DWIMy filterspecs for dotest.py

[lawrence_danna]

Summary

dotest.py currently requires a filterspec to be of the
form TestCase.test_method. This patch makes it more
flexible, so you can pass TestModule.TestCase.test_method
or TestModule.TestCase or TestCase.test_method or just
test_method.

This makes it more convenient to just copy a test name
out of the terminal after running a bunch of tests and use
it as a filterspec.

[labath]

Sounds reasonable to me. The existing filtering method was indeed quite tricky to use. Does anyone else have any opinions on this?

[labath]

(Also, the documentation for the -f option should be updated to reflect the new functionality.)

[jingham]

This is great, and will make the -f option much easier to use.

[lawrence_danna]

updated help text

[JDevlieghere]

Thanks!

lldb/packages/Python/lldbsuite/test/dotest.py

def visit_file(dir, name):
 
     # Update the sys.path first.
     if not sys.path.count(dir):
         sys.path.insert(0, dir)
     base = os.path.splitext(name)[0]
 
     # Thoroughly check the filterspec against the base module and admit
     # the (base, filterspec) combination only when it makes sense.
-    filterspec = None
-    for filterspec in configuration.filters:
-        # Optimistically set the flag to True.
-        filtered = True
-        module = __import__(base)
-        parts = filterspec.split('.')
-        obj = module
+
+    def check(obj, parts):
         for part in parts:
             try:
                 parent, obj = obj, getattr(obj, part)
             except AttributeError:
                 # The filterspec has failed.
-                filtered = False
-                break
+                return False
+        return True
 
-        # If filtered, we have a good filterspec.  Add it.
-        if filtered:
-            # print("adding filter spec %s to module %s" % (filterspec, module))
-            configuration.suite.addTests(
-                unittest2.defaultTestLoader.loadTestsFromName(
-                    filterspec, module))
-            continue
+    module = __import__(base)
+
+    def iter_filters():
+        for filterspec in configuration.filters:
+            parts = filterspec.split('.')
+            if check(module, parts):
+                yield filterspec
+            elif parts[0] == base and len(parts) > 1 and check(module, parts[1:]):
+                yield '.'.join(parts[1:])
+            else:
+                for key,value in module.__dict__.items():
+                    if check(value, parts):
+                        yield key + '.' + filterspec
+
+    filtered = False
+    for filterspec in iter_filters():
+        filtered = True
+        print("adding filter spec %s to module %s" % (filterspec, repr(module)))
+        tests = unittest2.defaultTestLoader.loadTestsFromName(filterspec, module)
+        configuration.suite.addTests(tests)
 
     # Forgo this module if the (base, filterspec) combo is invalid
     if configuration.filters and not filtered:
         return
 
-    if not filterspec or not filtered:
+    if not filtered:
         # Add the entire file's worth of tests since we're not filtered.
         # Also the fail-over case when the filterspec branch
         # (base, filterspec) combo doesn't make sense.
         configuration.suite.addTests(
             unittest2.defaultTestLoader.loadTestsFromName(base))
 
 
 def visit(prefix, dir, names):

lldb/packages/Python/lldbsuite/test/dotest_args.py

def create_parser():
     group.add_argument('--filecheck', metavar='filecheck', dest='filecheck', help=textwrap.dedent('Specify which FileCheck binary to use.'))
 
     # Test filtering options
     group = parser.add_argument_group('Test filtering options')
     group.add_argument(
         '-f',
         metavar='filterspec',
         action='append',
-        help='Specify a filter, which consists of the test class name, a dot, followed by the test method, to only admit such test into the test suite')  # FIXME: Example?
+        help=('Specify a filter, which looks like "TestModule.TestClass.test_name".  '+
+            'You may also use shortened filters, such as '+
+            '"TestModule.TestClass", "TestClass.test_name", or just "test_name".'))
     group.add_argument(
         '-p',
         metavar='pattern',
         help='Specify a regexp filename pattern for inclusion in the test suite')
     group.add_argument('--excluded', metavar='exclusion-file', action='append', help=textwrap.dedent(
         '''Specify a file for tests to exclude. File should contain lists of regular expressions for test files or methods,
                                 with each list under a matching header (xfail files, xfail methods, skip files, skip methods)'''))
     group.add_argument(