clang-musl overlay

Overlay containing experimental clang-musl profile and related ebuilds.

Prequisite

• A working gentoo/musl system.
• Self-hosted clang compiler, with the default-libcxx USE flag enabled.
• Some knowledge of compilers, linkers and gentoo's package manager portage.

Installation

• Create a new file /etc/portage/repos.conf/clang-musl.conf with the following contents:

[clang-musl]
sync-uri = https://github.com/clang-musl-overlay/clang-musl-overlay.git
sync-type = git
location = /var/db/repos/clang-musl
sync-depth = 1

• Sync this new repo using emaint sync -r clang-musl or emerge --sync

Profiles

clang-musl overlay provides clang-musl and clang-musl/hardened profiles

Switching to clang-musl profile:

• Use eselect to list all the profiles. Note the new profile and select the profile

eselect profile set --force <profile>

Setting clang and llvm binutils as default

• Switch to clang-musl profile
• Unmerge gcc, binutils and their dependencies with a --depclean. emerge -c
• Merge sys-devel/llvm-conf. This should automatically set latest llvm/clang as your default toolchain.
  • Or you can run llvm-conf --enable-native-links --enable-clang-wrappers --enable-binutils-wrappers llvm-14
• Now you can run emerge -1euDN @world to rebuild everything with clang/llvm.

Issues

• Programs may fail to build when using clang. There are already patches for known issues at gentoo-patchset.
• LTO and other optimization may lead to build issues for some pkgs. Please report if you find any issue.