https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118831
Jerry DeLisle <jvdelisle at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jvdelisle at gcc dot gnu.org
--- Comment #15 from Jerry DeLisle <jvdelisle at gcc dot gnu.org> ---
(In reply to jcldc13 from comment #13)
> (In reply to Thomas Koenig from comment #12)
> > (In reply to jcldc13 from comment #10)
> > > (In reply to Jakub Jelinek from comment #6)
>
> > > You can run by yourself my test case on x86 computer, and you'll always
> > > get,
> > > pretty sure, "hello world" stored in "myval" variable. No random value,
> > > except from aarch64 computer (at least from a Mac ARM)
> >
> > Jakub already explained this. This happens to work on x86_64 because of
> > its application binary interface (aka the argument passing conventions).
> > aarch64 has a different convention, and there it does not work.
>
> You say aarch64 has a different convention/behavior, it was not clear for
> me in the previous posts. But ok then.
>
> >
> > > Well, you are all gcc experts, and I am just a programmer. But how to
> > > explain I have never got an issue on x86 if you say that I should get
> > > random
> > > values ... ?
> >
> > See above, this "works" on x86, but not on aarch64. If you want
> > your code to work on other architectures, you will have to rewrite
> > the C functions as non-variadic (without the ...) and then
> > call the right one, preferably using C interoperability.
>
> The idea of my library, was to use variadic C language function because it
> was very useful. Tons of fortran programs have been developed using this
> library. I can't change them, plus modify the library. I am gonna stop
> developing on Mac arm then.
>
I am wondering if you could use Fortran optional arguments to accomplish the
equivalent of what you need. How many variations of arguments do you have?
Email me off of bugzilla if you want to explore this a little.
