tools/trace: More helpful message when no args are provided.

diff --git a/src/gallium/tools/trace/parse.py b/src/gallium/tools/trace/parse.py
index b08d36867154025693e0728401d1c42a8d5e1ddb..feb0b64e231001bfa6cccded1ae02bdb40bddaa0 100755 (executable)
--- a/src/gallium/tools/trace/parse.py
+++ b/src/gallium/tools/trace/parse.py
@@ -364,23 +364,23 @@ class Main:
         optparser = self.get_optparser()
         (options, args) = optparser.parse_args(sys.argv[1:])
     
-        if args:
-            for arg in args:
-                if arg.endswith('.gz'):
-                    from gzip import GzipFile
-                    stream = GzipFile(arg, 'rt')
-                elif arg.endswith('.bz2'):
-                    from bz2 import BZ2File
-                    stream = BZ2File(arg, 'rU')
-                else:
-                    stream = open(arg, 'rt')
-                self.process_arg(stream, options)
-        else:
+        if not args:
+            optparser.error('insufficient number of arguments')
+
+        for arg in args:
+            if arg.endswith('.gz'):
+                from gzip import GzipFile
+                stream = GzipFile(arg, 'rt')
+            elif arg.endswith('.bz2'):
+                from bz2 import BZ2File
+                stream = BZ2File(arg, 'rU')
+            else:
+                stream = open(arg, 'rt')
             self.process_arg(stream, options)
 
     def get_optparser(self):
         optparser = optparse.OptionParser(
-            usage="\n\t%prog [options] [traces] ...")
+            usage="\n\t%prog [options] TRACE  [...]")
         return optparser
 
     def process_arg(self, stream, options):