Add compatibility to Py_T_*

[rruuaanng]

Hello Python team, I believe we have met countless times in the main repository.

When I port libfdt to Python, I noticed the Py_T_* series of macros, which are only available after version 3.12. Prior to this, the T_* series was used. Can we add compatibility for these basic constants in a compatibility layer, so they are always defined as Py_T_* in supported versions?

If they are defined elsewhere, please point out my mistakes. Thank you, everyone :)

From my repo

#if PY_VERSION_HEX >= 0x03120000
# include <descrobject.h>
#endif

#if PY_VERSION_HEX >= 0x03090000 && PY_VERSION_HEX < 0x03120000
# include <structmember.h>
/** member type */
# ifndef Py_T_UINT
#  define Py_T_UINT T_UINT
# endif
# ifndef Py_T_INT
#  define Py_T_INT T_INT
# endif
/** flags */
# ifndef Py_READONLY
#  define Py_READONLY READONLY
# endif
#endif

(If the request is granted, I hope to complete this historic moment.)

[vstinner]

#if PY_VERSION_HEX >= 0x03090000

Why do you test for Python 3.9?

#ifndef Py_T_UINT

The PY_VERSION_HEX < 0x03120000 test should be enough, no? Why repeating the check for each macro?

[rruuaanng]

Why do you test for Python 3.9?

I didn't really investigate which version they came from. Maybe I'll look for them later.

The PY_VERSION_HEX < 0x03120000 test should be enough, no? Why repeating the check for each macro?

Right. But I don't know what happened, sometimes it appears to be redefined.

For this issue, WDYT?

Edit

e.g.

E:\code\github\pydt\pydt\_pydt\pydt.h(15): warning C4005: "Py_T_UINT": macro redefinition
E:\Anaconda3\include\descrobject.h(66): note: see previous definition of "Py_T_UINT"
E:\code\github\pydt\pydt\_pydt\pydt.h(18): warning C4005: "Py_T_INT": macro redefinition
E:\Anaconda3\include\descrobject.h(54): note: see previous definition of "Py_T_INT"
E:\code\github\pydt\pydt\_pydt\pydt.h(22): warning C4005: "Py_READONLY": macro redefinition
E:\Anaconda3\include\descrobject.h(83): note: see previous definition of "Py_READONLY"

my change

#if PY_VERSION_HEX < 0x03120000
# include <structmember.h>
/** member type */
#  define Py_T_UINT T_UINT
#  define Py_T_INT T_INT
/** flags */
#  define Py_READONLY READONLY
#endif

[rruuaanng]

But it is redefined on the premise that I change my current python version. But I hope it can be built successfully in most versions.
(I used 3.9, but not, I use 3.12)

[vstinner]

Right. But I don't know what happened, sometimes it appears to be redefined.

On which Python version?

[rruuaanng]

My current version it is Python 3.12.7, Maybe it can be other(e.g. 3.9 the first time this error occurred, I abandoned it.)? I don't know :(

[vstinner]

#if PY_VERSION_HEX >= 0x03120000
# include <descrobject.h>
#endif

I don't see the purpose of this code.

[vstinner]

I wrote #126 to add these constants. Can you test my PR?

[rruuaanng]

I tested it and left a comment in your PR and the issue seems to be ok to be marked as resolved, but I need to wait for it to be merged into main.

[vstinner]

Fixed by 7eb512b.