[MacPorts] #37732: cmake portgroup needs an option to disable use of CMAKE_OSX_ARCHITECTURES

[MacPorts]

#37732: cmake portgroup needs an option to disable use of  CMAKE_OSX_ARCHITECTURES
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  Reporter:  mojca@…  |      Owner:  macports-tickets@…
      Type:  defect   |     Status:  reopened
  Priority:  High     |  Milestone:
 Component:  ports    |    Version:
Resolution:           |   Keywords:
      Port:           |
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Comment (by mojca@…):

 Replying to [comment:23 rjvbertin@…]:
 > Replying to [comment:14 mojca@…]:
 > > The CMake developers have confirmed the bug but aren't likely to act
 on it any time soon. CMake simply applies the flag to any given compiler
 on Mac OS X when CMAKE_OSX_ARCHITECTURES is present:
 http://thread.gmane.org/gmane.comp.programming.tools.cmake.devel/5876.
 >
 > Is the location in the CMake source code (or the core .cmake files)
 where this happens identified?

 Yes. See the bug report:
   * http://www.cmake.org/Bug/view.php?id=14252

 > IIUC correcting the issue would require adding a list of compilers that
 don't understand the -arch flag, and take appropriate action for those?

 Adding `-arch` flags to `FFLAGS` is problematic in 99% cases anyway. If
 they could be removed, that would solve almost all the problems out there.

 > Alternatively, how about replacing `-arch i386` with `-m32` and `-arch
 x86_64` with `-m64` for GCC compilers, on OS X versions where clang is the
 default (10.7 and higher)?

 And breaking most of universal builds?

 We just need to solve a problem for a very small number of ports that use
 a fortran compiler and cannot use the `-arch` flag. On the other hand it
 might be that this is no longer an issue with fortran compilers from the
 latest gcc versions. Maybe we should just test that and conclude that a
 fix is no longer needed.

 > The original comment states
 > > It seems that one can use -m32 with both to get 32-bit i386 binaries,
 but I cannot try it out without recompiling gcc with +universal
 > is that because of (runtime) libraries that must be present in 32bit
 version?

 I'm not sure if I understand the question, but it's also possible that I
 don't know the answer.

 >> and I don't know yet how to make universal binaries with that approach.

 Read as: one can get universal binaries with `xFLAGS="-arch i386 -arch
 x86_64"`. Setting `xFLAGS="-m32 -m64"` probably doesn't give you universal
 binaries?

-- 
Ticket URL: <https://trac.macports.org/ticket/37732#comment:24>
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