path: root/Source/bindings/scripts/v8_attributes.py

# Copyright (C) 2013 Google Inc. All rights reserved.
#
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# modification, are permitted provided that the following conditions are
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#
#     * Redistributions of source code must retain the above copyright
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"""Generate template values for attributes.

Extends IdlType with property |constructor_type_name|.

Design doc: http://www.chromium.org/developers/design-documents/idl-compiler
"""

import idl_types
from idl_types import inherits_interface
from v8_globals import includes, interfaces
import v8_types
import v8_utilities
from v8_utilities import capitalize, cpp_name, has_extended_attribute, has_extended_attribute_value, scoped_name, strip_suffix, uncapitalize


def generate_attribute(interface, attribute):
    idl_type = attribute.idl_type
    base_idl_type = idl_type.base_type
    extended_attributes = attribute.extended_attributes

    idl_type.add_includes_for_type()

    # [CheckSecurity]
    is_check_security_for_node = 'CheckSecurity' in extended_attributes
    if is_check_security_for_node:
        includes.add('bindings/v8/BindingSecurity.h')
    # [Custom]
    has_custom_getter = ('Custom' in extended_attributes and
                         extended_attributes['Custom'] in [None, 'Getter'])
    has_custom_setter = (not attribute.is_read_only and
                         'Custom' in extended_attributes and
                         extended_attributes['Custom'] in [None, 'Setter'])
    # [CustomElementCallbacks], [Reflect]
    is_custom_element_callbacks = 'CustomElementCallbacks' in extended_attributes
    is_reflect = 'Reflect' in extended_attributes
    if is_custom_element_callbacks or is_reflect:
        includes.add('core/dom/custom/CustomElementCallbackDispatcher.h')
    # [PerWorldBindings]
    if 'PerWorldBindings' in extended_attributes:
        assert idl_type.is_wrapper_type or 'LogActivity' in extended_attributes, '[PerWorldBindings] should only be used with wrapper types: %s.%s' % (interface.name, attribute.name)
    # [RaisesException], [RaisesException=Setter]
    is_setter_raises_exception = (
        'RaisesException' in extended_attributes and
        extended_attributes['RaisesException'] in [None, 'Setter'])
    # [TypeChecking]
    has_type_checking_interface = (
        (has_extended_attribute_value(interface, 'TypeChecking', 'Interface') or
         has_extended_attribute_value(attribute, 'TypeChecking', 'Interface')) and
        idl_type.is_wrapper_type)
    has_type_checking_nullable = (
        (has_extended_attribute_value(interface, 'TypeChecking', 'Nullable') or
         has_extended_attribute_value(attribute, 'TypeChecking', 'Nullable')) and
         idl_type.is_wrapper_type)
    has_type_checking_unrestricted = (
        (has_extended_attribute_value(interface, 'TypeChecking', 'Unrestricted') or
         has_extended_attribute_value(attribute, 'TypeChecking', 'Unrestricted')) and
         idl_type.name in ('Float', 'Double'))

    if (base_idl_type == 'EventHandler' and
        interface.name in ['Window', 'WorkerGlobalScope'] and
        attribute.name == 'onerror'):
        includes.add('bindings/v8/V8ErrorHandler.h')

