Fix for some minor code issues (#29)

ChrisPulman · web-flow · commit 9c179669620c · 2024-08-17T04:17:16.000+01:00
Fix some minor code issues
diff --git a/src/Directory.Packages.props b/src/Directory.Packages.props
@@ -2,9 +2,9 @@
   <PropertyGroup>
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
     <CentralPackageTransitivePinningEnabled>true</CentralPackageTransitivePinningEnabled>
+    <CodeAnalysisVersion>4.0.1</CodeAnalysisVersion>
   </PropertyGroup>
   <ItemGroup>
-    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="4.0.1" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
     <PackageVersion Include="xunit" Version="2.9.0" />
     <PackageVersion Include="xunit.runner.console" Version="2.9.0" />
@@ -23,7 +23,8 @@
     <PackageVersion Include="Microsoft.Maui.Controls" Version="$(MauiVersion)" />
     <PackageVersion Include="Microsoft.Maui.Controls.Compatibility" Version="$(MauiVersion)" />
     <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.0.1" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="$(CodeAnalysisVersion)" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp.Workspaces" Version="$(CodeAnalysisVersion)" />
     <PackageVersion Include="PolySharp" Version="1.14.1" />
   </ItemGroup>
-</Project>
+</Project>
diff --git a/src/ReactiveUI.SourceGenerators.Execute/ReactiveUI.SourceGenerators.Execute.csproj b/src/ReactiveUI.SourceGenerators.Execute/ReactiveUI.SourceGenerators.Execute.csproj
@@ -8,7 +8,7 @@
     <UseWindowsForms>true</UseWindowsForms>
     <Nullable>enable</Nullable>
     <IsPackable>false</IsPackable>
-    <LangVersion>latest</LangVersion>
+    <LangVersion>12.0</LangVersion>
     <PackageDescription>A MVVM framework that integrates with the Reactive Extensions for .NET to create elegant, testable User Interfaces that run on any mobile or desktop platform. This is the Source Generators package for ReactiveUI</PackageDescription>
   </PropertyGroup>
 
diff --git a/src/ReactiveUI.SourceGenerators/AnalyzerReleases.Shipped.md b/src/ReactiveUI.SourceGenerators/AnalyzerReleases.Shipped.md
@@ -14,7 +14,7 @@ RXUISG0004 | ReactiveUI.SourceGenerators.ReactiveCommandGenerator | Error | See
 RXUISG0005 | ReactiveUI.SourceGenerators.ReactiveCommandGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0005
 RXUISG0006 | ReactiveUI.SourceGenerators.ReactiveCommandGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0006
 RXUISG0007 | ReactiveUI.SourceGenerators.ReactiveCommandGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0007
-RXUISG0008 | ReactiveUI.SourceGenerators.ReactiveCommandGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0008
+RXUISG0008 | ReactiveUI.SourceGenerators.AsyncVoidReturningReactiveCommandMethodAnalyzer | Error | See https://www.reactiveui.net/errors/RXUISG0008
 RXUISG0009 | ReactiveUI.SourceGenerators.ReactiveGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0009
 RXUISG0010 | ReactiveUI.SourceGenerators.ReactiveGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0010
 RXUISG0011 | ReactiveUI.SourceGenerators.ReactiveGenerator | Error | See https://www.reactiveui.net/errors/RXUISG0011
diff --git a/src/ReactiveUI.SourceGenerators/Diagnostics/Analyzers/UnsupportedCSharpLanguageVersionAnalyzer.cs b/src/ReactiveUI.SourceGenerators/Diagnostics/Analyzers/UnsupportedCSharpLanguageVersionAnalyzer.cs
@@ -33,7 +33,7 @@ public sealed class UnsupportedCSharpLanguageVersionAnalyzer : DiagnosticAnalyze
     });
 
     /// <inheritdoc/>
-    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; } = ImmutableArray.Create(UnsupportedCSharpLanguageVersionError);
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(UnsupportedCSharpLanguageVersionError);
 
     /// <inheritdoc/>
     public override void Initialize(AnalysisContext context)
@@ -51,13 +51,13 @@ public override void Initialize(AnalysisContext context)
         context.RegisterCompilationStartAction(static context =>
         {
             // Check that the language version is not high enough, otherwise no diagnostic should ever be produced
-            if (context.Compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp8))
+            if (context.Compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp9))
             {
                 return;
             }
 
