Simplify `print_backtrace()`

src/backtrace.c

@@ -25,8 +25,7 @@ typedef void (*each_backtrace_func)(mrb_state*, const struct backtrace_location*
 
 static const mrb_data_type bt_type = { "Backtrace", mrb_free };
 
-mrb_value mrb_exc_to_s(mrb_state *mrb, mrb_value exc);
-mrb_value mrb_mod_to_s(mrb_state *mrb, mrb_value klass);
+mrb_value mrb_exc_inspect(mrb_state *mrb, mrb_value exc);
 mrb_value mrb_unpack_backtrace(mrb_state *mrb, mrb_value backtrace);
 
 static void
@@ -82,7 +81,7 @@ print_backtrace(mrb_state *mrb, struct RObject *exc, mrb_value backtrace)
 {
   int i;
   mrb_int n = RARRAY_LEN(backtrace);
-  mrb_value *loc, mesg, cname;
+  mrb_value *loc, mesg;
   FILE *stream = stderr;
 
   if (n != 0) {
@@ -93,21 +92,12 @@ print_backtrace(mrb_state *mrb, struct RObject *exc, mrb_value backtrace)
                 i, (int)RSTRING_LEN(*loc), RSTRING_PTR(*loc));
       }
     }
-  }
-
-  if (n != 0) {
+    if (mrb_string_p(*loc)) {
       fprintf(stream, "%.*s: ", (int)RSTRING_LEN(*loc), RSTRING_PTR(*loc));
     }
-  mesg = mrb_exc_to_s(mrb, mrb_obj_value(exc));
-  cname = mrb_mod_to_s(mrb, mrb_obj_value(exc->c));
-  if (RSTRING_LEN(mesg) == 0) {
-    fprintf(stream, "%.*s \n", (int)RSTRING_LEN(cname), RSTRING_PTR(cname));
-  }
-  else {
-    fprintf(stream, "%.*s (%.*s)\n",
-            (int)RSTRING_LEN(mesg), RSTRING_PTR(mesg),
-            (int)RSTRING_LEN(cname), RSTRING_PTR(cname));
   }
+  mesg = mrb_exc_inspect(mrb, mrb_obj_value(exc));
+  fprintf(stream, "%.*s\n", (int)RSTRING_LEN(mesg), RSTRING_PTR(mesg));
 }
 
 /* mrb_print_backtrace

src/error.c

@@ -88,7 +88,7 @@ exc_exception(mrb_state *mrb, mrb_value self)
  */
 
 mrb_value
-mrb_exc_to_s(mrb_state *mrb, mrb_value exc)
+exc_to_s(mrb_state *mrb, mrb_value exc)
 {
   mrb_value mesg = mrb_attr_get(mrb, exc, mrb_intern_lit(mrb, "mesg"));
   struct RObject *p;
@@ -127,8 +127,8 @@ exc_message(mrb_state *mrb, mrb_value exc)
  * returns message and class name.
  */
 
-static mrb_value
-exc_inspect(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 cname = mrb_mod_to_s(mrb, mrb_obj_value(mrb_obj_class(mrb, exc)));
@@ -543,9 +543,9 @@ mrb_init_exception(mrb_state *mrb)
   mrb_define_class_method(mrb, exception, "exception", mrb_instance_new,  MRB_ARGS_OPT(1));
   mrb_define_method(mrb, exception, "exception",       exc_exception,     MRB_ARGS_OPT(1));
   mrb_define_method(mrb, exception, "initialize",      exc_initialize,    MRB_ARGS_OPT(1));
-  mrb_define_method(mrb, exception, "to_s",            mrb_exc_to_s,      MRB_ARGS_NONE());
+  mrb_define_method(mrb, exception, "to_s",            exc_to_s,          MRB_ARGS_NONE());
   mrb_define_method(mrb, exception, "message",         exc_message,       MRB_ARGS_NONE());
-  mrb_define_method(mrb, exception, "inspect",         exc_inspect,       MRB_ARGS_NONE());
+  mrb_define_method(mrb, exception, "inspect",         mrb_exc_inspect,   MRB_ARGS_NONE());
   mrb_define_method(mrb, exception, "backtrace",       mrb_exc_backtrace, MRB_ARGS_NONE());
   mrb_define_method(mrb, exception, "set_backtrace",   exc_set_backtrace, MRB_ARGS_REQ(1));