[mono] Hot Reload: initial push to support adding lambdas

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddLambdaCapturingThis/AddLambdaCapturingThis.cs

@@ -7,19 +7,21 @@ namespace System.Reflection.Metadata.ApplyUpdate.Test
 {
     public class AddLambdaCapturingThis
     {
-	public AddLambdaCapturingThis () {
-	    field = "abcd";
-	}
+        public AddLambdaCapturingThis()
+        {
+            field = "abcd";
+        }
 
-	public string GetField => field;
+        public string GetField => field;
 
-	private string field;
+        private string field;
 
-	public string TestMethod () {
-	    // capture 'this' but no locals
-	    Func<string,string> fn = s => field;
-	    return "123";
-	}
+        public string TestMethod()
+        {
+            // capture 'this' but no locals
+            Func<string,string> fn = s => field;
+            return "123";
+        }
 
     }
 }

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddLambdaCapturingThis/AddLambdaCapturingThis_v1.cs

@@ -7,23 +7,21 @@ namespace System.Reflection.Metadata.ApplyUpdate.Test
 {
     public class AddLambdaCapturingThis
     {
-	public AddLambdaCapturingThis () {
-	    field = "abcd";
-	}
+        public AddLambdaCapturingThis()
+        {
+            field = "abcd";
+        }
 
-	public string GetField => field;
+        public string GetField => field;
 
-	private string field;
-
-	public string TestMethod () {
-	    // capture 'this' but no locals
-	    Func<string,string> fn = s => NewMethod (s + field, 42);
-	    return fn ("123");
-	}
-
-	private string NewMethod (string s, int i) {
-	    return i.ToString() + s;
-	}
+        private string field;
 
+        public string TestMethod()
+        {
+            // capture 'this' but no locals
+            Func<string,string> fn = s => field;
+            Func<string,string> fn2 = s => "42" + s + field;
+            return fn2 ("123");
+        }
     }
 }

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddNestedClass/AddNestedClass.cs

@@ -0,0 +1,20 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+using System;
+
+
+namespace System.Reflection.Metadata.ApplyUpdate.Test
+{
+    public class AddNestedClass
+    {
+        public AddNestedClass()
+        {
+        }
+
+        public string TestMethod()
+        {
+            return "123";
+        }
+
+    }
+}

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddNestedClass/AddNestedClass_v1.cs

@@ -0,0 +1,29 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+using System;
+
+
+namespace System.Reflection.Metadata.ApplyUpdate.Test
+{
+    public class AddNestedClass
+    {
+        public AddNestedClass()
+        {
+        }
+
+        public string TestMethod()
+        {
+            var n = new Nested();
+            n.f = "123";
+            return n.M();
+        }
+
+        private class Nested {
+            public Nested() { }
+            internal string f;
+            public string M () {
+                return f + "456";
+            }
+        }
+    }
+}

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddNestedClass/System.Reflection.Metadata.ApplyUpdate.Test.AddNestedClass.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <RootNamespace>System.Runtime.Loader.Tests</RootNamespace>
+    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TestRuntime>true</TestRuntime>
+    <DeltaScript>deltascript.json</DeltaScript>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="AddNestedClass.cs" />
+  </ItemGroup>
+</Project>

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddNestedClass/deltascript.json

@@ -0,0 +1,6 @@
+{
+    "changes": [
+        {"document": "AddNestedClass.cs", "update": "AddNestedClass_v1.cs"},
+    ]
+}
+

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddStaticField/AddStaticField.cs

@@ -0,0 +1,22 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+using System;
+
+
+namespace System.Reflection.Metadata.ApplyUpdate.Test
+{
+    public class AddStaticField
+    {
+        public AddStaticField () {
+        }
+
+        public string GetField => s_field;
+
+        private static string s_field;
+
+        public void TestMethod () {
+            s_field = "abcd";
+        }
+
+    }
+}

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddStaticField/AddStaticField_v1.cs

@@ -0,0 +1,25 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+using System;
+
+
+namespace System.Reflection.Metadata.ApplyUpdate.Test
+{
+    public class AddStaticField
+    {
+        public AddStaticField () {
+        }
+
+        public string GetField => s_field2;
+
+        private static string s_field;
+
+        private static string s_field2;
+
+        public void TestMethod () {
+            s_field = "spqr";
+            s_field2 = "4567";
+        }
+
+    }
+}

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddStaticField/System.Reflection.Metadata.ApplyUpdate.Test.AddStaticField.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <RootNamespace>System.Runtime.Loader.Tests</RootNamespace>
+    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TestRuntime>true</TestRuntime>
+    <DeltaScript>deltascript.json</DeltaScript>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="AddStaticField.cs" />
+  </ItemGroup>
+</Project>

