Convert some more array FCalls to managed

src/coreclr/System.Private.CoreLib/src/System/Runtime/CompilerServices/CastHelpers.cs

@@ -29,7 +29,7 @@ internal static unsafe class CastHelpers
         // Unlike the IsInstanceOfInterface and IsInstanceOfClass functions,
         // this test must deal with all kinds of type tests
         [DebuggerHidden]
-        private static object? IsInstanceOfAny(void* toTypeHnd, object? obj)
+        internal static object? IsInstanceOfAny(void* toTypeHnd, object? obj)
         {
             if (obj != null)
             {

src/coreclr/System.Private.CoreLib/src/System/Runtime/CompilerServices/RuntimeHelpers.CoreCLR.cs

@@ -1,28 +1,115 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Buffers.Binary;
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
-using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Runtime.Serialization;
 using System.Runtime.Versioning;
-using System.Threading;
 
 namespace System.Runtime.CompilerServices
 {
     public static partial class RuntimeHelpers
     {
         [Intrinsic]
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        public static extern void InitializeArray(Array array, RuntimeFieldHandle fldHandle);
+        public static unsafe void InitializeArray(Array array, RuntimeFieldHandle fldHandle)
+        {
+            RtFieldInfo fldInfo = (RtFieldInfo)FieldInfo.GetFieldFromHandle(fldHandle);
 
-        [MethodImpl(MethodImplOptions.InternalCall)]
-        private static extern unsafe void* GetSpanDataFrom(
+            if (array is null)
+                ThrowHelper.ThrowArgumentNullException(ExceptionArgument.array);
+
+            if ((fldInfo.Attributes & FieldAttributes.HasFieldRVA) == 0)
+                ThrowHelper.ThrowArgumentException(ExceptionResource.Argument_BadFieldForInitializeArray);
+
+            // Note that we do not check that the field is actually in the PE file that is initializing
+            // the array. Basically the data being published is can be accessed by anyone with the proper
+            // permissions (C# marks these as assembly visibility, and thus are protected from outside
+            // snooping)
+
+            if (!array.GetCorElementTypeOfElementType().IsPrimitiveType()) // Enum is included
+                ThrowHelper.ThrowArgumentException(ExceptionResource.Argument_MustBePrimitiveArray);
+
+            MethodTable* pMT = GetMethodTable(array);
+            nuint totalSize = pMT->ComponentSize * array.NativeLength;
+
+            uint size = ((MethodTable*)((RuntimeType)fldInfo.FieldType).TypeHandle.Value)->GetNumInstanceFieldBytes();
+
+            // make certain you don't go off the end of the rva static
+            if (totalSize > size)
+                ThrowHelper.ThrowArgumentException(ExceptionResource.Argument_BadFieldForInitializeArray);
+
+            void* src = (void*)RuntimeFieldHandle.GetStaticFieldAddress(fldInfo);
+            ref byte dst = ref MemoryMarshal.GetArrayDataReference(array);
+
+            Debug.Assert(!pMT->GetArrayElementTypeHandle().AsMethodTable()->ContainsGCPointers);
+
+            if (BitConverter.IsLittleEndian)
+            {
+                SpanHelpers.Memmove(ref dst, ref *(byte*)src, totalSize);
+            }
+            else
+            {
+                switch (pMT->ComponentSize)
+                {
+                    case 1:
+                        SpanHelpers.Memmove(ref dst, ref *(byte*)src, totalSize);
+                        break;
+                    case 2:
+                        BinaryPrimitives.ReverseEndianness(
+                            new ReadOnlySpan<ushort>(src, array.Length),
+                            new Span<ushort>(ref Unsafe.As<byte, ushort>(ref dst), array.Length));
+                        break;
+                    case 4:
+                        BinaryPrimitives.ReverseEndianness(
+                            new ReadOnlySpan<uint>(src, array.Length),
+                            new Span<uint>(ref Unsafe.As<byte, uint>(ref dst), array.Length));
+                        break;
+                    case 8:
+                        BinaryPrimitives.ReverseEndianness(
+                            new ReadOnlySpan<ulong>(src, array.Length),
+                            new Span<ulong>(ref Unsafe.As<byte, ulong>(ref dst), array.Length));
+                        break;
+                    default:
+                        Debug.Fail("Incorrect primitive type size!");
+                        break;
+                }
+            }
+        }
+
+        private static unsafe void* GetSpanDataFrom(
             RuntimeFieldHandle fldHandle,
             RuntimeTypeHandle targetTypeHandle,
-            out int count);
+            out int count)
+        {
+            RtFieldInfo fldInfo = (RtFieldInfo)FieldInfo.GetFieldFromHandle(fldHandle);
+
+            if ((fldInfo.Attributes & FieldAttributes.HasFieldRVA) == 0)
+                ThrowHelper.ThrowArgumentException(ExceptionResource.Argument_BadFieldForInitializeArray);
+
+            TypeHandle th = new TypeHandle((void*)targetTypeHandle.Value);
+            Debug.Assert(!th.IsTypeDesc); // TypeDesc can't be used as generic parameter
+
+            if (!th.GetVerifierCorElementType().IsPrimitiveType()) // Enum is included
+                ThrowHelper.ThrowArgumentException(ExceptionResource.Argument_MustBePrimitiveArray);
+
+            uint totalSize = ((MethodTable*)((RuntimeType)fldInfo.FieldType).TypeHandle.Value)->GetNumInstanceFieldBytes();
+            uint targetTypeSize = th.AsMethodTable()->GetNumInstanceFieldBytes();
+
+            IntPtr data = RuntimeFieldHandle.GetStaticFieldAddress(fldInfo);
+            if (data % targetTypeSize != 0)
+                ThrowHelper.ThrowArgumentException(ExceptionResource.Argument_BadFieldForInitializeArray);
+
+            if (!BitConverter.IsLittleEndian)
+            {
+                throw new PlatformNotSupportedException();
+            }
+
+            count = (int)(totalSize / targetTypeSize);
+            return (void*)data;
+        }
 
