'''Generate header file for nanopb from a ProtoBuf FileDescriptorSet.''' nanopb_version = "0.2.0-dev" try: import google.protobuf.descriptor_pb2 as descriptor except: print print "*************************************************************" print "*** Could not import the Google protobuf Python libraries ***" print "*** Try installing package 'python-protobuf' or similar. ***" print "*************************************************************" print raise try: import nanopb_pb2 except: print print "***************************************************************" print "*** Could not import the precompiled nanopb_pb2.py. ***" print "*** Run 'make' in the 'generator' folder to update the file.***" print "***************************************************************" print raise # --------------------------------------------------------------------------- # Generation of single fields # --------------------------------------------------------------------------- import time import os.path # Values are tuple (c type, pb type) FieldD = descriptor.FieldDescriptorProto datatypes = { FieldD.TYPE_BOOL: ('bool', 'BOOL'), FieldD.TYPE_DOUBLE: ('double', 'DOUBLE'), FieldD.TYPE_FIXED32: ('uint32_t', 'FIXED32'), FieldD.TYPE_FIXED64: ('uint64_t', 'FIXED64'), FieldD.TYPE_FLOAT: ('float', 'FLOAT'), FieldD.TYPE_INT32: ('int32_t', 'INT32'), FieldD.TYPE_INT64: ('int64_t', 'INT64'), FieldD.TYPE_SFIXED32: ('int32_t', 'SFIXED32'), FieldD.TYPE_SFIXED64: ('int64_t', 'SFIXED64'), FieldD.TYPE_SINT32: ('int32_t', 'SINT32'), FieldD.TYPE_SINT64: ('int64_t', 'SINT64'), FieldD.TYPE_UINT32: ('uint32_t', 'UINT32'), FieldD.TYPE_UINT64: ('uint64_t', 'UINT64') } class Names: '''Keeps a set of nested names and formats them to C identifier. You can subclass this with your own implementation. ''' def __init__(self, parts = ()): if isinstance(parts, Names): parts = parts.parts self.parts = tuple(parts) def __str__(self): return '_'.join(self.parts) def __add__(self, other): if isinstance(other, (str, unicode)): return Names(self.parts + (other,)) elif isinstance(other, tuple): return Names(self.parts + other) else: raise ValueError("Name parts should be of type str") def __eq__(self, other): return isinstance(other, Names) and self.parts == other.parts def names_from_type_name(type_name): '''Parse Names() from FieldDescriptorProto type_name''' if type_name[0] != '.': raise NotImplementedError("Lookup of non-absolute type names is not supported") return Names(type_name[1:].split('.')) class Enum: def __init__(self, names, desc, enum_options): '''desc is EnumDescriptorProto''' self.options = enum_options self.names = names + desc.name if enum_options.long_names: self.values = [(self.names + x.name, x.number) for x in desc.value] else: self.values = [(names + x.name, x.number) for x in desc.value] self.value_longnames = [self.names + x.name for x in desc.value] def __str__(self): result = 'typedef enum _%s {\n' % self.names result += ',\n'.join([" %s = %d" % x for x in self.values]) result += '\n} %s;' % self.names return result class Field: def __init__(self, struct_name, desc, field_options): '''desc is FieldDescriptorProto''' self.tag = desc.number self.struct_name = struct_name self.name = desc.name self.default = None self.max_size = None self.max_count = None self.array_decl = "" # Parse field options if field_options.HasField("max_size"): self.max_size = field_options.max_size if field_options.HasField("max_count"): self.max_count = field_options.max_count if desc.HasField('default_value'): self.default = desc.default_value # Check field rules, i.e. required/optional/repeated. can_be_static = True if desc.label == FieldD.LABEL_REQUIRED: self.rules = 'REQUIRED' elif desc.label == FieldD.LABEL_OPTIONAL: self.rules = 'OPTIONAL' elif desc.label == FieldD.LABEL_REPEATED: self.rules = 'REPEATED' if self.max_count is None: can_be_static = False else: self.array_decl = '[%d]' % self.max_count else: raise NotImplementedError(desc.label) # Decide