warn if .deps.json could not be loaded

Author: smdn

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

@@ -12,6 +12,7 @@
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 using System.Runtime.Loader;
+using System.Runtime.Versioning;
 
 using Microsoft.Extensions.Logging;
 
@@ -63,9 +64,8 @@ private static TResult UsingReflectionOnlyAssembly<TArg, TResult>(
     ILogger? logger = null
   )
   {
-    using var mlc = new MetadataLoadContext(
-      new PathAssemblyDependencyResolver(assemblySource.ComponentAssemblyPath)
-    );
+    var resolver = new PathAssemblyDependencyResolver(assemblySource.ComponentAssemblyPath);
+    using var mlc = new MetadataLoadContext(resolver);
 
     logger?.LogDebug(
       "loading assembly into reflection-only context (ComponentAssemblyPath: '{ComponentAssemblyPath}')",
@@ -90,6 +90,9 @@ private static TResult UsingReflectionOnlyAssembly<TArg, TResult>(
     var assemblyName = assm.FullName;
     var assemblyTypeFullName = assm.GetType().FullName;
 
+    if (!resolver.HasDepsJsonLoaded)
+      WarnDepsJsonCouldNotBeLoaded(logger, resolver.PossibleAssemblyDepsJsonPath, assm);
+
     logger?.LogDebug(
       "loaded reflection-only assembly '{AssemblyName}' ({AssemblyTypeFullName})",
       assemblyName,
@@ -144,6 +147,9 @@ private static TResult UsingAssembly<TArg, TResult>(
     var assemblyName = assm.FullName;
     var assemblyTypeFullName = assm.GetType().FullName;
 
+    if (!alc.HasDepsJsonLoaded)
+      WarnDepsJsonCouldNotBeLoaded(logger, alc.PossibleAssemblyDepsJsonPath, assm);
+
     logger?.LogDebug(
       "loaded assembly '{AssemblyName}' ({AssemblyTypeFullName})",
       assemblyName,
@@ -162,5 +168,25 @@ private static TResult UsingAssembly<TArg, TResult>(
       logger?.LogDebug("unloaded assembly '{AssemblyName}'", assemblyName);
     }
   }
+
+  private static void WarnDepsJsonCouldNotBeLoaded(
+    ILogger? logger,
+    string possibleAssemblyDepsJsonPath,
+    Assembly assembly
+  )
+  {
+    if (logger is null)
+      return;
+
+    var targetFramework = assembly.GetAssemblyMetadataAttributeValue<TargetFrameworkAttribute, string?>();
+
+    if (targetFramework is not null && targetFramework.StartsWith(".NETFramework,", StringComparison.Ordinal))
+      return;
+
+    if (File.Exists(possibleAssemblyDepsJsonPath))
+      logger.LogWarning("dependency configuration could not be loaded: '{AssemblyDepsJsonPath}'", possibleAssemblyDepsJsonPath);
+    else
+      logger.LogWarning("dependency configuration could not be found: '{AssemblyDepsJsonPath}'", possibleAssemblyDepsJsonPath);
+  }
 }
 #endif

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

@@ -56,11 +56,12 @@ string AssemblyDepsJsonPath
   }
 
   public DependencyContext? DependencyContext { get; }
+  public string PossibleAssemblyDepsJsonPath { get; }
   private readonly ILogger? logger;
 
   public PackageDependencyAssemblyResolver(string componentAssemblyPath, ILogger? logger = null)
   {
-    (this.DependencyContext, _) = LoadDependencyContextIfDepsJsonExist(componentAssemblyPath, logger);
+    (DependencyContext, PossibleAssemblyDepsJsonPath) = LoadDependencyContextIfDepsJsonExist(componentAssemblyPath, logger);
     this.logger = logger;
   }
 

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

@@ -18,6 +18,9 @@ internal sealed class PathAssemblyDependencyResolver : PathAssemblyResolver {
   private readonly PackageDependencyAssemblyResolver packageDependencyResolver;
   private readonly ILogger? logger;
 
+  public bool HasDepsJsonLoaded => packageDependencyResolver.DependencyContext is not null;
+  public string PossibleAssemblyDepsJsonPath => packageDependencyResolver.PossibleAssemblyDepsJsonPath;
+
   public PathAssemblyDependencyResolver(string componentAssemblyPath, ILogger? logger = null)
     : base(
       Directory.GetFiles(RuntimeEnvironment.GetRuntimeDirectory(), "*.dll") // add runtime assemblies

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

@@ -16,6 +16,9 @@ internal sealed class UnloadableAssemblyLoadContext : AssemblyLoadContext {
   private readonly PackageDependencyAssemblyResolver packageDependencyResolver;
   private readonly ILogger? logger;
 
+  public bool HasDepsJsonLoaded => packageDependencyResolver.DependencyContext is not null;
+  public string PossibleAssemblyDepsJsonPath => packageDependencyResolver.PossibleAssemblyDepsJsonPath;
+
   public UnloadableAssemblyLoadContext(string componentAssemblyPath, ILogger? logger = null)
     : base(
       isCollectible: true // is required to unload assembly