source: mainline/tools/xstruct.py@ 0516fd7

#
# Copyright (c) 2008 Martin Decky
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# - Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
# - Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
# - The name of the author may not be used to endorse or promote products
#   derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
"""
Convert descriptive structure definitions to structure object
"""

import struct

class Struct:
        def size(self):
                return struct.calcsize(self._format_)
        
        def pack(self):
                list = []
                for variable in self._list_:
                        list.append(self.__dict__[variable])
                
                return struct.pack(self._format_, *list)

def create(definition):
        "Create structure object"
        
        tokens = definition.split(None)
        
        # Initial byte order tag
        format = {
                "little:":  lambda: "<",
                "big:":     lambda: ">",
                "network:": lambda: "!"
        }[tokens[0]]()
        inst = Struct()
        list = []
        
        # Member tags
        comment = False
        variable = False
        for token in tokens[1:]:
                if (comment):
                        if (token == "*/"):
                                comment = False
                        continue
                
                if (variable):
                        inst.__dict__[token] = None
                        list.append(token)
                        variable = False
                        continue
                
                if (token == "/*"):
                        comment = True
                elif (token[0:8] == "padding["):
                        size = token[8:].split("]")[0]
                        format += "%dx" % int(size)
                elif (token[0:5] == "char["):
                        size = token[5:].split("]")[0]
                        format += "%ds" % int(size)
                        variable = True
                else:
                        format += {
                                "uint8_t":  lambda: "B",
                                "uint16_t": lambda: "H",
                                "uint32_t": lambda: "L",
                                "uint64_t": lambda: "Q",
                                
                                "int8_t":   lambda: "b",
                                "int16_t":  lambda: "h",
                                "int32_t":  lambda: "l",
                                "int64_t":  lambda: "q"
                        }[token]()
                        variable = True
        
        inst.__dict__['_format_'] = format
        inst.__dict__['_list_'] = list
        return inst