the C data type to use in the struct. if datatypes.has_key(desc.type): self.ctype, self.pbtype = datatypes[desc.type] elif desc.type == FieldD.TYPE_ENUM: self.pbtype = 'ENUM' self.ctype = names_from_type_name(desc.type_name) if self.default is not None: self.default = self.ctype + self.default elif desc.type == FieldD.TYPE_STRING: self.pbtype = 'STRING' if self.max_size is None: can_be_static = False else: self.ctype = 'char' self.array_decl += '[%d]' % self.max_size elif desc.type == FieldD.TYPE_BYTES: self.pbtype = 'BYTES' if self.max_size is None: can_be_static = False else: self.ctype = self.struct_name + self.name + 't' elif desc.type == FieldD.TYPE_MESSAGE: self.pbtype = 'MESSAGE' self.ctype = self.submsgname = names_from_type_name(desc.type_name) else: raise NotImplementedError(desc.type) if field_options.type == nanopb_pb2.FT_DEFAULT: if can_be_static: field_options.type = nanopb_pb2.FT_STATIC else: field_options.type = nanopb_pb2.FT_CALLBACK if field_options.type == nanopb_pb2.FT_STATIC and not can_be_static: raise Exception("Field %s is defined as static, but max_size or max_count is not given." % self.name) if field_options.type == nanopb_pb2.FT_STATIC: self.allocation = 'STATIC' elif field_options.type == nanopb_pb2.FT_CALLBACK: self.allocation = 'CALLBACK' self.ctype = 'pb_callback_t' self.array_decl = '' else: raise NotImplementedError(field_options.type) def __cmp__(self, other): return cmp(self.tag, other.tag) def __str__(self): if self.rules == 'OPTIONAL': result = ' bool has_' + self.name + ';\n' elif self.rules == 'REPEATED' and self.allocation == 'STATIC': result = ' size_t ' + self.name + '_count;\n' else: result = '' result += ' %s %s%s;' % (self.ctype, self.name, self.array_decl) return result def types(self): '''Return definitions for any special types this field might need.''' if self.pbtype == 'BYTES' and self.allocation == 'STATIC': result = 'typedef struct {\n' result += ' size_t size;\n' result += ' uint8_t bytes[%d];\n' % self.max_size result += '} %s;\n' % self.ctype else: result = None return result def default_decl(self, declaration_only = False): '''Return definition for this field's default value.''' if self.default is None: return None ctype, default = self.ctype, self.default array_decl = '' if self.pbtype == 'STRING': if self.allocation != 'STATIC': return None # Not implemented array_decl = '[%d]' % self.max_size default = str(self.default).encode('string_escape') default = default.replace('"', '\\"') default = '"' + default + '"' elif self.pbtype == 'BYTES': if self.allocation != 'STATIC': return None # Not implemented data = self.default.decode('string_escape') data = ['0x%02x' % ord(c) for c in data] default = '{%d, {%s}}' % (len(data), ','.join(data)) if declaration_only: return 'extern const %s %s_default%s;' % (ctype, self.struct_name + self.name, array_decl) else: return 'const %s %s_default%s = %s;' % (ctype, self.struct_name + self.name, array_decl, default) def pb_field_t(self, prev_field_name): '''Return the pb_field_t initializer to use in the constant array. prev_field_name is the name of the previous field or None. ''' result = ' PB_FIELD(%3d, ' % self.tag result += '%-8s, ' % self.pbtype result += '%s, ' % self.rules result += '%s, ' % self.allocation result += '%s, ' % self.struct_name result += '%s, ' % self.name result += '%s, ' % (prev_field_name or self.name) if self.pbtype == 'MESSAGE': result += '&%s_fields)' % self.submsgname elif self.default is None: result += '0)' elif self.pbtype in ['BYTES', 'STRING'] and self.allocation != 'STATIC': result += '0)' # Arbitrary size default values not implemented else: result += '&%s_default)' % (self.struct_name + self.name) return result def largest_field_value(self): '''Determine if this field needs 16bit or 32bit pb_field_t structure to compile properly. Returns numeric value or a C-expression for assert.''' if self.pbtype == 'MESSAGE': if self.rules == 'REPEATED' and