# CMAKE_<LANG>_FLAGS_INIT

Added in version 3.7.

Value used to initialize the `CMAKE_<LANG>_FLAGS` cache entry the first time a build tree is configured for language `<LANG>`. This variable is meant to be set by a `toolchain file`. CMake may prepend or append content to the value based on the environment and target platform. For example, the contents of a `xxxFLAGS` environment variable will be prepended, where `xxx` will be language-specific but not necessarily the same as `<LANG>` (e.g. `CXXFLAGS` for `CXX`, `FFLAGS` for `Fortran`, and so on). This value is a command-line string fragment. Therefore, multiple options should be separated by spaces, and options with spaces should be quoted.

See also the configuration-specific `CMAKE_<LANG>_FLAGS_<CONFIG>_INIT` variable.