Add `MRB_SYM()` for inline symbols.

12 files changed, 57 insertions, 57 deletions

diff --git a/src/array.c b/src/array.c
index c33641264..567ed7d8b 100644
--- a/src/array.c
+++ b/src/array.c
@@ -1312,11 +1312,11 @@ init_ary_each(mrb_state *mrb, struct RClass *ary)
 
   *each_irep = mrb_irep_zero;
   each_irep->syms = (mrb_sym*)mrb_malloc(mrb, sizeof(mrb_sym)*5);
-  each_irep->syms[0] = mrb_intern_lit(mrb, "each");
-  each_irep->syms[1] = mrb_intern_lit(mrb, "to_enum");
+  each_irep->syms[0] = MRB_SYM(each);
+  each_irep->syms[1] = MRB_SYM(to_enum);
   each_irep->syms[2] = mrb_intern_lit(mrb, "[]");
-  each_irep->syms[3] = mrb_intern_lit(mrb, "call");
-  each_irep->syms[4] = mrb_intern_lit(mrb, "length");
+  each_irep->syms[3] = MRB_SYM(call);
+  each_irep->syms[4] = MRB_SYM(length);
   each_irep->slen = 5;
   each_irep->flags = MRB_ISEQ_NO_FREE;
   each_irep->iseq = each_iseq;
@@ -1326,7 +1326,7 @@ init_ary_each(mrb_state *mrb, struct RClass *ary)
   p = mrb_proc_new(mrb, each_irep);
   p->flags |= MRB_PROC_SCOPE | MRB_PROC_STRICT;
   MRB_METHOD_FROM_PROC(m, p);
-  mrb_define_method_raw(mrb, ary, mrb_intern_lit(mrb, "each"), m);
+  mrb_define_method_raw(mrb, ary, MRB_SYM(each), m);
 }
 
 void
diff --git a/src/backtrace.c b/src/backtrace.c
index 591f4ea4b..b614a04be 100644
--- a/src/backtrace.c
+++ b/src/backtrace.c
@@ -114,7 +114,7 @@ mrb_print_backtrace(mrb_state *mrb)
     return;
   }
 
-  backtrace = mrb_obj_iv_get(mrb, mrb->exc, mrb_intern_lit(mrb, "backtrace"));
+  backtrace = mrb_obj_iv_get(mrb, mrb->exc, MRB_SYM(backtrace));
   if (mrb_nil_p(backtrace)) return;
   if (!mrb_array_p(backtrace)) backtrace = mrb_unpack_backtrace(mrb, backtrace);
   print_backtrace(mrb, mrb->exc, backtrace);
@@ -171,7 +171,7 @@ packed_backtrace(mrb_state *mrb)
 void
 mrb_keep_backtrace(mrb_state *mrb, mrb_value exc)
 {
-  mrb_sym sym = mrb_intern_lit(mrb, "backtrace");
+  mrb_sym sym = MRB_SYM(backtrace);
   mrb_value backtrace;
   int ai;
 
@@ -221,7 +221,7 @@ mrb_exc_backtrace(mrb_state *mrb, mrb_value exc)
   mrb_sym attr_name;
   mrb_value backtrace;
 
-  attr_name = mrb_intern_lit(mrb, "backtrace");
+  attr_name = MRB_SYM(backtrace);
   backtrace = mrb_iv_get(mrb, exc, attr_name);
   if (mrb_nil_p(backtrace) || mrb_array_p(backtrace)) {
     return backtrace;
diff --git a/src/class.c b/src/class.c
index fcbdadea8..465577e1a 100644
--- a/src/class.c
+++ b/src/class.c
@@ -58,7 +58,7 @@ void
 mrb_class_name_class(mrb_state *mrb, struct RClass *outer, struct RClass *c, mrb_sym id)
 {
   mrb_value name;
-  mrb_sym nsym = mrb_intern_lit(mrb, "__classname__");
+  mrb_sym nsym = MRB_SYM(__classname__);
 
