Refactor how diagnostics work in the interop generators

src/libraries/System.Runtime.InteropServices.JavaScript/gen/JSImportGenerator/DescriptorProvider.cs

@@ -0,0 +1,28 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using Microsoft.CodeAnalysis;
+
+namespace Microsoft.Interop.JavaScript
+{
+    internal sealed class DescriptorProvider : IDiagnosticDescriptorProvider
+    {
+        public DiagnosticDescriptor InvalidMarshallingAttributeInfo => GeneratorDiagnostics.MarshallingAttributeConfigurationNotSupported;
+
+        public DiagnosticDescriptor ConfigurationNotSupported => GeneratorDiagnostics.ConfigurationNotSupported;
+
+        public DiagnosticDescriptor ConfigurationValueNotSupported => GeneratorDiagnostics.ConfigurationValueNotSupported;
+
+        public DiagnosticDescriptor? GetDescriptor(GeneratorDiagnostic diagnostic)
+        {
+            return diagnostic switch
+            {
+                GeneratorDiagnostic.NotSupported { NotSupportedDetails: not null, TypePositionInfo.IsManagedReturnPosition: true } => GeneratorDiagnostics.ReturnTypeNotSupportedWithDetails,
+                GeneratorDiagnostic.NotSupported { NotSupportedDetails: not null, TypePositionInfo.IsManagedReturnPosition: false } => GeneratorDiagnostics.ParameterTypeNotSupportedWithDetails,
+                { IsFatal: false } => null, // The JSImport and JSExport generators don't report any non-fatal diagnostics.
+                { TypePositionInfo.IsManagedReturnPosition: true } => GeneratorDiagnostics.ReturnTypeNotSupported,
+                { TypePositionInfo.IsManagedReturnPosition: false } => GeneratorDiagnostics.ParameterTypeNotSupported,
+            };
+        }
+    }
+}

src/libraries/System.Runtime.InteropServices.JavaScript/gen/JSImportGenerator/GeneratorDiagnostics.cs

@@ -13,7 +13,7 @@ namespace Microsoft.Interop
     /// <summary>
     /// Class for reporting diagnostics in the library import generator
     /// </summary>
-    public class GeneratorDiagnostics : IGeneratorDiagnostics
+    public static class GeneratorDiagnostics
     {
         public class Ids
         {
@@ -28,145 +28,6 @@ public class Ids
         }
 
