1 files changed, 105 insertions, 0 deletions
diff --git a/src/System.Private.Interpreter/src/Internal/Runtime/Interpreter/StackItem.cs b/src/System.Private.Interpreter/src/Internal/Runtime/Interpreter/StackItem.cs
new file mode 100644
index 000000000..97578b61d
--- /dev/null
+++ b/src/System.Private.Interpreter/src/Internal/Runtime/Interpreter/StackItem.cs
@@ -0,0 +1,105 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+using Internal.IL;
+using Internal.TypeSystem;
+
+namespace Internal.Runtime.Interpreter
+{
+    [StructLayout(LayoutKind.Explicit)]
+    internal unsafe struct StackItem
+    {
+        [FieldOffset(0)]
+        private StackValueKind _kind;
+
+        [FieldOffset(8)]
+        private int _int32;
+
+        [FieldOffset(8)]
+        private long _int64;
+
+        [FieldOffset(8)]
+        private IntPtr _nativeInt;
+
+        [FieldOffset(8)]
+        private double _double;
+
+        [FieldOffset(16)]
+        private ValueType _valueType;
+
+        [FieldOffset(16)]
+        private object _objref;
+
+        public StackValueKind Kind => _kind;
+
+        public static StackItem FromInt32(int int32)
+        {
+            return new StackItem { _int32 = int32, _kind = StackValueKind.Int32 };
+        }
+
+        public int AsInt32()
+        {
+            Debug.Assert(_kind == StackValueKind.Int32);
+            return _int32;
+        }
+
+        public static StackItem FromInt64(long int64)
+        {
+            return new StackItem { _int64 = int64, _kind = StackValueKind.Int64 };
+        }
+
+        public long AsInt64()
+        {
+            Debug.Assert(_kind == StackValueKind.Int64);
+            return _int64;
+        }
+
+        public static StackItem FromIntPtr(IntPtr nativeInt)
+        {
+            return new StackItem { _nativeInt = nativeInt, _kind = StackValueKind.NativeInt };
+        }
+
+        public IntPtr AsIntPtr()
+        {
+            Debug.Assert(_kind == StackValueKind.NativeInt);
+            return _nativeInt;
+        }
+
+        public static StackItem FromDouble(double d)
+        {
+            return new StackItem { _double = d, _kind = StackValueKind.Float };
+        }
+
+        public double AsDouble()
+        {
+            Debug.Assert(_kind == StackValueKind.Float);
+            return _double;
+        }
+
+        public static StackItem FromValueType(ValueType valueType)
+        {
+            return new StackItem { _valueType = valueType, _kind = StackValueKind.ValueType };
+        }
+
+        public ValueType AsValueType()
+        {
+            Debug.Assert(_kind == StackValueKind.ValueType);
+            return _valueType;
+        }
+
+        public static StackItem FromObjectRef(object obj)
+        {
+            return new StackItem { _objref = obj, _kind = StackValueKind.ObjRef };
+        }
+
+        public object AsObjectRef()
+        {
+            Debug.Assert(_kind == StackValueKind.ObjRef);
+            return _objref;
+        }
+    }
+}