path: root/third_party/WebKit/Source/bindings/scripts/v8_methods.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
# in the documentation and/or other materials provided with the
# distribution.
#     * Neither the name of Google Inc. nor the names of its
# contributors may be used to endorse or promote products derived from
# this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

"""Generate template values for methods.

Extends IdlArgument with property |default_cpp_value|.
Extends IdlTypeBase and IdlUnionType with property |union_arguments|.

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

from idl_definitions import IdlArgument
from idl_types import IdlTypeBase, IdlUnionType, inherits_interface
from v8_globals import includes
import v8_types
import v8_utilities
from v8_utilities import has_extended_attribute_value


# Methods with any of these require custom method registration code in the
# interface's configure*Template() function.
CUSTOM_REGISTRATION_EXTENDED_ATTRIBUTES = frozenset([
    'DoNotCheckSecurity',
    'DoNotCheckSignature',
    'NotEnumerable',
    'Unforgeable',
])


def argument_needs_try_catch(method, argument):
    return_promise = method.idl_type and method.idl_type.name == 'Promise'
    idl_type = argument.idl_type
    base_type = idl_type.base_type

    return not(
        # These cases are handled by separate code paths in the
        # generate_argument() macro in Source/bindings/templates/methods.cpp.
        idl_type.is_callback_interface or
        base_type == 'SerializedScriptValue' or
        (argument.is_variadic and idl_type.is_wrapper_type) or
        # Variadic arguments use toImplArguments() with throws excentions via
        # its ExceptionState& argument.
        argument.is_variadic or
        # String and enumeration arguments converted using one of the
        # TOSTRING_* macros except for _PROMISE variants in
        # Source/bindings/core/v8/V8BindingMacros.h don't use a v8::TryCatch.
        ((base_type == 'DOMString' or idl_type.is_enum) and
         not return_promise) or
        # Conversion that take an ExceptionState& argument throw all their
        # exceptions via it, and doesn't need/use a TryCatch, except if the
        # argument has [Clamp], in which case it uses a separate code path in
        # Source/bindings/templates/methods.cpp, which *does* use a TryCatch.
        argument.v8_conversion_needs_exception_state or
        # A trivial conversion cannot throw exceptions at all, so doesn't need a
        # TryCatch to catch them.
        idl_type.v8_conversion_is_trivial)


def use_local_result(method):
    extended_attributes = method.extended_attributes
    idl_type = method.idl_type
    return (has_extended_attribute_value(method, 'CallWith', 'ScriptState') or
            'ImplementedInPrivateScript' in extended_attributes or
            'RaisesException' in extended_attributes or
            idl_type.is_union_type or
            idl_type.is_explicit_nullable)


def method_context(interface, method):
    arguments = method.arguments
    extended_attributes = method.extended_attributes
    idl_type = method.idl_type
    is_static = method.is_static
    name = method.name

    idl_type.add_includes_for_type()
    this_cpp_value = cpp_value(interface, method, len(arguments))

    def function_template():
        if is_static:
            return 'functionTemplate'
        if 'Unforgeable' in extended_attributes:
            return 'instanceTemplate'
        return 'prototypeTemplate'

    is_implemented_in_private_script = 'ImplementedInPrivateScript' in extended_attributes
    if is_implemented_in_private_script:
        includes.add('bindings/core/v8/PrivateScriptRunner.h')
        includes.add('core/frame/LocalFrame.h')
        includes.add('platform/ScriptForbiddenScope.h')

