bpo-41100: add runtime checks for MACOSX_DEPLOYMENT_TARGET=10.10 #21577
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In order to support a universal2 build, supporitng Mac OS 11 on arm64 and Mac OS on x86_64 going back to 10.10, we need to add in runtime checks for functions that will be detected as present by autoconf, because they are in the SDK, but which did not exist in Mac OS 10.10. This fixes all the instances of -WWunguarded-availability-new when building with MACOSX_DEPLOYMENT_TARGET=10.10
lawrence-danna-apple
requested review from
abalkin,
pganssle and
tiran
as code owners
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Thanks for the PR. @ronaldoussoren is working on a similar one at the moment. He can review and resolve differences. |
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I have a similar patch in #21583, but that one is targeting macOS 10.9 instead of 10.10 and is incomplete and as of yet untested ("it compiles therefore it is correct"). I like your approach with HAVE_..._RUNTIME macro's, that reduces the amount of cruft compared with my approach. |
configure.ac
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| @@ -3825,6 +3825,19 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ | |||
| AC_MSG_RESULT(yes) | |||
| ]) | |||
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| AC_MSG_CHECKING([to see if the compiler supports __builtin_available]) | |||
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It is not necessary to test for this in a configure script, the following should work in a header file:
#ifdef __has_builtin
#if __has_builtin(__builtin_available)
#define HAVE_BUILTIN_AVAILABLE 1
#endif
#endif
Modules/posixmodule.c
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| int async_err = 0; | ||
| struct iovec *iov; | ||
| Py_buffer *buf; | ||
| if (HAVE_PWRITEV_RUNTIME) { |
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same as in os_preadv.
Modules/posixmodule.c
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| int async_err = 0; | ||
| struct iovec *iov; | ||
| Py_buffer *buf; | ||
| if (HAVE_PREADV_RUNTIME) { |
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I'd just ignore the compiler warning here, as this function will be removed from the module when HAVE_PREADV_RUNTIME is false.
Modules/posixmodule.c
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| #define HAVE_FUTIMENS_RUNTIME __builtin_available(macos 10.13, ios 11, tvos 11, watchos 4, *) | ||
| #define HAVE_PREADV_RUNTIME __builtin_available(macos 10.16, ios 14, tvos 14, watchos 7, *) | ||
| #define HAVE_PWRITEV_RUNTIME __builtin_available(macos 10.16, ios 14, tvos 14, watchos 7, *) | ||
| #define HAVE_POSIX_SPAWN_SETSID_RUNTIME __builtin_available(macos 10.15, ios 13, tvos 13, watchos 6, *) |
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Is this (the introduction of POSIX_SPAWN_SETSID) documented somewhere?
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I couldn't find any proper documentation, I got 10.15 by looking up which version of xnu introduced it.
https://opensource.apple.com/source/xnu/xnu-4903.270.47/bsd/sys/spawn.h.auto.html
https://opensource.apple.com/source/xnu/xnu-6153.11.26/bsd/sys/spawn.h.auto.html
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It is 10.15. I know because I asked for it (cf. FB5361314 aka rdar://43247036).
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Thanks for the PR. The changes in the PR have been used as the basis for changes in GH-22855. |
In order to support a universal2 build, supporitng Mac OS 11 on arm64 and Mac OS on
x86_64 going back to 10.10, we need to add in runtime checks for functions that will
be detected as present by autoconf, because they are in the SDK, but which did not
exist in Mac OS 10.10. This fixes all the instances of -WWunguarded-availability-new
when building with MACOSX_DEPLOYMENT_TARGET=10.10
https://bugs.python.org/issue41100