             // Try to get all necessary type symbols
-            if (!context.Compilation.TryBuildNamedTypeSymbolMap(GeneratorAttributeNamesToFullyQualifiedNamesMap, out ImmutableDictionary<string, INamedTypeSymbol>? typeSymbols))
+            if (!context.Compilation.TryBuildNamedTypeSymbolMap(GeneratorAttributeNamesToFullyQualifiedNamesMap, out var typeSymbols))
             {
                 return;
             }
@@ -76,7 +76,7 @@ public override void Initialize(AnalysisContext context)
                     // Go over each attribute on the target symbol, and check if the attribute type name is a candidate.
                     // If it is, double check by actually resolving the symbol from the mapping and comparing against it.
                     if (attribute.AttributeClass is { Name: string attributeName } attributeClass &&
-                        typeSymbols.TryGetValue(attributeName, out INamedTypeSymbol? attributeSymbol) &&
+                        typeSymbols.TryGetValue(attributeName, out var attributeSymbol) &&
                         SymbolEqualityComparer.Default.Equals(attributeClass, attributeSymbol))
                     {
                         context.ReportDiagnostic(Diagnostic.Create(UnsupportedCSharpLanguageVersionError, context.Symbol.Locations.FirstOrDefault()));
diff --git a/src/ReactiveUI.SourceGenerators/Diagnostics/DiagnosticDescriptors.cs b/src/ReactiveUI.SourceGenerators/Diagnostics/DiagnosticDescriptors.cs
@@ -21,27 +21,27 @@ internal static class DiagnosticDescriptors
     public static readonly DiagnosticDescriptor UnsupportedCSharpLanguageVersionError = new DiagnosticDescriptor(
         id: "RXUISG0001",
         title: "Unsupported C# language version",
-        messageFormat: "The source generator features from ReactiveUI require consuming projects to set the C# language version to at least C# 8.0",
+        messageFormat: "The source generator features from ReactiveUI require consuming projects to set the C# language version to at least C# 9.0",
         category: typeof(UnsupportedCSharpLanguageVersionAnalyzer).FullName,
         defaultSeverity: DiagnosticSeverity.Error,
         isEnabledByDefault: true,
-        description: "The source generator features from ReactiveUI require consuming projects to set the C# language version to at least C# 8.0. Make sure to add <LangVersion>8.0</LangVersion> (or above) to your .csproj file.",
+        description: "The source generator features from ReactiveUI require consuming projects to set the C# language version to at least C# 9.0. Make sure to add <LangVersion>9.0</LangVersion> (or above) to your .csproj file.",
         helpLinkUri: "https://www.reactiveui.net/errors/RXUISG0001");
 
     /// <summary>
     /// Gets a <see cref="DiagnosticDescriptor"/> indicating when an annotated method to generate a command for has an invalid signature.
     /// <para>
-    /// Format: <c>"The method {0}.{1} cannot be used to generate a command property, as its signature isn't compatible with any of the existing relay command types"</c>.
+    /// Format: <c>"The method {0}.{1} cannot be used to generate a command property, as its signature isn't compatible with any of the existing reactive command types"</c>.
     /// </para>
     /// </summary>
     public static readonly DiagnosticDescriptor InvalidReactiveCommandMethodSignatureError = new DiagnosticDescriptor(
         id: "RXUISG0002",
         title: "Invalid ReactiveCommand method signature",
-        messageFormat: "The method {0}.{1} cannot be used to generate a command property, as its signature isn't compatible with any of the existing relay command types",
+        messageFormat: "The method {0}.{1} cannot be used to generate a command property, as its signature isn't compatible with any of the existing reactive command types",
         category: typeof(ReactiveCommandGenerator).FullName,
         defaultSeverity: DiagnosticSeverity.Error,
         isEnabledByDefault: true,
-        description: "Cannot apply [ReactiveCommand] to methods with a signature that doesn't match any of the existing relay command types.",
+        description: "Cannot apply [ReactiveCommand] to methods with a signature that doesn't match any of the existing reactive command types.",
         helpLinkUri: "https://www.reactiveui.net/errors/RXUISG0002");
 
