1 '''Generate header file for nanopb from a ProtoBuf FileDescriptorSet.'''
2 nanopb_version = "nanopb-0.1.7"
5 import google.protobuf.descriptor_pb2 as descriptor
8 print "*************************************************************"
9 print "*** Could not import the Google protobuf Python libraries ***"
10 print "*** Try installing package 'python-protobuf' or similar. ***"
11 print "*************************************************************"
19 print "***************************************************************"
20 print "*** Could not import the precompiled nanopb_pb2.py. ***"
21 print "*** Run 'make' in the 'generator' folder to update the file.***"
22 print "***************************************************************"
31 # ---------------------------------------------------------------------------
32 # Generation of single fields
33 # ---------------------------------------------------------------------------
38 # Values are tuple (c type, pb ltype)
39 FieldD = descriptor.FieldDescriptorProto
41 FieldD.TYPE_BOOL: ('bool', 'PB_LTYPE_VARINT'),
42 FieldD.TYPE_DOUBLE: ('double', 'PB_LTYPE_FIXED64'),
43 FieldD.TYPE_FIXED32: ('uint32_t', 'PB_LTYPE_FIXED32'),
44 FieldD.TYPE_FIXED64: ('uint64_t', 'PB_LTYPE_FIXED64'),
45 FieldD.TYPE_FLOAT: ('float', 'PB_LTYPE_FIXED32'),
46 FieldD.TYPE_INT32: ('int32_t', 'PB_LTYPE_VARINT'),
47 FieldD.TYPE_INT64: ('int64_t', 'PB_LTYPE_VARINT'),
48 FieldD.TYPE_SFIXED32: ('int32_t', 'PB_LTYPE_FIXED32'),
49 FieldD.TYPE_SFIXED64: ('int64_t', 'PB_LTYPE_FIXED64'),
50 FieldD.TYPE_SINT32: ('int32_t', 'PB_LTYPE_SVARINT'),
51 FieldD.TYPE_SINT64: ('int64_t', 'PB_LTYPE_SVARINT'),
52 FieldD.TYPE_UINT32: ('uint32_t', 'PB_LTYPE_VARINT'),
53 FieldD.TYPE_UINT64: ('uint64_t', 'PB_LTYPE_VARINT')
57 '''Keeps a set of nested names and formats them to C identifier.
58 You can subclass this with your own implementation.
60 def __init__(self, parts = ()):
61 if isinstance(parts, Names):
63 self.parts = tuple(parts)
66 return '_'.join(self.parts)
68 def __add__(self, other):
69 if isinstance(other, (str, unicode)):
70 return Names(self.parts + (other,))
71 elif isinstance(other, tuple):
72 return Names(self.parts + other)
74 raise ValueError("Name parts should be of type str")
76 def names_from_type_name(type_name):
77 '''Parse Names() from FieldDescriptorProto type_name'''
78 if type_name[0] != '.':
79 raise NotImplementedError("Lookup of non-absolute type names is not supported")
80 return Names(type_name[1:].split('.'))
83 def __init__(self, names, desc, enum_options):
84 '''desc is EnumDescriptorProto'''
86 if enum_options.long_names:
87 self.names = names + desc.name
91 self.values = [(self.names + x.name, x.number) for x in desc.value]
94 result = 'typedef enum _%s {\n' % self.names
95 result += ',\n'.join([" %s = %d" % x for x in self.values])
96 result += '\n} %s;' % self.names
100 def __init__(self, struct_name, desc, field_options):
101 '''desc is FieldDescriptorProto'''
102 self.tag = desc.number
103 self.struct_name = struct_name
104 self.name = desc.name
107 self.max_count = None
110 # Parse field options
111 if field_options.HasField("max_size"):
112 self.max_size = field_options.max_size
114 if field_options.HasField("max_count"):
115 self.max_count = field_options.max_count
117 if desc.HasField('default_value'):
118 self.default = desc.default_value
121 # HTYPE is the high-order nibble of nanopb field description,
122 # defining whether value is required/optional/repeated.
