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# 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.
from generic_utils import find
from collections import namedtuple
import copy
import loxi_globals
import loxi_front_end.frontend_ir as ir
class InputError(Exception):
pass
FrontendCtx = namedtuple("FrontendCtx", ("used_enums"))
def get_type(t_ast, ctx):
if t_ast[0] == "enum":
ctx.used_enums.add(t_ast[1])
return t_ast[1]
def create_member(m_ast, ctx):
if m_ast[0] == 'pad':
return ir.OFPadMember(length=m_ast[1])
elif m_ast[0] == 'type':
return ir.OFTypeMember(name=m_ast[2], oftype=get_type(m_ast[1], ctx), value=m_ast[3])
elif m_ast[0] == 'data':
if m_ast[2] == 'length' or m_ast[2] == 'len': # Should be moved to parser
return ir.OFLengthMember(name=m_ast[2], oftype=get_type(m_ast[1], ctx))
elif m_ast[2] == 'actions_len':
# HACK only usage so far
return ir.OFFieldLengthMember(name=m_ast[2], oftype=get_type(m_ast[1], ctx), field_name='actions')
else:
return ir.OFDataMember(name=m_ast[2], oftype=get_type(m_ast[1], ctx))
elif m_ast[0] == 'discriminator':
return ir.OFDiscriminatorMember(name=m_ast[2], oftype=get_type(m_ast[1], ctx))
else:
raise InputError("Dont know how to create member: %s" % m_ast[0])
def create_ofinput(filename, ast):
"""
Create an OFInput from an AST
@param ast An AST as returned by loxi_front_end.parser.parse
@returns An OFInput object
"""
ctx = FrontendCtx(set())
ofinput = ir.OFInput(filename, wire_versions=set(), classes=[], enums=[])
for decl_ast in ast:
if decl_ast[0] == 'struct':
# 0: "struct"
# 1: name
# 2: potentially list of [param_name, param_value]
# 3: super_class or None
# 4: list of members
superclass = decl_ast[3]
members = [create_member(m_ast, ctx) for m_ast in decl_ast[4]]
discriminators = [ m for m in members if isinstance(m, ir.OFDiscriminatorMember) ]
if len(discriminators) > 1:
raise InputError("%s: Cannot support more than one discriminator by class - got %s" %
(decl_ast[1], repr(discriminators)))
ofclass = ir.OFClass(name=decl_ast[1], members=members, superclass=superclass,
virtual = len(discriminators) > 0,
params = { param: value for param, value in decl_ast[2] })
ofinput.classes.append(ofclass)
if decl_ast[0] == 'enum':
# 0: "enum"
# 1: name
# 2: potentially list of [param_name, param_value]
# 3: list of [constant_name, constant_value]+
enum = ir.OFEnum(name=decl_ast[1],
entries=[ir.OFEnumEntry(name=x[0], value=x[2], params={param:value for param, value in x[1] }) for x in decl_ast[3]],
params = { param: value for param, value in decl_ast[2] }
)
ofinput.enums.append(enum)
elif decl_ast[0] == 'metadata':
if decl_ast[1] == 'version':
if decl_ast[2] == 'any':
ofinput.wire_versions.update(v.wire_version for v in loxi_globals.OFVersions.all_supported)
elif int(decl_ast[2]) in loxi_globals.OFVersions.wire_version_map:
ofinput.wire_versions.add(int(decl_ast[2]))
else:
raise InputError("Unrecognized wire protocol version %r" % decl_ast[2])
found_wire_version = True
if not ofinput.wire_versions:
raise InputError("Missing #version metadata")
return ofinput