Add unsupported language detection to the STJ source generator (#87950)

* Make the STJ source generator detect unsupported C# language versions and emit error diagnostics. * Fix whitespace * Do not hardcode minimal lang version on diagnostic string.
dotnet · Jun 23, 2023 · 478130b · 478130b
1 parent 5316458
commit 478130b
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Showing 21 changed files with 368 additions and 268 deletions.
diff --git a/src/libraries/System.Text.Json/gen/Helpers/RoslynExtensions.cs b/src/libraries/System.Text.Json/gen/Helpers/RoslynExtensions.cs
@@ -15,6 +15,9 @@ namespace System.Text.Json.SourceGeneration
 {
     internal static class RoslynExtensions
     {
+        public static LanguageVersion? GetLanguageVersion(this Compilation compilation)
+            => compilation is CSharpCompilation csc ? csc.LanguageVersion : null;
+
         public static INamedTypeSymbol? GetBestTypeByMetadataName(this Compilation compilation, Type type)
         {
             Debug.Assert(!type.IsArray, "Resolution logic only capable of handling named types.");

diff --git a/src/libraries/System.Text.Json/gen/JsonSourceGenerator.DiagnosticDescriptors.cs b/src/libraries/System.Text.Json/gen/JsonSourceGenerator.DiagnosticDescriptors.cs
@@ -88,6 +88,14 @@ internal static class DiagnosticDescriptors
                 category: JsonConstants.SystemTextJsonSourceGenerationName,
                 defaultSeverity: DiagnosticSeverity.Warning,
                 isEnabledByDefault: true);
+
+            public static DiagnosticDescriptor JsonUnsupportedLanguageVersion { get; } = new DiagnosticDescriptor(
+                id: "SYSLIB1042",
+                title: new LocalizableResourceString(nameof(SR.JsonUnsupportedLanguageVersionTitle), SR.ResourceManager, typeof(FxResources.System.Text.Json.SourceGeneration.SR)),
+                messageFormat: new LocalizableResourceString(nameof(SR.JsonUnsupportedLanguageVersionMessageFormat), SR.ResourceManager, typeof(FxResources.System.Text.Json.SourceGeneration.SR)),
+                category: JsonConstants.SystemTextJsonSourceGenerationName,
+                defaultSeverity: DiagnosticSeverity.Error,
+                isEnabledByDefault: true);
         }
     }
 }
diff --git a/src/libraries/System.Text.Json/gen/JsonSourceGenerator.Parser.cs b/src/libraries/System.Text.Json/gen/JsonSourceGenerator.Parser.cs
@@ -6,7 +6,6 @@
 using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Linq;
-using System.Reflection;
 using System.Text.Json.Serialization;
 using System.Threading;
 using Microsoft.CodeAnalysis;
@@ -17,6 +16,9 @@ namespace System.Text.Json.SourceGeneration
 {
     public sealed partial class JsonSourceGenerator
     {
+        // The source generator requires NRT and init-only property support.
+        private const LanguageVersion MinimumSupportedLanguageVersion = LanguageVersion.CSharp9;
+
         private sealed class Parser
         {
             private const string SystemTextJsonNamespace = "System.Text.Json";
@@ -104,6 +106,14 @@ public Parser(KnownTypeSymbols knownSymbols)
                     return null;
                 }
 
+                LanguageVersion? langVersion = _knownSymbols.Compilation.GetLanguageVersion();
+                if (langVersion is null or < MinimumSupportedLanguageVersion)
+                {
+                    // Unsupported lang version should be the first (and only) diagnostic emitted by the generator.
+                    ReportDiagnostic(DiagnosticDescriptors.JsonUnsupportedLanguageVersion, contextTypeSymbol.GetDiagnosticLocation(), langVersion?.ToDisplayString(), MinimumSupportedLanguageVersion.ToDisplayString());
+                    return null;
+                }
+
                 Location contextLocation = contextClassDeclaration.GetLocation();
                 if (!TryGetNestedTypeDeclarations(contextClassDeclaration, semanticModel, cancellationToken, out List<string>? classDeclarationList))
                 {

