Merge pull request #18645 from tgiphil/readonly

Changed internal value to readonly for primitive types

18 files changed, 45 insertions, 30 deletions

diff --git a/src/System.Private.CoreLib/shared/Internal/Runtime/CompilerServices/Unsafe.cs b/src/System.Private.CoreLib/shared/Internal/Runtime/CompilerServices/Unsafe.cs
index aeff3ce2ca..03d3f85211 100644
--- a/src/System.Private.CoreLib/shared/Internal/Runtime/CompilerServices/Unsafe.cs
+++ b/src/System.Private.CoreLib/shared/Internal/Runtime/CompilerServices/Unsafe.cs
@@ -358,6 +358,17 @@ namespace Internal.Runtime.CompilerServices
         }
 
         /// <summary>
+        /// Reinterprets the given location as a reference to a value of type <typeparamref name="T"/>.
+        /// </summary>
+        [Intrinsic]
+        [NonVersionable]
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static ref T AsRef<T>(in T source)
+        {
+            throw new PlatformNotSupportedException();
+        }
+
+        /// <summary>
         /// Determines the byte offset from origin to target from the given references.
         /// </summary>
         [Intrinsic]
diff --git a/src/System.Private.CoreLib/shared/System/Boolean.cs b/src/System.Private.CoreLib/shared/System/Boolean.cs
index dbc7bd75ee..7ec9227f1b 100644
--- a/src/System.Private.CoreLib/shared/System/Boolean.cs
+++ b/src/System.Private.CoreLib/shared/System/Boolean.cs
@@ -19,12 +19,12 @@ namespace System
 {
     [Serializable]
     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
-    public struct Boolean : IComparable, IConvertible, IComparable<bool>, IEquatable<bool>
+    public readonly struct Boolean : IComparable, IConvertible, IComparable<bool>, IEquatable<bool>
     {
         //
         // Member Variables
         //
-        private bool m_value; // Do not rename (binary serialization)
+        private readonly bool m_value; // Do not rename (binary serialization)
 
         // The true value.
         //
diff --git a/src/System.Private.CoreLib/shared/System/Byte.cs b/src/System.Private.CoreLib/shared/System/Byte.cs
index 64512b0fee..5e8580642b 100644
--- a/src/System.Private.CoreLib/shared/System/Byte.cs
+++ b/src/System.Private.CoreLib/shared/System/Byte.cs
@@ -12,9 +12,9 @@ namespace System
     [Serializable]
     [StructLayout(LayoutKind.Sequential)]
     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
-    public struct Byte : IComparable, IConvertible, IFormattable, IComparable<byte>, IEquatable<byte>, ISpanFormattable
+    public readonly struct Byte : IComparable, IConvertible, IFormattable, IComparable<byte>, IEquatable<byte>, ISpanFormattable
     {
-        private byte m_value; // Do not rename (binary serialization)
+        private readonly byte m_value; // Do not rename (binary serialization)
 
         // The maximum value that a Byte may represent: 255.
         public const byte MaxValue = (byte)0xFF;
diff --git a/src/System.Private.CoreLib/shared/System/Char.cs b/src/System.Private.CoreLib/shared/System/Char.cs
index a3d2963402..8c743369b1 100644
--- a/src/System.Private.CoreLib/shared/System/Char.cs
+++ b/src/System.Private.CoreLib/shared/System/Char.cs
@@ -21,12 +21,12 @@ namespace System
     [Serializable]
     [StructLayout(LayoutKind.Sequential)]
     [System.Runtime.CompilerServices.TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")] 
-    public struct Char : IComparable, IComparable<char>, IEquatable<char>, IConvertible
+    public readonly struct Char : IComparable, IComparable<char>, IEquatable<char>, IConvertible
     {
         //
         // Member Variables
         //
-        private char m_value; // Do not rename (binary serialization)
+        private readonly char m_value; // Do not rename (binary serialization)
 
