enable nullable

Author: smdn

src/Smdn.Reflection.ReverseGenerating.ListApi.Core/Smdn.Reflection.ReverseGenerating.ListApi.Core.csproj

@@ -9,6 +9,7 @@ SPDX-License-Identifier: MIT
     <VersionPrefix>1.1.0</VersionPrefix>
     <VersionSuffix></VersionSuffix>
     <PackageValidationBaselineVersion>1.0.0</PackageValidationBaselineVersion>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <Import Project="..\Sdk.net7.0-preview.props" />

src/Smdn.Reflection.ReverseGenerating.ListApi.Core/Smdn.Reflection.ReverseGenerating.ListApi/ApiListWriter.cs

@@ -303,9 +303,9 @@ ApiListWriterOptions options
         // remove add/remove/raise method of events
         exceptingMembers.AddRange(e.GetMethods(true));
       }
-      else if (member.MemberType == MemberTypes.NestedType) {
-        exceptingMembers.Add(member);
-        nestedTypes.Add(member as Type);
+      else if (member.MemberType == MemberTypes.NestedType && member is Type nestedType) {
+        exceptingMembers.Add(nestedType);
+        nestedTypes.Add(nestedType);
       }
     }
 
@@ -331,7 +331,7 @@ ApiListWriterOptions options
     var memberAndDeclarations = new List<(MemberInfo Member, string Declaration)>();
 
     foreach (var member in members.Except(exceptingMembers)) {
-      string declaration = null;
+      string? declaration = null;
 
       try {
         declaration = Generator.GenerateMemberDeclaration(member, referencingNamespaces, options);

src/Smdn.Reflection.ReverseGenerating.ListApi.Core/Smdn.Reflection.ReverseGenerating.ListApi/AssemblyExtensions.cs

@@ -1,18 +1,26 @@
 // SPDX-FileCopyrightText: 2021 smdn <smdn@smdn.jp>
 // SPDX-License-Identifier: MIT
 using System;
+#if NULL_STATE_STATIC_ANALYSIS_ATTRIBUTES
+using System.Diagnostics.CodeAnalysis;
+#endif
 using System.Linq;
 using System.Reflection;
 
 namespace Smdn.Reflection.ReverseGenerating.ListApi;
 
 public static class AssemblyExtensions {
+#if NULL_STATE_STATIC_ANALYSIS_ATTRIBUTES
+  [return: MaybeNull]
+#endif
   public static TValue GetAssemblyMetadataAttributeValue<TAssemblyMetadataAttribute, TValue>(this Assembly assm)
     where TAssemblyMetadataAttribute : Attribute
-    => (TValue)assm
+    => (TValue)(
+      (assm ?? throw new ArgumentNullException(nameof(assm)))
       ?.GetCustomAttributesData()
       ?.FirstOrDefault(static d => ROCType.FullNameEquals(typeof(TAssemblyMetadataAttribute), d.AttributeType))
       ?.ConstructorArguments
       ?.FirstOrDefault()
-      .Value;
+      .Value
+    )!;
 }

src/Smdn.Reflection.ReverseGenerating.ListApi.Core/Smdn.Reflection.ReverseGenerating.ListApi/AssemblyLoader.cs

@@ -1,6 +1,9 @@
 // SPDX-FileCopyrightText: 2021 smdn <smdn@smdn.jp>
 // SPDX-License-Identifier: MIT
 using System;
+#if NULL_STATE_STATIC_ANALYSIS_ATTRIBUTES
+using System.Diagnostics.CodeAnalysis;
+#endif
 using System.IO;
 using System.Reflection;
 
