Merge pull request #8733 from rolfbjarne/dotnet-linker

[dotnet] Add dotnet-linker, a project to contain custom linker steps for our net5.0 build.
2020-06-03 09:11:15 +02:00 · 2020-06-03 09:11:15 +02:00 · cb637a08a0
--- a/dotnet/targets/Xamarin.Shared.Sdk.targets
+++ b/dotnet/targets/Xamarin.Shared.Sdk.targets
@ -1,45 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
-	<Import Sdk="Microsoft.NET.Sdk" Project="Sdk.targets" />
-
-	<!-- Default item includes (globs and implicit references) -->
-	<Import Project="Xamarin.Shared.Sdk.DefaultItems.targets" />
-	<Import Project="Xamarin.Shared.Sdk.TargetFrameworkInference.targets" />
-
-	<!-- Inject our custom logic into *DependsOn variables -->
-	<PropertyGroup>
-		<BuildDependsOn>
-			$(BuildDependsOn);
-			_CreateAppBundle;
-		</BuildDependsOn>
-
-		<!-- We re-use ComputeFilesToPublish & CopyFilesToPublishDirectory to copy files to the .app -->
-		<CreateAppBundleDependsOn>
-			ComputeFilesToPublish;
-			_ComputePublishLocation;
-			CopyFilesToPublishDirectory;
-		</CreateAppBundleDependsOn>
-	</PropertyGroup>
-
-	<Target Name="_ComputePublishLocation" DependsOnTargets="_GenerateBundleName">
-		<!-- Put .dll, .pdb, .exe and .dylib in the .app -->
-		<PropertyGroup>
-			<_AssemblyPublishDir Condition="'$(_PlatformName)' != 'macOS'">$(MSBuildProjectDirectory)$(_AppBundlePath)\</_AssemblyPublishDir>
-			<_AssemblyPublishDir Condition="'$(_PlatformName)' == 'macOS'">$(MSBuildProjectDirectory)$(_AppBundlePath)\Contents\MonoBundle\</_AssemblyPublishDir>
-			<_DylibPublishDir Condition="'$(_PlatformName)' != 'macOS'">$(MSBuildProjectDirectory)$(_AppBundlePath)\</_DylibPublishDir>
-			<_DylibPublishDir Condition="'$(_PlatformName)' == 'macOS'">$(MSBuildProjectDirectory)$(_AppBundlePath)\Contents\MonoBundle\</_DylibPublishDir>
-		</PropertyGroup>
-		<ItemGroup>
-			<ResolvedFileToPublish
-				Update="@(ResolvedFileToPublish)"
-				RelativePath="$([MSBuild]::MakeRelative($(MSBuildProjectDirectory)$(PublishDir),$(_AssemblyPublishDir)))%(Filename)%(Extension)"
-				Condition="'%(Extension)' == '.dll' Or '%(Extension)' == '.pdb' Or '$(Extension)' == '.exe'" />
-			<ResolvedFileToPublish
-				Update="@(ResolvedFileToPublish)"
-				RelativePath="$([MSBuild]::MakeRelative($(MSBuildProjectDirectory)$(PublishDir),$(_DylibPublishDir)))%(Filename)%(Extension)"
-				Condition="'%(Extension)' == '.dylib'" />
-		</ItemGroup>
-	</Target>

 	<!-- Project types and how do we distinguish between them

@ -87,7 +47,77 @@
 		<_ProjectType Condition="'$(_ProjectType)' == '' And '$(_PlatformName)' == 'macOS' And '$(OutputType)' == 'Library' And '$(IsAppExtension)' != ''">macOSAppExtensionProject</_ProjectType>
 		<_ProjectType Condition="'$(_ProjectType)' == '' And '$(_PlatformName)' == 'macOS' And '$(OutputType)' == 'Library' And '$(IsBindingProject)' != ''">macOSBindingProject</_ProjectType>
 		<_ProjectType Condition="'$(_ProjectType)' == '' And '$(_PlatformName)' == 'macOS' And '$(OutputType)' == 'Library'">macOSClassLibrary</_ProjectType>
+	</PropertyGroup>

