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#region Copyright notice and license
// Protocol Buffers - Google's data interchange format
// Copyright 2008 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
#endregion
using NUnit.Framework;
using System.Diagnostics;
using System;
using System.Reflection;
using System.IO;
namespace Google.Protobuf
{
public class RefStructCompatibilityTest
{
/// <summary>
/// Checks that the generated code can be compiler with an old C# compiler.
/// The reason why this test is needed is that even though dotnet SDK projects allow to set LangVersion,
/// this setting doesn't accurately simulate compilation with an actual old pre-roslyn C# compiler.
/// For instance, the "ref struct" types are only supported by C# 7.2 and higher, but even if
/// LangVersion is set low, the roslyn compiler still understands the concept of ref struct
/// and silently accepts them. Therefore we try to build the generated code with an actual old C# compiler
/// to be able to catch these sort of compatibility problems.
/// </summary>
[Test]
public void GeneratedCodeCompilesWithOldCsharpCompiler()
{
if (Environment.OSVersion.Platform != PlatformID.Win32NT)
{
// This tests needs old C# compiler which is only available on Windows. Skipping it on all other platforms.
return;
}
var currentAssemblyDir = Path.GetDirectoryName(typeof(RefStructCompatibilityTest).GetTypeInfo().Assembly.Location);
var testProtosProjectDir = Path.GetFullPath(Path.Combine(currentAssemblyDir, "..", "..", "..", "..", "Google.Protobuf.Test.TestProtos"));
var testProtosOutputDir = (currentAssemblyDir.Contains("bin/Debug/") || currentAssemblyDir.Contains("bin\\Debug\\")) ? "bin\\Debug\\net462" : "bin\\Release\\net462";
// If "ref struct" types are used in the generated code, compilation with an old compiler will fail with the following error:
// "XYZ is obsolete: 'Types with embedded references are not supported in this version of your compiler.'"
// We build the code with GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE to avoid the use of ref struct in the generated code.
var compatibilityFlag = "-define:GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE";
var sources = "*.cs"; // the generated sources from the TestProtos project
// We suppress CS1691, which flags a warning for the generated line of
// #pragma warning disable 1591, 0612, 3021, 8981
// because CS8981 is unknown to this version of the compiler.
var args = $"-langversion:3 -nologo -nowarn:1691 -target:library {compatibilityFlag} -reference:{testProtosOutputDir}\\Google.Protobuf.dll -out:{testProtosOutputDir}\\TestProtos.RefStructCompatibilityTest.OldCompiler.dll {sources}";
RunOldCsharpCompilerAndCheckSuccess(args, testProtosProjectDir);
}
/// <summary>
/// Invoke an old C# compiler in a subprocess and check it finished successful.
/// </summary>
/// <param name="args"></param>
/// <param name="workingDirectory"></param>
private void RunOldCsharpCompilerAndCheckSuccess(string args, string workingDirectory)
{
using var process = new Process();
// Get the path to the old C# 5 compiler from .NET framework. This approach is not 100% reliable, but works on most machines.
// Alternative way of getting the framework path is System.Runtime.InteropServices.RuntimeEnvironment.GetRuntimeDirectory()
// but it only works with the net45 target.
var oldCsharpCompilerPath = Path.Combine(Environment.GetEnvironmentVariable("WINDIR"), "Microsoft.NET", "Framework", "v4.0.30319", "csc.exe");
process.StartInfo.FileName = oldCsharpCompilerPath;
process.StartInfo.RedirectStandardOutput = true;
process.StartInfo.RedirectStandardError = true;
process.StartInfo.UseShellExecute = false;
process.StartInfo.Arguments = args;
process.StartInfo.WorkingDirectory = workingDirectory;
process.OutputDataReceived += (sender, e) =>
{
if (e.Data != null)
{
Console.WriteLine(e.Data);
}
};
process.ErrorDataReceived += (sender, e) =>
{
if (e.Data != null)
{
Console.WriteLine(e.Data);
}
};
process.Start();
process.BeginErrorReadLine();
process.BeginOutputReadLine();
process.WaitForExit();
Assert.AreEqual(0, process.ExitCode);
}
}
}