Report projects incompatible with .NET Core

Author: mbg

csharp/autobuilder/Semmle.Autobuild.CSharp/CSharpAutobuilder.cs

@@ -31,6 +31,8 @@ public CSharpAutobuildOptions(IBuildActions actions) : base(actions)
 
     public class CSharpAutobuilder : Autobuilder<CSharpAutobuildOptions>
     {
+        private DotNetRule? dotNetRule;
+
         private BuildCommandAutoRule? buildCommandAutoRule;
 
         public CSharpAutobuilder(IBuildActions actions, CSharpAutobuildOptions options) : base(actions, options) { }
@@ -103,11 +105,12 @@ BuildScript IntermediateAttempt(BuildScript s) =>
                         (s & CheckExtractorRun(false)) |
                         (attemptExtractorCleanup & BuildScript.Failure);
 
+                    this.dotNetRule = new DotNetRule();
                     this.buildCommandAutoRule = new BuildCommandAutoRule(DotNetRule.WithDotNet);
 
                     attempt =
                         // First try .NET Core
-                        IntermediateAttempt(new DotNetRule().Analyse(this, true)) |
+                        IntermediateAttempt(dotNetRule.Analyse(this, true)) |
                         // Then MSBuild
                         (() => IntermediateAttempt(new MsBuildRule().Analyse(this, true))) |
                         // And finally look for a script that might be a build script
@@ -164,6 +167,13 @@ protected override void AutobuildFailureDiagnostic()
 
                 Diagnostic(message);
             }
+            else if (dotNetRule is not null && dotNetRule.NotDotNetProjects.Any())
+            {
+                var message = MakeDiagnostic("dotnet-incompatible-projects", "Some projects are incompatible with .NET Core");
+                message.MarkdownMessage =
+                    "CodeQL found some projects which cannot be built with .NET Core:\n" +
+                    string.Join('\n', dotNetRule.NotDotNetProjects.Select(p => $"- `{p.FullPath}`"));
+                message.Severity = DiagnosticMessage.TspSeverity.Warning;
 
                 Diagnostic(message);
             }

csharp/autobuilder/Semmle.Autobuild.CSharp/DotNetRule.cs

@@ -15,17 +15,34 @@ namespace Semmle.Autobuild.CSharp
     /// </summary>
     internal class DotNetRule : IBuildRule<CSharpAutobuildOptions>
     {
+        private IEnumerable<Project<CSharpAutobuildOptions>> notDotNetProjects;
+
+        /// <summary>
+        /// A list of projects which are incompatible with DotNet.
+        /// </summary>
+        public IEnumerable<Project<CSharpAutobuildOptions>> NotDotNetProjects
+        {
+            get { return this.notDotNetProjects; }
+        }
+
+        public DotNetRule()
+        {
+            this.notDotNetProjects = new List<Project<CSharpAutobuildOptions>>();
+        }
+
         public BuildScript Analyse(IAutobuilder<CSharpAutobuildOptions> builder, bool auto)
         {
             if (!builder.ProjectsOrSolutionsToBuild.Any())
                 return BuildScript.Failure;
 
             if (auto)
             {
-                var notDotNetProject = builder.ProjectsOrSolutionsToBuild
+                notDotNetProjects = builder.ProjectsOrSolutionsToBuild
                     .SelectMany(p => Enumerators.Singleton(p).Concat(p.IncludedProjects))
                     .OfType<Project<CSharpAutobuildOptions>>()
-                    .FirstOrDefault(p => !p.DotNetProject);
+                    .Where(p => !p.DotNetProject);
+                var notDotNetProject = notDotNetProjects.FirstOrDefault();
+
                 if (notDotNetProject is not null)
                 {
                     builder.Log(Severity.Info, "Not using .NET Core because of incompatible project {0}", notDotNetProject);