This is a rework of #5774 on current main. I was a bit more
conservative in making changes than the original PR.
See @csabella's comments on issue #77024 and the discussion
on #5774 for explanations of several of the changes.
Co-authored-by: Cheryl Sabella <cheryl.sabella@gmail.com>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Added a new stable API function ``PyType_FromMetaclass``, which mirrors
the behavior of ``PyType_FromModuleAndSpec`` except that it takes an
additional metaclass argument. This is, e.g., useful for language
binding tools that need to store additional information in the type
object.
Avoid _PyCodec_Lookup() and PyCodec_LookupError() for most common
built-in encodings and error handlers to avoid creating a temporary
Unicode string object, whereas these encodings and error handlers are
known to be valid.
* ``sys.executable`` is not set
* WASI does not support subprocess
* ``pwd`` module is not available
* WASI checks ``open`` syscall flags more strict, needs r, w, rw flag.
* ``umask`` is not available
* ``/dev/null`` may not be accessible
Python now always use the ``%zu`` and ``%zd`` printf formats to
format a size_t or Py_ssize_t number. Building Python 3.12 requires a
C11 compiler, so these printf formats are now always supported.
* PyObject_Print() and _PyObject_Dump() now use the printf %zd format
to display an object reference count.
* Update PY_FORMAT_SIZE_T comment.
* Remove outdated notes about the %zd format in PyBytes_FromFormat()
and PyUnicode_FromFormat() documentations.
* configure no longer checks for the %zd format and no longer defines
PY_FORMAT_SIZE_T macro in pyconfig.h.
* pymacconfig.h no longer undefines PY_FORMAT_SIZE_T: macOS 10.4 is
no longer supported. Python 3.12 now requires macOS 10.6 (Snow
Leopard) or newer.
Fix __lltrace__ debug feature if the stdout encoding is not UTF-8.
If the stdout encoding is not UTF-8, the first call to
lltrace_resume_frame() indirectly sets lltrace to 0 when calling
unicode_check_encoding_errors() which calls
encodings.search_function().
`EnumType` attempts to create a custom docstring for each enum/flag, but that was failing with pathological flags that had no members (only multi-bit aliases).
The Py_DecodeLocale() and Py_EncodeLocale() now use
_PyRuntime.preconfig, rather than Py_UTF8Mode and
Py_LegacyWindowsFSEncodingFlag global configuration varibles, to
decide if the UTF-8 encoding is used or not.
As documented, these functions must not be called before Python is
preinitialized. The new PyConfig API should now be used, rather than
using deprecated functions like Py_SetPath() or PySys_SetArgv().
Generally comparable perf for the "good" case where memchr doesn't
return any collisions (false matches on lower byte) but clearly faster
with collisions.
Also while there, clarify a few things about why we reduce the hash to 32 bits.
Co-authored-by: Eli Libman <eli@hyro.ai>
Co-authored-by: Yury Selivanov <yury@edgedb.com>
Co-authored-by: Łukasz Langa <lukasz@langa.pl>