the patch has been backported for RC1 Thanks for reporting it Best regards Alin
On Thu, Oct 12, 2023 at 4:07 AM Xiang Xiao <xiaoxiang781...@gmail.com> wrote: > A recent change limits c++20 requirement to libcxx: > https://github.com/apache/nuttx/pull/10860 > The owner of libcxx decided not to support the build of libcxx by > an old compiler, It's very hard to sync with the last libcxx version, and > keep the support of the old compiler at the same time in the long term. > > > On Thu, Oct 12, 2023 at 7:31 AM Tomek CEDRO <to...@cedro.info> wrote: > > > On Thu, Oct 12, 2023 at 12:19 AM Nathan Hartman wrote: > > > On Wed, Oct 11, 2023 at 3:21 PM Tomek CEDRO wrote: > > > > Hello world, > > > > I have encountered a basic esp32:nsh build error in nuttx-12.3.0-RC0 > > > > related to xtensa g++ 8.4.0 compiler: > > > > xtensa-esp32-elf-g++: error: unrecognized command line option > > > > '-std=gnu++20'; did you mean '-std=gnu++2a'? > > > > > > This was changed in d6453cfc3cd4771a5221528cab3056660be4b1e3 (PR # > 8244). > > > > > > See mail thread: > > > https://lists.apache.org/thread/rkq99os8ql28bv1w8fy5mdqwl3h2vp6m > > > > > > The workaround is to set Kconfig CXX_STANDARD to gnu++2a instead of > > gnu++20. > > > > Thank you Nathan :-) > > > > I am following the mailing list and github PRs so I know this was > > recent change to make better compatibility with C++ and this is fine > > to have this support. But this should not happen at the cost of > > standard build setup and/or enforcing specific compilers / versions to > > everyone by default (see inviolables). This probably also impacts > > other platforms/architectures, especially the older ones. I am sure > > this can be fixed easily. > > > > I am sorry for giving my first -1 as I know there are many new > > features and improvements in the RC, but I am afraid if we don't fix > > that compiler problem now then there will be no incentive to do this > > in future. > > > > > > > It would be nice if the build system could automatically detect the > > > compiler version and set this value accordingly and automatically, > > > without a Kconfig. IIRC there are programs in tools that determine > > > compiler options based on the compiler and version. (Can't remember > > > details off the top of my head at the moment.) > > > > Yes that would be perfect! > > > > Quick search shows that people do this in many ways by calling > > compiler with a list of flags and checking return status for each flag > > to see if it is supported. > > > > Current C++ standards supported by GCC and CLANG are listed here: > > https://gcc.gnu.org/projects/cxx-status.html > > https://clang.llvm.org/cxx_status.html > > > > Quote from GCC: > > C++20 Support in GCC > > GCC has experimental support for the latest revision of the C++ > > standard, which was published in 2020. The status of C++20 library > > features is described in the library documentation. > > C++20 features are available since GCC 8. To enable C++20 support, add > > the command-line parameter -std=c++20 (use -std=c++2a in GCC 9 and > > earlier) to your g++ command line. Or, to enable GNU extensions in > > addition to C++20 features, add -std=gnu++20. > > > > Maybe a simple check can be added to a Makefile? > > > > Maybe a C++ support could be added as option that is disabled by > > default (+compiler check)? > > > > > > > > REMARKS: > > > > 1. flock is a new system build dependency. > > > > > > I think documentation needs to be updated? I think not all systems > > > have flock. Is it a Linux-only thing? (Non-BSD?) > > > > Not a big deal I guess :-) As compared to 12.2.1 in order to build > > 12.3.0-RC0 I had to install additional "flock" application. It comes > > from Linux and it is available on FreeBSD. On macOS (BSD) it is not > > part of the base system too and it can be installed with brew. It > > seems to be fairly old commit that fixes parallel build (which I also > > use). Just a notice :-) > > > > > > > https://github.com/apache/nuttx-apps/blob/91a682f11bba1a537bd095cef45f17db57c9e7b9/Make.defs#L157 > > > > > https://github.com/apache/nuttx-apps/commit/f774e8ee7202a61bcf64a93b2f3ddfd240288cf1 > > > > Thank you :-) > > Tomek > > > > -- > > CeDeROM, SQ7MHZ, http://www.tomek.cedro.info > > >
