check-declare-scan is a compiled Lisp function in `check-declare.el'.

(check-declare-scan FILE)

Scan FILE for `declare-function' calls.
Return a list with elements of the form (FNFILE FN ARGLIST FILEONLY),
where only the first two elements need be present. This claims that FNFILE
defines FN, with ARGLIST. FILEONLY non-nil means only check that FNFILE
exists, not that it defines FN. This is for function definitions that we
don't know how to recognize (e.g. some macros).