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddStaticField/deltascript.json

@@ -0,0 +1,6 @@
+{
+    "changes": [
+        {"document": "AddStaticField.cs", "update": "AddStaticField_v1.cs"},
+    ]
+}
+

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddStaticLambda/AddStaticLambda.cs

@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+using System;
+
+
+namespace System.Reflection.Metadata.ApplyUpdate.Test
+{
+    public class AddStaticLambda
+    {
+        public string TestMethod()
+	{
+            return "abcd";
+        }
+
+        public string Double(Func<string,string> f) => f("") + f("1");
+
+    }
+}

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddStaticLambda/AddStaticLambda_v1.cs

@@ -0,0 +1,18 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+using System;
+
+
+namespace System.Reflection.Metadata.ApplyUpdate.Test
+{
+    public class AddStaticLambda
+    {
+        public string TestMethod()
+	{
+            return Double(static (s) => s + "abcd");
+        }
+
+        public string Double(Func<string,string> f) => f("") + f("1");
+
+    }
+}

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddStaticLambda/System.Reflection.Metadata.ApplyUpdate.Test.AddStaticLambda.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <RootNamespace>System.Runtime.Loader.Tests</RootNamespace>
+    <TargetFrameworks>$(NetCoreAppCurrent)</TargetFrameworks>
+    <TestRuntime>true</TestRuntime>
+    <DeltaScript>deltascript.json</DeltaScript>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="AddStaticLambda.cs" />
+  </ItemGroup>
+</Project>

src/libraries/System.Runtime.Loader/tests/ApplyUpdate/System.Reflection.Metadata.ApplyUpdate.Test.AddStaticLambda/deltascript.json

@@ -0,0 +1,6 @@
+{
+    "changes": [
+        {"document": "AddStaticLambda.cs", "update": "AddStaticLambda_v1.cs"},
+    ]
+}
+

src/libraries/System.Runtime.Loader/tests/ApplyUpdateTest.cs

@@ -71,6 +71,7 @@ void LambdaBodyChange()
         [ActiveIssue("https://github.com/dotnet/runtime/issues/54617", typeof(PlatformDetection), nameof(PlatformDetection.IsBrowser), nameof(PlatformDetection.IsMonoAOT))] 
         void LambdaCapturesThis()
         {
+            // Tests that changes to the body of a lambda that captures 'this' is supported.
             ApplyUpdateUtil.TestCase(static () =>
             {
                 var assm = typeof (ApplyUpdate.Test.LambdaCapturesThis).Assembly;
@@ -263,25 +264,92 @@ public void AsyncMethodChanges()
             });
         }
 
-	[ActiveIssue ("https://github.com/dotnet/runtime/issues/50249", TestRuntimes.Mono)]
-	[ConditionalFact(typeof(ApplyUpdateUtil), nameof(ApplyUpdateUtil.IsSupported))]
-	public static void TestAddLambdaCapturingThis()
-	{
-	    ApplyUpdateUtil.TestCase(static () =>
-	    {
-		var assm = typeof(System.Reflection.Metadata.ApplyUpdate.Test.AddLambdaCapturingThis).Assembly;
+        [ConditionalFact(typeof(ApplyUpdateUtil), nameof(ApplyUpdateUtil.IsSupported))]
+        public static void TestAddLambdaCapturingThis()
+        {
+            // Test that adding a lambda that captures 'this' (to a method that already has a lambda that captures 'this') is supported
+            ApplyUpdateUtil.TestCase(static () =>
+            {
+                var assm = typeof(System.Reflection.Metadata.ApplyUpdate.Test.AddLambdaCapturingThis).Assembly;
+
+                var x = new System.Reflection.Metadata.ApplyUpdate.Test.AddLambdaCapturingThis();
+
+                Assert.Equal("123", x.TestMethod());
+
+                ApplyUpdateUtil.ApplyUpdate(assm);
+
+                string result = x.TestMethod();
+                Assert.Equal("42123abcd", result);
+            });
+        }
+
+        [ConditionalFact(typeof(ApplyUpdateUtil), nameof(ApplyUpdateUtil.IsSupported))]
+        public static void TestAddStaticField()
+        {
+            // Test that adding a new static field to an existing class is supported
+            ApplyUpdateUtil.TestCase(static () =>
+            {
+                var assm = typeof(System.Reflection.Metadata.ApplyUpdate.Test.AddStaticField).Assembly;
+
+                var x = new System.Reflection.Metadata.ApplyUpdate.Test.AddStaticField();
+
+                x.TestMethod();
+
+                Assert.Equal ("abcd", x.GetField);
+
+                ApplyUpdateUtil.ApplyUpdate(assm);
+
+                x.TestMethod();
+
+                string result = x.GetField;
+                Assert.Equal("4567", result);
+            });
+        }
+
+        [ActiveIssue("https://github.com/dotnet/runtime/issues/63643", TestRuntimes.Mono)]
+        [ConditionalFact(typeof(ApplyUpdateUtil), nameof(ApplyUpdateUtil.IsSupported))]
+        public static void TestAddNestedClass()
+        {
+            // Test that adding a new nested class to an existing class is supported
+            ApplyUpdateUtil.TestCase(static () =>
+            {
+                var assm = typeof(System.Reflection.Metadata.ApplyUpdate.Test.AddNestedClass).Assembly;
+
+                var x = new System.Reflection.Metadata.ApplyUpdate.Test.AddNestedClass();
+
+                var r = x.TestMethod();
+
+                Assert.Equal ("123", r);
+
+                ApplyUpdateUtil.ApplyUpdate(assm);
+
+                r = x.TestMethod();
 
