1 files changed, 9 insertions, 0 deletions
diff --git a/rules.mak b/rules.mak
index c843a131e8..6dac7773d5 100644
--- a/rules.mak
+++ b/rules.mak
@@ -42,6 +42,15 @@ cc-option = $(if $(shell $(CC) $1 $2 -S -o /dev/null -xc /dev/null \
 VPATH_SUFFIXES = %.c %.h %.S %.m %.mak %.texi
 set-vpath = $(if $1,$(foreach PATTERN,$(VPATH_SUFFIXES),$(eval vpath $(PATTERN) $1)))
 
+# find-in-path
+# Usage: $(call find-in-path, prog)
+# Looks in the PATH if the argument contains no slash, else only considers one
+# specific directory.  Returns an # empty string if the program doesn't exist
+# there.
+find-in-path = $(if $(find-string /, $1), \
+        $(wildcard $1), \
+        $(wildcard $(patsubst %, %/$1, $(subst :, ,$(PATH)))))
+
 # Generate timestamp files for .h include files
 
 %.h: %.h-timestamp