Add code generation for ConditionalFeatures bindings code

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

+#!/usr/bin/python
+#
+# 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.
+
+# This script reads the global interface data collected by
+# compute_interfaces_info_overall.py, and writes out the code which adds
+# bindings for origin-trial-enabled features at runtime.
+
+# pylint: disable=W0403
+
+import optparse
+import os
+import posixpath
+import sys
+from collections import defaultdict
+
+from code_generator import (initialize_jinja_env, normalize_and_sort_includes,
+                            render_template)
+from idl_reader import IdlReader
+from utilities import (create_component_info_provider, write_file,
+                       idl_filename_to_component)
+from v8_utilities import v8_class_name, v8_class_name_or_partial, uncapitalize
+
+# Make sure extension is .py, not .pyc or .pyo, so doesn't depend on caching
+MODULE_PYNAME = os.path.splitext(os.path.basename(__file__))[0] + '.py'
+
+
+def get_install_functions(interfaces, feature_names):
+    return [
+        {"condition": 'OriginTrials::%sEnabled' % uncapitalize(feature_name),
+         "name": feature_name,
+         "install_method": "install%s" % feature_name,
+         "v8_class": interface_info[1],
+         "v8_class_or_partial": interface_info[2]}

[haraken, 2017/07/17 07:28:17]

What is [1] and [2]? Is there any more readable way to access the entry?

[iclelland, 2017/07/17 14:24:21]

I created a namedtuple subclass to allow these items to be indexed by name
instead. (I would have used a desructuring bind, but that makes the code around
line 144 much more complicated.)

+        for feature_name in feature_names
+        for interface_info in interfaces]
+
+
+def get_conditional_feature_names_from_interface(interface):
+    feature_names = set()
+    if ('OriginTrialEnabled' in interface.extended_attributes and
+            interface.is_partial):
+        feature_names.add(interface.extended_attributes['OriginTrialEnabled'])
+    for operation in interface.operations:
+        if 'OriginTrialEnabled' in operation.extended_attributes:
+            feature_names.add(
+                operation.extended_attributes['OriginTrialEnabled'])
+    for attribute in interface.attributes:
+        if 'OriginTrialEnabled' in attribute.extended_attributes:
+            feature_names.add(
+                attribute.extended_attributes['OriginTrialEnabled'])
+    return list(feature_names)
+
+
+def read_idl_file(reader, idl_filename):
+    interfaces = reader.read_idl_file(idl_filename).interfaces
+    assert len(interfaces) == 1
+    return interfaces.items()[0][1]

[haraken, 2017/07/17 07:28:17]

Ditto.

[iclelland, 2017/07/17 14:24:21]

Changed this to values(), since we don't actually care about the key. Added a
comment that we're just returning the first (and only) value from the
dictionary.

+
+
+def interface_is_global(interface):
+    return ('Global' in interface.extended_attributes or
+            'PrimaryGlobal' in interface.extended_attributes)
+
+
+def conditional_features_info(info_provider, reader, idl_filenames, target_component):
+    """Read a set of IDL files and compile the mapping between interfaces and
+    the conditional features defined on them.
+
+    Returns a tuple (features_for_type, types_for_feature, includes):
+      - features_for_type is a mapping of interface->feature
+      - types_for_feature is the reverse mapping: feature->interface
+      - includes is a set of header files which need to be included in the
+          generated implementation code.
+    """
+    features_for_type = defaultdict(set)
+    types_for_feature = defaultdict(set)
+    includes = set()
+
+    for idl_filename in idl_filenames:
+        interface = read_idl_file(reader, idl_filename)
+        feature_names = get_conditional_feature_names_from_interface(interface)
+        if feature_names:
+            is_global = interface_is_global(interface)
+            if interface.is_partial:
+                # For partial interfaces, we need to generate different
+                # includes if the parent interface is in a different
+                # component.
+                parent_interface_info = info_provider.interfaces_info[interface.name]
+                parent_interface = read_idl_file(
+                    reader, parent_interface_info.get('full_path'))
+                is_global = is_global or interface_is_global(parent_interface)
+                parent_component = idl_filename_to_component(
+                    parent_interface_info.get('full_path'))
+            if interface.is_partial and target_component != parent_component:
+                includes.add('bindings/%s/v8/V8%s.h' %
+                             (parent_component, interface.name))
+                includes.add('bindings/%s/v8/V8%sPartial.h' %
+                             (target_component, interface.name))
+            else:
+                includes.add('bindings/%s/v8/V8%s.h' %
+                             (target_component, interface.name))
+                # If this is a partial interface in the same component as
+                # its parent, then treat it as a non-partial interface.
+                interface.is_partial = False
+            interface_info = (interface.name,
+                              v8_class_name(interface),
+                              v8_class_name_or_partial(interface),
+                              is_global)
+            for feature_name in feature_names:
+                features_for_type[interface_info].add(feature_name)
+                types_for_feature[feature_name].add(interface_info)
+
+    return features_for_type, types_for_feature, includes
+
+
+def conditional_features_context(generator_name, feature_info):
+    context = {'code_generator': generator_name}
+
+    # Unpack the feature info tuple.
+    features_for_type, types_for_feature, includes = feature_info
+
+    # Add includes needed for cpp code and normalize.
+    includes.update([
+        "core/context_features/ContextFeatureSettings.h",
+        "core/dom/ExecutionContext.h",
+        "core/frame/Frame.h",
+        "core/origin_trials/OriginTrials.h",
+        "platform/bindings/ConditionalFeatures.h",
+        "platform/bindings/ScriptState.h",
+        # TODO(iclelland): Remove the need to explicitly include this; it is
+        # here because the ContextFeatureSettings code needs it.
+        "bindings/core/v8/V8Window.h",
+    ])
+    context['includes'] = normalize_and_sort_includes(includes)
+
+    # For each interface, collect a list of bindings installation functions to
+    # call, organized by conditional feature.
+    context['installers_by_interface'] = [
+        {"name": interface_info[0],
+         "is_global": interface_info[3],
+         "v8_class": interface_info[1],

