bug#45934: native-comp - Dylib ID of ELN files not optimal

[Andrea Corallo]

"davide.restivo--- via \"Bug reports for GNU Emacs, the Swiss army knife
of text editors\"" <bug-gnu-emacs@gnu.org> writes:

[...]

> Since the tmp directory is stripped out and replaced with the
> destination directory, as you can see, all of the ELN files ends up with
> the same dylib ID, and this is not allowed on macOS. My suggestion here
> would be to add the 'install_name' [2] flag to gcc during the ELN files
> compilation replacing the 'fake.so' with the original .eln filename.
>
> Thanks and regards,
> Davide
>
>
> [1] https://github.com/daviderestivo/homebrew-emacs-head
> [2] gcc -o libdummy.dylib -install_name ${PREFIX}/lib/libdummy.dylib 

Hi Davide,

I'm really ignorant on MacOS so I'll comment for what I can.  I had a
look to the GCC doc [1] but I could not figure out if '-install_name' is
an option that goes to the compiler or the linker (nor I know what this
dylib ID exactly is).  If the flag is routed to the linker we should be
able to add it but only when libgccjit >= 9 is used.

Could you run a random compilation of something using '-install_name'
but adding also '-v' and report the console output so we can see where
the driver is routing the flag?

Thanks

  Andrea

[1] https://gcc.gnu.org/onlinedocs/gcc/Darwin-Options.html