Various refactorings to share more code with future generators (#67997)

src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/Marshalling/CustomTypeMarshallerDirection.cs

@@ -1,9 +1,13 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
-
+using System;
 using System.ComponentModel;
 
+#if MICROSOFT_INTEROP_SOURCEGENERATION
+namespace Microsoft.Interop
+#else
 namespace System.Runtime.InteropServices.Marshalling
+#endif
 {
     /// <summary>
     /// A direction of marshalling data into or out of the managed environment

src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/Marshalling/CustomTypeMarshallerFeatures.cs

@@ -1,7 +1,12 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
+using System;
 
+#if MICROSOFT_INTEROP_SOURCEGENERATION
+namespace Microsoft.Interop
+#else
 namespace System.Runtime.InteropServices.Marshalling
+#endif
 {
     /// <summary>
     /// Optional features supported by custom type marshallers.

src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/Marshalling/CustomTypeMarshallerKind.cs

@@ -1,7 +1,11 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+#if MICROSOFT_INTEROP_SOURCEGENERATION
+namespace Microsoft.Interop
+#else
 namespace System.Runtime.InteropServices.Marshalling
+#endif
 {
     /// <summary>
     /// The shape of a custom type marshaller for usage in source-generated interop scenarios.

src/libraries/System.Private.CoreLib/src/System/Runtime/InteropServices/StringMarshalling.cs

@@ -4,12 +4,16 @@
 //
 // Types in this file are used for generated p/invokes
 //
+#if MICROSOFT_INTEROP_SOURCEGENERATION
+namespace Microsoft.Interop
+#else
 namespace System.Runtime.InteropServices
+#endif
 {
     /// <summary>
     /// Specifies how strings should be marshalled for generated p/invokes
     /// </summary>
-#if SYSTEM_PRIVATE_CORELIB
+#if SYSTEM_PRIVATE_CORELIB || MICROSOFT_INTEROP_SOURCEGENERATION
     public
 #else
     internal

src/libraries/System.Runtime.InteropServices/gen/LibraryImportGenerator/Analyzers/CustomTypeMarshallerAnalyzer.cs

@@ -5,7 +5,6 @@
 using System.Collections.Immutable;
 using System.Linq;
 using System.Runtime.InteropServices;
-using System.Runtime.InteropServices.Marshalling;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Diagnostics;

src/libraries/System.Runtime.InteropServices/gen/LibraryImportGenerator/Analyzers/CustomTypeMarshallerFixer.cs

@@ -7,7 +7,6 @@
 using System.Composition;
 using System.Linq;
 using System.Runtime.InteropServices;
-using System.Runtime.InteropServices.Marshalling;
 using System.Text;
 using System.Threading;
 using System.Threading.Tasks;

src/libraries/System.Runtime.InteropServices/gen/LibraryImportGenerator/Comparers.cs

@@ -12,25 +12,10 @@ namespace Microsoft.Interop
 {
     internal static class Comparers
     {
-        /// <summary>
-        /// Comparer for the set of all of the generated stubs and diagnostics generated for each of them.
-        /// </summary>
-        public static readonly IEqualityComparer<ImmutableArray<(string, ImmutableArray<Diagnostic>)>> GeneratedSourceSet = new ImmutableArraySequenceEqualComparer<(string, ImmutableArray<Diagnostic>)>(new CustomValueTupleElementComparer<string, ImmutableArray<Diagnostic>>(EqualityComparer<string>.Default, new ImmutableArraySequenceEqualComparer<Diagnostic>(EqualityComparer<Diagnostic>.Default)));
-
-        /// <summary>
-        /// Comparer for an individual generated stub source as a string and the generated diagnostics for the stub.
-        /// </summary>
-        public static readonly IEqualityComparer<(string, ImmutableArray<Diagnostic>)> GeneratedSource = new CustomValueTupleElementComparer<string, ImmutableArray<Diagnostic>>(EqualityComparer<string>.Default, new ImmutableArraySequenceEqualComparer<Diagnostic>(EqualityComparer<Diagnostic>.Default));
-
         /// <summary>
         /// Comparer for an individual generated stub source as a syntax tree and the generated diagnostics for the stub.
         /// </summary>
         public static readonly IEqualityComparer<(MemberDeclarationSyntax Syntax, ImmutableArray<Diagnostic> Diagnostics)> GeneratedSyntax = new CustomValueTupleElementComparer<MemberDeclarationSyntax, ImmutableArray<Diagnostic>>(SyntaxEquivalentComparer.Instance, new ImmutableArraySequenceEqualComparer<Diagnostic>(EqualityComparer<Diagnostic>.Default));
-
-        /// <summary>
-        /// Comparer for the context used to generate a stub and the original user-provided syntax that triggered stub creation.
-        /// </summary>
-        public static readonly IEqualityComparer<(MethodDeclarationSyntax Syntax, LibraryImportGenerator.IncrementalStubGenerationContext StubContext)> CalculatedContextWithSyntax = new CustomValueTupleElementComparer<MethodDeclarationSyntax, LibraryImportGenerator.IncrementalStubGenerationContext>(SyntaxEquivalentComparer.Instance, EqualityComparer<LibraryImportGenerator.IncrementalStubGenerationContext>.Default);
     }
 
