A mise backend plugin that builds LLVM tools (clang, lld, mlir, etc.) from source. Based on the vfox-style backend architecture.

This plugin manages LLVM toolchain installations by downloading the LLVM source and building requested tools from scratch. It handles version listing, source downloading with locking, core LLVM library builds, and tool-specific compilation.

• LLVM build system with cmake/ninja
• Version listing from GitHub releases
• Multiple tool support: clang, lld, mlir, bolt, polly, compiler-rt, libc, libcxx, libunwind, openmp
• build_cores option for setting symultaneous build threads
• clang_extras option to enable/disable clang-tools-extra
• build_sequentially option for serializing symultaneously requested builds
• Core build caching (built once, shared across tools)

• Windows compatibility testing
• Download prebuilt binaries option
• Improve PATH/LIB settings in exec_env
• Add remaining LLVM tools (lldb, flang, libclc, offload)
• Better detection/skipping of already-built tools
• Comprehensive testing

Add the plugin to your mise configuration:

[plugins]
llvm = "https://github.com/Quasiflo/llvm"

Then use tools:

mise use llvm:clang@latest

These tools need to be available on path for the LLVM build to succeed. You can generally use system inbuilt or global mise installed versions.

• cmake - Build system generator
• ninja - Fast parallel build tool
• python - Required for LLVM build system
• C++ compiler - g++, clang++, or MSVC

mise use -g cmake@latest ninja@latest python@latest

Configure tool builds in your mise.toml:

[tools]
"llvm:clang" = { 
version = "latest", 
build_cores = 8, # Number of parallel cores for building (Default: auto-detect)
clang_extras = false, # Enable/disable clang extra tools (clangd, clang-tidy, etc. Default: true)
build_sequentially = true # Force builds to run sequentially (useful when installing multiple tools at once)
}