The implementation of weakref.proxy's methods call back into the Python
API using a borrowed references of the weakly referenced object
(acquired via PyWeakref_GET_OBJECT). This API call may delete the last
reference to the object (either directly or via GC), leaving a dangling
pointer, which can be subsequently dereferenced.
To fix this, claim a temporary ownership of the referenced object when
calling the appropriate method. Some functions because at the moment they
do not need to access the borrowed referent, but to protect against
future changes to these functions, ownership need to be fixed in
all potentially affected methods..
(cherry picked from commit 10cd00a9e3)
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
Don't pass complex expressions but regular variables to Python
macros.
* _datetimemodule.c: split single large "if" into two "if"
in date_new(), time_new() and datetime_new().
* _pickle.c, load_extension(): flatten complex "if" expression into
more regular C code.
* _ssl.c: addbool() now uses a temporary bool_obj to only evaluate
the value once.
* weakrefobject.c: replace "Py_INCREF(result = proxy);"
with "result = proxy; Py_INCREF(result);"
METH_NOARGS functions need only a single argument but they are cast
into a PyCFunction, which takes two arguments. This triggers an
invalid function cast warning in gcc8 due to the argument mismatch.
Fix this by adding a dummy unused argument.
Error messages when pass keyword arguments to some builtins that
don't support keyword arguments contained double parenthesis: "()()".
The regression was introduced by bpo-30534.
Issue #28858: The change b9c9691c72c5 introduced a regression. It seems like
_PyObject_CallArg1() uses more stack memory than
PyObject_CallFunctionObjArgs().
* PyObject_CallFunctionObjArgs(func, NULL) => _PyObject_CallNoArg(func)
* PyObject_CallFunctionObjArgs(func, arg, NULL) => _PyObject_CallArg1(func, arg)
PyObject_CallFunctionObjArgs() allocates 40 bytes on the C stack and requires
extra work to "parse" C arguments to build a C array of PyObject*.
_PyObject_CallNoArg() and _PyObject_CallArg1() are simpler and don't allocate
memory on the C stack.
This change is part of the fastcall project. The change on listsort() is
related to the issue #23507.
