#!/usr/bin/env python ''' mavlink python parse functions Copyright Andrew Tridgell 2011 Released under GNU GPL version 3 or later ''' import xml.parsers.expat, os, errno, time, sys, operator, mavutil PROTOCOL_0_9 = "0.9" PROTOCOL_1_0 = "1.0" class MAVParseError(Exception): def __init__(self, message, inner_exception=None): self.message = message self.inner_exception = inner_exception self.exception_info = sys.exc_info() def __str__(self): return self.message class MAVField(object): def __init__(self, name, type, print_format, xml, description=''): self.name = name self.name_upper = name.upper() self.description = description self.array_length = 0 self.omit_arg = False self.const_value = None self.print_format = print_format lengths = { 'float' : 4, 'double' : 8, 'char' : 1, 'int8_t' : 1, 'uint8_t' : 1, 'uint8_t_mavlink_version' : 1, 'int16_t' : 2, 'uint16_t' : 2, 'int32_t' : 4, 'uint32_t' : 4, 'int64_t' : 8, 'uint64_t' : 8, } if type=='uint8_t_mavlink_version': type = 'uint8_t' self.omit_arg = True self.const_value = xml.version aidx = type.find("[") if aidx != -1: assert type[-1:] == ']' self.array_length = int(type[aidx+1:-1]) type = type[0:aidx] if type == 'array': type = 'int8_t' if type in lengths: self.type_length = lengths[type] self.type = type elif (type+"_t") in lengths: self.type_length = lengths[type+"_t"] self.type = type+'_t' else: raise MAVParseError("unknown type '%s'" % type) if self.array_length != 0: self.wire_length = self.array_length * self.type_length else: self.wire_length = self.type_length self.type_upper = self.type.upper() def gen_test_value(self, i): '''generate a testsuite value for a MAVField''' if self.const_value: return self.const_value elif self.type == 'float': return 17.0 + self.wire_offset*7 + i elif self.type == 'double': return 123.0 + self.wire_offset*7 + i elif self.type == 'char': return chr(ord('A') + (self.wire_offset + i)%26) elif self.type in [ 'int8_t', 'uint8_t' ]: return (5 + self.wire_offset*67 + i) & 0xFF elif self.type in ['int16_t', 'uint16_t']: return (17235 + self.wire_offset*52 + i) & 0xFFFF elif self.type in ['int32_t', 'uint32_t']: return (963497464 + self.wire_offset*52 + i)&0xFFFFFFFF elif self.type in ['int64_t', 'uint64_t']: return 93372036854775807 + self.wire_offset*63 + i else: raise MAVError('unknown type %s' % self.type) def set_test_value(self): '''set a testsuite value for a MAVField''' if self.array_length: self.test_value = [] for i in range(self.array_length): self.test_value.append(self.gen_test_value(i)) else: self.test_value = self.gen_test_value(0) if self.type == 'char' and self.array_length: v = "" for c in self.test_value: v += c self.test_value = v[:-1] class MAVType(object): def __init__(self, name, id, linenumber, description=''): self.name = name self.name_lower = name.lower() self.linenumber = linenumber self.id = int(id) self.description = description self.fields = [] self.fieldnames = [] class MAVEnumParam(object): def __init__(self, index, description=''): self.index = index self.description = description class MAVEnumEntry(object): def __init__(self, name, value, description='', end_marker=False): self.name = name self.value = value self.description = description self.param = [] self.end_marker = end_marker class MAVEnum(object): def __init__(self, name, linenumber, description=''): self.name = name self.description = description self.entry = [] self.highest_value = 0 self.linenumber = linenumber class MAVXML(object): '''parse a mavlink XML file''' def __init__(self, filename, wire_protocol_version=PROTOCOL_0_9): self.filename = filename self.basename = os.path.basename(filename) if self.basename.lower().endswith(".xml"): self.basename = self.basename[:-4] self.basename_upper = self.basename.upper() self.message = [] self.enum = [] self.parse_time = time.asctime() self.version = 2 self.include = [] self.wire_protocol_version = wire_protocol_version if wire_protocol_version == PROTOCOL_0_9: self.protocol_marker = ord('U') self.sort_fields = False self.little_endian = False self.crc_extra = False elif wire_protocol_version == PROTOCOL_1_0: self.protocol_marker = 0xFE self.sort_fields = True self.little_endian = True self.crc_extra = True else: print("Unknown wire protocol version") print("Available versions are: %s %s" % (PROTOCOL_0_9, PROTOCOL_1_0)) raise MAVParseError('Unknown MAVLink wire protocol version %s' % wire_protocol_version) in_element_list = [] def check_attrs(attrs, check, where): for c in check: if not c in attrs: raise MAVParseError('expected missing %s "%s" attribute at %s:%u' % ( where, c, filename, p.CurrentLineNumber)) def start_element(name, attrs): in_element_list.append(name) in_element = '.'