         //
         // Public Constants
diff --git a/src/System.Private.CoreLib/shared/System/Double.cs b/src/System.Private.CoreLib/shared/System/Double.cs
index 79021f22b8..69da2e34b7 100644
--- a/src/System.Private.CoreLib/shared/System/Double.cs
+++ b/src/System.Private.CoreLib/shared/System/Double.cs
@@ -26,7 +26,7 @@ namespace System
     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
     public struct Double : IComparable, IConvertible, IFormattable, IComparable<double>, IEquatable<double>, ISpanFormattable
     {
-        private double m_value; // Do not rename (binary serialization)
+        private readonly double m_value; // Do not rename (binary serialization)
 
         //
         // Public Constants
@@ -226,7 +226,7 @@ namespace System
         [MethodImpl(MethodImplOptions.AggressiveInlining)] // 64-bit constants make the IL unusually large that makes the inliner to reject the method
         public override int GetHashCode()
         {
-            var bits = Unsafe.As<double, long>(ref m_value);
+            var bits = Unsafe.As<double, long>(ref Unsafe.AsRef(in m_value));
 
             // Optimized check for IsNan() || IsZero()
             if (((bits - 1) & 0x7FFFFFFFFFFFFFFF) >= 0x7FF0000000000000)
diff --git a/src/System.Private.CoreLib/shared/System/Int16.cs b/src/System.Private.CoreLib/shared/System/Int16.cs
index 2993337a74..4973299763 100644
--- a/src/System.Private.CoreLib/shared/System/Int16.cs
+++ b/src/System.Private.CoreLib/shared/System/Int16.cs
@@ -12,9 +12,9 @@ namespace System
     [Serializable]
     [StructLayout(LayoutKind.Sequential)]
     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
-    public struct Int16 : IComparable, IConvertible, IFormattable, IComparable<short>, IEquatable<short>, ISpanFormattable
+    public readonly struct Int16 : IComparable, IConvertible, IFormattable, IComparable<short>, IEquatable<short>, ISpanFormattable
     {
-        private short m_value; // Do not rename (binary serialization)
+        private readonly short m_value; // Do not rename (binary serialization)
 
         public const short MaxValue = (short)0x7FFF;
         public const short MinValue = unchecked((short)0x8000);
diff --git a/src/System.Private.CoreLib/shared/System/Int32.cs b/src/System.Private.CoreLib/shared/System/Int32.cs
index 5c40812c0a..1d0aefe73c 100644
--- a/src/System.Private.CoreLib/shared/System/Int32.cs
+++ b/src/System.Private.CoreLib/shared/System/Int32.cs
@@ -12,9 +12,9 @@ namespace System
     [Serializable]
     [StructLayout(LayoutKind.Sequential)]
     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
-    public struct Int32 : IComparable, IConvertible, IFormattable, IComparable<int>, IEquatable<int>, ISpanFormattable
+    public readonly struct Int32 : IComparable, IConvertible, IFormattable, IComparable<int>, IEquatable<int>, ISpanFormattable
     {
-        private int m_value; // Do not rename (binary serialization)
+        private readonly int m_value; // Do not rename (binary serialization)
 
         public const int MaxValue = 0x7fffffff;
         public const int MinValue = unchecked((int)0x80000000);
diff --git a/src/System.Private.CoreLib/shared/System/Int64.cs b/src/System.Private.CoreLib/shared/System/Int64.cs
index 29198781d7..62c9ffd4fe 100644
--- a/src/System.Private.CoreLib/shared/System/Int64.cs
+++ b/src/System.Private.CoreLib/shared/System/Int64.cs
@@ -12,9 +12,9 @@ namespace System
     [Serializable]
     [StructLayout(LayoutKind.Sequential)]
     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
-    public struct Int64 : IComparable, IConvertible, IFormattable, IComparable<long>, IEquatable<long>, ISpanFormattable
+    public readonly struct Int64 : IComparable, IConvertible, IFormattable, IComparable<long>, IEquatable<long>, ISpanFormattable
     {
-        private long m_value; // Do not rename (binary serialization)
+        private readonly long m_value; // Do not rename (binary serialization)
 
