Platform dependent code

[pedro-w]

Following on from #483,
As we know nearly all of Io is very portable C code, the main exception being the coroutine library.

I've come across a few problems with this not compiling on various platforms and also not working properly in certain circumstances. I am working on a patch to address all the things I have found but I think it is worth discussing a bit. I've been trying to get everything to work on Windows (x86, x64) , MacOS (ARM64) and Linux (ARM32, ARM64) but it's rather time consuming as these are different machines so I have to move between them.

In general the coroutine code is a bit of a tangle of #ifdefs which have accumulated and I was wondering if someone could take a longer view on tidying it up.

I will post my patch(es) as a draft PR soon, does that make sense?

[stevedekorte]

"coroutine code is a bit of a tangle" I agree. Do you think it would be better to split the code into many Coro.[hc] files like:

coroutine/{operating system}/{supported architecture}/Coro.[hc]

And have the build system choose the correct one to use? Many of these would be the same files (e.g. where ucontext or fibers can be used) but it still might be easier to understand and maintain.

[pedro-w]

Yes I think that would make sense ... as you say it's a matrix of OS vs CPU but not every combination needs its own file. I think Windows is its own thing (i.e. fibers) and 64-bit ARM seems to have a consistent ABI (at least between linux and macos). I don't know anything about Free/OpenBSD or PowerPC. Also, in the future, RISC-V might be added.

[stevedekorte]

Pedro, would you like to take a stab at getting Claude to do it?

[pedro-w]

I forgot to reply, sorry, but yes I am working on this.