Add nullable reference type annotations to System.Text.Json source gen

Directory.Build.props

@@ -349,6 +349,7 @@
                                 '$(IsPublishedAppTestProject)' != 'true' and
                                 '$(IsTestSupportProject)' != 'true' and
                                 '$(UsingMicrosoftDotNetSharedFrameworkSdk)' != 'true' and
+                                '$(MSBuildProjectExtension)' != '.pkgproj' and
                                 '$(UsingMicrosoftNoTargetsSdk)' != 'true' and
                                 '$(UsingMicrosoftTraversalSdk)' != 'true'">true</IsSourceProject>
   </PropertyGroup>

Directory.Build.targets

@@ -77,7 +77,7 @@
     <!-- Keep in sync as required by the Packaging SDK in Arcade. -->
     <Description>$(PackageDescription)</Description>
   </PropertyGroup>
-  
+
   <ItemDefinitionGroup>
     <TargetPathWithTargetPlatformMoniker>
       <IsReferenceAssemblyProject>$(IsReferenceAssemblyProject)</IsReferenceAssemblyProject>
@@ -118,14 +118,15 @@
       <_analyzerPath Condition="'$(AnalyzerLanguage)' != ''">$(_analyzerPath)/$(AnalyzerLanguage)</_analyzerPath>
     </PropertyGroup>
 
+    <!-- Filter on netstandard2.0 so that generator projects can multi-target for the purpose of enabling nullable reference type compiler checks. -->
     <ItemGroup>
-      <_AnalyzerPackFile Include="@(_BuildOutputInPackage)" IsSymbol="false" />
-      <_AnalyzerPackFile Include="@(_TargetPathsToSymbols)" IsSymbol="true" />
+      <_AnalyzerPackFile Include="@(_BuildOutputInPackage->WithMetadataValue('TargetFramework', 'netstandard2.0'))" IsSymbol="false" />
+      <_AnalyzerPackFile Include="@(_TargetPathsToSymbols->WithMetadataValue('TargetFramework', 'netstandard2.0'))" IsSymbol="true" />
       <_AnalyzerPackFile PackagePath="$(_analyzerPath)/%(TargetPath)" />
     </ItemGroup>
 
-    <Error Condition="'%(_AnalyzerPackFile.TargetFramework)' != 'netstandard2.0'"
-           Text="Analyzers must only target netstandard2.0 since they run in the compiler which targets netstandard2.0. The following files were found to target '%(_AnalyzerPackFile.TargetFramework)': @(_AnalyzerPackFile)" />
+    <Error Text="Analyzers must target netstandard2.0 since they run in the compiler which targets netstandard2.0. $(MSBuildProjectFullPath) targets '$([MSBuild]::ValueOrDefault('$(TargetFrameworks)', '$(TargetFramework)'))' instead."
+           Condition="'@(_AnalyzerPackFile)' == ''" />
   </Target>
 
   <!-- Allows building against source assemblies when the 'SkipUseReferenceAssembly' attribute is present on ProjectReference items. -->

eng/Versions.props

@@ -55,7 +55,7 @@
       The exact version is a moving target until we ship.
       It should never go ahead of the Roslyn version included in the SDK version in dotnet/arcade's global.json to avoid causing breaks in product construction.
     -->
-    <MicrosoftCodeAnalysisVersion_4_4>4.4.0-2.22423.18</MicrosoftCodeAnalysisVersion_4_4>
+    <MicrosoftCodeAnalysisVersion_4_4>4.4.0</MicrosoftCodeAnalysisVersion_4_4>
     <!-- Compatibility with the latest Visual Studio Preview release -->
     <!--
       The exact version is always a moving target. This version should never go ahead of the version of Roslyn that is included in the most recent
@@ -64,7 +64,7 @@
       When we are building from source, we care more about reducing pre-built requirements than inner-loop dev experience, so we update this to be the same version
       as MicrosoftCodeAnalysisVersion.
     -->
-    <MicrosoftCodeAnalysisVersion_LatestVS>4.4.0-2.22423.18</MicrosoftCodeAnalysisVersion_LatestVS>
+    <MicrosoftCodeAnalysisVersion_LatestVS>4.4.0</MicrosoftCodeAnalysisVersion_LatestVS>
     <MicrosoftCodeAnalysisVersion_LatestVS Condition="'$(DotNetBuildFromSource)' == 'true'">$(MicrosoftCodeAnalysisVersion)</MicrosoftCodeAnalysisVersion_LatestVS>
     <!-- Some of the analyzer dependencies used by ILLink project -->
     <MicrosoftCodeAnalysisCSharpAnalyzerTestingXunitVersion>1.0.1-beta1.21265.1</MicrosoftCodeAnalysisCSharpAnalyzerTestingXunitVersion>

