EnC: Block additions to MethodImpl table when targeting .NET Framework

src/Compilers/CSharp/Portable/CSharpResources.resx

@@ -1799,6 +1799,9 @@ If such a class is used as a base class and if the deriving class defines a dest
   <data name="ERR_DllImportOnInvalidMethod" xml:space="preserve">
     <value>The DllImport attribute must be specified on a method marked 'extern' that is either 'static' or an extension member</value>
   </data>
+  <data name="ERR_EncUpdateRequiresEmittingExplicitInterfaceImplementationNotSupportedByTheRuntime" xml:space="preserve">
+    <value>Update requires emitting explicit interface implementation, which is not supported by the runtime without restarting the application.</value>
+  </data>
   <data name="ERR_EncUpdateFailedMissingSymbol" xml:space="preserve">
     <value>Cannot emit update; {0} '{1}' is missing.</value>
   </data>

src/Compilers/CSharp/Portable/Emitter/EditAndContinue/PEDeltaAssemblyBuilder.cs

@@ -78,6 +78,7 @@ public PEDeltaAssemblyBuilder(
         public override SymbolChanges? EncSymbolChanges => _changes;
         public override EmitBaseline PreviousGeneration => _changes.DefinitionMap.Baseline;
         public override bool FieldRvaSupported => _options.EmitFieldRva;
+        public override bool MethodImplSupported => !_options.DisallowExplicitMethodImplementations;
 
         internal override Cci.ITypeReference EncTranslateLocalVariableType(TypeSymbol type, DiagnosticBag diagnostics)
         {

src/Compilers/CSharp/Portable/Emitter/Model/PEAssemblyBuilder.cs

@@ -693,6 +693,7 @@ internal sealed class PEAssemblyBuilder(
         public override EmitBaseline? PreviousGeneration => null;
         public override SymbolChanges? EncSymbolChanges => null;
         public override bool FieldRvaSupported => true;
+        public override bool MethodImplSupported => true;
 
         public override INamedTypeSymbolInternal? TryGetOrCreateSynthesizedHotReloadExceptionType()
             => null;

src/Compilers/CSharp/Portable/Emitter/Model/PENetModuleBuilder.cs

@@ -40,6 +40,7 @@ protected override void AddEmbeddedResourcesFromAddedModules(ArrayBuilder<Cci.Ma
         public override EmitBaseline? PreviousGeneration => null;
         public override SymbolChanges? EncSymbolChanges => null;
         public override bool FieldRvaSupported => true;
+        public override bool MethodImplSupported => true;
 
         public override INamedTypeSymbolInternal? TryGetOrCreateSynthesizedHotReloadExceptionType()
             => null;

src/Compilers/CSharp/Portable/Errors/ErrorCode.cs

@@ -2441,6 +2441,7 @@ internal enum ErrorCode
         ERR_AmbigOperator = 9342,
 
         ERR_UnexpectedArgumentListInBaseTypeWithoutParameterList = 9343,
+        ERR_EncUpdateRequiresEmittingExplicitInterfaceImplementationNotSupportedByTheRuntime = 9344,
 
         // Note: you will need to do the following after adding errors:
         //  1) Update ErrorFacts.IsBuildOnlyDiagnostic (src/Compilers/CSharp/Portable/Errors/ErrorFacts.cs)

src/Compilers/CSharp/Portable/Errors/ErrorFacts.cs

@@ -2548,6 +2548,7 @@ or ErrorCode.ERR_SingleInapplicableBinaryOperator
                 or ErrorCode.ERR_SingleInapplicableUnaryOperator
                 or ErrorCode.ERR_AmbigOperator
                 or ErrorCode.ERR_UnexpectedArgumentListInBaseTypeWithoutParameterList
+                or ErrorCode.ERR_EncUpdateRequiresEmittingExplicitInterfaceImplementationNotSupportedByTheRuntime
                     => false,
             };
 #pragma warning restore CS8524 // The switch expression does not handle some values of its input type (it is not exhaustive) involving an unnamed enum value.