+	<PropertyGroup>
+		<!-- We must run the linker for executable projects and app extension projects. We must set PublishTrimmed before importing Microsoft.NET.Sdk, because it'll be evaluated there. -->
+		<PublishTrimmed Condition="'$(PublishTrimmed)' == '' And ($(_ProjectType.EndsWith ('ExecutableProject')) Or $(_ProjectType.EndsWith ('AppExtensionProject')))">true</PublishTrimmed>
+
+		<!-- App extensions are self-contained, even though their OutputType=Library -->
+		<SelfContained Condition="'$(SelfContained)' == '' And $(_ProjectType.EndsWith ('AppExtensionProject'))">true</SelfContained>
+	</PropertyGroup>
+
+	<Import Sdk="Microsoft.NET.Sdk" Project="Sdk.targets" />
+
+	<!-- Default item includes (globs and implicit references) -->
+	<Import Project="Xamarin.Shared.Sdk.DefaultItems.targets" />
+	<Import Project="Xamarin.Shared.Sdk.TargetFrameworkInference.targets" />
+
+	<!-- Inject our custom logic into *DependsOn variables -->
+	<PropertyGroup>
+		<BuildDependsOn>
+			$(BuildDependsOn);
+			_CreateAppBundle;
+		</BuildDependsOn>
+
+		<!-- We re-use ComputeFilesToPublish & CopyFilesToPublishDirectory to copy files to the .app -->
+		<!-- ComputeFilesToPublish will run ILLink -->
+		<CreateAppBundleDependsOn>
+			_ComputeLinkerArguments;
+			ComputeFilesToPublish;
+			_ComputePublishLocation;
+			CopyFilesToPublishDirectory;
+		</CreateAppBundleDependsOn>
+	</PropertyGroup>
+
+	<!-- Linker -->
+	<PropertyGroup>
+		<_AdditionalTaskAssemblyDirectory>$(_XamarinSdkRootDirectory)tools/dotnet-linker/</_AdditionalTaskAssemblyDirectory>
+		<_AdditionalTaskAssembly>$(_AdditionalTaskAssemblyDirectory)dotnet-linker.dll</_AdditionalTaskAssembly>
+	</PropertyGroup>
+	<Target Name="_ComputeLinkerArguments">
+		<ItemGroup>
+			<!-- add our custom steps -->
+			<_TrimmerCustomSteps Include="$(_AdditionalTaskAssembly)">
+				<BeforeStep>LoadReferencesStep</BeforeStep>
+				<Type>Xamarin.SetupStep</Type>
+			</_TrimmerCustomSteps>
+		</ItemGroup>
+	</Target>
+
+	<Target Name="_ComputePublishLocation" DependsOnTargets="_GenerateBundleName">
+		<!-- Put .dll, .pdb, .exe and .dylib in the .app -->
+		<PropertyGroup>
+			<_AssemblyPublishDir Condition="'$(_PlatformName)' != 'macOS'">$(MSBuildProjectDirectory)$(_AppBundlePath)\</_AssemblyPublishDir>
+			<_AssemblyPublishDir Condition="'$(_PlatformName)' == 'macOS'">$(MSBuildProjectDirectory)$(_AppBundlePath)\Contents\MonoBundle\</_AssemblyPublishDir>
+			<_DylibPublishDir Condition="'$(_PlatformName)' != 'macOS'">$(MSBuildProjectDirectory)$(_AppBundlePath)\</_DylibPublishDir>
+			<_DylibPublishDir Condition="'$(_PlatformName)' == 'macOS'">$(MSBuildProjectDirectory)$(_AppBundlePath)\Contents\MonoBundle\</_DylibPublishDir>
+		</PropertyGroup>
+		<ItemGroup>
+			<ResolvedFileToPublish
+				Update="@(ResolvedFileToPublish)"
+				RelativePath="$([MSBuild]::MakeRelative($(MSBuildProjectDirectory)$(PublishDir),$(_AssemblyPublishDir)))%(Filename)%(Extension)"
+				Condition="'%(Extension)' == '.dll' Or '%(Extension)' == '.pdb' Or '$(Extension)' == '.exe'" />
+			<ResolvedFileToPublish
+				Update="@(ResolvedFileToPublish)"
+				RelativePath="$([MSBuild]::MakeRelative($(MSBuildProjectDirectory)$(PublishDir),$(_DylibPublishDir)))%(Filename)%(Extension)"
+				Condition="'%(Extension)' == '.dylib'" />
+		</ItemGroup>
+	</Target>
+
+	<!-- Import existing targets -->
+
+	<PropertyGroup>
 		<_ProjectLanguage>$(Language)</_ProjectLanguage>
 		<_ProjectLanguage Condition="'$(_ProjectLanguage)' == '' Or '$(_ProjectLanguage)' == 'C#' ">CSharp</_ProjectLanguage>
 		<_ProjectLanguage Condition="'$(_ProjectLanguage)' == 'F#' ">FSharp</_ProjectLanguage>
@ -95,8 +125,6 @@
 		<_TargetsDirectory>$(_XamarinSdkRootDirectory)\tools\msbuild\$(_PlatformName)\</_TargetsDirectory>
 	</PropertyGroup>

