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Re: [PATCH 2/3] Add a lot of dummy returns to avoid warnings with NO_NORETURN

From
Jonathan Nieder <jrnieder@gmail.com>
Date
Jun 20, 2011, 22:46 UTC
Message-ID
<20110620224619.GB695@elie>
In-Reply-To
<20110620223705.GG32765@one.firstfloor.org>
Andi Kleen wrote:
> To be honest it's still not clear to me what was wrong with patch (2).

Ah, ok. From my point of view the patch was problematic since it adds code that would be distracting to both humans and static analyzers. For example, a person might wonder "why this return value and not another?". Even worse, if someone removes a die() call and introduces a bug, we lose the benefit of the warnings you are suppressing.

Show 7 quoted lines
>> In this case, since the NO_NORETURN knob is to work around a gcc bug,
>> wouldn't it make sense to add a -Wno-something-or-other option to
>> BASIC_CFLAGS or COMPAT_CFLAGS when it is set?
>
> The problem is that only relatively new gccs have options to do
> fine grained control on all warnings. So this would add more complications
> in the Makefile to check the compiler version

The default CFLAGS is very simple because git is supposed to be possible to build with other compilers, too, and I wasn't suggesting changing that. But I suspect making NO_NORETURN assume a modern enough gcc to trigger the bug might be ok.

Anyway, thanks for writing these patches. I'm happy to see git get faster. As a side question, do you know if gcc provides a way to print output about what profile-driven optimizations were especially compelling, so they could help people think about how to reorganize code to improve the non profile-driven builds, too?

Regards, Jonathan

Previous: Andi KleenNext: Jonathan Nieder
Message 9 of 20 in “Add option to disable NORETURN”
  1. 1/3 Add option to disable NORETURNAndi Kleen, Jun 19, 2011
  2. 2/3 Add a lot of dummy returns to avoid warnings with NO_NORETURNAndi Kleen, Jun 19, 2011
  3. Junio C HamanoJun 20, 2011
  4. Andi KleenJun 20, 2011
  5. Junio C HamanoJun 20, 2011
  6. Andi KleenJun 20, 2011
  7. Jonathan NiederJun 20, 2011
  8. Andi KleenJun 20, 2011
  9. Jonathan NiederJun 20, 2011
  10. Jonathan NiederJun 20, 2011
  11. Andi KleenJun 21, 2011
  12. Jonathan NiederJun 21, 2011
  13. Junio C HamanoJun 20, 2011
  14. Andi KleenJun 21, 2011
  15. Junio C HamanoJun 20, 2011
  16. Andi KleenJun 20, 2011
  17. Junio C HamanoJun 20, 2011
  18. Andi KleenJun 20, 2011
  19. Junio C HamanoJun 21, 2011
  20. 3/3 Add profile feedback build to git v2Andi Kleen, Jun 19, 2011

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