[wasm] Build tasks for net472 also

src/mono/nuget/Microsoft.NET.Runtime.MonoAOTCompiler.Task/Sdk/Sdk.props

@@ -1,6 +1,7 @@
 <Project>
   <PropertyGroup>
-    <MonoAOTCompilerTasksAssemblyPath>$(MSBuildThisFileDirectory)..\tasks\MonoAOTCompiler.dll</MonoAOTCompilerTasksAssemblyPath>
+    <MonoAOTCompilerTasksAssemblyPath Condition="'$(MSBuildRuntimeType)' == 'Core'">$(MSBuildThisFileDirectory)..\tasks\net6.0\MonoAOTCompiler.dll</MonoAOTCompilerTasksAssemblyPath>
+    <MonoAOTCompilerTasksAssemblyPath Condition="'$(MSBuildRuntimeType)' != 'Core'">$(MSBuildThisFileDirectory)..\tasks\net472\MonoAOTCompiler.dll</MonoAOTCompilerTasksAssemblyPath>
   </PropertyGroup>
   <UsingTask TaskName="MonoAOTCompiler" AssemblyFile="$(MonoAOTCompilerTasksAssemblyPath)" />
 </Project>

src/mono/nuget/Microsoft.NET.Runtime.WebAssembly.Sdk/Sdk/Sdk.targets

@@ -1,8 +1,11 @@
 <Project>
   <!-- Property overrides -->
   <PropertyGroup>
-    <WasmAppBuilderTasksAssemblyPath>$(MSBuildThisFileDirectory)..\tasks\WasmAppBuilder.dll</WasmAppBuilderTasksAssemblyPath>
-    <WasmBuildTasksAssemblyPath>$(MSBuildThisFileDirectory)..\tasks\WasmBuildTasks.dll</WasmBuildTasksAssemblyPath>
+    <_TasksDir Condition="'$(MSBuildRuntimeType)' == 'Core'">$(MSBuildThisFileDirectory)..\tasks\net6.0\</_TasksDir>
+    <_TasksDir Condition="'$(MSBuildRuntimeType)' != 'Core'">$(MSBuildThisFileDirectory)..\tasks\net472\</_TasksDir>
+
+    <WasmAppBuilderTasksAssemblyPath>$(_TasksDir)WasmAppBuilder.dll</WasmAppBuilderTasksAssemblyPath>
+    <WasmBuildTasksAssemblyPath>$(_TasksDir)WasmBuildTasks.dll</WasmBuildTasksAssemblyPath>
   </PropertyGroup>
 
   <Import Project="$(MSBuildThisFileDirectory)\WasmApp.props" />

src/tasks/AotCompilerTask/MonoAOTCompiler.cs

@@ -190,7 +190,7 @@ public override bool Execute()
 
         if (!Enum.TryParse(Mode, true, out parsedAotMode))
         {
-            Log.LogError($"Unknown Mode value: {Mode}. '{nameof(Mode)}' must be one of: {string.Join(',', Enum.GetNames(typeof(MonoAotMode)))}");
+            Log.LogError($"Unknown Mode value: {Mode}. '{nameof(Mode)}' must be one of: {string.Join(",", Enum.GetNames(typeof(MonoAotMode)))}");
             return false;
         }
 
@@ -222,7 +222,7 @@ public override bool Execute()
 
         string? monoPaths = null;
         if (AdditionalAssemblySearchPaths != null)
-            monoPaths = string.Join(Path.PathSeparator, AdditionalAssemblySearchPaths);
+            monoPaths = string.Join(Path.PathSeparator.ToString(), AdditionalAssemblySearchPaths);
 
         if (DisableParallelAot)
         {
@@ -257,13 +257,13 @@ private bool PrecompileLibrary(ITaskItem assemblyItem, string? monoPaths)
         var a = assemblyItem.GetMetadata("AotArguments");
         if (a != null)
         {
-             aotArgs.AddRange(a.Split(";", StringSplitOptions.RemoveEmptyEntries));
+             aotArgs.AddRange(a.Split(new char[]{ ';' }, StringSplitOptions.RemoveEmptyEntries));
         }
 