124 if desc.label == FieldD.LABEL_REQUIRED:
125 self.htype = 'PB_HTYPE_REQUIRED'
126 elif desc.label == FieldD.LABEL_OPTIONAL:
127 self.htype = 'PB_HTYPE_OPTIONAL'
128 elif desc.label == FieldD.LABEL_REPEATED:
129 if self.max_count is None:
130 can_be_static = False
132 self.htype = 'PB_HTYPE_ARRAY'
133 self.array_decl = '[%d]' % self.max_count
135 raise NotImplementedError(desc.label)
137 # Decide LTYPE and CTYPE
138 # LTYPE is the low-order nibble of nanopb field description,
139 # defining how to decode an individual value.
140 # CTYPE is the name of the c type to use in the struct.
141 if datatypes.has_key(desc.type):
142 self.ctype, self.ltype = datatypes[desc.type]
143 elif desc.type == FieldD.TYPE_ENUM:
144 self.ltype = 'PB_LTYPE_VARINT'
145 self.ctype = names_from_type_name(desc.type_name)
146 if self.default is not None:
147 self.default = self.ctype + self.default
148 elif desc.type == FieldD.TYPE_STRING:
149 self.ltype = 'PB_LTYPE_STRING'
150 if self.max_size is None:
151 can_be_static = False
154 self.array_decl += '[%d]' % self.max_size
155 elif desc.type == FieldD.TYPE_BYTES:
156 self.ltype = 'PB_LTYPE_BYTES'
157 if self.max_size is None:
158 can_be_static = False
160 self.ctype = self.struct_name + self.name + 't'
161 elif desc.type == FieldD.TYPE_MESSAGE:
162 self.ltype = 'PB_LTYPE_SUBMESSAGE'
163 self.ctype = self.submsgname = names_from_type_name(desc.type_name)
165 raise NotImplementedError(desc.type)
167 if field_options.type == nanopb_pb2.FT_DEFAULT:
169 field_options.type = nanopb_pb2.FT_STATIC
171 field_options.type = nanopb_pb2.FT_CALLBACK
173 if field_options.type == nanopb_pb2.FT_STATIC and not can_be_static:
174 raise Exception("Field %s is defined as static, but max_size or max_count is not given." % self.name)
176 if field_options.type == nanopb_pb2.FT_CALLBACK:
177 self.htype = 'PB_HTYPE_CALLBACK'
178 self.ctype = 'pb_callback_t'
181 def __cmp__(self, other):
182 return cmp(self.tag, other.tag)
185 if self.htype == 'PB_HTYPE_OPTIONAL':
186 result = ' bool has_' + self.name + ';\n'
187 elif self.htype == 'PB_HTYPE_ARRAY':
188 result = ' size_t ' + self.name + '_count;\n'
191 result += ' %s %s%s;' % (self.ctype, self.name, self.array_decl)
195 '''Return definitions for any special types this field might need.'''
196 if self.ltype == 'PB_LTYPE_BYTES' and self.max_size is not None:
197 result = 'typedef struct {\n'
198 result += ' size_t size;\n'
199 result += ' uint8_t bytes[%d];\n' % self.max_size
200 result += '} %s;\n' % self.ctype
205 def default_decl(self, declaration_only = False):
206 '''Return definition for this field's default value.'''
207 if self.default is None:
210 if self.ltype == 'PB_LTYPE_STRING':
212 if self.max_size is None:
213 return None # Not implemented
215 array_decl = '[%d]' % (self.max_size + 1)
216 default = str(self.default).encode('string_escape')
217 default = default.replace('"', '\\"')
218 default = '"' + default + '"'
219 elif self.ltype == 'PB_LTYPE_BYTES':
220 data = self.default.decode('string_escape')
221 data = ['0x%02x' % ord(c) for c in data]
223 if self.max_size is None:
224 return None # Not implemented
228 default = '{%d, {%s}}' % (len(data), ','.join(data))
231 ctype, default = self.ctype, self.default
235 return 'extern const %s %s_default%s;' % (ctype, self.struct_name + self.name, array_decl)
237 return 'const %s %s_default%s = %s;' % (ctype, self.struct_name + self.name, array_decl, default)
239 def pb_field_t(self, prev_field_name):
240 '''Return the pb_field_t initializer to use in the constant array.
241 prev_field_name is the name of the previous field or None.
