Generate equivalent of resx .Designer.cs in build

build/GenerateResxSource.targets

@@ -0,0 +1,45 @@
+<Project>
+
+  <UsingTask TaskName="GenerateResxSource" AssemblyFile="$(CLIBuildDll)" />
+
+ <Target Name="GenerateResxSource"
+         BeforeTargets="CoreCompile"
+         DependsOnTargets="PrepareResourceNames;
+                           GetEmbeddedResourcesWithSourceGeneration;
+                           BatchGenerateResxSource">
+    <ItemGroup>
+      <GeneratedResxSource Include="@(EmbeddedResourceSG->'%(SourceOutputPath)')" />
+      <FileWrites Include="@(GeneratedResxSource)" />
+      <Compile Include="@(GeneratedResxSource)" />
+    </ItemGroup>
+  </Target>
+
+  <Target Name="CustomizeResourceNames"
+          BeforeTargets="PrepareResourceNames"
+          >
+    <ItemGroup>
+      <EmbeddedResource>
+        <ManifestResourceName Condition="'%(EmbeddedResource.Namespace)' != ''">%(EmbeddedResource.Namespace).%(EmbeddedResource.Filename)</ManifestResourceName>
+      </EmbeddedResource>
+    </ItemGroup>
+  </Target>
+
+  <Target Name="BatchGenerateResxSource"
+          Inputs="@(EmbeddedResourceSG)"
+          Outputs="%(EmbeddedResourceSG.SourceOutputPath)"
+          >
+    <GenerateResxSource ResxFile="%(EmbeddedResourceSG.FullPath)"
+                        ResourceName="%(EmbeddedResourceSG.ManifestResourceName)" 
+                        SourceOutputPath="%(EmbeddedResourceSG.SourceOutputPath)" />
+  </Target>
+
+  <Target Name="GetEmbeddedResourcesWithSourceGeneration">
+    <ItemGroup>
+      <EmbeddedResourceSG Include="@(EmbeddedResource)" Condition="'%(EmbeddedResource.GenerateSource)' == 'true'" />
+      <EmbeddedResourceSG>
+        <SourceOutputPath>$(IntermediateOutputPath)%(EmbeddedResourceSG.ManifestResourceName).cs</SourceOutputPath>
+      </EmbeddedResourceSG>
+    </ItemGroup>
+  </Target>
+
+</Project>

build_projects/dotnet-cli-build/GenerateResxSource.cs

@@ -0,0 +1,58 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using Microsoft.Build.Framework;
+using Microsoft.Build.Utilities;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Xml.Linq;
+
+namespace Microsoft.DotNet.Cli.Build
+{
+    public class GenerateResxSource : Task
+    {
+
+        [Required]
+        public string ResxFile { get; set; }
+
+        [Required]
+        public string ResourceName { get; set; }
+
+        [Required]
+        public string SourceOutputPath { get; set; }
+
+        public override bool Execute()
+        {
+            var source = new StringBuilder();
+            void _(string line) { source.AppendLine(line); }
+
+            string @namespace = Path.GetFileNameWithoutExtension(ResourceName);
+            string @class = Path.GetExtension(ResourceName).TrimStart('.');
+
+            _($"using System;");
+            _($"using System.Globalization;");
+            _($"using System.Reflection;");
+            _($"using System.Resources;");
+            _($"");
+            _($"namespace {@namespace}");
+            _($"{{");
+            _($"    internal static class {@class}");
+            _($"    {{");
+            _($"        internal static CultureInfo Culture {{ get; set; }}");
+            _($"        internal static ResourceManager ResourceManager {{ get; }} = new ResourceManager(\"{ResourceName}\", typeof({@class}).GetTypeInfo().Assembly);");
+
+            foreach (var key in XDocument.Load(ResxFile)
+                                         .Descendants("data")
+                                         .Select(n => n.Attribute("name").Value))
+            {
+            _($"        internal static string {key} => ResourceManager.GetString(\"{key}\", Culture);");
+            }
+            _($"    }}");
+            _($"}}");
+
+            File.WriteAllText(SourceOutputPath, source.ToString());
+            return true;
+        }
+    }
+}

dir.props

@@ -41,4 +41,5 @@
 
   <Import Project="build/AzureInfo.props" />
   <Import Project="build/InstallerInfo.props" />
+  <Import Project="build/GenerateResxSource.targets" />
 </Project>