[bindings] partial interfaces should not violate componentization

Source/bindings/scripts/idl_compiler.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.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 34 matching lines @@
 
 def parse_options():
     parser = OptionParser()
     parser.add_option('--cache-directory',
                       help='cache directory, defaults to output directory')
     parser.add_option('--generate-dictionary-impl',
                       action="store_true", default=False)
     parser.add_option('--output-directory')
     parser.add_option('--interfaces-info-file')
     parser.add_option('--write-file-only-if-changed', type='int')
+    # FIXME: We should always explicitly specify --target-component and
+    # remove the default behavior.
+    parser.add_option('--target-component',
+                      help='target component to generate code, defaults to '
+                      'component of input idl file')
     # ensure output comes last, so command line easy to parse via regexes
     parser.disable_interspersed_args()
 
     options, args = parser.parse_args()
     if options.output_directory is None:
         parser.error('Must specify output directory using --output-directory.')
     options.write_file_only_if_changed = bool(options.write_file_only_if_changed)
     if len(args) != 1:
         parser.error('Must specify exactly 1 input file as argument, but %d given.' % len(args))
     idl_filename = os.path.realpath(args[0])
@@ skipping 11 matching lines @@
 
     In concrete classes:
     * self.code_generator must be set, implementing generate_code()
       (returning a list of output code), and
     * compile_file() must be implemented (handling output filenames).
     """
     __metaclass__ = abc.ABCMeta
 
     def __init__(self, output_directory, cache_directory='',
                  code_generator=None, interfaces_info=None,
-                 interfaces_info_filename='', only_if_changed=False):
+                 interfaces_info_filename='', only_if_changed=False,
+                 target_component=None):
         """
         Args:
             interfaces_info:
                 interfaces_info dict
                 (avoids auxiliary file in run-bindings-tests)
             interfaces_info_file: filename of pickled interfaces_info
         """
         cache_directory = cache_directory or output_directory
         self.cache_directory = cache_directory
         self.code_generator = code_generator
         if interfaces_info_filename:
             with open(interfaces_info_filename) as interfaces_info_file:
                 interfaces_info = pickle.load(interfaces_info_file)
         self.interfaces_info = interfaces_info
         self.only_if_changed = only_if_changed
         self.output_directory = output_directory
+        self.target_component = target_component
         self.reader = IdlReader(interfaces_info, cache_directory)
 
     def compile_and_write(self, idl_filename):
         interface_name = idl_filename_to_interface_name(idl_filename)
-        component = idl_filename_to_component(idl_filename)
         definitions = self.reader.read_idl_definitions(idl_filename)
+        target_component = self.target_component or idl_filename_to_component(idl_filename)
+        target_definitions = definitions[target_component]
         output_code_list = self.code_generator.generate_code(
-            definitions[component], interface_name)
+            target_definitions, interface_name)
         for output_path, output_code in output_code_list:
             write_file(output_code, output_path, self.only_if_changed)
 
     @abc.abstractmethod
     def compile_file(self, idl_filename):
         pass
 
 
 class IdlCompilerV8(IdlCompiler):
     def __init__(self, *args, **kwargs):
@@ skipping 14 matching lines @@
 
     def compile_file(self, idl_filename):
         self.compile_and_write(idl_filename)
 
 
 def generate_bindings(options, input_filename):
     idl_compiler = IdlCompilerV8(
         options.output_directory,
         cache_directory=options.cache_directory,
         interfaces_info_filename=options.interfaces_info_file,
-        only_if_changed=options.write_file_only_if_changed)
+        only_if_changed=options.write_file_only_if_changed,
+        target_component=options.target_component)
     idl_compiler.compile_file(input_filename)
 
 
 def generate_dictionary_impl(options, input_filename):
     idl_compiler = IdlCompilerDictionaryImpl(
         options.output_directory,
         cache_directory=options.cache_directory,
         interfaces_info_filename=options.interfaces_info_file,
         only_if_changed=options.write_file_only_if_changed)
 
     idl_filenames = read_idl_files_list_from_file(input_filename)
     for idl_filename in idl_filenames:
         idl_compiler.compile_file(idl_filename)
 
 
 def main():
     options, input_filename = parse_options()
     if options.generate_dictionary_impl:
         # |input_filename| should be a file which contains a list of IDL
         # dictionary paths.
         generate_dictionary_impl(options, input_filename)
     else:
         # |input_filename| should be a path of an IDL file.
         generate_bindings(options, input_filename)
 
 
 if __name__ == '__main__':
     sys.exit(main())