C#: Add flag to Standalone extractor to use the self contained .Net framework (#4233)

csharp/extractor/Semmle.Extraction.CSharp.Standalone/BuildAnalysis.cs

@@ -88,7 +88,7 @@ namespace Semmle.BuildAnalyser
                     nuget = new NugetPackages(sourceDir.FullName, PackageDirectory);
                     ReadNugetFiles();
                 }
-                catch(FileNotFoundException)
+                catch (FileNotFoundException)
                 {
                     progressMonitor.MissingNuGet();
                 }
@@ -97,7 +97,9 @@ namespace Semmle.BuildAnalyser
             // Find DLLs in the .Net Framework
             if (options.ScanNetFrameworkDlls)
             {
-                dllDirNames.Add(Runtime.Runtimes.First());
+                var runtimeLocation = Runtime.GetRuntime(options.UseSelfContainedDotnet);
+                progressMonitor.Log(Util.Logging.Severity.Debug, $"Runtime location selected: {runtimeLocation}");
+                dllDirNames.Add(runtimeLocation);
             }
 
             // These files can sometimes prevent `dotnet restore` from working correctly.
@@ -279,7 +281,7 @@ namespace Semmle.BuildAnalyser
 
         void AnalyseProject(FileInfo project)
         {
-            if(!project.Exists)
+            if (!project.Exists)
             {
                 progressMonitor.MissingProject(project.FullName);
                 return;
@@ -323,7 +325,7 @@ namespace Semmle.BuildAnalyser
         void Restore(string projectOrSolution)
         {
             int exit = DotNet.RestoreToDirectory(projectOrSolution, PackageDirectory.DirInfo.FullName);
-            switch(exit)
+            switch (exit)
             {
                 case 0:
                 case 1:
@@ -342,7 +344,7 @@ namespace Semmle.BuildAnalyser
 
         public void AnalyseSolutions(IEnumerable<string> solutions)
         {
-            Parallel.ForEach(solutions, new ParallelOptions { MaxDegreeOfParallelism = 4 } , solutionFile =>
+            Parallel.ForEach(solutions, new ParallelOptions { MaxDegreeOfParallelism = 4 }, solutionFile =>
             {
                 try
                 {

csharp/extractor/Semmle.Extraction.CSharp.Standalone/Options.cs

@@ -13,7 +13,7 @@ namespace Semmle.Extraction.CSharp.Standalone
     {
         public override bool handleFlag(string key, bool value)
         {
-            switch(key)
+            switch (key)
             {
                 case "silent":
                     Verbosity = value ? Verbosity.Off : Verbosity.Info;
@@ -36,6 +36,9 @@ namespace Semmle.Extraction.CSharp.Standalone
                 case "skip-dotnet":
                     ScanNetFrameworkDlls = !value;
                     return true;
+                case "self-contained-dotnet":
+                    UseSelfContainedDotnet = value;
+                    return true;
                 default:
                     return base.handleFlag(key, value);
             }
@@ -43,7 +46,7 @@ namespace Semmle.Extraction.CSharp.Standalone
 
         public override bool handleOption(string key, string value)
         {
-            switch(key)
+            switch (key)
             {
                 case "exclude":
                     Excludes.Add(value);
@@ -134,6 +137,11 @@ namespace Semmle.Extraction.CSharp.Standalone
         /// </summary>
         public bool Help = false;
 
+        /// <summary>
+        /// Whether to use the packaged dotnet runtime.
+        /// </summary>
+        public bool UseSelfContainedDotnet = false;
+
         /// <summary>
         /// Determine whether the given path should be excluded.
         /// </summary>
@@ -162,6 +170,7 @@ namespace Semmle.Extraction.CSharp.Standalone
             output.WriteLine("    --threads:nnn    Specify number of threads (default=CPU cores)");
             output.WriteLine("    --verbose        Produce more output");
             output.WriteLine("    --pdb            Cross-reference information from PDBs where available");
+            output.WriteLine("    --self-contained-dotnet    Use the .Net Framework packaged with the extractor");
         }
 
         private Options()

csharp/extractor/Semmle.Extraction.CSharp.Standalone/ProgressMonitor.cs

@@ -16,7 +16,7 @@ namespace Semmle.BuildAnalyser
         void NugetInstall(string package);
         void ResolvedReference(string filename);
         void Summary(int existingSources, int usedSources, int missingSources, int references, int unresolvedReferences, int resolvedConflicts, int totalProjects, int failedProjects, TimeSpan analysisTime);
-        void Warning(string message);
+        void Log(Severity severity, string message);
         void ResolvedConflict(string asm1, string asm2);
         void MissingProject(string projectFile);
         void CommandFailed(string exe, string arguments, int exitCode);
@@ -93,9 +93,9 @@ namespace Semmle.BuildAnalyser
             logger.Log(Severity.Info, "Build analysis completed in {0}", analysisTime);
         }
 
-        public void Warning(string message)
+        public void Log(Severity severity, string message)
         {
-            logger.Log(Severity.Warning, message);
+            logger.Log(severity, message);
         }
 
         public void ResolvedConflict(string asm1, string asm2)

csharp/extractor/Semmle.Extraction.CSharp.Standalone/Runtime.cs

@@ -17,7 +17,7 @@ namespace Semmle.Extraction.CSharp.Standalone
         /// <summary>
         /// Locates .NET Core Runtimes.
         /// </summary>
-        public static IEnumerable<string> CoreRuntimes
+        private static IEnumerable<string> CoreRuntimes
         {
             get
             {
@@ -37,7 +37,7 @@ namespace Semmle.Extraction.CSharp.Standalone
         /// Locates .NET Desktop Runtimes.
         /// This includes Mono and Microsoft.NET.
         /// </summary>
-        public static IEnumerable<string> DesktopRuntimes
+        private static IEnumerable<string> DesktopRuntimes
         {
             get
             {
@@ -63,7 +63,12 @@ namespace Semmle.Extraction.CSharp.Standalone
             }
         }
 
-        public static IEnumerable<string> Runtimes
+        /// <summary>
+        /// Gets the .NET runtime location to use for extraction
+        /// </summary>
+        public static string GetRuntime(bool useSelfContained) => useSelfContained ? ExecutingRuntime : Runtimes.First();
+
+        private static IEnumerable<string> Runtimes
         {
             get
             {