Re: infer GCC_REQD from USE_LANGUAGES

[Greg Troxel <gdt%lexort.com@localhost>]

maya%netbsd.org@localhost writes:

> I think the way to go forward is,
>
> - Add a test to see if the previous libstdc++ is built with ABI compat
> (NetBSD as of 8.0 and most linux distros effectively had a major bump)
>
> - Do a better job of mirroring the major number of libstdc++
> I have sed thing to change it to 7.x, but NetBSD has since bumped it
> again.

the above two sound good to me, including explaining more.  I find this confusing.

> - Declare one GCC to be the one override GCC, if the existing one is
>   insufficient.
> I've been reluctant to do this, because I know it's good for me in
> NetBSD, but I don't know what it means for people who use just pkgsrc
> GCC.
>
> GCC 7 or 8 will be good.

That is more or less what the wiki proposal says.

>
> that is, try to create libstdc++ from pkgsrc to be as compatible as
> possible. At least compare the output of `nm --defined-only` between
> them to see if it is the same and try to reach it.

I think we need to say that libstdc++ built from pkgsrc should be set up
the same way as base, relative to ABI compat decision and shlib major.
Is that what you mean?