C#: Move autobuilder into separate folder

csharp/autobuilder/Semmle.Autobuild/Project.cs

@@ -0,0 +1,69 @@
+using System;
+using System.IO;
+using System.Xml;
+using Semmle.Util.Logging;
+
+namespace Semmle.Autobuild
+{
+    /// <summary>
+    /// Representation of a .csproj (C#) or .vcxproj (C++) file.
+    /// C# project files come in 2 flavours, .Net core and msbuild, but they
+    /// have the same file extension.
+    /// </summary>
+    public class Project
+    {
+        /// <summary>
+        /// Holds if this project is for .Net core.
+        /// </summary>
+        public bool DotNetProject { get; private set; }
+
+        public bool ValidToolsVersion { get; private set; }
+
+        public Version ToolsVersion { get; private set; }
+
+        readonly string filename;
+
+        public Project(Autobuilder builder, string filename)
+        {
+            this.filename = filename;
+            ToolsVersion = new Version();
+
+            if (!File.Exists(filename))
+                return;
+
+            var projFile = new XmlDocument();
+            projFile.Load(filename);
+            var root = projFile.DocumentElement;
+
+            if (root.Name == "Project")
+            {
+                if (root.HasAttribute("Sdk"))
+                {
+                    DotNetProject = true;
+                }
+                else
+                {
+                    var toolsVersion = root.GetAttribute("ToolsVersion");
+                    if (string.IsNullOrEmpty(toolsVersion))
+                    {
+                        builder.Log(Severity.Warning, "Project {0} is missing a tools version", filename);
+                    }
+                    else
+                    {
+                        try
+                        {
+                            ToolsVersion = new Version(toolsVersion);
+                            ValidToolsVersion = true;
+                        }
+                        catch   // Generic catch clause - Version constructor throws about 5 different exceptions.
+                        {
+                            builder.Log(Severity.Warning, "Project {0} has invalid tools version {1}", filename, toolsVersion);
+                        }
+                    }
+                }
+            }
+        }
+
+        public override string ToString() => filename;
+    }
+}