     /// <summary>
@@ -134,7 +134,7 @@ internal static class DiagnosticDescriptors
         id: "RXUISG0008",
         title: "Async void returning method annotated with ReactiveCommand",
         messageFormat: "The method {0} annotated with [ReactiveCommand] is async void (make sure to return a Task type instead)",
-        category: typeof(ReactiveCommandGenerator).FullName,
+        category: typeof(AsyncVoidReturningReactiveCommandMethodAnalyzer).FullName,
         defaultSeverity: DiagnosticSeverity.Error,
         isEnabledByDefault: true,
         description: "All asynchronous methods annotated with [ReactiveCommand] should return a Task type, to benefit from the additional support provided by ReactiveCommand.FromTask.",
diff --git a/src/ReactiveUI.SourceGenerators/Diagnostics/Suppressions/ObservableAsPropertyAttributeWithFieldNeverReadDiagnosticSuppressor.cs b/src/ReactiveUI.SourceGenerators/Diagnostics/Suppressions/ObservableAsPropertyAttributeWithFieldNeverReadDiagnosticSuppressor.cs
@@ -16,7 +16,7 @@ namespace ReactiveUI.SourceGenerators.Diagnostics.Suppressions
     /// <summary>
     /// ObservableAsProperty Attribute With Field Never Read Diagnostic Suppressor.
     /// </summary>
-    /// <seealso cref="Microsoft.CodeAnalysis.Diagnostics.DiagnosticSuppressor" />
+    /// <seealso cref="DiagnosticSuppressor" />
     [DiagnosticAnalyzer(LanguageNames.CSharp)]
     public sealed class ObservableAsPropertyAttributeWithFieldNeverReadDiagnosticSuppressor : DiagnosticSuppressor
     {
@@ -38,7 +38,7 @@ public override void ReportSuppressions(SuppressionAnalysisContext context)
                     // Get the method symbol from the first variable declaration
                     ISymbol? declaredSymbol = semanticModel.GetDeclaredSymbol(methodDeclaration, context.CancellationToken);
 
-                    // Check if the method is using [RelayCommand], in which case we should suppress the warning
+                    // Check if the method is using [ObservableAsProperty], in which case we should suppress the warning
                     if (declaredSymbol is IMethodSymbol methodSymbol &&
                         semanticModel.Compilation.GetTypeByMetadataName("ReactiveUI.SourceGenerators.ObservableAsPropertyAttribute") is INamedTypeSymbol reactiveCommandSymbol &&
                         methodSymbol.HasAttributeWithType(reactiveCommandSymbol))
diff --git a/src/ReactiveUI.SourceGenerators/Extensions/SourceProductionContextExtensions.cs b/src/ReactiveUI.SourceGenerators/Extensions/SourceProductionContextExtensions.cs
@@ -20,7 +20,7 @@ internal static class SourceProductionContextExtensions
     /// <param name="context">The input <see cref="SourceProductionContext"/> instance to use.</param>
     /// <param name="name">The name of the source file to add.</param>
     /// <param name="compilationUnit">The <see cref="CompilationUnitSyntax"/> instance representing the syntax tree to add.</param>
-    public static void AddSource(this SourceProductionContext context, string name, CompilationUnitSyntax compilationUnit)
+    public static void AddSource(this in SourceProductionContext context, string name, CompilationUnitSyntax compilationUnit)
     {
 #if !ROSLYN_4_3_1_OR_GREATER
         // We're fine with the extra allocation in the few cases where adjusting the filename is necessary.
diff --git a/src/ReactiveUI.SourceGenerators/Extensions/SyntaxTokenExtensions.cs b/src/ReactiveUI.SourceGenerators/Extensions/SyntaxTokenExtensions.cs
@@ -18,5 +18,5 @@ internal static class SyntaxTokenExtensions
     /// </summary>
     /// <param name="syntaxToken">The input <see cref="SyntaxToken"/> value.</param>
     /// <param name="syntaxKind">The resulting <see cref="SyntaxKind"/> value for <paramref name="syntaxToken"/>.</param>
-    public static void Deconstruct(this SyntaxToken syntaxToken, out SyntaxKind syntaxKind) => syntaxKind = syntaxToken.Kind();
+    public static void Deconstruct(this in SyntaxToken syntaxToken, out SyntaxKind syntaxKind) => syntaxKind = syntaxToken.Kind();
 }
diff --git a/src/ReactiveUI.SourceGenerators/Helpers/EquatableArray{T}.cs b/src/ReactiveUI.SourceGenerators/Helpers/EquatableArray{T}.cs
@@ -89,7 +89,9 @@ public ref readonly T this[int index]
     /// </summary>
     /// <param name="array">The array.</param>
     /// <returns>A bool.</returns>
+#pragma warning disable RCS1168 // Parameter name differs from base name
     public bool Equals(EquatableArray<T> array) => AsSpan().SequenceEqual(array.AsSpan());
+#pragma warning restore RCS1168 // Parameter name differs from base name
 
