1 '''Generate header file for nanopb from a ProtoBuf FileDescriptorSet.'''
2 nanopb_version = "nanopb-0.1.8"
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 __eq__(self, other):
77 return isinstance(other, Names) and self.parts == other.parts
79 def names_from_type_name(type_name):
80 '''Parse Names() from FieldDescriptorProto type_name'''
81 if type_name[0] != '.':
82 raise NotImplementedError("Lookup of non-absolute type names is not supported")
83 return Names(type_name[1:].split('.'))
86 def __init__(self, names, desc, enum_options):
87 '''desc is EnumDescriptorProto'''
89 self.options = enum_options
90 self.names = names + desc.name
92 if enum_options.long_names:
93 self.values = [(self.names + x.name, x.number) for x in desc.value]
95 self.values = [(names + x.name, x.number) for x in desc.value]
97 self.value_longnames = [self.names + x.name for x in desc.value]
100 result = 'typedef enum _%s {\n' % self.names
101 result += ',\n'.join([" %s = %d" % x for x in self.values])
102 result += '\n} %s;' % self.names
106 def __init__(self, struct_name, desc, field_options):
107 '''desc is FieldDescriptorProto'''
108 self.tag = desc.number
109 self.struct_name = struct_name
110 self.name = desc.name
113 self.max_count = None
116 # Parse field options
117 if field_options.HasField("max_size"):
118 self.max_size = field_options.max_size
120 if field_options.HasField("max_count"):
121 self.max_count = field_options.max_count
123 if desc.HasField('default_value'):
124 self.default = desc.default_value
127 # HTYPE is the high-order nibble of nanopb field description,
128 # defining whether value is required/optional/repeated.
130 if desc.label == FieldD.LABEL_REQUIRED:
131 self.htype = 'PB_HTYPE_REQUIRED'
132 elif desc.label == FieldD.LABEL_OPTIONAL:
133 self.htype = 'PB_HTYPE_OPTIONAL'
134 elif desc.label == FieldD.LABEL_REPEATED:
135 if self.max_count is None:
136 can_be_static = False
138 self.htype = 'PB_HTYPE_ARRAY'
139 self.array_decl = '[%d]' % self.max_count
141 raise NotImplementedError(desc.label)
143 # Decide LTYPE and CTYPE
144 # LTYPE is the low-order nibble of nanopb field description,
145 # defining how to decode an individual value.
146 # CTYPE is the name of the c type to use in the struct.
147 if datatypes.has_key(desc.type):
148 self.ctype, self.ltype = datatypes[desc.type]
149 elif desc.type == FieldD.TYPE_ENUM:
150 self.ltype = 'PB_LTYPE_VARINT'
151 self.ctype = names_from_type_name(desc.type_name)
152 if self.default is not None:
153 self.default = self.ctype + self.default
154 elif desc.type == FieldD.TYPE_STRING:
155 self.ltype = 'PB_LTYPE_STRING'
156 if self.max_size is None:
157 can_be_static = False
160 self.array_decl += '[%d]' % self.max_size
161 elif desc.type == FieldD.TYPE_BYTES:
162 self.ltype = 'PB_LTYPE_BYTES'
163 if self.max_size is None:
164 can_be_static = False
166 self.ctype = self.struct_name + self.name + 't'
167 elif desc.type == FieldD.TYPE_MESSAGE:
168 self.ltype = 'PB_LTYPE_SUBMESSAGE'
169 self.ctype = self.submsgname = names_from_type_name(desc.type_name)
171 raise NotImplementedError(desc.type)
173 if field_options.type == nanopb_pb2.FT_DEFAULT:
175 field_options.type = nanopb_pb2.FT_STATIC
177 field_options.type = nanopb_pb2.FT_CALLBACK
179 if field_options.type == nanopb_pb2.FT_STATIC and not can_be_static:
180 raise Exception("Field %s is defined as static, but max_size or max_count is not given." % self.name)
182 if field_options.type == nanopb_pb2.FT_CALLBACK:
183 self.htype = 'PB_HTYPE_CALLBACK'
184 self.ctype = 'pb_callback_t'
187 def __cmp__(self, other):
188 return cmp(self.tag, other.tag)
191 if self.htype == 'PB_HTYPE_OPTIONAL':
192 result = ' bool has_' + self.name + ';\n'
193 elif self.htype == 'PB_HTYPE_ARRAY':
194 result = ' size_t ' + self.name + '_count;\n'
197 result += ' %s %s%s;' % (self.ctype, self.name, self.array_decl)
201 '''Return definitions for any special types this field might need.'''
202 if self.ltype == 'PB_LTYPE_BYTES' and self.max_size is not None:
203 result = 'typedef struct {\n'
204 result += ' size_t size;\n'
205 result += ' uint8_t bytes[%d];\n' % self.max_size
206 result += '} %s;\n' % self.ctype
211 def default_decl(self, declaration_only = False):
212 '''Return definition for this field's default value.'''
