loxi_front_end/frontend.py

# Copyright 2013, Big Switch Networks, Inc.
#
# LoxiGen is licensed under the Eclipse Public License, version 1.0 (EPL), with
# the following special exception:
#
# LOXI Exception
#
# As a special exception to the terms of the EPL, you may distribute libraries
# generated by LoxiGen (LoxiGen Libraries) under the terms of your choice, provided
# that copyright and licensing notices generated by LoxiGen are not altered or removed
# from the LoxiGen Libraries and the notice provided below is (i) included in
# the LoxiGen Libraries, if distributed in source code form and (ii) included in any
# documentation for the LoxiGen Libraries, if distributed in binary form.
#
# Notice: "Copyright 2013, Big Switch Networks, Inc. This library was generated by the LoxiGen Compiler."
#
# You may not use this file except in compliance with the EPL or LOXI Exception. You may obtain
# a copy of the EPL at:
#
# http://www.eclipse.org/legal/epl-v10.html
#
# 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
# EPL for the specific language governing permissions and limitations
# under the EPL.

import of_g
import loxi_front_end.type_maps as type_maps

class InputError(Exception):
    pass

def create_ofinput(ast):
    """
    Create an OFInput from an AST

    @param ast An AST as returned by loxi_front_end.parser.parse

    @returns An OFInput object
    """

    ofinput = of_g.OFInput()

    # Now for each structure, generate lists for each member
    for s in ast:
        if s[0] == 'struct':
            name = s[1].replace("ofp_", "of_", 1)
            members = [dict(m_type=x[0], name=x[1]) for x in s[2]]
            ofinput.classes[name] = members
            ofinput.ordered_classes.append(name)
            if name in type_maps.inheritance_map:
                # Clone class into header class and add to list
                ofinput.classes[name + "_header"] = members[:]
                ofinput.ordered_classes.append(name + "_header")
        if s[0] == 'enum':
            name = s[1]
            members = s[2]
            ofinput.enums[name] = [(x[0], x[1]) for x in members]
        elif s[0] == 'metadata':
            if s[1] == 'version':
                if s[2] == 'any':
                    ofinput.wire_versions.update(of_g.wire_ver_map.keys())
                elif int(s[2]) in of_g.supported_wire_protos:
                    ofinput.wire_versions.add(int(s[2]))
                else:
                    raise InputError("Unrecognized wire protocol version %s" % repr(s[2]))
                found_wire_version = True

    if not ofinput.wire_versions:
        raise InputError("Missing #version metadata")

    return ofinput