Unconditional forcing of ``CHECKED_HASH`` invalidation was introduced in
3.7.0 in bpo-29708. The change is bad, as it unconditionally overrides
*invalidation_mode*, even if it was passed as an explicit argument to
``py_compile.compile()`` or ``compileall``. An environment variable
should *never* override an explicit argument to a library function.
That change leads to multiple test failures if the ``SOURCE_DATE_EPOCH``
environment variable is set.
This changes ``py_compile.compile()`` to only look at
``SOURCE_DATE_EPOCH`` if no explicit *invalidation_mode* was specified.
I also made various relevant tests run with explicit control over the
value of ``SOURCE_DATE_EPOCH``.
While looking at this, I noticed that ``zipimport`` does not work
with hash-based .pycs _at all_, though I left the fixes for
subsequent commits.
In some development setups it is inconvenient or impossible to write bytecode
caches to the code tree, but the bytecode caches are still useful. The
PYTHONPYCACHEPREFIX environment variable allows specifying an alternate
location for cached bytecode files, within which a directory tree mirroring the code
tree will be created. This cache tree is then used (for both reading and writing)
instead of the local `__pycache__` subdirectory within each source directory.
Exposed at runtime as sys.pycache_prefix (defaulting to None), and can
be set from the CLI as "-X pycache_prefix=path".
Patch by Carl Meyer.
Multi-phase initialized modules allow m_traverse to be called while the
module is still being initialized, so module authors may need to account
for that.
* Fix multiple typos in code comments
* Add spacing in comments (test_logging.py, test_math.py)
* Fix spaces at the beginning of comments in test_logging.py
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.
Previously AttributeError was raised, but that's not very reflective of the fact that the requested module can't be found since the specified parent isn't actually a package.
* bpo-29514: Check magic number for micro release
Add a dict importlib.util.EXPECTED_MAGIC_NUMBERS which
details the initial and expected pyc magic number for
each minor release. This gives a mechanism for users to
check if the magic number has changed within a release and
for a test to ensure procedure is followed if a change is
necessary.
Add a test to check the current MAGIC_NUMBER against the
expected number for the release if the current release is
at candidate or final level. On test failure, describe to
the developer the procedure for changing the magic number.
* Simplify magic number release test
Simplify the magic number release test by removing
EXPECTED_MAGIC_NUMBERS table and making the expected
magic number self-contained within the test.
BPO: 29514
* Improve magic number test execution and message
Improve the execution of the magic number test by
using skipUnless for alpha and beta releases, and
directly inheriting from unittest.TestCase rather than
using the machinery for the other tests. Also improve
the error message to explain the reason for caution in
changing the magic number.
BPO: 29514
Multi-phase extension module import now correctly allows the
``m_methods`` field to be used to add module level functions
to instances of non-module types returned from ``Py_create_mod``.
Patch by Xiang Zhang.
Windows.
Originally only b'PYTHONCASEOK' was being checked for in os.environ,
but that won't work under Windows where all environment variables are
strings (on OS X they are bytes).
Thanks to Eryk Sun for the bug report.
modules can't be lazily loaded.
Thanks to Python 3.6 allowing for types.ModuleType to have its
__class__ mutated, the restriction can be lifted by calling
create_module() on the wrapped loader.