vm.c: use `prepare_missing` in `mrb_funcall_with_block`

Remove code duplication.

src/vm.c

@@ -430,6 +430,52 @@ mrb_ci_nregs(mrb_callinfo *ci)
   return nregs;
 }
 
+mrb_value mrb_obj_missing(mrb_state *mrb, mrb_value mod);
+
+static mrb_method_t
+prepare_missing(mrb_state *mrb, mrb_value recv, mrb_sym mid, struct RClass **clsp, uint32_t a, uint16_t *c, mrb_value blk, int super)
+{
+  mrb_sym missing = MRB_SYM(method_missing);
+  mrb_callinfo *ci = mrb->c->ci;
+  uint16_t b = *c;
+  mrb_int n = b & 0xf;
+  mrb_int nk = (b>>4) & 0xf;
+  mrb_value *argv = &ci->stack[a+1];
+  mrb_value args;
+  mrb_method_t m;
+
+  /* pack positional arguments */
+  if (n == 15) args = argv[0];
+  else args = mrb_ary_new_from_values(mrb, n, argv);
+
+  if (mrb_func_basic_p(mrb, recv, missing, mrb_obj_missing)) {
+  method_missing:
+    if (super) mrb_no_method_error(mrb, mid, args, "no superclass method '%n'", mid);
+    else mrb_method_missing(mrb, mid, recv, args);
+    /* not reached */
+  }
+  if (mid != missing) {
+    *clsp = mrb_class(mrb, recv);
+  }
+  m = mrb_method_search_vm(mrb, clsp, missing);
+  if (MRB_METHOD_UNDEF_P(m)) goto method_missing; /* just in case */
+  mrb_stack_extend(mrb, a+4);
+
+  argv = &ci->stack[a+1];       /* maybe reallocated */
+  argv[0] = args;
+  if (nk == 0) {
+    argv[1] = blk;
+  }
+  else {
+    mrb_assert(nk == 15);
+    argv[1] = argv[n];
+    argv[2] = blk;
+  }
+  *c = 15 | (nk<<4);
+  mrb_ary_unshift(mrb, args, mrb_symbol_value(mid));
+  return m;
+}
+
 MRB_API mrb_value
 mrb_funcall_with_block(mrb_state *mrb, mrb_value self, mrb_sym mid, mrb_int argc, const mrb_value *argv, mrb_value blk)
 {
@@ -478,24 +524,15 @@ 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);
     mrb_stack_extend(mrb, n + argc + 3);
-    if (MRB_METHOD_UNDEF_P(m) || argc >= 15) {
-      mrb_value args = mrb_ary_new_from_values(mrb, argc, argv);
-
-      ci->stack[n+1] = args;
+    if (argc >= 15) {
+      ci->stack[n+1] = mrb_ary_new_from_values(mrb, argc, argv);
       argc = 15;
     }
     if (MRB_METHOD_UNDEF_P(m)) {
-      mrb_sym missing = MRB_SYM(method_missing);
-      mrb_value args = ci->stack[n+1];
-
-      m = mrb_method_search_vm(mrb, &c, missing);
-      if (MRB_METHOD_UNDEF_P(m)) {
-        mrb_method_missing(mrb, mid, self, args);
-      }
-      mrb_ary_unshift(mrb, args, mrb_symbol_value(mid));
-      mrb_stack_extend(mrb, n+2);
-      ci->stack[n+1] = args;
-      argc = 15;
+      uint16_t ac = (uint16_t)argc;
+      m = prepare_missing(mrb, self, mid, &c, n, &ac, mrb_nil_value(), 0);
+      argc = (mrb_int)ac;
+      mid = MRB_SYM(method_missing);
     }
     ci = cipush(mrb, n, 0, c, NULL, mid, argc);
     if (MRB_METHOD_PROC_P(m)) {
@@ -1123,52 +1160,6 @@ hash_new_from_values(mrb_state *mrb, mrb_int argc, mrb_value *regs)
   return hash;
 }
 
-mrb_value mrb_obj_missing(mrb_state *mrb, mrb_value mod);
-
-static mrb_method_t
-prepare_missing(mrb_state *mrb, mrb_value recv, mrb_sym mid, struct RClass **clsp, uint32_t a, uint16_t *c, mrb_value blk, int super)
-{
-  mrb_sym missing = MRB_SYM(method_missing);
-  mrb_callinfo *ci = mrb->c->ci;
-  uint16_t b = *c;
-  mrb_int n = b & 0xf;
-  mrb_int nk = (b>>4) & 0xf;
-  mrb_value *argv = &ci->stack[a+1];
-  mrb_value args;
-  mrb_method_t m;
-
-  /* pack positional arguments */
-  if (n == 15) args = argv[0];
-  else args = mrb_ary_new_from_values(mrb, n, argv);
-
-  if (mrb_func_basic_p(mrb, recv, missing, mrb_obj_missing)) {
-  method_missing:
-    if (super) mrb_no_method_error(mrb, mid, args, "no superclass method '%n'", mid);
-    else mrb_method_missing(mrb, mid, recv, args);
-    /* not reached */
-  }
-  if (mid != missing) {
-    *clsp = mrb_class(mrb, recv);
-  }
-  m = mrb_method_search_vm(mrb, clsp, missing);
-  if (MRB_METHOD_UNDEF_P(m)) goto method_missing; /* just in case */
-  mrb_stack_extend(mrb, a+4);
-
-  argv = &ci->stack[a+1];       /* maybe reallocated */
-  argv[0] = args;
-  if (nk == 0) {
-    argv[1] = blk;
-  }
-  else {
-    mrb_assert(nk == 15);
-    argv[1] = argv[n];
-    argv[2] = blk;
-  }
-  *c = 15 | (nk<<4);
-  mrb_ary_unshift(mrb, args, mrb_symbol_value(mid));
-  return m;
-}
-
 void mrb_method_added(mrb_state *mrb, struct RClass *c, mrb_sym mid);
 mrb_value mrb_str_aref(mrb_state *mrb, mrb_value str, mrb_value idx, mrb_value len);