Enable the WebIDL [Exposed] annotation on an interface's members.

Source/bindings/scripts/v8_utilities.py

 # 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
 # copyright notice, this list of conditions and the following disclaimer
@@ skipping 56 matching lines @@
     return any(extended_attribute in definition_or_member.extended_attributes
                for extended_attribute in extended_attribute_list)
 
 
 def has_extended_attribute_value(definition_or_member, name, value):
     extended_attributes = definition_or_member.extended_attributes
     return (name in extended_attributes and
             extended_attribute_value_contains(extended_attributes[name], value))
 
 
+def sorted_extended_attribute_set(definition_or_member, name):
+    extended_attributes = definition_or_member.extended_attributes
+    if name not in extended_attributes:
+        return set()
+
+    attribute_values = re.split('[|&]', extended_attributes[name])
+    return set(sorted(attribute_values))

[Jens Widell, 2014/07/30 15:16:18]

This doesn't work. It's the construction of the set that randomizes the order
(since sets are unordered), so it's at the point where you enumerate the items
in the set that you need to sort.

(Note that CPython, without the -R command line switch, probably has stable
order in practice, and thus that this doesn't lead to *varying* random order,
but it's bad practice to rely on this.)

+
+
 ################################################################################
 # String handling
 ################################################################################
 
 def capitalize(name):
     """Capitalize first letter or initial acronym (used in setter names)."""
     for acronym in ACRONYMS:
         if name.startswith(acronym.lower()):
             return name.replace(acronym.lower(), acronym)
     return name[0].upper() + name[1:]
@@ skipping 131 matching lines @@
 
 # [DeprecateAs]
 def deprecate_as(member):
     extended_attributes = member.extended_attributes
     if 'DeprecateAs' not in extended_attributes:
         return None
     includes.add('core/frame/UseCounter.h')
     return extended_attributes['DeprecateAs']
 
 
+# [Exposed]
+EXPOSED_EXECUTION_CONTEXT_METHOD = {
+    'DedicatedWorker': 'isDedicatedWorkerGlobalScope',
+    'ServiceWorker': 'isServiceWorkerGlobalScope',
+    'SharedWorker': 'isSharedWorkerGlobalScope',
+    'Window': 'isDocument',
+    'Worker': 'isWorkerGlobalScope',
+}
+
+def exposed(definition_or_member, interface):
+    extended_attributes = definition_or_member.extended_attributes
+    if 'Exposed' not in extended_attributes:
+        return None
+
+    exposure_set = sorted_extended_attribute_set(definition_or_member, 'Exposed')
+    interface_exposure_set = expanded_exposure_set_for_interface(interface)
+
+    # Methods must not be exposed to a broader scope than their interface.
+    if not exposure_set.issubset(interface_exposure_set):
+        raise Exception('Interface members\' exposure sets must be a subset of the interface\'s.')
+
+    exposure_checks = []
+    for environment in exposure_set:
+        # Methods must be exposed on one of the scopes known to Blink.
+        if environment not in EXPOSED_EXECUTION_CONTEXT_METHOD:
+            raise Exception('Values for the [Exposed] annotation must reflect to a valid exposure scope.')
+
+        exposure_checks.append('context->%s()' % EXPOSED_EXECUTION_CONTEXT_METHOD[environment])
+
+    return ' || '.join(exposure_checks)
+
+
+def expanded_exposure_set_for_interface(interface):
+    exposure_set = sorted_extended_attribute_set(interface, 'Exposed')
+
+    # "Worker" is an aggregation for the different kinds of workers.
+    if 'Worker' in exposure_set:
+        exposure_set.update(('DedicatedWorker', 'SharedWorker', 'ServiceWorker'))
+
+    return set(sorted(exposure_set))
+
+
 # [GarbageCollected], [WillBeGarbageCollected]
 def gc_type(definition):
     extended_attributes = definition.extended_attributes
     if 'GarbageCollected' in extended_attributes:
         return 'GarbageCollectedObject'
     elif 'WillBeGarbageCollected' in extended_attributes:
         return 'WillBeGarbageCollectedObject'
     return 'RefCountedObject'
 
 
@@ skipping 29 matching lines @@
 
     The returned function checks if a method/attribute is enabled.
     Given extended attribute RuntimeEnabled=FeatureName, return:
         RuntimeEnabledFeatures::{featureName}Enabled
     """
     extended_attributes = definition_or_member.extended_attributes
     if 'RuntimeEnabled' not in extended_attributes:
         return None
     feature_name = extended_attributes['RuntimeEnabled']
     return 'RuntimeEnabledFeatures::%sEnabled' % uncapitalize(feature_name)