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

Source/bindings/scripts/v8_utilities.py

Index: Source/bindings/scripts/v8_utilities.py
diff --git a/Source/bindings/scripts/v8_utilities.py b/Source/bindings/scripts/v8_utilities.py
index 674a1b8d9969b08a53404147c1c7e289db1f73f4..39acb1a0fdc36653ff9907d7c389081d5669212f 100644
--- a/Source/bindings/scripts/v8_utilities.py
+++ b/Source/bindings/scripts/v8_utilities.py
@@ -74,6 +74,15 @@ def has_extended_attribute_value(definition_or_member, name, value):
             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
 ################################################################################
@@ -225,6 +234,48 @@ def deprecate_as(member):
     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