The cx Programming Language

cx (stylized as lowercase, not to be confused with languages called CX or Cx) is a C-family hybrid low-level/high-level programming language focused on runtime performance and developer productivity (in this order of priority). The language is simple and unopinionated, supporting imperative, generic, data-oriented, functional, and object-oriented programming. It compiles to efficient native code via LLVM or the C backend, with no garbage collection or hidden runtime.

To learn more about the language, visit the website:

cx-language.github.io/cx

For more code samples, see examples.

You can also read the language documentation in Markdown format under docs.

To ask a question or open a discussion, create an issue or join the cx Discord server.

Compiling cx requires a C++20 compiler, CMake 3.16 or newer, and LLVM/Clang 23.

On Ubuntu/Debian, install the prerequisites with:

wget https://apt.llvm.org/llvm.sh
chmod +x llvm.sh
sudo ./llvm.sh 23 all
sudo apt-get install -y cmake g++ python3-pip

On other distributions, install CMake and a C++ compiler with your package manager, then download and extract the pre-built LLVM/Clang 23 binaries (replace X64 with ARM64 on ARM):

curl -L -O https://github.com/llvm/llvm-project/releases/download/llvmorg-23.1.1/LLVM-23.1.1-Linux-X64.tar.xz
tar -xf LLVM-23.1.1-Linux-X64.tar.xz

Then run the following commands, with <llvm dir> set to /usr/lib/llvm-23 for apt installs or the extracted directory for tarball installs:

mkdir build && cd build
cmake .. -DCMAKE_PREFIX_PATH="<llvm dir>"
cmake --build .

brew install llvm@23 cmake

Then run the following commands:

mkdir build && cd build
cmake .. -DCMAKE_PREFIX_PATH="$(brew --prefix llvm@23)"
cmake --build .

Download and extract LLVM/Clang 23 pre-built binaries from https://github.com/llvm/llvm-project/releases. Then run the following commands:

mkdir build
cd build
cmake .. -DCMAKE_PREFIX_PATH="C:\path\to\llvm" -DCMAKE_GENERATOR_PLATFORM=x64 -Thost=x64
cmake --build .

The cx and cx-lsp binaries end up in the build directory.

For diagnostics, hover, go to definition, completions, find references, and semantic highlighting in any LSP-capable editor, see the language server setup guide. The cx-lsp binary is built alongside cx.

Contributions are welcome. See the GitHub issues and the Trello board for the project backlog.

Install lit and its optional dependencies via pip:

python3 -m pip install lit psutil

Some examples have extra prerequisites; see the README in each example directory for details.

Then invoke the following from the build directory:

cmake --build . --target check

This runs the full suite via CTest: the lit/compiler tests, the example programs (LLVM and C backends), the documentation snippets, and the language server end-to-end tests. Run a subset from the build directory with e.g. ctest -R 'docs-snippets'. To run a single compiler test file, invoke lit with the flags shown by ctest -N -V.

The C++ code style is enforced by ClangFormat:

• Run the format CMake target to format the code.
• Run the lint CMake target to check if the code is formatted.

To work on the browser playground or the website, see wasm/README.md (architecture, building, and testing of the WebAssembly frontend and the in-browser C toolchain). Run website/build-website.sh --serve to develop the website locally.

cx is licensed under the MIT license, a permissive free software license. See the file LICENSE.txt for the full license text.