eng/packaging.targets

@@ -150,7 +150,8 @@
   <Target Name="IncludeAnalyzersInPackage"
           Condition="'@(ProjectReference)' != '' and @(ProjectReference->AnyHaveMetadataValue('PackAsAnalyzer', 'true'))">
     <MSBuild Projects="@(ProjectReference->WithMetadataValue('PackAsAnalyzer', 'true'))"
-             Targets="GetAnalyzerPackFiles">
+             Targets="GetAnalyzerPackFiles"
+             RemoveProperties="SetTargetFramework">
       <Output TaskParameter="TargetOutputs" ItemName="_AnalyzerFile" />
     </MSBuild>
 

src/libraries/Common/src/Roslyn/SyntaxValueProvider_ForAttributeWithSimpleName.cs

@@ -36,10 +36,10 @@ public SyntaxTreeInfo(SyntaxTree tree, bool containsGlobalAliases, bool contains
             ContainsAttributeList = containsAttributeList;
         }
 
-        public bool Equals(SyntaxTreeInfo other)
+        public bool Equals(SyntaxTreeInfo? other)
             => Tree == other?.Tree;
 
-        public override bool Equals(object obj)
+        public override bool Equals(object? obj)
             => this.Equals(obj as SyntaxTreeInfo);
 
         public override int GetHashCode()

src/libraries/Directory.Build.targets

@@ -58,7 +58,7 @@
     <!-- By default, disable implicit framework references for NetCoreAppCurrent libraries. -->
     <DisableImplicitFrameworkReferences Condition="'$(TargetFrameworkIdentifier)' == '.NETCoreApp' and
                                                    $([MSBuild]::VersionGreaterThanOrEquals($(TargetFrameworkVersion), '$(NETCoreAppCurrentVersion)')) and
-                                                   ('$(IsNETCoreAppRef)' == 'true' or '$(IsNETCoreAppSrc)' == 'true')">true</DisableImplicitFrameworkReferences>
+                                                   ('$(IsNETCoreAppRef)' == 'true' or '$(IsNETCoreAppSrc)' == 'true' or '$(IsNETCoreAppAnalyzer)' == 'true')">true</DisableImplicitFrameworkReferences>
     <!-- Enable trimming for any source project that's part of the shared framework.
          Don't attempt to trim PNSE assemblies which are generated from the reference source. -->
     <ILLinkTrimAssembly Condition="'$(ILLinkTrimAssembly)' == '' and
@@ -95,8 +95,10 @@
       <RuntimePath>$(LibrariesAllBinArtifactsPath)</RuntimePath>
     </BinPlaceTargetFrameworks>
 
+    <!-- Source generator projects might multi-target. Make sure that only the netstandard2.0 compiled assets get binplaced. -->
     <BinPlaceDir Include="$(MicrosoftNetCoreAppRefPackDir)analyzers\dotnet\$(AnalyzerLanguage)"
-                 Condition="'$(IsNETCoreAppAnalyzer)' == 'true'" />
+                 Condition="'$(IsNETCoreAppAnalyzer)' == 'true' and
+                            '$(TargetFramework)' == 'netstandard2.0'" />
 
     <!-- Setup the shared framework directory for testing -->
     <BinPlaceTargetFrameworks Include="$(NetCoreAppCurrent)-$(TargetOS)">

src/libraries/System.Text.Json/Common/ReflectionExtensions.cs

@@ -41,9 +41,14 @@ internal static partial class ReflectionExtensions
 
         public static Type? GetCompatibleGenericBaseClass(
             this Type type,
-            Type baseType,
+            Type? baseType,
             bool sourceGenType = false)
         {
+            if (baseType is null)
+            {
+                return null;
+            }
+
             Debug.Assert(baseType.IsGenericType);
             Debug.Assert(!baseType.IsInterface);
             Debug.Assert(baseType == baseType.GetGenericTypeDefinition());