         // GetObjectValue is intended to allow value classes to be manipulated as 'Object'
         // but have aliasing behavior of a value class.  The intent is that you would use
@@ -686,6 +773,8 @@ public int MultiDimensionalArrayRank
         // Warning! UNLIKE the similarly named Reflection api, this method also returns "true" for Enums.
         public bool IsPrimitive => (Flags & enum_flag_Category_Mask) is enum_flag_Category_PrimitiveValueType or enum_flag_Category_TruePrimitive;
 
+        public bool IsTruePrimitive => (Flags & enum_flag_Category_Mask) is enum_flag_Category_TruePrimitive;
+
         public bool HasInstantiation => (Flags & enum_flag_HasComponentSize) == 0 && (Flags & enum_flag_GenericsMask) != enum_flag_GenericsMask_NonGeneric;
 
         public bool IsGenericTypeDefinition => (Flags & (enum_flag_HasComponentSize | enum_flag_GenericsMask)) == enum_flag_GenericsMask_TypicalInst;
@@ -715,6 +804,13 @@ public TypeHandle GetArrayElementTypeHandle()
 
         [MethodImpl(MethodImplOptions.InternalCall)]
         public extern uint GetNumInstanceFieldBytes();
+
+        [MethodImpl(MethodImplOptions.InternalCall)]
+        public extern CorElementType GetVerifierCorElementType();
+
+        [MethodImpl(MethodImplOptions.InternalCall)]
+        internal static extern bool CanCastTo_NoCacheLookup(void* fromTypeHnd, void* toTypeHnd);
+
     }
 
     // Subset of src\vm\methodtable.h
@@ -740,9 +836,9 @@ public bool CanCompareBitsOrUseFastGetHashCode
     }
 
     /// <summary>
-    /// A type handle, which can wrap either a pointer to a <c>TypeDesc</c> or to a <see cref="MethodTable"/>.
+    /// A type handle, which can wrap either a pointer to a <see cref="TypeDesc"/> or to a <see cref="MethodTable"/>.
     /// </summary>
-    internal unsafe struct TypeHandle
+    internal readonly unsafe struct TypeHandle
     {
         // Subset of src\vm\typehandle.h
 
@@ -784,11 +880,63 @@ public bool IsTypeDesc
             return (MethodTable*)m_asTAddr;
         }
 
+        /// <summary>
+        /// Gets the <see cref="TypeDesc"/> pointer wrapped by the current instance.
+        /// </summary>
+        /// <remarks>This is only safe to call if <see cref="IsTypeDesc"/> returned <see langword="true"/>.</remarks>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public TypeDesc* AsTypeDesc()
+        {
+            Debug.Assert(IsTypeDesc);
+
+            return (TypeDesc*)((nint)m_asTAddr - 2);
+        }
+
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static TypeHandle TypeHandleOf<T>()
         {
             return new TypeHandle((void*)RuntimeTypeHandle.ToIntPtr(typeof(T).TypeHandle));
         }
+
+        public static bool AreSameType(TypeHandle left, TypeHandle right) => left.m_asTAddr == right.m_asTAddr;
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public bool CanCastTo(TypeHandle destTH)
+        {
+            CastResult result = CastCache.TryGet(CastHelpers.s_table!, (nuint)m_asTAddr, (nuint)destTH.m_asTAddr);
+
+            if (result != CastResult.MaybeCast)
+                return result == CastResult.CanCast;
+
+            return MethodTable.CanCastTo_NoCacheLookup(m_asTAddr, destTH.m_asTAddr);
+        }
+
+        public bool IsValueType
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get
+            {
+                return IsTypeDesc
+                    ? AsTypeDesc()->GetInternalCorElementType() == CorElementType.ELEMENT_TYPE_VALUETYPE
+                    : AsMethodTable()->IsValueType;
+            }
+        }
+
+        public bool IsInterface => !IsTypeDesc && AsMethodTable()->IsInterface;
+
+        public CorElementType GetVerifierCorElementType() => IsTypeDesc
+            ? AsTypeDesc()->GetInternalCorElementType()
+            : AsMethodTable()->GetVerifierCorElementType();
+    }
+
+    internal unsafe struct TypeDesc
+    {
+        private readonly int m_typeAndFlags;
+
+        // This is the ELEMENT_TYPE* that would be used in the type sig for this type
+        // For enums this is the underlying type
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public CorElementType GetInternalCorElementType() => (CorElementType)(m_typeAndFlags & 0xFF);
     }
 
     // Helper structs used for tail calls via helper.