swift-mirror/Runtimes/Supplemental

Swift Supplemental Libraries

The supplemental libraries are all libraries that are not one of the Core or overlay libraries. Each supplemental library builds as an independent project.

The supplemental libraries are:

• CxxInterop
• Differentiation
• Distributed
• Observation
• StringProcessing
• Runtime
• Synchronization

The top-level Supplemental CMakeLists supplies a super-build pattern for configuring and compiling each of the supplemental library projects through a single CMake invocation. The Swift_ENABLE_RUNTIMES CMake option enables the specified supplemental libraries. All libraries configured this way are built with the same compilers, against the same sysroot, with the same target triple and installed into the same location.

Super-Build

Configuring each project independently is tedious. The Supplemental directory contains a Super-Build CMakeLists that invokes the build of each of the supplemental libraries in the appropriate order, simplifying the process of building each library.

Important configuration variables:

• Swift_ENABLE_RUNTIMES: Used to configure which runtime libraries are built.

The super-build forwards the following variables to each sub-project unconditionally:

• BUILD_SHARED_LIBS
• CMAKE_BUILD_TYPE
• CMAKE_INSTALL_PREFIX
• CMAKE_COLOR_DIAGNOSTICS
• CMAKE_C_COMPILER
• CMAKE_C_COMPILER_TARGET
• CMAKE_CXX_COMPILER
• CMAKE_CXX_COMPILER_TARGET
• CMAKE_Swift_COMPILER
• CMAKE_Swift_COMPILER_TARGET

If set, the super-build forwards the following values to each sub-project:

• SwiftCore_DIR: Path to the SwiftCore build directory
• CMAKE_MAKE_PROGRAM: Path to ninja

The super-build is for convenience. If more fine-grained control is desired for configuring a specific runtime library, you may configure that library independently.