# # UAVCAN DSDL compiler for libuavcan # # Copyright (C) 2014 Pavel Kirienko # ''' This module implements the core functionality of the UAVCAN DSDL compiler for libuavcan. Supported Python versions: 3.2+, 2.7. It accepts a list of root namespaces and produces the set of C++ header files for libuavcan. It is based on the DSDL parsing package from pyuavcan. ''' from __future__ import division, absolute_import, print_function, unicode_literals import sys, os, logging, errno, re from .pyratemp import Template from pyuavcan import dsdl # Python 2.7 compatibility try: str = unicode except NameError: pass OUTPUT_FILE_EXTENSION = 'hpp' OUTPUT_FILE_PERMISSIONS = 0o444 # Read only for all TEMPLATE_FILENAME = os.path.join(os.path.dirname(__file__), 'data_type_template.tmpl') __all__ = ['run', 'logger', 'DsdlCompilerException'] class DsdlCompilerException(Exception): pass logger = logging.getLogger(__name__) def run(source_dirs, include_dirs, output_dir): ''' This function takes a list of root namespace directories (containing DSDL definition files to parse), a possibly empty list of search directories (containing DSDL definition files that can be referenced from the types that are going to be parsed), and the output directory path (possibly nonexistent) where the generated C++ header files will be stored. Note that this module features lazy write, i.e. if an output file does already exist and its content is not going to change, it will not be overwritten. This feature allows to avoid unnecessary recompilation of dependent object files. Args: source_dirs List of root namespace directories to parse. include_dirs List of root namespace directories with referenced types (possibly empty). This list is automaitcally extended with source_dirs. output_dir Output directory path. Will be created if doesn't exist. ''' assert isinstance(source_dirs, list) assert isinstance(include_dirs, list) output_dir = str(output_dir) types = run_parser(source_dirs, include_dirs + source_dirs) if not types: die('No type definitions were found') logger.info('%d types total', len(types)) run_generator(types, output_dir) # ----------------- def pretty_filename(filename): try: a = os.path.abspath(filename) r = os.path.relpath(filename) return a if '..' in r else r except ValueError: return filename def type_output_filename(t): assert t.category == t.CATEGORY_COMPOUND return t.full_name.replace('.', os.path.sep) + '.' + OUTPUT_FILE_EXTENSION def makedirs(path): try: try: os.makedirs(path, exist_ok=True) # May throw "File exists" when executed as root, which is wrong except TypeError: os.makedirs(path) # Python 2.7 compatibility except OSError as ex: if ex.errno != errno.EEXIST: # http://stackoverflow.com/questions/12468022 raise def die(text): raise DsdlCompilerException(str(text)) def run_parser(source_dirs, search_dirs): try: types = dsdl.parse_namespaces(source_dirs, search_dirs) except dsdl.DsdlException as ex: logger.info('Parser failure', exc_info=True) die(ex) return types def run_generator(types, dest_dir): try: template_expander = make_template_expander(TEMPLATE_FILENAME) dest_dir = os.path.abspath(dest_dir) # Removing '..' makedirs(dest_dir) for t in types: logger.info('Generating type %s', t.full_name) filename = os.path.join(dest_dir, type_output_filename(t)) text = generate_one_type(template_expander, t) write_generated_data(filename, text) except Exception as ex: logger.info('Generator failure', exc_info=True) die(ex) def write_generated_data(filename, data): dirname = os.path.dirname(filename) makedirs(dirname) # Lazy update - file will not be rewritten if its content is not going to change if os.path.exists(filename): with open(filename) as f: existing_data = f.read() if data == existing_data: logger.info('Up to date [%s]', pretty_filename(filename)) return logger.info('Rewriting [%s]', pretty_filename(filename)) os.remove(filename) else: logger.info('Creating [%s]', pretty_filename(filename)) # Full rewrite with open(filename, 'w') as f: f.write(data) try: os.chmod(filename, OUTPUT_FILE_PERMISSIONS) except (OSError, IOError) as ex: logger.warning('Failed to set permissions for %s: %s', pretty_filename(filename), ex) def type_to_cpp_type(t): if t.category == t.CATEGORY_PRIMITIVE: cast_mode = { t.CAST_MODE_SATURATED: '::uavcan::CastModeSaturate', t.CAST_MODE_TRUNCATED: '::uavcan::CastModeTruncate', }[t.cast_mode] if t.kind == t.KIND_FLOAT: return '::uavcan::FloatSpec< %d, %s >' % (t.bitlen, cast_mode) else: signedness = { t.KIND_BOOLEAN: '::uavcan::SignednessUnsigned', t.KIND_UNSIGNED_INT: '::uavcan::SignednessUnsigned', t.KIND_SIGNED_INT: '::uavcan::SignednessSigned', }[t.kind] return '::uavcan::IntegerSpec< %d, %s, %s >' % (t.bitlen, signedness, cast_mode) elif t.category == t.CATEGORY_ARRAY: value_type = type_to_cpp_type(t.value_type) mode = { t.MODE_STATIC: '::uavcan::ArrayModeStatic', t.MODE_DYNAMIC: '::uavcan::ArrayModeDynamic', }[t.mode] return '::uavcan::Array< %s, %s, %d >' % (value_type, mode, t.max_size) elif t.category == t.CATEGORY_COMPOUND: return '::' + t.full_name.replace('.', '::') else: raise DsdlCompilerException('Unknown type category: %s' % t.category) def generate_one_type(template_expander, t): t.short_name = t.full_name.split('.')