src/libraries/System.Text.Json/System.Text.Json.sln

@@ -43,7 +43,7 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Text.Json", "ref\Sys
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Text.Json", "src\System.Text.Json.csproj", "{1285FF43-F491-4BE0-B92C-37DA689CBD4B}"
 EndProject
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "System.Text.Json.FSharp.Tests", "tests\System.Text.Json.FSharp.Tests\System.Text.Json.FSharp.Tests.fsproj", "{5720BF06-2031-4AD8-B9B4-31A01E27ABB8}"
+Project("{6EC3EE1D-3C4E-46DD-8F32-0CC8E7565705}") = "System.Text.Json.FSharp.Tests", "tests\System.Text.Json.FSharp.Tests\System.Text.Json.FSharp.Tests.fsproj", "{5720BF06-2031-4AD8-B9B4-31A01E27ABB8}"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "System.Text.Json.TestLibrary.Roslyn3.11", "tests\System.Text.Json.SourceGeneration.TestLibrary\System.Text.Json.TestLibrary.Roslyn3.11.csproj", "{5C0CE30B-DD4A-4F7A-87C0-5243F0C86885}"
 EndProject
@@ -199,35 +199,35 @@ Global
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{102945CA-3736-4B2C-8E68-242A0B247F2B} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
-		{5720BF06-2031-4AD8-B9B4-31A01E27ABB8} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
-		{5C0CE30B-DD4A-4F7A-87C0-5243F0C86885} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
-		{FCA21178-0411-45D6-B597-B7BE145CEE33} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
-		{66AD4B7E-CF15-4A8F-8BF8-7E1BC6176D07} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
-		{33599A6C-F340-4E1B-9B4D-CB8946C22140} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
-		{256A4653-4287-44B3-BDEF-67FC1522ED2F} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
-		{F6A18EB5-A8CC-4A39-9E85-5FA226019C3D} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
-		{A0178BAA-A1AF-4C69-8E4A-A700A2723DDC} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
 		{73D5739C-E382-4E22-A7D3-B82705C58C74} = {0371C5D8-D5F5-4747-9810-D91D71D8C0E4}
+		{E9AA0AEB-AEAE-4B28-8D4D-17A6D7C89D17} = {E49881A9-09F6-442F-9E1D-6D87F5F837F1}
 		{282400DF-F3D8-4419-90F1-1E2F2D8B760C} = {0371C5D8-D5F5-4747-9810-D91D71D8C0E4}
+		{6E9E4359-44F8-45AA-AEC5-D0F9FFBB13D6} = {E49881A9-09F6-442F-9E1D-6D87F5F837F1}
 		{09F77672-101E-4495-9D88-29376919C121} = {0371C5D8-D5F5-4747-9810-D91D71D8C0E4}
 		{BE27618A-2916-4269-9AD5-6BC5EDC32B30} = {0371C5D8-D5F5-4747-9810-D91D71D8C0E4}
+		{1C8262DB-7355-40A8-A2EC-4EED7363134A} = {E49881A9-09F6-442F-9E1D-6D87F5F837F1}
 		{C2C7BA09-F9EE-4E43-8EE4-871CC000342C} = {0371C5D8-D5F5-4747-9810-D91D71D8C0E4}
 		{4774F56D-16A8-4ABB-8C73-5F57609F1773} = {0371C5D8-D5F5-4747-9810-D91D71D8C0E4}
+		{D05FD93A-BC51-466E-BD56-3F3D6BBE6B06} = {E49881A9-09F6-442F-9E1D-6D87F5F837F1}
 		{B6D364E7-E5DB-4CF4-B87F-3CEDA3FF7478} = {0371C5D8-D5F5-4747-9810-D91D71D8C0E4}
+		{B815304D-502E-402C-ACE1-878DB4985CCC} = {F254F143-4704-4432-9995-20D87FA8BF8D}
+		{E4B72517-C694-486A-950E-6AB03C651FDC} = {F254F143-4704-4432-9995-20D87FA8BF8D}
 		{FAB4FFF2-964D-45FF-89CC-8BB9CE618ED1} = {0371C5D8-D5F5-4747-9810-D91D71D8C0E4}
 		{C56337BB-8CBC-4EE5-AB4D-8BB0A922813E} = {0371C5D8-D5F5-4747-9810-D91D71D8C0E4}
-		{7015E94D-D20D-48C8-86D7-6A996BE99E0E} = {0371C5D8-D5F5-4747-9810-D91D71D8C0E4}
-		{E9AA0AEB-AEAE-4B28-8D4D-17A6D7C89D17} = {E49881A9-09F6-442F-9E1D-6D87F5F837F1}
-		{6E9E4359-44F8-45AA-AEC5-D0F9FFBB13D6} = {E49881A9-09F6-442F-9E1D-6D87F5F837F1}
-		{1C8262DB-7355-40A8-A2EC-4EED7363134A} = {E49881A9-09F6-442F-9E1D-6D87F5F837F1}
-		{D05FD93A-BC51-466E-BD56-3F3D6BBE6B06} = {E49881A9-09F6-442F-9E1D-6D87F5F837F1}
 		{9BCCDA15-8907-4AE3-8871-2F17775DDE4C} = {E49881A9-09F6-442F-9E1D-6D87F5F837F1}
-		{1285FF43-F491-4BE0-B92C-37DA689CBD4B} = {E49881A9-09F6-442F-9E1D-6D87F5F837F1}
-		{B815304D-502E-402C-ACE1-878DB4985CCC} = {F254F143-4704-4432-9995-20D87FA8BF8D}
-		{E4B72517-C694-486A-950E-6AB03C651FDC} = {F254F143-4704-4432-9995-20D87FA8BF8D}
 		{04AEB008-EE4F-44DE-A361-2DBD2D0FD6A4} = {F254F143-4704-4432-9995-20D87FA8BF8D}
 		{6485EED4-C313-4551-9865-8ADCED603629} = {F254F143-4704-4432-9995-20D87FA8BF8D}
 		{143AFE8A-3490-444C-A82D-6A375EB59F01} = {F254F143-4704-4432-9995-20D87FA8BF8D}
+		{7015E94D-D20D-48C8-86D7-6A996BE99E0E} = {0371C5D8-D5F5-4747-9810-D91D71D8C0E4}
+		{1285FF43-F491-4BE0-B92C-37DA689CBD4B} = {E49881A9-09F6-442F-9E1D-6D87F5F837F1}
+		{5720BF06-2031-4AD8-B9B4-31A01E27ABB8} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
+		{5C0CE30B-DD4A-4F7A-87C0-5243F0C86885} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
+		{FCA21178-0411-45D6-B597-B7BE145CEE33} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
+		{66AD4B7E-CF15-4A8F-8BF8-7E1BC6176D07} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
+		{33599A6C-F340-4E1B-9B4D-CB8946C22140} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
+		{256A4653-4287-44B3-BDEF-67FC1522ED2F} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
+		{F6A18EB5-A8CC-4A39-9E85-5FA226019C3D} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
+		{A0178BAA-A1AF-4C69-8E4A-A700A2723DDC} = {E07C6980-EB71-4D19-A80A-7BEB80B635B1}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {5868B757-D821-41FC-952E-2113A0519506}