-	<!-- Import existing targets -->
-
 	<Import Project="$(_TargetsDirectory)Xamarin.iOS.$(_ProjectLanguage).targets"                  Condition="'$(_ProjectType)' == 'iOSExecutableProject' Or '$(_ProjectType)' == 'iOSClassLibrary' " />
 	<Import Project="$(_TargetsDirectory)Xamarin.iOS.AppExtension.$(_ProjectLanguage).targets"     Condition="'$(_ProjectType)' == 'iOSAppExtensionProject' " />
 	<Import Project="$(_TargetsDirectory)Xamarin.iOS.ObjCBinding.$(_ProjectLanguage).targets"      Condition="'$(_ProjectType)' == 'iOSBindingProject' " />
--- a/tests/common/DotNet.cs
+++ b/tests/common/DotNet.cs
@ -24,12 +24,19 @@ namespace Xamarin.Tests {
 			}
 		}

-		public static void AssertBuild (string project, Dictionary<string, string> properties = null, string verbosity = "diagnostic")
+		public static ExecutionResult AssertBuild (string project, Dictionary<string, string> properties = null, string verbosity = "diagnostic")
 		{
-			Execute ("build", project, properties, out var _, verbosity, true);
+			return Execute ("build", project, properties, verbosity, true);
 		}

-		public static int Execute (string verb, string project, Dictionary<string, string> properties, out StringBuilder output, string verbosity = "diagnostic", bool assert_success = true)
+		public static ExecutionResult AssertBuildFailure (string project, Dictionary<string, string> properties = null, string verbosity = "diagnostic")
+		{
+			var rv = Execute ("build", project, properties, verbosity, false);
+			Assert.AreNotEqual (0, rv.ExitCode, "Unexpected success");
+			return rv;
+		}
+
+		public static ExecutionResult Execute (string verb, string project, Dictionary<string, string> properties, string verbosity = "diagnostic", bool assert_success = true)
 		{
 			if (!File.Exists (project))
 				throw new FileNotFoundException ($"The project file '{project}' does not exist.");
@ -51,7 +58,7 @@ namespace Xamarin.Tests {
 				var env = new Dictionary<string, string> ();
 				env ["MSBuildSDKsPath"] = null;
 				env ["MSBUILD_EXE_PATH"] = null;
-				output = new StringBuilder ();
+				var output = new StringBuilder ();
 				var rv = ExecutionHelper.Execute (Executable, args, env, output, output, workingDirectory: Path.GetDirectoryName (project), timeout: TimeSpan.FromMinutes (10));
 				if (rv != 0) {
 					Console.WriteLine ($"'{Executable} {StringUtils.FormatArguments (args)}' failed with exit code {rv}.");
@ -65,10 +72,21 @@ namespace Xamarin.Tests {
 						msg = "\n\t" + string.Join ("\n\t", errors);
 					Assert.AreEqual (0, rv, $"Exit code: {Executable} {StringUtils.FormatArguments (args)}{msg}");
 				}
-				return rv;
+				return new ExecutionResult {
+					StandardOutput = output,
+					StandardError = output,
+					ExitCode = rv,
+				};
 			default:
 				throw new NotImplementedException ($"Unknown dotnet action: '{verb}'");
 			}
 		}
 	}
+
+	public class ExecutionResult {
+		public StringBuilder StandardOutput;
+		public StringBuilder StandardError;
+		public int ExitCode;
+		public bool TimedOut;
+	}
 }
--- a/tests/dotnet/UnitTests/ProjectTest.cs
+++ b/tests/dotnet/UnitTests/ProjectTest.cs
@ -5,7 +5,7 @@ using NUnit.Framework;
 namespace Xamarin.Tests {
 	[TestFixture]
 	public class DotNetProjectTest {
-		void Build (string project, string subdir = null)
+		string GetProjectPath (string project, string subdir = null)
 		{
 			var project_dir = Path.Combine (Configuration.SourceRoot, "tests", "dotnet", project);
 			if (!string.IsNullOrEmpty (subdir))
@ -15,31 +15,57 @@ namespace Xamarin.Tests {
 			if (!File.Exists (project_path))
 				project_path = Path.ChangeExtension (project_path, "sln");

