CppBundler

A tool to bundle custom headers into one single .cpp file.

Dependencies

This tool is based on LLVM/Clang. You can either use system libraries or build strictly against a custom LLVM version.

Option 1: System Dependencies (Dynamic Build)

On Ubuntu/Debian:

$ sudo apt install llvm-dev libclang-dev build-essential cmake ninja-build

Option 2: Custom LLVM (Dynamic & Static Build)

For a fully static binary, you need to build LLVM from source or use a static distribution.

# Example: Build LLVM 21.1.0 from source
git clone https://github.com/llvm/llvm-project.git
cd llvm-project
git checkout llvmorg-21.1.0 
cmake -S llvm -B build -G Ninja \
    -DCMAKE_INSTALL_PREFIX=$HOME/llvm-install \
    -DCMAKE_BUILD_TYPE=Release \
    -DLLVM_ENABLE_PROJECTS="clang" \
    -DLLVM_ENABLE_ZSTD=OFF \
    -DBUILD_SHARED_LIBS=OFF
cmake --build build --target install

Build

Dynamic Build

System Dependencies:

cmake -S . -B build -G Ninja
cmake --build build

Custom LLVM: If you have a custom LLVM installed (e.g. in ~/llvm-install) but want to link dynamically:

cmake -S . -B build -G Ninja \
    -DLLVM_DIR=$HOME/llvm-install/lib/cmake/llvm \
    -DClang_DIR=$HOME/llvm-install/lib/cmake/clang

cmake --build build

Static Build

If you built LLVM manually as above:

cmake -S . -B build -G Ninja \
    -DBUILD_STATIC=ON \
    -DUSE_STATIC_CRT=ON \
    -DLLVM_DIR=$HOME/llvm-install/lib/cmake/llvm \
    -DClang_DIR=$HOME/llvm-install/lib/cmake/clang

cmake --build build

Usage

$ ./build/cpp-bundle FILE [OPTIONS]...

Options

Since this tool is based on LLVM/Clang preprocessor, you could use the same options to bundle your code.

Example Use Case

It is common to use a library in online competitive programming contests like Codeforces, AtCoder, etc. However, this kind of contest only allows you to submit a single C++ code. Therefore, if we modularize our library, we need to bundle them.