1#region Copyright notice and license
2// Protocol Buffers - Google's data interchange format
3// Copyright 2008 Google Inc.  All rights reserved.
4// https://developers.google.com/protocol-buffers/
5//
6// Redistribution and use in source and binary forms, with or without
7// modification, are permitted provided that the following conditions are
8// met:
9//
10//     * Redistributions of source code must retain the above copyright
11// notice, this list of conditions and the following disclaimer.
12//     * Redistributions in binary form must reproduce the above
13// copyright notice, this list of conditions and the following disclaimer
14// in the documentation and/or other materials provided with the
15// distribution.
16//     * Neither the name of Google Inc. nor the names of its
17// contributors may be used to endorse or promote products derived from
18// this software without specific prior written permission.
19//
20// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31#endregion
32
33using NUnit.Framework;
34using System.Diagnostics;
35using System;
36using System.Reflection;
37using System.IO;
38
39namespace Google.Protobuf
40{
41    public class RefStructCompatibilityTest
42    {
43        /// <summary>
44        /// Checks that the generated code can be compiler with an old C# compiler.
45        /// The reason why this test is needed is that even though dotnet SDK projects allow to set LangVersion,
46        /// this setting doesn't accurately simulate compilation with an actual old pre-roslyn C# compiler.
47        /// For instance, the "ref struct" types are only supported by C# 7.2 and higher, but even if
48        /// LangVersion is set low, the roslyn compiler still understands the concept of ref struct
49        /// and silently accepts them. Therefore we try to build the generated code with an actual old C# compiler
50        /// to be able to catch these sort of compatibility problems.
51        /// </summary>
52        [Test]
53        public void GeneratedCodeCompilesWithOldCsharpCompiler()
54        {
55            if (Environment.OSVersion.Platform != PlatformID.Win32NT)
56            {
57                // This tests needs old C# compiler which is only available on Windows. Skipping it on all other platforms.
58                return;
59            }
60
61            var currentAssemblyDir = Path.GetDirectoryName(typeof(RefStructCompatibilityTest).GetTypeInfo().Assembly.Location);
62            var testProtosProjectDir = Path.GetFullPath(Path.Combine(currentAssemblyDir, "..", "..", "..", "..", "Google.Protobuf.Test.TestProtos"));
63            var testProtosOutputDir = (currentAssemblyDir.Contains("bin/Debug/") || currentAssemblyDir.Contains("bin\\Debug\\")) ? "bin\\Debug\\net45" : "bin\\Release\\net45";
64
65            // If "ref struct" types are used in the generated code, compilation with an old compiler will fail with the following error:
66            // "XYZ is obsolete: 'Types with embedded references are not supported in this version of your compiler.'"
67            // We build the code with GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE to avoid the use of ref struct in the generated code.
68            var compatibilityFlag = "-define:GOOGLE_PROTOBUF_REFSTRUCT_COMPATIBILITY_MODE";
69            var sources = "*.cs";  // the generated sources from the TestProtos project
70            var args = $"-langversion:3 -target:library {compatibilityFlag} -reference:{testProtosOutputDir}\\Google.Protobuf.dll -out:{testProtosOutputDir}\\TestProtos.RefStructCompatibilityTest.OldCompiler.dll {sources}";
71            RunOldCsharpCompilerAndCheckSuccess(args, testProtosProjectDir);
72        }
73
74        /// <summary>
75        /// Invoke an old C# compiler in a subprocess and check it finished successful.
76        /// </summary>
77        /// <param name="args"></param>
78        /// <param name="workingDirectory"></param>
79        private void RunOldCsharpCompilerAndCheckSuccess(string args, string workingDirectory)
80        {
81            using (var process = new Process())
82            {
83                // Get the path to the old C# 5 compiler from .NET framework. This approach is not 100% reliable, but works on most machines.
84                // Alternative way of getting the framework path is System.Runtime.InteropServices.RuntimeEnvironment.GetRuntimeDirectory()
85                // but it only works with the net45 target.
86                var oldCsharpCompilerPath = Path.Combine(Environment.GetEnvironmentVariable("WINDIR"), "Microsoft.NET", "Framework", "v4.0.30319", "csc.exe");
87                process.StartInfo.FileName = oldCsharpCompilerPath;
88                process.StartInfo.RedirectStandardOutput = true;
89                process.StartInfo.RedirectStandardError = true;
90                process.StartInfo.UseShellExecute = false;
91                process.StartInfo.Arguments = args;
92                process.StartInfo.WorkingDirectory = workingDirectory;
93
94                process.OutputDataReceived += (sender, e) =>
95                {
96                    if (e.Data != null)
97                    {
98                        Console.WriteLine(e.Data);
99                    }
100                };
101                process.ErrorDataReceived += (sender, e) =>
102                {
103                    if (e.Data != null)
104                    {
105                        Console.WriteLine(e.Data);
106                    }
107                };
108
109                process.Start();
110
111                process.BeginErrorReadLine();
112                process.BeginOutputReadLine();
113
114                process.WaitForExit();
115                Assert.AreEqual(0, process.ExitCode);
116            }
117        }
118    }
119}