dotnet · benvillalobos · Mar 7, 2022 · Feb 10, 2021 · Feb 17, 2021 · Feb 11, 2021
@@ -10,7 +10,7 @@
   <ItemGroup>
     <PackageReference Update="Microsoft.Build.NuGetSdkResolver" Version="$(NuGetBuildTasksVersion)" />
     <PackageReference Update="Microsoft.CodeAnalysis.Build.Tasks" Version="$(MicrosoftNetCompilersToolsetVersion)" />
-    <PackageReference Update="Microsoft.CodeAnalysis.Collections" Version="4.0.0-4.21379.20" />
+    <PackageReference Update="Microsoft.CodeAnalysis.Collections" Version="4.2.0-1.22102.8" />
     <PackageReference Update="Microsoft.DotNet.XUnitExtensions" Version="$(MicrosoftDotNetXUnitExtensionsVersion)" />
     <PackageReference Update="Microsoft.IO.Redist" Version="6.0.0" />
     <PackageReference Update="Microsoft.Net.Compilers.Toolset" Version="$(MicrosoftNetCompilersToolsetVersion)" />

diff --git a/src/Build.UnitTests/Microsoft.Build.Engine.UnitTests.csproj b/src/Build.UnitTests/Microsoft.Build.Engine.UnitTests.csproj
@@ -36,9 +36,9 @@
     <ProjectReference Include="..\Samples\TaskWithDependency\TaskWithDependency.csproj" Private="false" ReferenceOutputAssembly="false" OutputItemType="TaskWithDependencyResolvedProjectReferencePath">
       <SetTargetFramework Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'">TargetFramework=$(FullFrameworkTFM)</SetTargetFramework>
       <SetTargetFramework Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework' and '$(MonoBuild)' == 'true'">TargetFramework=$(FullFrameworkTFM)</SetTargetFramework>
-      <SetTargetFramework Condition="'$(TargetFrameworkIdentifier)' != '.NETFramework'">TargetFramework=netstandard2.0</SetTargetFramework>
+      <SetTargetFramework Condition="'$(TargetFrameworkIdentifier)' != '.NETFramework'">TargetFramework=net6.0</SetTargetFramework>
     </ProjectReference>
-    <ProjectReference Include="..\Samples\PortableTask\PortableTask.csproj" Private="false" ReferenceOutputAssembly="false" OutputItemType="PortableTaskResolvedProjectReferencePath" SetTargetFramework="TargetFramework=netstandard2.0" />
+    <ProjectReference Include="..\Samples\PortableTask\PortableTask.csproj" Private="false" ReferenceOutputAssembly="false" OutputItemType="PortableTaskResolvedProjectReferencePath" />
 
     <ProjectReference Include="..\Samples\ProjectCachePlugin\ProjectCachePlugin.csproj" Private="false" ReferenceOutputAssembly="false">
       <SetTargetFramework Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'">TargetFramework=$(FullFrameworkTFM)</SetTargetFramework>

diff --git a/src/Directory.BeforeCommon.targets b/src/Directory.BeforeCommon.targets
@@ -82,7 +82,7 @@
 
   <PropertyGroup Condition="'$(MonoBuild)' != 'true' and ($([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETCoreApp' or $([MSBuild]::GetTargetFrameworkIdentifier('$(TargetFramework)')) == '.NETStandard')">
     <NetCoreBuild>true</NetCoreBuild>
-    <DefineConstants>$(DefineConstants);RUNTIME_TYPE_NETCORE</DefineConstants>
+    <DefineConstants>$(DefineConstants);RUNTIME_TYPE_NETCORE;FEATURE_FASTSPAN</DefineConstants>
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(NetCoreBuild)'=='true'">

diff --git a/src/Directory.Build.props b/src/Directory.Build.props
@@ -15,6 +15,9 @@
     <!-- Ensure that compiler errors emit full paths so that files
          can be correctly annotated in GitHub. -->
     <GenerateFullPaths>true</GenerateFullPaths>
+
+    <!-- https://github.com/NuGet/Home/issues/8684 -->
+    <NoWarn>$(NoWarn);NU5131</NoWarn>
 