   if (mrb_obj_iv_defined(mrb, (struct RObject*)c, nsym)) return;
   if (outer == NULL || outer == mrb->object_class) {
@@ -68,7 +68,7 @@ mrb_class_name_class(mrb_state *mrb, struct RClass *outer, struct RClass *c, mrb
     name = mrb_class_path(mrb, outer);
     if (mrb_nil_p(name)) {      /* unnamed outer class */
       if (outer != mrb->object_class && outer != c) {
-        mrb_obj_iv_set_force(mrb, (struct RObject*)c, mrb_intern_lit(mrb, "__outer__"),
+        mrb_obj_iv_set_force(mrb, (struct RObject*)c, MRB_SYM(__outer__),
                              mrb_obj_value(outer));
       }
       return;
@@ -132,7 +132,7 @@ prepare_singleton_class(mrb_state *mrb, struct RBasic *o)
   o->c = sc;
   mrb_field_write_barrier(mrb, (struct RBasic*)o, (struct RBasic*)sc);
   mrb_field_write_barrier(mrb, (struct RBasic*)sc, (struct RBasic*)o);
-  mrb_obj_iv_set(mrb, (struct RObject*)sc, mrb_intern_lit(mrb, "__attached__"), mrb_obj_value(o));
+  mrb_obj_iv_set(mrb, (struct RObject*)sc, MRB_SYM(__attached__), mrb_obj_value(o));
   sc->flags |= o->flags & MRB_FL_OBJ_IS_FROZEN;
 }
 
@@ -302,7 +302,7 @@ mrb_class_inherited(mrb_state *mrb, struct RClass *super, struct RClass *klass)
   super->flags |= MRB_FL_CLASS_IS_INHERITED;
   s = mrb_obj_value(super);
   mrb_mc_clear_by_class(mrb, klass);
-  mid = mrb_intern_lit(mrb, "inherited");
+  mid = MRB_SYM(inherited);
   if (!mrb_func_basic_p(mrb, s, mid, mrb_bob_init)) {
     mrb_value c = mrb_obj_value(klass);
     mrb_funcall_argv(mrb, s, mid, 1, &c);
@@ -1578,7 +1578,7 @@ mrb_instance_new(mrb_state *mrb, mrb_value cv)
 
   mrb_get_args(mrb, "*!&", &argv, &argc, &blk);
   obj = mrb_instance_alloc(mrb, cv);
-  init = mrb_intern_lit(mrb, "initialize");
+  init = MRB_SYM(initialize);
   if (!mrb_func_basic_p(mrb, obj, init, mrb_bob_init)) {
     mrb_funcall_with_block(mrb, obj, init, argc, argv, blk);
   }
@@ -1592,7 +1592,7 @@ mrb_obj_new(mrb_state *mrb, struct RClass *c, mrb_int argc, const mrb_value *arg
   mrb_sym mid;
 
   obj = mrb_instance_alloc(mrb, mrb_obj_value(c));
-  mid = mrb_intern_lit(mrb, "initialize");
+  mid = MRB_SYM(initialize);
   if (!mrb_func_basic_p(mrb, obj, mid, mrb_bob_init)) {
     mrb_funcall_argv(mrb, obj, mid, argc, argv);
   }
@@ -1624,7 +1624,7 @@ mrb_class_new_class(mrb_state *mrb, mrb_value cv)
     super = mrb_obj_value(mrb->object_class);
   }
   new_class = mrb_obj_value(mrb_class_new(mrb, mrb_class_ptr(super)));
-  mid = mrb_intern_lit(mrb, "initialize");
+  mid = MRB_SYM(initialize);
   if (mrb_func_basic_p(mrb, new_class, mid, mrb_class_initialize)) {
     mrb_class_initialize(mrb, new_class);
   }
@@ -1722,7 +1722,7 @@ MRB_API mrb_value
 mrb_class_path(mrb_state *mrb, struct RClass *c)
 {
   mrb_value path;
-  mrb_sym nsym = mrb_intern_lit(mrb, "__classname__");
+  mrb_sym nsym = MRB_SYM(__classname__);
 
   path = mrb_obj_iv_get(mrb, (struct RObject*)c, nsym);
   if (mrb_nil_p(path)) {
@@ -1891,7 +1891,7 @@ mrb_mod_to_s(mrb_state *mrb, mrb_value klass)
 {
 
   if (mrb_sclass_p(klass)) {
-    mrb_value v = mrb_iv_get(mrb, klass, mrb_intern_lit(mrb, "__attached__"));
+    mrb_value v = mrb_iv_get(mrb, klass, MRB_SYM(__attached__));
     mrb_value str = mrb_str_new_lit(mrb, "#<Class:");
 
     if (class_ptr_p(v)) {
@@ -2239,8 +2239,8 @@ init_class_new(mrb_state *mrb, struct RClass *cls)
 
