gh-124621: Emscripten: Support pyrepl in browser (GH-136931)
Basic support for pyrepl in Emscripten. Limitations:
* requires JSPI
* no signal handling implemented
As followup work, it would be nice to implement a webworker variant
for when JSPI is not available and proper signal handling.
Because it requires JSPI, it doesn't work in Safari. Firefox requires
setting an experimental flag. All the Chromiums have full support since
May. Until we make it work without JSPI, let's keep the original web_example
around.
Dave Peck [Tue, 22 Jul 2025 09:44:13 +0000 (02:44 -0700)]
gh-132661: Document t-strings and `templatelib` (#135229)
Co-authored-by: Petr Viktorin <encukou@gmail.com> Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com> Co-authored-by: Loïc Simon <loic.pano@gmail.com> Co-authored-by: pauleveritt <pauleveritt@me.com>
Malcolm Smith [Tue, 22 Jul 2025 06:51:16 +0000 (07:51 +0100)]
gh-131531: Android test fixes (#136845)
Modifies the test runner script to no longer export the the HOST environment
variable, and to allow for tests that produce no Python output (output from the
Android console is still expected and required). These changes stem from
knowledge gained during developing a PR for Android support in cibuildwheel.
gh-135228: When @dataclass(slots=True) replaces a dataclass, make the original class collectible (#136893)
An interesting hack, but more localized in scope than #135230.
This may be a breaking change if people intentionally keep the original class around
when using `@dataclass(slots=True)`, and then use `__dict__` or `__weakref__` on the
original class.
The macros are identical to the corresponding `Py_BEGIN_CRITICAL_SECTION` and
`Py_BEGIN_CRITICAL_SECTION2` macros (e.g., they include braces), but they
accept a `PyMutex` instead of an object.
The new macros are still paired with the existing END macros
(`Py_END_CRITICAL_SECTION`, `Py_END_CRITICAL_SECTION2`).
gh-136870: fix data race in `PyThreadState_Clear` on `sys_tracing_threads` (#136951)
In free-threading, multiple threads can be cleared concurrently as such the modifications on `sys_tracing_threads` should be done while holding the profile lock, otherwise it can race with other threads setting up profiling.
Peter Bierma [Mon, 21 Jul 2025 17:47:26 +0000 (12:47 -0500)]
gh-136421: Load `_datetime` static types during interpreter initialization (GH-136583)
`_datetime` is a special module, because it's the only non-builtin C extension that contains static types. As such, it would initialize static types in the module's execution function, which can run concurrently. Since static type initialization is not thread-safe, this caused crashes. This fixes it by moving the initialization of `_datetime`'s static types to interpreter startup (where all other static types are initialized), which is already properly protected through other locks.
gh-116738: Make syslog module thread-safe (#136760)
Make the setlogmask() function in the syslog module thread-safe. These changes are relevant for scenarios where the GIL is disabled or when using subinterpreters.
gh-136438: Make sure `test_generated_cases` pass with all optimization levels (#136594)
Fix the `test_generated_cases` to work with `-O` or `-OO` flags.
Previously, `test_generated_cases` was catching an `AssertionError` while `Tools/cases_generator/optimizer_generator.py` used an `assert` statement. This approach semantically incorrect, no one should trying to catch an `AssertionError`!
Now the `assert` statement has been replaced with an explicit `raise ValueError(...)` and the corresponding `self.assertRaisesRegex(AssertionError, ...)` has been updated to catch a `ValueError` instead.
gh-134411: assert `PyLong_FromLong(x) != NULL` when `x` is known to be small (#134415)
Since `PyLong_From Long(PY_MONITORING_DEBUGGER_ID)` falls to `small_int` case and can't return `NULL`. Added `assert`s for extra confidence.
https://github.com/python/cpython/issues/134411#issuecomment-2897653868
UUIDv8 has been added in Python 3.14.0a2 and its construction time
has been improved in Python 3.14.0a4, but since those changes will
not be visible when comparing the latest Python 3.13 and 3.14 together,
we do not document them on the What's New page to avoid confusion.
GH-130645: Default to color help in argparse (#136809)
Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com> Co-authored-by: Łukasz Langa <lukasz@langa.pl> Co-authored-by: Adam Turner <9087854+aa-turner@users.noreply.github.com>
gh-134531: prefer using `_hashlib` module state instead of module object (#136865)
Some internal helper functions taking the module object to retrieve its state
under some conditions now directly take the module's state instead as those
conditions hold most of the time.
gh-136547: fix `hashlib_helper` for blocking and requesting digests (#136762)
- Fix `hashlib_helper.block_algorithm` where the dummy functions were incorrectly defined.
