Fix initialization of Python-3.8--only at-end tp_print member

Until Python 3.7, PyTypeObject had a member tp_print following tp_dealloc, which
had then been repurposed as

>      /* Methods to implement standard operations */
>
>      destructor tp_dealloc;
> -    printfunc tp_print;
> +    Py_ssize_t tp_vectorcall_offset;
>      getattrfunc tp_getattr;
>      setattrfunc tp_setattr;
>      PyAsyncMethods *tp_as_async; /* formerly known as tp_compare (Python 2)

in <https://github.com/python/cpython/commit/
aacc77fbd77640a8f03638216fa09372cc21673d> "bpo-36974: implement PEP 590
(GH-13185)" towards Python 3.8.  Then only on the 3.8 branch (and prior to tag
v3.8.0), <https://github.com/python/cpython/commit/
d917cfe4051d45b2b755c726c096ecfcc4869ceb> "[3.8] bpo-37250: put back tp_print
for backwards compatibility (GH-14193)" added

>      destructor tp_finalize;
>      vectorcallfunc tp_vectorcall;
>
> +    /* bpo-37250: kept for backwards compatibility in CPython 3.8 only */
> +    Py_DEPRECATED(3.8) int (*tp_print)(PyObject *, FILE *, int);
> +
>  #ifdef COUNT_ALLOCS
>      /* these must be last and never explicitly initialized */
>      Py_ssize_t tp_allocs;

at the end of PyTypeObject.  This was apparently done so that third-party code
containing initialization code like

X.tp_print = 0;

would continue to compile (by just adding back a member with that name, even if
at a "random" new---and otherwise unused---location).  However, for our way of
list-initializing PyTypeObject instances in pyuno that new member caused
"missing field 'tp_print' initializer" -Wmissing-field-initializers warnings, so
50ccb7e82b7053306721cbe220323be072306a29 "python 3.8.2 compile: add tp_print to
PyTypeObject" added initializers for this new at-end member.  But it did so in a
way that raises three concerns:

1  The new member was already added in Python 3.8.0 (prior to tag v3.8.0), not
only in 3.8.2.

2  The new member was only added to Python 3.8.  It has not been added to
current master towards 3.9.

3  It is unclear why the comments mention "Py_ssize_t" as the type of that new
member, when actually it is of a function pointer type (see above).  Probably
best to just drop that from the comments, to avoid confusion.

Change-Id: Ib44f43befd5f28d4c1ac1e9e14bd55bfb4473507
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/94019
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/pyuno/source/module/pyuno_struct.cxx b/pyuno/source/module/pyuno_struct.cxx
index 7696a231f24a..a5b127dc23c6 100644
--- a/pyuno/source/module/pyuno_struct.cxx
+++ b/pyuno/source/module/pyuno_struct.cxx
@@ -347,12 +347,12 @@ static PyTypeObject PyUNOStructType =
     , nullptr
 #if PY_VERSION_HEX >= 0x03080000
     , nullptr // vectorcallfunc tp_vectorcall
-#if PY_VERSION_HEX >= 0x03080200
+#if PY_VERSION_HEX < 0x03090000
 #if defined __clang__
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
 #endif
-    , nullptr //Py_ssize_t tp_print
+    , nullptr // tp_print
 #if defined __clang__
 #pragma clang diagnostic pop
 #endif