   *new_irep = mrb_irep_zero;
   new_irep->syms = (mrb_sym*)mrb_malloc(mrb, sizeof(mrb_sym)*2);
-  new_irep->syms[0] = mrb_intern_lit(mrb, "allocate");
-  new_irep->syms[1] = mrb_intern_lit(mrb, "initialize");
+  new_irep->syms[0] = MRB_SYM(allocate);
+  new_irep->syms[1] = MRB_SYM(initialize);
   new_irep->slen = 2;
   new_irep->flags = MRB_ISEQ_NO_FREE;
   new_irep->iseq = new_iseq;
@@ -2249,7 +2249,7 @@ init_class_new(mrb_state *mrb, struct RClass *cls)
   new_irep->nlocals = 3;
   p = mrb_proc_new(mrb, new_irep);
   MRB_METHOD_FROM_PROC(m, p);
-  mrb_define_method_raw(mrb, cls, mrb_intern_lit(mrb, "new"), m);
+  mrb_define_method_raw(mrb, cls, MRB_SYM(new), m);
 }
 
 void
@@ -2279,10 +2279,10 @@ mrb_init_class(mrb_state *mrb)
   mrb_define_const(mrb, obj, "Class",       mrb_obj_value(cls));
 
   /* name each classes */
-  mrb_class_name_class(mrb, NULL, bob, mrb_intern_lit(mrb, "BasicObject"));
-  mrb_class_name_class(mrb, NULL, obj, mrb_intern_lit(mrb, "Object")); /* 15.2.1 */
-  mrb_class_name_class(mrb, NULL, mod, mrb_intern_lit(mrb, "Module")); /* 15.2.2 */
-  mrb_class_name_class(mrb, NULL, cls, mrb_intern_lit(mrb, "Class"));  /* 15.2.3 */
+  mrb_class_name_class(mrb, NULL, bob, MRB_SYM(BasicObject));
+  mrb_class_name_class(mrb, NULL, obj, MRB_SYM(Object)); /* 15.2.1 */
+  mrb_class_name_class(mrb, NULL, mod, MRB_SYM(Module)); /* 15.2.2 */
+  mrb_class_name_class(mrb, NULL, cls, MRB_SYM(Class));  /* 15.2.3 */
 
   mrb->proc_class = mrb_define_class(mrb, "Proc", mrb->object_class);  /* 15.2.17 */
   MRB_SET_INSTANCE_TT(mrb->proc_class, MRB_TT_PROC);
diff --git a/src/error.c b/src/error.c
index 5d17209e5..30835e206 100644
--- a/src/error.c
+++ b/src/error.c
@@ -45,7 +45,7 @@ exc_initialize(mrb_state *mrb, mrb_value exc)
   mrb_value mesg;
 
   if (mrb_get_args(mrb, "|o", &mesg) == 1) {
-    mrb_iv_set(mrb, exc, mrb_intern_lit(mrb, "mesg"), mesg);
+    mrb_iv_set(mrb, exc, MRB_SYM(mesg), mesg);
   }
   return exc;
 }
@@ -74,7 +74,7 @@ exc_exception(mrb_state *mrb, mrb_value self)
   if (argc == 0) return self;
   if (mrb_obj_equal(mrb, self, a)) return self;
   exc = mrb_obj_clone(mrb, self);
-  mrb_iv_set(mrb, exc, mrb_intern_lit(mrb, "mesg"), a);
+  mrb_iv_set(mrb, exc, MRB_SYM(mesg), a);
 
   return exc;
 }
@@ -90,7 +90,7 @@ exc_exception(mrb_state *mrb, mrb_value self)
 mrb_value
 exc_to_s(mrb_state *mrb, mrb_value exc)
 {
-  mrb_value mesg = mrb_attr_get(mrb, exc, mrb_intern_lit(mrb, "mesg"));
+  mrb_value mesg = mrb_attr_get(mrb, exc, MRB_SYM(mesg));
   struct RObject *p;
 
