// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System.Diagnostics.CodeAnalysis;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Security;
using System.Threading;
 
namespace System.Reflection
{
    public abstract partial class MethodBase : MemberInfo
    {
        #region Static Members
        public static MethodBase? GetMethodFromHandle(RuntimeMethodHandle handle)
        {
            if (handle.IsNullHandle())
                throw new ArgumentException(SR.Argument_InvalidHandle);
 
            MethodBase? m = RuntimeType.GetMethodBase(handle.GetMethodInfo());
 
            Type? declaringType = m?.DeclaringType;
            if (declaringType != null && declaringType.IsGenericType)
                throw new ArgumentException(SR.Format(
                    SR.Argument_MethodDeclaringTypeGeneric,
                    m, declaringType.GetGenericTypeDefinition()));
 
            return m;
        }
 
        public static MethodBase? GetMethodFromHandle(RuntimeMethodHandle handle, RuntimeTypeHandle declaringType)
        {
            if (handle.IsNullHandle())
                throw new ArgumentException(SR.Argument_InvalidHandle);
 
            return RuntimeType.GetMethodBase(declaringType.GetRuntimeType(), handle.GetMethodInfo());
        }
 
        [LibraryImport(RuntimeHelpers.QCall, EntryPoint = "MethodBase_GetCurrentMethod")]
        private static partial RuntimeMethodHandleInternal GetCurrentMethod(StackCrawlMarkHandle stackMark);
 
        [RequiresUnreferencedCode("Metadata for the method might be incomplete or removed")]
        [DynamicSecurityMethod] // Methods containing StackCrawlMark local var has to be marked DynamicSecurityMethod
        public static MethodBase? GetCurrentMethod()
        {
            StackCrawlMark stackMark = StackCrawlMark.LookForMyCaller;
            RuntimeMethodHandleInternal methodHandle = GetCurrentMethod(new StackCrawlMarkHandle(ref stackMark));
            return methodHandle.IsNullHandle() ? null : RuntimeType.GetMethodBase(null, methodHandle);
        }
        #endregion
 
        #region Internal Members
        // used by EE
        private IntPtr GetMethodDesc() { return MethodHandle.Value; }
 
        internal virtual ReadOnlySpan<ParameterInfo> GetParametersAsSpan() { return GetParameters(); }
        #endregion
    }
}