    contents = {
        'access_control_list': access_control_list(attribute),
        'activity_logging_world_list_for_getter': v8_utilities.activity_logging_world_list(attribute, 'Getter'),  # [ActivityLogging]
        'activity_logging_world_list_for_setter': v8_utilities.activity_logging_world_list(attribute, 'Setter'),  # [ActivityLogging]
        'activity_logging_include_old_value_for_setter': 'LogPreviousValue' in extended_attributes,  # [ActivityLogging]
        'activity_logging_world_check': v8_utilities.activity_logging_world_check(attribute),  # [ActivityLogging]
        'cached_attribute_validation_method': extended_attributes.get('CachedAttribute'),
        'conditional_string': v8_utilities.conditional_string(attribute),
        'constructor_type': idl_type.constructor_type_name
                            if is_constructor_attribute(attribute) else None,
        'cpp_name': cpp_name(attribute),
        'cpp_type': idl_type.cpp_type,
        'cpp_value_to_v8_value': idl_type.cpp_value_to_v8_value(cpp_value='original', creation_context='info.Holder()'),
        'deprecate_as': v8_utilities.deprecate_as(attribute),  # [DeprecateAs]
        'enum_validation_expression': idl_type.enum_validation_expression,
        'has_custom_getter': has_custom_getter,
        'has_custom_setter': has_custom_setter,
        'has_setter_exception_state':
            is_setter_raises_exception or has_type_checking_interface or
            has_type_checking_nullable or has_type_checking_unrestricted or
            idl_type.may_raise_exception_on_conversion,
        'has_type_checking_interface': has_type_checking_interface,
        'has_type_checking_nullable': has_type_checking_nullable,
        'has_type_checking_unrestricted': has_type_checking_unrestricted,
        'idl_type': str(idl_type),  # need trailing [] on array for Dictionary::ConversionContext::setConversionType
        'is_call_with_execution_context': v8_utilities.has_extended_attribute_value(attribute, 'CallWith', 'ExecutionContext'),
        'is_call_with_script_state': v8_utilities.has_extended_attribute_value(attribute, 'CallWith', 'ScriptState'),
        'is_check_security_for_node': is_check_security_for_node,
        'is_custom_element_callbacks': is_custom_element_callbacks,
        'is_expose_js_accessors': 'ExposeJSAccessors' in extended_attributes,
        'is_getter_raises_exception':  # [RaisesException]
            'RaisesException' in extended_attributes and
            extended_attributes['RaisesException'] in (None, 'Getter'),
        'is_initialized_by_event_constructor':
            'InitializedByEventConstructor' in extended_attributes,
        'is_keep_alive_for_gc': is_keep_alive_for_gc(interface, attribute),
        'is_nullable': attribute.idl_type.is_nullable,
        'is_partial_interface_member':
            'PartialInterfaceImplementedAs' in extended_attributes,
        'is_per_world_bindings': 'PerWorldBindings' in extended_attributes,
        'is_read_only': attribute.is_read_only,
        'is_reflect': is_reflect,
        'is_replaceable': 'Replaceable' in attribute.extended_attributes,
        'is_setter_call_with_execution_context': v8_utilities.has_extended_attribute_value(attribute, 'SetterCallWith', 'ExecutionContext'),
        'is_setter_raises_exception': is_setter_raises_exception,
        'is_static': attribute.is_static,
        'is_url': 'URL' in extended_attributes,
        'is_unforgeable': 'Unforgeable' in extended_attributes,
        'measure_as': v8_utilities.measure_as(attribute),  # [MeasureAs]
        'name': attribute.name,
        'per_context_enabled_function': v8_utilities.per_context_enabled_function_name(attribute),  # [PerContextEnabled]
        'property_attributes': property_attributes(attribute),
        'put_forwards': 'PutForwards' in extended_attributes,
        'reflect_empty': extended_attributes.get('ReflectEmpty'),
        'reflect_invalid': extended_attributes.get('ReflectInvalid', ''),
        'reflect_missing': extended_attributes.get('ReflectMissing'),
        'reflect_only': extended_attributes['ReflectOnly'].split('|')
            if 'ReflectOnly' in extended_attributes else None,
        'setter_callback': setter_callback_name(interface, attribute),
        'v8_type': v8_types.v8_type(base_idl_type),
        'runtime_enabled_function': v8_utilities.runtime_enabled_function_name(attribute),  # [RuntimeEnabled]
        'world_suffixes': ['', 'ForMainWorld']
                          if 'PerWorldBindings' in extended_attributes
                          else [''],  # [PerWorldBindings]
    }

    if is_constructor_attribute(attribute):
        generate_constructor_getter(interface, attribute, contents)
        return contents
    if not has_custom_getter:
        generate_getter(interface, attribute, contents)
    if (not has_custom_setter and
        (not attribute.is_read_only or 'PutForwards' in extended_attributes)):
        generate_setter(interface, attribute, contents)

    return contents


################################################################################
# Getter
################################################################################

def generate_getter(interface, attribute, contents):
    idl_type = attribute.idl_type
    base_idl_type = idl_type.base_type
    extended_attributes = attribute.extended_attributes

    cpp_value = getter_expression(interface, attribute, contents)
    # Normally we can inline the function call into the return statement to
    # avoid the overhead of using a Ref<> temporary, but for some cases
    # (nullable types, EventHandler, [CachedAttribute], or if there are
    # exceptions), we need to use a local variable.
    # FIXME: check if compilers are smart enough to inline this, and if so,
    # always use a local variable (for readability and CG simplicity).
    release = False
    if (idl_type.is_nullable or
        base_idl_type == 'EventHandler' or
        'CachedAttribute' in extended_attributes or
        'ReflectOnly' in extended_attributes or
        contents['is_getter_raises_exception']):
        contents['cpp_value_original'] = cpp_value
        cpp_value = 'v8Value'
        # EventHandler has special handling
        if base_idl_type != 'EventHandler' and idl_type.is_interface_type:
            release = True

    def v8_set_return_value_statement(for_main_world=False):
        if contents['is_keep_alive_for_gc']:
            return 'v8SetReturnValue(info, wrapper)'
        return idl_type.v8_set_return_value(cpp_value, extended_attributes=extended_attributes, script_wrappable='impl', release=release, for_main_world=for_main_world)