diff --git a/src/libraries/System.Text.Json/gen/Resources/Strings.resx b/src/libraries/System.Text.Json/gen/Resources/Strings.resx
@@ -183,4 +183,10 @@
   <data name="JsonConverterAttributeInvalidTypeMessageFormat" xml:space="preserve">
     <value>The 'JsonConverterAttribute' type '{0}' specified on member '{1}' is not a converter type or does not contain an accessible parameterless constructor.</value>
   </data>
+  <data name="JsonUnsupportedLanguageVersionTitle" xml:space="preserve">
+    <value>C# language version not supported by the source generator.</value>
+  </data>
+  <data name="JsonUnsupportedLanguageVersionMessageFormat" xml:space="preserve">
+    <value>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</value>
+  </data>
 </root>
diff --git a/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.cs.xlf b/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.cs.xlf
@@ -82,6 +82,16 @@
         <target state="translated">Neobecný objekt JsonStringEnumConverter vyžaduje dynamický kód.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionMessageFormat">
+        <source>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</source>
+        <target state="new">The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionTitle">
+        <source>C# language version not supported by the source generator.</source>
+        <target state="new">C# language version not supported by the source generator.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">Typ {0} má více konstruktorů anotovaných s JsonConstructorAttribute. </target>

diff --git a/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.de.xlf b/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.de.xlf
@@ -82,6 +82,16 @@
         <target state="translated">Der nicht generische "JsonStringEnumConverter" erfordert dynamischen Code.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionMessageFormat">
+        <source>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</source>
+        <target state="new">The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionTitle">
+        <source>C# language version not supported by the source generator.</source>
+        <target state="new">C# language version not supported by the source generator.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">Typ "{0}" weist mehrere Konstruktoren mit dem Kommentar "JsonConstructorAttribute" auf.</target>

diff --git a/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.es.xlf b/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.es.xlf
@@ -82,6 +82,16 @@
         <target state="translated">El elemento 'JsonStringEnumConverter' no genérico requiere código dinámico.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionMessageFormat">
+        <source>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</source>
+        <target state="new">The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionTitle">
+        <source>C# language version not supported by the source generator.</source>
+        <target state="new">C# language version not supported by the source generator.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">El tipo '{0}' tiene varios constructores anotados con 'JsonConstructorAttribute'.</target>

diff --git a/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.fr.xlf b/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.fr.xlf
@@ -82,6 +82,16 @@
         <target state="translated">Le 'JsonStringEnumConverter' non générique requiert du code dynamique.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionMessageFormat">
+        <source>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</source>
+        <target state="new">The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionTitle">
+        <source>C# language version not supported by the source generator.</source>
+        <target state="new">C# language version not supported by the source generator.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">Le type' {0} 'a plusieurs constructeurs annotés avec’JsonConstructorAttribute'.</target>

diff --git a/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.it.xlf b/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.it.xlf
@@ -82,6 +82,16 @@
         <target state="translated">L'elemento 'JsonStringEnumConverter' non generico richiede un codice dinamico.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionMessageFormat">
+        <source>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</source>
+        <target state="new">The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionTitle">
+        <source>C# language version not supported by the source generator.</source>
+        <target state="new">C# language version not supported by the source generator.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">Il tipo '{0}' contiene più costruttori che presentano l'annotazione 'JsonConstructorAttribute'.</target>

diff --git a/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.ja.xlf b/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.ja.xlf
@@ -82,6 +82,16 @@
         <target state="translated">非ジェネリック 'JsonStringEnumConverter' には動的コードが必要です。</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionMessageFormat">
+        <source>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</source>
+        <target state="new">The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionTitle">
+        <source>C# language version not supported by the source generator.</source>
+        <target state="new">C# language version not supported by the source generator.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">型 '{0}' には、'JsonConstructorAttribute' で注釈が付けられた複数のコンストラクターがあります。</target>

