change mrb_warn to get mrb_state and %S formatter

include/mruby.h

@@ -299,7 +299,7 @@ void mrb_exc_raise(mrb_state *mrb, mrb_value exc);
 void mrb_raise(mrb_state *mrb, struct RClass *c, const char *msg);
 void mrb_raisef(mrb_state *mrb, struct RClass *c, const char *fmt, ...);
 void mrb_name_error(mrb_state *mrb, mrb_sym id, const char *fmt, ...);
-void mrb_warn(const char *fmt, ...);
+void mrb_warn(mrb_state *mrb, const char *fmt, ...);
 void mrb_bug(const char *fmt, ...);
 
 /* macros to get typical exception objects

mrbgems/mruby-sprintf/src/sprintf.c

@@ -1070,7 +1070,7 @@ retry:
   if (posarg >= 0 && nextarg < argc) {
     const char *mesg = "too many arguments for format string";
     if (mrb_test(ruby_debug)) mrb_raise(mrb, E_ARGUMENT_ERROR, mesg);
-    if (mrb_test(ruby_verbose)) mrb_warn("%s", mesg);
+    if (mrb_test(ruby_verbose)) mrb_warn(mrb, "%S", mrb_str_new_cstr(mrb, mesg));
   }
 #endif
   mrb_str_resize(mrb, result, blen);

mrbgems/mruby-struct/src/struct.c

@@ -252,7 +252,7 @@ make_struct(mrb_state *mrb, mrb_value name, mrb_value members, struct RClass * k
       mrb_name_error(mrb, id, "identifier %S needs to be constant", name);
     }
     if (mrb_const_defined_at(mrb, klass, id)) {
-      mrb_warn("redefining constant Struct::%s", mrb_string_value_ptr(mrb, name));
+      mrb_warn(mrb, "redefining constant Struct::%S", name);
       //?rb_mod_remove_const(klass, mrb_sym2name(mrb, id));
     }
     c = mrb_define_class_under(mrb, klass, RSTRING_PTR(name), klass);

src/class.c

@@ -255,13 +255,12 @@ mrb_define_class_under(mrb_state *mrb, struct RClass *outer, const char *name, s
   if (mrb_const_defined_at(mrb, outer, id)) {
     c = class_from_sym(mrb, outer, id);
     if (mrb_class_real(c->super) != super) {
-        mrb_name_error(mrb, id, "%S is already defined", mrb_sym2str(mrb, id));
+      mrb_name_error(mrb, id, "%S is already defined", name);
     }
     return c;
   }
   if (!super) {
-    mrb_warn("no super class for `%S::%S', Object assumed",
-             mrb_obj_value(outer), mrb_sym2str(mrb, id));
+    mrb_warn(mrb, "no super class for `%S::%S', Object assumed", outer, name);
   }
   c = mrb_class_new(mrb, super);
   setup_class(mrb, mrb_obj_value(outer), c, id);

src/error.c

@@ -312,15 +312,17 @@ mrb_name_error(mrb_state *mrb, mrb_sym id, const char *fmt, ...)
 }
 
 void
-mrb_warn(const char *fmt, ...)
+mrb_warn(mrb_state *mrb, const char *fmt, ...)
 {
 #ifdef ENABLE_STDIO
-  va_list args;
+  va_list ap;
+  mrb_value str;
 
-  va_start(args, fmt);
-  printf("warning: ");
-  vprintf(fmt, args);
-  va_end(args);
+  va_start(ap, fmt);
+  str = mrb_vformat(mrb, fmt, ap);
+  fputs("warning: ", stderr);
+  fwrite(RSTRING_PTR(str), RSTRING_LEN(str), 1, stderr);
+  va_end(ap);
 #endif
 }