     <!-- Do not mangle paths for test assemblies, because Shoudly assertions want actual on-disk paths. -->
     <DeterministicSourcePaths Condition="'$(IsTestProject)' == 'true'">false</DeterministicSourcePaths>
@@ -27,8 +30,9 @@
     <Platforms>AnyCPU;x64</Platforms>
 
     <!-- Defaults for target frameworks and architecture -->
-    <LibraryTargetFrameworks>$(FullFrameworkTFM);netstandard2.0</LibraryTargetFrameworks>
-    <LibraryTargetFrameworks Condition="'$(MonoBuild)'=='true'">$(FullFrameworkTFM)</LibraryTargetFrameworks>
+    <LibraryTargetFrameworks>$(FullFrameworkTFM);net6.0;netstandard2.0</LibraryTargetFrameworks>
+    <LibraryTargetFrameworks Condition="'$(DotNetBuildFromSource)' == 'true'">net6.0;netstandard2.0</LibraryTargetFrameworks>
+    <LibraryTargetFrameworks Condition="'$(MonoBuild)'=='true'">$(FullFrameworkTFM);netstandard2.0</LibraryTargetFrameworks>
     <PlatformTarget>AnyCPU</PlatformTarget>
 
     <!-- Target frameworks for Exe and unit test projects (ie projects with runtime output) -->
@@ -71,4 +75,34 @@
     <!-- When targeting .NET Core, Exe and unit tests projects always use AnyCPU architecture -->
     <RuntimeOutputPlatformTarget>AnyCPU</RuntimeOutputPlatformTarget>
   </PropertyGroup>
+
+  <PropertyGroup>
+    <TargetsForTfmSpecificBuildOutput>$(TargetsForTfmSpecificContentInPackage);ShipRefAssembliesToNuGetPackage</TargetsForTfmSpecificBuildOutput>
+  </PropertyGroup>
+
+  <!-- Produce ONLY reference assemblies and SKIP roslyn analyzers for netstandard2.0 builds. -->
+  <PropertyGroup Condition="'$(TargetFramework)' == 'netstandard2.0' and '$(MSBuildProjectFile)' != 'PortableTask.csproj'">
+    <!-- ProduceOnlyReferenceAssembly and ProduceReferenceAssembly are mutually exclusive compiler flags. -->
+    <ProduceOnlyReferenceAssembly>true</ProduceOnlyReferenceAssembly>
+    <ProduceReferenceAssembly>false</ProduceReferenceAssembly>
+    <RunAnalyzers>false</RunAnalyzers>
+    <TargetsForTfmSpecificBuildOutput>$(TargetsForTfmSpecificContentInPackage);ShipRefAssembliesToNuGetPackage</TargetsForTfmSpecificBuildOutput>
+    <IncludeBuildOutput>false</IncludeBuildOutput>
+    <!-- pdb publishing fails builds for reference-only assemblies. -->
+    <!-- https://github.com/dotnet/msbuild/pull/6148. -->
+    <PublishWindowsPdb>false</PublishWindowsPdb>
+  </PropertyGroup>
+
+  <!-- Ensure ref assemblies are placed under `ref/$(TargetFramework)` in the NuGet package -->
+  <Target Name="ShipRefAssembliesToNuGetPackage" BeforeTargets="Pack" Condition="$(IsInnerBuild) == true">
+    <ItemGroup>
+      <TfmSpecificPackageFile Include="$(TargetRefPath);@(FinalDocFile)">
+          <PackagePath>ref\$(TargetFramework)</PackagePath>
+      </TfmSpecificPackageFile>
+      <!-- ns2.0 builds use `BuiltProjectOutputGroupOutput` for output ref assemblies -->
+      <TfmSpecificPackageFile Include="@(BuiltProjectOutputGroupOutput)" Condition="'$(TargetFramework)' == 'netstandard2.0'">
+          <PackagePath>ref\$(TargetFramework)</PackagePath>
+      </TfmSpecificPackageFile>
+    </ItemGroup>
+  </Target>
 </Project>
diff --git a/src/Framework/NativeMethods.cs b/src/Framework/NativeMethods.cs
@@ -9,6 +9,7 @@
 using System.IO;
 using System.Reflection;
 using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
 using System.Text;
 using System.Threading;
 