-			DotNet.AssertBuild (project_path);
+			if (!File.Exists (project_path))
+				throw new FileNotFoundException ($"Could not find the project or solution {project}");
+
+			return project_path;
+		}
+
+		void Clean (string project_path)
+		{
+			var dirs = Directory.GetDirectories (Path.GetDirectoryName (project_path), "*", SearchOption.AllDirectories);
+			foreach (var dir in dirs) {
+				var name = Path.GetFileName (dir);
+				if (name != "bin" && name != "obj")
+					continue;
+				Directory.Delete (dir, true);
+			}
 		}

 		[Test]
 		public void BuildMySingleView ()
 		{
-			Build ("MySingleView");
+			var project_path = GetProjectPath ("MySingleView");
+			Clean (project_path);
+			var result = DotNet.AssertBuild (project_path);
+			AssertThatLinkerExecuted (result);
 		}

 		[Test]
 		public void BuildMyCocoaApp ()
 		{
-			Build ("MyCocoaApp");
+			var project_path = GetProjectPath ("MyCocoaApp");
+			Clean (project_path);
+			var result = DotNet.AssertBuild (project_path);
+			AssertThatLinkerExecuted (result);
 		}

 		[Test]
 		public void BuildMyTVApp ()
 		{
-			Build ("MyTVApp");
+			var project_path = GetProjectPath ("MyTVApp");
+			Clean (project_path);
+			var result = DotNet.AssertBuild (project_path);
+			AssertThatLinkerExecuted (result);
 		}

 		[Test]
 		public void BuildMyWatchApp ()
 		{
-			Build ("MyWatchApp");
+			var project_path = GetProjectPath ("MyWatchApp");
+			Clean (project_path);
+			var result = DotNet.AssertBuildFailure (project_path);
+			Assert.That (result.StandardOutput.ToString (), Does.Contain ("The specified RuntimeIdentifier 'watchos-x86' is not recognized."), "Missing runtime pack for watchOS");
 		}

 		[TestCase ("iOS")]
@ -48,7 +74,17 @@ namespace Xamarin.Tests {
 		[TestCase ("macOS")]
 		public void BuildMyClassLibrary (string platform)
 		{
-			Build ("MyClassLibrary", platform);
+			var project_path = GetProjectPath ("MyClassLibrary", platform);
+			Clean (project_path);
+			var result = DotNet.AssertBuild (project_path);
+			Assert.That (result.StandardOutput.ToString (), Does.Not.Contain ("Task \"ILLink\""), "Linker executed unexpectedly.");
+		}
+
+		void AssertThatLinkerExecuted (ExecutionResult result)
+		{
+			var output = result.StandardOutput.ToString ();
+			Assert.That (output, Does.Contain ("Building target \"_RunILLink\" completely."), "Linker did not executed as expected.");
+			Assert.That (output, Does.Contain ("Hello SetupStep"), "Custom steps did not run as expected.");
 		}
 	}
 }
--- a/tools/Makefile
+++ b/tools/Makefile
@ -1,3 +1,3 @@
 TOP=..
-SUBDIRS=mmp mtouch install-source xibuild mlaunch siminstaller
+SUBDIRS=mmp mtouch install-source xibuild mlaunch siminstaller dotnet-linker
 include $(TOP)/Make.config
--- a/tools/common/create-makefile-fragment.sh
+++ b/tools/common/create-makefile-fragment.sh
@ -27,17 +27,26 @@ PROJECT_FILE="$1"
 PROJECT=$(basename -s .csproj "$PROJECT_FILE")
 PROJECT_DIR=$(dirname "$PROJECT_FILE")
 FRAGMENT_PATH="$2"
-REFERENCES_PATH=$PROJECT-references.txt
+REFERENCES_PATH=$(pwd)/$PROJECT-references.txt