         public const long MaxValue = 0x7fffffffffffffffL;
         public const long MinValue = unchecked((long)0x8000000000000000L);
diff --git a/src/System.Private.CoreLib/shared/System/IntPtr.cs b/src/System.Private.CoreLib/shared/System/IntPtr.cs
index c5419a96e0..f79334a96b 100644
--- a/src/System.Private.CoreLib/shared/System/IntPtr.cs
+++ b/src/System.Private.CoreLib/shared/System/IntPtr.cs
@@ -17,13 +17,13 @@ namespace System
 {
     [Serializable]
     [System.Runtime.CompilerServices.TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
-    public struct IntPtr : IEquatable<IntPtr>, ISerializable
+    public readonly struct IntPtr : IEquatable<IntPtr>, ISerializable
     {
         // WARNING: We allow diagnostic tools to directly inspect this member (_value). 
         // See https://github.com/dotnet/corert/blob/master/Documentation/design-docs/diagnostics/diagnostics-tools-contract.md for more details. 
         // Please do not change the type, the name, or the semantic usage of this member without understanding the implication for tools. 
         // Get in touch with the diagnostics team if you have questions.
-        private unsafe void* _value; // Do not rename (binary serialization)
+        private readonly unsafe void* _value; // Do not rename (binary serialization)
 
         [Intrinsic]
         public static readonly IntPtr Zero;
diff --git a/src/System.Private.CoreLib/shared/System/SByte.cs b/src/System.Private.CoreLib/shared/System/SByte.cs
index e3c6d170a1..e347e3b323 100644
--- a/src/System.Private.CoreLib/shared/System/SByte.cs
+++ b/src/System.Private.CoreLib/shared/System/SByte.cs
@@ -12,9 +12,9 @@ namespace System
     [Serializable]
     [CLSCompliant(false)]    [StructLayout(LayoutKind.Sequential)]
     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
-    public struct SByte : IComparable, IConvertible, IFormattable, IComparable<sbyte>, IEquatable<sbyte>, ISpanFormattable
+    public readonly struct SByte : IComparable, IConvertible, IFormattable, IComparable<sbyte>, IEquatable<sbyte>, ISpanFormattable
     {
-        private sbyte m_value; // Do not rename (binary serialization)
+        private readonly sbyte m_value; // Do not rename (binary serialization)
 
         // The maximum value that a Byte may represent: 127.
         public const sbyte MaxValue = (sbyte)0x7F;
diff --git a/src/System.Private.CoreLib/shared/System/Single.cs b/src/System.Private.CoreLib/shared/System/Single.cs
index 1a778c957c..7dddb029a8 100644
--- a/src/System.Private.CoreLib/shared/System/Single.cs
+++ b/src/System.Private.CoreLib/shared/System/Single.cs
@@ -25,7 +25,7 @@ namespace System
     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
     public struct Single : IComparable, IConvertible, IFormattable, IComparable<float>, IEquatable<float>, ISpanFormattable
     {
-        private float m_value; // Do not rename (binary serialization)
+        private readonly float m_value; // Do not rename (binary serialization)
 
         //
         // Public constants
@@ -217,7 +217,7 @@ namespace System
 
         public override int GetHashCode()
         {
-            var bits = Unsafe.As<float, int>(ref m_value);
+            var bits = Unsafe.As<float, int>(ref Unsafe.AsRef(in m_value));
 
