X-Git-Url: https://git.archive.openwrt.org/?p=openwrt.git;a=blobdiff_plain;f=include%2Fprereq.mk;h=4a55c89ffcf9afd115aab72f64d4973c64bfc674;hp=660f67cb1bb9349ef127bb7034aefbb5df1a8f9c;hb=48198491496a719dab3d0a0d6cb54153a7682898;hpb=196ad55bd2bdad8c5c86249afd4b1cec04855d35

diff --git a/include/prereq.mk b/include/prereq.mk
index 660f67cb1b..4a55c89ffc 100644
--- a/include/prereq.mk
+++ b/include/prereq.mk
@@ -5,6 +5,9 @@
 # See /LICENSE for more information.
 #
 
+ifneq ($(__prereq_inc),1)
+__prereq_inc:=1
+
 prereq:
 	if [ -f $(TMP_DIR)/.prereq-error ]; then \
 		echo; \
@@ -15,6 +18,7 @@ prereq:
 	fi
 
 .SILENT: prereq
+endif
 
 define Require
   export PREREQ_CHECK=1
@@ -47,4 +51,12 @@ define RequireCommand
   $$(eval $$(call Require,$(1),$(2)))
 endef
 
+define RequireHeader
+  define Require/$(1)
+    [ -e "$(1)" ]
+  endef
+  
+  $$(eval $$(call Require,$(1),$(2)))
+endef
+
 .NOTPARALLEL: