1 '''Generate header file for nanopb from a ProtoBuf FileDescriptorSet.'''
3 import google.protobuf.descriptor_pb2 as descriptor
7 # Values are tuple (c type, pb ltype)
8 FieldD = descriptor.FieldDescriptorProto
10 FieldD.TYPE_BOOL: ('bool', 'PB_LTYPE_VARINT'),
11 FieldD.TYPE_DOUBLE: ('double', 'PB_LTYPE_FIXED'),
12 FieldD.TYPE_FIXED32: ('uint32_t', 'PB_LTYPE_FIXED'),
13 FieldD.TYPE_FIXED64: ('uint64_t', 'PB_LTYPE_FIXED'),
14 FieldD.TYPE_FLOAT: ('float', 'PB_LTYPE_FIXED'),
15 FieldD.TYPE_INT32: ('int32_t', 'PB_LTYPE_VARINT'),
16 FieldD.TYPE_INT64: ('int64_t', 'PB_LTYPE_VARINT'),
17 FieldD.TYPE_SFIXED32: ('int32_t', 'PB_LTYPE_FIXED'),
18 FieldD.TYPE_SFIXED64: ('int64_t', 'PB_LTYPE_FIXED'),
19 FieldD.TYPE_SINT32: ('int32_t', 'PB_LTYPE_SVARINT'),
20 FieldD.TYPE_SINT64: ('int64_t', 'PB_LTYPE_SVARINT'),
21 FieldD.TYPE_UINT32: ('uint32_t', 'PB_LTYPE_VARINT'),
22 FieldD.TYPE_UINT64: ('uint64_t', 'PB_LTYPE_VARINT')
26 '''Keeps a set of nested names and formats them to C identifier.
27 You can subclass this with your own implementation.
29 def __init__(self, parts = ()):
30 if isinstance(parts, Names):
32 self.parts = tuple(parts)
35 return '_'.join(self.parts)
37 def __add__(self, other):
38 if isinstance(other, (str, unicode)):
39 return Names(self.parts + (other,))
40 elif isinstance(other, tuple):
41 return Names(self.parts + other)
43 raise ValueError("Name parts should be of type str")
45 def names_from_type_name(type_name):
46 '''Parse Names() from FieldDescriptorProto type_name'''
47 if type_name[0] != '.':
48 raise NotImplementedError("Lookup of non-absolute type names is not supported")
49 return Names(type_name[1:].split('.'))
52 def __init__(self, names, desc):
53 '''desc is EnumDescriptorProto'''
54 self.names = names + desc.name
55 self.values = [(self.names + x.name, x.number) for x in desc.value]
58 result = 'typedef enum {\n'
59 result += ',\n'.join([" %s = %d" % x for x in self.values])
60 result += '\n} %s;' % self.names
64 def __init__(self, struct_name, desc):
65 '''desc is FieldDescriptorProto'''
66 self.tag = desc.number
67 self.struct_name = struct_name
74 # Parse nanopb-specific field options
75 if desc.options.HasExtension(nanopb_pb2.nanopb):
76 ext = desc.options.Extensions[nanopb_pb2.nanopb]
77 if ext.HasField("max_size"):
78 self.max_size = ext.max_size
79 if ext.HasField("max_count"):
80 self.max_count = ext.max_count
82 if desc.HasField('default_value'):
83 self.default = desc.default_value
86 # HTYPE is the high-order nibble of nanopb field description,
87 # defining whether value is required/optional/repeated.
89 if desc.label == FieldD.LABEL_REQUIRED:
90 self.htype = 'PB_HTYPE_REQUIRED'
91 elif desc.label == FieldD.LABEL_OPTIONAL:
92 self.htype = 'PB_HTYPE_OPTIONAL'
93 elif desc.label == FieldD.LABEL_REPEATED:
94 if self.max_count is None:
97 self.htype = 'PB_HTYPE_ARRAY'
98 self.array_decl = '[%d]' % self.max_count
100 raise NotImplementedError(desc.label)
102 # Decide LTYPE and CTYPE
103 # LTYPE is the low-order nibble of nanopb field description,
104 # defining how to decode an individual value.
105 # CTYPE is the name of the c type to use in the struct.