    # [OnlyExposedToPrivateScript]
    is_only_exposed_to_private_script = 'OnlyExposedToPrivateScript' in extended_attributes

    is_call_with_script_arguments = has_extended_attribute_value(method, 'CallWith', 'ScriptArguments')
    if is_call_with_script_arguments:
        includes.update(['bindings/core/v8/ScriptCallStackFactory.h',
                         'core/inspector/ScriptArguments.h'])
    is_call_with_script_state = has_extended_attribute_value(method, 'CallWith', 'ScriptState')
    if is_call_with_script_state:
        includes.add('bindings/core/v8/ScriptState.h')
    is_check_security_for_node = 'CheckSecurity' in extended_attributes
    if is_check_security_for_node:
        includes.add('bindings/core/v8/BindingSecurity.h')
    is_custom_element_callbacks = 'CustomElementCallbacks' in extended_attributes
    if is_custom_element_callbacks:
        includes.add('core/dom/custom/CustomElementProcessingStack.h')

    is_do_not_check_security = 'DoNotCheckSecurity' in extended_attributes

    is_check_security_for_frame = (
        has_extended_attribute_value(interface, 'CheckSecurity', 'Frame') and
        not is_do_not_check_security)

    is_check_security_for_window = (
        has_extended_attribute_value(interface, 'CheckSecurity', 'Window') and
        not is_do_not_check_security)

    is_raises_exception = 'RaisesException' in extended_attributes

    arguments_need_try_catch = (
        any(argument_needs_try_catch(method, argument)
            for argument in arguments))

    return {
        'activity_logging_world_list': v8_utilities.activity_logging_world_list(method),  # [ActivityLogging]
        'arguments': [argument_context(interface, method, argument, index)
                      for index, argument in enumerate(arguments)],
        'argument_declarations_for_private_script':
            argument_declarations_for_private_script(interface, method),
        'arguments_need_try_catch': arguments_need_try_catch,
        'conditional_string': v8_utilities.conditional_string(method),
        'cpp_type': (v8_types.cpp_template_type('Nullable', idl_type.cpp_type)
                     if idl_type.is_explicit_nullable else idl_type.cpp_type),
        'cpp_value': this_cpp_value,
        'cpp_type_initializer': idl_type.cpp_type_initializer,
        'custom_registration_extended_attributes':
            CUSTOM_REGISTRATION_EXTENDED_ATTRIBUTES.intersection(
                extended_attributes.iterkeys()),
        'deprecate_as': v8_utilities.deprecate_as(method),  # [DeprecateAs]
        'exposed_test': v8_utilities.exposed(method, interface),  # [Exposed]
        'function_template': function_template(),
        'has_custom_registration': is_static or
            v8_utilities.has_extended_attribute(
                method, CUSTOM_REGISTRATION_EXTENDED_ATTRIBUTES),
        'has_exception_state':
            is_raises_exception or
            is_check_security_for_frame or
            is_check_security_for_window or
            any(argument for argument in arguments
                if (argument.idl_type.name == 'SerializedScriptValue' or
                    argument.v8_conversion_needs_exception_state)),
        'idl_type': idl_type.base_type,
        'is_call_with_execution_context': has_extended_attribute_value(method, 'CallWith', 'ExecutionContext'),
        'is_call_with_script_arguments': is_call_with_script_arguments,
        'is_call_with_script_state': is_call_with_script_state,
        'is_check_security_for_frame': is_check_security_for_frame,
        'is_check_security_for_node': is_check_security_for_node,
        'is_check_security_for_window': is_check_security_for_window,
        'is_custom': 'Custom' in extended_attributes,
        'is_custom_element_callbacks': is_custom_element_callbacks,
        'is_do_not_check_security': is_do_not_check_security,
        'is_do_not_check_signature': 'DoNotCheckSignature' in extended_attributes,
        'is_explicit_nullable': idl_type.is_explicit_nullable,
        'is_implemented_in_private_script': is_implemented_in_private_script,
        'is_partial_interface_member':
            'PartialInterfaceImplementedAs' in extended_attributes,
        'is_per_world_bindings': 'PerWorldBindings' in extended_attributes,
        'is_raises_exception': is_raises_exception,
        'is_read_only': 'Unforgeable' in extended_attributes,
        'is_static': is_static,
        'is_variadic': arguments and arguments[-1].is_variadic,
        'measure_as': v8_utilities.measure_as(method),  # [MeasureAs]
        'name': name,
        'number_of_arguments': len(arguments),
        'number_of_required_arguments': len([
            argument for argument in arguments
            if not (argument.is_optional or argument.is_variadic)]),
        'number_of_required_or_variadic_arguments': len([
            argument for argument in arguments
            if not argument.is_optional]),
        'only_exposed_to_private_script': is_only_exposed_to_private_script,
        'per_context_enabled_function': v8_utilities.per_context_enabled_function_name(method),  # [PerContextEnabled]
        'private_script_v8_value_to_local_cpp_value': idl_type.v8_value_to_local_cpp_value(
            extended_attributes, 'v8Value', 'cppValue', isolate='scriptState->isolate()', used_in_private_script=True),
        'property_attributes': property_attributes(method),
        'runtime_enabled_function': v8_utilities.runtime_enabled_function_name(method),  # [RuntimeEnabled]
        'should_be_exposed_to_script': not (is_implemented_in_private_script and is_only_exposed_to_private_script),
        'signature': 'v8::Local<v8::Signature>()' if is_static or 'DoNotCheckSignature' in extended_attributes else 'defaultSignature',
        'union_arguments': idl_type.union_arguments,
        'use_local_result': use_local_result(method),
        'v8_set_return_value': v8_set_return_value(interface.name, method, this_cpp_value),
        'v8_set_return_value_for_main_world': v8_set_return_value(interface.name, method, this_cpp_value, for_main_world=True),
        'world_suffixes': ['', 'ForMainWorld'] if 'PerWorldBindings' in extended_attributes else [''],  # [PerWorldBindings],
    }


