libc++ support in GCC (was: gcc, AVX (and newer) intrinsics and binutils

[René J.V. Bertin]

Hello,

I have been working on a (rather simple) patch to get GCC's g++ compiler to generate executables that use libc++ instead of libstdc++ . That's a requirement to being able to use that compiler as a full and generally-usable alternative to clang++ .

Upstream seem receptive to the idea, evidently less to the current form of the patch. An acceptable form that can be presented for review upstream will still have the same effect though. 

I think thus that there's enough justification for adding a build variant for port:gcc6 and the upcoming release version of port:gcc7. Instead of waiting for upstream to implement the feature it would allow us (me) to contribute to and speed up its appearance in GCC.

Concretely: libc++ support g++ will be through a to-be-implemented -stdlib argument, just like it works in clang. Not particularly difficult to implement but probably an amount of work to get right that is not insignificant for something that in practice is icing on users like us who will almost exclusively use a single setting for that argument.

R.

-------------------------------
Forwarded message:
Date: Wednesday May 17 2017
From: redi at gcc dot gnu.org <gcc-bugzilla at gcc.gnu.org>
To: rjvbertin at gmail.com
Cc: 
Subject: [Bug target/80781] Feature request: build option to use libc++ instead of libstdc++ for increased usability on Mac


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80781


> Meaning "that G++ will one day have this kind of support for libc++"? Is
> there a timeline or something?

No. Somebody has to do the work. It will get into GCC if somebody does the
work, but not before then.