         var p = assemblyItem.GetMetadata("ProcessArguments");
         if (p != null)
         {
-            processArgs.AddRange(p.Split(";", StringSplitOptions.RemoveEmptyEntries));
+            processArgs.AddRange(p.Split(new char[]{ ';' }, StringSplitOptions.RemoveEmptyEntries));
         }
 
         Log.LogMessage(MessageImportance.Low, $"[AOT] {assembly}");

src/tasks/AotCompilerTask/MonoAOTCompiler.csproj

@@ -1,11 +1,14 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>$(NetCoreAppToolCurrent)</TargetFramework>
+    <TargetFrameworks>$(NetCoreAppToolCurrent);net472</TargetFrameworks>
     <OutputType>Library</OutputType>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <EnableDefaultCompileItems>false</EnableDefaultCompileItems>
     <Nullable>enable</Nullable>
     <NoWarn>$(NoWarn),CA1050</NoWarn>
+
+    <!-- Ignore nullable warnings on net4* -->
+    <NoWarn Condition="$(TargetFramework.StartsWith('net4'))">$(NoWarn),CS8604,CS8602</NoWarn>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Microsoft.Build" Version="$(RefOnlyMicrosoftBuildVersion)" />
@@ -16,6 +19,7 @@
   <ItemGroup>
     <Compile Include="MonoAOTCompiler.cs" />
     <Compile Include="..\Common\Utils.cs" />
+    <Compile Include="..\Common\NotNullAttribute.cs" Condition="$(TargetFramework.StartsWith('net4'))" />
   </ItemGroup>
   <ItemGroup>
     <Content Include="MonoAOTCompiler.props">
@@ -26,7 +30,10 @@
   <!-- GetFilesToPackage assists to place `MonoAOTCompiler.dll` in a NuGet package in Microsoft.NET.Runtime.MonoAOTCompiler.Task.pkgproj for external use -->
   <Target Name="GetFilesToPackage" Returns="@(FilesToPackage)">
     <ItemGroup>
-      <FilesToPackage Include="$(OutputPath)$(AssemblyName).dll" TargetPath="tasks" />
+      <_PublishFramework Remove="@(_PublishFramework)" />
+      <_PublishFramework Include="$(TargetFrameworks)" />
+
+      <FilesToPackage Include="$(OutputPath)%(_PublishFramework.Identity)\$(AssemblyName).dll" TargetPath="tasks\%(_PublishFramework.Identity)" />
     </ItemGroup>
   </Target>
 </Project>

src/tasks/Common/NotNullAttribute.cs

@@ -0,0 +1,7 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+[System.AttributeUsage(System.AttributeTargets.Field | System.AttributeTargets.Parameter | System.AttributeTargets.Property | System.AttributeTargets.ReturnValue, Inherited=false)]
+public sealed class NotNullAttribute : System.Attribute
+{
+}

src/tasks/Common/Utils.cs

@@ -102,6 +102,7 @@ public static string RunProcess(
         return outputBuilder.ToString().Trim('\r', '\n');
     }
 
+#if NETCOREAPP
     public static void DirectoryCopy(string sourceDir, string destDir, Func<string, bool> predicate)
     {
         string[] files = Directory.GetFiles(sourceDir, "*", SearchOption.AllDirectories);
@@ -118,6 +119,7 @@ public static void DirectoryCopy(string sourceDir, string destDir, Func<string,
             File.Copy(file, Path.Combine(destDir, relativePath), true);
         }
     }
+#endif
 
     public static TaskLoggingHelper? Logger { get; set; }
 

src/tasks/WasmAppBuilder/WasmAppBuilder.cs

@@ -86,9 +86,9 @@ protected AssetEntry (string name, string behavior)
             Behavior = behavior;
         }
         [JsonPropertyName("behavior")]
-        public string Behavior { get; init; }
+        public string Behavior { get; set; }
         [JsonPropertyName("name")]
-        public string Name { get; init; }
+        public string Name { get; set; }
     }
 
     private class AssemblyEntry : AssetEntry
@@ -144,18 +144,18 @@ public override bool Execute ()
         var config = new WasmAppConfig ();
 