   if (!mrb_string_p(mesg)) {
@@ -130,7 +130,7 @@ exc_message(mrb_state *mrb, mrb_value exc)
 mrb_value
 mrb_exc_inspect(mrb_state *mrb, mrb_value exc)
 {
-  mrb_value mesg = mrb_attr_get(mrb, exc, mrb_intern_lit(mrb, "mesg"));
+  mrb_value mesg = mrb_attr_get(mrb, exc, MRB_SYM(mesg));
   mrb_value cname = mrb_mod_to_s(mrb, mrb_obj_value(mrb_obj_class(mrb, exc)));
   mesg = mrb_obj_as_string(mrb, mesg);
   return RSTRING_LEN(mesg) == 0 ? cname : mrb_format(mrb, "%v (%v)", mesg, cname);
@@ -154,7 +154,7 @@ set_backtrace(mrb_state *mrb, mrb_value exc, mrb_value backtrace)
       p++;
     }
   }
-  mrb_iv_set(mrb, exc, mrb_intern_lit(mrb, "backtrace"), backtrace);
+  mrb_iv_set(mrb, exc, MRB_SYM(backtrace), backtrace);
 }
 
 static mrb_value
@@ -474,7 +474,7 @@ mrb_make_exception(mrb_state *mrb, mrb_int argc, const mrb_value *argv)
       n = 1;
 exception_call:
       {
-        mrb_sym exc = mrb_intern_lit(mrb, "exception");
+        mrb_sym exc = MRB_SYM(exception);
         if (mrb_respond_to(mrb, argv[0], exc)) {
           mesg = mrb_funcall_argv(mrb, argv[0], exc, n, argv+1);
         }
diff --git a/src/hash.c b/src/hash.c
index c891e1b22..a9ac79226 100644
--- a/src/hash.c
+++ b/src/hash.c
@@ -683,7 +683,7 @@ mrb_hash_init_copy(mrb_state *mrb, mrb_value self)
   vret = mrb_obj_value(copy);
   ifnone = RHASH_IFNONE(self);
   if (!mrb_nil_p(ifnone)) {
-      mrb_iv_set(mrb, vret, mrb_intern_lit(mrb, "ifnone"), ifnone);
+    mrb_iv_set(mrb, vret, MRB_SYM(ifnone), ifnone);
   }
   return vret;
 }
@@ -729,7 +729,7 @@ mrb_hash_get(mrb_state *mrb, mrb_value hash, mrb_value key)
     return val;
   }
 
-  mid = mrb_intern_lit(mrb, "default");
+  mid = MRB_SYM(default);
   if (mrb_func_basic_p(mrb, hash, mid, mrb_hash_default)) {
     return hash_default(mrb, hash, key);
   }
@@ -824,7 +824,7 @@ mrb_hash_init(mrb_state *mrb, mrb_value hash)
   }
   if (!mrb_nil_p(ifnone)) {
     RHASH(hash)->flags |= MRB_HASH_DEFAULT;
-    mrb_iv_set(mrb, hash, mrb_intern_lit(mrb, "ifnone"), ifnone);
+    mrb_iv_set(mrb, hash, MRB_SYM(ifnone), ifnone);
   }
   return hash;
 }
@@ -933,7 +933,7 @@ mrb_hash_set_default(mrb_state *mrb, mrb_value hash)
   mrb_value ifnone = mrb_get_arg1(mrb);
 
   mrb_hash_modify(mrb, hash);
-  mrb_iv_set(mrb, hash, mrb_intern_lit(mrb, "ifnone"), ifnone);
+  mrb_iv_set(mrb, hash, MRB_SYM(ifnone), ifnone);
   RHASH(hash)->flags &= ~MRB_HASH_PROC_DEFAULT;
   if (!mrb_nil_p(ifnone)) {
     RHASH(hash)->flags |= MRB_HASH_DEFAULT;
@@ -988,7 +988,7 @@ mrb_hash_set_default_proc(mrb_state *mrb, mrb_value hash)
   mrb_value ifnone = mrb_get_arg1(mrb);
 
