LLVM/Clang seems to be the future as far as open source compilers go. The FreeBSD developers switched to LLVM/Clang in FreeBSD 9 and the Debian project appears to be considering a switch as well. They did a survey that shows that only 8.8% of their packages fail to build with LLVM/Clang 3.0: http://clang.debian.net/ It is probably a good time to look into building Gentoo with LLVM/Clang. FreeBSD upstream has already switched, so this should work well for Gentoo/FreeBSD. With some work, this could be leveraged by Gentoo Linux and Gentoo Prefix as well. As per a chat I had with bonsaikitten (Patrick Lauer) in IRC, I am filing this bug to serve as a tracker for progress on this.
I found this project and then I think it's may be interesting: https://github.com/chneukirchen/obase They are porting the OpenBSD useland for Linux. In Arch Linux AUR are some PKGBUILDs about, but I don't know if already functional. https://aur.archlinux.org/packages.php?ID=56826
I'd love to start a project within the Gentoo community to start the transition from the inferior GCC to Clang. Would be a very interesting and rewarding project I think.
(In reply to comment #2) > I'd love to start a project within the Gentoo community to start the > transition from the inferior GCC to Clang. Would be a very interesting and > rewarding project I think. I am going to blame Hurricane Sandy for putting me behind on bug mail. Gentoo is quite large and I am one developer. It would be better to do this as a community effort and if people are interested in that, then it would be best to take this to the gentoo-dev mailing list. If you are strongly interested in doing this, I suggest that you subscribe to the gentoo-dev mailing list and send an email to the list about this. Instructions on how to subscribe are on the following webpage: http://www.gentoo.org/main/en/lists.xml
If we want have systemwide-clang first we need remove dependencies from gcc remove from all packages and first remove from llvm ebuild llvm don't need dependency on gcc we can check gcc version at pkg_pretend and throw error if have broken gcc version but this check need only if we use gcc as CC for build llvm. Determine which compiler we use we can in pkg_pretend, but we need remove gcc_version and Co from toolchain-funcs.eclass and split that in separate gcc-version.eclass or clang-vesion.eclass gcc-version use CPP for determine version of gcc, but for clang it's work too clang return 4.2 if CPP=clang and call gcc-version but... what does what mean? and determine compiler from tc-getCC it's not best way what if CC=cc and cc it's symlink to clang or script that call clang? maybe we have better solution? PS: dependencies to gcc don't need for all package systemwide compiler it's part of system and we have systemwide compiler in /usr/portage/profile/../packages systemwide compiler always have last supported version and if some package need specific version of system wide compiler we should determine this in pkg_pretend
There are a couple missing dependencies: bug 417795 (dev-libs/openssl) bug 458932 (media-libs/libaacplus) as well as a few I just filed: bug 502450 (app-crypt/seahorse) bug 502452 (dev-lang/tcc) bug 502454 (media-libs/gstreamer) bug 502458 (net-libs/glib-networking) bug 502460 (net-libs/libsoup) bug 502462 (sci-libs/fftw) bug 502464 (sys-apps/memtest86+) bug 502466 (sys-apps/ipmiutil) bug 502470 (sys-boot/efibootmgr) bug 502472 (sys-devel/autogen) bug 502474 (sys-fs/udisks) bug 502476 (sys-libs/glibc) bug 502478 (x11-libs/cairo) bug 502480 (x11-misc/lightdm) btw, bugzilla seems to have an off by one, it's skipping all odd numbers. See above numbers ;)
Redacting comment 6 per request: > I'm slowly (manually) moving lots of my packages over to LLVM/Clang (using > the environment portage feature). > Here's a gist of packages that work! (I'll update it periodically). > Once I'm finished with my porting, I'll also file a bug report for every > package that _doesn't_ work. > > [redacted dead URL]
app-text/tesseract-5.3.0 with USE="openmp" errors with "undefined symbol: __kmpc_global_thread_num"
