Fix warnings when using -Wimplicit-fallthrough compiler flag.
Annotate explicitly "fall through" switch cases with a new
_Py_FALLTHROUGH macro which uses __attribute__((fallthrough)) if
available. Replace "fall through" comments with _Py_FALLTHROUGH.
Add _Py__has_attribute() macro. No longer define __has_attribute()
macro if it's not defined. Move also _Py__has_builtin() at the top
of pyport.h.
Co-Authored-By: Nikita Sobolev <mail@sobolevn.me>
The `__has_feature(thread_sanitizer)` is a Clang-ism. Although new
versions of GCC implement `__has_feature`, the `defined(__has_feature)`
check still fails on GCC so we don't use that code path.
Change the declaration of the keywords parameter in functions
PyArg_ParseTupleAndKeywords() and PyArg_VaParseTupleAndKeywords() from `char **`
to `char * const *` in C and `const char * const *` in C++.
It makes these functions compatible with argument of type `const char * const *`,
`const char **` or `char * const *` in C++ and `char * const *` in C
without explicit type cast.
Co-authored-by: C.A.M. Gerlach <CAM.Gerlach@Gerlach.CAM>
This adds a macro `Py_CAN_START_THREADS` that corresponds to the Python
function `test.support.threading_helper.can_start_thread()`. WASI and
some Emscripten builds do not have a working pthread implementation.
This macro is used to guard the critical sections C API tests that
require a working threads implementation.
If the Py_LIMITED_API macro is defined, Py_BUILD_CORE,
Py_BUILD_CORE_BUILTIN and Py_BUILD_CORE_MODULE macros are now
undefined by Python.h.
Only undefine these 3 macros after including "exports.h" which uses
them to define PyAPI_FUNC(), PyAPI_DATA() and PyMODINIT_FUNC macros.
Remove hacks (undefine manually the 3 Py_BUILD_CORE macros) in
Modules/_testcapi/parts.h and Modules/_testclinic_limited.c.
Remove <ctype.h> in C files which don't use it; only sre.c and
_decimal.c still use it.
Remove _PY_PORT_CTYPE_UTF8_ISSUE code from pyport.h:
* Code added by commit b5047fd019
in 2004 for MacOSX and FreeBSD.
* Test removed by commit 52ddaefb6b
in 2007, since Python str type now uses locale independent
functions like Py_ISALPHA() and Py_TOLOWER() and the Unicode
database.
Modules/_sre/sre.c replaces _PY_PORT_CTYPE_UTF8_ISSUE with new
functions: sre_isalnum(), sre_tolower(), sre_toupper().
Remove unused includes:
* _localemodule.c: remove <stdio.h>.
* getargs.c: remove <float.h>.
* dynload_win.c: remove <direct.h>, it no longer calls _getcwd()
since commit fb1f68ed7c (in 2001).
Python.h no longer includes <time.h>, <sys/select.h> and <sys/time.h>
standard header files.
* Add <time.h> include to xxsubtype.c.
* Add <sys/time.h> include to posixmodule.c and semaphore.c.
* readline.c includes <sys/select.h> instead of <sys/time.h>.
* resource.c no longer includes <time.h> and <sys/time.h>.
Move prototypes of gethostname(), _getpty() and struct termios from
pyport.h to the C code using them: posixmodule.c, socketmodule.c and
termios.c.
Replace "#ifdef SOLARIS" with "#ifdef __sun".
* Move <ctype.h>, <limits.h> and <stdarg.h> standard includes to
Python.h.
* Move "pystats.h" include from object.h to Python.h.
* Remove redundant "pymem.h" include in objimpl.h and "pyport.h"
include in pymem.h; Python.h already includes them earlier.
* Remove redundant <wchar.h> include in unicodeobject.h; Python.h
already includes it.
* Move _SGI_MP_SOURCE define from Python.h to pyport.h.
* pycore_condvar.h includes explicitly <unistd.h> for the
_POSIX_THREADS macro.
Python built with "configure --with-trace-refs" (tracing references)
is now ABI compatible with Python release build and debug build.
Moreover, it now also supports the Limited API.
Change Py_TRACE_REFS build:
* Remove _PyObject_EXTRA_INIT macro.
* The PyObject structure no longer has two extra members (_ob_prev
and _ob_next).
* Use a hash table (_Py_hashtable_t) to trace references (all
objects): PyInterpreterState.object_state.refchain.
* Py_TRACE_REFS build is now ABI compatible with release build and
debug build.
* Limited C API extensions can now be built with Py_TRACE_REFS:
xxlimited, xxlimited_35, _testclinic_limited.
* No longer rename PyModule_Create2() and PyModule_FromDefAndSpec2()
functions to PyModule_Create2TraceRefs() and
PyModule_FromDefAndSpec2TraceRefs().
* _Py_PrintReferenceAddresses() is now called before
finalize_interp_delete() which deletes the refchain hash table.
* test_tracemalloc find_trace() now also filters by size to ignore
the memory allocated by _PyRefchain_Trace().
Test changes for Py_TRACE_REFS:
* Add test.support.Py_TRACE_REFS constant.
* Add test_sys.test_getobjects() to test sys.getobjects() function.
* test_exceptions skips test_recursion_normalizing_with_no_memory()
and test_memory_error_in_PyErr_PrintEx() if Python is built with
Py_TRACE_REFS.
* test_repl skips test_no_memory().
* test_capi skisp test_set_nomemory().
We replace _PyRuntime.tstate_current with a thread-local variable. As part of this change, we add a _Py_thread_local macro in pyport.h (only for the core runtime) to smooth out the compiler differences. The main motivation here is in support of a per-interpreter GIL, but this change also provides some performance improvement opportunities.