213 if self.default is None:
216 if self.ltype == 'PB_LTYPE_STRING':
218 if self.max_size is None:
219 return None # Not implemented
221 array_decl = '[%d]' % (self.max_size + 1)
222 default = str(self.default).encode('string_escape')
223 default = default.replace('"', '\\"')
224 default = '"' + default + '"'
225 elif self.ltype == 'PB_LTYPE_BYTES':
226 data = self.default.decode('string_escape')
227 data = ['0x%02x' % ord(c) for c in data]
229 if self.max_size is None:
230 return None # Not implemented
234 default = '{%d, {%s}}' % (len(data), ','.join(data))
237 ctype, default = self.ctype, self.default
241 return 'extern const %s %s_default%s;' % (ctype, self.struct_name + self.name, array_decl)
243 return 'const %s %s_default%s = %s;' % (ctype, self.struct_name + self.name, array_decl, default)
245 def pb_field_t(self, prev_field_name):
246 '''Return the pb_field_t initializer to use in the constant array.
247 prev_field_name is the name of the previous field or None.
249 result = ' {%d, ' % self.tag
250 result += '(pb_type_t) ((int) ' + self.htype
251 if self.ltype is not None:
252 result += ' | (int) ' + self.ltype
255 if prev_field_name is None:
256 result += ' offsetof(%s, %s),' % (self.struct_name, self.name)
258 result += ' pb_delta_end(%s, %s, %s),' % (self.struct_name, self.name, prev_field_name)
260 if self.htype == 'PB_HTYPE_OPTIONAL':
261 result += '\n pb_delta(%s, has_%s, %s),' % (self.struct_name, self.name, self.name)
262 elif self.htype == 'PB_HTYPE_ARRAY':
263 result += '\n pb_delta(%s, %s_count, %s),' % (self.struct_name, self.name, self.name)
268 if self.htype == 'PB_HTYPE_ARRAY':
269 result += '\n pb_membersize(%s, %s[0]),' % (self.struct_name, self.name)
270 result += ('\n pb_membersize(%s, %s) / pb_membersize(%s, %s[0]),'
271 % (self.struct_name, self.name, self.struct_name, self.name))
273 result += '\n pb_membersize(%s, %s),' % (self.struct_name, self.name)
276 if self.ltype == 'PB_LTYPE_SUBMESSAGE':
277 result += '\n &%s_fields}' % self.submsgname
278 elif self.default is None or self.htype == 'PB_HTYPE_CALLBACK':
281 result += '\n &%s_default}' % (self.struct_name + self.name)
285 def largest_field_value(self):
286 '''Determine if this field needs 16bit or 32bit pb_field_t structure to compile properly.
287 Returns numeric value or a C-expression for assert.'''
288 if self.ltype == 'PB_LTYPE_SUBMESSAGE':
289 if self.htype == 'PB_HTYPE_ARRAY':
290 return 'pb_membersize(%s, %s[0])' % (self.struct_name, self.name)
292 return 'pb_membersize(%s, %s)' % (self.struct_name, self.name)
294 return max(self.tag, self.max_size, self.max_count)
301 # ---------------------------------------------------------------------------
302 # Generation of messages (structures)
303 # ---------------------------------------------------------------------------
307 def __init__(self, names, desc, message_options):
309 self.fields = [Field(self.name, f, get_nanopb_suboptions(f, message_options)) for f in desc.field]
310 self.ordered_fields = self.fields[:]
311 self.ordered_fields.sort()
313 def get_dependencies(self):
314 '''Get list of type names that this structure refers to.'''
315 return [str(field.ctype) for field in self.fields]
318 result = 'typedef struct _%s {\n' % self.name
319 result += '\n'.join([str(f) for f in self.ordered_fields])
320 result += '\n} %s;' % self.name
325 for field in self.fields:
326 types = field.types()
327 if types is not None:
328 result += types + '\n'
331 def default_decl(self, declaration_only = False):
333 for field in self.fields:
334 default = field.default_decl(declaration_only)
335 if default is not None:
336 result += default + '\n'
339 def fields_declaration(self):
340 result = 'extern const pb_field_t %s_fields[%d];' % (self.name, len(self.fields) + 1)
343 def fields_definition(self):
344 result = 'const pb_field_t %s_fields[%d] = {\n' % (self.name, len(self.fields) + 1)
347 for field in self.ordered_fields:
348 result += field.pb_field_t(prev)
352 result += ' PB_LAST_FIELD\n};'
360 # ---------------------------------------------------------------------------
361 # Processing of entire .proto files
362 # ---------------------------------------------------------------------------
365 def iterate_messages(desc, names = Names()):
366 '''Recursively find all messages. For each, yield name, DescriptorProto.'''
