Merge pull request #17992 from tamasvajk/binlog/no-compilations

C#: Consider the extraction of empty binlog files acceptable

Author: tamasvajk

csharp/extractor/Semmle.Extraction.CSharp/Extractor/Extractor.cs

@@ -161,7 +161,15 @@ static bool filter(CompilerCall compilerCall)
                 var allCompilationData = reader.ReadAllCompilationData(filter);
                 var allFailed = true;
 
-                logger.LogInfo($"  Found {allCompilationData.Count} compilations in binary log");
+                if (allCompilationData.Count == 0)
+                {
+                    logger.LogWarning("  No compilations found in binary log.");
+                    return ExitCode.Ok;
+                }
+                else
+                {
+                    logger.LogInfo($"  Found {allCompilationData.Count} compilations in binary log");
+                }
 
                 foreach (var compilationData in allCompilationData)
                 {