     /// <summary>
     /// Equalses the specified object.
@@ -153,9 +155,7 @@ public override int GetHashCode()
 /// Extensions for <see cref="EquatableArray{T}"/>.
 /// </summary>
 #pragma warning disable SA1402 // File may only contain a single type
-#pragma warning disable SA1649 // File name should match first type name
 internal static class EquatableArray
-#pragma warning restore SA1649 // File name should match first type name
 #pragma warning restore SA1402 // File may only contain a single type
 {
     /// <summary>
diff --git a/src/ReactiveUI.SourceGenerators/Helpers/HashCode.cs b/src/ReactiveUI.SourceGenerators/Helpers/HashCode.cs
@@ -46,7 +46,7 @@ internal struct HashCode
     /// Gets the resulting hashcode from the current instance.
     /// </summary>
     /// <returns>The resulting hashcode from the current instance.</returns>
-    public int ToHashCode()
+    public readonly int ToHashCode()
     {
         var length = _length;
         var position = length % 4;
@@ -77,12 +77,12 @@ public int ToHashCode()
     /// <inheritdoc/>
     [Obsolete("HashCode is a mutable struct and should not be compared with other HashCodes. Use ToHashCode to retrieve the computed hash code.", error: true)]
     [EditorBrowsable(EditorBrowsableState.Never)]
-    public override int GetHashCode() => throw new NotSupportedException();
+    public override readonly int GetHashCode() => throw new NotSupportedException();
 
     /// <inheritdoc/>
     [Obsolete("HashCode is a mutable struct and should not be compared with other HashCodes.", error: true)]
     [EditorBrowsable(EditorBrowsableState.Never)]
-    public override bool Equals(object? obj) => throw new NotSupportedException();
+    public override readonly bool Equals(object? obj) => throw new NotSupportedException();
 
     /// <summary>
     /// Rotates the specified value left by the specified number of bits.
diff --git a/src/ReactiveUI.SourceGenerators/Helpers/ImmutableArrayBuilder{T}.cs b/src/ReactiveUI.SourceGenerators/Helpers/ImmutableArrayBuilder{T}.cs
@@ -65,7 +65,7 @@ public readonly int Count
     /// Adds the specified items to the end of the array.
     /// </summary>
     /// <param name="items">The items to add at the end of the array.</param>
-    public readonly void AddRange(scoped ReadOnlySpan<T> items) => _writer!.AddRange(items);
+    public readonly void AddRange(scoped in ReadOnlySpan<T> items) => _writer!.AddRange(items);
 
     /// <inheritdoc cref="ImmutableArray{T}.Builder.ToImmutable"/>
     public readonly ImmutableArray<T> ToImmutable()
@@ -110,54 +110,49 @@ private sealed class Writer : ICollection<T>, IDisposable
         /// </summary>
         private T?[]? _array;
 
-        /// <summary>
-        /// The starting offset within <see cref="_array"/>.
-        /// </summary>
-        private int _index;
-
         /// <summary>
         /// Initializes a new instance of the <see cref="Writer"/> class.
         /// Creates a new <see cref="Writer"/> instance with the specified parameters.
         /// </summary>
         public Writer()
         {
             _array = ArrayPool<T?>.Shared.Rent(typeof(T) == typeof(char) ? 1024 : 8);
-            _index = 0;
+            Count = 0;
         }
 
         /// <inheritdoc cref="ImmutableArrayBuilder{T}.Count"/>
         public int Count
         {
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
-            get => _index;
+            get; private set;
         }
 
         /// <inheritdoc cref="ImmutableArrayBuilder{T}.WrittenSpan"/>
         public ReadOnlySpan<T> WrittenSpan
         {
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
-            get => new(_array!, 0, _index);
+            get => new(_array!, 0, Count);
         }
 
         /// <inheritdoc/>
         bool ICollection<T>.IsReadOnly => true;
 
         /// <inheritdoc cref="ImmutableArrayBuilder{T}.Add"/>
-        public void Add(T value)
+        public void Add(T item)
         {
             EnsureCapacity(1);
 
-            _array![_index++] = value;
+            _array![Count++] = item;
         }
 
         /// <inheritdoc cref="ImmutableArrayBuilder{T}.AddRange"/>
         public void AddRange(in ReadOnlySpan<T> items)
         {
             EnsureCapacity(items.Length);
 
-            items.CopyTo(_array.AsSpan(_index)!);
+            items.CopyTo(_array.AsSpan(Count)!);
 
