WIP: arcade-powered-source-build

This enables 'source-build', which makes it easier to build the entire
shipping .NET SDK from source.

This is the first and second step of arcade-powered-source-build:
https://github.com/dotnet/source-build/blob/master/Documentation/planning/arcade-powered-source-build/README.md

See dotnet/sourcelink#692 for a similar PR, that this is based on.

.gitignore

@@ -142,7 +142,6 @@ node_modules/
 *.Tests/lib/
 *.userprefs
 *.vsp
-*.xml
 .idea
 _NCrunch_*/
 _ReSharper.*/

.vsts-ci.yml

@@ -29,6 +29,7 @@ stages:
       enablePublishTestResults: true
       enablePublishBuildAssets: true
       enableTelemetry: true
+      enableSourceBuild: true
       helixRepo: dotnet/command-line-api
       timeoutInMinutes: 180 # increase timeout since BAR publishing might wait a long time
       jobs:

eng/SouceBuild.props

@@ -0,0 +1,23 @@
+<Project>
+
+  <PropertyGroup>
+    <GitHubRepositoryName>command-line-api</GitHubRepositoryName>
+    <SourceBuildManagedOnly>true</SourceBuildManagedOnly>
+  </PropertyGroup>
+
+  <Target Name="ApplySourceBuildPatchFiles"
+          Condition="
+            '$(ArcadeBuildFromSource)' == 'true' and
+            '$(ArcadeInnerBuildFromSource)' == 'true'"
+          BeforeTargets="Execute">
+    <ItemGroup>
+      <SourceBuildPatchFile Include="$(RepositoryEngineeringDir)source-build-patches\*.patch" />
+    </ItemGroup>
+
+    <Exec
+      Command="git apply --ignore-whitespace --whitespace=nowarn &quot;%(SourceBuildPatchFile.FullPath)&quot;"
+      WorkingDirectory="$(RepoRoot)"
+      Condition="'@(SourceBuildPatchFile)' != ''" />
+  </Target>
+
+</Project>

eng/SourceBuild.props

@@ -0,0 +1,8 @@
+<Project>
+
+  <PropertyGroup>
+    <GitHubRepositoryName>command-line-api</GitHubRepositoryName>
+    <SourceBuildManagedOnly>true</SourceBuildManagedOnly>
+  </PropertyGroup>
+
+</Project>

eng/SourceBuildPrebuiltBaseline.xml

@@ -0,0 +1,5 @@
+<UsageData>
+  <IgnorePatterns>
+    <UsagePattern IdentityGlob="*/*" />
+  </IgnorePatterns>
+</UsageData>

eng/Version.Details.xml

@@ -6,6 +6,8 @@
     <Dependency Name="Microsoft.DotNet.Arcade.Sdk" Version="6.0.0-beta.20573.2">
       <Uri>https://github.com/dotnet/arcade</Uri>
       <Sha>35bddd4fbfab8da3518fb920250d7c9e0c3138ff</Sha>
+      <!--<SourceBuild RepoName="arcade" ManagedOnly="true"/> -->
+
     </Dependency>
   </ToolsetDependencies>
 </Dependencies>

eng/source-build-patches/0002-Use-package-version-properties-for-reference-version.patch