def argument_context(interface, method, argument, index):
    extended_attributes = argument.extended_attributes
    idl_type = argument.idl_type
    this_cpp_value = cpp_value(interface, method, index)
    is_variadic_wrapper_type = argument.is_variadic and idl_type.is_wrapper_type
    return_promise = (method.idl_type.name == 'Promise' if method.idl_type
                                                        else False)

    if ('ImplementedInPrivateScript' in extended_attributes and
        not idl_type.is_wrapper_type and
        not idl_type.is_basic_type):
        raise Exception('Private scripts supports only primitive types and DOM wrappers.')

    default_cpp_value = argument.default_cpp_value
    return {
        'cpp_type': idl_type.cpp_type_args(extended_attributes=extended_attributes,
                                           raw_type=True,
                                           used_as_variadic_argument=argument.is_variadic),
        'cpp_value': this_cpp_value,
        # FIXME: check that the default value's type is compatible with the argument's
        'default_value': default_cpp_value,
        'enum_validation_expression': idl_type.enum_validation_expression,
        'handle': '%sHandle' % argument.name,
        # FIXME: remove once [Default] removed and just use argument.default_value
        'has_default': 'Default' in extended_attributes or default_cpp_value,
        'has_type_checking_interface':
            (has_extended_attribute_value(interface, 'TypeChecking', 'Interface') or
             has_extended_attribute_value(method, 'TypeChecking', 'Interface')) and
            idl_type.is_wrapper_type,
        'has_type_checking_unrestricted':
            (has_extended_attribute_value(interface, 'TypeChecking', 'Unrestricted') or
             has_extended_attribute_value(method, 'TypeChecking', 'Unrestricted')) and
            idl_type.name in ('Float', 'Double'),
        # Dictionary is special-cased, but arrays and sequences shouldn't be
        'idl_type': idl_type.base_type,
        'idl_type_object': idl_type,
        'index': index,
        'is_callback_interface': idl_type.is_callback_interface,
        # FIXME: Remove generic 'Dictionary' special-casing
        'is_dictionary': idl_type.is_dictionary or idl_type.base_type == 'Dictionary',
        'is_nullable': idl_type.is_nullable,
        'is_optional': argument.is_optional,
        'is_variadic_wrapper_type': is_variadic_wrapper_type,
        'is_wrapper_type': idl_type.is_wrapper_type,
        'name': argument.name,
        'private_script_cpp_value_to_v8_value': idl_type.cpp_value_to_v8_value(
            argument.name, isolate='scriptState->isolate()',
            creation_context='scriptState->context()->Global()'),
        'v8_set_return_value': v8_set_return_value(interface.name, method, this_cpp_value),
        'v8_set_return_value_for_main_world': v8_set_return_value(interface.name, method, this_cpp_value, for_main_world=True),
        'v8_value_to_local_cpp_value': v8_value_to_local_cpp_value(argument, index, return_promise=return_promise),
        'vector_type': v8_types.cpp_ptr_type('Vector', 'HeapVector', idl_type.gc_type),
    }


