Merge pull request #2524 from dotnet/nmirror

Merge nmirror to master

9 files changed, 45 insertions, 88 deletions

diff --git a/src/System.Private.CoreLib/src/System.Private.CoreLib.csproj b/src/System.Private.CoreLib/src/System.Private.CoreLib.csproj
index 15ea8ef11..baf7c70b5 100644
--- a/src/System.Private.CoreLib/src/System.Private.CoreLib.csproj
+++ b/src/System.Private.CoreLib/src/System.Private.CoreLib.csproj
@@ -222,6 +222,7 @@
     <Compile Include="System\BadImageFormatException.cs" />
     <Compile Include="System\Boolean.cs" />
     <Compile Include="System\Buffer.cs" />
+    <Compile Include="System\ByReference.cs" />
     <Compile Include="System\Byte.cs" />
     <Compile Include="System\Char.cs" />
     <Compile Include="System\CharEnumerator.cs" />
diff --git a/src/System.Private.CoreLib/src/System/ByReference.cs b/src/System.Private.CoreLib/src/System/ByReference.cs
new file mode 100644
index 000000000..d0129c2ee
--- /dev/null
+++ b/src/System.Private.CoreLib/src/System/ByReference.cs
@@ -0,0 +1,41 @@
+// 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.Runtime.CompilerServices;
+
+namespace System
+{
+    // ByReference<T> is meant to be used to represent "ref T" fields. It is working
+    // around lack of first class support for byref fields in C# and IL. The JIT and 
+    // type loader have special handling for it that turns it into a thin wrapper around ref T.
+    [StackOnly]
+    internal struct ByReference<T>
+    {
+        // CS0169: The private field '{blah}' is never used
+#pragma warning disable 169
+        private IntPtr _value;
+#pragma warning restore
+
+        [Intrinsic]
+        public ByReference(ref T value)
+        {
+            // Implemented as a JIT intrinsic - This default implementation is for 
+            // completeness and to provide a concrete error if called via reflection
+            // or if intrinsic is missed.
+            throw new System.PlatformNotSupportedException();
+        }
+
+        public ref T Value
+        {
+            [Intrinsic]
+            get
+            {
+                // Implemented as a JIT intrinsic - This default implementation is for 
+                // completeness and to provide a concrete error if called via reflection
+                // or if the intrinsic is missed.
+                throw new System.PlatformNotSupportedException();
+            }
+        }
+    }
+}
diff --git a/src/System.Private.CoreLib/src/System/Environment.cs b/src/System.Private.CoreLib/src/System/Environment.cs
index 274c4e2a4..41d5dc038 100644
--- a/src/System.Private.CoreLib/src/System/Environment.cs
+++ b/src/System.Private.CoreLib/src/System/Environment.cs
@@ -33,9 +33,6 @@ namespace System
         Machine = 2,
     }
 
-    // Environment is marked as Eager to allow Lock to read the current
-    // thread ID, since Lock is used in ClassConstructorRunner.Cctor.GetCctor
-    [EagerOrderedStaticConstructor(EagerStaticConstructorOrder.SystemEnvironment)]
     public static partial class Environment
     {
         /*==================================TickCount===================================
diff --git a/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/ClassConstructorRunner.cs b/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/ClassConstructorRunner.cs
index 1b917fb94..f2f9ff581 100644
--- a/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/ClassConstructorRunner.cs
+++ b/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/ClassConstructorRunner.cs
@@ -13,9 +13,6 @@ using Internal.Runtime.CompilerHelpers;
 
 namespace System.Runtime.CompilerServices
 {
-    // Marked [EagerOrderedStaticConstructor] because Cctor.GetCctor
-    // uses _cctorGlobalLock
-    [EagerOrderedStaticConstructor(EagerStaticConstructorOrder.CompilerServicesClassConstructorRunner)]
     internal static partial class ClassConstructorRunner
     {
         //==============================================================================================================
@@ -482,17 +479,7 @@ namespace System.Runtime.CompilerServices
         private static int s_cctorArraysCount;
         private static int s_count;
 
-        //
-        // CoreRT calls Initialize directly for all types its needs that typically have EagerOrderedStaticConstructor
-        // attributes. To retain compatibility, please ensure static initialization is not done inline, and instead
-        // added to Initialize.
-        //
-#if !CORERT
-        static ClassConstructorRunner()
-        {
-            Initialize();
-        }
-#endif
+        // Eager construction called from LibraryInitialize Cctor.GetCctor uses _cctorGlobalLock.
         internal static void Initialize()
         {
             s_cctorArrays = new Cctor[10][];
diff --git a/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/EagerOrderedStaticConstructorAttribute.cs b/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/EagerOrderedStaticConstructorAttribute.cs
index ba4279c43..f3a699b17 100644
--- a/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/EagerOrderedStaticConstructorAttribute.cs
+++ b/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/EagerOrderedStaticConstructorAttribute.cs
@@ -22,19 +22,6 @@ namespace System.Runtime.CompilerServices
 
     public enum EagerStaticConstructorOrder : int
     {
-        // System.Private.CoreLib
-        SystemString,
-        SystemPreallocatedOutOfMemoryException,
-        SystemEnvironment, // ClassConstructorRunner.Cctor.GetCctor use Lock which inturn use current threadID , so System.Environment
-                           // should come before CompilerServicesClassConstructorRunnerCctor
-        CompilerServicesClassConstructorRunnerCctor,
-        CompilerServicesClassConstructorRunner,
-
-        // System.Private.TypeLoader  
-        RuntimeTypeHandleEqualityComparer,
-        TypeLoaderEnvironment,
-        SystemRuntimeTypeLoaderExports,
-
         // Interop
         InteropHeap,
         VtableIUnknown,
diff --git a/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/InternalCompilerAttributes.cs b/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/InternalCompilerAttributes.cs
index 298b4e466..3ad095e91 100644
--- a/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/InternalCompilerAttributes.cs
+++ b/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/InternalCompilerAttributes.cs
@@ -21,21 +21,4 @@ namespace System.Runtime.CompilerServices
 