             // Optimized check for IsNan() || IsZero()
             if (((bits - 1) & 0x7FFFFFFF) >= 0x7F800000)
diff --git a/src/System.Private.CoreLib/shared/System/UInt16.cs b/src/System.Private.CoreLib/shared/System/UInt16.cs
index cd09894c62..f9ef1f6a62 100644
--- a/src/System.Private.CoreLib/shared/System/UInt16.cs
+++ b/src/System.Private.CoreLib/shared/System/UInt16.cs
@@ -13,9 +13,9 @@ namespace System
     [CLSCompliant(false)]
     [StructLayout(LayoutKind.Sequential)]
     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
-    public struct UInt16 : IComparable, IConvertible, IFormattable, IComparable<ushort>, IEquatable<ushort>, ISpanFormattable
+    public readonly struct UInt16 : IComparable, IConvertible, IFormattable, IComparable<ushort>, IEquatable<ushort>, ISpanFormattable
     {
-        private ushort m_value; // Do not rename (binary serialization)
+        private readonly ushort m_value; // Do not rename (binary serialization)
 
         public const ushort MaxValue = (ushort)0xFFFF;
         public const ushort MinValue = 0;
diff --git a/src/System.Private.CoreLib/shared/System/UInt32.cs b/src/System.Private.CoreLib/shared/System/UInt32.cs
index d72a0a1956..5ed193e956 100644
--- a/src/System.Private.CoreLib/shared/System/UInt32.cs
+++ b/src/System.Private.CoreLib/shared/System/UInt32.cs
@@ -13,9 +13,9 @@ namespace System
     [CLSCompliant(false)]
     [StructLayout(LayoutKind.Sequential)]
     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
-    public struct UInt32 : IComparable, IConvertible, IFormattable, IComparable<uint>, IEquatable<uint>, ISpanFormattable
+    public readonly struct UInt32 : IComparable, IConvertible, IFormattable, IComparable<uint>, IEquatable<uint>, ISpanFormattable
     {
-        private uint m_value; // Do not rename (binary serialization)
+        private readonly uint m_value; // Do not rename (binary serialization)
 
         public const uint MaxValue = (uint)0xffffffff;
         public const uint MinValue = 0U;
diff --git a/src/System.Private.CoreLib/shared/System/UInt64.cs b/src/System.Private.CoreLib/shared/System/UInt64.cs
index 3b1010a51f..6abd76da21 100644
--- a/src/System.Private.CoreLib/shared/System/UInt64.cs
+++ b/src/System.Private.CoreLib/shared/System/UInt64.cs
@@ -13,9 +13,9 @@ namespace System
     [CLSCompliant(false)]
     [StructLayout(LayoutKind.Sequential)]
     [TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
-    public struct UInt64 : IComparable, IConvertible, IFormattable, IComparable<ulong>, IEquatable<ulong>, ISpanFormattable
+    public readonly struct UInt64 : IComparable, IConvertible, IFormattable, IComparable<ulong>, IEquatable<ulong>, ISpanFormattable
     {
-        private ulong m_value; // Do not rename (binary serialization)
+        private readonly ulong m_value; // Do not rename (binary serialization)
 
         public const ulong MaxValue = (ulong)0xffffffffffffffffL;
         public const ulong MinValue = 0x0;
diff --git a/src/System.Private.CoreLib/shared/System/UIntPtr.cs b/src/System.Private.CoreLib/shared/System/UIntPtr.cs
index 484eef4b61..9534f4f872 100644
--- a/src/System.Private.CoreLib/shared/System/UIntPtr.cs
+++ b/src/System.Private.CoreLib/shared/System/UIntPtr.cs
@@ -18,9 +18,9 @@ namespace System
     [Serializable]
     [CLSCompliant(false)]
     [System.Runtime.CompilerServices.TypeForwardedFrom("mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
-    public struct UIntPtr : IEquatable<UIntPtr>, ISerializable
+    public readonly struct UIntPtr : IEquatable<UIntPtr>, ISerializable
     {
-        private unsafe void* _value; // Do not rename (binary serialization)
+        private readonly unsafe void* _value; // Do not rename (binary serialization)
 