 if test -z "$FRAGMENT_PATH"; then
 	FRAGMENT_PATH=$PROJECT_FILE.inc
 fi

+if test -z "$BUILD_EXECUTABLE"; then
+	BUILD_EXECUTABLE=msbuild
+fi
+
 # ProjectInspector.csproj is an MSBuild file with a target
 # (WriteProjectReferences) that takes another project file as input (the
 # ProjectFile variable) and writes all the project references (recursively) to
 # a file (the ReferenceListPath variable).
-msbuild ProjectInspector.csproj "/t:WriteProjectReferences" "/p:ProjectFile=$PROJECT_FILE" "/p:ReferenceListPath=$REFERENCES_PATH" /verbosity:quiet /nologo
+(
+cp ProjectInspector.csproj "$PROJECT_DIR"
+cd "$PROJECT_DIR"
+$BUILD_EXECUTABLE ProjectInspector.csproj "/t:WriteProjectReferences" "/p:ProjectFile=$PROJECT_FILE" "/p:ReferenceListPath=$REFERENCES_PATH" /verbosity:quiet /nologo
+rm -f ProjectInspector.csproj
+)

 # Now we have a list of all the project referenced by the input project. The
 # ProjectInspector.csproj also has a target (WriteInputs) that can list all
@ -79,7 +88,11 @@ for proj in $(sort "$REFERENCES_PATH" | uniq); do
 	proj_dir=$(dirname "$proj")
 	inputs_path=$PWD/$proj_name.inputs
 	INPUT_PATHS+=("$inputs_path")
-	msbuild "$TMPPROJ" "/t:WriteInputs" "/p:ProjectFile=$proj" "/p:InputsPath=$inputs_path" /verbosity:quiet /nologo
+
+	(
+	cd "$(dirname "$proj")"
+	$BUILD_EXECUTABLE "$TMPPROJ" "/t:WriteInputs" "/p:ProjectFile=$proj" "/p:InputsPath=$inputs_path" /verbosity:quiet /nologo
+	)

 	# The output contains relative paths, relative to the csproj directory
 	# Change those to full paths by prepending the csproj directory.
@ -99,7 +112,7 @@ done
 # First add a dependency for the csproj.inc so that it's rebuilt if the project itself changes.
 echo "${PROJECT}.csproj.inc: ${PROJECT_FILE} $PWD/ProjectInspector.csproj" > "$FRAGMENT_PATH"
 # Now create the variable with all the input files.
-echo "${PROJECT}_dependencies = \\" >> "$FRAGMENT_PATH"
+echo "${PROJECT//-/_}_dependencies = \\" >> "$FRAGMENT_PATH"
 sort "${INPUT_PATHS[@]}" | uniq >> "$FRAGMENT_PATH"

