is overriden with the CC environment variable, use the new compiler as
the default for linking if LDSHARED is not also overriden. This restores
Distutils behavior introduced in 3.2.3 and inadvertently dropped in 3.3.0.
tailoring for universal builds by factoring out common OS X-specific
customizations from sysconfig, distutils.sysconfig, distutils.util,
and distutils.unixccompiler into a new module _osx_support that can
eventually also be used by packaging.
In particular, fix extension module build failures when trying to use
32-bit-only installer Pythons on systems with Xcode 4 (currently
OS X 10.8, 10.7, and optionally 10.6).
* Backport 3.3.0 fixes to 3.2 branch (for release in 3.2.4)
* Since Xcode 4 removes ppc support, extension module builds now
check for ppc compiler support and by default remove ppc and
ppc64 archs when they are not available.
* Extension module builds now revert to using system installed
headers and libs (/usr and /System/Library) if the SDK used
to build the interpreter is not installed or has moved.
* Try to avoid building extension modules with deprecated
and problematic Apple llvm-gcc compiler. If original compiler
is not available, use clang instead by default.
- Try to avoid building Python or extension modules with problematic
llvm-gcc compiler.
- Since Xcode 4 removes ppc support, extension module builds now
check for ppc compiler support and automatically remove ppc and
ppc64 archs when not available.
- Since Xcode 4 no longer install SDKs in default locations,
extension module builds now revert to using installed headers
and libs if the SDK used to build the interpreter is not
available.
- Update ./configure to use better defaults for universal builds;
in particular, --enable-universalsdk=yes uses the Xcode default
SDK and --with-universal-archs now defaults to "intel" if ppc
not available.
Distutils-based packages with C extension modules may fail because
Apple has removed gcc-4.2, the version used to build python.org
64-bit/32-bit Pythons. If the user does not explicitly override
the default C compiler by setting the CC environment variable,
Distutils will now attempt to compile extension modules with clang
if gcc-4.2 is required but not found. Also as a convenience, if
the user does explicitly set CC, substitute its value as the default
compiler in the Distutils LDSHARED configuration variable for OS X.
(Note, the python.org 32-bit-only Pythons use gcc-4.0 and the 10.4u
SDK, neither of which are available in Xcode 4. This change does not
attempt to override settings to support their use with Xcode 4.)
set the MACOSX_DEPLOYMENT_TARGET env variable for the interpreter process
on OS X. This could cause failures in non-distutils subprocesses and was
unreliable since tests or user programs could modify the interpreter
environment after distutils set it. Instead, have distutils set the
the deployment target only in the environment of each build subprocess.
Continue to use the previous algorithm for deriving the deployment target
value:
if MACOSX_DEPLOYMENT_TARGET is not set in the interpreter's env:
use the interpreter build configure MACOSX_DEPLOYMENT_TARGET
elif the MACOSX_DEPLOYMENT_TARGET env value >= configure value:
use the env MACOSX_DEPLOYMENT_TARGET
else: # env value less than interpreter build configure value
raise exception
This allows building extensions that can only run on newer versions of
the OS than the version python was built for, for example with a python
built for 10.3 or later and an extension that needs to be built for 10.5.
Without this patch python will fail to start properly when the environment
variable MACOSX_DEPLOYMENT_TARGET is set on MacOSX and has a value that is
not compatible with the value during Python's build. This is caused by code
in sysconfig that was only meant to be used in disutils.
This was done in r80805 (#7908) and erroneously brought back by the
distutils revert. This commit removes more code than the original,
which was uncomplete. There is no NEWS entry, like in r80805.
