[cfe-dev] RFC: We should take a more conservative approach to libstdc++ compatibility...

[Marc Glisse]

On Thu, 10 Jan 2013, Chandler Carruth wrote:

> Greetings all! This is the result of a chat between Richard and myself just
> now.
>
> These days Clang does a great job of detecting GCC and libstdc++
> installations and using them... such a great job that Clang installed today
> will work with GCC 4.9 if such a thing existed and were installed.
>
> As we've noticed recently, this can cause problems, and now that we have
> clang releases and GCC releases with decent compatibility out in the wild
> (3.2 and 4.{6,7} resp.), I think we should take a different approach:
>
> 1) Set a max GCC version we use,

I would weaken it a bit by saying: only use a version higher than this 
hardcoded value if you couldn't find a safer one. Warn all you like (with 
-Wtoo-recent-libstdc++ on by default), but if there is only libstdc++-4.9 
on my machine and clang refuses to even try to use it, that's a pain.

-- 
Marc Glisse