Merge pull request #16312 from tamasvajk/fix/buildless/file-lookup

C#: Fix `global.json` and `packages.config` lookup

Author: tamasvajk

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DotNet.cs

@@ -143,7 +143,7 @@ private static BuildScript DownloadDotNet(IBuildActions actions, ILogger logger,
             // See https://docs.microsoft.com/en-us/dotnet/core/tools/global-json
             var versions = new List<string>();
 
-            foreach (var path in files.Where(p => p.EndsWith("global.json", StringComparison.Ordinal)))
+            foreach (var path in files.Where(p => string.Equals(FileUtils.SafeGetFileName(p, logger), "global.json", StringComparison.OrdinalIgnoreCase)))
             {
                 try
                 {

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/FileContent.cs

@@ -184,7 +184,7 @@ private void DoInitialize()
             {
                 try
                 {
-                    var isPackagesConfig = file.EndsWith("packages.config", StringComparison.OrdinalIgnoreCase);
+                    var isPackagesConfig = string.Equals(FileUtils.SafeGetFileName(file, logger), "packages.config", StringComparison.OrdinalIgnoreCase);
 
                     foreach (ReadOnlySpan<char> line in unsafeFileReader.ReadLines(file))
                     {

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/SourceGenerators/DotnetSourceGeneratorBase.cs

@@ -55,7 +55,7 @@ protected override IEnumerable<string> Run()
 
             // group additional files by closes project file:
             var projects = fileProvider.Projects
-                .Select(p => (File: p, Directory: SafeGetDirectoryName(p)))
+                .Select(p => (File: p, Directory: FileUtils.SafeGetDirectoryName(p, logger)))
                 .Where(p => p.Directory.Length > 0);
 
             var groupedFiles = new Dictionary<string, List<string>>();
@@ -93,30 +93,6 @@ protected override IEnumerable<string> Run()
             }
         }
 
-        private string SafeGetDirectoryName(string fileName)
-        {
-            try
-            {
-                var dir = Path.GetDirectoryName(fileName);
-                if (dir is null)
-                {
-                    return "";
-                }
-
-                if (!dir.EndsWith(Path.DirectorySeparatorChar))
-                {
-                    dir += Path.DirectorySeparatorChar;
-                }
-
-                return dir;
-            }
-            catch (Exception ex)
-            {
-                logger.LogDebug($"Failed to get directory name for {fileName}: {ex.Message}");
-                return "";
-            }
-        }
-
         protected abstract ICollection<string> AdditionalFiles { get; }
 
         protected abstract string FileType { get; }

csharp/extractor/Semmle.Util/FileUtils.cs

@@ -185,5 +185,42 @@ public static FileInfo CreateTemporaryFile(string extension, out bool shouldClea
 
             return new FileInfo(outputPath);
         }
+
+        public static string SafeGetDirectoryName(string path, ILogger logger)
+        {
+            try
+            {
+                var dir = Path.GetDirectoryName(path);
+                if (dir is null)
+                {
+                    return "";
+                }
+
+                if (!dir.EndsWith(Path.DirectorySeparatorChar))
+                {
+                    dir += Path.DirectorySeparatorChar;
+                }
+
+                return dir;
+            }
+            catch (Exception ex)
+            {
+                logger.LogDebug($"Failed to get directory name for {path}: {ex.Message}");
+                return "";
+            }
+        }
+
+        public static string? SafeGetFileName(string path, ILogger logger)
+        {
+            try
+            {
+                return Path.GetFileName(path);
+            }
+            catch (Exception ex)
+            {
+                logger.LogDebug($"Failed to get file name for {path}: {ex.Message}");
+                return null;
+            }
+        }
     }
 }