243 result = ' {%d, ' % self.tag
244 result += '(pb_type_t) ((int) ' + self.htype
245 if self.ltype is not None:
246 result += ' | (int) ' + self.ltype
249 if prev_field_name is None:
250 result += ' offsetof(%s, %s),' % (self.struct_name, self.name)
252 result += ' pb_delta_end(%s, %s, %s),' % (self.struct_name, self.name, prev_field_name)
254 if self.htype == 'PB_HTYPE_OPTIONAL':
255 result += '\n pb_delta(%s, has_%s, %s),' % (self.struct_name, self.name, self.name)
256 elif self.htype == 'PB_HTYPE_ARRAY':
257 result += '\n pb_delta(%s, %s_count, %s),' % (self.struct_name, self.name, self.name)
262 if self.htype == 'PB_HTYPE_ARRAY':
263 result += '\n pb_membersize(%s, %s[0]),' % (self.struct_name, self.name)
264 result += ('\n pb_membersize(%s, %s) / pb_membersize(%s, %s[0]),'
265 % (self.struct_name, self.name, self.struct_name, self.name))
267 result += '\n pb_membersize(%s, %s),' % (self.struct_name, self.name)
270 if self.ltype == 'PB_LTYPE_SUBMESSAGE':
271 result += '\n &%s_fields}' % self.submsgname
272 elif self.default is None or self.htype == 'PB_HTYPE_CALLBACK':
275 result += '\n &%s_default}' % (self.struct_name + self.name)
279 def largest_field_value(self):
280 '''Determine if this field needs 16bit or 32bit pb_field_t structure to compile properly.
281 Returns numeric value or a C-expression for assert.'''
282 if self.ltype == 'PB_LTYPE_SUBMESSAGE':
283 if self.htype == 'PB_HTYPE_ARRAY':
284 return 'pb_membersize(%s, %s[0])' % (self.struct_name, self.name)
286 return 'pb_membersize(%s, %s)' % (self.struct_name, self.name)
288 return max(self.tag, self.max_size, self.max_count)
295 # ---------------------------------------------------------------------------
296 # Generation of messages (structures)
297 # ---------------------------------------------------------------------------
301 def __init__(self, names, desc, message_options):
303 self.fields = [Field(self.name, f, get_nanopb_suboptions(f, message_options)) for f in desc.field]
304 self.ordered_fields = self.fields[:]
305 self.ordered_fields.sort()
307 def get_dependencies(self):
308 '''Get list of type names that this structure refers to.'''
309 return [str(field.ctype) for field in self.fields]
312 result = 'typedef struct _%s {\n' % self.name
313 result += '\n'.join([str(f) for f in self.ordered_fields])
314 result += '\n} %s;' % self.name
319 for field in self.fields:
320 types = field.types()
321 if types is not None:
322 result += types + '\n'
325 def default_decl(self, declaration_only = False):
327 for field in self.fields:
328 default = field.default_decl(declaration_only)
329 if default is not None:
330 result += default + '\n'
333 def fields_declaration(self):
334 result = 'extern const pb_field_t %s_fields[%d];' % (self.name, len(self.fields) + 1)
337 def fields_definition(self):
338 result = 'const pb_field_t %s_fields[%d] = {\n' % (self.name, len(self.fields) + 1)
341 for field in self.ordered_fields:
342 result += field.pb_field_t(prev)
346 result += ' PB_LAST_FIELD\n};'
354 # ---------------------------------------------------------------------------
355 # Processing of entire .proto files
356 # ---------------------------------------------------------------------------
359 def iterate_messages(desc, names = Names()):
360 '''Recursively find all messages. For each, yield name, DescriptorProto.'''
361 if hasattr(desc, 'message_type'):
362 submsgs = desc.message_type
364 submsgs = desc.nested_type
366 for submsg in submsgs:
367 sub_names = names + submsg.name
368 yield sub_names, submsg
370 for x in iterate_messages(submsg, sub_names):
373 def parse_file(fdesc, file_options):
374 '''Takes a FileDescriptorProto and returns tuple (enum, messages).'''
380 base_name = Names(fdesc.package.split('.'))
