llvmenv

Manage multiple LLVM/Clang builds. A fork of the original llvmenv project specifically made for Metal.

Install

0. Install cmake, builder (make/ninja), and C++ compiler (g++/clang++)
1. Install Rust using rustup or any other method. The minimum supported Rust version is currently 1.48.0.
2. cargo install llvmenv

Basic Usage

To install a specific version of LLVM after following the installation steps above, run these shell commands ("10.0.0" can be replaced with any other version found with llvmenv entries):

llvmenv init
llvmenv entries
llvmenv build-entry 10.0.0

zsh integration

You can swtich LLVM/Clang builds automatically using zsh precmd-hook. Please add a line into your .zshrc:

source <(llvmenv zsh)

If $LLVMENV_RUST_BINDING environmental value is non-zero, llvmenv exports LLVM_SYS_60_PREFIX=$(llvmenv prefix) in addition to $PATH.

export LLVMENV_RUST_BINDING=1
source <(llvmenv zsh)

This is useful for llvm-sys.rs users. Be sure that this env value will not be unset by llvmenv, only overwrite.

Concepts

entry

• entry describes how to compile LLVM/Clang
• Two types of entries
  • Remote: Download LLVM from Git/SVN repository or Tar archive, and then build
  • Local: Build locally cloned LLVM source
• See the module document for detail

build

• build is a directory where compiled executables (e.g. clang) and libraries are installed.
• They are compiled by llvmenv build-entry, and placed at $XDG_DATA_HOME/llvmenv (usually $HOME/.local/share/llvmenv).
• There is a special build, "system", which uses system's executables.

global/local prefix

• llvmenv prefix returns the path of the current build (e.g. $XDG_DATA_HOME/llvmenv/llvm-dev, or /usr for system build).
• llvmenv global [name] sets default build, and llvmenv local [name] sets directory-local build by creating .llvmenv text file.
• You can confirm which .llvmenv sets the current prefix by llvmenv prefix -v.