   mrb_hash_modify(mrb, hash);
-  mrb_iv_set(mrb, hash, mrb_intern_lit(mrb, "ifnone"), ifnone);
+  mrb_iv_set(mrb, hash, MRB_SYM(ifnone), ifnone);
   if (!mrb_nil_p(ifnone)) {
     RHASH(hash)->flags |= MRB_HASH_PROC_DEFAULT;
     RHASH(hash)->flags |= MRB_HASH_DEFAULT;
diff --git a/src/kernel.c b/src/kernel.c
index 10ed9f88e..e192ed752 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -33,7 +33,7 @@ mrb_func_basic_p(mrb_state *mrb, mrb_value obj, mrb_sym mid, mrb_func_t func)
 static mrb_bool
 mrb_obj_basic_to_s_p(mrb_state *mrb, mrb_value obj)
 {
-  return mrb_func_basic_p(mrb, obj, mrb_intern_lit(mrb, "to_s"), mrb_any_to_s);
+  return mrb_func_basic_p(mrb, obj, MRB_SYM(to_s), mrb_any_to_s);
 }
 
 /* 15.3.1.3.17 */
@@ -240,7 +240,7 @@ mrb_singleton_class_clone(mrb_state *mrb, mrb_value obj)
     clone->super = klass->super;
     if (klass->iv) {
       mrb_iv_copy(mrb, mrb_obj_value(clone), mrb_obj_value(klass));
-      mrb_obj_iv_set(mrb, (struct RObject*)clone, mrb_intern_lit(mrb, "__attached__"), obj);
+      mrb_obj_iv_set(mrb, (struct RObject*)clone, MRB_SYM(__attached__), obj);
     }
     if (klass->mt) {
       clone->mt = kh_copy(mt, mrb, klass->mt);
@@ -294,7 +294,7 @@ init_copy(mrb_state *mrb, mrb_value dest, mrb_value obj)
     case MRB_TT_MODULE:
       copy_class(mrb, dest, obj);
       mrb_iv_copy(mrb, dest, obj);
-      mrb_iv_remove(mrb, dest, mrb_intern_lit(mrb, "__classname__"));
+      mrb_iv_remove(mrb, dest, MRB_SYM(__classname__));
       break;
     case MRB_TT_OBJECT:
     case MRB_TT_SCLASS:
diff --git a/src/print.c b/src/print.c
index a75814d81..6bf7da6a5 100644
--- a/src/print.c
+++ b/src/print.c
@@ -60,11 +60,11 @@ mrb_print_error(mrb_state *mrb)
 MRB_API void
 mrb_show_version(mrb_state *mrb)
 {
-  printstr(mrb_const_get(mrb, mrb_obj_value(mrb->object_class), mrb_intern_lit(mrb, "MRUBY_DESCRIPTION")), stdout);
+  printstr(mrb_const_get(mrb, mrb_obj_value(mrb->object_class), MRB_SYM(MRUBY_DESCRIPTION)), stdout);
 }
 
 MRB_API void
 mrb_show_copyright(mrb_state *mrb)
 {
-  printstr(mrb_const_get(mrb, mrb_obj_value(mrb->object_class), mrb_intern_lit(mrb, "MRUBY_COPYRIGHT")), stdout);
+  printstr(mrb_const_get(mrb, mrb_obj_value(mrb->object_class), MRB_SYM(MRUBY_COPYRIGHT)), stdout);
 }
diff --git a/src/proc.c b/src/proc.c
index c00b09acf..743e9610c 100644
--- a/src/proc.c
+++ b/src/proc.c
@@ -200,7 +200,7 @@ mrb_proc_s_new(mrb_state *mrb, mrb_value proc_class)
   p = (struct RProc *)mrb_obj_alloc(mrb, MRB_TT_PROC, mrb_class_ptr(proc_class));
   mrb_proc_copy(p, mrb_proc_ptr(blk));
   proc = mrb_obj_value(p);
-  mrb_funcall_with_block(mrb, proc, mrb_intern_lit(mrb, "initialize"), 0, NULL, proc);
+  mrb_funcall_with_block(mrb, proc, MRB_SYM(initialize), 0, NULL, proc);
   if (!MRB_PROC_STRICT_P(p) &&
       mrb->c->ci > mrb->c->cibase && MRB_PROC_ENV(p) == mrb->c->ci[-1].env) {
     p->flags |= MRB_PROC_ORPHAN;
@@ -325,7 +325,7 @@ mrb_init_proc(mrb_state *mrb)
   p = mrb_proc_new(mrb, call_irep);
   irep_obj->data = NULL;
   MRB_METHOD_FROM_PROC(m, p);
-  mrb_define_method_raw(mrb, mrb->proc_class, mrb_intern_lit(mrb, "call"), m);
+  mrb_define_method_raw(mrb, mrb->proc_class, MRB_SYM(call), m);
   mrb_define_method_raw(mrb, mrb->proc_class, mrb_intern_lit(mrb, "[]"), m);
 
