Add the Py_ALWAYS_INLINE macro to ask the compiler to always inline a
static inline function. The compiler can ignore it and decides to not
inline the function.
As part of the PEP-652 implementation, I'll tighten the CI check
for functions/data defined with `Py_LIMITED_API`.
Discussion in https://discuss.python.org/t/pep-652-maintaining-the-stable-abi/6986
suggests that parsing C headers is OK (though personally I'd rather generate it...),
but writing a full C parser is a monumental task and adding an existing one as a
dependency brings too many vendoring/bootstraping issues.
So, for the check I'll use a "simple" regex on preprocessor output, and adapt
the few trivial places where the regex won't work.
- Keep declarations in the limited API to one item per line
- Make it possible to override `_Py_NO_RETURN`, so the annotation can be
removed from preprocessor output.
https://bugs.python.org/issue43795
Fix building pycore_bitutils.h internal header on old clang version
without __builtin_bswap16() (ex: Xcode 4.6.3 on Mac OS X 10.7).
Add a new private _Py__has_builtin() macro to check for availability
of a preprocessor builtin function.
Co-Authored-By: Joshua Root <jmr@macports.org>
Co-authored-by: Joshua Root <jmr@macports.org>
If the nl_langinfo(CODESET) function returns an empty string, Python
now uses UTF-8 as the filesystem encoding.
In May 2010 (commit b744ba1d14), I
modified Python to log a warning and use UTF-8 as the filesystem
encoding (instead of None) if nl_langinfo(CODESET) returns an empty
string.
In August 2020 (commit 94908bbc15), I
modified Python startup to fail with a fatal error and a specific
error message if nl_langinfo(CODESET) returns an empty string. The
intent was to prevent guessing the encoding and also investigate user
configuration where this case happens.
In 10 years (2010 to 2020), I saw zero user report about the error
message related to nl_langinfo(CODESET) returning an empty string.
Today, UTF-8 became the defacto standard and it's safe to make the
assumption that the user expects UTF-8. For example,
nl_langinfo(CODESET) can return an empty string on macOS if the
LC_CTYPE locale is not supported, and UTF-8 is the default encoding
on macOS.
While this change is likely to not affect anyone in practice, it
should make UTF-8 lover happy ;-)
Rewrite also the documentation explaining how Python selects the
filesystem encoding and error handler.
The PEP 353, written in 2005, introduced PY_FORMAT_SIZE_T. Python no
longer supports macOS 10.4 and Visual Studio 2010, but requires more
recent macOS and Visual Studio versions. In 2020 with Python 3.10, it
is now safe to use directly "%zu" to format size_t and "%zi" to
format Py_ssize_t.
Add a new internal pycore_byteswap.h header file with the following
functions:
* _Py_bswap16()
* _Py_bswap32()
* _Py_bswap64()
Use these functions in _ctypes, sha256 and sha512 modules,
and also use in the UTF-32 encoder.
sha256, sha512 and _ctypes modules are now built with the internal
C API.
Add _Py_FORCE_UTF8_LOCALE and _Py_FORCE_UTF8_FS_ENCODING macros to
avoid factorize "#if defined(__ANDROID__) || defined(__VXWORKS__)"
and "#if defined(__APPLE__)".
Cleanup also config_init_fs_encoding().
Change PyAPI_FUNC(type), PyAPI_DATA(type) and PyMODINIT_FUNC macros
of pyport.h when Py_BUILD_CORE_MODULE is defined.
The Py_BUILD_CORE_MODULE define must be now be used to build a C
extension as a dynamic library accessing Python internals: export the
PyInit_xxx() function in DLL exports on Windows.
Changes:
* Py_BUILD_CORE_BUILTIN and Py_BUILD_CORE_MODULE now imply
Py_BUILD_CORE directy in pyport.h.
* ceval.c compilation now fails with an error if Py_BUILD_CORE is not
defined, just to ensure that Python is build with the correct
defines.
* setup.py now compiles _pickle.c with Py_BUILD_CORE_MODULE define.
* setup.py compiles _json.c with Py_BUILD_CORE_MODULE define, rather
than Py_BUILD_CORE_BUILTIN define
* PCbuild/pythoncore.vcxproj: Add Py_BUILD_CORE_BUILTIN define.
* Disable x87 control word for non-x86 targets
On msvc, x87 control word is only available on x86 target. Need to disable it for other targets to prevent compiling problems.
* Include immintrin.h on x86 and x64 only
Immintrin.h is only available on x86 and x64. Need to disable it for other targets to prevent compiling problems.
* Add Py_STATIC_INLINE() macro to declare a "static inline" function.
If the compiler supports it, try to always inline the function even if no
optimization level was specified.
* Modify pydtrace.h to use Py_STATIC_INLINE() when WITH_DTRACE is
not defined.
* Add an unit test on Py_DECREF() to make sure that
_Py_NegativeRefcount() reports the correct filename.
Fix the pthread+semaphore implementation of
PyThread_acquire_lock_timed() when called with timeout > 0 and
intr_flag=0: recompute the timeout if sem_timedwait() is interrupted
by a signal (EINTR).
See also the PEP 475.
The pthread implementation of PyThread_acquire_lock() now fails with
a fatal error if the timeout is larger than PY_TIMEOUT_MAX, as done
in the Windows implementation.
The check prevents any risk of overflow in PyThread_acquire_lock().
Add also PY_DWORD_MAX constant.
Issue #29234: Inlining _PyStack_AsTuple() into callers increases their stack
consumption, Disable inlining to optimize the stack consumption.
Add _Py_NO_INLINE: use __attribute__((noinline)) of GCC and Clang.
It reduces the stack consumption, bytes per call, before => after:
test_python_call: 1040 => 976 (-64 B)
test_python_getitem: 976 => 912 (-64 B)
test_python_iterator: 1120 => 1056 (-64 B)
=> total: 3136 => 2944 (- 192 B)
When Python is not compiled with PGO, the performance of Python on call_simple
and call_method microbenchmarks depend highly on the code placement. In the
worst case, the performance slowdown can be up to 70%.
The GCC __attribute__((hot)) attribute helps to keep hot code close to reduce
the risk of such major slowdown. This attribute is ignored when Python is
compiled with PGO.
The following functions are considered as hot according to statistics collected
by perf record/perf report:
* _PyEval_EvalFrameDefault()
* call_function()
* _PyFunction_FastCall()
* PyFrame_New()
* frame_dealloc()
* PyErr_Occurred()
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