@@ -21,9 +22,10 @@
 #nullable disable
 
 namespace Microsoft.Build.Framework;
+
 internal static class NativeMethods
 {
-    #region Constants
+#region Constants
 
     internal const uint ERROR_INSUFFICIENT_BUFFER = 0x8007007A;
     internal const uint STARTUP_LOADER_SAFEMODE = 0x10;
@@ -71,9 +73,9 @@ internal static class NativeMethods
     internal const uint WAIT_OBJECT_0 = 0x00000000;
     internal const uint WAIT_TIMEOUT = 0x00000102;
 
-    #endregion
+#endregion
 
-    #region Enums
+#region Enums
 
     private enum PROCESSINFOCLASS : int
     {
@@ -198,9 +200,9 @@ internal enum ProcessorArchitectures
         Unknown
     }
 
-    #endregion
+#endregion
 
-    #region Structs
+#region Structs
 
     /// <summary>
     /// Structure that contain information about the system on which we are running
@@ -568,9 +570,9 @@ private unsafe static int GetLogicalCoreCountOnWindows()
         return -1;
     }
 
-    #endregion
+#endregion
 
-    #region Member data
+#region Member data
 
     internal static bool HasMaxPath => MaxPath == MAX_PATH;
 
@@ -709,10 +711,10 @@ internal static bool IsMono
 #if !CLR2COMPATIBILITY
     private static bool? _isWindows;
 #endif
-
     /// <summary>
     /// Gets a flag indicating if we are running under some version of Windows
     /// </summary>
+    [SupportedOSPlatformGuard("windows")]
     internal static bool IsWindows
     {
 #if CLR2COMPATIBILITY
@@ -867,9 +869,9 @@ private static SystemInformationData SystemInformation
     /// </summary>
     internal static ProcessorArchitectures ProcessorArchitectureNative => SystemInformation.ProcessorArchitectureTypeNative;
 
-    #endregion
+#endregion
 
-    #region Wrapper methods
+#region Wrapper methods
 
     /// <summary>
     /// Really truly non pumping wait.
@@ -1451,9 +1453,9 @@ internal static void VerifyThrowWin32Result(int result)
         }
     }
 
-    #endregion
+#endregion
 
-    #region PInvoke
+#region PInvoke
 
     /// <summary>
     /// Gets the current OEM code page which is used by console apps
@@ -1609,9 +1611,9 @@ out FILETIME lpLastWriteTime
     [DllImport("kernel32.dll", SetLastError = true)]
     internal static extern bool SetThreadErrorMode(int newMode, out int oldMode);
 
-    #endregion
+#endregion
 
-    #region Extensions
+#region Extensions
 
     /// <summary>
     /// Waits while pumping APC messages.  This is important if the waiting thread is an STA thread which is potentially
@@ -1654,9 +1656,9 @@ internal static bool MsgWaitOne(this WaitHandle handle, int timeout)
         return returnValue == 0;
     }
 
-    #endregion
+#endregion
 
-    #region helper methods
+#region helper methods
 
     internal static bool DirectoryExists(string fullPath)
     {
@@ -1699,6 +1701,6 @@ internal static bool FileOrDirectoryExistsWindows(string path)
         return GetFileAttributesEx(path, 0, ref data);
     }
 
-    #endregion
+#endregion
 
 }
diff --git a/src/Framework/README.md b/src/Framework/README.md
@@ -4,3 +4,8 @@ This package contains `Microsoft.Build.Framework.dll`, which defines [fundamenta
 