@@ -0,0 +1,47 @@
+From 74c9b072853ff4d68f2630462a6f1ac5d576979d Mon Sep 17 00:00:00 2001
+From: Chris Rummel <crummel@microsoft.com>
+Date: Mon, 21 Sep 2020 09:59:02 -0500
+Subject: [PATCH 2/2] Use package version properties for reference versions.
+
+---
+ eng/Versions.props                                         | 7 +++++--
+ src/System.CommandLine/System.CommandLine.csproj           | 4 ++--
+ 2 files changed, 7 insertions(+), 4 deletions(-)
+
+diff --git a/eng/Versions.props b/eng/Versions.props
+index 3048701..16a0eb7 100644
+--- a/eng/Versions.props
++++ b/eng/Versions.props
+@@ -29,9 +29,12 @@
+     <UsingToolSymbolUploader>true</UsingToolSymbolUploader>
+     <PublishWindowsPdb>true</PublishWindowsPdb>
+   </PropertyGroup>
+-  <!--   <PropertyGroup>
++  <PropertyGroup>
+     <FluentAssertionsVersion>4.18.0</FluentAssertionsVersion>
+     <NewtonsoftJsonVersion>9.0.1</NewtonsoftJsonVersion>
+     <SystemNetHttpVersion>4.3.1</SystemNetHttpVersion>
+-  </PropertyGroup>  -->
++    <MicrosoftExtensionsHostingPackageVersion Condition="'$(MicrosoftExtensionsHostingPackageVersion)' == ''">2.2.0</MicrosoftExtensionsHostingPackageVersion>
++    <MicrosoftCSharpPackageVersion Condition="'$(MicrosoftCSharpPackageVersion)' == ''">4.4.1</MicrosoftCSharpPackageVersion>
++    <SystemMemoryPackageVersion Condition="'$(SystemMemoryPackageVersion)' == ''">4.5.3</SystemMemoryPackageVersion>
++  </PropertyGroup>
+ </Project>
+diff --git a/src/System.CommandLine/System.CommandLine.csproj b/src/System.CommandLine/System.CommandLine.csproj
+index 1ae8dd3..aaa2c4a 100644
+--- a/src/System.CommandLine/System.CommandLine.csproj
++++ b/src/System.CommandLine/System.CommandLine.csproj
+@@ -19,8 +19,8 @@
+   </PropertyGroup>
+
+   <ItemGroup>
+-    <PackageReference Include="Microsoft.CSharp" Version="4.4.1" />
+-    <PackageReference Include="system.memory" Version="4.5.3" />
++    <PackageReference Include="Microsoft.CSharp" Version="$(MicrosoftCSharpPackageVersion)" />
++    <PackageReference Include="system.memory" Version="$(SystemMemoryPackageVersion)" />
+   </ItemGroup>
+
+ </Project>
+--
+2.18.0
+