384 for enum in fdesc.enum_type:
385 enum_options = get_nanopb_suboptions(enum, file_options)
386 enums.append(Enum(base_name, enum, enum_options))
388 for names, message in iterate_messages(fdesc, base_name):
389 message_options = get_nanopb_suboptions(message, file_options)
390 messages.append(Message(names, message, message_options))
391 for enum in message.enum_type:
392 enums.append(Enum(names, enum, message_options))
394 return enums, messages
398 From http://code.activestate.com/recipes/577413-topological-sort/
399 This function is under the MIT license.
401 for k, v in data.items():
402 v.discard(k) # Ignore self dependencies
403 extra_items_in_deps = reduce(set.union, data.values(), set()) - set(data.keys())
404 data.update(dict([(item, set()) for item in extra_items_in_deps]))
406 ordered = set(item for item,dep in data.items() if not dep)
409 for item in sorted(ordered):
411 data = dict([(item, (dep - ordered)) for item,dep in data.items()
412 if item not in ordered])
413 assert not data, "A cyclic dependency exists amongst %r" % data
415 def sort_dependencies(messages):
416 '''Sort a list of Messages based on dependencies.'''
419 for message in messages:
420 dependencies[str(message.name)] = set(message.get_dependencies())
421 message_by_name[str(message.name)] = message
423 for msgname in toposort2(dependencies):
424 if msgname in message_by_name:
425 yield message_by_name[msgname]
427 def generate_header(dependencies, headername, enums, messages):
428 '''Generate content for a header file.
429 Generates strings, which should be concatenated and stored to file.
432 yield '/* Automatically generated nanopb header */\n'
433 yield '/* Generated by %s at %s. */\n\n' % (nanopb_version, time.asctime())
435 symbol = headername.replace('.', '_').upper()
436 yield '#ifndef _PB_%s_\n' % symbol
437 yield '#define _PB_%s_\n' % symbol
438 yield '#include <pb.h>\n\n'
440 for dependency in dependencies:
441 noext = os.path.splitext(dependency)[0]
442 yield '#include "%s.pb.h"\n' % noext
444 yield '#ifdef __cplusplus\n'
445 yield 'extern "C" {\n'
448 yield '/* Enum definitions */\n'
450 yield str(enum) + '\n\n'
452 yield '/* Struct definitions */\n'
453 for msg in sort_dependencies(messages):
455 yield str(msg) + '\n\n'
457 yield '/* Default values for struct fields */\n'
459 yield msg.default_decl(True)
462 yield '/* Struct field encoding specification for nanopb */\n'
464 yield msg.fields_declaration() + '\n'
467 count_required_fields = lambda m: len([f for f in msg.fields if f.htype == 'PB_HTYPE_REQUIRED'])
468 largest_msg = max(messages, key = count_required_fields)
469 largest_count = count_required_fields(largest_msg)
470 if largest_count > 64:
471 yield '\n/* Check that missing required fields will be properly detected */\n'
472 yield '#if PB_MAX_REQUIRED_FIELDS < %d\n' % largest_count
473 yield '#error Properly detecting missing required fields in %s requires \\\n' % largest_msg.name
474 yield ' setting PB_MAX_REQUIRED_FIELDS to %d or more.\n' % largest_count
481 for field in msg.fields:
482 status = field.largest_field_value()
483 if isinstance(status, (str, unicode)):
484 checks.append(status)
487 worst_field = str(field.struct_name) + '.' + str(field.name)
489 if worst > 255 or checks:
490 yield '\n/* Check that field information fits in pb_field_t */\n'
493 yield '#if !defined(PB_FIELD_16BIT) && !defined(PB_FIELD_32BIT)\n'
495 yield '#error Field descriptor for %s is too large. Define PB_FIELD_16BIT to fix this.\n' % worst_field
497 assertion = ' && '.join(str(c) + ' < 256' for c in checks)
498 yield 'STATIC_ASSERT((%s), YOU_MUST_DEFINE_PB_FIELD_16BIT)\n' % assertion
501 if worst > 65535 or checks:
502 yield '#if !defined(PB_FIELD_32BIT)\n'
504 yield '#error Field descriptor for %s is too large. Define PB_FIELD_32BIT to fix this.\n' % worst_field
506 assertion = ' && '.join(str(c) + ' < 65536' for c in checks)
507 yield 'STATIC_ASSERT((%s), YOU_MUST_DEFINE_PB_FIELD_32BIT)\n' % assertion
510 yield '\n#ifdef __cplusplus\n'
511 yield '} /* extern "C" */\n'
517 def generate_source(headername, enums, messages):
518 '''Generate content for a source file.'''
