Installation

WeaveC currently ships source releases. Build it against an LLVM/Clang development installation, and keep that LLVM installation available at runtime. The CI-tested platforms are macOS and Linux.

1. Install the toolchain

You need CMake 3.25 or newer for the supplied presets, Ninja, a C++20 compiler, and the LLVM/Clang development libraries. LLVM 23.x is recommended; the project supports LLVM 20 and newer. Tests also require lit and LLVM’s FileCheck.

macOS

brew install cmake llvm ninja lit
export WEAVEC_LLVM_PREFIX="$(brew --prefix llvm)"

Apple’s system Clang can compile WeaveC, but the development libraries come from Homebrew’s LLVM package. Xcode does not include them.

Ubuntu / Debian

Install LLVM from the official LLVM packages for your distribution. Review the installer before running it with elevated privileges:

wget https://apt.llvm.org/llvm.sh
less llvm.sh
sudo bash llvm.sh 23 all
sudo apt-get install -y cmake ninja-build python3-venv
python3 -m venv .venv
. .venv/bin/activate
pip install lit==23.1.0
export WEAVEC_LLVM_PREFIX=/usr/lib/llvm-23
export CC=clang-23 CXX=clang++-23

Check cmake --version; older distributions may need a newer CMake installation to use the presets.

2. Get a release

Download the source archive and SHA256SUMS from GitHub Releases into the same directory. Verify the archive with one of:

shasum -a 256 -c SHA256SUMS  # macOS
sha256sum -c SHA256SUMS     # Linux

Extract weavec-X.Y.Z-source.tar.gz, replacing X.Y.Z with the downloaded version, and enter its weavec-X.Y.Z directory.

For development, you can instead clone the current source:

git clone https://github.com/weavefoundry/weavec.git
cd weavec

3. Build, test, and install

Run these commands from the source directory:

cmake --preset release -DWEAVEC_VERSION_SUFFIX=""
cmake --build --preset release
ctest --preset release
cmake --install build/release --prefix "$HOME/.local"
export PATH="$HOME/.local/bin:$PATH"

Add the PATH export to your shell configuration to retain it in new terminals. Use the developer guide for debug builds, alternative LLVM installations, and build options.

4. Verify the installation

weavec --version
weavec-cc --version

Both commands should print their version. If Clang resources or shared libraries cannot be found, check installation troubleshooting.

Next: Run your first check.