/*
 * Copyright (c) 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
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 */
package compiler.jvmci.CompilerToVM;

import jdk.internal.jvmci.hotspot.*;
import jdk.internal.jvmci.hotspot.CompilerToVMHelper;

import java.lang.reflect.Constructor;
import java.lang.reflect.Executable;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Objects;

public class ResolvedMethodGetter {

    public static HotSpotResolvedJavaMethodImpl getResolvedMethod(
            Class<?> aClass, String methodName, Class<?>... types) {
        Objects.requireNonNull(methodName, "methodName cannot be null");
        if ("<cinit>".equals(methodName)) {
            if (types != null && types.length != 0) {
                throw new IllegalArgumentException(
                        "<cinit> cannot have arguments");
            }
            HotSpotResolvedObjectTypeImpl objectType
                    = HotSpotResolvedObjectTypeImpl.fromObjectClass(aClass);
            return CompilerToVMHelper.getClassInitializer(objectType);
        } else {
            Executable method;
            try {
                if ("<init>".equals(methodName)) {
                    method = aClass.getDeclaredConstructor(types);
                } else {
                    method = aClass.getDeclaredMethod(methodName, types);
                }
            } catch (NoSuchMethodException e) {
                throw new Error("TEST BUG: unable to get method", e);
            }
            return getResolvedMethod(method);
        }
    }

    public static HotSpotResolvedJavaMethodImpl getResolvedMethod(
            Executable executable) {
        if (!(executable instanceof Method)
                && !(executable instanceof Constructor)) {
            throw new Error("TEST BUG: wrong executable type");
        }
        try {
            Field slotField = executable.getClass().getDeclaredField("slot");
            slotField.setAccessible(true);
            int slotNum = (int) slotField.get(executable);
            return CompilerToVMHelper.getResolvedJavaMethodAtSlot(
                    executable.getDeclaringClass(), slotNum);
        } catch (ReflectiveOperationException e) {
            throw new Error("TEST BUG: unable to get slot of the given method");
        }
    }
}