uppercase_TABLE:=a,A b,B c,C d,D e,E f,F g,G h,H i,I j,J k,K l,L m,M n,N o,O p,P q,Q r,R s,S t,T u,U v,V w,W x,X y,Y z,Z

define uppercase_internal
$(if $1,$$(subst $(firstword $1),$(call uppercase_internal,$(wordlist
2,$(words $1),$1),$2)),$2)
endef

define uppercase
$(eval uppercase_RESULT:=$(call
uppercase_internal,$(uppercase_TABLE),$1))$(uppercase_RESULT)
endef