src/third_party/WebKit/Source/bindings/scripts/compute_global_objects.py

   1 #!/usr/bin/python
   2 #
   3 # Copyright 2014 The Chromium Authors. All rights reserved.
   4 # Use of this source code is governed by a BSD-style license that can be
   5 # found in the LICENSE file.
   6
   7 """Compute global objects.
   8
   9 Global objects are defined by interfaces with [Global] or [PrimaryGlobal] on
  10 their definition: http://heycam.github.io/webidl/#Global
  11
  12 Design document: http://www.chromium.org/developers/design-documents/idl-build
  13 """
  14
  15 import optparse
  16 import os
  17 import cPickle as pickle
  18 import sys
  19
  20 from utilities import get_file_contents, idl_filename_to_interface_name, get_interface_extended_attributes_from_idl, read_file_to_list, read_pickle_files, write_pickle_file
  21
  22 GLOBAL_EXTENDED_ATTRIBUTES = frozenset([
  23     'Global',
  24     'PrimaryGlobal',
  25 ])
  26
  27
  28 def parse_options():
  29     usage = 'Usage: %prog [options] [GlobalObjectsComponent.pickle]... [GlobalObjects.pickle]'
  30     parser = optparse.OptionParser(usage=usage)
  31     parser.add_option('--idl-files-list', help='file listing IDL files')
  32     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')
  33
  34     options, args = parser.parse_args()
  35
  36     if options.idl_files_list is None:
  37         parser.error('Must specify a file listing IDL files using --idl-files-list.')
  38     if options.write_file_only_if_changed is None:
  39         parser.error('Must specify whether output files are only written if changed using --write-file-only-if-changed.')
  40     options.write_file_only_if_changed = bool(options.write_file_only_if_changed)
  41     if not args:
  42         parser.error('Must specify an output pickle filename as argument, '
  43                      'optionally preceeded by input pickle filenames.')
  44
  45     return options, args
  46
  47
  48 def dict_union(dicts):
  49     return dict((k, v) for d in dicts for k, v in d.iteritems())
  50
  51
  52 def idl_file_to_global_names(idl_filename):
  53     """Returns global names, if any, for an IDL file.
  54
  55     If the [Global] or [PrimaryGlobal] extended attribute is declared with an
  56     identifier list argument, then those identifiers are the interface's global
  57     names; otherwise, the interface has a single global name, which is the
  58     interface's identifier (http://heycam.github.io/webidl/#Global).
  59     """
  60     interface_name = idl_filename_to_interface_name(idl_filename)
  61     full_path = os.path.realpath(idl_filename)
  62     idl_file_contents = get_file_contents(full_path)
  63     extended_attributes = get_interface_extended_attributes_from_idl(idl_file_contents)
  64
  65     global_keys = GLOBAL_EXTENDED_ATTRIBUTES.intersection(
  66         extended_attributes.iterkeys())
  67     if not global_keys:
  68         return
  69     if len(global_keys) > 1:
  70         raise ValueError('The [Global] and [PrimaryGlobal] extended attributes '
  71                          'MUST NOT be declared on the same interface.')
  72     global_key = next(iter(global_keys))
  73
  74     global_value = extended_attributes[global_key]
  75     if global_value:
  76         return global_value.strip('()').split(',')
  77     return [interface_name]
  78
  79
  80 def idl_files_to_interface_name_global_names(idl_files):
  81     """Yields pairs (interface_name, global_names) found in IDL files."""
  82     for idl_filename in idl_files:
  83         interface_name = idl_filename_to_interface_name(idl_filename)
  84         global_names = idl_file_to_global_names(idl_filename)
  85         if global_names:
  86             yield interface_name, global_names
  87
  88
  89 ################################################################################
  90
  91 def main():
  92     options, args = parse_options()
  93     # args = Input1, Input2, ..., Output
  94     output_global_objects_filename = args.pop()
  95     interface_name_global_names = dict_union(
  96         existing_interface_name_global_names
  97         for existing_interface_name_global_names in read_pickle_files(args))
  98
  99     # Input IDL files are passed in a file, due to OS command line length
 100     # limits. This is generated at GYP time, which is ok b/c files are static.
 101     idl_files = read_file_to_list(options.idl_files_list)
 102     interface_name_global_names.update(
 103             idl_files_to_interface_name_global_names(idl_files))
 104
 105     write_pickle_file(output_global_objects_filename,
 106                       interface_name_global_names,
 107                       options.write_file_only_if_changed)
 108
 109
 110 if __name__ == '__main__':
 111     sys.exit(main())