changeset 49879:dd804d83822c

setup: drop legacy osx compiler tuning to enable universal builds

This was triggering deprecation warnings about migrating to `packaging.version`
from `distutils` Version classes with `make local`.  But rather than migrate
that code, let's just get rid of some ~10-12 year old workarounds.  As a bonus,
the cext libraries that are built are now universal binaries containing x86_64
and arm64 images (at least when built on macOS 11.4 with Xcode 12.5 and the
universal version of Python 3.9.13).

Several things to note here:

   - Apple dropped support for 10.15 in Nov 2022, and OS X Lion that is
     referenced is 10.7 (unsupported since late 2014)
   - `xcode4` was basically always True because of the `>=` check (10.8 used
     Xcode 5, and I have Xcode 10.2 on 10.14)
   - `xcode51` was always False for modern-ish Xcode, because of the exact
     version string matching
   - Python 3.8 only supports OS X 10.9+; the Python 3.9.1+ universal installer
     is macOS 11+ only, and Python 3.10 drops the x86_64 installer to deliver
     only the universal installer.

All of this is to say, the only thing lost by dropping this code on modern Xcode
is that `os.environ['ARCHFLAGS'] = ''` is no longer set.  But we probably
shouldn't be setting that anymore, as shown by the universal libraries now being
generated.  I was able to `make local` and `python3 run-tests.py --local` with
python 3.9.9, Xcode 10.2, and macOS 10.14.6, and didn't incur any more than the
usual few test errors, so this should still work on some older versions of
macOS.

--- a/setup.py	Wed Jan 04 00:20:27 2023 -0500
+++ b/setup.py	Wed Jan 04 13:47:10 2023 -0500
@@ -126,11 +126,7 @@
     DistutilsError,
     DistutilsExecError,
 )
-from distutils.sysconfig import get_python_inc, get_config_var
-from distutils.version import StrictVersion
-
-# Explain to distutils.StrictVersion how our release candidates are versioned
-StrictVersion.version_re = re.compile(r'^(\d+)\.(\d+)(\.(\d+))?-?(rc(\d+))?$')
+from distutils.sysconfig import get_python_inc
 
 
 def write_if_changed(path, content):
@@ -1696,39 +1692,6 @@
     # form W.X.Y.Z, where W,X,Y,Z are numbers in the range 0..65535
     setupversion = setupversion.split(r'+', 1)[0]
 
-if sys.platform == 'darwin' and os.path.exists('/usr/bin/xcodebuild'):
-    version = runcmd(['/usr/bin/xcodebuild', '-version'], {})[1].splitlines()
-    if version:
-        version = version[0].decode('utf-8')
-        xcode4 = version.startswith('Xcode') and StrictVersion(
-            version.split()[1]
-        ) >= StrictVersion('4.0')
-        xcode51 = re.match(r'^Xcode\s+5\.1', version) is not None
-    else:
-        # xcodebuild returns empty on OS X Lion with XCode 4.3 not
-        # installed, but instead with only command-line tools. Assume
-        # that only happens on >= Lion, thus no PPC support.
-        xcode4 = True
-        xcode51 = False
-
-    # XCode 4.0 dropped support for ppc architecture, which is hardcoded in
-    # distutils.sysconfig
-    if xcode4:
-        os.environ['ARCHFLAGS'] = ''
-
-    # XCode 5.1 changes clang such that it now fails to compile if the
-    # -mno-fused-madd flag is passed, but the version of Python shipped with
-    # OS X 10.9 Mavericks includes this flag. This causes problems in all
-    # C extension modules, and a bug has been filed upstream at
-    # http://bugs.python.org/issue21244. We also need to patch this here
-    # so Mercurial can continue to compile in the meantime.
-    if xcode51:
-        cflags = get_config_var('CFLAGS')
-        if cflags and re.search(r'-mno-fused-madd\b', cflags) is not None:
-            os.environ['CFLAGS'] = (
-                os.environ.get('CFLAGS', '') + ' -Qunused-arguments'
-            )
-
 setup(
     name='mercurial',
     version=setupversion,