   mrb_define_class_method(mrb, mrb->kernel_module, "lambda", proc_lambda, MRB_ARGS_NONE()|MRB_ARGS_BLOCK()); /* 15.3.1.2.6  */
diff --git a/src/range.c b/src/range.c
index 0b4e6dbca..868d3d397 100644
--- a/src/range.c
+++ b/src/range.c
@@ -78,7 +78,7 @@ range_ptr_init(mrb_state *mrb, struct RRange *r, mrb_value beg, mrb_value end, m
   if (r) {
     if (RANGE_INITIALIZED_P(r)) {
       /* Ranges are immutable, so that they should be initialized only once. */
-      mrb_name_error(mrb, mrb_intern_lit(mrb, "initialize"), "'initialize' called twice");
+      mrb_name_error(mrb, MRB_SYM(initialize), "'initialize' called twice");
     }
     else {
       range_ptr_alloc_edges(mrb, r);
diff --git a/src/symbol.c b/src/symbol.c
index a78dd5f4c..a09298b23 100644
--- a/src/symbol.c
+++ b/src/symbol.c
@@ -13,6 +13,8 @@
 #include <mruby/class.h>
 
 #undef MRB_PRESYM_MAX
+#undef MRB_PRESYM_CSYM
+#undef MRB_PRESYM_SYM
 #define MRB_PRESYM_CSYM(sym, num) #sym,
 #define MRB_PRESYM_SYM(sym, num) #sym,
 
diff --git a/src/variable.c b/src/variable.c
index c36fea6e3..add1155c8 100644
--- a/src/variable.c
+++ b/src/variable.c
@@ -379,11 +379,11 @@ assign_class_name(mrb_state *mrb, struct RObject *obj, mrb_sym sym, mrb_value v)
   if (namespace_p(obj->tt) && namespace_p(mrb_type(v))) {
     struct RObject *c = mrb_obj_ptr(v);
     if (obj != c && ISUPPER(mrb_sym_name_len(mrb, sym, NULL)[0])) {
-      mrb_sym id_classname = mrb_intern_lit(mrb, "__classname__");
+      mrb_sym id_classname = MRB_SYM(__classname__);
       mrb_value o = mrb_obj_iv_get(mrb, c, id_classname);
 
       if (mrb_nil_p(o)) {
-        mrb_sym id_outer = mrb_intern_lit(mrb, "__outer__");
+        mrb_sym id_outer = MRB_SYM(__outer__);
         o = mrb_obj_iv_get(mrb, c, id_outer);
 
         if (mrb_nil_p(o)) {
@@ -643,8 +643,7 @@ mrb_mod_cv_get(mrb_state *mrb, struct RClass *c, mrb_sym sym)
   if (cls && cls->tt == MRB_TT_SCLASS) {
     mrb_value klass;
 
-    klass = mrb_obj_iv_get(mrb, (struct RObject *)cls,
-                           mrb_intern_lit(mrb, "__attached__"));
+    klass = mrb_obj_iv_get(mrb, (struct RObject *)cls, MRB_SYM(__attached__));
     c = mrb_class_ptr(klass);
     if (c->tt == MRB_TT_CLASS || c->tt == MRB_TT_MODULE) {
       given = FALSE;
@@ -688,8 +687,7 @@ mrb_mod_cv_set(mrb_state *mrb, struct RClass *c, mrb_sym sym, mrb_value v)
   if (cls && cls->tt == MRB_TT_SCLASS) {
     mrb_value klass;
 
