#!/usr/bin/env python
# Copyright 2012 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.
# Format for the JSON schema file:
# {
# "type_name": "DesiredCStructName",
# "headers": [ // Optional list of headers to be included by the .h.
# "path/to/header.h"
# ],
# "schema": [ // Fields of the generated structure.
# {
# "field": "my_enum_field",
# "type": "enum", // Either: int, string, string16, enum, array.
# "default": "RED", // Optional. Cannot be used for array.
# "ctype": "Color" // Only for enum, specify the C type.
# },
# {
# "field": "my_int_array_field", // my_int_array_field_size will also
# "type": "array", // be generated.
# "contents": {
# "type": "int" // Either: int, string, string16, enum, array.
# }
# },
# ...
# ]
# }
#
# Format for the JSON description file:
# {
# "int_variables": { // An optional list of constant int variables.
# "kDesiredConstantName": 45
# },
# "elements": { // All the elements for which to create static
# // initialization code in the .cc file.
# "my_const_variable": {
# "my_int_field": 10,
# "my_string_field": "foo bar",
# "my_enum_field": "BLACK",
# "my_int_array_field": [ 1, 2, 3, 5, 7 ],
# },
# "my_other_const_variable": {
# ...
# }
# }
# }
import json
from datetime import datetime
import os.path
import sys
import optparse
import re
_script_path = os.path.realpath(__file__)
sys.path.insert(0, os.path.normpath(_script_path + "/../../json_comment_eater"))
try:
import json_comment_eater
finally:
sys.path.pop(0)
import struct_generator
import element_generator
HEAD = """// Copyright %d 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.
// GENERATED FROM THE SCHEMA DEFINITION AND DESCRIPTION IN
// %s
// %s
// DO NOT EDIT.
"""
def _GenerateHeaderGuard(h_filename):
"""Generates the string used in #ifndef guarding the header file.
"""
result = re.sub('[%s\\\\.]' % os.sep, '_', h_filename.upper())
return re.sub('^_*', '', result) + '_' # Remove leading underscores.
def _GenerateH(basepath, fileroot, head, namespace, schema, description):
"""Generates the .h file containing the definition of the structure specified
by the schema.
Args:
basepath: The base directory in which files are generated.
fileroot: The filename and path, relative to basepath, of the file to
create, without an extension.
head: The string to output as the header of the .h file.
namespace: A string corresponding to the C++ namespace to use.
schema: A dict containing the schema. See comment at the top of this file.
description: A dict containing the description. See comment at the top of
this file.
"""
h_filename = fileroot + '.h'
with open(os.path.join(basepath, h_filename), 'w') as f:
f.write(head)
header_guard = _GenerateHeaderGuard(h_filename)
f.write('#ifndef %s\n' % header_guard)
f.write('#define %s\n' % header_guard)
f.write('\n')
f.write('#include <cstddef>\n')
f.write('\n')
for header in schema.get('headers', []):
f.write('#include "%s"\n' % header)
f.write('\n')
if namespace:
f.write('namespace %s {\n' % namespace)
f.write('\n')
f.write(struct_generator.GenerateStruct(
schema['type_name'], schema['schema']))
f.write('\n')
for var_name, value in description.get('int_variables', []).items():
f.write('extern const int %s;\n' % var_name)
f.write('\n')
for element_name, element in description['elements'].items():
f.write('extern const %s %s;\n' % (schema['type_name'], element_name))
if namespace:
f.write('\n')
f.write('} // namespace %s\n' % namespace)
f.write('\n')
f.write( '#endif // %s\n' % header_guard)
def _GenerateCC(basepath, fileroot, head, namespace, schema, description):
"""Generates the .cc file containing the static initializers for the
of the elements specified in the description.
Args:
basepath: The base directory in which files are generated.
fileroot: The filename and path, relative to basepath, of the file to
create, without an extension.
head: The string to output as the header of the .cc file.
namespace: A string corresponding to the C++ namespace to use.
schema: A dict containing the schema. See comment at the top of this file.
description: A dict containing the description. See comment at the top of
this file.
"""
with open(os.path.join(basepath, fileroot + '.cc'), 'w') as f:
f.write(head)
f.write('#include "%s"\n' % (fileroot + '.h'))
f.write('\n')
if namespace:
f.write('namespace %s {\n' % namespace)
f.write('\n')
f.write(element_generator.GenerateElements(schema['type_name'],
schema['schema'], description))
if namespace:
f.write('\n')
f.write('} // namespace %s\n' % namespace)
def _Load(filename):
"""Loads a JSON file int a Python object and return this object.
"""
# TODO(beaudoin): When moving to Python 2.7 use object_pairs_hook=OrderedDict.
with open(filename, 'r') as handle:
result = json.loads(json_comment_eater.Nom(handle.read()))
return result
if __name__ == '__main__':
parser = optparse.OptionParser(
description='Generates an C++ array of struct from a JSON description.',
usage='usage: %prog [option] -s schema description')
parser.add_option('-b', '--destbase',
help='base directory of generated files.')
parser.add_option('-d', '--destdir',
help='directory to output generated files, relative to destbase.')
parser.add_option('-n', '--namespace',
help='C++ namespace for generated files. e.g search_providers.')
parser.add_option('-s', '--schema', help='path to the schema file, '
'mandatory.')
(opts, args) = parser.parse_args()
if not opts.schema:
parser.error('You must specify a --schema.')
description_filename = os.path.normpath(args[0])
root, ext = os.path.splitext(description_filename)
shortroot = os.path.split(root)[1]
if opts.destdir:
output_root = os.path.join(os.path.normpath(opts.destdir), shortroot)
else:
output_root = shortroot
if opts.destbase:
basepath = os.path.normpath(opts.destbase)
else:
basepath = ''
schema = _Load(opts.schema)
description = _Load(description_filename)
head = HEAD % (datetime.now().year, opts.schema, description_filename)
_GenerateH(basepath, output_root, head, opts.namespace, schema, description)
_GenerateCC(basepath, output_root, head, opts.namespace, schema, description)