367 if hasattr(desc, 'message_type'):
368 submsgs = desc.message_type
370 submsgs = desc.nested_type
372 for submsg in submsgs:
373 sub_names = names + submsg.name
374 yield sub_names, submsg
376 for x in iterate_messages(submsg, sub_names):
379 def parse_file(fdesc, file_options):
380 '''Takes a FileDescriptorProto and returns tuple (enum, messages).'''
386 base_name = Names(fdesc.package.split('.'))
390 for enum in fdesc.enum_type:
391 enum_options = get_nanopb_suboptions(enum, file_options)
392 enums.append(Enum(base_name, enum, enum_options))
394 for names, message in iterate_messages(fdesc, base_name):
395 message_options = get_nanopb_suboptions(message, file_options)
396 messages.append(Message(names, message, message_options))
397 for enum in message.enum_type:
398 enum_options = get_nanopb_suboptions(enum, message_options)
399 enums.append(Enum(names, enum, enum_options))
401 # Fix field default values where enum short names are used.
403 if not enum.options.long_names:
404 for message in messages:
405 for field in message.fields:
406 if field.default in enum.value_longnames:
407 idx = enum.value_longnames.index(field.default)
408 field.default = enum.values[idx][0]
410 return enums, messages
414 From http://code.activestate.com/recipes/577413-topological-sort/
415 This function is under the MIT license.
417 for k, v in data.items():
418 v.discard(k) # Ignore self dependencies
419 extra_items_in_deps = reduce(set.union, data.values(), set()) - set(data.keys())
420 data.update(dict([(item, set()) for item in extra_items_in_deps]))
422 ordered = set(item for item,dep in data.items() if not dep)
425 for item in sorted(ordered):
427 data = dict([(item, (dep - ordered)) for item,dep in data.items()
428 if item not in ordered])
429 assert not data, "A cyclic dependency exists amongst %r" % data
431 def sort_dependencies(messages):
432 '''Sort a list of Messages based on dependencies.'''
435 for message in messages:
436 dependencies[str(message.name)] = set(message.get_dependencies())
437 message_by_name[str(message.name)] = message
439 for msgname in toposort2(dependencies):
440 if msgname in message_by_name:
441 yield message_by_name[msgname]
443 def generate_header(dependencies, headername, enums, messages):
444 '''Generate content for a header file.
445 Generates strings, which should be concatenated and stored to file.
448 yield '/* Automatically generated nanopb header */\n'
449 yield '/* Generated by %s at %s. */\n\n' % (nanopb_version, time.asctime())
451 symbol = headername.replace('.', '_').upper()
452 yield '#ifndef _PB_%s_\n' % symbol
453 yield '#define _PB_%s_\n' % symbol
454 yield '#include <pb.h>\n\n'
456 for dependency in dependencies:
457 noext = os.path.splitext(dependency)[0]
458 yield '#include "%s.pb.h"\n' % noext
460 yield '#ifdef __cplusplus\n'
461 yield 'extern "C" {\n'
464 yield '/* Enum definitions */\n'
466 yield str(enum) + '\n\n'
468 yield '/* Struct definitions */\n'
469 for msg in sort_dependencies(messages):
471 yield str(msg) + '\n\n'
473 yield '/* Default values for struct fields */\n'
475 yield msg.default_decl(True)
478 yield '/* Struct field encoding specification for nanopb */\n'
480 yield msg.fields_declaration() + '\n'
483 count_required_fields = lambda m: len([f for f in msg.fields if f.htype == 'PB_HTYPE_REQUIRED'])
484 largest_msg = max(messages, key = count_required_fields)
485 largest_count = count_required_fields(largest_msg)
486 if largest_count > 64:
487 yield '\n/* Check that missing required fields will be properly detected */\n'
488 yield '#if PB_MAX_REQUIRED_FIELDS < %d\n' % largest_count
489 yield '#error Properly detecting missing required fields in %s requires \\\n' % largest_msg.name
490 yield ' setting PB_MAX_REQUIRED_FIELDS to %d or more.\n' % largest_count
498 checks_msgnames.append(msg.name)
499 for field in msg.fields:
500 status = field.largest_field_value()
501 if isinstance(status, (str, unicode)):
502 checks.append(status)
505 worst_field = str(field.struct_name) + '.' + str(field.name)
507 if worst > 255 or checks:
508 yield '\n/* Check that field information fits in pb_field_t */\n'
511 yield '#if !defined(PB_FIELD_16BIT) && !defined(PB_FIELD_32BIT)\n'
513 yield '#error Field descriptor for %s is too large. Define PB_FIELD_16BIT to fix this.\n' % worst_field
515 assertion = ' && '.join(str(c) + ' < 256' for c in checks)
516 msgs = '_'.join(str(n) for n in checks_msgnames)
517 yield 'STATIC_ASSERT((%s), YOU_MUST_DEFINE_PB_FIELD_16BIT_FOR_MESSAGES_%s)\n'%(assertion,msgs)
520 if worst > 65535 or checks:
521 yield '#if !defined(PB_FIELD_32BIT)\n'
523 yield '#error Field descriptor for %s is too large. Define PB_FIELD_32BIT to fix this.\n' % worst_field
525 assertion = ' && '.join(str(c) + ' < 65536' for c in checks)
526 msgs = '_'.join(str(n) for n in checks_msgnames)
527 yield 'STATIC_ASSERT((%s), YOU_MUST_DEFINE_PB_FIELD_32BIT_FOR_MESSAGES_%s)\n'%(assertion,msgs)
530 yield '\n#ifdef __cplusplus\n'
531 yield '} /* extern "C" */\n'
537 def generate_source(headername, enums, messages):
538 '''Generate content for a source file.'''