-            _index += items.Length;
+            Count += items.Length;
         }
 
         /// <inheritdoc/>
@@ -180,13 +175,13 @@ public void Dispose()
         bool ICollection<T>.Contains(T item) => throw new NotSupportedException();
 
         /// <inheritdoc/>
-        void ICollection<T>.CopyTo(T[] array, int arrayIndex) => Array.Copy(_array!, 0, array, arrayIndex, _index);
+        void ICollection<T>.CopyTo(T[] array, int arrayIndex) => Array.Copy(_array!, 0, array, arrayIndex, Count);
 
         /// <inheritdoc/>
         IEnumerator<T> IEnumerable<T>.GetEnumerator()
         {
             var array = _array!;
-            var length = _index;
+            var length = Count;
 
             for (var i = 0; i < length; i++)
             {
@@ -207,7 +202,7 @@ IEnumerator<T> IEnumerable<T>.GetEnumerator()
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         private void EnsureCapacity(int requestedSize)
         {
-            if (requestedSize > _array!.Length - _index)
+            if (requestedSize > _array!.Length - Count)
             {
                 ResizeBuffer(requestedSize);
             }
@@ -220,12 +215,12 @@ private void EnsureCapacity(int requestedSize)
         [MethodImpl(MethodImplOptions.NoInlining)]
         private void ResizeBuffer(int sizeHint)
         {
-            var minimumSize = _index + sizeHint;
+            var minimumSize = Count + sizeHint;
 
             var oldArray = _array!;
             var newArray = ArrayPool<T?>.Shared.Rent(minimumSize);
 
-            Array.Copy(oldArray, newArray, _index);
+            Array.Copy(oldArray, newArray, Count);
 
             _array = newArray;
 
diff --git a/src/ReactiveUI.SourceGenerators/IViewFor/IViewForGenerator.Execute.cs b/src/ReactiveUI.SourceGenerators/IViewFor/IViewForGenerator.Execute.cs
@@ -16,7 +16,7 @@ namespace ReactiveUI.SourceGenerators;
 /// <summary>
 /// IViewForGenerator.
 /// </summary>
-/// <seealso cref="Microsoft.CodeAnalysis.IIncrementalGenerator" />
+/// <seealso cref="IIncrementalGenerator" />
 public partial class IViewForGenerator
 {
     internal static class Execute
diff --git a/src/ReactiveUI.SourceGenerators/Models/HierarchyInfo.Syntax.cs b/src/ReactiveUI.SourceGenerators/Models/HierarchyInfo.Syntax.cs
@@ -36,7 +36,7 @@ public CompilationUnitSyntax GetCompilationUnit(
         var typeDeclarationSyntax =
             Hierarchy[0].GetSyntax()
             .AddModifiers(Token(TriviaList(Comment("/// <inheritdoc/>")), SyntaxKind.PartialKeyword, TriviaList()))
-            .AddMembers(memberDeclarations.ToArray());
+            .AddMembers([.. memberDeclarations]);
 
         // Add the base list, if present
         if (baseList is not null)
diff --git a/src/ReactiveUI.SourceGenerators/Polyfills/SyntaxValueProviderExtensions.cs b/src/ReactiveUI.SourceGenerators/Polyfills/SyntaxValueProviderExtensions.cs
@@ -67,7 +67,7 @@ public static IncrementalValuesProvider<T> ForAttributeWithMetadataName<T>(
                         return null;
                     }
 
-                    if (!context.SemanticModel.Compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp8))
+                    if (!context.SemanticModel.Compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp9))
                     {
                         return null;
                     }
@@ -111,7 +111,7 @@ public static IncrementalValuesProvider<T> ForAllAttributes<T>(
                         return null;
                     }
 
-                    if (!context.SemanticModel.Compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp8))
+                    if (!context.SemanticModel.Compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp9))
                     {
                         return null;
                     }
diff --git a/src/ReactiveUI.SourceGenerators/ReactiveUI.SourceGenerators.csproj b/src/ReactiveUI.SourceGenerators/ReactiveUI.SourceGenerators.csproj
@@ -33,13 +33,13 @@
 
   <!-- Include PolySharp to generate polyfills for all projects (on their .NET Standard 2.x targets) -->
   <ItemGroup>
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" />
     <PackageReference Include="PolySharp">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>build; analyzers</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" PrivateAssets="all" />
-    <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" PrivateAssets="all" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" />
+    <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" />
   </ItemGroup>
 
   <!-- This ensures the library will be packaged as a source generator when we use `dotnet pack` -->

