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_FIXED64'),
12 FieldD.TYPE_FIXED32: ('uint32_t', 'PB_LTYPE_FIXED32'),
13 FieldD.TYPE_FIXED64: ('uint64_t', 'PB_LTYPE_FIXED64'),
14 FieldD.TYPE_FLOAT: ('float', 'PB_LTYPE_FIXED32'),
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 if self.default is not None:
112 self.default = self.ctype + self.default
113 elif desc.type == FieldD.TYPE_STRING:
114 self.ltype = 'PB_LTYPE_STRING'
115 if self.max_size is None:
119 self.array_decl += '[%d]' % self.max_size
120 elif desc.type == FieldD.TYPE_BYTES:
121 self.ltype = 'PB_LTYPE_BYTES'
122 if self.max_size is None:
125 self.ctype = self.struct_name + self.name + 't'
126 elif desc.type == FieldD.TYPE_MESSAGE:
127 self.ltype = 'PB_LTYPE_SUBMESSAGE'
128 self.ctype = self.submsgname = names_from_type_name(desc.type_name)
130 raise NotImplementedError(desc.type)
133 self.htype = 'PB_HTYPE_CALLBACK'
134 self.ctype = 'pb_callback_t'
137 def __cmp__(self, other):
138 return cmp(self.tag, other.tag)
141 if self.htype == 'PB_HTYPE_OPTIONAL':
142 result = ' bool has_' + self.name + ';\n'
143 elif self.htype == 'PB_HTYPE_ARRAY':
144 result = ' size_t ' + self.name + '_count;\n'
147 result += ' %s %s%s;' % (self.ctype, self.name, self.array_decl)
151 '''Return definitions for any special types this field might need.'''
152 if self.ltype == 'PB_LTYPE_BYTES' and self.max_size is not None:
153 result = 'typedef struct {\n'
154 result += ' size_t size;\n'
155 result += ' uint8_t bytes[%d];\n' % self.max_size
156 result += '} %s;\n' % self.ctype
161 def default_decl(self, declaration_only = False):
162 '''Return definition for this field's default value.'''
163 if self.default is None:
166 if self.ltype == 'PB_LTYPE_STRING':
168 if self.max_size is None:
169 return None # Not implemented
171 array_decl = '[%d]' % (self.max_size + 1)
172 default = str(self.default).encode('string_escape')
173 default = default.replace('"', '\\"')
174 default = '"' + default + '"'
175 elif self.ltype == 'PB_LTYPE_BYTES':
176 data = self.default.decode('string_escape')
177 data = ['0x%02x' % ord(c) for c in data]
179 if self.max_size is None:
180 return None # Not implemented
184 default = '{%d, {%s}}' % (len(data), ','.join(data))
187 ctype, default = self.ctype, self.default
191 return 'extern const %s %s_default%s;' % (ctype, self.struct_name + self.name, array_decl)
193 return 'const %s %s_default%s = %s;' % (ctype, self.struct_name + self.name, array_decl, default)
195 def pb_field_t(self, prev_field_name):
196 '''Return the pb_field_t initializer to use in the constant array.
197 prev_field_name is the name of the previous field or None.
199 result = ' {%d, ' % self.tag
201 if self.ltype is not None:
202 result += ' | ' + self.ltype
205 if prev_field_name is None:
206 result += ' offsetof(%s, %s),' % (self.struct_name, self.name)
208 result += ' pb_delta_end(%s, %s, %s),' % (self.struct_name, self.name, prev_field_name)
210 if self.htype == 'PB_HTYPE_OPTIONAL':
211 result += '\n pb_delta(%s, has_%s, %s),' % (self.struct_name, self.name, self.name)
212 elif self.htype == 'PB_HTYPE_ARRAY':
213 result += '\n pb_delta(%s, %s_count, %s),' % (self.struct_name, self.name, self.name)
218 if self.htype == 'PB_HTYPE_ARRAY':
219 result += '\n pb_membersize(%s, %s[0]),' % (self.struct_name, self.name)
220 result += ('\n pb_membersize(%s, %s) / pb_membersize(%s, %s[0]),'
221 % (self.struct_name, self.name, self.struct_name, self.name))
222 elif self.htype != 'PB_HTYPE_CALLBACK' and self.ltype == 'PB_LTYPE_BYTES':
223 result += '\n pb_membersize(%s, bytes),' % self.ctype
226 result += '\n pb_membersize(%s, %s),' % (self.struct_name, self.name)
229 if self.ltype == 'PB_LTYPE_SUBMESSAGE':
230 result += '\n &%s_fields}' % self.submsgname
231 elif self.default is None or self.htype == 'PB_HTYPE_CALLBACK':
234 result += '\n &%s_default}' % (self.struct_name + self.name)
239 def __init__(self, names, desc):
241 self.fields = [Field(self.name, f) for f in desc.field]
242 self.ordered_fields = self.fields[:]
243 self.ordered_fields.sort()
245 def get_dependencies(self):
246 '''Get list of type names that this structure refers to.'''
