature. This is the same as calling {@link #getReturnType}.

     * {@link JavaType#getJavaKind getJavaKind}.

     */

    default JavaKind getReturnKind() {

        return getReturnType(null).getJavaKind();

    }

    /**

     * Gets the

     * <a href="http://docs.oracle.com/javase/specs/jvms/se7/html/jvms-4.html#jvms-4.3.3">method

     * descriptor</a> corresponding to this signature. For example:

     *

     * <pre>

     * (ILjava/lang/String;D)V

     * </pre>

     *

     * @return the signature as a string

     */

    default String toMethodDescriptor() {

        StringBuilder sb = new StringBuilder("(");

        for (int i = 0; i < getParameterCount(false); ++i) {

            sb.append(getParameterType(i, null).getName());

        }

        sb.append(')').append(getReturnType(null).getName());

        return sb.toString();

    }

    default JavaType[] toParameterTypes(JavaType receiverType) {

        int args = getParameterCount(false);

        JavaType[] result;

        int i = 0;

        if (receiverType != null) {

            result = new JavaType[args + 1];

            result[0] = receiverType;

            i = 1;

        } else {

            result = new JavaType[args];

        }

        for (int j = 0; j < args; j++) {

            result[i + j] = getParameterType(j, null);

        }

        return result;

    }

    default JavaKind[] toParameterKinds(boolean receiver) {

        int args = getParameterCount(false);

        JavaKind[] result;

        int i = 0;

        if (receiver) {

            result = new JavaKind[args + 1];

            result[0] = JavaKind.Object;

            i = 1;

        } else {

            result = new JavaKind[args];

        }

        for (int j = 0; j < args; j++) {

            result[i + j] = getParameterKind(j);

        }

        return result;

    }

}