- Rename `hashlib_helper.HashAPI` to `hashlib_helper.HashInfo` and add more helper methods.
- Simplify `hashlib_helper.requires_*()` functions.
- Rewrite some private helpers in `hashlib_helper`.
- Remove `find_{builtin,openssl}_hashdigest_constructor()` as they are no more needed and were
not meant to be public in the first place.
- Fix some tests in `test_hashlib` when FIPS mode is on.
gh-124621: Emscripten: Add support for async input devices (GH-136822)
This is useful for implementing proper `input()`. It requires the
JavaScript engine to support the wasm JSPI spec which is now stage 4.
It is supported on Chrome since version 137 and on Firefox and node
behind a flag.
We override the `__wasi_fd_read()` syscall with our own variant that
checks for a readAsync operation. If it has it, we use our own async
variant of `fd_read()`, otherwise we use the original `fd_read()`.
We also add a variant of `FS.createDevice()` called
`FS.createAsyncInputDevice()`.
Finally, if JSPI is available, we wrap the `main()` symbol with
`WebAssembly.promising()` so that we can stack switch from `fd_read()`.
If JSPI is not available, attempting to read from an AsyncInputDevice
will raise an `OSError`.
Doc/c-api/memory.rst: extend --without-pymalloc doc with ASan information (GH-136790)
* Doc/c-api/memory.rst: extend --without-pymalloc doc with ASan information
This commit extends the documentation for disabling pymalloc with the `--without-pymalloc` flag regarding why it is worth to use it when enabling AddressSanitizer for Python build (which is done, e.g., in CPython's CI builds).
I have tested the CPython latest main build with both ASan and pymalloc enabled and it seems to work just fine. I did run the `python -m test` suite which didn't uncover any ASan crashes (though, it detected some memory leaks, which I believe are irrelevant here).
I have discussed ASan and this flag with @encukou on the CPython Core sprint on EuroPython 2025. We initially thought that the `--without-pymalloc` flag is needed for ASan builds due to the fact pymalloc must hit the begining of page when determining if the memory to be freed comes from pymalloc or was allocated by the system malloc. In other words, we thought, that ASan would crash CPython during free of big objects (allocated by system malloc). It may be that this was the case in the past, but it is not the case anymore as the `address_in_range` function used by pymalloc is annotated to be skipped from the ASan instrumentation.
And the corresponding attribute is documented in:
* for gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-no_005fsanitize_005faddress-function-attribute
* for clang: https://clang.llvm.org/docs/AttributeReference.html#no-sanitize-address-no-address-safety-analysis
* Update Doc/c-api/memory.rst
* Improve --with-address-sanitizer and pymalloc docs
gh-136769: Include fixed-width integers in the fundamental data types table (#136784)
Fixed-sized types, like ``c_int32``, are currently missing from the fundamental data types table
in the ``ctypes`` documentation. This commit adds them, and notes that ``c_[u]int8`` is an alias
of ``c_[u]byte``.
Docs: Improve example for ``itertools.batched()`` (#136775)
The current example `batched('ABCDEFG', n=3) → ABC DEF G` can confuse readers because both, the size of the tuples and the number of tuples are 3.
By using a batch size of n=2, it is clearer that the `n` argument refers to the size of the resulting tuples.
I.e. the new example is: `batched('ABCDEFG', n=2) → AB CD EF G`
gh-136438: Make sure `test_ast` pass with all optimization levels (#136596)
Explicitly pass an `optimizer` parameter to the calls of `ast.parse/compile`, because if it is not provided, the interpreter will use its internal state, which can be modified using the `-O` or `-OO` flags.
Make the pwd module functions getpwuid(), getpwnam(), and getpwall() thread-safe. These changes apply to scenarios where the GIL is disabled or in subinterpreter use cases.
gh-127146: Emscripten: Set umask to zero in python.sh (#136740)
Clears the umask used during a test of pydoc.apropos when testing on
Emscripten. This is to work around a known issue in Emscripten; but it's not
clear if the chmod call that is causing the problem is actually testing
anything of significance.
gh-127146: Emscripten: Make os.umask() actually work (#136706)
Provide a stub implementation of umask that is enough to get some tests passing.
More work is needed upstream in Emscripten to make all umask tests to pass.