/*

 * Copyright (c) 2020, 2021, 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 jdk.internal.invoke;

import java.lang.invoke.MethodType;

import java.util.Objects;

/**

 * This class describes a native call, including arguments/return shuffle moves, PC entry point and

 * various other info which are relevant when the call will be intrinsified by C2.

 */

public class NativeEntryPoint {

    static {

        registerNatives();

    }

    private final int shadowSpace;

    // encoded as VMRegImpl*

    private final long[] argMoves;

    private final long[] returnMoves;

    private final boolean needTransition;

    private final MethodType methodType; // C2 sees erased version (byte -> int), so need this explicitly

    private final String name;

    private NativeEntryPoint(int shadowSpace, long[] argMoves, long[] returnMoves,

                     boolean needTransition, MethodType methodType, String name) {

        this.shadowSpace = shadowSpace;

        this.argMoves = Objects.requireNonNull(argMoves);

        this.returnMoves = Objects.requireNonNull(returnMoves);

        this.needTransition = needTransition;

        this.methodType = methodType;

        this.name = name;

    }

    public static NativeEntryPoint make(String name, ABIDescriptorProxy abi,

                                        VMStorageProxy[] argMoves, VMStorageProxy[] returnMoves,

                                        boolean needTransition, MethodType methodType) {

        if (returnMoves.length > 1) {

            throw new IllegalArgumentException("Multiple register return not supported");

        }

        return new NativeEntryPoint(abi.shadowSpaceBytes(), encodeVMStorages(argMoves), encodeVMStorages(returnMoves),

                needTransition, methodType, name);

    }

    private static long[] encodeVMStorages(VMStorageProxy[] moves) {

        long[] out = new long[moves.length];

        for (int i = 0; i < moves.length; i++) {

            out[i] = vmStorageToVMReg(moves[i].type(), moves[i].index());

        }

        return out;

    }

    private static native long vmStorageToVMReg(int type, int index);

    public MethodType type() {

        return methodType;

    }

    private static native void registerNatives();

}