self.allocation == 'STATIC': return 'pb_membersize(%s, %s[0])' % (self.struct_name, self.name) else: return 'pb_membersize(%s, %s)' % (self.struct_name, self.name) return max(self.tag, self.max_size, self.max_count) # --------------------------------------------------------------------------- # Generation of messages (structures) # --------------------------------------------------------------------------- class Message: def __init__(self, names, desc, message_options): self.name = names self.fields = [] for f in desc.field: field_options = get_nanopb_suboptions(f, message_options) if field_options.type != nanopb_pb2.FT_IGNORE: self.fields.append(Field(self.name, f, field_options)) self.packed = message_options.packed_struct self.ordered_fields = self.fields[:] self.ordered_fields.sort() def get_dependencies(self): '''Get list of type names that this structure refers to.''' return [str(field.ctype) for field in self.fields] def __str__(self): result = 'typedef struct _%s {\n' % self.name result += '\n'.join([str(f) for f in self.ordered_fields]) result += '\n}' if self.packed: result += ' pb_packed' result += ' %s;' % self.name return result def types(self): result = "" for field in self.fields: types = field.types() if types is not None: result += types + '\n' return result def default_decl(self, declaration_only = False): result = "" for field in self.fields: default = field.default_decl(declaration_only) if default is not None: result += default + '\n' return result def fields_declaration(self): result = 'extern const pb_field_t %s_fields[%d];' % (self.name, len(self.fields) + 1) return result def fields_definition(self): result = 'const pb_field_t %s_fields[%d] = {\n' % (self.name, len(self.fields) + 1) prev = None for field in self.ordered_fields: result += field.pb_field_t(prev) result += ',\n' prev = field.name result += ' PB_LAST_FIELD\n};' return result # --------------------------------------------------------------------------- # Processing of entire .proto files # --------------------------------------------------------------------------- def iterate_messages(desc, names = Names()): '''Recursively find all messages. For each, yield name, DescriptorProto.''' if hasattr(desc, 'message_type'): submsgs = desc.message_type else: submsgs = desc.nested_type for submsg in submsgs: sub_names = names + submsg.name yield sub_names, submsg for x in iterate_messages(submsg, sub_names): yield x def parse_file(fdesc, file_options): '''Takes a FileDescriptorProto and returns tuple (enum, messages).''' enums = [] messages = [] if fdesc.package: base_name = Names(fdesc.package.split('.')) else: base_name = Names() for enum in fdesc.enum_type: enum_options = get_nanopb_suboptions(enum, file_options) enums.append(Enum(base_name, enum, enum_options)) for names, message in iterate_messages(fdesc, base_name): message_options = get_nanopb_suboptions(message, file_options) messages.append(Message(names, message, message_options)) for enum in message.enum_type: enum_options = get_nanopb_suboptions(enum, message_options) enums.append(Enum(names, enum, enum_options)) # Fix field default values where enum short names are used. for enum in enums: if not enum.options.long_names: for message in messages: for field in message.fields: if field.default in enum.value_longnames: idx = enum.value_longnames.index(field.default) field.default = enum.values[idx][0] return enums, messages def toposort2(data): '''Topological sort. From http://code.activestate.com/recipes/577413-topological-sort/ This function is under the MIT license. ''' for k, v in data.items(): v.discard(k) # Ignore self dependencies extra_items_in_deps = reduce(set.union, data.values(), set()) - set(data.keys()) data.update(dict([(item, set()) for item in extra_items_in_deps])) while True: ordered = set(item for item,dep in data.items() if not dep) if not ordered: break for item in sorted(ordered): yield item data = dict([(item, (dep - ordered)) for