Note that we do not provide a fallback to the thread-local, either falling back to the old tstate_current or to thread-specific storage (PyThread_tss_*()). If that proves problematic then we can circle back. I consider it unlikely, but will run the buildbots to double-check.
Also note that this does not change any of the code related to the GILState API, where it uses a thread state stored in thread-specific storage. I suspect we can combine that with _Py_tss_tstate (from here). However, that can be addressed separately and is not urgent (nor critical).
(While this change was mostly done independently, I did take some inspiration from earlier (~2020) work by @markshannon (main...markshannon:threadstate_in_tls) and @vstinner (#23976).)
This is the implementation of PEP683
Motivation:
The PR introduces the ability to immortalize instances in CPython which bypasses reference counting. Tagging objects as immortal allows up to skip certain operations when we know that the object will be around for the entire execution of the runtime.
Note that this by itself will bring a performance regression to the runtime due to the extra reference count checks. However, this brings the ability of having truly immutable objects that are useful in other contexts such as immutable data sharing between sub-interpreters.
The Py_CLEAR(), Py_SETREF() and Py_XSETREF() macros now only evaluate
their arguments once. If an argument has side effects, these side
effects are no longer duplicated.
Use temporary variables to avoid duplicating side effects of macro
arguments. If available, use _Py_TYPEOF() to avoid type punning.
Otherwise, use memcpy() for the assignment to prevent a
miscompilation with strict aliasing caused by type punning.
Add _Py_TYPEOF() macro: __typeof__() on GCC and clang.
Add test_py_clear() and test_py_setref() unit tests to _testcapi.
Add C++ overloads for _Py_CAST_impl() to handle 0/NULL. This will allow
C++ extensions that pass 0 or NULL to macros using _Py_CAST() to
continue to compile. Without this, you get an error like:
invalid ‘static_cast’ from type ‘int’ to type ‘_object*’
The modern way to use a NULL value in C++ is to use nullptr. However,
we want to not break extensions that do things the old way.
Co-authored-by: serge-sans-paille
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 C++ compiler warnings: "zero as null pointer constant"
(clang -Wzero-as-null-pointer-constant).
* Add the _Py_NULL macro used by static inline functions to use
nullptr in C++.
* Replace NULL with nullptr in _testcppext.cpp.
Fix C++ compiler warnings on cast macros, like _PyObject_CAST(), when
casting a constant expression to a non constant type: use
const_cast<> in C++.
* In C++, Py_SAFE_DOWNCAST() now uses static_cast<> rather than
reinterpret_cast<>.
* Add tests to the _testcppext C++ extension.
* test_cppext no longer captures stdout in verbose mode.
Fix C++ compiler warnings about "old-style cast"
(g++ -Wold-style-cast) in the Python C API. Use C++
reinterpret_cast<> and static_cast<> casts when the Python C API is
used in C++.
Example of fixed warning:
Include/object.h:107:43: error: use of old-style cast to
‘PyObject*’ {aka ‘struct _object*’} [-Werror=old-style-cast]
#define _PyObject_CAST(op) ((PyObject*)(op))
Add _Py_reinterpret_cast() and _Py_static_cast() macros.
Remove the HAVE_PY_SET_53BIT_PRECISION macro (moved to the internal
C API).
* Move HAVE_PY_SET_53BIT_PRECISION macro to pycore_pymath.h.
* Replace PY_NO_SHORT_FLOAT_REPR macro with _PY_SHORT_FLOAT_REPR
macro which is always defined. gcc -Wundef emits a warning when
using _PY_SHORT_FLOAT_REPR but the macro is not defined, if
pycore_pymath.h include was forgotten.
The Python 3.11 limited C API no longer includes stdlib.h, stdio.h,
string.h and errno.h.
* Exclude Py_MEMCPY() from Python 3.11 limited C API.
* xxlimited C extension is now built with Python 3.11 limited C API.
Move the following macros , to pycore_pymath.h (internal C API):
* _Py_SET_53BIT_PRECISION_HEADER
* _Py_SET_53BIT_PRECISION_START
* _Py_SET_53BIT_PRECISION_END
PEP 7: add braces to if and "do { ... } while (0)" in these macros.
Move also _Py_get_387controlword() and _Py_set_387controlword()
definitions to pycore_pymath.h. These functions are no longer
exported.
pystrtod.c now includes pycore_pymath.h.
* Move limits.h include and UCHAR_MAX checks to pyport.h.
* Move sanitizers macros to pyport.h.
* Remove comment about <assert.h>: C extensions are built with NDEBUG
automatically by Python.
Remove the following math macros using the errno variable:
* Py_ADJUST_ERANGE1()
* Py_ADJUST_ERANGE2()
* Py_OVERFLOWED()
* Py_SET_ERANGE_IF_OVERFLOW()
* Py_SET_ERRNO_ON_MATH_ERROR()
Create pycore_pymath.h internal header file.
Rename Py_ADJUST_ERANGE1() and Py_ADJUST_ERANGE2() to
_Py_ADJUST_ERANGE1() and _Py_ADJUST_ERANGE2(), and convert these
macros to static inline functions.
Move the following macros to pycore_pymath.h:
* _Py_IntegralTypeSigned()
* _Py_IntegralTypeMax()
* _Py_IntegralTypeMin()
* _Py_InIntegralTypeRange()
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.
Victor Stinner
Sam Gross
Samet YASLAN
Serhiy Storchaka
Petr Viktorin
Eric Snow
Eddie Elizondo
Michael Droettboom
Ayappan Perumal
Neil Schemenauer
serge-sans-paille
Ganesh Kathiresan
neonene
Mark Dickinson
Christian Heimes
Inada Naoki