[test-runner] Make test suite loading more robust.

tools/testrunner/local/testsuite.py

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 77 matching lines @@
 class TestSuite(object):
 
   @staticmethod
   def LoadTestSuite(root):
     name = root.split(os.path.sep)[-1]
     f = None
     try:
       (f, pathname, description) = imp.find_module("testcfg", [root])
       module = imp.load_module("testcfg", f, pathname, description)
       return module.GetSuite(name, root)
-    except:

[Michael Achenbach, 2015/11/25 10:06:58]

This caught other errors, but import errors (e.g. all syntax errors in a suite)
and just used the google test suite by default, leading to hard-to-find errors.

+    except ImportError:
       # Use default if no testcfg is present.
       return GoogleTestSuite(name, root)
     finally:
       if f:
         f.close()
 
   def __init__(self, name, root):
     self.name = name  # string
     self.root = root  # string containing path
     self.tests = None  # list of TestCase objects
@@ skipping 223 matching lines @@
     return (testcase.flags + ["--gtest_filter=" + testcase.path] +
             ["--gtest_random_seed=%s" % context.random_seed] +
             ["--gtest_print_time=0"] +
             context.mode_flags)
 
   def _VariantGeneratorFactory(self):
     return StandardVariantGenerator
 
   def shell(self):
     return self.name