make is built with support for GNU Guile as an embedded
extension language then the
guile function will be available.
guile function takes one argument which is first expanded
make in the normal fashion, then passed to the GNU Guile
evaluator. The result of the evaluator is converted into a string and
used as the expansion of the
guile function in the makefile.
See GNU Guile Integration for details on
writing extensions to
make in Guile.
You can determine whether GNU Guile support is available by checking
.FEATURES variable for the word guile.