C#: Factor C++ parts out of autobuilder

csharp/autobuilder/Semmle.Autobuild.Shared/Solution.cs

@@ -0,0 +1,92 @@
+using Microsoft.Build.Construction;
+using Microsoft.Build.Exceptions;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.IO;
+using Semmle.Util.Logging;
+
+namespace Semmle.Autobuild.Shared
+{
+    /// <summary>
+    /// A solution file, extension .sln.
+    /// </summary>
+    public interface ISolution : IProjectOrSolution
+    {
+        /// <summary>
+        /// Solution configurations.
+        /// </summary>
+        IEnumerable<SolutionConfigurationInSolution> Configurations { get; }
+
+        /// <summary>
+        /// The default configuration name, e.g. "Release"
+        /// </summary>
+        string DefaultConfigurationName { get; }
+
+        /// <summary>
+        /// The default platform name, e.g. "x86"
+        /// </summary>
+        string DefaultPlatformName { get; }
+
+        /// <summary>
+        /// Gets the "best" tools version for this solution.
+        /// If there are several versions, because the project files
+        /// are inconsistent, then pick the highest/latest version.
+        /// If no tools versions are present, return 0.0.0.0.
+        /// </summary>
+        Version ToolsVersion { get; }
+    }
+
+    /// <summary>
+    /// A solution file on the filesystem, read using Microsoft.Build.
+    /// </summary>
+    class Solution : ProjectOrSolution, ISolution
+    {
+        readonly SolutionFile? solution;
+
+        readonly IEnumerable<Project> includedProjects;
+        public override IEnumerable<IProjectOrSolution> IncludedProjects => includedProjects;
+
+        public IEnumerable<SolutionConfigurationInSolution> Configurations =>
+            solution == null ? Enumerable.Empty<SolutionConfigurationInSolution>() : solution.SolutionConfigurations;
+
+        public string DefaultConfigurationName =>
+            solution == null ? "" : solution.GetDefaultConfigurationName();
+
+        public string DefaultPlatformName =>
+            solution == null ? "" : solution.GetDefaultPlatformName();
+
+        public Solution(Autobuilder builder, string path, bool allowProject) : base(builder, path)
+        {
+            try
+            {
+                solution = SolutionFile.Parse(FullPath);
+            }
+            catch (Exception ex) when (ex is InvalidProjectFileException || ex is FileNotFoundException)
+            {
+                // We allow specifying projects as solutions in lgtm.yml, so model
+                // that scenario as a solution with just that one project
+                if (allowProject)
+                {
+                    includedProjects = new[] { new Project(builder, path) };
+                    return;
+                }
+
+                builder.Log(Severity.Info, $"Unable to read solution file {path}.");
+                includedProjects = new Project[0];
+                return;
+            }
+
+            includedProjects =
+                solution.ProjectsInOrder.
+                Where(p => p.ProjectType == SolutionProjectType.KnownToBeMSBuildFormat).
+                Select(p => builder.Actions.PathCombine(DirectoryName, builder.Actions.PathCombine(p.RelativePath.Split('\\', StringSplitOptions.RemoveEmptyEntries)))).
+                Select(p => new Project(builder, p)).
+                ToArray();
+        }
+
+        IEnumerable<Version> ToolsVersions => includedProjects.Where(p => p.ValidToolsVersion).Select(p => p.ToolsVersion);
+
+        public Version ToolsVersion => ToolsVersions.Any() ? ToolsVersions.Max() : new Version();
+    }
+}