eng/source-build-patches/0003-Update-to-netcoreapp3.1-to-avoid-prebuilts.patch

@@ -0,0 +1,95 @@
+From b9a21ec1c0a77ef4e1e44840a0526545fea456de Mon Sep 17 00:00:00 2001
+From: Davis Goodin <dagood@microsoft.com>
+Date: Thu, 29 Oct 2020 01:48:54 -0500
+Subject: [PATCH] Update to netcoreapp3.1 to avoid prebuilts
+
+netcoreapp3.1 avoids prebuilts (Microsoft.CSharp) but works with the
+rest of source-build: runtime and roslyn.
+
+Includes a code fix for ref nullability with the new framework.
+---
+ .../System.CommandLine.DragonFruit.csproj                  | 2 +-
+ .../System.CommandLine.Hosting.csproj                      | 2 +-
+ .../System.CommandLine.Rendering.csproj                    | 2 +-
+ src/System.CommandLine/Binding/BindingContext.cs           | 2 +-
+ src/System.CommandLine/System.CommandLine.csproj           | 7 +------
+ 5 files changed, 5 insertions(+), 10 deletions(-)
+
+diff --git a/src/System.CommandLine.DragonFruit/System.CommandLine.DragonFruit.csproj b/src/System.CommandLine.DragonFruit/System.CommandLine.DragonFruit.csproj
+index b3a542fd..06167997 100644
+--- a/src/System.CommandLine.DragonFruit/System.CommandLine.DragonFruit.csproj
++++ b/src/System.CommandLine.DragonFruit/System.CommandLine.DragonFruit.csproj
+@@ -1,7 +1,7 @@
+ <Project Sdk="Microsoft.NET.Sdk">
+   <PropertyGroup>
+     <IsPackable>true</IsPackable>
+-    <TargetFramework>netstandard2.0</TargetFramework>
++    <TargetFramework>netcoreapp3.1</TargetFramework>
+     <Description>This package includes the experimental DragonFruit app model for System.CommandLine, which allows you to create a command line application using only a Main method while getting support for complex type binding, error reporting, help, shell completions, and more.
+     </Description>
+   </PropertyGroup>
+diff --git a/src/System.CommandLine.Hosting/System.CommandLine.Hosting.csproj b/src/System.CommandLine.Hosting/System.CommandLine.Hosting.csproj
+index 1d00cff2..7342c1c5 100644
+--- a/src/System.CommandLine.Hosting/System.CommandLine.Hosting.csproj
++++ b/src/System.CommandLine.Hosting/System.CommandLine.Hosting.csproj
+@@ -2,7 +2,7 @@
+
+   <PropertyGroup>
+     <IsPackable>true</IsPackable>
+-    <TargetFramework>netstandard2.0</TargetFramework>
++    <TargetFramework>netcoreapp3.1</TargetFramework>
+     <LangVersion>latest</LangVersion>
+     <Description>This package provides support for using System.CommandLine with Microsoft.Extensions.Hosting.</Description>
+   </PropertyGroup>
+diff --git a/src/System.CommandLine.Rendering/System.CommandLine.Rendering.csproj b/src/System.CommandLine.Rendering/System.CommandLine.Rendering.csproj
+index d552286e..84026ebe 100644
+--- a/src/System.CommandLine.Rendering/System.CommandLine.Rendering.csproj
++++ b/src/System.CommandLine.Rendering/System.CommandLine.Rendering.csproj
+@@ -2,7 +2,7 @@
+
+   <PropertyGroup>
+     <IsPackable>true</IsPackable>
+-    <TargetFramework>netstandard2.0</TargetFramework>
++    <TargetFramework>netcoreapp3.1</TargetFramework>
+     <LangVersion>7.3</LangVersion>
+     <Description>This package provides support for structured command line output rendering. Write code once that renders correctly in multiple output modes, including System.Console, virtual terminal (using ANSI escape sequences), and plain text.
+     </Description>
+diff --git a/src/System.CommandLine/Binding/BindingContext.cs b/src/System.CommandLine/Binding/BindingContext.cs
+index b942ba6a..bbb83891 100644
+--- a/src/System.CommandLine/Binding/BindingContext.cs
++++ b/src/System.CommandLine/Binding/BindingContext.cs
+@@ -55,7 +55,7 @@ namespace System.CommandLine.Binding
+
+         public ModelBinder GetModelBinder(IValueDescriptor valueDescriptor)
+         {
+-            if (_modelBindersByValueDescriptor.TryGetValue(valueDescriptor.ValueType, out ModelBinder binder))
++            if (_modelBindersByValueDescriptor.TryGetValue(valueDescriptor.ValueType, out ModelBinder? binder))
+             {
+                 return binder;
+             }
+diff --git a/src/System.CommandLine/System.CommandLine.csproj b/src/System.CommandLine/System.CommandLine.csproj
+index aaa2c4a3..5e875a73 100644
+--- a/src/System.CommandLine/System.CommandLine.csproj
++++ b/src/System.CommandLine/System.CommandLine.csproj
+@@ -3,7 +3,7 @@
+   <PropertyGroup>
+     <IsPackable>true</IsPackable>
+     <PackageId>System.CommandLine</PackageId>
+-    <TargetFramework>netstandard2.0</TargetFramework>
++    <TargetFramework>netcoreapp3.1</TargetFramework>
+     <LangVersion>8</LangVersion>
+     <Description>This package includes a powerful command line parser and other tools for building command line applications, including:
+
+@@ -18,9 +18,4 @@
+     <DebugType>portable</DebugType>
+   </PropertyGroup>
+
+-  <ItemGroup>
+-    <PackageReference Include="Microsoft.CSharp" Version="$(MicrosoftCSharpPackageVersion)" />
+-    <PackageReference Include="system.memory" Version="$(SystemMemoryPackageVersion)" />
+-  </ItemGroup>
+-
+ </Project>
+-- 
+2.25.2
+

eng/source-build-patches/0004-Exclude-System.CommandLine.Hosting.patch

@@ -0,0 +1,25 @@
+From f4053c72fd35e1ec0b238cb5f27f818b837a3632 Mon Sep 17 00:00:00 2001
+From: Davis Goodin <dagood@microsoft.com>
+Date: Thu, 5 Nov 2020 10:48:59 -0600
+Subject: [PATCH] Exclude System.CommandLine.Hosting
+
+This project is not used by downstream repos and restores prebuilts.
+---
+ src/System.CommandLine.Hosting/System.CommandLine.Hosting.csproj | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/src/System.CommandLine.Hosting/System.CommandLine.Hosting.csproj b/src/System.CommandLine.Hosting/System.CommandLine.Hosting.csproj
+index 7342c1c..e4a97a0 100644
+--- a/src/System.CommandLine.Hosting/System.CommandLine.Hosting.csproj
++++ b/src/System.CommandLine.Hosting/System.CommandLine.Hosting.csproj
+@@ -5,6 +5,7 @@
+     <TargetFramework>netcoreapp3.1</TargetFramework>
+     <LangVersion>latest</LangVersion>
+     <Description>This package provides support for using System.CommandLine with Microsoft.Extensions.Hosting.</Description>
++    <ExcludeFromSourceBuild>true</ExcludeFromSourceBuild>
+   </PropertyGroup>
+
+   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
+-- 
+2.25.2
+