Revert Roslyn to '4.3.0'

Author: Sergio0694

src/PolySharp.SourceGenerators/Diagnostics/Analyzers/UnsupportedCSharpLanguageVersionAnalyzer.cs

@@ -18,7 +18,7 @@ namespace PolySharp.SourceGenerators;
 public sealed partial class UnsupportedCSharpLanguageVersionAnalyzer : DiagnosticAnalyzer
 {
     /// <inheritdoc/>
-    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; } = [UnsupportedCSharpLanguageVersionError];
+    public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics { get; } = ImmutableArray.Create(UnsupportedCSharpLanguageVersionError);
 
     /// <inheritdoc/>
     public override void Initialize(AnalysisContext context)

src/PolySharp.SourceGenerators/Diagnostics/DiagnosticDescriptors.cs

@@ -5,6 +5,8 @@
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 
+#pragma warning disable IDE0090 // Use 'new DiagnosticDescriptor(...)'
+
 namespace PolySharp.SourceGenerators.Diagnostics;
 
 /// <summary>
@@ -18,7 +20,7 @@ internal static class DiagnosticDescriptors
     /// Format: <c>"The value "{0}" is not valid for property "{1}" (it has to be a valid MSBuild bool value)"</c>.
     /// </para>
     /// </summary>
-    public static readonly DiagnosticDescriptor InvalidBoolMSBuildProperty = new(
+    public static readonly DiagnosticDescriptor InvalidBoolMSBuildProperty = new DiagnosticDescriptor(
         id: "POLYSP0001",
         title: "Invalid PolySharp bool MSBuild property",
         messageFormat: "The value \"{0}\" is not valid for property \"{1}\" (it has to be a valid MSBuild bool value)",
@@ -34,7 +36,7 @@ internal static class DiagnosticDescriptors
     /// Format: <c>"The fully qualified metadata name "{0}" used in property "{1}" is not valid, and it does not match any available polyfill type"</c>.
     /// </para>
     /// </summary>
-    public static readonly DiagnosticDescriptor InvalidPolyfillFullyQualifiedMetadataName = new(
+    public static readonly DiagnosticDescriptor InvalidPolyfillFullyQualifiedMetadataName = new DiagnosticDescriptor(
         id: "POLYSP0002",
         title: "Invalid fully qualified metadata name for polyfill",
         messageFormat: "The fully qualified metadata name \"{0}\" used in property \"{1}\" is not a valid fully qualified type name, or it does not match any available polyfill type",
@@ -47,14 +49,13 @@ internal static class DiagnosticDescriptors
     /// <summary>
     /// Gets a <see cref="DiagnosticDescriptor"/> indicating when an unsupported C# language version is being used.
     /// </summary>
-    public static readonly DiagnosticDescriptor UnsupportedCSharpLanguageVersionError = new(
+    public static readonly DiagnosticDescriptor UnsupportedCSharpLanguageVersionError = new DiagnosticDescriptor(
         id: "POLYSP0003",
         title: "Unsupported C# language version",
         messageFormat: "The source generator features from PolySharp require consuming projects to set the C# language version to at least C# 8.0",
         category: typeof(CSharpParseOptions).FullName,
         defaultSeverity: DiagnosticSeverity.Warning,
         isEnabledByDefault: true,
         description: "The source generator features from PolySharp 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.",
-        helpLinkUri: "https://github.com/Sergio0694/PolySharp",
-        customTags: WellKnownDiagnosticTags.CompilationEnd);
+        helpLinkUri: "https://github.com/Sergio0694/PolySharp");
 }

src/PolySharp.SourceGenerators/Extensions/AnalyzerConfigOptionsProviderExtensions.cs

@@ -71,6 +71,6 @@ public static ImmutableArray<string> GetStringArrayMSBuildProperty(this Analyzer
             return builder.ToImmutable();
         }
 
-        return [];
+        return ImmutableArray<string>.Empty;
     }
 }

src/PolySharp.SourceGenerators/Extensions/DiagnosticsExtensions.cs

@@ -5,7 +5,7 @@
 namespace PolySharp.SourceGenerators.Extensions;
 
 /// <summary>
-/// Extension methods for <see cref="DiagnosticInfo"/>, in various scenarios.
+/// Extension methods for <see cref="GeneratorExecutionContext"/>, specifically for reporting diagnostics.
 /// </summary>
 internal static class DiagnosticsExtensions
 {

src/PolySharp.SourceGenerators/PolySharp.SourceGenerators.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFramework>netstandard2.0</TargetFramework>
@@ -7,7 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.14.0" PrivateAssets="all" Pack="false" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.3.1" PrivateAssets="all" Pack="false" />
   </ItemGroup>
 
   <ItemGroup>

src/PolySharp.SourceGenerators/PolySharp.targets

@@ -7,7 +7,7 @@
     </ItemGroup>
   </Target>
 
-  <!-- Remove the analyzer if using Roslyn < 4.14 (PolySharp's generators require Roslyn 4.14) -->
+  <!-- Remove the analyzer if using Roslyn < 4.3 (PolySharp's generators require Roslyn 4.3) -->
   <Target Name="_PolySharpRemoveAnalyzersForRoslyn3"
           Condition="'$(CSharpCoreTargetsPath)' != ''"
           AfterTargets="ResolvePackageDependenciesForBuild;ResolveNuGetPackageAssets"
@@ -29,10 +29,10 @@
       <PolySharpCurrentCompilerVersion>@(PolySharpCurrentCompilerAssemblyIdentity->'%(Version)')</PolySharpCurrentCompilerVersion>
 