@@ -9,13 +12,16 @@
 namespace Smdn.Reflection.ReverseGenerating.ListApi;
 
 public static partial class AssemblyLoader {
+#if NULL_STATE_STATIC_ANALYSIS_ATTRIBUTES
+  [return: MaybeNull]
+#endif
   public static TResult UsingAssembly<TArg, TResult>(
     FileInfo assemblyFile,
     bool loadIntoReflectionOnlyContext,
     TArg arg,
     Func<Assembly, TArg, TResult> actionWithLoadedAssembly,
-    out WeakReference context,
-    ILogger logger = null
+    out WeakReference? context,
+    ILogger? logger = null
   )
   {
     return UsingAssemblyCore(

src/Smdn.Reflection.ReverseGenerating.ListApi.Core/Smdn.Reflection.ReverseGenerating.ListApi/AssemblyLoader.netcore.cs

@@ -4,6 +4,9 @@
 
 #if NETCOREAPP3_1_OR_GREATER
 using System;
+#if NULL_STATE_STATIC_ANALYSIS_ATTRIBUTES
+using System.Diagnostics.CodeAnalysis;
+#endif
 using System.IO;
 using System.Reflection;
 using System.Runtime.CompilerServices;
@@ -17,13 +20,16 @@ namespace Smdn.Reflection.ReverseGenerating.ListApi;
 #pragma warning disable IDE0040
 partial class AssemblyLoader {
 #pragma warning restore IDE0040
+#if NULL_STATE_STATIC_ANALYSIS_ATTRIBUTES
+  [return: MaybeNull]
+#endif
   private static TResult UsingAssemblyCore<TArg, TResult>(
     FileInfo assemblyFile,
     bool loadIntoReflectionOnlyContext,
     TArg arg,
     Func<Assembly, TArg, TResult> actionWithLoadedAssembly,
-    out WeakReference context,
-    ILogger logger = null
+    out WeakReference? context,
+    ILogger? logger = null
   )
   {
     context = default;
@@ -49,9 +55,9 @@ private static TResult UsingAssemblyCore<TArg, TResult>(
 
   private sealed class PathAssemblyDependencyResolver : PathAssemblyResolver {
     private readonly AssemblyDependencyResolver dependencyResolver;
-    private readonly ILogger logger;
+    private readonly ILogger? logger;
 
-    public PathAssemblyDependencyResolver(string componentAssemblyPath, ILogger logger = null)
+    public PathAssemblyDependencyResolver(string componentAssemblyPath, ILogger? logger = null)
       : base(
         Directory.GetFiles(RuntimeEnvironment.GetRuntimeDirectory(), "*.dll") // add runtime assemblies
       )
@@ -60,7 +66,7 @@ public PathAssemblyDependencyResolver(string componentAssemblyPath, ILogger logg
       this.logger = logger;
     }
 
-    public override Assembly Resolve(MetadataLoadContext context, AssemblyName assemblyName)
+    public override Assembly? Resolve(MetadataLoadContext context, AssemblyName assemblyName)
     {
       logger?.LogDebug("attempting to load '{AssemblyName}'", assemblyName);
 
@@ -83,11 +89,14 @@ public override Assembly Resolve(MetadataLoadContext context, AssemblyName assem
     }
   }
 
+#if NULL_STATE_STATIC_ANALYSIS_ATTRIBUTES
+  [return: MaybeNull]
+#endif
   private static TResult UsingReflectionOnlyAssembly<TArg, TResult>(
     FileInfo assemblyFile,
     TArg arg,
     Func<Assembly, TArg, TResult> actionWithLoadedAssembly,
-    ILogger logger = null
+    ILogger? logger = null
   )
   {
     using var mlc = new MetadataLoadContext(
@@ -113,9 +122,9 @@ private static TResult UsingReflectionOnlyAssembly<TArg, TResult>(
 
   private sealed class UnloadableAssemblyLoadContext : AssemblyLoadContext {
     private readonly AssemblyDependencyResolver dependencyResolver;
-    private readonly ILogger logger;
+    private readonly ILogger? logger;
 
-    public UnloadableAssemblyLoadContext(string componentAssemblyPath, ILogger logger = null)
+    public UnloadableAssemblyLoadContext(string componentAssemblyPath, ILogger? logger = null)
       : base(
         isCollectible: true // is required to unload assembly
       )
@@ -124,7 +133,7 @@ public UnloadableAssemblyLoadContext(string componentAssemblyPath, ILogger logge
       this.logger = logger;
     }
 
