diff options
Diffstat (limited to 'Lib/importlib/_bootstrap.py')
| -rw-r--r-- | Lib/importlib/_bootstrap.py | 139 |
1 files changed, 73 insertions, 66 deletions
diff --git a/Lib/importlib/_bootstrap.py b/Lib/importlib/_bootstrap.py index f9d9ad4..49263a5 100644 --- a/Lib/importlib/_bootstrap.py +++ b/Lib/importlib/_bootstrap.py @@ -623,6 +623,71 @@ def _find_module_shim(self, fullname): return loader +def _validate_bytecode_header(data, source_stats=None, name=None, path=None): + """Validate the header of the passed-in bytecode against source_stats (if + given) and returning the bytecode that can be compiled by compile(). + + All other arguments are used to enhance error reporting. + + ImportError is raised when the magic number is incorrect or the bytecode is + found to be stale. EOFError is raised when the data is found to be + truncated. + + """ + exc_details = {} + if name is not None: + exc_details['name'] = name + else: + # To prevent having to make all messages have a conditional name. + name = 'bytecode' + if path is not None: + exc_details['path'] = path + magic = data[:4] + raw_timestamp = data[4:8] + raw_size = data[8:12] + if magic != _MAGIC_BYTES: + msg = 'bad magic number in {!r}: {!r}'.format(name, magic) + raise ImportError(msg, **exc_details) + elif len(raw_timestamp) != 4: + message = 'bad timestamp in {!r}'.format(name) + _verbose_message(message) + raise EOFError(message) + elif len(raw_size) != 4: + message = 'bad size in {!r}'.format(name) + _verbose_message(message) + raise EOFError(message) + if source_stats is not None: + try: + source_mtime = int(source_stats['mtime']) + except KeyError: + pass + else: + if _r_long(raw_timestamp) != source_mtime: + message = 'bytecode is stale for {!r}'.format(name) + _verbose_message(message) + raise ImportError(message, **exc_details) + try: + source_size = source_stats['size'] & 0xFFFFFFFF + except KeyError: + pass + else: + if _r_long(raw_size) != source_size: + raise ImportError("bytecode is stale for {!r}".format(name), + **exc_details) + return data[12:] + + +def _compile_bytecode(data, name=None, bytecode_path=None, source_path=None): + """Compile bytecode as returned by _validate_bytecode_header().""" + code = marshal.loads(data) + if isinstance(code, _code_type): + _verbose_message('code object from {!r}', bytecode_path) + if source_path is not None: + _imp._fix_co_filename(code, source_path) + return code + else: + raise ImportError("Non-code object in {!r}".format(bytecode_path), + name=name, path=bytecode_path) # Loaders ##################################################################### @@ -801,51 +866,6 @@ class _LoaderBasics: tail_name = fullname.rpartition('.')[2] return filename_base == '__init__' and tail_name != '__init__' - def _bytes_from_bytecode(self, fullname, data, bytecode_path, source_stats): - """Return the marshalled bytes from bytecode, verifying the magic - number, timestamp and source size along the way. - - If source_stats is None then skip the timestamp check. - - """ - magic = data[:4] - raw_timestamp = data[4:8] - raw_size = data[8:12] - if magic != _MAGIC_BYTES: - msg = 'bad magic number in {!r}: {!r}'.format(fullname, magic) - raise ImportError(msg, name=fullname, path=bytecode_path) - elif len(raw_timestamp) != 4: - message = 'bad timestamp in {}'.format(fullname) - _verbose_message(message) - raise EOFError(message) - elif len(raw_size) != 4: - message = 'bad size in {}'.format(fullname) - _verbose_message(message) - raise EOFError(message) - if source_stats is not None: - try: - source_mtime = int(source_stats['mtime']) - except KeyError: - pass - else: - if _r_long(raw_timestamp) != source_mtime: - message = 'bytecode is stale for {}'.format(fullname) - _verbose_message(message) - raise ImportError(message, name=fullname, - path=bytecode_path) - try: - source_size = source_stats['size'] & 0xFFFFFFFF - except KeyError: - pass - else: - if _r_long(raw_size) != source_size: - raise ImportError( - "bytecode is stale for {}".format(fullname), - name=fullname, path=bytecode_path) - # Can't return the code object as errors from marshal loading need to - # propagate even when source is available. - return data[12:] - @module_for_loader def _load_module(self, module, *, sourceless=False): """Helper for load_module able to handle either source or sourceless @@ -965,24 +985,17 @@ class SourceLoader(_LoaderBasics): pass else: try: - bytes_data = self._bytes_from_bytecode(fullname, data, - bytecode_path, - st) + bytes_data = _validate_bytecode_header(data, + source_stats=st, name=fullname, + path=bytecode_path) except (ImportError, EOFError): pass else: _verbose_message('{} matches {}', bytecode_path, source_path) - found = marshal.loads(bytes_data) - if isinstance(found, _code_type): - _imp._fix_co_filename(found, source_path) - _verbose_message('code object from {}', - bytecode_path) - return found - else: - msg = "Non-code object in {}" - raise ImportError(msg.format(bytecode_path), - name=fullname, path=bytecode_path) + return _compile_bytecode(bytes_data, name=fullname, + bytecode_path=bytecode_path, + source_path=source_path) source_bytes = self.get_data(source_path) code_object = self.source_to_code(source_bytes, source_path) _verbose_message('code object from {}', source_path) @@ -1098,14 +1111,8 @@ class SourcelessFileLoader(FileLoader, _LoaderBasics): def get_code(self, fullname): path = self.get_filename(fullname) data = self.get_data(path) - bytes_data = self._bytes_from_bytecode(fullname, data, path, None) - found = marshal.loads(bytes_data) - if isinstance(found, _code_type): - _verbose_message('code object from {!r}', path) - return found - else: - raise ImportError("Non-code object in {}".format(path), - name=fullname, path=path) + bytes_data = _validate_bytecode_header(data, name=fullname, path=path) + return _compile_bytecode(bytes_data, name=fullname, bytecode_path=path) def get_source(self, fullname): """Return None as there is no source code.""" |