Hi Iain, May I ask why we need to specify --with-gxx-libcxx-include-dir= at compile/configure time of GCC? While in clang equivalent, -stdlib= doesn't require so.
thanks, Shivam On Sat, Apr 2, 2022 at 7:32 PM Shivam Gupta <shivam98....@gmail.com> wrote: > Hi Iain, > > Thank you for the quick response and the effort to make that feature > available. > > When I reconfigured/build GCC > with --with-gxx-libcxx-include-dir=/usr/include/c++/v1/ , -stdlib= option > is now available to take libc++. > > thanks, > Shivam. > > On Sat, Apr 2, 2022 at 3:21 PM Iain Sandoe <i...@sandoe.co.uk> wrote: > >> Hi Shivam, >> >> > On 2 Apr 2022, at 06:57, Shivam Gupta <shivam98....@gmail.com> wrote: >> > >> > I saw your last year's mail for the same topic on the GCC mailing list - >> https://gcc.gnu.org/pipermail/gcc/2020-March/000230.html. >> >> The patch was applied to GCC-11 (so is available one GCC-11 branch and >> will be on GCC-12 when that is released). >> > >> > I tried today but this option is still not available. >> >> The option has to be configured when the compiler is built, that also >> means that you have to install (and point the configure to) a suitable set >> of libc++ headers from the LLVM project (e.g. there is a set here: >> https://github.com/iains/llvm-project/tree/9.0.1-gcc-stdlib). >> >> Generally, GCC is very compatible with the libc++ headers (the changes I >> made on that branch were mostly to deal with <coroutine> being in std:: for >> GCC and std::experimental:: for LLVM-9). For LLVM libc++ earlier than 9 >> there is a missing symbol that GCC uses - but that can be worked around too. >> >> There have been some changes in more recent (in particular, LLVM-14/main) >> libc++ that should make it more compatible. >> >> Of course, you should pick a version of the libc++ headers than matches >> the version used on your system (9 was used for quite a long time, but >> recent xcode headers are newer). >> >> Given that this involves cross-project sources and choosing a suitable >> set, probably it is a job for the distributions (e.g. homebrew, macports >> etc) to arrange or, for self-built compilers, following in the general >> comments above. >> >> FWIW, I have used this to build quite a few OSS projects on a number of >> Darwin versions (hence the comment about GCC being very compatible with >> libc++). >> >> thanks, >> Iain. >> >>