diff --git a/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.ko.xlf b/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.ko.xlf
@@ -82,6 +82,16 @@
         <target state="translated">제네릭이 아닌 'JsonStringEnumConverter'에는 동적 코드가 필요합니다.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionMessageFormat">
+        <source>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</source>
+        <target state="new">The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionTitle">
+        <source>C# language version not supported by the source generator.</source>
+        <target state="new">C# language version not supported by the source generator.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">'{0}' 형식에 'JsonConstructorAttribute'로 주석이 추가된 여러 생성자가 있습니다.</target>

diff --git a/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.pl.xlf b/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.pl.xlf
@@ -82,6 +82,16 @@
         <target state="translated">Nieogólny element „JsonStringEnumConverter” wymaga dynamicznego kodu.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionMessageFormat">
+        <source>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</source>
+        <target state="new">The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionTitle">
+        <source>C# language version not supported by the source generator.</source>
+        <target state="new">C# language version not supported by the source generator.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">Typ "{0}" ma wiele konstruktorów z adnotacją "JsonConstructorAttribute".</target>

diff --git a/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.pt-BR.xlf b/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.pt-BR.xlf
@@ -82,6 +82,16 @@
         <target state="translated">O "JsonStringEnumConverter" não genérico requer código dinâmico.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionMessageFormat">
+        <source>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</source>
+        <target state="new">The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionTitle">
+        <source>C# language version not supported by the source generator.</source>
+        <target state="new">C# language version not supported by the source generator.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">O tipo '{0}' tem vários construtores anotados com 'JsonConstructorAttribute'.</target>

diff --git a/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.ru.xlf b/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.ru.xlf
@@ -82,6 +82,16 @@
         <target state="translated">Для неуниверсального параметра JsonStringEnumConverter требуется динамический код.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionMessageFormat">
+        <source>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</source>
+        <target state="new">The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionTitle">
+        <source>C# language version not supported by the source generator.</source>
+        <target state="new">C# language version not supported by the source generator.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">Тип "{0}" имеет несколько конструкторов, аннотированных с использованием JsonConstructorAttribute.</target>

diff --git a/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.tr.xlf b/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.tr.xlf
@@ -82,6 +82,16 @@
         <target state="translated">Genel olmayan 'JsonStringEnumConverter' parametresi dinamik kod gerektirir.</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionMessageFormat">
+        <source>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</source>
+        <target state="new">The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionTitle">
+        <source>C# language version not supported by the source generator.</source>
+        <target state="new">C# language version not supported by the source generator.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">'{0}' türünün 'JsonConstructorAttribute' ile açıklanan birden çok oluşturucusu var.</target>

diff --git a/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.zh-Hans.xlf b/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.zh-Hans.xlf
@@ -82,6 +82,16 @@
         <target state="translated">非泛型 "JsonStringEnumConverter" 需要动态代码。</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionMessageFormat">
+        <source>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</source>
+        <target state="new">The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionTitle">
+        <source>C# language version not supported by the source generator.</source>
+        <target state="new">C# language version not supported by the source generator.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">类型“{0}”具有用 “JsonConstructorAttribute” 批注的多个构造函数。</target>

diff --git a/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.zh-Hant.xlf b/src/libraries/System.Text.Json/gen/Resources/xlf/Strings.zh-Hant.xlf
@@ -82,6 +82,16 @@
         <target state="translated">非一般 'JsonStringEnumConverter' 需要動態程式碼。</target>
         <note />
       </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionMessageFormat">
+        <source>The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</source>
+        <target state="new">The System.Text.Json source generator is not available in C# '{0}'. Please use language version {1} or greater.</target>
+        <note />
+      </trans-unit>
+      <trans-unit id="JsonUnsupportedLanguageVersionTitle">
+        <source>C# language version not supported by the source generator.</source>
+        <target state="new">C# language version not supported by the source generator.</target>
+        <note />
+      </trans-unit>
       <trans-unit id="MultipleJsonConstructorAttributeFormat">
         <source>Type '{0}' has multiple constructors annotated with 'JsonConstructorAttribute'.</source>
         <target state="translated">類型 '{0}' 包含多個以 'JsonConstructorAttribute' 註解的建構函式。</target>