diff options
Diffstat (limited to 'Lib/importlib')
| -rw-r--r-- | Lib/importlib/_bootstrap_external.py | 28 | ||||
| -rw-r--r-- | Lib/importlib/util.py | 2 |
2 files changed, 27 insertions, 3 deletions
diff --git a/Lib/importlib/_bootstrap_external.py b/Lib/importlib/_bootstrap_external.py index e54d691..506bb33 100644 --- a/Lib/importlib/_bootstrap_external.py +++ b/Lib/importlib/_bootstrap_external.py @@ -230,7 +230,7 @@ _code_type = type(_write_atomic.__code__) # Python 3.5b1 3330 (PEP 448: Additional Unpacking Generalizations) # Python 3.5b2 3340 (fix dictionary display evaluation order #11205) # Python 3.5b2 3350 (add GET_YIELD_FROM_ITER opcode #24400) -# Python 3.5.2 3351 (fix BUILD_MAP_UNPACK_WITH_CALL opcode #27286) +# Python 3.5.3 3351 (fix BUILD_MAP_UNPACK_WITH_CALL opcode #27286) # # MAGIC must change whenever the bytecode emitted by the compiler may no # longer be understood by older implementations of the eval loop (usually @@ -242,6 +242,28 @@ _code_type = type(_write_atomic.__code__) MAGIC_NUMBER = (3351).to_bytes(2, 'little') + b'\r\n' _RAW_MAGIC_NUMBER = int.from_bytes(MAGIC_NUMBER, 'little') # For import.c +# Issue #29537: handle issue27286 bytecode incompatibility +# +# The magic number bump in Python 3.5.3 for issue27286 turned out to create +# significant backwards compatibility problems for redistributors and +# other folks that rely on the bytecode format remaining stable within a +# given maintenance release series. See http://bugs.python.org/issue29514 +# for more discussion of the problems that the original change caused. +# +# The _BACKCOMPAT_MAGIC_NUMBER below and any other changes marked with +# "Issue #29537" comments allow Python 3.5.4+ to load bytecode files with both +# the original 3.5.0 magic number and those with the updated magic number used +# since 3.5.3. +# +# This is expected to be a one-off change used solely to restore legacy +# bytecode compatibility within the 3.5.x series, so it avoids any changes +# that would prompt a rebuild of C extension modules. +# +if _RAW_MAGIC_NUMBER != 168627479: + _msg = 'Magic number mismatch (the issue27286 workaround is for 3.5 only)' + raise SystemError(_msg) +_BACKCOMPAT_MAGIC_NUMBER = (3350).to_bytes(2, 'little') + b'\r\n' + _PYCACHE = '__pycache__' _OPT = 'opt-' @@ -446,7 +468,9 @@ def _validate_bytecode_header(data, source_stats=None, name=None, path=None): magic = data[:4] raw_timestamp = data[4:8] raw_size = data[8:12] - if magic != MAGIC_NUMBER: + if (magic != MAGIC_NUMBER + # Issue #29537: handle issue27286 bytecode incompatibility + and magic != _BACKCOMPAT_MAGIC_NUMBER): message = 'bad magic number in {!r}: {!r}'.format(name, magic) _verbose_message('{}', message) raise ImportError(message, **exc_details) diff --git a/Lib/importlib/util.py b/Lib/importlib/util.py index e1fa07a..a15cf00 100644 --- a/Lib/importlib/util.py +++ b/Lib/importlib/util.py @@ -4,7 +4,7 @@ from ._bootstrap import module_from_spec from ._bootstrap import _resolve_name from ._bootstrap import spec_from_loader from ._bootstrap import _find_spec -from ._bootstrap_external import MAGIC_NUMBER +from ._bootstrap_external import MAGIC_NUMBER, _BACKCOMPAT_MAGIC_NUMBER from ._bootstrap_external import cache_from_source from ._bootstrap_external import decode_source from ._bootstrap_external import source_from_cache |