| .. _cmake_build_rules: |
| |
| =========================== |
| The libc CMake build system |
| =========================== |
| |
| At the cost of verbosity, we want to keep the build system of LLVM libc |
| as simple as possible. We also want to be highly modular with our build |
| targets. This makes picking and choosing desired pieces a straightforward |
| task. |
| |
| Targets for entrypoints |
| ----------------------- |
| |
| Every entrypoint in LLVM-libc has its own build target. This target is listed |
| using the ``add_entrypoint_object`` rule. This rule generates a single object |
| file containing the implementation of the entrypoint. |
| |
| Targets for redirecting entrypoints are also listed using the |
| ``add_entrypoint_object`` rule. However, one will have to additionally specify |
| the ``REDIRECTED`` option with the rule. |
| |
| Targets for entrypoint libraries |
| -------------------------------- |
| |
| Standards like POSIX require that a libc provide certain library files like |
| ``libc.a``, ``libm.a``, etc. The targets for such library files are listed in |
| the ``lib`` directory as ``add_entrypoint_library`` targets. An |
| ``add_entrypoint_library`` target takes a list of ``add_entrypoint_object`` |
| targets and produces a static library containing the object files corresponding |
| to the ``add_entrypoint_targets``. |