item,dep in data.items() if item not in ordered]) assert not data, "A cyclic dependency exists amongst %r" % data def sort_dependencies(messages): '''Sort a list of Messages based on dependencies.''' dependencies = {} message_by_name = {} for message in messages: dependencies[str(message.name)] = set(message.get_dependencies()) message_by_name[str(message.name)] = message for msgname in toposort2(dependencies): if msgname in message_by_name: yield message_by_name[msgname] def make_identifier(headername): '''Make #ifndef identifier that contains uppercase A-Z and digits 0-9''' result = "" for c in headername.upper(): if c.isalnum(): result += c else: result += '_' return result def generate_header(dependencies, headername, enums, messages): '''Generate content for a header file. Generates strings, which should be concatenated and stored to file. ''' yield '/* Automatically generated nanopb header */\n' yield '/* Generated by %s at %s. */\n\n' % (nanopb_version, time.asctime()) symbol = make_identifier(headername) yield '#ifndef _PB_%s_\n' % symbol yield '#define _PB_%s_\n' % symbol yield '#include \n\n' for dependency in dependencies: noext = os.path.splitext(dependency)[0] yield '#include "%s.pb.h"\n' % noext yield '#ifdef __cplusplus\n' yield 'extern "C" {\n' yield '#endif\n\n' yield '/* Enum definitions */\n' for enum in enums: yield str(enum) + '\n\n' yield '/* Struct definitions */\n' for msg in sort_dependencies(messages): yield msg.types() yield str(msg) + '\n\n' yield '/* Default values for struct fields */\n' for msg in messages: yield msg.default_decl(True) yield '\n' yield '/* Struct field encoding specification for nanopb */\n' for msg in messages: yield msg.fields_declaration() + '\n' yield '\n#ifdef __cplusplus\n' yield '} /* extern "C" */\n' yield '#endif\n' # End of header yield '\n#endif\n' def generate_source(headername, enums, messages): '''Generate content for a source file.''' yield '/* Automatically generated nanopb constant definitions */\n' yield '/* Generated by %s at %s. */\n\n' % (nanopb_version, time.asctime()) yield '#include "%s"\n\n' % headername for msg in messages: yield msg.default_decl(False) yield '\n\n' for msg in messages: yield msg.fields_definition() + '\n\n' if messages: count_required_fields = lambda m: len([f for f in msg.fields if f.rules == 'REQUIRED']) largest_msg = max(messages, key = count_required_fields) largest_count = count_required_fields(largest_msg) if largest_count > 64: yield '\n/* Check that missing required fields will be properly detected */\n' yield '#if PB_MAX_REQUIRED_FIELDS < %d\n' % largest_count yield '#error Properly detecting missing required fields in %s requires \\\n' % largest_msg.name yield ' setting PB_MAX_REQUIRED_FIELDS to %d or more.\n' % largest_count yield '#endif\n' # Add checks for numeric limits worst = 0 worst_field = '' checks = [] checks_msgnames = [] for msg in messages: checks_msgnames.append(msg.name) for field in msg.fields: status = field.largest_field_value() if isinstance(status, (str, unicode)): checks.append(status) elif status > worst: worst = status worst_field = str(field.struct_name) + '.' + str(field.name) if worst > 255 or checks: yield '\n/* Check that field information fits in pb_field_t */\n' if worst < 65536: yield '#if !defined(PB_FIELD_16BIT) && !defined(PB_FIELD_32BIT)\n' if worst > 255: yield '#error Field descriptor for %s is too large. Define PB_FIELD_16BIT to fix this.\n' % worst_field else: assertion = ' && '.join(str(c) + ' < 256' for c in checks) msgs = '_'.join(str(n) for n in checks_msgnames) yield 'STATIC_ASSERT((%s), YOU_MUST_DEFINE_PB_FIELD_16BIT_FOR_MESSAGES_%s)\n'%(assertion,msgs) yield '#endif\n\n' if worst > 65535 or checks: yield '#if !defined(PB_FIELD_32BIT)\n' if worst > 65535: yield '#error Field descriptor for %s is too large. Define PB_FIELD_32BIT to fix this.