Python now supports checking bytecode cache up-to-dateness with a hash of the
source contents rather than volatile source metadata. See the PEP for details.
While a fairly straightforward idea, quite a lot of code had to be modified due
to the pervasiveness of pyc implementation details in the codebase. Changes in
this commit include:
- The core changes to importlib to understand how to read, validate, and
regenerate hash-based pycs.
- Support for generating hash-based pycs in py_compile and compileall.
- Modifications to our siphash implementation to support passing a custom
key. We then expose it to importlib through _imp.
- Updates to all places in the interpreter, standard library, and tests that
manually generate or parse pyc files to grok the new format.
- Support in the interpreter command line code for long options like
--check-hash-based-pycs.
- Tests and documentation for all of the above.
While a rare potential failure (it requires swapping out zlib.decompress() itself and forcing it to return a non-bytes object), this change prevents a potential C-level assertion failure and instead substitutes it with an exception.
Thanks to Oren Milman for the patch.
* group the (stateful) runtime globals into various topical structs
* consolidate the topical structs under a single top-level _PyRuntimeState struct
* add a check-c-globals.py script that helps identify runtime globals
Other globals are excluded (see globals.txt and check-c-globals.py).
Error messages when pass keyword arguments to some builtins that
don't support keyword arguments contained double parenthesis: "()()".
The regression was introduced by bpo-30534.
new exception with setting current exception as __cause__.
_PyErr_FormatFromCause(exception, format, args...) is equivalent to Python
raise exception(format % args) from sys.exc_info()[1]