def argument_declarations_for_private_script(interface, method):
    argument_declarations = ['LocalFrame* frame']
    argument_declarations.append('%s* holderImpl' % interface.name)
    argument_declarations.extend(['%s %s' % (argument.idl_type.cpp_type_args(
        used_as_rvalue_type=True), argument.name) for argument in method.arguments])
    if method.idl_type.name != 'void':
        argument_declarations.append('%s* %s' % (method.idl_type.cpp_type, 'result'))
    return argument_declarations


################################################################################
# Value handling
################################################################################

def cpp_value(interface, method, number_of_arguments):
    def cpp_argument(argument):
        idl_type = argument.idl_type
        if idl_type.name == 'EventListener':
            return argument.name
        if idl_type.is_dictionary:
            return '*%s' % argument.name
        if (idl_type.name in ['NodeFilter', 'NodeFilterOrNull',
                              'XPathNSResolver', 'XPathNSResolverOrNull']):
            # FIXME: remove this special case
            return '%s.release()' % argument.name
        return argument.name

    # Truncate omitted optional arguments
    arguments = method.arguments[:number_of_arguments]
    cpp_arguments = []
    if 'ImplementedInPrivateScript' in method.extended_attributes:
        cpp_arguments.append('toFrameIfNotDetached(info.GetIsolate()->GetCurrentContext())')
        cpp_arguments.append('impl')

    if method.is_constructor:
        call_with_values = interface.extended_attributes.get('ConstructorCallWith')
    else:
        call_with_values = method.extended_attributes.get('CallWith')
    cpp_arguments.extend(v8_utilities.call_with_arguments(call_with_values))

    # 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 method.extended_attributes and
        not 'ImplementedInPrivateScript' in method.extended_attributes and
        not method.is_static):
        cpp_arguments.append('*impl')
    cpp_arguments.extend(cpp_argument(argument) for argument in arguments)

    this_union_arguments = method.idl_type and method.idl_type.union_arguments
    if this_union_arguments:
        cpp_arguments.extend([member_argument['cpp_value']
                              for member_argument in this_union_arguments])

    if 'ImplementedInPrivateScript' in method.extended_attributes:
        if method.idl_type.name != 'void':
            cpp_arguments.append('&result')
    elif ('RaisesException' in method.extended_attributes or
        (method.is_constructor and
         has_extended_attribute_value(interface, 'RaisesException', 'Constructor'))):
        cpp_arguments.append('exceptionState')

    if method.name == 'Constructor':
        base_name = 'create'
    elif method.name == 'NamedConstructor':
        base_name = 'createForJSConstructor'
    elif 'ImplementedInPrivateScript' in method.extended_attributes:
        base_name = '%sMethod' % method.name
    else:
        base_name = v8_utilities.cpp_name(method)

    cpp_method_name = v8_utilities.scoped_name(interface, method, base_name)
    return '%s(%s)' % (cpp_method_name, ', '.join(cpp_arguments))


def v8_set_return_value(interface_name, method, cpp_value, for_main_world=False):
    idl_type = method.idl_type
    extended_attributes = method.extended_attributes
    if not idl_type or idl_type.name == 'void':
        # Constructors and void methods don't have a return type
        return None

    if ('ImplementedInPrivateScript' in extended_attributes and
        not idl_type.is_wrapper_type and
        not idl_type.is_basic_type):
        raise Exception('Private scripts supports only primitive types and DOM wrappers.')

