From a507d4eabf9803db82c949c8e214894934b9be5d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20Strehovsk=C3=BD?=
 <MichalStrehovsky@users.noreply.github.com>
Date: Fri, 26 Apr 2024 08:27:59 +0200
Subject: [PATCH] Start running System.Runtime trimming tests

---
 .../TrimmingTests/InvariantGlobalizationTrue.cs | 17 +++++++++++++++++
 .../System.Runtime.TrimmingTests.proj           |  6 ++++++
 src/libraries/tests.proj                        |  1 -
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/libraries/System.Runtime/tests/System.Runtime.Tests/TrimmingTests/InvariantGlobalizationTrue.cs b/src/libraries/System.Runtime/tests/System.Runtime.Tests/TrimmingTests/InvariantGlobalizationTrue.cs
index fe878e3a7459d8..27ab1b136b5a4f 100644
--- a/src/libraries/System.Runtime/tests/System.Runtime.Tests/TrimmingTests/InvariantGlobalizationTrue.cs
+++ b/src/libraries/System.Runtime/tests/System.Runtime.Tests/TrimmingTests/InvariantGlobalizationTrue.cs
@@ -4,6 +4,7 @@
 using System;
 using System.Globalization;
 using System.Reflection;
+using System.Runtime.CompilerServices;
 
 /// <summary>
 /// Ensures setting InvariantGlobalization = true still works in a trimmed app.
@@ -27,6 +28,18 @@ static int Main(string[] args)
         {
             return -3;
         }
+
+        // The rest of this code depends on a property of IL level trimming that keeps reflection
+        // metadata for anything that is statically reachable. It's not applicable if we're not doing that
+        // kind of trimming. Approximate what kind of trimming are we doing.
+        if (GetMethodSecretly(typeof(Program), nameof(GetCoreLibType)) == null)
+        {
+            // Sanity check: we only expect this for native AOT; IsDynamicCodeSupported approximates that.
+            if (RuntimeFeature.IsDynamicCodeSupported)
+                throw new Exception();
+
+            return 100;
+        }
         
         // Ensure the internal GlobalizationMode class is trimmed correctly.
         Type globalizationMode = GetCoreLibType("System.Globalization.GlobalizationMode");
@@ -65,4 +78,8 @@ static int Main(string[] args)
     // The intention of this method is to ensure the trimmer doesn't preserve the Type.
     private static Type GetCoreLibType(string name) =>
         typeof(object).Assembly.GetType(name, throwOnError: false);
+
+    // The intention is to look for a method on a type in a way that trimming cannot detect.
+    private static MethodBase GetMethodSecretly(Type type, string name) =>
+        type.GetMethod(name, BindingFlags.Static | BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
 }
diff --git a/src/libraries/System.Runtime/tests/System.Runtime.Tests/TrimmingTests/System.Runtime.TrimmingTests.proj b/src/libraries/System.Runtime/tests/System.Runtime.Tests/TrimmingTests/System.Runtime.TrimmingTests.proj
index c9c42b2c20234e..6cfdea28f5e0bd 100644
--- a/src/libraries/System.Runtime/tests/System.Runtime.Tests/TrimmingTests/System.Runtime.TrimmingTests.proj
+++ b/src/libraries/System.Runtime/tests/System.Runtime.Tests/TrimmingTests/System.Runtime.TrimmingTests.proj
@@ -43,6 +43,8 @@
        and tested with this test. Issue https://github.com/dotnet/runtime/issues/48849 is
        tracking investigation on why this test is failing if not skipped. -->
       <SkipOnTestRuntimes>browser-wasm</SkipOnTestRuntimes>
+      <!-- https://github.com/dotnet/runtime/issues/68714 -->
+      <NativeAotIncompatible>true</NativeAotIncompatible>
     </TestConsoleAppSourceFiles>
     <TestConsoleAppSourceFiles Include="VerifyResourcesGetTrimmedTest.cs">
       <!-- Setting the Trimming feature switch to make sure that the Resources get trimmed by the trimmer
@@ -51,6 +53,8 @@
     </TestConsoleAppSourceFiles>
     <TestConsoleAppSourceFiles Include="TypeBuilderComDisabled.cs">
       <DisabledProperties>BuiltInComInteropSupport</DisabledProperties>
+      <!-- Reflection.Emit doesn't work with native AOT -->
+      <NativeAotIncompatible>true</NativeAotIncompatible>
     </TestConsoleAppSourceFiles>
     <TestConsoleAppSourceFiles Include="NullabilityInfoContextSupportFalse.cs">
       <DisabledProperties>NullabilityInfoContextSupport</DisabledProperties>
@@ -62,6 +66,8 @@
   <ItemGroup Condition="'$(TargetsWindows)' == 'true'">
     <TestConsoleAppSourceFiles Include="UseWindowsThreadPoolFalse.cs">
       <DisabledFeatureSwitches>System.Threading.ThreadPool.UseWindowsThreadPool</DisabledFeatureSwitches>
+      <!-- https://github.com/dotnet/runtime/issues/101591 -->
+      <NativeAotIncompatible>true</NativeAotIncompatible>
     </TestConsoleAppSourceFiles>
     <TestConsoleAppSourceFiles Include="UseWindowsThreadPoolTrue.cs">
       <EnabledFeatureSwitches>System.Threading.ThreadPool.UseWindowsThreadPool</EnabledFeatureSwitches>
diff --git a/src/libraries/tests.proj b/src/libraries/tests.proj
index 7106a44c89e967..87614b7836eaf2 100644
--- a/src/libraries/tests.proj
+++ b/src/libraries/tests.proj
@@ -652,7 +652,6 @@
     <ProjectExclusions Condition="'$(RunNativeAotTestApps)' == 'true'" Include="$(MSBuildThisFileDirectory)\System.Private.Xml.Linq\tests\TrimmingTests\System.Xml.Linq.TrimmingTests.proj" />
     <ProjectExclusions Condition="'$(RunNativeAotTestApps)' == 'true'" Include="$(MSBuildThisFileDirectory)\System.Linq.Expressions\tests\TrimmingTests\System.Linq.Expressions.TrimmingTests.proj" />
     <ProjectExclusions Condition="'$(RunNativeAotTestApps)' == 'true'" Include="$(MSBuildThisFileDirectory)\System.Private.Xml\tests\TrimmingTests\System.Private.Xml.TrimmingTests.proj" />
-    <ProjectExclusions Condition="'$(RunNativeAotTestApps)' == 'true'" Include="$(MSBuildThisFileDirectory)\System.Runtime\tests\System.Runtime.Tests\TrimmingTests\System.Runtime.TrimmingTests.proj" />
 
     <TrimmingTestProjects Include="$(MSBuildThisFileDirectory)*\tests\**\*.TrimmingTests.proj"
                       Exclude="@(ProjectExclusions)"