540 yield '/* Automatically generated nanopb constant definitions */\n'
541 yield '/* Generated by %s at %s. */\n\n' % (nanopb_version, time.asctime())
542 yield '#include "%s"\n\n' % headername
545 yield msg.default_decl(False)
550 yield msg.fields_definition() + '\n\n'
554 # ---------------------------------------------------------------------------
555 # Command line interface
556 # ---------------------------------------------------------------------------
560 from optparse import OptionParser
561 import google.protobuf.text_format as text_format
563 optparser = OptionParser(
564 usage = "Usage: nanopb_generator.py [options] file.pb ...",
565 epilog = "Compile file.pb from file.proto by: 'protoc -ofile.pb file.proto'. " +
566 "Output will be written to file.pb.h and file.pb.c.")
567 optparser.add_option("-x", dest="exclude", metavar="FILE", action="append", default=[],
568 help="Exclude file from generated #include list.")
569 optparser.add_option("-q", "--quiet", dest="quiet", action="store_true", default=False,
570 help="Don't print anything except errors.")
571 optparser.add_option("-v", "--verbose", dest="verbose", action="store_true", default=False,
572 help="Print more information.")
573 optparser.add_option("-s", dest="settings", metavar="OPTION:VALUE", action="append", default=[],
574 help="Set generator option (max_size, max_count etc.).")
576 def get_nanopb_suboptions(subdesc, options):
577 '''Get copy of options, and merge information from subdesc.'''
578 new_options = nanopb_pb2.NanoPBOptions()
579 new_options.CopyFrom(options)
581 if isinstance(subdesc.options, descriptor.FieldOptions):
582 ext_type = nanopb_pb2.nanopb
583 elif isinstance(subdesc.options, descriptor.FileOptions):
584 ext_type = nanopb_pb2.nanopb_fileopt
585 elif isinstance(subdesc.options, descriptor.MessageOptions):
586 ext_type = nanopb_pb2.nanopb_msgopt
587 elif isinstance(subdesc.options, descriptor.EnumOptions):
588 ext_type = nanopb_pb2.nanopb_enumopt
590 raise Exception("Unknown options type")
592 if subdesc.options.HasExtension(ext_type):
593 ext = subdesc.options.Extensions[ext_type]
594 new_options.MergeFrom(ext)
598 def process(filenames, options):
599 '''Process the files given on the command line.'''
602 optparser.print_help()
606 options.verbose = False
608 toplevel_options = nanopb_pb2.NanoPBOptions()
609 for s in options.settings:
610 text_format.Merge(s, toplevel_options)
612 for filename in filenames:
613 data = open(filename, 'rb').read()
614 fdesc = descriptor.FileDescriptorSet.FromString(data)
616 file_options = get_nanopb_suboptions(fdesc.file[0], toplevel_options)
619 print "Options for " + filename + ":"
620 print text_format.MessageToString(file_options)
622 enums, messages = parse_file(fdesc.file[0], file_options)
624 noext = os.path.splitext(filename)[0]
625 headername = noext + '.pb.h'
626 sourcename = noext + '.pb.c'
627 headerbasename = os.path.basename(headername)
629 if not options.quiet:
630 print "Writing to " + headername + " and " + sourcename
632 # List of .proto files that should not be included in the C header file
633 # even if they are mentioned in the source .proto.
634 excludes = ['nanopb.proto', 'google/protobuf/descriptor.proto'] + options.exclude
635 dependencies = [d for d in fdesc.file[0].dependency if d not in excludes]
637 header = open(headername, 'w')
638 for part in generate_header(dependencies, headerbasename, enums, messages):
641 source = open(sourcename, 'w')
642 for part in generate_source(headerbasename, enums, messages):
647 if __name__ == '__main__':
648 options, filenames = optparser.parse_args()
649 status = process(filenames, options)