\n' % worst_field else: assertion = ' && '.join(str(c) + ' < 65536' for c in checks) msgs = '_'.join(str(n) for n in checks_msgnames) yield 'STATIC_ASSERT((%s), YOU_MUST_DEFINE_PB_FIELD_32BIT_FOR_MESSAGES_%s)\n'%(assertion,msgs) yield '#endif\n' # Add check for sizeof(double) has_double = False for msg in messages: for field in msg.fields: if field.ctype == 'double': has_double = True if has_double: yield '\n' yield '/* On some platforms (such as AVR), double is really float.\n' yield ' * These are not directly supported by nanopb, but see example_avr_double.\n' yield ' * To get rid of this error, remove any double fields from your .proto.\n' yield ' */\n' yield 'STATIC_ASSERT(sizeof(double) == 8, DOUBLE_MUST_BE_8_BYTES)\n' yield '\n' # --------------------------------------------------------------------------- # Command line interface # --------------------------------------------------------------------------- import sys import os.path from optparse import OptionParser import google.protobuf.text_format as text_format optparser = OptionParser( usage = "Usage: nanopb_generator.py [options] file.pb ...", epilog = "Compile file.pb from file.proto by: 'protoc -ofile.pb file.proto'. " + "Output will be written to file.pb.h and file.pb.c.") optparser.add_option("-x", dest="exclude", metavar="FILE", action="append", default=[], help="Exclude file from generated #include list.") optparser.add_option("-q", "--quiet", dest="quiet", action="store_true", default=False, help="Don't print anything except errors.") optparser.add_option("-v", "--verbose", dest="verbose", action="store_true", default=False, help="Print more information.") optparser.add_option("-s", dest="settings", metavar="OPTION:VALUE", action="append", default=[], help="Set generator option (max_size, max_count etc.).") def get_nanopb_suboptions(subdesc, options): '''Get copy of options, and merge information from subdesc.''' new_options = nanopb_pb2.NanoPBOptions() new_options.CopyFrom(options) if isinstance(subdesc.options, descriptor.FieldOptions): ext_type = nanopb_pb2.nanopb elif isinstance(subdesc.options, descriptor.FileOptions): ext_type = nanopb_pb2.nanopb_fileopt elif isinstance(subdesc.options, descriptor.MessageOptions): ext_type = nanopb_pb2.nanopb_msgopt elif isinstance(subdesc.options, descriptor.EnumOptions): ext_type = nanopb_pb2.nanopb_enumopt else: raise Exception("Unknown options type") if subdesc.options.HasExtension(ext_type): ext = subdesc.options.Extensions[ext_type] new_options.MergeFrom(ext) return new_options def process(filenames, options): '''Process the files given on the command line.''' if not filenames: optparser.print_help() return False if options.quiet: options.verbose = False toplevel_options = nanopb_pb2.NanoPBOptions() for s in options.settings: text_format.Merge(s, toplevel_options) for filename in filenames: data = open(filename, 'rb').read() fdesc = descriptor.FileDescriptorSet.FromString(data) file_options = get_nanopb_suboptions(fdesc.file[0], toplevel_options) if options.verbose: print "Options for " + filename + ":" print text_format.MessageToString(file_options) enums, messages = parse_file(fdesc.file[0], file_options) noext = os.path.splitext(filename)[0] headername = noext + '.pb.h' sourcename = noext + '.pb.c' headerbasename = os.path.basename(headername) if not options.quiet: print "Writing to " + headername + " and " + sourcename # List of .proto files that should not be included in the C header file # even if they are mentioned in the source .proto. excludes = ['nanopb.proto', 'google/protobuf/descriptor.proto'] + options.exclude dependencies = [d for d in fdesc.file[0].dependency if d not in excludes] header = open(headername, 'w') for part in generate_header(dependencies, headerbasename, enums, messages): header.write(part) source = open(sourcename, 'w') for part in generate_source(headerbasename, enums, messages): source.write(part) return True if __name__ == '__main__': options, filenames = optparser.parse_args() status = process(filenames, options) if not status: sys.exit(1)