[Bindings] Make maplike<> and setlike<> imply a readonly size attribute.

third_party/WebKit/Source/bindings/scripts/v8_interface.py

 # Copyright (C) 2013 Google Inc. All rights reserved.
 # coding=utf-8
 #
 # 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 17 matching lines @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 # pylint: disable=relative-import
 
 """Generate template values for an interface.
 
 Design doc: http://www.chromium.org/developers/design-documents/idl-compiler
 """
 from operator import or_
 
-from idl_definitions import IdlOperation, IdlArgument
+from idl_definitions import IdlAttribute, IdlOperation, IdlArgument
 from idl_types import IdlType, inherits_interface
 from overload_set_algorithm import effective_overload_set_by_length
 from overload_set_algorithm import method_overloads_by_name
 
 import v8_attributes
 from v8_globals import includes
 import v8_methods
 import v8_types
 import v8_utilities
 from v8_utilities import (cpp_name_or_partial, cpp_name, has_extended_attribute_value,
@@ skipping 294 matching lines @@
         'unscopables': sorted(unscopables),
     })
 
     # Constants
     context.update({
         'constants': [constant_context(constant, interface) for constant in interface.constants],
         'do_not_check_constants': 'DoNotCheckConstants' in extended_attributes,
     })
 
     # Attributes
-    attributes = [v8_attributes.attribute_context(interface, attribute, interfaces)
-                  for attribute in interface.attributes]
-
-    has_conditional_attributes = any(attribute['exposed_test'] for attribute in attributes)
-    if has_conditional_attributes and interface.is_partial:
-        raise Exception('Conditional attributes between partial interfaces in modules and the original interfaces(%s) in core are not allowed.' % interface.name)
-
+    attributes = attributes_context(interface, interfaces)
     context.update({
         'attributes': attributes,
         # Elements in attributes are broken in following members.
         'accessors': v8_attributes.filter_accessors(attributes),
         'data_attributes': v8_attributes.filter_data_attributes(attributes),
         'lazy_data_attributes': v8_attributes.filter_lazy_data_attributes(attributes),
         'origin_trial_attributes': v8_attributes.filter_origin_trial_enabled(attributes),
         'runtime_enabled_attributes': v8_attributes.filter_runtime_enabled(attributes),
     })
 
@@ skipping 85 matching lines @@
     context.update({
         'has_cross_origin_named_getter': has_cross_origin_named_getter,
         'has_cross_origin_named_setter': has_cross_origin_named_setter,
         'has_cross_origin_named_enumerator': has_cross_origin_named_enumerator,
         'has_cross_origin_indexed_getter': has_cross_origin_indexed_getter,
     })
 
     return context
 
 
+def attributes_context(interface, interfaces):
+    """Creates a list of Jinja template contexts for attributes of an interface.
+
+    Args:
+        interface: An interface to create contexts for
+        interfaces: A dict which maps an interface name to the definition
+            which can be referred if needed
+
+    Returns:
+        A list of attribute contexts
+    """
+
+    attributes = [v8_attributes.attribute_context(interface, attribute, interfaces)
+                  for attribute in interface.attributes]
+
+    has_conditional_attributes = any(attribute['exposed_test'] for attribute in attributes)
+    if has_conditional_attributes and interface.is_partial:
+        raise Exception(
+            'Conditional attributes between partial interfaces in modules '
+            'and the original interfaces(%s) in core are not allowed.'
+            % interface.name)
+
+    # See also comment in methods_context.
+    if not interface.is_partial and (interface.maplike or interface.setlike):
+        if any(attribute['name'] == 'size' for attribute in attributes):
+            raise ValueError(
+                'An interface cannot define an attribute called "size"; it is '
+                'implied by maplike/setlike in the IDL.')
+        size_attribute = IdlAttribute()
+        size_attribute.name = 'size'
+        size_attribute.idl_type = IdlType('unsigned long')
+        size_attribute.is_read_only = True
+        size_attribute.extended_attributes['NotEnumerable'] = None
+        attributes.append(v8_attributes.attribute_context(
+            interface, size_attribute, interfaces))
+
+    return attributes
+
+
 def methods_context(interface):
     """Creates a list of Jinja template contexts for methods of an interface.
 
     Args:
         interface: An interface to create contexts for
 
     Returns:
         A list of method contexts, and an iterator context if available or None
     """
 
@@ skipping 901 matching lines @@
     extended_attributes = deleter.extended_attributes
     is_call_with_script_state = v8_utilities.has_extended_attribute_value(deleter, 'CallWith', 'ScriptState')
     is_ce_reactions = 'CEReactions' in extended_attributes
     return {
         'is_call_with_script_state': is_call_with_script_state,
         'is_ce_reactions': is_ce_reactions,
         'is_custom': 'Custom' in extended_attributes,
         'is_raises_exception': 'RaisesException' in extended_attributes,
         'name': cpp_name(deleter),
     }