From b1c4dfa7ddb4b9cab8dc8be8c2b74c1d8f0c9adc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Michal=20Strehovsk=C3=BD?=
 <MichalStrehovsky@users.noreply.github.com>
Date: Tue, 16 Jan 2024 19:16:04 +0900
Subject: [PATCH] Make startup hooks kind of work with native AOT (#96894)

Fixes #96052.

Since we compile startup hooks anyway, just add a call to it. It will be deadcoded by default. Can be enabled and then it will at least work for hooks that were part of the app. It will throw PNSE for random file paths.
---
 .../src/ILLink/ILLink.Substitutions.xml       |  3 ---
 .../src/System.Private.CoreLib.csproj         |  1 +
 .../System/StartupHookProvider.NativeAot.cs   | 19 ++++++++++++++++
 .../tools/aot/ILCompiler/repro/repro.csproj   |  1 +
 .../ILLink/ILLink.Substitutions.Shared.xml    |  3 +++
 .../nativeaot/StartupHook/StartupHook.cs      | 22 +++++++++++++++++++
 .../nativeaot/StartupHook/StartupHook.csproj  | 16 ++++++++++++++
 7 files changed, 62 insertions(+), 3 deletions(-)
 create mode 100644 src/coreclr/nativeaot/System.Private.CoreLib/src/System/StartupHookProvider.NativeAot.cs
 create mode 100644 src/tests/nativeaot/StartupHook/StartupHook.cs
 create mode 100644 src/tests/nativeaot/StartupHook/StartupHook.csproj

diff --git a/src/coreclr/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.xml b/src/coreclr/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.xml
index 7453ebc25a8f3..fb07d67f37c68 100644
--- a/src/coreclr/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.xml
+++ b/src/coreclr/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.xml
@@ -8,8 +8,5 @@
       <method signature="System.Boolean get_IsDynamicCodeCompiled()" body="stub" value="false" />
       <method signature="System.Boolean get_IsDynamicCodeSupported()" body="stub" value="false" />
     </type>
-    <type fullname="System.StartupHookProvider" feature="System.StartupHookProvider.IsSupported" featurevalue="false">
-      <method signature="System.Boolean get_IsSupported()" body="stub" value="false" />
-    </type>
   </assembly>
 </linker>
diff --git a/src/coreclr/nativeaot/System.Private.CoreLib/src/System.Private.CoreLib.csproj b/src/coreclr/nativeaot/System.Private.CoreLib/src/System.Private.CoreLib.csproj
index 2523a6d807201..1c24f9cc9c7be 100644
--- a/src/coreclr/nativeaot/System.Private.CoreLib/src/System.Private.CoreLib.csproj
+++ b/src/coreclr/nativeaot/System.Private.CoreLib/src/System.Private.CoreLib.csproj
@@ -221,6 +221,7 @@
     <Compile Include="System\String.Intern.cs" />
     <Compile Include="System\Array.NativeAot.cs" />
     <Compile Include="System\Delegate.cs" />
+    <Compile Include="System\StartupHookProvider.NativeAot.cs" />
     <Compile Include="System\RuntimeTypeHandle.cs" />
     <Compile Include="System\Exception.NativeAot.cs" />
     <Compile Include="System\RuntimeExceptionHelpers.cs" />
diff --git a/src/coreclr/nativeaot/System.Private.CoreLib/src/System/StartupHookProvider.NativeAot.cs b/src/coreclr/nativeaot/System.Private.CoreLib/src/System/StartupHookProvider.NativeAot.cs
new file mode 100644
index 0000000000000..07446c26310d7
--- /dev/null
+++ b/src/coreclr/nativeaot/System.Private.CoreLib/src/System/StartupHookProvider.NativeAot.cs
@@ -0,0 +1,19 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Runtime.CompilerServices;
+
+namespace System
+{
+    internal static partial class StartupHookProvider
+    {
+#pragma warning disable CA2255
+        [ModuleInitializer]
+#pragma warning restore CA2255
+        internal static void Initialize()
+        {
+            if (IsSupported)
+                ProcessStartupHooks(Environment.GetEnvironmentVariable("DOTNET_STARTUP_HOOKS"));
+        }
+    }
+}
diff --git a/src/coreclr/tools/aot/ILCompiler/repro/repro.csproj b/src/coreclr/tools/aot/ILCompiler/repro/repro.csproj
index 6dd2d0b010911..09e2a5bec4c8d 100644
--- a/src/coreclr/tools/aot/ILCompiler/repro/repro.csproj
+++ b/src/coreclr/tools/aot/ILCompiler/repro/repro.csproj
@@ -41,6 +41,7 @@
       <ReproResponseLines Include="--feature:System.Runtime.CompilerServices.RuntimeFeature.IsDynamicCodeSupported=false" />
       <ReproResponseLines Include="--feature:System.Globalization.Invariant=true" />
       <ReproResponseLines Include="--feature:System.Diagnostics.Debugger.IsSupported=false" />
+      <ReproResponseLines Include="--feature:System.StartupHookProvider.IsSupported=false" />
     </ItemGroup>
 
     <WriteLinesToFile File="$(OutputPath)\compile-with-$(LibrariesConfiguration)-libs.rsp"
diff --git a/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.Shared.xml b/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.Shared.xml
index 9765f3ab4f662..a152f063f51ce 100644
--- a/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.Shared.xml
+++ b/src/libraries/System.Private.CoreLib/src/ILLink/ILLink.Substitutions.Shared.xml
@@ -37,5 +37,8 @@
     <type fullname="Internal.Runtime.InteropServices.ComponentActivator" feature="System.Runtime.InteropServices.EnableConsumingManagedCodeFromNativeHosting" featurevalue="false">
       <method signature="System.Boolean get_IsSupported()" body="stub" value="false" />
     </type>
+    <type fullname="System.StartupHookProvider" feature="System.StartupHookProvider.IsSupported" featurevalue="false">
+      <method signature="System.Boolean get_IsSupported()" body="stub" value="false" />
+    </type>
   </assembly>
 </linker>
diff --git a/src/tests/nativeaot/StartupHook/StartupHook.cs b/src/tests/nativeaot/StartupHook/StartupHook.cs
new file mode 100644
index 0000000000000..ed85bdb060421
--- /dev/null
+++ b/src/tests/nativeaot/StartupHook/StartupHook.cs
@@ -0,0 +1,22 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Diagnostics.CodeAnalysis;
+
+class Program
+{
+    internal static int s_return;
+
+    [DynamicDependency(nameof(StartupHook.Initialize), typeof(StartupHook))]
+    static int Main() => s_return;
+}
+
+class StartupHook
+{
+    public static void Initialize()
+    {
+        Console.WriteLine("Running startup hook");
+        Program.s_return = 100;
+    }
+}
diff --git a/src/tests/nativeaot/StartupHook/StartupHook.csproj b/src/tests/nativeaot/StartupHook/StartupHook.csproj
new file mode 100644
index 0000000000000..f6b9b2ae9af15
--- /dev/null
+++ b/src/tests/nativeaot/StartupHook/StartupHook.csproj
@@ -0,0 +1,16 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <CLRTestPriority>0</CLRTestPriority>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <StartupHookSupport>true</StartupHookSupport>
+    <NoWarn>$(NoWarn);IL2026</NoWarn>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="StartupHook.cs" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <CLRTestEnvironmentVariable Include="DOTNET_STARTUP_HOOKS" Value="StartupHook" />
+  </ItemGroup>
+</Project>