Source/bindings/scripts/code_generator_v8.py

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"""Generate Blink V8 bindings (.h and .cpp files).

Input: An object of class IdlDefinitions, containing an IDL interface X
Output: V8X.h and V8X.cpp
"""

import os
import posixpath
import sys

# jinja2 is in chromium's third_party directory.
module_path, module_name = os.path.split(__file__)
third_party = os.path.join(module_path, os.pardir, os.pardir, os.pardir, os.pardir)
sys.path.append(third_party)
import jinja2

templates_dir = os.path.join(module_path, os.pardir, 'templates')

import v8_callback_interface
import v8_interface
from v8_utilities import cpp_class_name, generate_conditional_string, v8_class_name


class CodeGeneratorV8:
    def __init__(self, definitions, interface_name, output_directory, relative_dir_posix, idl_directories, verbose=False):
        self.idl_definitions = definitions
        self.interface_name = interface_name
        self.idl_directories = idl_directories
        self.output_directory = output_directory
        self.verbose = verbose
        # FIXME: remove definitions check when remove write_dummy_header_and_cpp
        if not definitions:
            return
        try:
            self.interface = definitions.interfaces[interface_name]
        except KeyError:
            raise Exception('%s not in IDL definitions' % interface_name)
        if self.interface.is_callback:
            header_template_filename = 'callback_interface.h'
            cpp_template_filename = 'callback_interface.cpp'
            self.generate_contents = v8_callback_interface.generate_callback_interface
        else:
            header_template_filename = 'interface.h'
            cpp_template_filename = 'interface.cpp'
            self.generate_contents = v8_interface.generate_interface
        # FIXME: update to Jinja 2.7 and use:
        # keep_trailing_newline=True,  # newline-terminate generated files
        # lstrip_blocks=True,  # so can indent control flow tags
        jinja_env = jinja2.Environment(
            loader=jinja2.FileSystemLoader(templates_dir),
            trim_blocks=True)
        self.header_template = jinja_env.get_template(header_template_filename)
        self.cpp_template = jinja_env.get_template(cpp_template_filename)

        class_name = cpp_class_name(self.interface)
        self.include_for_cpp_class = posixpath.join(relative_dir_posix, class_name + '.h')

    def write_dummy_header_and_cpp(self):
        # FIXME: fix GYP so these files aren't needed and remove this method
        target_interface_name = self.interface_name
        header_basename = 'V8%s.h' % target_interface_name
        cpp_basename = 'V8%s.cpp' % target_interface_name
        contents = """/*
    This file is generated just to tell build scripts that {header_basename} and
    {cpp_basename} are created for {target_interface_name}.idl, and thus
    prevent the build scripts from trying to generate {header_basename} and
    {cpp_basename} at every build. This file must not be tried to compile.
*/
""".format(**locals())
        self.write_file(header_basename, contents)
        self.write_file(cpp_basename, contents)

    def write_header_and_cpp(self):
        interface = self.interface
        template_contents = self.generate_contents(interface)
        template_contents['conditional_string'] = generate_conditional_string(interface)
        template_contents['header_includes'].add(self.include_for_cpp_class)
        template_contents['header_includes'] = sorted(template_contents['header_includes'])
        template_contents['cpp_includes'] = sorted(template_contents['cpp_includes'])

        header_basename = v8_class_name(interface) + '.h'
        header_file_text = self.header_template.render(template_contents)
        self.write_file(header_basename, header_file_text)

        cpp_basename = v8_class_name(interface) + '.cpp'
        cpp_file_text = self.cpp_template.render(template_contents)
        self.write_file(cpp_basename, cpp_file_text)

    def write_file(self, basename, file_text):
        filename = os.path.join(self.output_directory, basename)
        with open(filename, 'w') as output_file:
            output_file.write(file_text)