src/Compilers/CSharp/Portable/Errors/MessageProvider.cs

@@ -253,6 +253,7 @@ public override void ReportDuplicateMetadataReferenceWeak(DiagnosticBag diagnost
         public override int ERR_InvalidDebugInfo => (int)ErrorCode.ERR_InvalidDebugInfo;
         public override int ERR_FunctionPointerTypesInAttributeNotSupported => (int)ErrorCode.ERR_FunctionPointerTypesInAttributeNotSupported;
         public override int ERR_DataSectionStringLiteralHashCollision => (int)ErrorCode.ERR_DataSectionStringLiteralHashCollision;
+        public override int ERR_EncUpdateRequiresEmittingExplicitInterfaceImplementationNotSupportedByTheRuntime => (int)ErrorCode.ERR_EncUpdateRequiresEmittingExplicitInterfaceImplementationNotSupportedByTheRuntime;
 
         // Generators:
         public override int WRN_GeneratorFailedDuringInitialization => (int)ErrorCode.WRN_GeneratorFailedDuringInitialization;

src/Compilers/CSharp/Test/Emit2/Emit/EditAndContinue/EditAndContinueTests.cs

@@ -21913,8 +21913,8 @@ class C
                 .Verify();
         }
 
-        [ConditionalFact(typeof(CoreClrOnly))]
-        public void PrivateImplDetails_CollectionExpressions_ReadOnlyListTypes()
+        [Fact]
+        public void PrivateImplDetails_CollectionExpressions_ReadOnlyListTypes_MethodImplSupported()
         {
             using var _ = new EditAndContinueTest(targetFramework: TargetFramework.Net80, verification: Verification.Skipped)
                 .AddBaseline(
@@ -22076,5 +22076,81 @@ class C
                     })
                 .Verify();
         }
+
+        [Fact]
+        [WorkItem("https://devdiv.visualstudio.com/DefaultCollection/DevDiv/_workitems/edit/2631743")]
+        public void PrivateImplDetails_CollectionExpressions_ReadOnlyListTypes_MethodImplNotSupported()
+        {
+            using var _ = new EditAndContinueTest(targetFramework: TargetFramework.NetFramework, verification: Verification.Skipped)
+                .AddBaseline(
+                    source: """
+                        using System.Collections.Generic;
+                        class C
+                        {
+                            static IEnumerable<int> F(int x, int y, IEnumerable<int> e) => [x, y];
+                        }
+                        """)
+
+                .AddGeneration(
+                    """
+                    using System.Collections.Generic;
+                    class C
+                    {
+                        static IEnumerable<int> F(int x, int y, IEnumerable<int> e) => [x, y, default];
+                    }
+                    """,
+                    edits:
+                    [
+                        Edit(SemanticEditKind.Update, symbolProvider: c => c.GetMember("C.F")),
+                    ],
+                    options: new EmitDifferenceOptions()
+                    {
+                        DisallowExplicitMethodImplementations = true
+                    },
+                    expectedErrors:
+                    [
+                        Diagnostic(ErrorCode.ERR_EncUpdateRequiresEmittingExplicitInterfaceImplementationNotSupportedByTheRuntime)
+                    ])
+                .Verify();
+        }
+
+        [Fact]
+        [WorkItem("https://devdiv.visualstudio.com/DefaultCollection/DevDiv/_workitems/edit/2631743")]
+        public void ExplicitInterfaceImplementation_MethodImplNotSupported()
+        {
+            using var _ = new EditAndContinueTest(targetFramework: TargetFramework.NetFramework, verification: Verification.Skipped)
+                .AddBaseline(
+                    source: """
+                    interface I 
+                    {
+                        void M();
+                    }
+                    """)
+
+                .AddGeneration(
+                    """
+                    interface I 
+                    {
+                        void M();
+                    }
+                    class C : I
+                    {
+                        void I.M() { }
+                    }
+                    """,
+                    edits:
+                    [
+                        Edit(SemanticEditKind.Insert, symbolProvider: c => c.GetMember("C")),
+                    ],
+                    options: new EmitDifferenceOptions()
+                    {
+                        DisallowExplicitMethodImplementations = true
+                    },
+                    expectedErrors:
+                    [
+                        Diagnostic(ErrorCode.ERR_EncUpdateRequiresEmittingExplicitInterfaceImplementationNotSupportedByTheRuntime)
+                    ])
+                .Verify();
+        }
     }
 }