mrb_str_strlen() should be MRB_API; ref #3216

include/mruby/string.h

@@ -76,7 +76,7 @@ struct RString {
 #define RSTRING_LEN(s)       RSTR_LEN(RSTRING(s))
 #define RSTRING_CAPA(s)      RSTR_CAPA(RSTRING(s))
 #define RSTRING_END(s)       (RSTRING_PTR(s) + RSTRING_LEN(s))
-mrb_int mrb_str_strlen(mrb_state*, struct RString*);
+MRB_API mrb_int mrb_str_strlen(mrb_state*, struct RString*);
 
 #define MRB_STR_SHARED    1
 #define MRB_STR_NOFREE    2

src/string.c

@@ -576,7 +576,7 @@ str_rindex(mrb_state *mrb, mrb_value str, mrb_value sub, mrb_int pos)
   }
 }
 
-mrb_int
+MRB_API mrb_int
 mrb_str_strlen(mrb_state *mrb, struct RString *s)
 {
   mrb_int i, max = RSTR_LEN(s);