/generator/nanopb_generator.py
Python | 436 lines | 395 code | 30 blank | 11 comment | 20 complexity | a74bf27f232191176abf15d5b71da41f MD5 | raw file
- '''Generate header file for nanopb from a ProtoBuf FileDescriptorSet.'''
- import google.protobuf.descriptor_pb2 as descriptor
- import nanopb_pb2
- import os.path
- # Values are tuple (c type, pb ltype)
- FieldD = descriptor.FieldDescriptorProto
- datatypes = {
- FieldD.TYPE_BOOL: ('bool', 'PB_LTYPE_VARINT'),
- FieldD.TYPE_DOUBLE: ('double', 'PB_LTYPE_FIXED64'),
- FieldD.TYPE_FIXED32: ('uint32_t', 'PB_LTYPE_FIXED32'),
- FieldD.TYPE_FIXED64: ('uint64_t', 'PB_LTYPE_FIXED64'),
- FieldD.TYPE_FLOAT: ('float', 'PB_LTYPE_FIXED32'),
- FieldD.TYPE_INT32: ('int32_t', 'PB_LTYPE_VARINT'),
- FieldD.TYPE_INT64: ('int64_t', 'PB_LTYPE_VARINT'),
- FieldD.TYPE_SFIXED32: ('int32_t', 'PB_LTYPE_FIXED32'),
- FieldD.TYPE_SFIXED64: ('int64_t', 'PB_LTYPE_FIXED64'),
- FieldD.TYPE_SINT32: ('int32_t', 'PB_LTYPE_SVARINT'),
- FieldD.TYPE_SINT64: ('int64_t', 'PB_LTYPE_SVARINT'),
- FieldD.TYPE_UINT32: ('uint32_t', 'PB_LTYPE_VARINT'),
- FieldD.TYPE_UINT64: ('uint64_t', 'PB_LTYPE_VARINT')
- }
- 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 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):
- '''desc is EnumDescriptorProto'''
- self.names = names + desc.name
- self.values = [(self.names + x.name, x.number) for x in desc.value]
-
- def __str__(self):
- result = 'typedef enum {\n'
- 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):
- '''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 nanopb-specific field options
- if desc.options.HasExtension(nanopb_pb2.nanopb):
- ext = desc.options.Extensions[nanopb_pb2.nanopb]
- if ext.HasField("max_size"):
- self.max_size = ext.max_size
- if ext.HasField("max_count"):
- self.max_count = ext.max_count
-
- if desc.HasField('default_value'):
- self.default = desc.default_value
-
- # Decide HTYPE
- # HTYPE is the high-order nibble of nanopb field description,
- # defining whether value is required/optional/repeated.
- is_callback = False
- if desc.label == FieldD.LABEL_REQUIRED:
- self.htype = 'PB_HTYPE_REQUIRED'
- elif desc.label == FieldD.LABEL_OPTIONAL:
- self.htype = 'PB_HTYPE_OPTIONAL'
- elif desc.label == FieldD.LABEL_REPEATED:
- if self.max_count is None:
- is_callback = True
- else:
- self.htype = 'PB_HTYPE_ARRAY'
- self.array_decl = '[%d]' % self.max_count
- else:
- raise NotImplementedError(desc.label)
-
- # Decide LTYPE and CTYPE
- # LTYPE is the low-order nibble of nanopb field description,
- # defining how to decode an individual value.
- # CTYPE is the name of the c type to use in the struct.
