[Bindings] Create and use V8 context snapshots

third_party/WebKit/Source/bindings/scripts/generate_v8_context_snapshot_external_references.py

+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# pylint: disable=relative-import
+
+import argparse
+import os
+
+from code_generator import initialize_jinja_env
+from idl_reader import IdlReader
+from utilities import create_component_info_provider, write_file
+import utilities
+import v8_attributes
+import v8_interface
+import v8_types
+import v8_utilities
+
+
+INCLUDES = frozenset([
+    'bindings/core/v8/GeneratedCodeHelper.h',
+    'bindings/core/v8/V8HTMLDocument.h',
+    'bindings/core/v8/V8Initializer.h',
+    'bindings/core/v8/V8Window.h',
+    'platform/bindings/DOMWrapperWorld.h',
+    'platform/bindings/V8ObjectConstructor.h',
+    'platform/bindings/V8PerIsolateData.h',
+    'platform/bindings/V8PrivateProperty.h',
+    'v8/include/v8.h'])
+
+TEMPLATE_FILE = 'external_reference_table.cpp.tmpl'
+
+WHITE_LIST_INTERFACES = frozenset([
+    'DOMMatrix',  # crbug.com/733481
+])
+
+SNAPSHOTTED_INTERFACES = frozenset([
+    'Window',
+    'EventTarget',
+    'HTMLDocument',
+    'Document',
+    'Node',
+])
+
+
+def parse_args():
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--idl-files-list', type=str, required=True,
+                        help='file listing IDL files')
+    parser.add_argument('--output', type=str, required=True,
+                        help='output file path')
+    parser.add_argument('--info-dir', type=str, required=True,
+                        help='directory contains component info')
+    parser.add_argument('--cache-dir', type=str, required=True,
+                        help='cache directory')
+    parser.add_argument('--target-component', type=str, required=True,
+                        help='target component')
+    return parser.parse_known_args()
+
+
+# This class creates a Jinja template context about an interface.
+class InterfaceTemplateContextBuilder(object):
+
+    def __init__(self, opts, info_provider):
+        self._opts = opts
+        self._info_provider = info_provider
+
+    def create_interface_context(self, interface, interfaces):
+        '''Creates a Jinja context which is based on an interface.'''
+
+        name = '%s%s' % (v8_utilities.cpp_name(interface), 'Partial' if interface.is_partial else '')
+
+        # Constructors
+        constructors = any(constructor.name == 'Constructor' for constructor in interface.constructors)
+        custom_constructors = interface.custom_constructors
+        html_constructor = 'HTMLConstructor' in interface.extended_attributes
+        has_constructor_callback = constructors or custom_constructors or html_constructor
+
+        attributes = []
+        methods = []
+        is_global = False
+        named_property_getter = None
+        indexed_property_getter = None
+        has_origin_safe_method_setter = None
+        has_cross_origin_named_getter = None
+        if interface.name in SNAPSHOTTED_INTERFACES:
+            attributes = [v8_attributes.attribute_context(interface, attribute, interfaces)
+                          for attribute in interface.attributes]
+            methods = v8_interface.methods_context(interface)['methods']
+            is_global = ('PrimaryGlobal' in interface.extended_attributes or
+                         'Global' in interface.extended_attributes)
+
+            named_property_getter = v8_interface.property_getter(interface.named_property_getter, ['name'])
+            indexed_property_getter = v8_interface.property_getter(interface.indexed_property_getter, ['index'])
+
+            has_origin_safe_method_setter = not interface.is_partial and is_global and any(
+                method['is_check_security_for_receiver'] and not method['is_unforgeable']
+                for method in methods)
+            has_cross_origin_named_getter = (
+                any(attribute['has_cross_origin_getter'] for attribute in attributes) or
+                any(method['is_cross_origin'] for method in methods))
+
+        has_security_check = False
+        has_cross_origin_named_setter = False
+        has_cross_origin_named_enum = False
+        has_cross_origin_named_getter = False
+        has_cross_origin_indexed_getter = False
+        if not interface.is_partial:

[haraken, 2017/07/10 06:52:09]

Why doesn't the line 108 - 114 need to be in the 'if interface.name in
SNAPSHOTTED_INTERFACES:' block at line 86?

I guess the line 108 - 114 is needed only when the interface is in
SNAPSHOTTED_INTERFACES.

[peria, 2017/07/10 10:18:43]

Done.
This change reduce the number of the entries in the table. 2200->1400.
1400 is very close to the ideal number.