    release = False
    # [CallWith=ScriptState], [RaisesException]
    if use_local_result(method):
        if idl_type.is_explicit_nullable:
            # result is of type Nullable<T>
            cpp_value = 'result.get()'
        else:
            cpp_value = 'result'
        release = idl_type.release

    script_wrappable = 'impl' if inherits_interface(interface_name, 'Node') else ''
    return idl_type.v8_set_return_value(cpp_value, extended_attributes, script_wrappable=script_wrappable, release=release, for_main_world=for_main_world)


def v8_value_to_local_cpp_variadic_value(argument, index, return_promise):
    assert argument.is_variadic
    idl_type = argument.idl_type

    suffix = ''

    macro = 'TONATIVE_VOID_EXCEPTIONSTATE'
    macro_args = [
        argument.name,
        'toImplArguments<%s>(info, %s, exceptionState)' % (idl_type.cpp_type, index),
        'exceptionState',
    ]

    if return_promise:
        suffix += '_PROMISE'
        macro_args.extend(['info', 'ScriptState::current(info.GetIsolate())'])

    suffix += '_INTERNAL'

    return '%s%s(%s)' % (macro, suffix, ', '.join(macro_args))


def v8_value_to_local_cpp_value(argument, index, return_promise=False):
    extended_attributes = argument.extended_attributes
    idl_type = argument.idl_type
    name = argument.name
    if argument.is_variadic:
        return v8_value_to_local_cpp_variadic_value(argument, index, return_promise)
    return idl_type.v8_value_to_local_cpp_value(extended_attributes, 'info[%s]' % index,
                                                name, index=index, declare_variable=False, return_promise=return_promise)


################################################################################
# Auxiliary functions
################################################################################

# [NotEnumerable]
def property_attributes(method):
    extended_attributes = method.extended_attributes
    property_attributes_list = []
    if 'NotEnumerable' in extended_attributes:
        property_attributes_list.append('v8::DontEnum')
    if 'Unforgeable' in extended_attributes:
        property_attributes_list.append('v8::ReadOnly')
    if property_attributes_list:
        property_attributes_list.insert(0, 'v8::DontDelete')
    return property_attributes_list


def union_member_argument_context(idl_type, index):
    """Returns a context of union member for argument."""
    this_cpp_value = 'result%d' % index
    this_cpp_type = idl_type.cpp_type
    this_cpp_type_initializer = idl_type.cpp_type_initializer
    cpp_return_value = this_cpp_value

    if not idl_type.cpp_type_has_null_value:
        this_cpp_type = v8_types.cpp_template_type('Nullable', this_cpp_type)
        this_cpp_type_initializer = ''
        cpp_return_value = '%s.get()' % this_cpp_value

    if idl_type.is_string_type:
        null_check_value = '!%s.isNull()' % this_cpp_value
    else:
        null_check_value = this_cpp_value

    return {
        'cpp_type': this_cpp_type,
        'cpp_type_initializer': this_cpp_type_initializer,
        'cpp_value': this_cpp_value,
        'null_check_value': null_check_value,
        'v8_set_return_value': idl_type.v8_set_return_value(
            cpp_value=cpp_return_value,
            release=idl_type.release),
    }


def union_arguments(idl_type):
    return [union_member_argument_context(member_idl_type, index)
            for index, member_idl_type
            in enumerate(idl_type.member_types)]


def argument_default_cpp_value(argument):
    if argument.idl_type.is_dictionary:
        # We always create impl objects for IDL dictionaries.
        return '%s::create()' % argument.idl_type.base_type
    if not argument.default_value:
        return None
    return argument.idl_type.literal_cpp_value(argument.default_value)

IdlTypeBase.union_arguments = None
IdlUnionType.union_arguments = property(union_arguments)
IdlArgument.default_cpp_value = property(argument_default_cpp_value)


def v8_conversion_needs_exception_state(argument):
    return (argument.idl_type.v8_conversion_needs_exception_state or
            argument.is_variadic)

IdlArgument.v8_conversion_needs_exception_state = property(v8_conversion_needs_exception_state)