Re: [PATCH] libgccjit: Make new_array_type take unsigned long

[David Malcolm <dmalcolm@redhat.com>]

On Thu, 2023-12-07 at 17:29 -0500, Antoni Boucher wrote:
> Hi.
> This patches update gcc_jit_context_new_array_type to take the size
> as
> an unsigned long instead of a int, to allow creating bigger array
> types.
> 
> I haven't written the ChangeLog yet because I wasn't sure it's
> allowed
> to change the type of a function like that.
> If it isn't, what would you suggest?

We've kept ABI compatibility all the way back to the version in GCC 5,
so it seems a shame to break ABI.

How about a new API entrypoint:
  gcc_jit_context_new_array_type_unsigned_long
whilst keeping the old one.

Then everything internally can use "unsigned long"; we just keep the
old entrypoint accepting int (which internally promotes the arg to
unsigned long, if positive, sharing all the implementation).

Alternatively, I think there may be a way to do this with symbol
versioning:
  https://gcc.gnu.org/wiki/SymbolVersioning
see e.g. Section 3.7 of Ulrich Drepper's "How To Write Shared
Libraries", but I'm a bit wary of cross-platform compatibility with
that.

Dave