# SWIFTC

Added in version 3.15.

This is a CMake Environment Variable. Its initial value is taken from the calling process environment.

Preferred executable for compiling `Swift` language files. Will only be used by CMake on the first configuration to determine `Swift` compiler, after which the value for `SWIFTC` is stored in the cache as `CMAKE_Swift_COMPILER`. For any configuration run (including the first), the environment variable will be ignored if the `CMAKE_Swift_COMPILER` variable is defined.

Note

Options that are required to make the compiler work correctly can be included; they can not be changed.

    $ export SWIFTC="custom-compiler --arg1 --arg2"