[dotnet-linker] Add OptimizeGeneratedCodeSubStep into the pipeline. (#9608)

Fixes these linkall tests:

    Linker.Shared.OptimizeGeneratedCodeTest
        [FAIL] IsARM64CallingConvention :   optimized: no ldsfld instruction
        Expected: 0
        But was:  1
            at Linker.Shared.BaseOptimizeGeneratedCodeTest.IsARM64CallingConvention() in /Users/rolf/work/maccore/main/xamarin-macios/tests/linker/BaseOptimizeGeneratedCodeTest.cs:line 527
    
    [FAIL] SetupBlockPerfTest :   At least 6x speedup
        Expected: greater than 6
        But was:  1.0876440665344851d
            at Linker.Shared.BaseOptimizeGeneratedCodeTest.SetupBlockPerfTest() in /Users/rolf/work/maccore/main/xamarin-macios/tests/linker/BaseOptimizeGeneratedCodeTest.cs:line 120

And linkall is now green for .NET/Debug.

tests/xharness/Harness.cs

@@ -395,7 +395,7 @@ namespace Xharness {
 			IOSTestProjects.Add (new iOSTestProject (Path.GetFullPath (Path.Combine (RootDirectory, "linker", "ios", "dont link", "dont link.csproj"))) { Configurations = new string [] { "Debug", "Release" } });
 			IOSTestProjects.Add (new iOSTestProject (Path.GetFullPath (Path.Combine (RootDirectory, "linker", "ios", "dont link", "dotnet", "iOS", "dont link.csproj"))) { Configurations = new string [] { "Debug", "Release" }, IsDotNetProject = true, SkipiOSVariation = false, SkiptvOSVariation = true, SkipwatchOSVariation = true, SkipTodayExtensionVariation = true, SkipDeviceVariations = true, SkipiOS32Variation = true });
 			IOSTestProjects.Add (new iOSTestProject (Path.GetFullPath (Path.Combine (RootDirectory, "linker", "ios", "link all", "link all.csproj"))) { Configurations = new string [] { "Debug", "Release" } });
-			IOSTestProjects.Add (new iOSTestProject (Path.GetFullPath (Path.Combine (RootDirectory, "linker", "ios", "link all", "dotnet", "iOS", "link all.csproj"))) { Configurations = new string [] { "Debug", "Release" }, IsDotNetProject = true, SkipiOSVariation = false, SkiptvOSVariation = true, SkipwatchOSVariation = true, SkipTodayExtensionVariation = true, SkipDeviceVariations = true, SkipiOS32Variation = true, Ignore = true });
+			IOSTestProjects.Add (new iOSTestProject (Path.GetFullPath (Path.Combine (RootDirectory, "linker", "ios", "link all", "dotnet", "iOS", "link all.csproj"))) { Configurations = new string [] { "Debug" /*, "Release" */ }, IsDotNetProject = true, SkipiOSVariation = false, SkiptvOSVariation = true, SkipwatchOSVariation = true, SkipTodayExtensionVariation = true, SkipDeviceVariations = true, SkipiOS32Variation = true });
 			IOSTestProjects.Add (new iOSTestProject (Path.GetFullPath (Path.Combine (RootDirectory, "linker", "ios", "link sdk", "link sdk.csproj"))) { Configurations = new string [] { "Debug", "Release" } });
 			IOSTestProjects.Add (new iOSTestProject (Path.GetFullPath (Path.Combine (RootDirectory, "linker", "ios", "link sdk", "dotnet", "iOS", "link sdk.csproj"))) { Configurations = new string [] { "Debug" /*, "Release" */ }, IsDotNetProject = true, SkipiOSVariation = false, SkiptvOSVariation = true, SkipwatchOSVariation = true, SkipTodayExtensionVariation = true, SkipDeviceVariations = true, SkipiOS32Variation = true });
 

tools/common/Application.cs

@@ -707,6 +707,7 @@ namespace Xamarin.Bundler {
 
 		public IEnumerable<Abi> Abis {
 			get { return abis; }
+			set { abis = new List<Abi> (value); }
 		}
 
 		public bool IsArchEnabled (Abi arch)

tools/dotnet-linker/Compat.cs

@@ -1,6 +1,7 @@
 // Compat.cs: might not be ideal but it eases code sharing with existing code during the initial implementation.
 using System;
 using System.Collections.Generic;
+using System.Runtime.CompilerServices;
 
