"Zero cost" exception handling.
* Uses a lookup table to determine how to handle exceptions.
* Removes SETUP_FINALLY and POP_TOP block instructions, eliminating (most of) the runtime overhead of try statements.
* Reduces the size of the frame object by about 60%.
This works by not caching the handle and instead getting the handle from
the file descriptor each time, so that if the actual handle changes by
fd redirection closing/opening the console handle beneath our feet, we
will keep working correctly.
The inclusion of PyOS_ReadlineFunctionPointer in python3dll.c was a mistake.
According to PEP 384:
> functions expecting FILE* are not part of the ABI, to avoid depending
> on a specific version of the Microsoft C runtime DLL on Windows.
https://bugs.python.org/issue43868
Each section is sorted to reduce diffs (review effort) when the file becomes generated.
Sort is done with key=str.lower to preserve most of the original order (underscored items first).
https://bugs.python.org/issue43795
The limited C API is now supported if Python is built in debug mode
(if the Py_DEBUG macro is defined). In the limited C API, the
Py_INCREF() and Py_DECREF() functions are now implemented as opaque
function calls, rather than accessing directly the PyObject.ob_refcnt
member, if Python is built in debug mode and the Py_LIMITED_API macro
targets Python 3.10 or newer. It became possible to support the
limited C API in debug mode because the PyObject structure is the
same in release and debug mode since Python 3.8 (see bpo-36465).
The limited C API is still not supported in the --with-trace-refs
special build (Py_TRACE_REFS macro).
* Remove m68k-specific hack from ascii_decode
On m68k, alignments of primitives is more relaxed, with 4-byte and
8-byte types only requiring 2-byte alignment, thus using sizeof(size_t)
does not work. Instead, use the portable alternative.
Note that this is a minimal fix that only relaxes the assertion and the
condition for when to use the optimised version remains overly strict.
Such issues will be fixed tree-wide in the next commit.
NB: In C11 we could use _Alignof(size_t) instead, but for compatibility
we use autoconf.
* Optimise string routines for architectures with non-natural alignment
C only requires that sizeof(x) is a multiple of alignof(x), not that the
two are equal. Thus anywhere where we optimise based on alignment we
should be using alignof(x) not sizeof(x).
This is more annoying than it would be in C11 where we could just use
_Alignof(x) (and alignof(x) in C++11), but since we still require only
C99 we must plumb the information all the way from autoconf through the
various typedefs and defines.
See [PEP 597](https://www.python.org/dev/peps/pep-0597/).
* Add `-X warn_default_encoding` and `PYTHONWARNDEFAULTENCODING`.
* Add EncodingWarning
* Add io.text_encoding()
* open(), TextIOWrapper() emits EncodingWarning when encoding is omitted and warn_default_encoding is enabled.
* _pyio.TextIOWrapper() uses UTF-8 as fallback default encoding used when failed to import locale module. (used during building Python)
* bz2, configparser, gzip, lzma, pathlib, tempfile modules use io.text_encoding().
* What's new entry
Rename Include/symtable.h to to Include/internal/pycore_symtable.h,
don't export symbols anymore (replace PyAPI_FUNC and PyAPI_DATA with
extern) and rename functions:
* PyST_GetScope() to _PyST_GetScope()
* PySymtable_BuildObject() to _PySymtable_Build()
* PySymtable_Free() to _PySymtable_Free()
Remove PySymtable_Build(), Py_SymtableString() and
Py_SymtableStringObject() functions.
The Py_SymtableString() function was part the stable ABI by mistake
but it could not be used, since the symtable.h header file was
excluded from the limited C API.
The Python symtable module remains available and is unchanged.
The distutils bdist_wininst command deprecated in Python 3.8 has been
removed. The distutils bidst_wheel command is now recommended to
distribute binary packages on Windows.
* Remove Lib/distutils/command/bdist_wininst.py
* Remove PC/bdist_wininst/ project
* Remove Lib/distutils/command/wininst-*.exe programs
* Remove all references to bdist_wininst
Export the Py_FrozenMain() function: fix a Python 3.9.0 regression.
Python 3.9 uses -fvisibility=hidden and the function was not exported
explicitly and so not exported.
Add also Py_FrozenMain to the stable ABI on Windows.
- Copy existing xxlimited to xxlimited53 (named for the limited API version it uses)
- Build both modules, both in debug and release
- Test both modules
No longer use deprecated aliases to functions:
* Replace PyObject_MALLOC() with PyObject_Malloc()
* Replace PyObject_REALLOC() with PyObject_Realloc()
* Replace PyObject_FREE() with PyObject_Free()
* Replace PyObject_Del() with PyObject_Free()
* Replace PyObject_DEL() with PyObject_Free()
No longer use deprecated aliases to functions:
* Replace PyMem_MALLOC() with PyMem_Malloc()
* Replace PyMem_REALLOC() with PyMem_Realloc()
* Replace PyMem_FREE() with PyMem_Free()
* Replace PyMem_Del() with PyMem_Free()
* Replace PyMem_DEL() with PyMem_Free()
Modify also the PyMem_DEL() macro to use directly PyMem_Free().
It was moved out of the limited API in 7d95e40721.
This change re-enables it from 3.10, to avoid generating invalid extension modules for earlier versions.
Remove the global _Py_CheckRecursionLimit variable: it has been
replaced by ceval.recursion_limit of the PyInterpreterState
structure.
There is no need to keep the variable for the stable ABI, since
Py_EnterRecursiveCall() and Py_LeaveRecursiveCall() were not usable
in Python 3.8 and older: these macros accessed PyThreadState members,
whereas the PyThreadState structure is opaque in the limited C API.
Mark Shannon
Petr Viktorin
Pablo Galindo
Segev Finer
Victor Stinner
Jessica Clarke
Zackery Spytz
Inada Naoki
Antoine Pitrou
Jozef Grajciar
Ikko Ashimine
Ken Jin
Dong-hee Na
Steve Dower
Alex Gaynor
Vladimir Matveev
Terry Jan Reedy
Serhiy Storchaka