Re: [musl] __MUSL__ macro

[Alastair Houghton <ahoughton@apple.com>]

On 7 Jul 2023, at 16:45, Rich Felker <dalias@libc.org> wrote:
> 
> If we make a macro that says "you can now rely on implementation
> details of musl version x.y.z" and people do that, then it ceases to
> work in a future version, it's our fault, and people rightly blame us.

I don’t think that’s true at all - people tend to blame whoever is in front of them, which is probably not going to be musl but something higher up the stack.  In many cases projects can detect the musl version already, either at configuration time by examining the version string, or by specifying it as part of their build.  Both of those things would have *exactly* that same downside, and the only way to remove that would be to do away with a version number altogether... which nobody is seriously proposing, right?

The *only* thing you’re actually preventing here is detecting the musl version *in the preprocessor*.  And only in situations where the project itself can’t somehow supply a relevant macro definition.

Kind regards,

Alastair.