[Bug bootstrap/107795] <limits.h> recursion through <syslimits.h> breaks non-GNU implementations of the C++ stdlib

["ldionne.2 at gmail dot com" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107795

--- Comment #4 from Louis Dionne <ldionne.2 at gmail dot com> ---
(In reply to Andrew Pinski from comment #2)
> You should not be building on top of GCC's limits.h header at all really.
> Rather implementations should have their own.

What do you mean by "implementations"? Do you mean implementations of the C
library or compiler implementations, or what?


(In reply to Jonathan Wakely from comment #3)
> (In reply to Andrew Pinski from comment #2)
> > Rather implementations should have their own.
> 
> Or just use GCC's one without change, which is what libstdc++ does. We don't
> provide any <limits.h> in libstdc++, only <climits>. When you #include
> <limits.h> with G++ you just get GCC's own <limits.h> as-is.

Yeah but we may need to add stuff to <limits.h> on some platforms, so we may
need to have such a header. Also, I assume you only do that for a subset of
headers, because you must have <foo.h> headers in libstdc++ for a few headers
that require adding const-correct overloads of e.g. `memchr`?