 The items in this namespace are primarily base-level classes and interfaces shared across MSBuild's object model.  MSBuild task or extension developers can reference this package to implement interfaces such as
 [`ITask`](https://docs.microsoft.com/dotnet/api/microsoft.build.framework.itask), and [`ILogger`](https://docs.microsoft.com/dotnet/api/microsoft.build.framework.ilogger).
+
+### netstandard2.0 target
+The `netstandard2.0` target of this build is configured only to output reference assemblies; at runtime MSBuild will be `net6.0` or `net472`. Please use the `net6.0`-targeted assemblies for .NET Core 6+ scenarios.
+
+For context, see https://github.com/dotnet/msbuild/pull/6148
diff --git a/src/Framework/Sdk/SdkResultItem.cs b/src/Framework/Sdk/SdkResultItem.cs
@@ -36,7 +36,7 @@ public SdkResultItem(string itemSpec, Dictionary<string, string>? metadata)
             Metadata = metadata;
         }
 
-        public override bool Equals(object obj)
+        public override bool Equals(object? obj)
         {
             if (obj is SdkResultItem item &&
                    ItemSpec == item.ItemSpec &&

diff --git a/src/Framework/SupportedOSPlatform.cs b/src/Framework/SupportedOSPlatform.cs
@@ -0,0 +1,27 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+#if !NET6_0_OR_GREATER
+namespace System.Runtime.Versioning
+{
+    /// <summary>
+    /// SupportedOSPlatform is a net5.0+ Attribute.
+    /// Create the same type only in full-framework and netstandard2.0 builds
+    /// to prevent many #if RUNTIME_TYPE_NETCORE checks.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Method | AttributeTargets.Property)]
+    internal class SupportedOSPlatformGuard : Attribute
+    {
+        internal SupportedOSPlatformGuard(string platformName)
+        {
+        }
+    }
+    [AttributeUsage(AttributeTargets.Method | AttributeTargets.Property | AttributeTargets.Class)]
+    internal class SupportedOSPlatform : Attribute
+    {
+        internal SupportedOSPlatform(string platformName)
+        {
+        }
+    }
+}
+#endif
diff --git a/src/MSBuild/MSBuild.csproj b/src/MSBuild/MSBuild.csproj
@@ -211,6 +211,13 @@
     <PackageReference Include="Microsoft.IO.Redist" Condition="'$(FeatureMSIORedist)' == 'true'" />
     <PackageReference Include="System.Configuration.ConfigurationManager" />
   </ItemGroup>
+    <!-- Manually download this library for RoslynCodeTaskFactory.
+           See target AddRefAssemblies below. -->
+    <ItemGroup>
+      <PackageDownload Include="netstandard.library">
+        <Version>[2.0.3]</Version>
+      </PackageDownload>
+    </ItemGroup>
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'">
     <!-- File for Assemblies we depend on -->
     <Reference Include="System" />

diff --git a/src/MSBuildTaskHost/MSBuildTaskHost.csproj b/src/MSBuildTaskHost/MSBuildTaskHost.csproj
@@ -142,6 +142,9 @@
     <Compile Include="..\Framework\StringBuilderCache.cs">
       <Link>StringBuilderCache.cs</Link>
     </Compile>
+    <Compile Include="..\Framework\SupportedOSPlatform.cs">
+      <Link>SupportedOSPlatform.cs</Link>
+    </Compile>
     <Compile Include="..\Shared\TaskEngineAssemblyResolver.cs">
       <Link>TaskEngineAssemblyResolver.cs</Link>
     </Compile>

diff --git a/src/Samples/PortableTask/PortableTask.csproj b/src/Samples/PortableTask/PortableTask.csproj
@@ -3,7 +3,7 @@
     <UseProductOutputPath>true</UseProductOutputPath>
     <CopyNuGetImplementations>false</CopyNuGetImplementations>
     <GenerateAssemblyInfo>false</GenerateAssemblyInfo>
-    <TargetFrameworks>netstandard2.0</TargetFrameworks>
+    <TargetFramework>netstandard2.0</TargetFramework>
   </PropertyGroup>
   <ItemGroup>
     <Content Include="portableTaskTest.proj">

diff --git a/src/StringTools/InternableString.cs b/src/StringTools/InternableString.cs
@@ -96,7 +96,7 @@ public bool MoveNext()
         /// </summary>
         private readonly ReadOnlySpan<char> _inlineSpan;
 
