+The result of this macro is cached in the @code{ac_cv_working_alloca_h} +variable.That doesn't match our conventions, it seems like ac_cv_header_alloca_works might be nicer. If we document this one, we are stuck with the name.
I think we already are stuck with the existing names for all cache variables, especially because it would be a gratuitous incompatibility that autoupdate could not really help with.
Paolo
