refactor mrb_bob_missing to share raising NoMethodError code; fix #2878

Note: arguments of mrb_no_method_error() has changed. You need to replace
3rd and 4th argument (say n, argv) to mrb_ary_new_from_values(mrb, n, argv).

include/mruby/error.h

@@ -24,7 +24,7 @@ MRB_API mrb_value mrb_exc_new_str(mrb_state *mrb, struct RClass* c, mrb_value st
 MRB_API mrb_value mrb_make_exception(mrb_state *mrb, int argc, const mrb_value *argv);
 MRB_API mrb_value mrb_exc_backtrace(mrb_state *mrb, mrb_value exc);
 MRB_API mrb_value mrb_get_backtrace(mrb_state *mrb);
-MRB_API mrb_noreturn void mrb_no_method_error(mrb_state *mrb, mrb_sym id, mrb_int argc, const mrb_value *argv, const char *fmt, ...);
+MRB_API mrb_noreturn void mrb_no_method_error(mrb_state *mrb, mrb_sym id, mrb_value args, const char *fmt, ...);
 
 /* declaration for fail method */
 MRB_API mrb_value mrb_f_raise(mrb_state*, mrb_value);

src/class.c

@@ -1262,6 +1262,31 @@ mrb_bob_not(mrb_state *mrb, mrb_value cv)
   return mrb_bool_value(!mrb_test(cv));
 }
 
+void
+mrb_method_missing(mrb_state *mrb, mrb_sym name, mrb_value self, mrb_value args)
+{
+  mrb_sym inspect;
+  mrb_value repr;
+
+  inspect = mrb_intern_lit(mrb, "inspect");
+  if (mrb->c->ci > mrb->c->cibase && mrb->c->ci[-1].mid == inspect) {
+    /* method missing in inspect; avoid recursion */
+    repr = mrb_any_to_s(mrb, self);
+  }
+  else if (mrb_respond_to(mrb, self, inspect) && mrb->c->ci - mrb->c->cibase < 64) {
+    repr = mrb_funcall_argv(mrb, self, inspect, 0, 0);
+    if (mrb_string_p(repr) && RSTRING_LEN(repr) > 64) {
+      repr = mrb_any_to_s(mrb, self);
+    }
+  }
+  else {
+    repr = mrb_any_to_s(mrb, self);
+  }
+
+  mrb_no_method_error(mrb, name, args, "undefined method '%S' for %S",
+                      mrb_sym2str(mrb, name), repr);
+}
+
 /* 15.3.1.3.30 */
 /*
  *  call-seq:
@@ -1301,27 +1326,9 @@ mrb_bob_missing(mrb_state *mrb, mrb_value mod)
   mrb_sym name;
   mrb_value *a;
   mrb_int alen;
-  mrb_sym inspect;
-  mrb_value repr;
 
   mrb_get_args(mrb, "n*", &name, &a, &alen);
-
-  inspect = mrb_intern_lit(mrb, "inspect");
-  if (mrb->c->ci > mrb->c->cibase && mrb->c->ci[-1].mid == inspect) {
-    /* method missing in inspect; avoid recursion */
-    repr = mrb_any_to_s(mrb, mod);
-  }
-  else if (mrb_respond_to(mrb, mod, inspect) && mrb->c->ci - mrb->c->cibase < 64) {
-    repr = mrb_funcall_argv(mrb, mod, inspect, 0, 0);
-    if (mrb_string_p(repr) && RSTRING_LEN(repr) > 64) {
-      repr = mrb_any_to_s(mrb, mod);
-    }
-  }
-  else {
-    repr = mrb_any_to_s(mrb, mod);
-  }
-
-  mrb_no_method_error(mrb, name, alen, a, "undefined method '%S' for %S", mrb_sym2str(mrb, name), repr);
+  mrb_method_missing(mrb, name, mod, mrb_ary_new_from_values(mrb, alen, a));
   /* not reached */
   return mrb_nil_value();
 }

src/error.c

@@ -424,15 +424,14 @@ mrb_sys_fail(mrb_state *mrb, const char *mesg)
 }
 
 MRB_API mrb_noreturn void
-mrb_no_method_error(mrb_state *mrb, mrb_sym id, mrb_int argc, const mrb_value *argv, char const* fmt, ...)
+mrb_no_method_error(mrb_state *mrb, mrb_sym id, mrb_value args, char const* fmt, ...)
 {
   mrb_value exc;
   va_list ap;
 
   va_start(ap, fmt);
   exc = mrb_funcall(mrb, mrb_obj_value(E_NOMETHOD_ERROR), "new", 3,
-                    mrb_vformat(mrb, fmt, ap), mrb_symbol_value(id),
-                    mrb_ary_new_from_values(mrb, argc, argv));
+                    mrb_vformat(mrb, fmt, ap), mrb_symbol_value(id), args);
   va_end(ap);
   mrb_exc_raise(mrb, exc);
 }

src/vm.c

@@ -723,6 +723,8 @@ argnum_error(mrb_state *mrb, mrb_int num)
 
 #define CALL_MAXARGS 127
 
+void mrb_method_missing(mrb_state *mrb, mrb_sym name, mrb_value self, mrb_value args);
+
 MRB_API mrb_value
 mrb_context_run(mrb_state *mrb, struct RProc *proc, mrb_value self, unsigned int stack_keep)
 {
@@ -1078,8 +1080,15 @@ RETRY_TRY_BLOCK:
 
         m = mrb_method_search_vm(mrb, &c, missing);
         if (!m) {
-          mrb_no_method_error(mrb, mid, n, regs+a+1,
-                              "undefined method '%S' for %S", mrb_sym2str(mrb, mid), recv);
+          mrb_value args;
+
+          if (n == CALL_MAXARGS) {
+            args = regs[a+1];
+          }
+          else {
+            args = mrb_ary_new_from_values(mrb, n, regs+a+1);
+          }
+          mrb_method_missing(mrb, mid, recv, args);
         }
         mid = missing;
         if (n == CALL_MAXARGS) {