         private const string Category = "JSImportGenerator";
-        private readonly List<DiagnosticInfo> _diagnostics = new List<DiagnosticInfo>();
-
-        public IEnumerable<DiagnosticInfo> Diagnostics => _diagnostics;
-
-        public void ReportInvalidMarshallingAttributeInfo(
-            AttributeData attributeData,
-            string reasonResourceName,
-            params string[] reasonArgs)
-        {
-            _diagnostics.Add(
-                attributeData.CreateDiagnosticInfo(
-                    GeneratorDiagnostics.MarshallingAttributeConfigurationNotSupported,
-                    new LocalizableResourceString(reasonResourceName, SR.ResourceManager, typeof(FxResources.Microsoft.Interop.JavaScript.JSImportGenerator.SR), reasonArgs)));
-        }
-
-        /// <summary>
-        /// Report diagnostic for configuration that is not supported by the DLL import source generator
-        /// </summary>
-        /// <param name="attributeData">Attribute specifying the unsupported configuration</param>
-        /// <param name="configurationName">Name of the configuration</param>
-        /// <param name="unsupportedValue">[Optiona] Unsupported configuration value</param>
-        public void ReportConfigurationNotSupported(
-            AttributeData attributeData,
-            string configurationName,
-            string? unsupportedValue = null)
-        {
-            if (unsupportedValue == null)
-            {
-                _diagnostics.Add(
-                    attributeData.CreateDiagnosticInfo(
-                        GeneratorDiagnostics.ConfigurationNotSupported,
-                        configurationName));
-            }
-            else
-            {
-                _diagnostics.Add(
-                    attributeData.CreateDiagnosticInfo(
-                        GeneratorDiagnostics.ConfigurationValueNotSupported,
-                        unsupportedValue,
-                        configurationName));
-            }
-        }
-
-        /// <summary>
-        /// Report diagnostic for marshalling of a parameter/return that is not supported
-        /// </summary>
-        /// <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(
-            MethodSignatureDiagnosticLocations diagnosticLocations,
-            TypePositionInfo info,
-            string? notSupportedDetails,
-            ImmutableDictionary<string, string> diagnosticProperties)
-        {
-            Location diagnosticLocation = Location.None;
-            string elementName = string.Empty;
-
-            if (info.IsManagedReturnPosition)
-            {
-                diagnosticLocation = diagnosticLocations.FallbackLocation;
-                elementName = diagnosticLocations.MethodIdentifier;
-            }
-            else
-            {
-                Debug.Assert(info.ManagedIndex <= diagnosticLocations.ManagedParameterLocations.Length);
-                diagnosticLocation = diagnosticLocations.ManagedParameterLocations[info.ManagedIndex];
-                elementName = info.InstanceIdentifier;
-            }
-
-            if (!string.IsNullOrEmpty(notSupportedDetails))
-            {
-                // Report the specific not-supported reason.
-                if (info.IsManagedReturnPosition)
-                {
-                    _diagnostics.Add(
-                        diagnosticLocation.CreateDiagnosticInfo(
-                            GeneratorDiagnostics.ReturnTypeNotSupportedWithDetails,
-                            diagnosticProperties,
-                            notSupportedDetails!,
-                            elementName));
-                }
-                else
-                {
-                    _diagnostics.Add(
-                        diagnosticLocation.CreateDiagnosticInfo(
-                            GeneratorDiagnostics.ParameterTypeNotSupportedWithDetails,
-                            diagnosticProperties,
-                            notSupportedDetails!,
-                            elementName));
-                }
-            }
-            else if (info.MarshallingAttributeInfo is MarshalAsInfo)
-            {
-                // Report that the specified marshalling configuration is not supported.
-                // We don't forward marshalling attributes, so this is reported differently
-                // than when there is no attribute and the type itself is not supported.
-                if (info.IsManagedReturnPosition)
-                {
-                    _diagnostics.Add(
-                        diagnosticLocation.CreateDiagnosticInfo(
-                            GeneratorDiagnostics.ReturnConfigurationNotSupported,
-                            diagnosticProperties,
-                            nameof(System.Runtime.InteropServices.MarshalAsAttribute),
-                            elementName));
-                }
-                else
-                {
-                    _diagnostics.Add(
-                        diagnosticLocation.CreateDiagnosticInfo(
-                            GeneratorDiagnostics.ParameterConfigurationNotSupported,
-                            diagnosticProperties,
-                            nameof(System.Runtime.InteropServices.MarshalAsAttribute),
-                            elementName));
-                }
-            }
-            else
-            {
-                // Report that the type is not supported
-                if (info.IsManagedReturnPosition)
-                {
-                    _diagnostics.Add(
-                        diagnosticLocation.CreateDiagnosticInfo(
-                            GeneratorDiagnostics.ReturnTypeNotSupported,
-                            diagnosticProperties,
-                            info.ManagedType.DiagnosticFormattedName,
-                            elementName));
-                }
-                else
-                {
-                    _diagnostics.Add(
-                        diagnosticLocation.CreateDiagnosticInfo(
-                            GeneratorDiagnostics.ParameterTypeNotSupported,
-                            diagnosticProperties,
-                            info.ManagedType.DiagnosticFormattedName,
-                            elementName));
-                }
-            }
-        }
 
         public static readonly DiagnosticDescriptor ConfigurationNotSupported =
             new DiagnosticDescriptor(
@@ -209,14 +70,14 @@ public void ReportMarshallingNotSupported(
                 description: GetResourceString(nameof(SR.TypeNotSupportedDescription)));
 
         public static readonly DiagnosticDescriptor ParameterTypeNotSupported =
-                    new DiagnosticDescriptor(
-                        Ids.TypeNotSupported,
-                        GetResourceString(nameof(SR.TypeNotSupportedTitle)),
-                        GetResourceString(nameof(SR.TypeNotSupportedMessageParameter)),
-                        Category,
-                        DiagnosticSeverity.Error,
-                        isEnabledByDefault: true,
-                        description: GetResourceString(nameof(SR.TypeNotSupportedDescription)));
+            new DiagnosticDescriptor(
+                Ids.TypeNotSupported,
+                GetResourceString(nameof(SR.TypeNotSupportedTitle)),
+                GetResourceString(nameof(SR.TypeNotSupportedMessageParameter)),
+                Category,
+                DiagnosticSeverity.Error,
+                isEnabledByDefault: true,
+                description: GetResourceString(nameof(SR.TypeNotSupportedDescription)));
 
         public static readonly DiagnosticDescriptor ReturnTypeNotSupported =
             new DiagnosticDescriptor(

src/libraries/System.Runtime.InteropServices.JavaScript/gen/JSImportGenerator/JSExportCodeGenerator.cs

@@ -25,20 +25,16 @@ public JSExportCodeGenerator(
             ImmutableArray<TypePositionInfo> argTypes,
             JSExportData attributeData,
             JSSignatureContext signatureContext,
-            Action<TypePositionInfo, MarshallingNotSupportedException> marshallingNotSupportedCallback,
+            GeneratorDiagnosticsBag diagnosticsBag,
             IMarshallingGeneratorFactory generatorFactory)
         {
-            Action<TypePositionInfo, string> extendedInvariantViolationsCallback = (info, details) =>
-                marshallingNotSupportedCallback(info, new MarshallingNotSupportedException(info, _context) { NotSupportedDetails = details });
             _signatureContext = signatureContext;
             NativeToManagedStubCodeContext innerContext = new NativeToManagedStubCodeContext(targetFramework, targetFrameworkVersion, ReturnIdentifier, ReturnIdentifier);
             _context = new JSExportCodeContext(attributeData, innerContext);
 