    contents.update({
        'cpp_value': cpp_value,
        'cpp_value_to_v8_value': idl_type.cpp_value_to_v8_value(cpp_value=cpp_value, creation_context='info.Holder()'),
        'v8_set_return_value_for_main_world': v8_set_return_value_statement(for_main_world=True),
        'v8_set_return_value': v8_set_return_value_statement(),
    })


def getter_expression(interface, attribute, contents):
    arguments = []
    this_getter_base_name = getter_base_name(interface, attribute, arguments)
    getter_name = scoped_name(interface, attribute, this_getter_base_name)

    arguments.extend(v8_utilities.call_with_arguments(
        attribute.extended_attributes.get('CallWith')))
    # Members of IDL partial interface definitions are implemented in C++ as
    # static member functions, which for instance members (non-static members)
    # take *impl as their first argument
    if ('PartialInterfaceImplementedAs' in attribute.extended_attributes and
        not attribute.is_static):
        arguments.append('*impl')
    if attribute.idl_type.is_nullable and not contents['has_type_checking_nullable']:
        arguments.append('isNull')
    if contents['is_getter_raises_exception']:
        arguments.append('exceptionState')
    return '%s(%s)' % (getter_name, ', '.join(arguments))


CONTENT_ATTRIBUTE_GETTER_NAMES = {
    'boolean': 'fastHasAttribute',
    'long': 'getIntegralAttribute',
    'unsigned long': 'getUnsignedIntegralAttribute',
}


def getter_base_name(interface, attribute, arguments):
    extended_attributes = attribute.extended_attributes
    if 'Reflect' not in extended_attributes:
        return uncapitalize(cpp_name(attribute))

    content_attribute_name = extended_attributes['Reflect'] or attribute.name.lower()
    if content_attribute_name in ['class', 'id', 'name']:
        # Special-case for performance optimization.
        return 'get%sAttribute' % content_attribute_name.capitalize()

    arguments.append(scoped_content_attribute_name(interface, attribute))

    base_idl_type = attribute.idl_type.base_type
    if base_idl_type in CONTENT_ATTRIBUTE_GETTER_NAMES:
        return CONTENT_ATTRIBUTE_GETTER_NAMES[base_idl_type]
    if 'URL' in attribute.extended_attributes:
        return 'getURLAttribute'
    return 'fastGetAttribute'


def is_keep_alive_for_gc(interface, attribute):
    idl_type = attribute.idl_type
    base_idl_type = idl_type.base_type
    extended_attributes = attribute.extended_attributes
    return (
        # For readonly attributes, for performance reasons we keep the attribute
        # wrapper alive while the owner wrapper is alive, because the attribute
        # never changes.
        (attribute.is_read_only and
         idl_type.is_wrapper_type and
         # There are some exceptions, however:
         not(
             # Node lifetime is managed by object grouping.
             inherits_interface(interface.name, 'Node') or
             inherits_interface(base_idl_type, 'Node') or
             # A self-reference is unnecessary.
             attribute.name == 'self' or
             # FIXME: Remove these hard-coded hacks.
             base_idl_type in ['EventTarget', 'Window'] or
             base_idl_type.startswith(('HTML', 'SVG')))))


################################################################################
# Setter
################################################################################

def generate_setter(interface, attribute, contents):
    def target_attribute():
        target_interface_name = attribute.idl_type.base_type
        target_attribute_name = extended_attributes['PutForwards']
        target_interface = interfaces[target_interface_name]
        try:
            return next(attribute
                        for attribute in target_interface.attributes
                        if attribute.name == target_attribute_name)
        except StopIteration:
            raise Exception('[PutForward] target not found:\n'
                            'Attribute "%s" is not present in interface "%s"' %
                            (target_attribute_name, target_interface_name))

    extended_attributes = attribute.extended_attributes

    if 'PutForwards' in extended_attributes:
        # Use target attribute in place of original attribute
        attribute = target_attribute()

    contents.update({
        'cpp_setter': setter_expression(interface, attribute, contents),
        'v8_value_to_local_cpp_value': attribute.idl_type.v8_value_to_local_cpp_value(extended_attributes, 'v8Value', 'cppValue'),
    })


def setter_expression(interface, attribute, contents):
    extended_attributes = attribute.extended_attributes
    arguments = v8_utilities.call_with_arguments(
        extended_attributes.get('SetterCallWith') or
        extended_attributes.get('CallWith'))

    this_setter_base_name = setter_base_name(interface, attribute, arguments)
    setter_name = scoped_name(interface, attribute, this_setter_base_name)

