Config.mk: expand cc-ver a bit

... so that we can do other comparisons as well.

No functional change.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

Config.mk

@@ -113,17 +113,17 @@ endef
 
 cc-options-add = $(foreach o,$(3),$(call cc-option-add,$(1),$(2),$(o)))
 
-# cc-ver: Check compiler is at least specified version. Return boolean 'y'/'n'.
-# Usage: ifeq ($(call cc-ver,$(CC),0x030400),y)
+# cc-ver: Check compiler against the version requirement. Return boolean 'y'/'n'.
+# Usage: ifeq ($(call cc-ver,$(CC),ge,0x030400),y)
 cc-ver = $(shell if [ $$((`$(1) -dumpversion | awk -F. \
-           '{ printf "0x%02x%02x%02x", $$1, $$2, $$3}'`)) -ge $$(($(2))) ]; \
+           '{ printf "0x%02x%02x%02x", $$1, $$2, $$3}'`)) -$(2) $$(($(3))) ]; \
            then echo y; else echo n; fi ;)
 
 # cc-ver-check: Check compiler is at least specified version, else fail.
 # Usage: $(call cc-ver-check,CC,0x030400,"Require at least gcc-3.4")
 cc-ver-check = $(eval $(call cc-ver-check-closure,$(1),$(2),$(3)))
 define cc-ver-check-closure
-    ifeq ($$(call cc-ver,$$($(1)),$(2)),n)
+    ifeq ($$(call cc-ver,$$($(1)),ge,$(2)),n)
         override $(1) = echo "*** FATAL BUILD ERROR: "$(3) >&2; exit 1;
         cc-option := n
     endif