     [AttributeUsage(AttributeTargets.Struct)]
     public sealed class StackOnlyAttribute : Attribute { }
-
-#if false // Unused right now. It is likely going to be useful for Span<T> implementation.
-    // This is a dummy class to be replaced by the compiler with a ref T
-    // It has to be a dummy class to avoid complicated type substitution
-    // and other complications in the compiler.
-    public sealed class ByReference<T>
-    {
-        //
-        // Managed pointer creation
-        //
-        [Intrinsic]
-        public static extern ByReference<T> FromRef(ref T source);
-
-        [Intrinsic]
-        public static extern ref T ToRef(ByReference<T> source);
-    }
-#endif
 }
diff --git a/src/System.Private.CoreLib/src/System/Runtime/TypeLoaderExports.cs b/src/System.Private.CoreLib/src/System/Runtime/TypeLoaderExports.cs
index 57e8efd79..64b50165e 100644
--- a/src/System.Private.CoreLib/src/System/Runtime/TypeLoaderExports.cs
+++ b/src/System.Private.CoreLib/src/System/Runtime/TypeLoaderExports.cs
@@ -11,8 +11,6 @@ using System.Runtime.InteropServices;
 
 namespace System.Runtime
 {
-    // Initialize the cache eagerly to avoid null checks
-    [EagerOrderedStaticConstructor(EagerStaticConstructorOrder.SystemRuntimeTypeLoaderExports)]
     public static class TypeLoaderExports
     {
         [RuntimeExport("GetThreadStaticsForDynamicType")]
@@ -80,18 +78,6 @@ namespace System.Runtime
         private volatile static IntPtr[] s_resolutionFunctionPointers;
         private static int s_nextResolutionFunctionPointerIndex;
 
-        //
-        // CoreRT calls Initialize directly for all types its needs that typically have EagerOrderedStaticConstructor
-        // attributes. To retain compatibility, please ensure static initialization is not done inline, and instead
-        // added to Initialize.
-        //
-#if !CORERT
-        static TypeLoaderExports()
-        {
-            Initialize();
-        }
-#endif
-
         internal static void Initialize()
         {
             s_cache = new Entry[1];
diff --git a/src/System.Private.CoreLib/src/System/RuntimeExceptionHelpers.cs b/src/System.Private.CoreLib/src/System/RuntimeExceptionHelpers.cs
index c53f1a251..1a47b20a7 100644
--- a/src/System.Private.CoreLib/src/System/RuntimeExceptionHelpers.cs
+++ b/src/System.Private.CoreLib/src/System/RuntimeExceptionHelpers.cs
@@ -13,24 +13,11 @@ using Internal.Runtime.Augments;
 
 namespace System
 {
-    // Eagerly preallocate instance of out of memory exception to avoid infinite recursion once we run out of memory
-    [EagerOrderedStaticConstructor(EagerStaticConstructorOrder.SystemPreallocatedOutOfMemoryException)]
     internal class PreallocatedOutOfMemoryException
     {
         public static OutOfMemoryException Instance { get; private set; }
 
-        //
-        // CoreRT calls Initialize directly for all types its needs that typically have EagerOrderedStaticConstructor
-        // attributes. To retain compatibility, please ensure static initialization is not done inline, and instead
-        // added to Initialize.
-        //
-#if !CORERT
-        static PreallocatedOutOfMemoryException()
-        {
-            Initialize();
-        }
-#endif
-
+        // Eagerly preallocate instance of out of memory exception to avoid infinite recursion once we run out of memory
         internal static void Initialize()
         {
              Instance = new OutOfMemoryException(message: null);  // Cannot call the nullary constructor as that triggers non-trivial resource manager logic.
diff --git a/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.cs b/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.cs
index b6309bd22..addf2ed12 100644
--- a/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.cs
+++ b/src/System.Private.TypeLoader/src/Internal/Runtime/TypeLoader/TypeLoaderEnvironment.cs
@@ -86,7 +86,6 @@ namespace Internal.Runtime.TypeLoader
         }
     }
 
-    [EagerOrderedStaticConstructor(EagerStaticConstructorOrder.TypeLoaderEnvironment)]
     public sealed partial class TypeLoaderEnvironment
     {
         [ThreadStatic]
@@ -107,18 +106,7 @@ namespace Internal.Runtime.TypeLoader
         [ThreadStatic]
         private static LowLevelDictionary<IntPtr, NativeReader> t_moduleNativeReaders;
 
-        //
-        // CoreRT calls Initialize directly for all types its needs that typically have EagerOrderedStaticConstructor
-        // attributes. To retain compatibility, please ensure static initialization is not done inline, and instead
-        // added to Initialize.
-        //
-#if !CORERT
-        static TypeLoaderEnvironment()
-        {
-            Initialize();
-        }
-#endif
-
+        // Eager initialization called from LibraryInitializer for the assembly.
         internal static void Initialize()
         {
             Instance = new TypeLoaderEnvironment();