quality of life touchups for benchmark script

scripts/benchmark.py

@@ -1,8 +1,10 @@
 #!/usr/bin/python3
 import argparse
 import json
+import os
 import statistics
 import subprocess
+import sys
 
 from monotonic import monotonic
 
@@ -12,6 +14,17 @@
 def main():
     args = get_arguments()
 
+    print(
+        'Running performance tests on: {}'.format(
+            ', '.join(args.plugin),
+        ),
+        file=sys.stderr,
+    )
+    print(
+        'for: {}'.format(args.filenames),
+        file=sys.stderr,
+    )
+
     # First, convert chosen plugins into their disabled flags
     always_disabled_plugins = []
     flag_list = []
@@ -97,7 +110,14 @@ def get_arguments():
 
     args = parser.parse_args()
     if not args.filenames:
-        args.filenames = ['../.']
+        args.filenames = [
+            os.path.realpath(
+                os.path.join(
+                    os.path.dirname(__file__),
+                    '../',
+                ),
+            ),
+        ]
 
     if not args.plugin:
         args.plugin = plugins
@@ -128,7 +148,7 @@ def time_execution(filenames, timeout, num_iterations=1, flags=None):
             scores.append(monotonic() - start_time)
         except subprocess.TimeoutExpired:
             scores.append(timeout)
-    
+
     return statistics.mean(scores)