Fix dotnet/Mono build and testing under Linux

src/csharp/Grpc.Tools.Tests/Grpc.Tools.Tests.csproj

@@ -3,7 +3,7 @@
   <Import Project="..\Grpc.Core\Version.csproj.include" />
 
   <PropertyGroup>
-    <TargetFrameworks>net45;netcoreapp1.0</TargetFrameworks>
+    <TargetFrameworks>net45;netcoreapp1.0;netcoreapp2.1</TargetFrameworks>
     <OutputType>Exe</OutputType>
   </PropertyGroup>
 
@@ -14,8 +14,8 @@
        and may not compile Grpc.Core/Version.cs, as that file references constants
        in Grpc.Core.dll.
        TODO(kkm): Refactor imports. -->
-  <PropertyGroup Condition="'$(OS)' != 'Windows_NT'">
-    <!-- Workaround for https://github.com/dotnet/sdk/issues/335 -->
+  <PropertyGroup Condition=" '$(OS)' != 'Windows_NT' and '$(MSBuildRuntimeType)' == 'Core' ">
+    <!-- Use Mono reference assemblies in SDK build: https://github.com/dotnet/sdk/issues/335 -->
     <FrameworkPathOverride Condition="Exists('/usr/lib/mono/4.5-api')">/usr/lib/mono/4.5-api</FrameworkPathOverride>
     <FrameworkPathOverride Condition="Exists('/usr/local/lib/mono/4.5-api')">/usr/local/lib/mono/4.5-api</FrameworkPathOverride>
     <FrameworkPathOverride Condition="Exists('/Library/Frameworks/Mono.framework/Versions/Current/lib/mono/4.5-api')">/Library/Frameworks/Mono.framework/Versions/Current/lib/mono/4.5-api</FrameworkPathOverride>
@@ -27,16 +27,47 @@
 
   <ItemGroup>
     <PackageReference Include="Moq" Version="4.8.3" />
-    <PackageReference Include="NUnit" Version="3.10.1" />
-    <PackageReference Include="NUnitLite" Version="3.10.1" />
-  </ItemGroup>
-
-  <ItemGroup Condition=" '$(TargetFramework)' == 'netcoreapp1.0' ">
-    <PackageReference Include="Microsoft.Build.Framework; Microsoft.Build.Utilities.Core" Version="15.6.85" />
+    <PackageReference Include="NUnit; NUnitLite" Version="3.10.1" />
   </ItemGroup>
 
   <ItemGroup Condition=" '$(TargetFramework)' == 'net45' ">
     <Reference Include="Microsoft.Build.Framework; Microsoft.Build.Utilities.v4.0" />
   </ItemGroup>
 