106 if datatypes.has_key(desc.type):
107 self.ctype, self.ltype = datatypes[desc.type]
108 elif desc.type == FieldD.TYPE_ENUM:
109 self.ltype = 'PB_LTYPE_VARINT'
110 self.ctype = names_from_type_name(desc.type_name)
111 self.default = Names(self.ctype) + self.default
112 elif desc.type == FieldD.TYPE_STRING:
113 self.ltype = 'PB_LTYPE_STRING'
114 if self.max_size is None:
118 self.array_decl += '[%d]' % self.max_size
119 elif desc.type == FieldD.TYPE_BYTES:
120 self.ltype = 'PB_LTYPE_BYTES'
121 if self.max_size is None:
124 self.ctype = self.struct_name + self.name + 't'
125 elif desc.type == FieldD.TYPE_MESSAGE:
126 self.ltype = 'PB_LTYPE_SUBMESSAGE'
127 self.ctype = self.submsgname = names_from_type_name(desc.type_name)
129 raise NotImplementedError(desc.type)
132 self.htype = 'PB_HTYPE_CALLBACK'
133 self.ctype = 'pb_callback_t'
136 def __cmp__(self, other):
137 return cmp(self.tag, other.tag)
140 if self.htype == 'PB_HTYPE_OPTIONAL':
141 result = ' bool has_' + self.name + ';\n'
142 elif self.htype == 'PB_HTYPE_ARRAY':
143 result = ' size_t ' + self.name + '_count;\n'
146 result += ' %s %s%s;' % (self.ctype, self.name, self.array_decl)
150 '''Return definitions for any special types this field might need.'''
151 if self.ltype == 'PB_LTYPE_BYTES' and self.max_size is not None:
152 result = 'typedef struct {\n'
153 result += ' size_t size;\n'
154 result += ' uint8_t bytes[%d];\n' % self.max_size
155 result += '} %s;\n' % self.ctype
160 def default_decl(self, declaration_only = False):
161 '''Return definition for this field's default value.'''
162 if self.default is None:
165 if self.ltype == 'PB_LTYPE_STRING':
167 if self.max_size is None:
168 return None # Not implemented
170 array_decl = '[%d]' % (self.max_size + 1)
171 default = str(self.default).encode('string_escape')
172 default = default.replace('"', '\\"')
173 default = '"' + default + '"'
174 elif self.ltype == 'PB_LTYPE_BYTES':
175 data = self.default.decode('string_escape')
176 data = ['0x%02x' % ord(c) for c in data]
178 if self.max_size is None:
179 return None # Not implemented
183 default = '{%d, {%s}}' % (len(data), ','.join(data))
186 ctype, default = self.ctype, self.default
190 return 'extern const %s %s_default%s;' % (ctype, self.struct_name + self.name, array_decl)
192 return 'const %s %s_default%s = %s;' % (ctype, self.struct_name + self.name, array_decl, default)
194 def pb_field_t(self, prev_field_name):
195 '''Return the pb_field_t initializer to use in the constant array.
196 prev_field_name is the name of the previous field or None.
198 result = ' {%d, ' % self.tag
200 if self.ltype is not None:
201 result += ' | ' + self.ltype
204 if prev_field_name is None:
205 result += ' offsetof(%s, %s),' % (self.struct_name, self.name)
207 result += ' pb_delta_end(%s, %s, %s),' % (self.struct_name, self.name, prev_field_name)
209 if self.htype == 'PB_HTYPE_OPTIONAL':
210 result += '\n pb_delta(%s, has_%s, %s),' % (self.struct_name, self.name, self.name)
211 elif self.htype == 'PB_HTYPE_ARRAY':
212 result += '\n pb_delta(%s, %s_count, %s),' % (self.struct_name, self.name, self.name)
217 if self.htype == 'PB_HTYPE_ARRAY':
218 result += '\n pb_membersize(%s, %s[0]),' % (self.struct_name, self.name)
219 result += ('\n pb_membersize(%s, %s) / pb_membersize(%s, %s[0]),'
220 % (self.struct_name, self.name, self.struct_name, self.name))
221 elif self.ltype == 'PB_LTYPE_BYTES':
222 result += '\n pb_membersize(%s, bytes),' % self.ctype
225 result += '\n pb_membersize(%s, %s),' % (self.struct_name, self.name)
228 if self.ltype == 'PB_LTYPE_SUBMESSAGE':
229 result += '\n &%s_fields}' % self.submsgname
230 elif self.default is None or self.htype == 'PB_HTYPE_CALLBACK':
233 result += '\n &%s_default}' % (self.struct_name + self.name)
238 def __init__(self, names, desc):
240 self.fields = [Field(self.name, f) for f in desc.field]
241 self.ordered_fields = self.fields[:]
242 self.ordered_fields.sort()
244 def __cmp__(self, other):
245 '''Sort messages so that submessages are declared before the message
248 if self.refers_to(other.name):
250 elif other.refers_to(self.name):
255 def refers_to(self, name):
256 '''Returns True if this message uses the specified type as field type.'''
