Read/write `MRB_STR_ASCII` flag only when `MRB_UTF8_STRING` is defined

include/mruby/string.h

@@ -68,6 +68,20 @@ struct RString {
 #define RSTR_SET_NOFREE_FLAG(s) ((s)->flags |= MRB_STR_NOFREE)
 #define RSTR_UNSET_NOFREE_FLAG(s) ((s)->flags &= ~MRB_STR_NOFREE)
 
+#ifdef MRB_UTF8_STRING
+# define RSTR_ASCII_P(s) ((s)->flags & MRB_STR_ASCII)
+# define RSTR_SET_ASCII_FLAG(s) ((s)->flags |= MRB_STR_ASCII)
+# define RSTR_UNSET_ASCII_FLAG(s) ((s)->flags &= ~MRB_STR_ASCII)
+# define RSTR_WRITE_ASCII_FLAG(s, v) (RSTR_UNSET_ASCII_FLAG(s), (s)->flags |= v)
+# define RSTR_COPY_ASCII_FLAG(dst, src) RSTR_WRITE_ASCII_FLAG(dst, RSTR_ASCII_P(src))
+#else
+# define RSTR_ASCII_P(s) (void)0
+# define RSTR_SET_ASCII_FLAG(s) (void)0
+# define RSTR_UNSET_ASCII_FLAG(s) (void)0
+# define RSTR_WRITE_ASCII_FLAG(s, v) (void)0
+# define RSTR_COPY_ASCII_FLAG(dst, src) (void)0
+#endif
+
 #define RSTR_POOL_P(s) ((s)->flags & MRB_STR_POOL)
 #define RSTR_SET_POOL_FLAG(s) ((s)->flags |= MRB_STR_POOL)
 

src/string.c

@@ -258,14 +258,15 @@ mrb_utf8_len(const char *str, mrb_int byte_len)
 static mrb_int
 utf8_strlen(mrb_value str)
 {
-  mrb_int byte_len = RSTRING_LEN(str);
+  struct RString *s = mrb_str_ptr(str);
+  mrb_int byte_len = RSTR_LEN(s);
 
-  if (RSTRING(str)->flags & MRB_STR_ASCII) {
+  if (RSTR_ASCII_P(s)) {
     return byte_len;
   }
   else {
-    mrb_int utf8_len = mrb_utf8_len(RSTRING_PTR(str), byte_len);
-    if (byte_len == utf8_len) RSTRING(str)->flags |= MRB_STR_ASCII;
+    mrb_int utf8_len = mrb_utf8_len(RSTR_PTR(s), byte_len);
+    if (byte_len == utf8_len) RSTR_SET_ASCII_FLAG(s);
     return utf8_len;
   }
 }
@@ -512,8 +513,7 @@ str_replace(mrb_state *mrb, struct RString *s1, struct RString *s2)
 
   mrb_check_frozen(mrb, s1);
   if (s1 == s2) return mrb_obj_value(s1);
-  s1->flags &= ~MRB_STR_ASCII;
-  s1->flags |= s2->flags&MRB_STR_ASCII;
+  RSTR_COPY_ASCII_FLAG(s1, s2);
   len = RSTR_LEN(s2);
   if (RSTR_SHARED_P(s1)) {
     str_decref(mrb, s1->as.heap.aux.shared);
@@ -651,7 +651,7 @@ MRB_API void
 mrb_str_modify(mrb_state *mrb, struct RString *s)
 {
   mrb_check_frozen(mrb, s);
-  s->flags &= ~MRB_STR_ASCII;
+  RSTR_UNSET_ASCII_FLAG(s);
   if (RSTR_SHARED_P(s)) {
     mrb_shared_string *shared = s->as.heap.aux.shared;