sources := \
$(shell \
  for each in *.c; \
  do \
      echo $$each | sed -e 's, ,__whitespace__,g'; \
  done \
 )

objects := $(sources:.c=.o)

main: $(objects)
	gcc -o $@ $(^)

.PHONY: clean
clean: 
	rm -f $(objects) main

empty := 
space := $(empty) $(empty)
reconstitute = $(subst __whitespace__,\ ,$(1))
shell-escape = $(subst $(space),\ ,$(1))

$(foreach source,$(sources), \
  $(eval \
    $(source:.c=.o) : \
    $$(call reconstitute,$(source)) ; \
    gcc -c -o $$@ $$(call shell-escape,$$<) \
   ) \
 )