CMake: conditional and logical expression syntax.06 Dec 2022
Mostly a page with a link – the reference page for
if() and logical expressions is here, from CMake’s docs.
Of note –
endif() require parentheses. It is not required to place anything inside the parentheses.
Per legacy, the else() and endif() commands admit an optional
argument. If used, it must be a verbatim repeat of the argument of the opening if command.