+# (Re)generate include/usage.h
+src="$srctree/include/usage.src.h"
+dst="include/usage.h"
+# We add line continuation backslash after each line,
+# and insert empty line before each line which doesn't start
+# with space or tab
+# (note: we need to use \\\\ because of ``)
+s=`sed -n -e 's@^//usage:\([ \t].*\)$@\1 \\\\@p' -e 's@^//usage:\([^ \t].*\)$@\n\1 \\\\@p' -- "$srctree"/*/*.c "$srctree"/*/*/*.c`
+echo "/* DO NOT EDIT. This file is generated from usage.src.h */" >"$dst.$$.tmp"
+# Why "IFS='' read -r REPLY"??
+# This atrocity is needed to read lines without mangling.
+# IFS='' prevents whitespace trimming,
+# -r suppresses backslash handling.
+while IFS='' read -r REPLY; do
+ test x"$REPLY" = x"INSERT" && REPLY="$s"
+ printf "%s\n" "$REPLY"
+done <"$src" >>"$dst.$$.tmp"
+if test -f "$dst" && cmp -s "$dst.$$.tmp" "$dst"; then
+ rm -- "$dst.$$.tmp"
+else
+ echo " GEN $dst"
+ mv -- "$dst.$$.tmp" "$dst"
+fi
+