-    protected override Assembly Load(AssemblyName name)
+    protected override Assembly? Load(AssemblyName name)
     {
       var assemblyPath = dependencyResolver.ResolveAssemblyToPath(name);
 
@@ -140,13 +149,16 @@ protected override Assembly Load(AssemblyName name)
     }
   }
 
+#if NULL_STATE_STATIC_ANALYSIS_ATTRIBUTES
+  [return: MaybeNull]
+#endif
   [MethodImpl(MethodImplOptions.NoInlining)]
   private static TResult UsingAssembly<TArg, TResult>(
     FileInfo assemblyFile,
     TArg arg,
     Func<Assembly, TArg, TResult> actionWithLoadedAssembly,
-    out WeakReference context,
-    ILogger logger = null
+    out WeakReference? context,
+    ILogger? logger = null
   )
   {
     context = null;

src/Smdn.Reflection.ReverseGenerating.ListApi.Core/Smdn.Reflection.ReverseGenerating.ListApi/AssemblyLoader.netframework.cs

@@ -32,13 +32,14 @@ public override Assembly LoadAssembly(FileInfo assemblyFile)
     }
   }
 
+  [return: MaybeNull]
   private static TResult UsingAssemblyCore<TArg, TResult>(
     FileInfo assemblyFile,
     bool loadIntoReflectionOnlyContext,
     TArg arg,
     Func<Assembly, TArg, TResult> actionWithLoadedAssembly,
-    out WeakReference context,
-    ILogger logger = null
+    out WeakReference? context,
+    ILogger? logger = null
   )
   {
     context = null;

src/Smdn.Reflection.ReverseGenerating.ListApi.Core/Smdn.Reflection.ReverseGenerating.ListApi/FrameworkMonikers.cs

@@ -1,6 +1,9 @@
 // SPDX-FileCopyrightText: 2021 smdn <smdn@smdn.jp>
 // SPDX-License-Identifier: MIT
 using System;
+#if NULL_STATE_STATIC_ANALYSIS_ATTRIBUTES
+using System.Diagnostics.CodeAnalysis;
+#endif
 using System.Runtime.Versioning;
 
 namespace Smdn.Reflection.ReverseGenerating.ListApi;
@@ -14,9 +17,12 @@ public static class FrameworkMonikers {
   public static bool TryGetMoniker(
     FrameworkName frameworkName,
 #pragma warning disable IDE0060, SA1305
-    string osSpecifier,
+    string? osSpecifier,
 #pragma warning restore IDE0060, SA1305
-    out string frameworkMoniker
+#if NULL_STATE_STATIC_ANALYSIS_ATTRIBUTES
+    [NotNullWhen(true)]
+#endif
+    out string? frameworkMoniker
   )
   {
     if (frameworkName is null)

src/Smdn.Reflection.ReverseGenerating.ListApi.Core/Smdn.Reflection.ReverseGenerating.ListApi/MemberInfoComparer.cs

@@ -18,7 +18,7 @@ public MemberInfoComparer(int orderOfStaticMember, int orderOfInstanceMember)
     this.orderOfInstanceMember = orderOfInstanceMember;
   }
 
-  public int Compare(MemberInfo x, MemberInfo y)
+  public int Compare(MemberInfo? x, MemberInfo? y)
   {
     var ox = GetOrder(x);
     var oy = GetOrder(y);
@@ -28,7 +28,7 @@ public int Compare(MemberInfo x, MemberInfo y)
 
   private int GetStaticMemberOrder(bool isStatic) => isStatic ? orderOfStaticMember : orderOfInstanceMember;
 
-  public int GetOrder(MemberInfo member)
+  public int GetOrder(MemberInfo? member)
     => member switch {
 #pragma warning disable IDE0055
       null                  => 0,