IDL build: Split global objects computation from global constructors computation

Source/bindings/scripts/generate_global_constructors.py

 #!/usr/bin/python
 #
 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Generates interface properties on global objects.
 
 Concretely these are implemented as "constructor attributes", meaning
 "attributes whose name ends with Constructor" (special-cased by code generator),
 hence "global constructors" for short.
 
 For reference on global objects, see:
 http://heycam.github.io/webidl/#Global
 http://heycam.github.io/webidl/#Exposed
 
 Design document: http://www.chromium.org/developers/design-documents/idl-build
 """
 
 import itertools
 import optparse
 import os
+import cPickle as pickle
 import re
 import sys
 
 from collections import defaultdict
-from utilities import get_file_contents, write_file, get_interface_extended_attributes_from_idl, is_callback_interface_from_idl
+from utilities import get_file_contents, idl_filename_to_interface_name, read_file_to_list, write_file, get_interface_extended_attributes_from_idl, is_callback_interface_from_idl
 
-interface_name_to_global_names = defaultdict(list)
+interface_name_to_global_names = {}
 global_name_to_constructors = defaultdict(list)
 
 
-HEADER_FORMAT = """
-// Stub header file for {{idl_basename}}
+HEADER_FORMAT = """// Stub header file for {{idl_basename}}
 // Required because the IDL compiler assumes that a corresponding header file
 // exists for each IDL file.
 """
 
 def parse_options():
     parser = optparse.OptionParser()
     parser.add_option('--idl-files-list', help='file listing IDL files')
+    parser.add_option('--global-objects-file', help='pickle file of global objects')
     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.idl_files_list is None:
         parser.error('Must specify a file listing IDL files using --idl-files-list.')
+    if options.global_objects_file is None:
+        parser.error('Must specify a pickle file of global objects using --global-objects-file.')
     if options.write_file_only_if_changed is None:
         parser.error('Must specify whether output files are only written if changed using --write-file-only-if-changed.')
     options.write_file_only_if_changed = bool(options.write_file_only_if_changed)
 
     return options, args
 
 
-def interface_to_global_names(interface_name, extended_attributes):
-    """Returns global names, if any, for an interface name.
-
-    If the [Global] or [PrimaryGlobal] extended attribute is declared with an
-    identifier list argument, then those identifiers are the interface's global
-    names; otherwise, the interface has a single global name, which is the
-    interface's identifier (http://heycam.github.io/webidl/#Global).
-    """
-    for key in ['Global', 'PrimaryGlobal']:
-        if key not in extended_attributes:
-            continue
-        global_value = extended_attributes[key]
-        if global_value:
-            # FIXME: In spec names are comma-separated, but that makes parsing very
-            # difficult (https://www.w3.org/Bugs/Public/show_bug.cgi?id=24959).
-            return global_value.split('&')
-        return [interface_name]
-    return []
-
-
 def flatten_list(iterable):
     return list(itertools.chain.from_iterable(iterable))
 
 
 def interface_name_to_constructors(interface_name):
     """Returns constructors for an interface."""
     global_names = interface_name_to_global_names[interface_name]
     return flatten_list(global_name_to_constructors[global_name]
                         for global_name in global_names)
 
 
 def record_global_constructors(idl_filename):
-    interface_name, _ = os.path.splitext(os.path.basename(idl_filename))
+    interface_name = idl_filename_to_interface_name(idl_filename)
     full_path = os.path.realpath(idl_filename)
     idl_file_contents = get_file_contents(full_path)
     extended_attributes = get_interface_extended_attributes_from_idl(idl_file_contents)
 
     # An interface property is produced for every non-callback interface
     # that does not have [NoInterfaceObject].
     # Callback interfaces with constants also have interface properties,
     # but there are none of these in Blink.
     # http://heycam.github.io/webidl/#es-interfaces
     if (is_callback_interface_from_idl(idl_file_contents) or
         'NoInterfaceObject' in extended_attributes):
         return
 
-    # Check if interface has [Global] / [PrimaryGlobal] extended attributes.
-    interface_name_to_global_names[interface_name] = interface_to_global_names(interface_name, extended_attributes)
-
     # The [Exposed] extended attribute MUST take an identifier list. Each
     # identifier in the list MUST be a global name. An interface or interface
     # member the extended attribute applies to will be exposed only on objects
     # associated with ECMAScript global environments whose global object
     # implements an interface that has a matching global name.
     # FIXME: In spec names are comma-separated, but that makes parsing very
     # difficult (https://www.w3.org/Bugs/Public/show_bug.cgi?id=24959).
     exposed_global_names = extended_attributes.get('Exposed', 'Window').split('&')
     new_constructors_list = generate_global_constructors_list(interface_name, extended_attributes)
     for exposed_global_name in exposed_global_names:
@@ skipping 43 matching lines @@
                header_filename, only_if_changed)
 
 
 ################################################################################
 
 def main():
     options, args = parse_options()
 
     # Input IDL files are passed in a file, due to OS command line length
     # limits. This is generated at GYP time, which is ok b/c files are static.
-    with open(options.idl_files_list) as idl_files_list:
-        idl_files = [line.rstrip('\n') for line in idl_files_list]
+    idl_files = read_file_to_list(options.idl_files_list)
 
     # Output IDL files (to generate) are passed at the command line, since
     # these are in the build directory, which is determined at build time, not
     # GYP time.
     # These are passed as pairs of GlobalObjectName, GlobalObject.idl
     interface_name_idl_filename = [(args[i], args[i + 1])
                                    for i in range(0, len(args), 2)]
 
+    with open(options.global_objects_file) as global_objects_file:
+        interface_name_to_global_names.update(pickle.load(global_objects_file))
+
     for idl_filename in idl_files:
         record_global_constructors(idl_filename)
 
     # Check for [Exposed] / [Global] mismatch.
-    known_global_names = set(itertools.chain.from_iterable(interface_name_to_global_names.values()))
-    unknown_global_names = set(global_name_to_constructors).difference(known_global_names)
-    if unknown_global_names:
+    known_global_names = frozenset(itertools.chain.from_iterable(interface_name_to_global_names.values()))
+    exposed_global_names = frozenset(global_name_to_constructors)
+    if not exposed_global_names.issubset(known_global_names):
+        unknown_global_names = exposed_global_names.difference(known_global_names)
         raise ValueError('The following global names were used in '
                          '[Exposed=xxx] but do not match any [Global] / '
                          '[PrimaryGlobal] interface: %s'
                          % list(unknown_global_names))
 
     # Write partial interfaces containing constructor attributes for each
     # global interface.
     for interface_name, idl_filename in interface_name_idl_filename:
         constructors = interface_name_to_constructors(interface_name)
         write_global_constructors_partial_interface(
             interface_name,
             idl_filename,
             constructors,
             options.write_file_only_if_changed)
 
 
 if __name__ == '__main__':
     sys.exit(main())