Linking OpenMP Statically on Mac

[Ángel González]

On 01/05/15 05:50, Rob McDonald wrote:
> When I specify -fopenmp, the program is dynamically linked to
> libgomp.1.dylib.  I read that -static is not supported on OSX, as the
> Apple system libraries are not provided with static variants.
>
> So, is there a way to statically link libgomp in this situation?
If you have/build libgomp as a static library, it should be possible to 
only link libcomp statically. If -fopenmp flag insists on linking 
dynamically, you may need to call the linker manually. But I think it 
could be done.

> Or, will I need to distribute libgomp.1.dylib with my program?  Does
> the license allow this?
IMHO it does. libgomp is GPL so you can always distribute it (following 
its license),
but given that libgomp is covered by the GCC Runtime Library Exception, 
I think
you may be able to redistribute just the binary file (I would still 
stick a note explaining
that it's an unchanged libgomp vX.Y by foo, though)
> https://www.gnu.org/licenses/gcc-exception-3.1-faq.en.html
> https://www.gnu.org/licenses/gcc-exception-3.1.en.html



> Being a good citizen, where should I put the
> file?  I would prefer my users not to have to use sudo to install if
> they don't absolutely have to.  My program is currently not a Package,
> it is just an executable and some data files distributed in a *.zip.
If you use a wrapper script using a LD_PRELOAD trick to load 
libgomp.1.dylib from the current folder, you can probably continue using 
a "plain-zip approach". Just note that the linker variables in Mac OS 
are named differently:
http://unix.stackexchange.com/questions/30444/libfaketime-and-mac-os-ld-preload#30449