257 for field in self.fields:
258 if str(field.ctype) == str(name):
263 result = 'typedef struct {\n'
264 result += '\n'.join([str(f) for f in self.ordered_fields])
265 result += '\n} %s;' % self.name
270 for field in self.fields:
271 types = field.types()
272 if types is not None:
273 result += types + '\n'
276 def default_decl(self, declaration_only = False):
278 for field in self.fields:
279 default = field.default_decl(declaration_only)
280 if default is not None:
281 result += default + '\n'
284 def fields_declaration(self):
285 result = 'extern const pb_field_t %s_fields[%d];' % (self.name, len(self.fields) + 1)
288 def fields_definition(self):
289 result = 'const pb_field_t %s_fields[%d] = {\n' % (self.name, len(self.fields) + 1)
292 for field in self.ordered_fields:
293 result += field.pb_field_t(prev)
297 result += ' PB_LAST_FIELD\n};'
300 def iterate_messages(desc, names = Names()):
301 '''Recursively find all messages. For each, yield name, DescriptorProto.'''
302 if hasattr(desc, 'message_type'):
303 submsgs = desc.message_type
305 submsgs = desc.nested_type
307 for submsg in submsgs:
308 sub_names = names + submsg.name
309 yield sub_names, submsg
311 for x in iterate_messages(submsg, sub_names):
314 def parse_file(fdesc):
315 '''Takes a FileDescriptorProto and returns tuple (enum, messages).'''
320 for enum in fdesc.enum_type:
321 enums.append(Enum(Names(), enum))
323 for names, message in iterate_messages(fdesc):
324 messages.append(Message(names, message))
325 for enum in message.enum_type:
326 enums.append(Enum(names, enum))
328 return enums, messages
330 def generate_header(headername, enums, messages):
331 '''Generate content for a header file.
332 Generates strings, which should be concatenated and stored to file.
335 yield '/* Automatically generated nanopb header */\n'
337 symbol = headername.replace('.', '_').upper()
338 yield '#ifndef _PB_%s_\n' % symbol
339 yield '#define _PB_%s_\n' % symbol
340 yield '#include <pb.h>\n\n'
342 yield '/* Enum definitions */\n'
344 yield str(enum) + '\n\n'
346 yield '/* Struct definitions */\n'
350 yield str(msg) + '\n\n'
352 yield '/* Default values for struct fields */\n'
354 yield msg.default_decl(True)
357 yield '/* Struct field encoding specification for nanopb */\n'
359 yield msg.fields_declaration() + '\n'
363 def generate_source(headername, enums, messages):
364 '''Generate content for a source file.'''
366 yield '/* Automatically generated nanopb constant definitions */\n'
367 yield '#include "%s"\n\n' % headername
370 yield msg.default_decl(False)
375 yield msg.fields_definition() + '\n\n'
377 if __name__ == '__main__':
381 if len(sys.argv) != 2:
382 print "Usage: " + sys.argv[0] + " file.pb"
383 print "where file.pb has been compiled from .proto by:"
384 print "protoc -ofile.pb file.proto"
385 print "Output fill be written to file.pb.h and file.pb.c"
388 data = open(sys.argv[1]).read()
389 fdesc = descriptor.FileDescriptorSet.FromString(data)
390 enums, messages = parse_file(fdesc.file[0])
392 noext = os.path.splitext(sys.argv[1])[0]
393 headername = noext + '.pb.h'
394 sourcename = noext + '.pb.c'
395 headerbasename = os.path.basename(headername)
397 print "Writing to " + headername + " and " + sourcename
399 header = open(headername, 'w')
400 for part in generate_header(headerbasename, enums, messages):
403 source = open(sourcename, 'w')
404 for part in generate_source(headerbasename, enums, messages):