face-valid-attribute-values

face-valid-attribute-values is a compiled Lisp function in `faces.el'.

(face-valid-attribute-values ATTRIBUTE &optional FRAME)

Return valid values for face attribute ATTRIBUTE.
The optional argument FRAME is used to determine available fonts
and colors. If it is nil or not specified, the selected frame is used.
Value is an alist of (NAME . VALUE) if ATTRIBUTE expects a value out
of a set of discrete values. Value is `integerp' if ATTRIBUTE expects
an integer value.