         // Create app
-        var asmRootPath = Path.Join(AppDir, config.AssemblyRoot);
+        var asmRootPath = Path.Combine(AppDir, config.AssemblyRoot);
         Directory.CreateDirectory(AppDir!);
         Directory.CreateDirectory(asmRootPath);
         foreach (var assembly in _assemblies)
         {
-            FileCopyChecked(assembly, Path.Join(asmRootPath, Path.GetFileName(assembly)), "Assemblies");
+            FileCopyChecked(assembly, Path.Combine(asmRootPath, Path.GetFileName(assembly)), "Assemblies");
             if (DebugLevel != 0)
             {
                 var pdb = assembly;
                 pdb = Path.ChangeExtension(pdb, ".pdb");
                 if (File.Exists(pdb))
-                    FileCopyChecked(pdb, Path.Join(asmRootPath, Path.GetFileName(pdb)), "Assemblies");
+                    FileCopyChecked(pdb, Path.Combine(asmRootPath, Path.GetFileName(pdb)), "Assemblies");
             }
         }
 
@@ -165,10 +165,10 @@ public override bool Execute ()
             if (!FileCopyChecked(item.ItemSpec, dest, "NativeAssets"))
                 return false;
         }
-        FileCopyChecked(MainJS!, Path.Join(AppDir, "runtime.js"), string.Empty);
+        FileCopyChecked(MainJS!, Path.Combine(AppDir, "runtime.js"), string.Empty);
 
         var html = @"<html><body><script type=""text/javascript"" src=""runtime.js""></script></body></html>";
-        File.WriteAllText(Path.Join(AppDir, "index.html"), html);
+        File.WriteAllText(Path.Combine(AppDir, "index.html"), html);
 
         foreach (var assembly in _assemblies)
         {
@@ -190,16 +190,16 @@ public override bool Execute ()
                 string culture = assembly.GetMetadata("CultureName") ?? string.Empty;
                 string fullPath = assembly.GetMetadata("Identity");
                 string name = Path.GetFileName(fullPath);
-                string directory = Path.Join(AppDir, config.AssemblyRoot, culture);
+                string directory = Path.Combine(AppDir, config.AssemblyRoot, culture);
                 Directory.CreateDirectory(directory);
-                FileCopyChecked(fullPath, Path.Join(directory, name), "SatelliteAssemblies");
+                FileCopyChecked(fullPath, Path.Combine(directory, name), "SatelliteAssemblies");
                 config.Assets.Add(new SatelliteAssemblyEntry(name, culture));
             }
         }
 
         if (FilesToIncludeInFileSystem != null)
         {
-            string supportFilesDir = Path.Join(AppDir, "supportFiles");
+            string supportFilesDir = Path.Combine(AppDir, "supportFiles");
             Directory.CreateDirectory(supportFilesDir);
 
             var i = 0;
@@ -216,7 +216,7 @@ public override bool Execute ()
 
                 var generatedFileName = $"{i++}_{Path.GetFileName(item.ItemSpec)}";
 
-                FileCopyChecked(item.ItemSpec, Path.Join(supportFilesDir, generatedFileName), "FilesToIncludeInFileSystem");
+                FileCopyChecked(item.ItemSpec, Path.Combine(supportFilesDir, generatedFileName), "FilesToIncludeInFileSystem");
 
                 var asset = new VfsEntry ($"supportFiles/{generatedFileName}") {
                     VirtualPath = targetPath
@@ -246,7 +246,7 @@ public override bool Execute ()
             config.Extra[name] = valueObject;
         }
 