Original file line number	Diff line number	Diff line change
`@@ -33,7 +33,7 @@ public sealed class UnsupportedCSharpLanguageVersionAnalyzer : DiagnosticAnalyze`
`33`	`33`	`});`
`34`	`34`
`35`	`35`	`/// <inheritdoc/>`
`36`		`- public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; } = ImmutableArray.Create(UnsupportedCSharpLanguageVersionError);`
	`36`	`+ public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => ImmutableArray.Create(UnsupportedCSharpLanguageVersionError);`
`37`	`37`
`38`	`38`	`/// <inheritdoc/>`
`39`	`39`	`public override void Initialize(AnalysisContext context)`
`@@ -51,13 +51,13 @@ public override void Initialize(AnalysisContext context)`
`51`	`51`	`context.RegisterCompilationStartAction(static context =>`
`52`	`52`	`{`
`53`	`53`	`// Check that the language version is not high enough, otherwise no diagnostic should ever be produced`
`54`		`- if (context.Compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp8))`
	`54`	`+ if (context.Compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp9))`
`55`	`55`	`{`
`56`	`56`	`return;`
`57`	`57`	`}`
`58`	`58`
`59`	`59`	`// Try to get all necessary type symbols`
`60`		`- if (!context.Compilation.TryBuildNamedTypeSymbolMap(GeneratorAttributeNamesToFullyQualifiedNamesMap, out ImmutableDictionary<string, INamedTypeSymbol>? typeSymbols))`
	`60`	`+ if (!context.Compilation.TryBuildNamedTypeSymbolMap(GeneratorAttributeNamesToFullyQualifiedNamesMap, out var typeSymbols))`
`61`	`61`	`{`
`62`	`62`	`return;`
`63`	`63`	`}`
`@@ -76,7 +76,7 @@ public override void Initialize(AnalysisContext context)`
`76`	`76`	`// Go over each attribute on the target symbol, and check if the attribute type name is a candidate.`
`77`	`77`	`// If it is, double check by actually resolving the symbol from the mapping and comparing against it.`
`78`	`78`	`if (attribute.AttributeClass is { Name: string attributeName } attributeClass &&`
`79`		`- typeSymbols.TryGetValue(attributeName, out INamedTypeSymbol? attributeSymbol) &&`
	`79`	`+ typeSymbols.TryGetValue(attributeName, out var attributeSymbol) &&`
`80`	`80`	`SymbolEqualityComparer.Default.Equals(attributeClass, attributeSymbol))`
`81`	`81`	`{`
`82`	`82`	`context.ReportDiagnostic(Diagnostic.Create(UnsupportedCSharpLanguageVersionError, context.Symbol.Locations.FirstOrDefault()));`
Original file line number	Diff line number	Diff line change
`@@ -20,7 +20,7 @@ internal static class SourceProductionContextExtensions`
`20`	`20`	`/// <param name="context">The input <see cref="SourceProductionContext"/> instance to use.</param>`
`21`	`21`	`/// <param name="name">The name of the source file to add.</param>`
`22`	`22`	`/// <param name="compilationUnit">The <see cref="CompilationUnitSyntax"/> instance representing the syntax tree to add.</param>`
`23`		`- public static void AddSource(this SourceProductionContext context, string name, CompilationUnitSyntax compilationUnit)`
	`23`	`+ public static void AddSource(this in SourceProductionContext context, string name, CompilationUnitSyntax compilationUnit)`
`24`	`24`	`{`
`25`	`25`	`#if !ROSLYN_4_3_1_OR_GREATER`
`26`	`26`	`// We're fine with the extra allocation in the few cases where adjusting the filename is necessary.`
Original file line number	Diff line number	Diff line change
`@@ -18,5 +18,5 @@ internal static class SyntaxTokenExtensions`
`18`	`18`	`/// </summary>`
`19`	`19`	`/// <param name="syntaxToken">The input <see cref="SyntaxToken"/> value.</param>`
`20`	`20`	`/// <param name="syntaxKind">The resulting <see cref="SyntaxKind"/> value for <paramref name="syntaxToken"/>.</param>`
`21`		`- public static void Deconstruct(this SyntaxToken syntaxToken, out SyntaxKind syntaxKind) => syntaxKind = syntaxToken.Kind();`
	`21`	`+ public static void Deconstruct(this in SyntaxToken syntaxToken, out SyntaxKind syntaxKind) => syntaxKind = syntaxToken.Kind();`
`22`	`22`	`}`