+            has_security_check = ('CheckSecurity' in interface.extended_attributes and
+                                  interface.name != 'EventTarget')
+            has_cross_origin_named_setter = any(attribute['has_cross_origin_setter'] for attribute in attributes)
+            has_cross_origin_named_enum = has_cross_origin_named_getter or has_cross_origin_named_setter
+            has_cross_origin_named_getter = named_property_getter and named_property_getter['is_cross_origin']
+            has_cross_origin_indexed_getter = indexed_property_getter and indexed_property_getter['is_cross_origin']
+
+        return {
+            'attributes': attributes,
+            'has_origin_safe_method_setter': has_origin_safe_method_setter,
+            'has_constructor_callback': has_constructor_callback,
+            '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_enum,
+            'has_cross_origin_indexed_getter': has_cross_origin_indexed_getter,
+            'has_security_check': has_security_check,
+            'indexed_property_getter': indexed_property_getter,
+            'indexed_property_setter': v8_interface.property_setter(interface.indexed_property_setter, interface),
+            'indexed_property_deleter': v8_interface.property_deleter(interface.indexed_property_deleter),
+            'is_array_buffer_or_view': interface.idl_type.is_array_buffer_or_view,
+            'is_callback': interface.is_callback,
+            'is_partial': interface.is_partial,
+            'is_snapshotted': interface in SNAPSHOTTED_INTERFACES,
+            'methods': methods,
+            'name': name,
+            'named_constructor': v8_interface.named_constructor_context(interface),
+            'named_property_getter': named_property_getter,
+            'named_property_setter': v8_interface.property_setter(interface.named_property_setter, interface),
+            'named_property_deleter': v8_interface.property_deleter(interface.named_property_deleter),
+            'v8_name': v8_utilities.v8_class_name_or_partial(interface),
+        }
+
+
+# This class applies a Jinja template and creates a .cpp file for the external reference table.
+class ExternalReferenceTableGenerator(object):
+    def __init__(self, opts, info_provider):
+        self._opts = opts
+        self._info_provider = info_provider
+        self._reader = IdlReader(
+            info_provider.interfaces_info, opts.cache_dir)
+        self._interface_contexts = {}
+        self._include_files = set(INCLUDES)
+        v8_types.set_component_dirs(info_provider.interfaces_info['component_dirs'])
+
+    def process_idl_file(self, idl_filename):
+        definitions = self._reader.read_idl_definitions(idl_filename)
+        base_name, _ = os.path.splitext(os.path.basename(idl_filename))
+        for component in definitions:
+            target_definitions = definitions[component]
+            interfaces = target_definitions.interfaces
+            if base_name in interfaces.keys():
+                interface = interfaces[base_name]
+                self._process_interface(interface, component, interfaces)
+
+    def _process_interface(self, interface, component, interfaces):
+        def has_impl(interface):

[haraken, 2017/07/10 06:52:09]

Add more comments about what this method is doing.

[peria, 2017/07/10 10:18:43]

Done.

+            if interface.name in WHITE_LIST_INTERFACES:
+                return True
+            # Non legacy callback interface does not provide V8 callbacks.
+            if interface.is_callback:
+                return len(interface.constants) > 0
+            if 'RuntimeEnabled' in interface.extended_attributes:
+                return False
+            return True
+
+        if not has_impl(interface):
+            return
+
+        context_builder = InterfaceTemplateContextBuilder(self._opts, self._info_provider)
+        context = context_builder.create_interface_context(interface, interfaces)
+        name = '%s%s' % (interface.name, 'Partial' if interface.is_partial else '')
+        self._interface_contexts[name] = context
+        include_file = 'bindings/%s/v8/%s.h' % (component, context['v8_name'])
+        self._include_files.add(include_file)
+
+    def _create_template_context(self):
+        interfaces = []
+        for name in sorted(self._interface_contexts):
+            interfaces.append(self._interface_contexts[name])
+        return {
+            'class': 'V8ContextSnapshotExternalReferences',
+            'interfaces': interfaces,
+            'include_files': sorted(list(self._include_files)),
+        }
+
+    def generate(self):
+        jinja_env = initialize_jinja_env(self._opts.cache_dir)
+        context = self._create_template_context()
+        cpp_template = jinja_env.get_template(TEMPLATE_FILE)
+        cpp_text = cpp_template.render(context)
+        return cpp_text
+
+
+def main():
+    opts, _ = parse_args()
+    # TODO(peria): get rid of |info_provider|
+    info_provider = create_component_info_provider(
+        opts.info_dir, opts.target_component)
+    generator = ExternalReferenceTableGenerator(opts, info_provider)
+
+    idl_files = utilities.read_idl_files_list_from_file(opts.idl_files_list, False)
+    for idl_file in idl_files:
+        generator.process_idl_file(idl_file)
+    output_code = generator.generate()
+    output_path = opts.output
+    write_file(output_code, output_path)
+
+
+if __name__ == '__main__':
+    main()