520 yield '/* Automatically generated nanopb constant definitions */\n'
521 yield '/* Generated by %s at %s. */\n\n' % (nanopb_version, time.asctime())
522 yield '#include "%s"\n\n' % headername
525 yield msg.default_decl(False)
530 yield msg.fields_definition() + '\n\n'
534 # ---------------------------------------------------------------------------
535 # Command line interface
536 # ---------------------------------------------------------------------------
540 from optparse import OptionParser
541 import google.protobuf.text_format as text_format
543 optparser = OptionParser(
544 usage = "Usage: nanopb_generator.py [options] file.pb ...",
545 epilog = "Compile file.pb from file.proto by: 'protoc -ofile.pb file.proto'. " +
546 "Output will be written to file.pb.h and file.pb.c.")
547 optparser.add_option("-x", dest="exclude", metavar="FILE", action="append", default=[],
548 help="Exclude file from generated #include list.")
549 optparser.add_option("-q", "--quiet", dest="quiet", action="store_true", default=False,
550 help="Don't print anything except errors.")
551 optparser.add_option("-v", "--verbose", dest="verbose", action="store_true", default=False,
552 help="Print more information.")
553 optparser.add_option("-s", dest="settings", metavar="OPTION:VALUE", action="append", default=[],
554 help="Set generator option (max_size, max_count etc.).")
556 def get_nanopb_suboptions(subdesc, options):
557 '''Get copy of options, and merge information from subdesc.'''
558 new_options = nanopb_pb2.NanoPBOptions()
559 new_options.CopyFrom(options)
561 if isinstance(subdesc.options, descriptor.FieldOptions):
562 ext_type = nanopb_pb2.nanopb
563 elif isinstance(subdesc.options, descriptor.FileOptions):
564 ext_type = nanopb_pb2.nanopb_fileopt
565 elif isinstance(subdesc.options, descriptor.MessageOptions):
566 ext_type = nanopb_pb2.nanopb_msgopt
567 elif isinstance(subdesc.options, descriptor.EnumOptions):
568 ext_type = nanopb_pb2.nanopb_enumopt
570 raise Exception("Unknown options type")
572 if subdesc.options.HasExtension(ext_type):
573 ext = subdesc.options.Extensions[ext_type]
574 new_options.MergeFrom(ext)
578 def process(filenames, options):
579 '''Process the files given on the command line.'''
582 optparser.print_help()
586 options.verbose = False
588 toplevel_options = nanopb_pb2.NanoPBOptions()
589 for s in options.settings:
590 text_format.Merge(s, toplevel_options)
592 for filename in filenames:
593 data = open(filename, 'rb').read()
594 fdesc = descriptor.FileDescriptorSet.FromString(data)
596 file_options = get_nanopb_suboptions(fdesc.file[0], toplevel_options)
599 print "Options for " + filename + ":"
600 print text_format.MessageToString(file_options)
602 enums, messages = parse_file(fdesc.file[0], file_options)
604 noext = os.path.splitext(filename)[0]
605 headername = noext + '.pb.h'
606 sourcename = noext + '.pb.c'
607 headerbasename = os.path.basename(headername)
609 if not options.quiet:
610 print "Writing to " + headername + " and " + sourcename
612 # List of .proto files that should not be included in the C header file
613 # even if they are mentioned in the source .proto.
614 excludes = ['nanopb.proto', 'google/protobuf/descriptor.proto'] + options.exclude
615 dependencies = [d for d in fdesc.file[0].dependency if d not in excludes]
617 header = open(headername, 'w')
618 for part in generate_header(dependencies, headerbasename, enums, messages):
621 source = open(sourcename, 'w')
622 for part in generate_source(headerbasename, enums, messages):
627 if __name__ == '__main__':
628 options, filenames = optparser.parse_args()
629 status = process(filenames, options)