Re: [PATCH][Middle-end][Version 4]Add a new option to control inlining only on static functions

[Qing Zhao <qing.zhao@oracle.com>]

Alexander,

thanks for the questions.

Yes, we had some discussion on the questions you raised during the review of the initial patch back to 9/11/2018.
please take a look at those discussions at:

https://gcc.gnu.org/ml/gcc-patches/2018-09/msg00549.html <https://gcc.gnu.org/ml/gcc-patches/2018-09/msg00549.html>
https://gcc.gnu.org/ml/gcc-patches/2018-09/msg00787.html <https://gcc.gnu.org/ml/gcc-patches/2018-09/msg00787.html>

and let me know if those discussion still does not answer your questions.

Qing

> On Sep 26, 2018, at 6:12 AM, Alexander Monakov <amonakov@ispras.ru> wrote:
> 
> On Fri, 21 Sep 2018, Qing Zhao wrote:
>> +2018-09-20  Qing Zhao  <qing.zhao@oracle.com>
>> +
>> +	* cif-code.def (FUNCTION_EXTERN): New CIFCODE.
>> +	* common.opt (-finline-only-static): New option.
>> +	* doc/invoke.texi: Document -finline-only-static.
>> +	* ipa-inline.c (can_inline_edge_p): Control inlining based on
>> +	function's linkage. 
> 
> Note, I am not a reviewer.
> 
> In my opinion, there's a problem with the patch that it looks like an ad-hoc,
> incomplete solution. You said you need this change to help with building
> livepatching-capable kernels, but it's not clear what exactly the issue with
> inlining non-static functions is. Can you describe how the workflow looks like
> so code duplication due to inlining static functions is not an issue, but
> inlining non-static functions is a problem? Does using existing
> -fno-inline-functions flag achieve something useful for your usecase?
> 
> Please always make it clear what problem the patch is intended to solve and help
> reviewers see the connection between the problem and your solution. Look how the
> "XY problem" effect applies partially in this situation.
> 
> https://en.wikipedia.org/wiki/XY_problem
> http://xyproblem.info/
> 
> Alexander