src/libraries/System.Text.Json/gen/ContextGenerationSpec.cs

@@ -16,17 +16,17 @@ namespace System.Text.Json.SourceGeneration
     [DebuggerDisplay("ContextTypeRef={ContextTypeRef}")]
     internal sealed class ContextGenerationSpec
     {
-        public Location Location { get; init; }
+        public required Location Location { get; init; }
 
-        public JsonSourceGenerationOptionsAttribute GenerationOptions { get; init; }
+        public required JsonSourceGenerationOptionsAttribute GenerationOptions { get; init; }
 
-        public Type ContextType { get; init; }
+        public required Type ContextType { get; init; }
 
         public List<TypeGenerationSpec> RootSerializableTypes { get; } = new();
 
-        public HashSet<TypeGenerationSpec>? ImplicitlyRegisteredTypes { get; } = new();
+        public HashSet<TypeGenerationSpec> ImplicitlyRegisteredTypes { get; } = new();
 
-        public List<string> ContextClassDeclarationList { get; init; }
+        public required List<string> ContextClassDeclarationList { get; init; }
 
         /// <summary>
         /// Types that we have initiated serialization metadata generation for. A type may be discoverable in the object graph,

src/libraries/System.Text.Json/gen/JsonSourceGenerator.Emitter.cs

@@ -146,7 +146,7 @@ private void AddSource(string fileName, string source, bool isRootContextDef = f
                 int declarationCount = declarationList.Count;
                 Debug.Assert(declarationCount >= 1);
 
-                string @namespace = _currentContext.ContextType.Namespace;
+                string? @namespace = _currentContext.ContextType.Namespace;
                 bool isInGlobalNamespace = @namespace == JsonConstants.GlobalNamespaceValue;
 
                 StringBuilder sb = new(@"// <auto-generated/>
@@ -226,8 +226,9 @@ private void GenerateTypeInfo(TypeGenerationSpec typeGenerationSpec)
                         break;
                     case ClassType.Nullable:
                         {
-                            source = GenerateForNullable(typeGenerationSpec);
+                            Debug.Assert(typeGenerationSpec.NullableUnderlyingTypeMetadata != null);
 