- if datatypes.has_key(desc.type):
- self.ctype, self.ltype = datatypes[desc.type]
- elif desc.type == FieldD.TYPE_ENUM:
- self.ltype = 'PB_LTYPE_VARINT'
- 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.ltype = 'PB_LTYPE_STRING'
- if self.max_size is None:
- is_callback = True
- else:
- self.ctype = 'char'
- self.array_decl += '[%d]' % self.max_size
- elif desc.type == FieldD.TYPE_BYTES:
- self.ltype = 'PB_LTYPE_BYTES'
- if self.max_size is None:
- is_callback = True
- else:
- self.ctype = self.struct_name + self.name + 't'
- elif desc.type == FieldD.TYPE_MESSAGE:
- self.ltype = 'PB_LTYPE_SUBMESSAGE'
- self.ctype = self.submsgname = names_from_type_name(desc.type_name)
- else:
- raise NotImplementedError(desc.type)
-
- if is_callback:
- self.htype = 'PB_HTYPE_CALLBACK'
- self.ctype = 'pb_callback_t'
- self.array_decl = ''
-
- def __cmp__(self, other):
- return cmp(self.tag, other.tag)
-
- def __str__(self):
- if self.htype == 'PB_HTYPE_OPTIONAL':
- result = ' bool has_' + self.name + ';\n'
- elif self.htype == 'PB_HTYPE_ARRAY':
- 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.ltype == 'PB_LTYPE_BYTES' and self.max_size is not None:
- 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
-
- if self.ltype == 'PB_LTYPE_STRING':
- ctype = 'char'
- if self.max_size is None:
- return None # Not implemented
- else:
- array_decl = '[%d]' % (self.max_size + 1)
- default = str(self.default).encode('string_escape')
- default = default.replace('"', '\\"')
- default = '"' + default + '"'
- elif self.ltype == 'PB_LTYPE_BYTES':
- data = self.default.decode('string_escape')
- data = ['0x%02x' % ord(c) for c in data]
-
- if self.max_size is None:
- return None # Not implemented
- else:
- ctype = self.ctype
-
- default = '{%d, {%s}}' % (len(data), ','.join(data))
- array_decl = ''
- else:
- ctype, default = self.ctype, self.default
- array_decl = ''
-
- 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 = ' {%d, ' % self.tag
- result += self.htype
- if self.ltype is not None:
- result += ' | ' + self.ltype
- result += ',\n'
-
- if prev_field_name is None:
- result += ' offsetof(%s, %s),' % (self.struct_name, self.name)
- else:
- result += ' pb_delta_end(%s, %s, %s),' % (self.struct_name, self.name, prev_field_name)
-
- if self.htype == 'PB_HTYPE_OPTIONAL':
- result += '\n pb_delta(%s, has_%s, %s),' % (self.struct_name, self.name, self.name)
- elif self.htype == 'PB_HTYPE_ARRAY':
- result += '\n pb_delta(%s, %s_count, %s),' % (self.struct_name, self.name, self.name)
- else:
- result += ' 0,'
-
-
- if self.htype == 'PB_HTYPE_ARRAY':
- result += '\n pb_membersize(%s, %s[0]),' % (self.struct_name, self.name)
- result += ('\n pb_membersize(%s, %s) / pb_membersize(%s, %s[0]),'
- % (self.struct_name, self.name, self.struct_name, self.name))
- else:
- result += '\n pb_membersize(%s, %s),' % (self.struct_name, self.name)
- result += ' 0,'
-
- if self.ltype == 'PB_LTYPE_SUBMESSAGE':
- result += '\n &%s_fields}' % self.submsgname
- elif self.default is None or self.htype == 'PB_HTYPE_CALLBACK':
- result += ' 0}'
- else:
- result += '\n &%s_default}' % (self.struct_name + self.name)
-
- return result
- class Message:
- def __init__(self, names, desc):
- self.name = names
- self.fields = [Field(self.name, f) for f in desc.field]
- 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 {\n'
- result += '\n'.join([str(f) for f in self.ordered_fields])
- result += '\n} %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\n'
- prev = field.name
-
- result += ' PB_LAST_FIELD\n};'
- return result
- 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):
- '''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:
- enums.append(Enum(base_name, enum))
-
- for names, message in iterate_messages(fdesc, base_name):
- messages.append(Message(names, message))
- for enum in message.enum_type:
- enums.append(Enum(names, enum))
-
- 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(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 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'
-
- symbol = headername.replace('.', '_').upper()
- yield '#ifndef _PB_%s_\n' % symbol
- yield '#define _PB_%s_\n' % symbol
- yield '#include <pb.h>\n\n'
-
- for dependency in dependencies:
- noext = os.path.splitext(dependency)[0]
- yield '#include "%s.pb.h"\n' % noext
- yield '\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#endif\n'
- def generate_source(headername, enums, messages):
- '''Generate content for a source file.'''
-
- yield '/* Automatically generated nanopb constant definitions */\n'
- 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 __name__ == '__main__':
- import sys
- import os.path
-
- if len(sys.argv) != 2:
- print "Usage: " + sys.argv[0] + " file.pb"
- print "where file.pb has been compiled from .proto by:"
- print "protoc -ofile.pb file.proto"
- print "Output fill be written to file.pb.h and file.pb.c"
- sys.exit(1)
-
- data = open(sys.argv[1], 'rb').read()
- fdesc = descriptor.FileDescriptorSet.FromString(data)
- enums, messages = parse_file(fdesc.file[0])
-
- noext = os.path.splitext(sys.argv[1])[0]
- headername = noext + '.pb.h'
- sourcename = noext + '.pb.c'
- headerbasename = os.path.basename(headername)
-
- 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']
- 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)
-