-    klass = mrb_obj_iv_get(mrb, (struct RObject*)cls,
-                           mrb_intern_lit(mrb, "__attached__"));
+    klass = mrb_obj_iv_get(mrb, (struct RObject*)cls, MRB_SYM(__attached__));
     switch (mrb_type(klass)) {
     case MRB_TT_CLASS:
     case MRB_TT_MODULE:
@@ -803,7 +801,7 @@ L_RETRY:
     goto L_RETRY;
   }
   name = mrb_symbol_value(sym);
-  return mrb_funcall_argv(mrb, mrb_obj_value(base), mrb_intern_lit(mrb, "const_missing"), 1, &name);
+  return mrb_funcall_argv(mrb, mrb_obj_value(base), MRB_SYM(const_missing), 1, &name);
 }
 
 MRB_API mrb_value
@@ -829,7 +827,7 @@ mrb_vm_const_get(mrb_state *mrb, mrb_sym sym)
   while (c2 && c2->tt == MRB_TT_SCLASS) {
     mrb_value klass;
 
-    if (!iv_get(mrb, c2->iv, mrb_intern_lit(mrb, "__attached__"), &klass)) {
+    if (!iv_get(mrb, c2->iv, MRB_SYM(__attached__), &klass)) {
       c2 = NULL;
       break;
     }
@@ -1070,7 +1068,7 @@ outer_class(mrb_state *mrb, struct RClass *c)
 {
   mrb_value ov;
 
-  ov = mrb_obj_iv_get(mrb, (struct RObject*)c, mrb_intern_lit(mrb, "__outer__"));
+  ov = mrb_obj_iv_get(mrb, (struct RObject*)c, MRB_SYM(__outer__));
   if (mrb_nil_p(ov)) return NULL;
   switch (mrb_type(ov)) {
   case MRB_TT_CLASS:
@@ -1120,8 +1118,8 @@ mrb_class_find_path(mrb_state *mrb, struct RClass *c)
   str = mrb_sym_name_len(mrb, name, &len);
   mrb_str_cat(mrb, path, str, len);
   if (RSTRING_PTR(path)[0] != '#') {
-    iv_del(mrb, c->iv, mrb_intern_lit(mrb, "__outer__"), NULL);
-    iv_put(mrb, c->iv, mrb_intern_lit(mrb, "__classname__"), path);
+    iv_del(mrb, c->iv, MRB_SYM(__outer__), NULL);
+    iv_put(mrb, c->iv, MRB_SYM(__classname__), path);
     mrb_field_write_barrier_value(mrb, (struct RBasic*)c, path);
     path = mrb_str_dup(mrb, path);
   }
diff --git a/src/vm.c b/src/vm.c
index cc9a187b7..d032f2794 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -467,7 +467,7 @@ mrb_funcall_with_block(mrb_state *mrb, mrb_value self, mrb_sym mid, mrb_int argc
     c = mrb_class(mrb, self);
     m = mrb_method_search_vm(mrb, &c, mid);
     if (MRB_METHOD_UNDEF_P(m)) {
-      mrb_sym missing = mrb_intern_lit(mrb, "method_missing");
+      mrb_sym missing = MRB_SYM(method_missing);
       mrb_value args = mrb_ary_new_from_values(mrb, argc, argv);
       m = mrb_method_search_vm(mrb, &c, missing);
       if (MRB_METHOD_UNDEF_P(m)) {
@@ -1364,7 +1364,7 @@ RETRY_TRY_BLOCK:
       cls = mrb_class(mrb, recv);
       m = mrb_method_search_vm(mrb, &cls, mid);
       if (MRB_METHOD_UNDEF_P(m)) {
-        mrb_sym missing = mrb_intern_lit(mrb, "method_missing");
+        mrb_sym missing = MRB_SYM(method_missing);
         m = mrb_method_search_vm(mrb, &cls, missing);
         if (MRB_METHOD_UNDEF_P(m) || (missing == mrb->c->ci->mid && mrb_obj_eq(mrb, regs[0], recv))) {
           mrb_value args = (argc < 0) ? regs[a+1] : mrb_ary_new_from_values(mrb, c, regs+a+1);
@@ -1547,7 +1547,7 @@ RETRY_TRY_BLOCK:
       cls = target_class->super;
       m = mrb_method_search_vm(mrb, &cls, mid);
       if (MRB_METHOD_UNDEF_P(m)) {
-        mrb_sym missing = mrb_intern_lit(mrb, "method_missing");
+        mrb_sym missing = MRB_SYM(method_missing);
 
         if (mid != missing) {
           cls = mrb_class(mrb, recv);