             _marshallers = BoundGenerators.Create(argTypes, generatorFactory, _context, new EmptyJSGenerator(), out var bindingFailures);
-            foreach (var failure in bindingFailures)
-            {
-                marshallingNotSupportedCallback(failure.Info, failure.Exception);
-            }
+
+            diagnosticsBag.ReportGeneratorDiagnostics(bindingFailures);
 
             if (_marshallers.ManagedReturnMarshaller.Generator.UsesNativeIdentifier(_marshallers.ManagedReturnMarshaller.TypeInfo, null))
             {
@@ -53,7 +49,7 @@ public JSExportCodeGenerator(
                 BoundGenerator spanArg = _marshallers.SignatureMarshallers.FirstOrDefault(m => m.TypeInfo.MarshallingAttributeInfo is JSMarshallingInfo(_, JSSpanTypeInfo));
                 if (spanArg != default)
                 {
-                    marshallingNotSupportedCallback(spanArg.TypeInfo, new MarshallingNotSupportedException(spanArg.TypeInfo, _context)
+                    diagnosticsBag.ReportGeneratorDiagnostic(new GeneratorDiagnostic.NotSupported(spanArg.TypeInfo, _context)
                     {
                         NotSupportedDetails = SR.SpanAndTaskNotSupported
                     });

src/libraries/System.Runtime.InteropServices.JavaScript/gen/JSImportGenerator/JSExportGenerator.cs

@@ -189,7 +189,8 @@ private static IncrementalStubGenerationContext CalculateStubInformation(
 
             Debug.Assert(jsExportAttr is not null);
 
-            var generatorDiagnostics = new GeneratorDiagnostics();
+            var locations = new MethodSignatureDiagnosticLocations(originalSyntax);
+            var generatorDiagnostics = new GeneratorDiagnosticsBag(new DescriptorProvider(), locations, SR.ResourceManager, typeof(FxResources.Microsoft.Interop.JavaScript.JSImportGenerator.SR));
 
             // Process the JSExport attribute
             JSExportData? jsExportData = ProcessJSExportAttribute(jsExportAttr!);
@@ -211,7 +212,7 @@ private static IncrementalStubGenerationContext CalculateStubInformation(
                 signatureContext,
                 containingTypeContext,
                 methodSyntaxTemplate,
-                new MethodSignatureDiagnosticLocations(originalSyntax),
+                locations,
                 jsExportData,
                 CreateGeneratorFactory(environment, options),
                 new SequenceEqualImmutableArray<DiagnosticInfo>(generatorDiagnostics.Diagnostics.ToImmutableArray()));
@@ -289,20 +290,17 @@ private static NamespaceDeclarationSyntax GenerateRegSource(
         private static (MemberDeclarationSyntax, StatementSyntax, AttributeListSyntax, ImmutableArray<DiagnosticInfo>) GenerateSource(
             IncrementalStubGenerationContext incrementalContext)
         {
-            var diagnostics = new GeneratorDiagnostics();
+            var diagnostics = new GeneratorDiagnosticsBag(new DescriptorProvider(), incrementalContext.DiagnosticLocation, SR.ResourceManager, typeof(FxResources.Microsoft.Interop.JavaScript.JSImportGenerator.SR));
 
             // Generate stub code
             var stubGenerator = new JSExportCodeGenerator(
-            incrementalContext.GeneratorFactoryKey.Key.TargetFramework,
-            incrementalContext.GeneratorFactoryKey.Key.TargetFrameworkVersion,
-            incrementalContext.SignatureContext.SignatureContext.ElementTypeInformation,
-            incrementalContext.JSExportData,
-            incrementalContext.SignatureContext,
-            (elementInfo, ex) =>
-            {
-                diagnostics.ReportMarshallingNotSupported(incrementalContext.DiagnosticLocation, elementInfo, ex.NotSupportedDetails, ex.DiagnosticProperties ?? ImmutableDictionary<string, string>.Empty);
-            },
-            incrementalContext.GeneratorFactoryKey.GeneratorFactory);
+                incrementalContext.GeneratorFactoryKey.Key.TargetFramework,
+                incrementalContext.GeneratorFactoryKey.Key.TargetFrameworkVersion,
+                incrementalContext.SignatureContext.SignatureContext.ElementTypeInformation,
+                incrementalContext.JSExportData,
+                incrementalContext.SignatureContext,
+                diagnostics,
+                incrementalContext.GeneratorFactoryKey.GeneratorFactory);
 
             var wrapperName = "__Wrapper_" + incrementalContext.StubMethodSyntaxTemplate.Identifier + "_" + incrementalContext.SignatureContext.TypesHash;