-        string monoConfigPath = Path.Join(AppDir, "mono-config.js");
+        string monoConfigPath = Path.Combine(AppDir, "mono-config.js");
         using (var sw = File.CreateText(monoConfigPath))
         {
             var json = JsonSerializer.Serialize (config, new JsonSerializerOptions { WriteIndented = true });
@@ -284,9 +284,9 @@ private bool TryParseExtraConfigValue(ITaskItem extraItem, out object? valueObje
             return true;
 
         // Try parsing as a quoted string
-        if (rawValue!.Length > 1 && rawValue![0] == '"' && rawValue![^1] == '"')
+        if (rawValue!.Length > 1 && rawValue![0] == '"' && rawValue![rawValue!.Length - 1] == '"')
         {
-            valueObject = rawValue![1..^1];
+            valueObject = rawValue!.Substring(1, rawValue!.Length - 2);
             return true;
         }
 

src/tasks/WasmAppBuilder/WasmAppBuilder.csproj

@@ -1,10 +1,15 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>$(NetCoreAppToolCurrent)</TargetFramework>
+    <TargetFrameworks>$(NetCoreAppToolCurrent);net472</TargetFrameworks>
     <Nullable>enable</Nullable>
     <NoWarn>$(NoWarn),CA1050</NoWarn>
+
+    <!-- Ignore nullable warnings on net4* -->
+    <NoWarn Condition="$(TargetFramework.StartsWith('net4'))">$(NoWarn),CS8604,CS8602</NoWarn>
   </PropertyGroup>
   <ItemGroup>
+    <Compile Include="..\Common\NotNullAttribute.cs" Condition="$(TargetFramework.StartsWith('net4'))" />
+
     <PackageReference Include="Microsoft.Build" Version="$(RefOnlyMicrosoftBuildVersion)" />
     <PackageReference Include="Microsoft.Build.Framework" Version="$(RefOnlyMicrosoftBuildFrameworkVersion)" />
     <PackageReference Include="Microsoft.Build.Tasks.Core" Version="$(RefOnlyMicrosoftBuildTasksCoreVersion)" />
@@ -13,13 +18,24 @@
   </ItemGroup>
 
   <Target Name="PublishBuilder"
-          AfterTargets="Build"
-          DependsOnTargets="Publish" />
+          AfterTargets="Build">
+
+    <!-- needed for publishing with multi-targeting. We are publishing essentially to get the SR.MetadataLoadContext.dll :/ -->
+    <ItemGroup>
+      <_PublishFramework Include="$(TargetFrameworks)" />
+    </ItemGroup>
+    <MSBuild Projects="$(MSBuildProjectFile)" Targets="Publish" Properties="TargetFramework=%(_PublishFramework.Identity)" />
+  </Target>
 
   <Target Name="GetFilesToPackage" Returns="@(FilesToPackage)">
     <ItemGroup>
-      <FilesToPackage Include="$(OutputPath)$(MSBuildProjectName)*" TargetPath="tasks" />
-      <FilesToPackage Include="$(PublishDir)System.Reflection.MetadataLoadContext.dll" TargetPath="tasks" />
+      <_PublishFramework Remove="@(_PublishFramework)" />
+      <_PublishFramework Include="$(TargetFrameworks)" />
+
+      <FilesToPackage Include="$(OutputPath)%(_PublishFramework.Identity)\$(MSBuildProjectName)*"
+                      TargetPath="tasks\%(_PublishFramework.Identity)" />
+      <FilesToPackage Include="$(OutputPath)%(_PublishFramework.Identity)\publish\System.Reflection.MetadataLoadContext.dll"
+                      TargetPath="tasks\%(_PublishFramework.Identity)" />
     </ItemGroup>
   </Target>