GCC version bikeshedding

[pinskia@gmail.com]

> On Aug 6, 2014, at 2:10 AM, Marek Polacek <polacek@redhat.com> wrote:
> 
>> On Wed, Aug 06, 2014 at 11:04:14AM +0200, Richard Biener wrote:
>>> On Wed, Aug 6, 2014 at 10:48 AM, Jakub Jelinek <jakub@redhat.com> wrote:
>>> - libstdc++ ABI changes (it is a significant user visible change,
>>>  if you rebuild everything, no extra effort is needed, but otherwise
>>>  if you want some C++ code built with older compilers work together
>>>  with code built with newer compilers, it might require source code
>>>  changes (the abi_tag attribute additions where needed and warning
>>>  suggest to put those at), at least that is my current understanding
>>>  of the plans
>> 
>> But that's only with -std=c++11?  Which had no compatibility
>> guarantees before?
>> 
>>> - likely libgfortran ABI changes (different array descriptors)
>> 
>> Let's wait and see ...
>> 
>> We'll find a good reason to bump the major with every release.
>> Like for 4.9 LTO defaults to slim-objects, or C++ rejecting even more
>> invalid code, or libstdc++ header re-orgs, or defaulting to dwarf4+
>> (or even support for it), or VTA, or ...
>> 
>> Where do we set the barrier?  GCC isn't a C++ (or Fortran) compiler
>> only.
>> 
>> So if we change to 5.1 (please not .0) then let's switch the default
>> optimization level to -O2!  _That's_ a user-visible change across
>> the board.
> 
> I'm planning to move the default C standard from gnu90 to gnu11
> (Currently it's blocked on the -Wc90-c99-compat warning).
> That's a pretty big user-visible change as well, I suppose.

I don't think this is a good move due to extern inline and a lot of code is still k&r c and not even c90. 

Thanks,
Andrew

> 
>    Marek