+                            source = GenerateForNullable(typeGenerationSpec);
                             GenerateTypeInfo(typeGenerationSpec.NullableUnderlyingTypeMetadata);
                         }
                         break;
@@ -238,21 +239,26 @@ private void GenerateTypeInfo(TypeGenerationSpec typeGenerationSpec)
                         break;
                     case ClassType.Enumerable:
                         {
-                            source = GenerateForCollection(typeGenerationSpec);
+                            Debug.Assert(typeGenerationSpec.CollectionValueTypeMetadata != null);
 
+                            source = GenerateForCollection(typeGenerationSpec);
                             GenerateTypeInfo(typeGenerationSpec.CollectionValueTypeMetadata);
                         }
                         break;
                     case ClassType.Dictionary:
                         {
-                            source = GenerateForCollection(typeGenerationSpec);
+                            Debug.Assert(typeGenerationSpec.CollectionKeyTypeMetadata != null);
+                            Debug.Assert(typeGenerationSpec.CollectionValueTypeMetadata != null);
 
+                            source = GenerateForCollection(typeGenerationSpec);
                             GenerateTypeInfo(typeGenerationSpec.CollectionKeyTypeMetadata);
                             GenerateTypeInfo(typeGenerationSpec.CollectionValueTypeMetadata);
                         }
                         break;
                     case ClassType.Object:
                         {
+                            Debug.Assert(typeGenerationSpec.PropertyGenSpecList != null);
+
                             source = GenerateForObject(typeGenerationSpec);
 
                             foreach (PropertyGenerationSpec spec in typeGenerationSpec.PropertyGenSpecList)
@@ -492,6 +498,8 @@ private string GenerateForCollection(TypeGenerationSpec typeGenerationSpec)
 
             private string GenerateFastPathFuncForEnumerable(TypeGenerationSpec typeGenerationSpec)
             {
+                Debug.Assert(typeGenerationSpec.CollectionValueTypeMetadata != null);
+
                 TypeGenerationSpec valueTypeGenerationSpec = typeGenerationSpec.CollectionValueTypeMetadata;
 
                 Type elementType = valueTypeGenerationSpec.Type;
@@ -542,6 +550,9 @@ private string GenerateFastPathFuncForEnumerable(TypeGenerationSpec typeGenerati
 
             private string GenerateFastPathFuncForDictionary(TypeGenerationSpec typeGenerationSpec)
             {
+                Debug.Assert(typeGenerationSpec.CollectionKeyTypeMetadata != null);
+                Debug.Assert(typeGenerationSpec.CollectionValueTypeMetadata != null);
+
                 TypeGenerationSpec keyTypeGenerationSpec = typeGenerationSpec.CollectionKeyTypeMetadata;
                 TypeGenerationSpec valueTypeGenerationSpec = typeGenerationSpec.CollectionValueTypeMetadata;
 
@@ -758,6 +769,8 @@ string GenerateCtorParamMetadataInitFunc(TypeGenerationSpec typeGenerationSpec)
             {
                 const string parametersVarName = "parameters";
 
+                Debug.Assert(typeGenerationSpec.CtorParamGenSpecArray != null);
+
                 ParameterGenerationSpec[] parameters = typeGenerationSpec.CtorParamGenSpecArray;
                 int paramCount = parameters.Length;
                 Debug.Assert(paramCount > 0);
@@ -945,6 +958,8 @@ private static bool ShouldIncludePropertyForFastPath(PropertyGenerationSpec prop
 
             private static string GetParameterizedCtorInvocationFunc(TypeGenerationSpec typeGenerationSpec)
             {
+                Debug.Assert(typeGenerationSpec.CtorParamGenSpecArray != null);
+
                 ParameterGenerationSpec[] parameters = typeGenerationSpec.CtorParamGenSpecArray;
                 int paramCount = parameters.Length;
                 Debug.Assert(paramCount != 0);
@@ -1017,7 +1032,7 @@ private static string GenerateFastPathFuncForType(TypeGenerationSpec typeGenSpec
 }}";
             }
 
-            private static string GetEarlyNullCheckSource(bool canBeNull)
+            private static string? GetEarlyNullCheckSource(bool canBeNull)
             {
                 return canBeNull
                     ? $@"if ({ValueVarName} == null)
@@ -1355,7 +1370,8 @@ string GetParamDefaultValueAsString(object? value, Type type, string typeRef)
                 {
                     // Roslyn gives us an instance of the underlying type, which is numerical.
 #if DEBUG
-                    Type runtimeType = _generationSpec.MetadataLoadContext.Resolve(value.GetType());
+                    Type? runtimeType = _generationSpec.MetadataLoadContext.Resolve(value.GetType()!);
+                    Debug.Assert(runtimeType != null);
                     Debug.Assert(_generationSpec.IsNumberType(runtimeType));
 #endif