-		var x = new System.Reflection.Metadata.ApplyUpdate.Test.AddLambdaCapturingThis();
+                Assert.Equal("123456", r);
+            });
+        }
+
+        [ConditionalFact(typeof(ApplyUpdateUtil), nameof(ApplyUpdateUtil.IsSupported))]
+        public static void TestAddStaticLambda()
+        {
+            // Test that adding a new static lambda to an existing method body is supported
+            ApplyUpdateUtil.TestCase(static () =>
+            {
+                var assm = typeof(System.Reflection.Metadata.ApplyUpdate.Test.AddStaticLambda).Assembly;
 
-		Assert.Equal("123", x.TestMethod());
+                var x = new System.Reflection.Metadata.ApplyUpdate.Test.AddStaticLambda();
 
-		ApplyUpdateUtil.ApplyUpdate(assm);
+                var r = x.TestMethod();
 
-		string result = x.TestMethod();
-		Assert.Equal("42123abcd", result);
-	    });
-	}
+                Assert.Equal ("abcd", r);
 
+                ApplyUpdateUtil.ApplyUpdate(assm);
+
+                r = x.TestMethod();
+
+                Assert.Equal("abcd1abcd", r);
+            });
+        }
 
         class NonRuntimeAssembly : Assembly
         {

src/libraries/System.Runtime.Loader/tests/System.Runtime.Loader.Tests.csproj

@@ -53,6 +53,9 @@
     <ProjectReference Include="ApplyUpdate\System.Reflection.Metadata.ApplyUpdate.Test.LambdaCapturesThis\System.Reflection.Metadata.ApplyUpdate.Test.LambdaCapturesThis.csproj" />
     <ProjectReference Include="ApplyUpdate\System.Reflection.Metadata.ApplyUpdate.Test.FirstCallAfterUpdate\System.Reflection.Metadata.ApplyUpdate.Test.FirstCallAfterUpdate.csproj" />
     <ProjectReference Include="ApplyUpdate\System.Reflection.Metadata.ApplyUpdate.Test.AddLambdaCapturingThis\System.Reflection.Metadata.ApplyUpdate.Test.AddLambdaCapturingThis.csproj" />
+    <ProjectReference Include="ApplyUpdate\System.Reflection.Metadata.ApplyUpdate.Test.AddStaticField\System.Reflection.Metadata.ApplyUpdate.Test.AddStaticField.csproj" />
+    <ProjectReference Include="ApplyUpdate\System.Reflection.Metadata.ApplyUpdate.Test.AddNestedClass\System.Reflection.Metadata.ApplyUpdate.Test.AddNestedClass.csproj" />
+    <ProjectReference Include="ApplyUpdate\System.Reflection.Metadata.ApplyUpdate.Test.AddStaticLambda\System.Reflection.Metadata.ApplyUpdate.Test.AddStaticLambda.csproj" />
   </ItemGroup>
   <ItemGroup Condition="'$(TargetOS)' == 'Browser'">
     <WasmFilesToIncludeFromPublishDir Include="$(AssemblyName).dll" />

src/mono/System.Private.CoreLib/System.Private.CoreLib.csproj

@@ -290,6 +290,7 @@
       <Compile Include="$(LibrariesProjectRoot)\System.Private.CoreLib\src\System\Threading\ThreadPoolBoundHandle.PlatformNotSupported.cs" />
   </ItemGroup>
   <ItemGroup>
+      <Compile Include="$(BclSourcesRoot)\Mono\HotReload.cs" />
       <Compile Include="$(BclSourcesRoot)\Mono\RuntimeStructs.cs" />
       <Compile Include="$(BclSourcesRoot)\Mono\RuntimeMarshal.cs" />
       <Compile Include="$(BclSourcesRoot)\Mono\SafeStringMarshal.cs" />