     /// <summary>
@@ -61,23 +46,6 @@ public int GetHashCode(ImmutableArray<T> obj)
         }
     }
 
-    internal sealed class SyntaxEquivalentComparer : IEqualityComparer<SyntaxNode>
-    {
-        public static readonly SyntaxEquivalentComparer Instance = new();
-
-        private SyntaxEquivalentComparer() { }
-
-        public bool Equals(SyntaxNode x, SyntaxNode y)
-        {
-            return x.IsEquivalentTo(y);
-        }
-
-        public int GetHashCode(SyntaxNode obj)
-        {
-            throw new UnreachableException();
-        }
-    }
-
     internal sealed class CustomValueTupleElementComparer<T, U> : IEqualityComparer<(T, U)>
     {
         private readonly IEqualityComparer<T> _item1Comparer;

src/libraries/System.Runtime.InteropServices/gen/LibraryImportGenerator/GeneratorDiagnostics.cs

@@ -210,11 +210,11 @@ public void ReportConfigurationNotSupported(
         /// <summary>
         /// Report diagnostic for marshalling of a parameter/return that is not supported
         /// </summary>
-        /// <param name="method">Method with the parameter/return</param>
+        /// <param name="diagnosticLocations">Method with the parameter/return</param>
         /// <param name="info">Type info for the parameter/return</param>
         /// <param name="notSupportedDetails">[Optional] Specific reason for lack of support</param>
         public void ReportMarshallingNotSupported(
-            MethodDeclarationSyntax method,
+            MethodSignatureDiagnosticLocations diagnosticLocations,
             TypePositionInfo info,
             string? notSupportedDetails,
             ImmutableDictionary<string, string> diagnosticProperties)
@@ -224,15 +224,14 @@ public void ReportMarshallingNotSupported(
 
             if (info.IsManagedReturnPosition)
             {
-                diagnosticLocation = Location.Create(method.SyntaxTree, method.Identifier.Span);
-                elementName = method.Identifier.ValueText;
+                diagnosticLocation = diagnosticLocations.FallbackLocation;
+                elementName = diagnosticLocations.MethodIdentifier;
             }
             else
             {
-                Debug.Assert(info.ManagedIndex <= method.ParameterList.Parameters.Count);
-                ParameterSyntax param = method.ParameterList.Parameters[info.ManagedIndex];
-                diagnosticLocation = Location.Create(param.SyntaxTree, param.Identifier.Span);
-                elementName = param.Identifier.ValueText;
+                Debug.Assert(info.ManagedIndex <= diagnosticLocations.ManagedParameterLocations.Length);
+                diagnosticLocation = diagnosticLocations.ManagedParameterLocations[info.ManagedIndex];
+                elementName = info.InstanceIdentifier;
             }
 
             if (!string.IsNullOrEmpty(notSupportedDetails))
@@ -322,12 +321,12 @@ public void ReportInvalidMarshallingAttributeInfo(
         /// <param name="method">Method with the configuration that cannot be forwarded</param>
         /// <param name="name">Configuration name</param>
         /// <param name="value">Configuration value</param>
-        public void ReportCannotForwardToDllImport(MethodDeclarationSyntax method, string name, string? value = null)
+        public void ReportCannotForwardToDllImport(MethodSignatureDiagnosticLocations method, string name, string? value = null)
         {
             _diagnostics.Add(
                 Diagnostic.Create(
                     CannotForwardToDllImport,
-                    Location.Create(method.SyntaxTree, method.Identifier.Span),
+                    method.FallbackLocation,
                     value is null ? name : $"{name}={value}"));
         }
 

src/libraries/System.Runtime.InteropServices/gen/LibraryImportGenerator/LibraryImportData.cs

@@ -7,32 +7,11 @@
 
 namespace Microsoft.Interop
 {
-    /// <summary>
-    /// Flags used to indicate members on LibraryImport attribute.
-    /// </summary>
-    [Flags]
-    public enum LibraryImportMember
-    {
-        None = 0,
-        EntryPoint = 1 << 0,
-        SetLastError = 1 << 1,
-        StringMarshalling = 1 << 2,
-        StringMarshallingCustomType = 1 << 3,
-        All = ~None
-    }
-
     /// <summary>
     /// LibraryImportAttribute data
     /// </summary>
-    internal sealed record LibraryImportData(string ModuleName)
+    internal sealed record LibraryImportData(string ModuleName) : InteropAttributeData
     {
-        /// <summary>
-        /// Value set by the user on the original declaration.
-        /// </summary>
-        public LibraryImportMember IsUserDefined { get; init; }
-        public string? EntryPoint { get; init; }
-        public bool SetLastError { get; init; }
-        public StringMarshalling StringMarshalling { get; init; }
-        public INamedTypeSymbol? StringMarshallingCustomType { get; init; }
+        public string EntryPoint { get; init; }
     }
 }