cpp/codegen/codegen.py

"""
Copyright 2018-present, Facebook, Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
from __future__ import unicode_literals

import abc
import re
from collections import namedtuple

SIGNED_SOURCE = "".join(["@", "generated", " ", "SignedSource", "<<>>"])


class Language(object, metaclass=abc.ABCMeta):
    CPP = 1
    JAVA = 2

    @staticmethod
    def is_valid(num):
        return num in [Language.CPP, Language.JAVA]


class MemoryDescription(namedtuple("MemoryDescription", ["fields", "typename"])):
    TYPE_ID = 1

    def __init__(self, **kwargs):
        super(MemoryDescription, self).__init__(self, **kwargs)

        if self.fields is None:
            raise ValueError("fields is required")

        if self.typename is None:
            raise ValueError("typename is required")

        self.type_id = MemoryDescription.TYPE_ID
        MemoryDescription.TYPE_ID += 1


class EntryDescription(namedtuple("EntryDescription", ["id", "name", "memory_format"])):
    def __init__(self, **kwargs):
        super(EntryDescription, self).__init__(self, **kwargs)

        if self.id is None:
            raise ValueError("id is required")

        if self.name is None:
            raise ValueError("name is required")

        if self.memory_format is None:
            raise ValueError("memory_format is required")

        if not isinstance(self.memory_format, MemoryDescription):
            raise ValueError("memory_format must be a MemoryDescription")


class Codegen(object, metaclass=abc.ABCMeta):
    @abc.abstractmethod
    def generate(self):
        pass

    @abc.abstractmethod
    def preferred_filename(self):
        pass

    @staticmethod
    def indent(text):
        return re.sub("^", " " * 2, text, flags=re.MULTILINE)