Clean up generate_event_interfaces.py

Source/bindings/scripts/generate_event_interfaces.py

 #!/usr/bin/python
 #
 # Copyright (C) 2013 Google Inc. 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.
@@ skipping 16 matching lines @@
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 """Generate event interfaces .in file (EventInterfaces.in).
 
 The event interfaces .in file contains a list of all Event interfaces, i.e.,
 all interfaces that inherit from Event, including Event itself,
 together with certain extended attributes.
 
+Paths are in POSIX format, and relative to Source/.
+
 This list is used in core/ to generate EventFactory and EventNames.
 The .in format is documented in build/scripts/in_file.py.
 """
 
-import optparse
+from optparse import OptionParser
 import cPickle as pickle
 import os
 import posixpath
 import sys
 
 from utilities import get_file_contents, write_file, get_interface_extended_attributes_from_idl
 
-interfaces_info = {}
-extended_attributes_by_interface = {}  # interface name -> extended attributes
+EXPORTED_EXTENDED_ATTRIBUTES = (
+    'Conditional',
+    'ImplementedAs',
+    'RuntimeEnabled',
+)
+module_path = os.path.dirname(os.path.realpath(__file__))
+source_dir = os.path.normpath(os.path.join(module_path, os.pardir, os.pardir))
 
 
 def parse_options():
-    parser = optparse.OptionParser()
-    parser.add_option('--event-names-file', help='output file')
+    parser = OptionParser()
+    parser.add_option('--event-interfaces-file', help='output file')
     parser.add_option('--interfaces-info-file', help='output pickle file')
     parser.add_option('--write-file-only-if-changed', type='int', help='if true, do not write an output file if it would be identical to the existing one, which avoids unnecessary rebuilds in ninja')
 
     options, args = parser.parse_args()
-    if options.event_names_file is None:
-        parser.error('Must specify an output file using --event-names-file.')
+    if options.event_interfaces_file is None:
+        parser.error('Must specify an output file using --event-interfaces-file.')
     if options.interfaces_info_file is None:
         parser.error('Must specify an input file using --interfaces-info-file.')
     if options.write_file_only_if_changed is None:
         parser.error('Must specify whether file is only written if changed using --write-file-only-if-changed.')
     options.write_file_only_if_changed = bool(options.write_file_only_if_changed)
     if args:
         parser.error('No arguments allowed, but %d given.' % len(args))
     return options
 
 
-def store_event_extended_attributes():
+def write_event_interfaces_file(interfaces_info, destination_filename, only_if_changed):
+    # Event interfaces are interfaces that inherit from Event, and Event itself
     event_interfaces = set(
         interface_name
         for interface_name, interface_info in interfaces_info.iteritems()
         if (interface_name == 'Event' or
             ('ancestors' in interface_info and
              interface_info['ancestors'][-1] == 'Event')))
-    for interface_name in event_interfaces:
-        interface_info = interfaces_info[interface_name]
-        idl_file_contents = get_file_contents(interface_info['full_path'])
-        extended_attributes_by_interface[interface_name] = get_interface_extended_attributes_from_idl(idl_file_contents)
 
-
-def write_event_names_file(destination_filename, only_if_changed):
-    event_names = set(
-        interface_name
-        for interface_name, interface_info in interfaces_info.iteritems()
-        if (interface_name == 'Event' or
-            ('ancestors' in interface_info and
-             interface_info['ancestors'][-1] == 'Event')))
-
-    def extended_attribute_string(name):
-        value = extended_attributes[name]
+    def extended_attribute_string(name, value):
         if name == 'RuntimeEnabled':
             value += 'Enabled'
         return name + '=' + value
 
-    source_dir, _ = os.path.split(os.getcwd())
-    lines = []
-    lines.append('namespace="Event"\n')
-    lines.append('\n')
-    for filename, extended_attributes in sorted(
-        (interface_info['full_path'],
-         extended_attributes_by_interface[interface_name])
-        for interface_name, interface_info in interfaces_info.iteritems()
-        if interface_name in event_names):
-        refined_filename, _ = os.path.splitext(os.path.relpath(filename, source_dir))
-        refined_filename = refined_filename.replace(os.sep, posixpath.sep)
+    def interface_line(interface_name):
+        full_path = interfaces_info[interface_name]['full_path']
+
+        relative_path_local, _ = os.path.splitext(os.path.relpath(full_path, source_dir))
+        relative_path_posix = relative_path_local.replace(os.sep, posixpath.sep)
+
+        idl_file_contents = get_file_contents(full_path)
+        extended_attributes = get_interface_extended_attributes_from_idl(idl_file_contents)
         extended_attributes_list = [
-            extended_attribute_string(name)
-            for name in 'Conditional', 'ImplementedAs', 'RuntimeEnabled'
+            extended_attribute_string(name, extended_attributes[name])
+            for name in EXPORTED_EXTENDED_ATTRIBUTES
             if name in extended_attributes]
-        lines.append('%s %s\n' % (refined_filename, ', '.join(extended_attributes_list)))
+
+        return '%s %s\n' % (relative_path_posix,
+                            ', '.join(extended_attributes_list))
+
+    lines = ['namespace="Event"\n',
+             '\n']
+    interface_lines = [interface_line(interface_name)
+                       for interface_name in event_interfaces]
+    interface_lines.sort()
+    lines.extend(interface_lines)
     write_file(lines, destination_filename, only_if_changed)
 
 
 ################################################################################
 
 def main():
     options = parse_options()
     with open(options.interfaces_info_file) as interfaces_info_file:
-        interfaces_info.update(pickle.load(interfaces_info_file))
-    store_event_extended_attributes()
-    write_event_names_file(options.event_names_file,
-                           options.write_file_only_if_changed)
+        interfaces_info = pickle.load(interfaces_info_file)
+    write_event_interfaces_file(interfaces_info,
+                                options.event_interfaces_file,
+                                options.write_file_only_if_changed)
 
 
 if __name__ == '__main__':
     sys.exit(main())