+  <ItemGroup Condition=" '$(TargetFramework)' != 'net45' ">
+    <PackageReference Include="Microsoft.Build.Framework; Microsoft.Build.Utilities.Core" Version="15.6.*" />
+  </ItemGroup>
+
+  <!-- Groups below is a hack to allow the test to run under Mono Framework build.
+       ========================================================================== -->
+
+  <!-- Mono unfortunately comes with broken Microsoft.Build.* assemblies installed in
+       the GAC, but fortunately searches for runtime assemblies in a different order
+       than Windows CLR host: the GAC assemblies have the lowest search priority, (see
+       https://www.mono-project.com/docs/advanced/assemblies-and-the-gac/), not the
+       highest as is in Windows (documented at
+       https://docs.microsoft.com/dotnet/framework/deployment/how-the-runtime-locates-assemblies).
+       To run the tests under Mono, we need correct assemblies in the same directory as
+       the test executable. Correct versions are in the MSBuild directory under Mono. -->
+  <ItemGroup Condition=" '$(TargetFramework)' == 'net45' and '$(OS)' != 'Windows_NT' ">
+    <None Include="$(_MSBuildAssemblyPath)/Microsoft.Build.Framework.dll;
+                   $(_MSBuildAssemblyPath)/Microsoft.Build.Utilities.v4.0.dll;
+                   $(_MSBuildAssemblyPath)/Microsoft.Build.Utilities.Core.dll"
+          CopyToOutputDirectory="Always" Visible="false" />
+  </ItemGroup>
+  <PropertyGroup Condition=" '$(TargetFramework)' == 'net45' and '$(OS)' != 'Windows_NT' ">
+    <!-- The None items are included into assembly candidate resolution by default, and
+         we do not want that, as they are not valid as reference assemblies (the version of
+         Microsoft.Build.Utilities.v4.0 is a pure facade for Microsoft.Build.Utilities.Core,
+         and does not define any types at all). Exclude them from assembly resolution. See
+         https://github.com/Microsoft/msbuild/blob/50639058f/documentation/wiki/ResolveAssemblyReference.md -->
+    <AssemblySearchPaths>{HintPathFromItem};{TargetFrameworkDirectory};{RawFileName}</AssemblySearchPaths>
+    <!-- Locate Mono's copy of MSBuild assemblies for cross-build. -->
+    <_MSBuildAssemblyPath Condition=" '$(MSBuildRuntimeType)' == 'Core' "
+                          >$(FrameworkPathOverride)/../msbuild/$(MSBuildToolsVersion)/bin</_MSBuildAssemblyPath>
+    <!-- Use Mono-provided patch for Mono build. -->
+    <_MSBuildAssemblyPath Condition=" '$(MSBuildRuntimeType)' != 'Core' "
+                          >$(MSBuildToolsPath)</_MSBuildAssemblyPath>
+  </PropertyGroup>
+
 </Project>

src/csharp/Grpc.Tools.Tests/NUnitMain.cs

@@ -22,7 +22,7 @@ using NUnitLite;
 namespace Grpc.Tools.Tests {
   static class NUnitMain {
     public static int Main(string[] args) =>
-#if NETCOREAPP1_0
+#if NETCOREAPP1_0 || NETCOREAPP1_1
       new AutoRun(typeof(NUnitMain).GetTypeInfo().Assembly).Execute(args);
 #else
       new AutoRun().Execute(args);

src/csharp/Grpc.Tools.Tests/ProtoCompileCommandLineGeneratorTest.cs

@@ -16,6 +16,7 @@
 
 #endregion
 
+using System.IO;
 using Microsoft.Build.Framework;
 using Moq;
 using NUnit.Framework;
@@ -152,6 +153,8 @@ namespace Grpc.Tools.Tests {
     [TestCase("C:\\"   , "C:\\")]
     [TestCase("C:\\\\" , "C:\\")]
     public void DirectorySlashTrimmingCases(string given, string expect) {
+      if (Path.DirectorySeparatorChar == '/')
+        expect = expect.Replace('\\', '/');
       _task.OutputDir = given;
       ExecuteExpectSuccess();
       Assert.That(_task.LastResponseFile,

src/csharp/Grpc.Tools/Common.cs

@@ -50,7 +50,7 @@ namespace Grpc.Tools {
     public static bool IsWindows => Os == OsKind.Windows;
 
     static Platform() {
-#if NETSTANDARD
+#if NETCORE
       Os = RuntimeInformation.IsOSPlatform(OSPlatform.Windows) ? OsKind.Windows
          : RuntimeInformation.IsOSPlatform(OSPlatform.Linux) ? OsKind.Linux
          : RuntimeInformation.IsOSPlatform(OSPlatform.OSX) ? OsKind.MacOsX