    # Members of IDL partial interface definitions are implemented in C++ as
    # static member functions, which for instance members (non-static members)
    # take *impl as their first argument
    if ('PartialInterfaceImplementedAs' in extended_attributes and
        not attribute.is_static):
        arguments.append('*impl')
    idl_type = attribute.idl_type
    if idl_type.base_type == 'EventHandler':
        getter_name = scoped_name(interface, attribute, cpp_name(attribute))
        contents['event_handler_getter_expression'] = '%s(%s)' % (
            getter_name, ', '.join(arguments))
        if (interface.name in ['Window', 'WorkerGlobalScope'] and
            attribute.name == 'onerror'):
            includes.add('bindings/v8/V8ErrorHandler.h')
            arguments.append('V8EventListenerList::findOrCreateWrapper<V8ErrorHandler>(v8Value, true, ScriptState::current(info.GetIsolate()))')
        else:
            arguments.append('V8EventListenerList::getEventListener(ScriptState::current(info.GetIsolate()), v8Value, true, ListenerFindOrCreate)')
    elif idl_type.is_interface_type and not idl_type.array_type:
        # FIXME: should be able to eliminate WTF::getPtr in most or all cases
        arguments.append('WTF::getPtr(cppValue)')
    else:
        arguments.append('cppValue')
    if contents['is_setter_raises_exception']:
        arguments.append('exceptionState')

    return '%s(%s)' % (setter_name, ', '.join(arguments))


CONTENT_ATTRIBUTE_SETTER_NAMES = {
    'boolean': 'setBooleanAttribute',
    'long': 'setIntegralAttribute',
    'unsigned long': 'setUnsignedIntegralAttribute',
}


def setter_base_name(interface, attribute, arguments):
    if 'Reflect' not in attribute.extended_attributes:
        return 'set%s' % capitalize(cpp_name(attribute))
    arguments.append(scoped_content_attribute_name(interface, attribute))

    base_idl_type = attribute.idl_type.base_type
    if base_idl_type in CONTENT_ATTRIBUTE_SETTER_NAMES:
        return CONTENT_ATTRIBUTE_SETTER_NAMES[base_idl_type]
    return 'setAttribute'


def scoped_content_attribute_name(interface, attribute):
    content_attribute_name = attribute.extended_attributes['Reflect'] or attribute.name.lower()
    namespace = 'SVGNames' if interface.name.startswith('SVG') else 'HTMLNames'
    includes.add('core/%s.h' % namespace)
    return '%s::%sAttr' % (namespace, content_attribute_name)


################################################################################
# Attribute configuration
################################################################################

# [Replaceable]
def setter_callback_name(interface, attribute):
    cpp_class_name = cpp_name(interface)
    extended_attributes = attribute.extended_attributes
    if (('Replaceable' in extended_attributes and
         'PutForwards' not in extended_attributes) or
        is_constructor_attribute(attribute)):
        return '{0}V8Internal::{0}ForceSetAttributeOnThisCallback'.format(cpp_class_name)
    if attribute.is_read_only and 'PutForwards' not in extended_attributes:
        return '0'
    return '%sV8Internal::%sAttributeSetterCallback' % (cpp_class_name, attribute.name)


# [DoNotCheckSecurity], [Unforgeable]
def access_control_list(attribute):
    extended_attributes = attribute.extended_attributes
    access_control = []
    if 'DoNotCheckSecurity' in extended_attributes:
        do_not_check_security = extended_attributes['DoNotCheckSecurity']
        if do_not_check_security == 'Setter':
            access_control.append('v8::ALL_CAN_WRITE')
        else:
            access_control.append('v8::ALL_CAN_READ')
            if (not attribute.is_read_only or
                'Replaceable' in extended_attributes):
                access_control.append('v8::ALL_CAN_WRITE')
    if 'Unforgeable' in extended_attributes:
        access_control.append('v8::PROHIBITS_OVERWRITING')
    return access_control or ['v8::DEFAULT']


# [NotEnumerable], [Unforgeable]
def property_attributes(attribute):
    extended_attributes = attribute.extended_attributes
    property_attributes_list = []
    if ('NotEnumerable' in extended_attributes or
        is_constructor_attribute(attribute)):
        property_attributes_list.append('v8::DontEnum')
    if 'Unforgeable' in extended_attributes:
        property_attributes_list.append('v8::DontDelete')
    return property_attributes_list or ['v8::None']


################################################################################
# Constructors
################################################################################

idl_types.IdlType.constructor_type_name = property(
    # FIXME: replace this with a [ConstructorAttribute] extended attribute
    lambda self: strip_suffix(self.base_type, 'Constructor'))


def is_constructor_attribute(attribute):
    # FIXME: replace this with [ConstructorAttribute] extended attribute
    return attribute.idl_type.base_type.endswith('Constructor')


def generate_constructor_getter(interface, attribute, contents):
    contents['needs_constructor_getter_callback'] = contents['measure_as'] or contents['deprecate_as']