[haraken, 2017/07/17 07:28:17]

Ditto.

[iclelland, 2017/07/17 14:24:21]

Namedtuple makes this more readable now.

+         "installers": get_install_functions([interface_info], feature_names)}
+        for interface_info, feature_names in features_for_type.items()]
+    context['installers_by_interface'].sort(key=lambda x: x['name'])
+
+    # For each conditional feature, collect a list of bindings installation
+    # functions to call, organized by interface.
+    context['installers_by_feature'] = [
+        {"name": feature_name,
+         "installers": get_install_functions(interfaces, [feature_name])}
+        for feature_name, interfaces in types_for_feature.items()]
+    context['installers_by_feature'].sort(key=lambda x: x['name'])
+
+    return context
+
+
+def parse_options():
+    parser = optparse.OptionParser()
+    parser.add_option('--cache-directory',
+                      help='cache directory, defaults to output directory')
+    parser.add_option('--output-directory')
+    parser.add_option('--info-dir')
+    parser.add_option('--target-component',
+                      type='choice',
+                      choices=['Core', 'Modules'],
+                      help='target component to generate code')
+    parser.add_option('--idl-files-list')
+
+    options, _ = parser.parse_args()
+    if options.output_directory is None:
+        parser.error('Must specify output directory using --output-directory.')
+    return options
+
+
+def generate_conditional_features(info_provider, options, idl_filenames):
+    reader = IdlReader(info_provider.interfaces_info, options.cache_directory)
+    jinja_env = initialize_jinja_env(options.cache_directory)
+
+    # Extract the bidirectional mapping of conditional features <-> interfaces
+    # from the global info provider and the supplied list of IDL files.
+    feature_info = conditional_features_info(info_provider,
+                                             reader, idl_filenames,
+                                             options.target_component.lower())
+
+    # Convert that mapping into the context required for the Jinja2 templates.
+    template_context = conditional_features_context(
+        MODULE_PYNAME, feature_info)
+
+    # Generate and write out the header file
+    header_text = render_template(jinja_env.get_template(
+        "ConditionalFeaturesFor%s.h.tmpl" % options.target_component.title()), template_context)
+    header_path = posixpath.join(options.output_directory,
+                                 "ConditionalFeaturesFor%s.h" % options.target_component.title())
+    write_file(header_text, header_path)
+
+    # Generate and write out the implementation file
+    cpp_text = render_template(jinja_env.get_template(
+        "ConditionalFeaturesFor%s.cpp.tmpl" % options.target_component.title()), template_context)
+    cpp_path = posixpath.join(options.output_directory,
+                              "ConditionalFeaturesFor%s.cpp" % options.target_component.title())
+    write_file(cpp_text, cpp_path)
+
+
+def main():
+    options = parse_options()
+
+    info_provider = create_component_info_provider(
+        os.path.normpath(options.info_dir), options.target_component.lower())
+    idl_filenames = map(str.strip, open(options.idl_files_list))
+
+    generate_conditional_features(info_provider, options, idl_filenames)
+    return 0
+
+
+if __name__ == '__main__':
+    sys.exit(main())