src/csharp/Grpc.Tools/Grpc.Tools.csproj

@@ -14,8 +14,8 @@
        and may not compile Grpc.Core/Version.cs, as that file references constants
        in Grpc.Core.dll.
        TODO(kkm): Refactor imports. -->
-  <PropertyGroup Condition="'$(OS)' != 'Windows_NT'">
-    <!-- Workaround for https://github.com/dotnet/sdk/issues/335 -->
+  <PropertyGroup Condition=" '$(OS)' != 'Windows_NT' and '$(MSBuildRuntimeType)' == 'Core' ">
+    <!-- Use Mono reference assemblies in SDK build: https://github.com/dotnet/sdk/issues/335 -->
     <FrameworkPathOverride Condition="Exists('/usr/lib/mono/4.5-api')">/usr/lib/mono/4.5-api</FrameworkPathOverride>
     <FrameworkPathOverride Condition="Exists('/usr/local/lib/mono/4.5-api')">/usr/local/lib/mono/4.5-api</FrameworkPathOverride>
     <FrameworkPathOverride Condition="Exists('/Library/Frameworks/Mono.framework/Versions/Current/lib/mono/4.5-api')">/Library/Frameworks/Mono.framework/Versions/Current/lib/mono/4.5-api</FrameworkPathOverride>
@@ -27,20 +27,16 @@
     <!-- GPB:  ../src/google/protobuf/ -->
     <Assets_ProtoInclude>../../../third_party/protobuf/src/google/protobuf/</Assets_ProtoInclude>
 
-    <!-- GPB:  protoc\ -->
-    <!-- GRPC: protoc_plugins\protoc_ -->
+    <!-- GPB:  ../protoc/ -->
+    <!-- GRPC: ../protoc_plugins/protoc_ -->
     <Assets_ProtoCompiler>../protoc_plugins/protoc_</Assets_ProtoCompiler>
 
-    <!-- GRPC: protoc_plugins\ -->
+    <!-- GRPC: ../protoc_plugins/ -->
     <Assets_GrpcPlugins>../protoc_plugins/</Assets_GrpcPlugins>
   </PropertyGroup>
 
-  <PropertyGroup>
-    <_NetStandard>False</_NetStandard>
-    <_NetStandard Condition=" $(TargetFramework.StartsWith('netstandard')) or $(TargetFramework.StartsWith('netcore')) ">True</_NetStandard>
-
-    <!-- So we do not hardcode an exact version into #if's. -->
-    <DefineConstants Condition="$(_NetStandard)">$(DefineConstants);NETSTANDARD</DefineConstants>
+  <PropertyGroup Condition=" '$(TargetFramework)' != 'net45' ">
+    <DefineConstants>$(DefineConstants);NETCORE</DefineConstants>
   </PropertyGroup>
 
   <PropertyGroup Label="NuGet package definition" Condition=" '$(Configuration)' == 'Release' ">
@@ -71,29 +67,28 @@ Linux and MacOS. Managed runtime is supplied separately in the Grpc.Core package
     <_Asset PackagePath="build/native/include/google/protobuf/" Include="@(_ProtoAssetName->'$(Assets_ProtoInclude)%(Identity).proto')" />
 
     <!-- TODO(kkm): GPB builds assets into "macosx", GRPC into "macos". -->
-    <_Asset PackagePath="build/native/bin/windows/protoc.exe" Include="$(Assets_ProtoCompiler)windows_x86/protoc.exe" />
-    <_Asset PackagePath="build/native/bin/linux_x86/protoc" Include="$(Assets_ProtoCompiler)linux_x86/protoc" />
-    <_Asset PackagePath="build/native/bin/linux_x64/protoc" Include="$(Assets_ProtoCompiler)linux_x64/protoc" />
-    <_Asset PackagePath="build/native/bin/macosx_x86/protoc" Include="$(Assets_ProtoCompiler)macos_x86/protoc" /> <!-- GPB: macosx-->
-    <_Asset PackagePath="build/native/bin/macosx_x64/protoc" Include="$(Assets_ProtoCompiler)macos_x64/protoc" /> <!-- GPB: macosx-->
+    <_Asset PackagePath="build/native/bin/windows/" Include="$(Assets_ProtoCompiler)windows_x86/protoc.exe" />
+    <_Asset PackagePath="build/native/bin/linux_x86/" Include="$(Assets_ProtoCompiler)linux_x86/protoc" />
+    <_Asset PackagePath="build/native/bin/linux_x64/" Include="$(Assets_ProtoCompiler)linux_x64/protoc" />
+    <_Asset PackagePath="build/native/bin/macosx_x86/" Include="$(Assets_ProtoCompiler)macos_x86/protoc" /> <!-- GPB: macosx-->
+    <_Asset PackagePath="build/native/bin/macosx_x64/" Include="$(Assets_ProtoCompiler)macos_x64/protoc" /> <!-- GPB: macosx-->
 