 using Mono.Cecil;
 using Mono.Linker;
@@ -160,9 +161,14 @@ namespace Mono.Linker {
 		{
 			return LinkerConfiguration.GetInstance (context).Assemblies;
 		}
+
+		static ConditionalWeakTable<AnnotationStore, Dictionary<string, Dictionary<IMetadataTokenProvider, object>>> custom_annotations = new ConditionalWeakTable<AnnotationStore, Dictionary<string, Dictionary<IMetadataTokenProvider, object>>> ();
 		public static Dictionary<IMetadataTokenProvider, object> GetCustomAnnotations (this AnnotationStore self, string name)
 		{
-			throw new NotImplementedException ();
+			var store = custom_annotations.GetOrCreateValue (self);
+			if (!store.TryGetValue (name, out var dict))
+				store [name] = dict = new Dictionary<IMetadataTokenProvider, object> ();
+			return dict;
 		}
 	}
 }

tools/dotnet-linker/LinkerConfiguration.cs

@@ -208,6 +208,10 @@ namespace Xamarin.Linker {
 			Application.DeploymentTarget = DeploymentTarget;
 			Application.SdkVersion = SdkVersion;
 
+			DerivedLinkContext.Target = Target;
+			Target.Abis = Abis;
+			Application.Abis = Abis;
+
 			switch (Platform) {
 			case ApplePlatform.iOS:
 			case ApplePlatform.TVOS:

tools/dotnet-linker/SetupStep.cs

@@ -55,6 +55,7 @@ namespace Xamarin {
 				// [assembly: LinkSafe] attributes, which means we treat them as sdk assemblies and those may have
 				// Preserve attributes.
 				prelink_substeps.Add (new ApplyPreserveAttribute ());
+				prelink_substeps.Add (new OptimizeGeneratedCodeSubStep ());
 				prelink_substeps.Add (new MarkNSObjects ());
 				prelink_substeps.Add (new PreserveSmartEnumConversionsSubStep ());
 			}

tools/dotnet-linker/dotnet-linker.csproj

@@ -101,6 +101,9 @@
     <Compile Include="..\linker\CustomSymbolWriter.cs">
       <Link>external\tools\linker\CustomSymbolWriter.cs</Link>
     </Compile>
+    <Compile Include="..\linker\CoreOptimizeGeneratedCode.cs">
+      <Link>external\tools\linker\CoreOptimizeGeneratedCode.cs</Link>
+    </Compile>
     <Compile Include="..\..\src\ObjCRuntime\Registrar.cs">
       <Link>external\src\ObjCRuntime\Registrar.cs</Link>
     </Compile>
@@ -164,6 +167,12 @@
     <Compile Include="..\..\builds\mono-ios-sdk-destdir\ios-sources\external\linker\src\linker\Linker\I18nAssemblies.cs">
       <Link>external\mono-archive\Linker\I18nAssemblies.cs</Link>
     </Compile>
+    <Compile Include="..\..\builds\mono-ios-sdk-destdir\ios-sources\external\linker\src\linker\Linker\MethodDefinitionExtensions.cs">
+      <Link>mono-archive\Linker\MethodDefinitionExtensions.cs</Link>
+    </Compile>
+    <Compile Include="..\..\builds\mono-ios-sdk-destdir\ios-sources\external\linker\src\linker\Linker\TypeReferenceExtensions.cs">
+      <Link>mono-archive\Linker\Linker\TypeReferenceExtensions.cs</Link>
+    </Compile>
     <Compile Include="..\..\builds\mono-ios-sdk-destdir\ios-sources\external\linker\src\tuner\Mono.Tuner\CecilRocks.cs">
       <Link>external\mono-archive\Mono.Tuner\CecilRocks.cs</Link>
     </Compile>

tools/linker/CoreOptimizeGeneratedCode.cs

@@ -573,7 +573,7 @@ namespace Xamarin.Linker {
 					}
 				}
 			}
-#if TRACE
+#if false
 			Console.WriteLine ($"{caller.FullName}:");
 			for (int i = 0; i < reachable.Length; i++) {
 				Console.WriteLine ($"{(reachable [i] ? "   " : "-  ")} {instructions [i]}");