247 return [str(field.ctype) for field in self.fields]
250 result = 'typedef struct {\n'
251 result += '\n'.join([str(f) for f in self.ordered_fields])
252 result += '\n} %s;' % self.name
257 for field in self.fields:
258 types = field.types()
259 if types is not None:
260 result += types + '\n'
263 def default_decl(self, declaration_only = False):
265 for field in self.fields:
266 default = field.default_decl(declaration_only)
267 if default is not None:
268 result += default + '\n'
271 def fields_declaration(self):
272 result = 'extern const pb_field_t %s_fields[%d];' % (self.name, len(self.fields) + 1)
275 def fields_definition(self):
276 result = 'const pb_field_t %s_fields[%d] = {\n' % (self.name, len(self.fields) + 1)
279 for field in self.ordered_fields:
280 result += field.pb_field_t(prev)
284 result += ' PB_LAST_FIELD\n};'
287 def iterate_messages(desc, names = Names()):
288 '''Recursively find all messages. For each, yield name, DescriptorProto.'''
289 if hasattr(desc, 'message_type'):
290 submsgs = desc.message_type
292 submsgs = desc.nested_type
294 for submsg in submsgs:
295 sub_names = names + submsg.name
296 yield sub_names, submsg
298 for x in iterate_messages(submsg, sub_names):
301 def parse_file(fdesc):
302 '''Takes a FileDescriptorProto and returns tuple (enum, messages).'''
308 base_name = Names(fdesc.package.split('.'))
312 for enum in fdesc.enum_type:
313 enums.append(Enum(base_name, enum))
315 for names, message in iterate_messages(fdesc, base_name):
316 messages.append(Message(names, message))
317 for enum in message.enum_type:
318 enums.append(Enum(names, enum))
320 return enums, messages
324 From http://code.activestate.com/recipes/577413-topological-sort/
325 This function is under the MIT license.
327 for k, v in data.items():
328 v.discard(k) # Ignore self dependencies
329 extra_items_in_deps = reduce(set.union, data.values()) - set(data.keys())
330 data.update(dict([(item, set()) for item in extra_items_in_deps]))
332 ordered = set(item for item,dep in data.items() if not dep)
335 for item in sorted(ordered):
337 data = dict([(item, (dep - ordered)) for item,dep in data.items()
338 if item not in ordered])
339 assert not data, "A cyclic dependency exists amongst %r" % data
341 def sort_dependencies(messages):
342 '''Sort a list of Messages based on dependencies.'''
345 for message in messages:
346 dependencies[str(message.name)] = set(message.get_dependencies())
347 message_by_name[str(message.name)] = message
349 for msgname in toposort2(dependencies):
350 if msgname in message_by_name:
351 yield message_by_name[msgname]
353 def generate_header(headername, enums, messages):
354 '''Generate content for a header file.
355 Generates strings, which should be concatenated and stored to file.
358 yield '/* Automatically generated nanopb header */\n'
360 symbol = headername.replace('.', '_').upper()
361 yield '#ifndef _PB_%s_\n' % symbol
362 yield '#define _PB_%s_\n' % symbol
363 yield '#include <pb.h>\n\n'
365 yield '/* Enum definitions */\n'
367 yield str(enum) + '\n\n'
369 yield '/* Struct definitions */\n'
370 for msg in sort_dependencies(messages):
372 yield str(msg) + '\n\n'
374 yield '/* Default values for struct fields */\n'
376 yield msg.default_decl(True)
379 yield '/* Struct field encoding specification for nanopb */\n'
381 yield msg.fields_declaration() + '\n'
385 def generate_source(headername, enums, messages):
386 '''Generate content for a source file.'''
388 yield '/* Automatically generated nanopb constant definitions */\n'
389 yield '#include "%s"\n\n' % headername
392 yield msg.default_decl(False)
397 yield msg.fields_definition() + '\n\n'
399 if __name__ == '__main__':
403 if len(sys.argv) != 2:
404 print "Usage: " + sys.argv[0] + " file.pb"
405 print "where file.pb has been compiled from .proto by:"
406 print "protoc -ofile.pb file.proto"
407 print "Output fill be written to file.pb.h and file.pb.c"
410 data = open(sys.argv[1]).read()
411 fdesc = descriptor.FileDescriptorSet.FromString(data)
412 enums, messages = parse_file(fdesc.file[0])
414 noext = os.path.splitext(sys.argv[1])[0]
415 headername = noext + '.pb.h'
416 sourcename = noext + '.pb.c'
417 headerbasename = os.path.basename(headername)
419 print "Writing to " + headername + " and " + sourcename
421 header = open(headername, 'w')
422 for part in generate_header(headerbasename, enums, messages):
425 source = open(sourcename, 'w')
426 for part in generate_source(headerbasename, enums, messages):