Here's my current package.env for installed packages, that don't compile successfully with clang: =dev-lang/luajit-2.1.0_beta3_p20220127-r2 gcc =app-forensics/unhide-20210124 gcc =net-analyzer/bing-1.3.5 gcc =dev-lang/micropython-1.17 gcc dev-util/biew gcc sys-boot/syslinux gcc =app-office/dia-0.97.3-r1 gcc dev-java/icedtea gcc sys-devel/binutils gcc sys-libs/binutils-libs gcc cross-arm-none-linux-gnueabi/binutils gcc cross-arm-none-linux-gnueabi/gcc gcc cross-arm-none-linux-gnueabi/glibc gcc dev-libs/libpwquality gcc sci-physics/xfoil gcc x11-misc/redshift gcc =dev-util/geany-plugins-1.38-r5 gcc =dev-util/bazel-5.0.0 gcc =dev-util/memprof-0.6.2-r1 gcc =app-crypt/seahorse-43.0-r2 gcc =dev-lang/python-3.11.2_p2 gcc =dev-lang/python-3.11.3 gcc dev-qt/qtcore gcc dev-qt/qtwebengine gcc =dev-vcs/cvs-1.12.12-r14 gcc =media-libs/zvbi-0.2.35-r2 gcc =sys-apps/sandbox-2.29 gcc =app-text/enchant-1.6.1-r2 gcc =dev-util/colm-0.14.7 gcc =media-libs/t1lib-5.1.2-r3 gcc =media-libs/portaudio-19.07.00-r2 gcc =sci-libs/hdf5-1.12.2-r6 gcc =app-cdr/cdrtools-3.02_alpha09-r3 gcc =net-dns/bind-tools-9.16.37-r1 gcc =media-libs/libggi-2.2.2-r1 gcc =media-libs/libggiwmh-0.3.2-r1 gcc =dev-lang/mono-6.12.0.122 gcc =sci-libs/lapack-3.11 gcc =dev-python/numpy-1.24.2 gcc =sys-libs/libomp-15.0.7-r2 gcc =app-text/gtkspell-2.0.16-r2 gcc =xfce-extra/xfce4-sensors-plugin-1.4.4 gcc dev-lang/php gcc dev-lang/php gcc media-video/ffmpeg gcc =media-libs/sdl2-image-2.0.5_p20210328-r1 gcc =media-libs/sdl2-mixer-2.6.2-r1 gcc =media-libs/sdl2-net-2.0.1 gcc =media-libs/sdl-net-1.2.8_p20221010 gcc =media-libs/libquicktime-1.2.4-r4 gcc =app-emulation/fs-uae-3.1.66 gcc =games-fps/quake2-icculus-0.16.1-r2 gcc =media-video/makemkv-1.17.3 gcc media-video/mplayer gcc =media-gfx/exact-image-1.0.2-r8 gcc =media-video/transcode-1.1.7-r6 gcc =sys-libs/ncurses-6.4_p20230401 gcc =dev-python/cryptography-40.0.2 gcc app-office/libreoffice gcc app-crypt/seahorse gcc media-sound/audacity gcc
Here is mine for things that currently don't build with clang-15 and clang-16. The last @world rebuild wasn't long ago so this should still be accurate. Packages like gcc,glibc,... that are known to not support clang are not in the list. app-cdr/cdrtools compiler-gcc # configure error app-emulation/virtualbox compiler-gcc # ld.lld error app-emulation/qemu compiler-gcc # ERROR: sizeof(size_t) doesn't match dev-lang/mono compiler-gcc # ld.lld error dev-libs/libsecp256k1 compiler-gcc # unrecognized command-line option dev-util/ostree compiler-gcc # ld.lld error dev-python/ruamel-yaml-clib compiler-gcc # incompatible function pointer types dev-qt/qtwebengine compiler-gcc # build fails media-libs/libpano13 compiler-gcc # build fails media-libs/tg_owt compiler-gcc # build fails media-libs/phonon compiler-gcc # build fails media-libs/vigra compiler-gcc # build fails net-print/hplip compiler-gcc # error: ISO C++17 sys-apps/pciutils compiler-gcc # ld.lld sys-boot/syslinux compiler-gcc # 'stdarg.h' file not found sys-devel/bin86 compiler-gcc # error: ISO C99 sys-devel/binutils compiler-gcc # configure: error: AR sys-libs/db compiler-gcc # build fails sys-process/tini compiler-gcc # ld.lld error
Here's my current list: sys-apps/systemd compiler-gcc net-dialup/ppp compiler-gcc media-libs/audiofile compiler-gcc app-cdr/cdrtools compiler-gcc app-crypt/chntpw compiler-gcc I use KDE Plasma, but I have -webengine set. systemd will compile with clang if boot/gnuefi flags are unset, but I enabled those for systemd-boot.
My lists: Requires gcc: - sys-apps/memtest86+ - sys-libs/glibc - dev-java/openjdk - sys-devel/gcc - sys-apps/flashrom - sys-devel/binutils - app-cdr/cdrtools - media-video/makemkv (doesn't compile with llvm's libcxx even with gcc using CXXFLAGS="-nostdinc++ -I/usr/include/c++/v1 ${COMMON_FLAGS} -nodefaultlibs -lc++ -lc++abi -lm -lc -lgcc_s -lgcc") Requires LDFLAGS="-Wl,--undefined-version": - sys-apps/keyutils - sys-libs/tdb - sys-libs/talloc - sys-libs/tevent - sys-libs/ldb - games-util/mangohud - net-libs/gtk-vnc - net-fs/samba Requires compilation without lto: - app-benchmarks/stress-ng - dev-python/pypy3_10
