Upstream patch `patch-apple-cross-3.13.patch`

[zanieb]

patch-apple-cross-3.13.patch

Python's configure doesn't support cross-compiling on Apple platforms.

This patch adds support for cross-compiling on Apple platforms (iOS, tvOS, watchOS).

Related:

• patch-apple-cross.patch (for Python ≤3.11)
• patch-apple-cross-3.12.patch (for Python 3.12)

[zanieb]

@freakboy3742 do these patches differ substantially from the BeeWare ones?

[freakboy3742]

@freakboy3742 do these patches differ substantially from the BeeWare ones?

@zanieb Yes :-)

3.13 doesn't require any patches for iOS. All the required patches have been merged into the 3.13 release. You can cross compile for iOS without any modifications to stock CPython sources. The buildbot has been verifying this for almost 2 years.

This is the current 3.13 patch we use (last updated for 3.13.8); the vast majority of it are patches for iOS that have been merged into 3.14+, but are useful for the 3.13 build (such as the reorganisation adding the Apple XCframework build script). However, there are some modifications to configure.ac, config.sub, platform.config.c, platform.py, and a handful of other files - and those modifications are all to support tvOS, watchOS and visionOS. Those changes are much more substantial than the content of the 3.13 file that you've shown.

The patch is much more substantial for 3.12; the state of that patch is a delta against 3.12.8, and contains everything that was merged into 3.13 to add iOS support, as well as the tvOS and watchOS patches. I've been focussing much more on 3.13+, so I haven't backported much of the work that has been done for iOS or other Apple platforms in the last year or so - most of that work has been test fixes or ergonomics related to the build process.

[zanieb]

Hm. Thanks for the details! Let me investigate what happens if I drop this patch then, I presume I added it for 3.13 for a reason?

[freakboy3742]

I can't comment on why it was added... but looking at the patch, L6-11 is redundant by inspection. I'd need to do a full audit to be certain, but I suspect a lot of the other changes would also be redundant or override default behavior as well.

[zanieb]

I had no clue what I was doing at the time :)

[zanieb]

3.13 fails with

cpython-3.13> configure: error: cross build not supported for x86_64-apple-darwin

It's not needed for 3.14+

[freakboy3742]

AFAIK, macOS builds have never been cross-builds - they're built native on x86 for x86, and on ARM for ARM, with universal2 builds being built on ARM (but those aren't cross builds - they're builds with multiple architectures produced on a single compilation pass)

[zanieb]

I'm not sure that's true for us, we're not using the universal builds here.