[-1] t.cpp_type_name = t.short_name + '_' t.cpp_full_type_name = '::' + t.full_name.replace('.', '::') t.include_guard = t.full_name.replace('.', '_').upper() + '_HPP_INCLUDED' # Dependencies (no duplicates) def fields_includes(fields): def detect_include(t): if t.category == t.CATEGORY_COMPOUND: return type_output_filename(t) if t.category == t.CATEGORY_ARRAY: return detect_include(t.value_type) return list(sorted(set(filter(None, [detect_include(x.type) for x in fields])))) if t.kind == t.KIND_MESSAGE: t.cpp_includes = fields_includes(t.fields) else: t.cpp_includes = fields_includes(t.request_fields + t.response_fields) t.cpp_namespace_components = t.full_name.split('.')[:-1] t.has_default_dtid = t.default_dtid is not None # Attribute types def inject_cpp_types(attributes): for a in attributes: a.cpp_type = type_to_cpp_type(a.type) if t.kind == t.KIND_MESSAGE: inject_cpp_types(t.fields) inject_cpp_types(t.constants) t.all_attributes = t.fields + t.constants else: inject_cpp_types(t.request_fields) inject_cpp_types(t.request_constants) inject_cpp_types(t.response_fields) inject_cpp_types(t.response_constants) t.all_attributes = t.request_fields + t.request_constants + t.response_fields + t.response_constants # Constant properties def inject_constant_info(constants): for c in constants: if c.type.kind == c.type.KIND_FLOAT: float(c.string_value) # Making sure that this is a valid float literal c.cpp_value = c.string_value else: int(c.string_value) # Making sure that this is a valid integer literal c.cpp_value = c.string_value if c.type.kind == c.type.KIND_UNSIGNED_INT: c.cpp_value += 'U' if t.kind == t.KIND_MESSAGE: inject_constant_info(t.constants) else: inject_constant_info(t.request_constants) inject_constant_info(t.response_constants) # Data type kind t.cpp_kind = { t.KIND_MESSAGE: '::uavcan::DataTypeKindMessage', t.KIND_SERVICE: '::uavcan::DataTypeKindService', }[t.kind] # Generation text = template_expander(t=t) # t for Type text = '\n'.join(x.rstrip() for x in text.splitlines()) text = text.replace('\n\n\n\n\n', '\n\n').replace('\n\n\n\n', '\n\n').replace('\n\n\n', '\n\n') text = text.replace('{\n\n ', '{\n ') return text def make_template_expander(filename): ''' Templating is based on pyratemp (http://www.simple-is-better.org/template/pyratemp.html). The pyratemp's syntax is rather verbose and not so human friendly, so we define some custom extensions to make it easier to read and write. The resulting syntax somewhat resembles Mako (which was used earlier instead of pyratemp): Substitution: ${expression} Line joining through backslash (replaced with a single space): ${foo(bar(very_long_arument=42, \ second_line=72))} Blocks: % for a in range(10): % if a == 5: ${foo()} % endif % endfor The extended syntax is converted into pyratemp's through regexp substitution. ''' with open(filename) as f: template_text = f.read() # Backslash-newline elimination template_text = re.sub(r'\\\r{0,1}\n\ *', r' ', template_text) # Substitution syntax transformation: ${foo} ==> $!foo!$ template_text = re.sub(r'([^\$]{0,1})\$\{([^\}]+)\}', r'\1$!\2!$', template_text) # Flow control expression transformation: % foo: ==> template_text = re.sub(r'(?m)^(\ *)\%\ *(.+?):{0,1}$', r'\1', template_text) # Block termination transformation: ==> template_text = re.sub(r'\<\!--\(end[a-z]+\)--\>', r'', template_text) # Pyratemp workaround. # The problem is that if there's no empty line after a macro declaration, first line will be doubly indented. # Workaround: # 1. Remove trailing comments # 2. Add a newline after each macro declaration template_text = re.sub(r'\ *\#\!.*', '', template_text) template_text = re.sub(r'(\<\!--\(macro\ [a-zA-Z0-9_]+\)--\>.*?)', r'\1\n', template_text) # Preprocessed text output for debugging # with open(filename + '.d', 'w') as f: # f.write(template_text) template = Template(template_text) def expand(**args): # This function adds one indentation level (4 spaces); it will be used from the template args['indent'] = lambda text, idnt = ' ': idnt + text.replace('\n', '\n' + idnt) return template(**args) return expand