[ios-clr] Enable ResourceAssemblyLoadContext fallback for Apple mobile CoreCLR

src/libraries/System.Runtime.Loader/tests/DefaultContext/DefaultLoadContextTest.cs

@@ -86,6 +86,7 @@ private Assembly ResolveNullAssembly(AssemblyLoadContext sender, AssemblyName as
         // Does not apply to Mono AOT scenarios as it is expected the name of the .aotdata file matches
         // the true name of the assembly and not the physical file name.
         [ConditionalFact(typeof(PlatformDetection), nameof(PlatformDetection.IsNotMonoAOT), nameof(PlatformDetection.HasAssemblyFiles))]
+        [ActiveIssue("https://github.com/dotnet/runtime/issues/124344", typeof(PlatformDetection), nameof(PlatformDetection.IsAppleMobile), nameof(PlatformDetection.IsCoreCLR))]
         public void LoadInDefaultContext()
         {
             // This will attempt to load an assembly, by path, in the Default Load context via the Resolving event

src/libraries/System.Runtime.Loader/tests/DefaultContext/System.Runtime.Loader.DefaultContext.Tests.csproj

@@ -15,4 +15,10 @@
                       CopyToOutputDirectory="PreserveNewest"
                       TargetPath="System.Runtime.Loader.Noop.Assembly_test.dll" />
   </ItemGroup>
+
+  <Target Name="_PreserveNoopAssemblyFromTrimming" AfterTargets="ConfigureTrimming" Condition="'$(TargetsAppleMobile)' == 'true' and '$(EnableAggressiveTrimming)' == 'true'">
+    <ItemGroup>
+      <ResolvedFileToPublish TrimMode="copy" Condition="'%(FileName)%(Extension)' == 'System.Runtime.Loader.Noop.Assembly_test.dll'" />
+    </ItemGroup>
+  </Target>
 </Project>

src/libraries/System.Runtime.Loader/tests/ILLink.Descriptors.xml

@@ -2,4 +2,6 @@
   <assembly fullname="LoaderLinkTest.Dynamic" />
   <assembly fullname="ReferencedClassLib" />
   <assembly fullname="ReferencedClassLibNeutralIsSatellite" />
+  <assembly fullname="System.Runtime.Loader.Test.Assembly" />
+  <assembly fullname="System.Runtime.Loader.Test.Assembly2" />
 </linker>

src/libraries/System.Runtime.Loader/tests/RefEmitLoadContext/System.Runtime.Loader.RefEmitLoadContext.Tests.csproj

@@ -14,4 +14,10 @@
                       OutputItemType="content"
                       CopyToOutputDirectory="PreserveNewest" />
   </ItemGroup>
-</Project>
+
+  <Target Name="_PreserveNoopAssemblyFromTrimming" AfterTargets="ConfigureTrimming" Condition="'$(TargetsAppleMobile)' == 'true' and '$(EnableAggressiveTrimming)' == 'true'">
+    <ItemGroup>
+      <ResolvedFileToPublish TrimMode="copy" Condition="'%(FileName)%(Extension)' == 'System.Runtime.Loader.Noop.Assembly.dll'" />
+    </ItemGroup>
+  </Target>
+</Project>

src/libraries/System.Runtime.Loader/tests/ResourceAssemblyLoadContext.cs

@@ -31,6 +31,28 @@ protected override Assembly Load(AssemblyName assemblyName)
 
             if (asmStream == null)
             {
+                // On platforms where assemblies are deployed as files alongside the app
+                // (e.g., Apple mobile CoreCLR) rather than embedded resources, fall back
+                // to loading from the app directory.
+                string basePath = Path.Combine(AppContext.BaseDirectory, assembly);
+                if (File.Exists(basePath))
+                {
+                    if (LoadBy == LoadBy.Path)
+                    {
+                        var tempPath = Directory.CreateTempSubdirectory().FullName;
+                        string path = Path.Combine(tempPath, assembly);
+                        File.Copy(basePath, path);
+                        return LoadFromAssemblyPath(path);
+                    }
+                    else if (LoadBy == LoadBy.Stream)
+                    {
+                        using (FileStream stream = File.OpenRead(basePath))
+                        {
+                            return LoadFromStream(stream);
+                        }
+                    }
+                }
+
                 return null;
             }
 

src/libraries/tests.proj

@@ -656,7 +656,6 @@
 
     <!-- https://github.com/dotnet/runtime/issues/124344 -->
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Composition\tests\System.Composition.Tests.csproj" />
-    <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Runtime.Loader\tests\System.Runtime.Loader.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Diagnostics.StackTrace\tests\System.Diagnostics.StackTrace.Tests.csproj" />
     <ProjectExclusions Include="$(MSBuildThisFileDirectory)System.Private.Xml\tests\System.Private.Xml.Tests.csproj" />