-#if NETSTANDARD
+#if FEATURE_FASTSPAN
         /// <summary>
         /// .NET Core does not keep a reference to the containing object in <see cref="ReadOnlySpan{T}"/>. In particular,
         /// it cannot recover the string if the span represents one. We have to hold the reference separately to be able to
@@ -122,7 +122,7 @@ internal InternableString(ReadOnlySpan<char> span)
             _inlineSpan = span;
             _spans = null;
             Length = span.Length;
-#if NETSTANDARD
+#if FEATURE_FASTSPAN
             _inlineSpanString = null;
 #endif
         }
@@ -141,7 +141,7 @@ internal InternableString(string str)
             _inlineSpan = str.AsSpan();
             _spans = null;
             Length = str.Length;
-#if NETSTANDARD
+#if FEATURE_FASTSPAN
             _inlineSpanString = str;
 #endif
         }
@@ -154,7 +154,7 @@ internal InternableString(SpanBasedStringBuilder stringBuilder)
             _inlineSpan = default(ReadOnlySpan<char>);
             _spans = stringBuilder.Spans;
             Length = stringBuilder.Length;
-#if NETSTANDARD
+#if FEATURE_FASTSPAN
             _inlineSpanString = null;
 #endif
         }
@@ -220,7 +220,7 @@ public unsafe string ExpensiveConvertToString()
             // Special case: if we hold just one string, we can directly return it.
             if (_inlineSpan.Length == Length)
             {
-#if NETSTANDARD
+#if FEATURE_FASTSPAN
                 if (_inlineSpanString != null)
                 {
                     return _inlineSpanString;

diff --git a/src/StringTools/WeakStringCache.Concurrent.cs b/src/StringTools/WeakStringCache.Concurrent.cs
@@ -32,7 +32,7 @@ public string GetOrCreateEntry(ref InternableString internable, out bool cacheHi
         {
             int hashCode = internable.GetHashCode();
 
-            StringWeakHandle handle;
+            StringWeakHandle? handle;
             string? result;
 
             // Get the existing handle from the cache and lock it while we're dereferencing it to prevent a race with the Scavenge
@@ -98,7 +98,7 @@ public void Scavenge()
             foreach (KeyValuePair<int, StringWeakHandle> entry in _stringsByHashCode)
             {
                 // We can safely dereference entry.Value as the caller guarantees that Scavenge runs only on one thread.
-                if (!entry.Value.IsUsed && _stringsByHashCode.TryRemove(entry.Key, out StringWeakHandle removedHandle))
+                if (!entry.Value.IsUsed && _stringsByHashCode.TryRemove(entry.Key, out StringWeakHandle? removedHandle))
                 {
                     lock (removedHandle)
                     {

diff --git a/src/Tasks.UnitTests/AssemblyDependency/Miscellaneous.cs b/src/Tasks.UnitTests/AssemblyDependency/Miscellaneous.cs
@@ -14,7 +14,6 @@
 using SystemProcessorArchitecture = System.Reflection.ProcessorArchitecture;
 using Xunit.Abstractions;
 using Shouldly;
-using System.Text;
 
 #nullable disable
 

diff --git a/src/Tasks.UnitTests/Microsoft.Build.Tasks.UnitTests.csproj b/src/Tasks.UnitTests/Microsoft.Build.Tasks.UnitTests.csproj
@@ -25,7 +25,7 @@
     <ProjectReference Include="..\Tasks\Microsoft.Build.Tasks.csproj" />
     <ProjectReference Include="..\Utilities\Microsoft.Build.Utilities.csproj" />
     <ProjectReference Include="..\Xunit.NetCore.Extensions\Xunit.NetCore.Extensions.csproj" />
-    <ProjectReference Include="..\Samples\PortableTask\PortableTask.csproj" ReferenceOutputAssembly="false" Private="false" SetTargetFramework="TargetFramework=netstandard2.0" />
+    <ProjectReference Include="..\Samples\PortableTask\PortableTask.csproj" ReferenceOutputAssembly="false" Private="false" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(TargetFrameworkIdentifier)' == '.NETFramework'">