[dotnet] Turn class-redirector into a Task

tools/class-redirector/class-redirector/ClassRedirectorTask.cs

@@ -0,0 +1,95 @@
+using System;
+using System.Xml.Linq;
+using Microsoft.Build.Framework;
+using Microsoft.Build.Utilities;
+
+#nullable enable
+
+namespace ClassRedirector
+{
+	public class ClassRedirectorTask : Microsoft.Build.Utilities.Task
+	{
+		public override bool Execute ()
+		{
+			if (!Directory.Exists (InputDirectory)) {
+				Log.LogError ($"InputDirectory {InputDirectory} doesn't exist.");
+				return false;
+			}
+
+			if (!DirectoryIsWritable (InputDirectory)) {
+				Log.LogError ($"InputDirectory {InputDirectory} is not writable.");
+				return false;
+			}
+
+			if (!File.Exists (ClassMapPath)) {
+				Log.LogError ($"ClassMapPath file {ClassMapPath} does not exist.");
+				return false;
+			}
+
+			var dllsToProcess = CollectDlls (InputDirectory);
+			var xamarinDll = FindXamarinDll (dllsToProcess);
+
+			if (xamarinDll is null) {
+				Log.LogError ($"unable to find platform dll in {InputDirectory}");
+				return false;
+			}
+
+			var map = ReadRegistrarFile (ClassMapPath);
+
+			try {
+				Log.LogMessage ($"Redirecting class_handle usage from directory {InputDirectory} in the following dlls: {string.Join (",", dllsToProcess)}");
+				Log.LogMessage ($"Redirecting class_handle usage with the platform dll {xamarinDll}");
+				Log.LogMessage ($"Redirecting class_handle usage with the following {nameof (ClassMapPath)}: {ClassMapPath}");
+				var rewriter = new Rewriter (map, xamarinDll, dllsToProcess);
+				rewriter.Process ();
+			} catch (Exception e) {
+				Log.LogErrorFromException (e);
+			}
+
+			return true;
+		}
+
+		[Required]
+		public string InputDirectory { get; set; } = "";
+
+		[Required]
+		public string ClassMapPath { get; set; } = "";
+
+		static bool DirectoryIsWritable (string path)
+		{
+			var info = new DirectoryInfo (path);
+			return !info.Attributes.HasFlag (FileAttributes.ReadOnly);
+		}
+
+		static string [] CollectDlls (string dir)
+		{
+			return Directory.GetFiles (dir, "*.dll"); // GetFiles returns full paths
+		}
+
+		static string [] xamarinDlls = new string [] {
+			"Microsoft.iOS.dll",
+			"Microsoft.macOS.dll",
+			"Microsoft.tvOS.dll",
+		};
+
+		static bool IsXamarinDll (string p)
+		{
+			return xamarinDlls.FirstOrDefault (dll => p.EndsWith (dll, StringComparison.Ordinal)) is not null;
+		}
+
+		static string? FindXamarinDll (string [] paths)
+		{
+			return paths.FirstOrDefault (IsXamarinDll);
+		}
+
+		static CSToObjCMap ReadRegistrarFile (string path)
+		{
+			var doc = XDocument.Load (path);
+			var map = CSToObjCMap.FromXDocument (doc);
+			if (map is null)
+				throw new Exception ($"Unable to read static registrar map file {path}");
+			return map;
+		}
+	}
+}
+

tools/class-redirector/class-redirector/class-redirector.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <OutputType>Exe</OutputType>
+    <OutputType>Library</OutputType>
     <TargetFramework>net7.0</TargetFramework>
     <RootNamespace>class_redirector</RootNamespace>
     <ImplicitUsings>enable</ImplicitUsings>
@@ -11,6 +11,7 @@
   <ItemGroup>
     <PackageReference Include="Mono.Cecil" Version="0.11.4" />
     <PackageReference Include="Mono.Options" Version="6.12.0.148" />
+    <PackageReference Include="Microsoft.Build.Utilities.Core" Version="17.5.0" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="..\..\common\CSToObjCMap.cs">