         [Intrinsic]
         public static readonly UIntPtr Zero;
diff --git a/src/vm/jitinterface.cpp b/src/vm/jitinterface.cpp
index ccd99df9ac..c532f201d4 100644
--- a/src/vm/jitinterface.cpp
+++ b/src/vm/jitinterface.cpp
@@ -7047,7 +7047,8 @@ bool getILIntrinsicImplementationForUnsafe(MethodDesc * ftn,
     }
     else if (tk == MscorlibBinder::GetMethod(METHOD__UNSAFE__BYREF_AS)->GetMemberDef() ||
              tk == MscorlibBinder::GetMethod(METHOD__UNSAFE__OBJECT_AS)->GetMemberDef() ||
-             tk == MscorlibBinder::GetMethod(METHOD__UNSAFE__AS_REF)->GetMemberDef())
+             tk == MscorlibBinder::GetMethod(METHOD__UNSAFE__AS_REF_POINTER)->GetMemberDef() ||
+             tk == MscorlibBinder::GetMethod(METHOD__UNSAFE__AS_REF_IN)->GetMemberDef())
     {
         // Return the argument that was passed in.
         static const BYTE ilcode[] = { CEE_LDARG_0, CEE_RET };
diff --git a/src/vm/metasig.h b/src/vm/metasig.h
index 49e26f17e9..b3a4139a7c 100644
--- a/src/vm/metasig.h
+++ b/src/vm/metasig.h
@@ -290,6 +290,8 @@ DEFINE_METASIG(GM(RefByte_T_RetVoid, IMAGE_CEE_CS_CALLCONV_DEFAULT, 1, r(b) M(0)
 DEFINE_METASIG(GM(PtrVoid_RetT, IMAGE_CEE_CS_CALLCONV_DEFAULT, 1, P(v), M(0)))
 DEFINE_METASIG(GM(PtrVoid_T_RetVoid, IMAGE_CEE_CS_CALLCONV_DEFAULT, 1, P(v) M(0), v))
 
+DEFINE_METASIG(GM(RefT_RetRefT, IMAGE_CEE_CS_CALLCONV_DEFAULT, 1, r(M(0)), r(M(0))))
+DEFINE_METASIG(GM(VoidPtr_RetRefT, IMAGE_CEE_CS_CALLCONV_DEFAULT, 1, P(v), r(M(0))))
 DEFINE_METASIG(GM(RefTFrom_RetRefTTo, IMAGE_CEE_CS_CALLCONV_DEFAULT, 2, r(M(0)), r(M(1))))
 DEFINE_METASIG(GM(Obj_RetT, IMAGE_CEE_CS_CALLCONV_DEFAULT, 1, j, M(0)))
 DEFINE_METASIG(GM(RefT_Int_RetRefT, IMAGE_CEE_CS_CALLCONV_DEFAULT, 1, r(M(0)) i, r(M(0))))
diff --git a/src/vm/mscorlib.h b/src/vm/mscorlib.h
index c9715e1396..c57290ff12 100644
--- a/src/vm/mscorlib.h
+++ b/src/vm/mscorlib.h
@@ -775,7 +775,8 @@ DEFINE_METHOD(JIT_HELPERS,          GET_RAW_SZ_ARRAY_DATA,  GetRawSzArrayData, N
 
 DEFINE_CLASS(UNSAFE,                InternalCompilerServices,       Unsafe)
 DEFINE_METHOD(UNSAFE,               AS_POINTER,             AsPointer, NoSig)
-DEFINE_METHOD(UNSAFE,               AS_REF,                 AsRef, NoSig)
+DEFINE_METHOD(UNSAFE,               AS_REF_IN,              AsRef, GM_RefT_RetRefT)
+DEFINE_METHOD(UNSAFE,               AS_REF_POINTER,         AsRef, GM_VoidPtr_RetRefT)
 DEFINE_METHOD(UNSAFE,               SIZEOF,                 SizeOf, NoSig)
 DEFINE_METHOD(UNSAFE,               BYREF_AS,               As, GM_RefTFrom_RetRefTTo)
 DEFINE_METHOD(UNSAFE,               OBJECT_AS,              As, GM_Obj_RetT)