     <!-- gRPC assets (for Grpc.Tools) -->
-    <_Asset PackagePath="build/native/bin/windows/grpc_csharp_plugin.exe" Include="$(Assets_GrpcPlugins)protoc_windows_x86/grpc_csharp_plugin.exe" />
-    <_Asset PackagePath="build/native/bin/linux_x86/grpc_csharp_plugin" Include="$(Assets_GrpcPlugins)protoc_linux_x86/grpc_csharp_plugin" />
-    <_Asset PackagePath="build/native/bin/linux_x64/grpc_csharp_plugin" Include="$(Assets_GrpcPlugins)protoc_linux_x64/grpc_csharp_plugin" />
-    <_Asset PackagePath="build/native/bin/macosx_x86/grpc_csharp_plugin" Include="$(Assets_GrpcPlugins)protoc_macos_x86/grpc_csharp_plugin" />
-    <_Asset PackagePath="build/native/bin/macosx_x64/grpc_csharp_plugin" Include="$(Assets_GrpcPlugins)protoc_macos_x64/grpc_csharp_plugin" />
+    <_Asset PackagePath="build/native/bin/windows/" Include="$(Assets_GrpcPlugins)protoc_windows_x86/grpc_csharp_plugin.exe" />
+    <_Asset PackagePath="build/native/bin/linux_x86/" Include="$(Assets_GrpcPlugins)protoc_linux_x86/grpc_csharp_plugin" />
+    <_Asset PackagePath="build/native/bin/linux_x64/" Include="$(Assets_GrpcPlugins)protoc_linux_x64/grpc_csharp_plugin" />
+    <_Asset PackagePath="build/native/bin/macosx_x86/" Include="$(Assets_GrpcPlugins)protoc_macos_x86/grpc_csharp_plugin" />
+    <_Asset PackagePath="build/native/bin/macosx_x64/" Include="$(Assets_GrpcPlugins)protoc_macos_x64/grpc_csharp_plugin" />
 
     <None Include="@(_Asset)" Pack="true" Visible="false" />
   </ItemGroup>
 
-  <ItemGroup Condition="!$(_NetStandard)">
-    <Reference Include="Microsoft.Build.Framework" Pack="false" />
-    <Reference Include="Microsoft.Build.Utilities.v4.0" Pack="false" />
+  <ItemGroup Condition=" '$(TargetFramework)' == 'net45' ">
+    <Reference Include="Microsoft.Build.Framework; Microsoft.Build.Utilities.v4.0" Pack="false" />
   </ItemGroup>
 
-  <ItemGroup Condition="$(_NetStandard)">
-    <PackageReference Include="Microsoft.Build.Framework; Microsoft.Build.Utilities.Core" Version="15.6.85" />
+  <ItemGroup Condition=" '$(TargetFramework)' != 'net45' ">
+    <PackageReference Include="Microsoft.Build.Framework; Microsoft.Build.Utilities.Core" Version="15.6.*" />
     <!--  Set PrivateAssets="All" on all items, even those implicitly added,
           so that they do not become dependencies of this package. -->
     <PackageReference Update="@(PackageReference)" PrivateAssets="All" />