.join(in_element_list) #print in_element if in_element == "mavlink.messages.message": check_attrs(attrs, ['name', 'id'], 'message') self.message.append(MAVType(attrs['name'], attrs['id'], p.CurrentLineNumber)) elif in_element == "mavlink.messages.message.field": check_attrs(attrs, ['name', 'type'], 'field') if 'print_format' in attrs: print_format = attrs['print_format'] else: print_format = None self.message[-1].fields.append(MAVField(attrs['name'], attrs['type'], print_format, self)) elif in_element == "mavlink.enums.enum": check_attrs(attrs, ['name'], 'enum') self.enum.append(MAVEnum(attrs['name'], p.CurrentLineNumber)) elif in_element == "mavlink.enums.enum.entry": check_attrs(attrs, ['name'], 'enum entry') if 'value' in attrs: value = int(attrs['value']) else: value = self.enum[-1].highest_value + 1 if (value > self.enum[-1].highest_value): self.enum[-1].highest_value = value self.enum[-1].entry.append(MAVEnumEntry(attrs['name'], value)) elif in_element == "mavlink.enums.enum.entry.param": check_attrs(attrs, ['index'], 'enum param') self.enum[-1].entry[-1].param.append(MAVEnumParam(attrs['index'])) def end_element(name): in_element = '.'.join(in_element_list) if in_element == "mavlink.enums.enum": # add a ENUM_END self.enum[-1].entry.append(MAVEnumEntry("%s_ENUM_END" % self.enum[-1].name, self.enum[-1].highest_value+1, end_marker=True)) in_element_list.pop() def char_data(data): in_element = '.'.join(in_element_list) if in_element == "mavlink.messages.message.description": self.message[-1].description += data elif in_element == "mavlink.messages.message.field": self.message[-1].fields[-1].description += data elif in_element == "mavlink.enums.enum.description": self.enum[-1].description += data elif in_element == "mavlink.enums.enum.entry.description": self.enum[-1].entry[-1].description += data elif in_element == "mavlink.enums.enum.entry.param": self.enum[-1].entry[-1].param[-1].description += data elif in_element == "mavlink.version": self.version = int(data) elif in_element == "mavlink.include": self.include.append(data) f = open(filename, mode='rb') p = xml.parsers.expat.ParserCreate() p.StartElementHandler = start_element p.EndElementHandler = end_element p.CharacterDataHandler = char_data p.ParseFile(f) f.close() self.message_lengths = [ 0 ] * 256 self.message_crcs = [ 0 ] * 256 self.message_names = [ None ] * 256 self.largest_payload = 0 for m in self.message: m.wire_length = 0 m.fieldnames = [] m.ordered_fieldnames = [] if self.sort_fields: m.ordered_fields = sorted(m.fields, key=operator.attrgetter('type_length'), reverse=True) else: m.ordered_fields = m.fields for f in m.fields: m.fieldnames.append(f.name) for f in m.ordered_fields: f.wire_offset = m.wire_length m.wire_length += f.wire_length m.ordered_fieldnames.append(f.name) f.set_test_value() m.num_fields = len(m.fieldnames) if m.num_fields > 64: raise MAVParseError("num_fields=%u : Maximum number of field names allowed is" % ( m.num_fields, 64)) m.crc_extra = message_checksum(m) self.message_lengths[m.id] = m.wire_length self.message_names[m.id] = m.name self.message_crcs[m.id] = m.crc_extra if m.wire_length > self.largest_payload: self.largest_payload = m.wire_length if m.wire_length+8 > 64: print("Note: message %s is longer than 64 bytes long (%u bytes), which can cause fragmentation since many radio modems use 64 bytes as maximum air transfer unit." % (m.name, m.wire_length+8)) def __str__(self): return "MAVXML for %s from %s (%u message, %u enums)" % ( self.basename, self.filename, len(self.message), len(self.enum)) def message_checksum(msg): '''calculate a 8-bit checksum of the key fields of a message, so we can detect incompatible XML changes''' crc = mavutil.x25crc(msg.name + ' ') for f in msg.ordered_fields: crc.accumulate(f.type + ' ') crc.accumulate(f.name + ' ') if f.array_length: crc.accumulate(chr(f.array_length)) return (crc.crc&0xFF) ^ (crc.crc>>8) def merge_enums(xml): '''merge enums between XML files''' emap = {} for x in xml: newenums = [] for enum in x.enum: if enum.name in emap: emap[enum.name].entry.pop() # remove end marker emap[enum.name].entry.extend(enum.entry) print("Merged enum %s" % enum.name) else: newenums.append(enum) emap[enum.name] = enum x.enum = newenums # sort by value for e in emap: emap[e].entry = sorted(emap[e].entry, key=operator.attrgetter('value'), reverse=False) def check_duplicates(xml): '''check for duplicate message IDs''' merge_enums(xml) msgmap = {} enummap = {} for x in xml: for m in x.message: if m.id in msgmap: print("ERROR: Duplicate message id %u for %s (%s:%u) also used by %s" % ( m.id, m.name, x.filename, m.linenumber, msgmap[m.id])) return True fieldset = set() for f in m.fields: if f.name in fieldset: print("ERROR: Duplicate field %s in message %s (%s:%u)" % ( f.name, m.name, x.filename, m.linenumber)) return True fieldset.add(f.name) msgmap[m.id] = '%s (%s:%u)' % (m.name, x.filename, m.linenumber) for enum in x.enum: for entry in enum.entry: s1 = "%s.%s" % (enum.name, entry.name) s2 = "%s.%s" % (enum.name, entry.value) if s1 in enummap or s2 in enummap: print("ERROR: Duplicate enums %s/%s at %s:%u and %s" % ( s1, entry.value, x.filename, enum.linenumber, enummap.get(s1) or enummap.get(s2))) return True enummap[s1] = "%s:%u" % (x.filename, enum.linenumber) enummap[s2] = "%s:%u" % (x.filename, enum.linenumber) return False def total_msgs(xml): '''count total number of msgs''' count = 0 for x in xml: count += len(x.message) return count def mkdir_p(dir): try: os.makedirs(dir) except OSError as exc: if exc.errno == errno.EEXIST: pass else: raise # check version consistent # add test.xml # finish test suite # printf style error macro, if defined call errors