--- a/src/macros.h
+++ b/src/macros.h
@@ -253,3 +253,21 @@
 /* Without the 'numberwidth' option line numbers are always 7 chars. */
 # define number_width(x) 7
 #endif
+
+#ifndef FEAT_MBYTE
+# define after_pathsep(b, p) vim_ispathsep(*((p) - 1))
+#endif
+
+/*
+ * mb_ptr_adv(): advance a pointer to the next character, taking care of
+ * multi-byte characters if needed.
+ * mb_ptr_back(): backup a pointer to the previous character, taking care of
+ * multi-byte characters if needed.
+ */
+#ifdef FEAT_MBYTE
+# define mb_ptr_adv(p) p += has_mbyte ? (*mb_ptr2len_check)(p) : 1
+# define mb_ptr_back(s, p) p -= has_mbyte ? ((*mb_head_off)(s, p - 1) + 1) : 1
+#else
+# define mb_ptr_adv(p) ++p
+# define mb_ptr_back(s, p) --p
+#endif