Re: [PATCH v3 2/7] gdb: fail configure if Python version is too old for limited API

[Tom Tromey <tom@tromey.com>]

>>>>> Matthieu Longo <matthieu.longo@arm.com> writes:

> GDB can be built against the Python limited API using the configure
> flag '--enable-py-limited-api=yes'. This flag is currently experimental,
> and the build is not yet fully successful. Today, the minimum required
> Python version for this option is 3.11. This requirement is not final
> and will be raised to a later version as the migration progresses.

> However, the configure script does not currently report an error if an
> older version of Python is used. Instead, the build fails later with
> numerous errors that are difficult to relate to Python limited API
> compatiblity.

> This patch adds a version check when '--enable-py-limited-api=yes' is
> specified, ensuring that the provided Python version meets the minimum
> requirements for the limited API support. If it does not, configure will
> now fail with a clear error message.

Sorry about the delay on this.

I'm a bit worried about adding a bunch of new python-related configury.
Like are we sure it will agree with what's already in there?  As in,
picking up the same version from the same place, etc?  For instance does
this new code respect --with-python-libdir?

I wonder if instead there could just be a new compile test that is run
when --enable-py-limited-api is used.  This test could just check
PY_VERSION_HEX and #error on failure.

Wouldn't that have the same effect but without adding a ton of new code?

TBH I'd even be happy with not doing this check in configure at all and
saying that if you specify --enable-py-limited-api then you should know
what you're doing and if you mess up you'll just get compile-time
errors.  That is, stick the check in python-internal.h.

Tom