       <!-- The CurrentCompilerVersionIsNotNewEnough property can now be defined based on the Roslyn assembly version -->
-      <PolySharpCurrentCompilerVersionIsNotNewEnough Condition="$([MSBuild]::VersionLessThan($(PolySharpCurrentCompilerVersion), 4.14))">true</PolySharpCurrentCompilerVersionIsNotNewEnough>
+      <PolySharpCurrentCompilerVersionIsNotNewEnough Condition="$([MSBuild]::VersionLessThan($(PolySharpCurrentCompilerVersion), 4.3))">true</PolySharpCurrentCompilerVersionIsNotNewEnough>
     </PropertyGroup>
 
-    <!-- If the Roslyn version is < 4.14, disable the source generators -->
+    <!-- If the Roslyn version is < 4.3, disable the source generators -->
     <ItemGroup Condition ="'$(PolySharpCurrentCompilerVersionIsNotNewEnough)' == 'true'">
       <Analyzer Remove="@(_PolySharpAnalyzer)"/>
     </ItemGroup>
@@ -44,7 +44,7 @@
     -->
     <Error Condition ="'$(PolySharpCurrentCompilerVersionIsNotNewEnough)' == 'true'"
            Code="POLYSPCFG0001"
-           Text="The PolySharp source generators have been disabled on the current configuration, as they need Roslyn 4.14 in order to work. PolySharp requires the source generators to run in order to generate polyfills, so the library cannot be used without a more up to date IDE (eg. VS 2022 17.14 or greater) or .NET SDK version (.NET 8.0.411 SDK or greater)."/>  
+           Text="The PolySharp source generators have been disabled on the current configuration, as they need Roslyn 4.3 in order to work. PolySharp requires the source generators to run in order to generate polyfills, so the library cannot be used without a more up to date IDE (eg. VS 2022 17.3 or greater) or .NET SDK version (.NET 6.0.400 SDK or greater)."/>  
   </Target>
 
   <!-- Remove the analyzer if Roslyn is missing -->

src/PolySharp.SourceGenerators/PolyfillsGenerator.Polyfills.cs

@@ -35,23 +35,23 @@ from string resourceName in typeof(PolyfillsGenerator).Assembly.GetManifestResou
     /// <summary>
     /// The collection of fully qualified type names for language support types.
     /// </summary>
-    private static readonly ImmutableArray<string> LanguageSupportTypeNames = [..
+    private static readonly ImmutableArray<string> LanguageSupportTypeNames = ImmutableArray.CreateRange(
         from KeyValuePair<string, string> resource in FullyQualifiedTypeNamesToResourceNames
         where resource.Value.StartsWith("PolySharp.SourceGenerators.EmbeddedResources.LanguageSupport.")
-        select resource.Key];
+        select resource.Key);
 
     /// <summary>
     /// The collection of fully qualified type names for runtime supported types.
     /// </summary>
-    private static readonly ImmutableArray<string> RuntimeSupportedTypeNames = [..
+    private static readonly ImmutableArray<string> RuntimeSupportedTypeNames = ImmutableArray.CreateRange(
         from KeyValuePair<string, string> resource in FullyQualifiedTypeNamesToResourceNames
         where resource.Value.StartsWith("PolySharp.SourceGenerators.EmbeddedResources.RuntimeSupported.")
-        select resource.Key];
+        select resource.Key);
 
     /// <summary>
     /// The collection of all fully qualified type names for available polyfill types.
     /// </summary>
-    private static readonly ImmutableArray<string> AllSupportTypeNames = [.. LanguageSupportTypeNames.Concat(RuntimeSupportedTypeNames)];
+    private static readonly ImmutableArray<string> AllSupportTypeNames = ImmutableArray.CreateRange(LanguageSupportTypeNames.Concat(RuntimeSupportedTypeNames));
 
     /// <summary>
     /// The <see cref="Regex"/> to find all <see cref="System.Runtime.CompilerServices.MethodImplOptions"/> uses.
@@ -117,7 +117,7 @@ private static ImmutableArray<AvailableType> GetAvailableTypes(Compilation compi
         // A minimum of C# 8.0 is required to benefit from the polyfills
         if (!compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp8))
         {
-            return [];
+            return ImmutableArray<AvailableType>.Empty;
         }
 
         // Helper function to check whether a type is available

src/PolySharp.SourceGenerators/PolyfillsGenerator.TypeForwards.cs

@@ -14,13 +14,11 @@ partial class PolyfillsGenerator
     /// <summary>
     /// The collection of fully qualified type names for types that could require a <c>modreq</c>.
     /// </summary>
-    private static readonly ImmutableArray<string> ModreqCandidateFullyQualifiedTypeNames =
-    [
+    private static readonly ImmutableArray<string> ModreqCandidateFullyQualifiedTypeNames = ImmutableArray.Create(
         "System.Index",
         "System.Range",
         "System.Runtime.CompilerServices.IsExternalInit",
-        "System.Runtime.CompilerServices.RequiresLocationAttribute",
-    ];
+        "System.Runtime.CompilerServices.RequiresLocationAttribute");
 
     /// <summary>
     /// Gets the types from the BCL that should potentially receive type forwards.
@@ -33,7 +31,7 @@ private static ImmutableArray<string> GetCoreLibTypes(Compilation compilation, C
         // Same check as when generating polyfills (if none can be generated, there's no need for type forwards)
         if (!compilation.HasLanguageVersionAtLeastEqualTo(LanguageVersion.CSharp8))
         {
-            return [];
+            return ImmutableArray<string>.Empty;
         }
 
         IAssemblySymbol coreLibAssemblySymbol = compilation.GetSpecialType(SpecialType.System_Object).ContainingAssembly;