 # Simplify paths somewhat by removing the current directory
--- a/tools/dotnet-linker/.gitignore
+++ b/tools/dotnet-linker/.gitignore
@ -0,0 +1,2 @@
+*.csproj.inc
+.vscode/
--- a/tools/dotnet-linker/Makefile
+++ b/tools/dotnet-linker/Makefile
@ -0,0 +1,42 @@
+TOP=../..
+
+include $(TOP)/Make.config
+
+PLATFORMS=iOS tvOS watchOS macOS
+
+BUILD_DIR=bin/Debug/net5.0
+
+DOTNET_TARGETS += \
+	$(BUILD_DIR)/dotnet-linker.dll \
+	$(foreach platform,$(PLATFORMS),$(DOTNET_DESTDIR)/Microsoft.$(platform).Sdk/tools/dotnet-linker/dotnet-linker.dll) \
+	$(foreach platform,$(PLATFORMS),$(DOTNET_DESTDIR)/Microsoft.$(platform).Sdk/tools/dotnet-linker/dotnet-linker.pdb) \
+
+DOTNET_DIRECTORIES += \
+	$(foreach platform,$(PLATFORMS),$(DOTNET_DESTDIR)/Microsoft.$(platform).Sdk/tools/dotnet-linker) \
+
+$(BUILD_DIR)/dotnet-linker%dll $(BUILD_DIR)/dotnet-linker%pdb: Makefile $(dotnet_linker_dependencies)
+	$(Q_DOTNET_BUILD) $(DOTNET5) build $(XBUILD_VERBOSITY)
+
+$(DOTNET_DESTDIR)/Microsoft.iOS.Sdk/tools/dotnet-linker/%: $(BUILD_DIR)/% | $(DOTNET_DESTDIR)/Microsoft.iOS.Sdk/tools/dotnet-linker
+	$(Q) $(CP) $< $@
+
+$(DOTNET_DESTDIR)/Microsoft.tvOS.Sdk/tools/dotnet-linker/%: $(BUILD_DIR)/% | $(DOTNET_DESTDIR)/Microsoft.tvOS.Sdk/tools/dotnet-linker
+	$(Q) $(CP) $< $@
+
+$(DOTNET_DESTDIR)/Microsoft.watchOS.Sdk/tools/dotnet-linker/%: $(BUILD_DIR)/% | $(DOTNET_DESTDIR)/Microsoft.watchOS.Sdk/tools/dotnet-linker
+	$(Q) $(CP) $< $@
+
+$(DOTNET_DESTDIR)/Microsoft.macOS.Sdk/tools/dotnet-linker/%: $(BUILD_DIR)/% | $(DOTNET_DESTDIR)/Microsoft.macOS.Sdk/tools/dotnet-linker
+	$(Q) $(CP) $< $@
+
+$(DOTNET_DIRECTORIES):
+	$(Q) mkdir -p $@
+
+# dotnet-linker.csproj.inc contains the dotnet_linker_dependencies variable used to determine if mtouch needs to be rebuilt or not.
+dotnet-linker.csproj.inc: export BUILD_EXECUTABLE=$(DOTNET5) build
+dotnet-linker.csproj.inc: dotnet-linker.csproj Makefile ../common/create-makefile-fragment.sh $(TOP)/Make.config $(TOP)/mk/mono.mk
+	$(Q_GEN) ../common/create-makefile-fragment.sh $(abspath $<)
+-include dotnet-linker.csproj.inc
+
+all-local:: $(DOTNET_TARGETS)
+install-local:: $(DOTNET_TARGETS)
--- a/tools/dotnet-linker/NuGet.config
+++ b/tools/dotnet-linker/NuGet.config
@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+	<config>
+		<add key="repositorypath" value="packages" />
+		<add key="globalPackagesFolder" value="packages" />
+	</config>
+	<packageSources>
+		<add key="Nuget Official" value="https://www.nuget.org/api/v2/" />
+		<add key="Dotnet arcade" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-eng/nuget/v3/index.json" />
+		<add key="dotnet5" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet5/nuget/v3/index.json" />
+	</packageSources>
+</configuration>
+
--- a/tools/dotnet-linker/README.md
+++ b/tools/dotnet-linker/README.md
@ -0,0 +1,7 @@
+# Linker
+
+This directory contains the custom linker steps for the managed linker when
+building Xamarin.iOS/tvOS/watchOS/macOS apps using .NET 5.
+
+This is work in progress, and is not in a releasable state yet.
+
--- a/tools/dotnet-linker/SetupStep.cs
+++ b/tools/dotnet-linker/SetupStep.cs
@ -0,0 +1,15 @@
+using System;
+
+using Mono.Linker.Steps;
+
+namespace Xamarin {
+
+	public class SetupStep : BaseStep {
+
+		protected override void Process ()
+		{
+			// This will be replaced with something more useful later.
+			Console.WriteLine ("Hello SetupStep");
+		}
+	}
+}
--- a/tools/dotnet-linker/dotnet-linker.csproj
+++ b/tools/dotnet-linker/dotnet-linker.csproj
@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net5.0</TargetFramework>
+    <RootNamespace>dotnet_linker</RootNamespace>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.ILLink" Version="5.0.0-preview.3.20302.1" />
+  </ItemGroup>
+</Project>
--- a/tools/dotnet-linker/dotnet-linker.sln
+++ b/tools/dotnet-linker/dotnet-linker.sln
@ -0,0 +1,17 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 15
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "dotnet-linker", "dotnet-linker.csproj", "{7F7392F4-AB2D-4153-B591-46C79501B3C6}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{7F7392F4-AB2D-4153-B591-46C79501B3C6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{7F7392F4-AB2D-4153-B591-46C79501B3C6}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{7F7392F4-AB2D-4153-B591-46C79501B3C6}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{7F7392F4-AB2D-4153-B591-46C79501B3C6}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+EndGlobal
--- a/tools/dotnet-linker/global.json
+++ b/tools/dotnet-linker/global.json
@ -0,0 +1,3 @@
+{
+	"sdk": { "version": "5.*" }
+}