# Are any compiler flags set on the online judge? **URL:** \ **Category:** faq\ **Tags:** compiler, faq\ **Created:** [April 10, 2013, 3:55pm UTC](https://discuss.codechef.com/t/are-any-compiler-flags-set-on-the-online-judge/1866 "2013-04-10T15:55:52Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![anup](https://discuss.codechef.com/user_avatar/discuss.codechef.com/anup/32/257725_2.png) [@anup](https://discuss.codechef.com/u/anup)\ **Post date:** [April 10, 2013, 3:55pm UTC](https://discuss.codechef.com/t/are-any-compiler-flags-set-on-the-online-judge/1866/1 "2013-04-10T15:55:52Z")
Does the online judge have any compiler flags set? ---
**Author:** ![admin](https://discuss.codechef.com/user_avatar/discuss.codechef.com/admin/32/212587_2.png) [@admin](https://discuss.codechef.com/u/admin)\ **Post date:** [April 10, 2013, 3:56pm UTC](https://discuss.codechef.com/t/are-any-compiler-flags-set-on-the-online-judge/1866/2 "2013-04-10T15:56:29Z")
This is the updated information regarding flags on the compilers set by online judge as of March 2024. - **C++ :** ```auto O2 - second optimization level, lm - access to "math.h" library, fomit-frame-pointer - disallow to store frame pointer in CPU register, pthread - enable multithreading ``` - **C :** ```auto O2 - second optimization level, lm - access to "math.h" library, fomit-frame-pointer - disallow to store frame pointer in CPU register, pthread - enable multithreading ``` - **Rust :** ```auto opt-level=2 - second optimization level edition=2024 ``` ### Runtime Flags - **Java :** ```auto Xss64m ``` - \*\* PyPy 3 :\*\* ```auto OO ``` ---
**Author:** ![betlista](https://discuss.codechef.com/user_avatar/discuss.codechef.com/betlista/32/203_2.png) [@betlista](https://discuss.codechef.com/u/betlista)\ **Post date:** [April 10, 2013, 4:00pm UTC](https://discuss.codechef.com/t/are-any-compiler-flags-set-on-the-online-judge/1866/3 "2013-04-10T16:00:30Z")
Here is more complete answer - [What are the compiler options that the judge uses? - faq - CodeChef Discuss](http://discuss.codechef.com/questions/3480/what-are-the-compiler-options-that-the-judge-uses) Previous part is from FAQ - [FAQ | CodeChef](http://www.codechef.com/wiki/faq#Are_any_compiler_flags_set_on_the_online_judge) ---
**Author:** ![xyzzy529](https://www.codechef.com/sites/all/themes/abessive/images/user_default_thumb.jpg) [@xyzzy529](https://discuss.codechef.com/u/xyzzy529)\ **Post date:** [January 5, 2015, 8:59am UTC](https://discuss.codechef.com/t/are-any-compiler-flags-set-on-the-online-judge/1866/4 "2015-01-05T08:59:32Z")
Is ONLINE\_JUDGE actually set properly? Please look at [this question](http://discuss.codechef.com/questions/60767/defined-online_judge-for-testing-and-real-judge-runs) for an example. Thanks. ---
**Author:** ![betlista](https://discuss.codechef.com/user_avatar/discuss.codechef.com/betlista/32/203_2.png) [@betlista](https://discuss.codechef.com/u/betlista)\ **Post date:** [January 5, 2015, 4:07pm UTC](https://discuss.codechef.com/t/are-any-compiler-flags-set-on-the-online-judge/1866/5 "2015-01-05T16:07:49Z")
You can check yourself, for example by throwing exception if not set 😉 If there is flag missing, please write an e-mail to [bugs@codechef.com](mailto:bugs@codechef.com) ---
**Author:** ![xyzzy529](https://www.codechef.com/sites/all/themes/abessive/images/user_default_thumb.jpg) [@xyzzy529](https://discuss.codechef.com/u/xyzzy529)\ **Post date:** [January 5, 2015, 11:47pm UTC](https://discuss.codechef.com/t/are-any-compiler-flags-set-on-the-online-judge/1866/6 "2015-01-05T23:47:04Z")
I did check and it is ALSO being set for the IDE (which is not what we want). Sent email to bugs. Thanks. ---
**Author:** ![abcdexter24](https://discuss.codechef.com/user_avatar/discuss.codechef.com/abcdexter24/32/7452_2.png) [@abcdexter24](https://discuss.codechef.com/u/abcdexter24)\ **Post date:** [June 25, 2016, 11:23am UTC](https://discuss.codechef.com/t/are-any-compiler-flags-set-on-the-online-judge/1866/7 "2016-06-25T11:23:50Z")
Also, we can use `#ifdef` instead, right ? ---
**Author:** ![andersk](https://discuss.codechef.com/user_avatar/discuss.codechef.com/andersk/32/12030_2.png) [@andersk](https://discuss.codechef.com/u/andersk)\ **Post date:** [May 14, 2019, 1:59am UTC](https://discuss.codechef.com/t/are-any-compiler-flags-set-on-the-online-judge/1866/8 "2019-05-14T01:59:26Z")
Rust code is not being compiled with `-O` as claimed, and this is slowing down Rust submissions dramatically, making Rust unusable for many problems. ☹ See [Bug report: Rust code is being compiled in debug mode without optimization](https://discuss.codechef.com/t/bug-report-rust-code-is-being-compiled-in-debug-mode-without-optimization/24530) for reproducible proof. ~~I’ve gotten no response yet from my report to bugs@.~~ (Edit: Actually I got a reasonably quick “we’ll look into this” response that landed in my spam folder, but that’s all so far.)