Swift Bindings for LLVM
Swift Bindings for LLVM is a part of the Swift project, and aims to make it easier and more convenient to use LLVM APIs from Swift code. It relies on the experimental Swift/C++ Interoperability, which allows calling C++ APIs directly from Swift, removing the need for a C bridging layer.
This is a work-in-progress. The design of the bindings will be changing as Swift/C++ Interoperability evolves.
Trying it out
Within the Swift compiler project
(This will be updated once the Swift compiler starts using Swift LLVM Bindings.)
As a standalone project
A Swift Development Snapshot toolchain is required to build the project. Using the latest available trunk snapshot is recommended.
Since the bindings rely on LLVM headers, you will need a fresh checkout of LLVM locally. Both upstream LLVM (llvm/llvm-project) and Apple’s LLVM fork (apple/llvm-project) are supported.
Similarly to LLVM, CMake is used to build the bindings. To configure the build process, run the following command:
cmake -G Ninja \
-D CMAKE_BUILD_TYPE=Debug \
-D CMAKE_Swift_COMPILER=/Library/Developer/Toolchains/swift-DEVELOPMENT-SNAPSHOT-{YYYY-MM-DD}.xctoolchain/usr/bin/swiftc \
-D LLVM_DIR={PATH_TO_LLVM_BUILD_ROOT}/lib/cmake/llvm \
-B {PATH_TO_BUILD_ROOT}
To build all of the bindings, run:
cmake --build {PATH_TO_BUILD_ROOT} --target all
To build the bindings for a specific LLVM module (e.g. LLVM_Utils), run:
cmake --build {PATH_TO_BUILD_ROOT} --target LLVM_Utils
Branching scheme
llvm.org/main branch tracks the main branch
of (llvm/llvm-project).
stable/YYYYMMDD branch tracks the corresponding stable/YYYYMMDD branch
of (apple/llvm-project).
Contributing
If you are working on a feature that you intend to use in SwiftCompilerSources,
you should create pull requests against two branches: llvm.org/main
and stable/YYYYMMDD. If you are merging the pull requests yourself, please
make sure you merge the pull request to llvm.org/main branch first.
Otherwise, you should create pull requests against llvm.org/main branch only.
