byte-compile-format-warn
byte-compile-format-warn is a compiled Lisp function in `bytecomp.el
'.
(byte-compile-format-warn FORM)
Warn if FORM is `format'-like with inconsistent args.
Applies if head of FORM is a symbol with non-nil property
`byte-compile-format-like' and first arg is a constant string.
Then check the number of format fields matches the number of
extra args.