[EXTERNAL] Re: GCC selftest improvements

[Nicholas Krause]

On 2/12/20 8:53 PM, David Malcolm wrote:
> On Thu, 2020-02-13 at 00:49 +0000, Modi Mo wrote:
>> Hey all,
>>
>> I'm picking this work up from Andrew. Last time it was decided that
>> the timing wasn't right to upgrade the minimum version to C++11. Is
>> the timing better now to get this change through?
>>
>> I've attached the patch Andrew prepared. Can I get feedback on the
>> change and some help testing on the broader range of
>> architectures/platforms?
>>
>> Thanks,
>> Modi
> Hi Modi
>
> Thanks for the patch.
>
> Some nitpicks:
>
> Timing-wise, the GCC developer community is focusing on gcc 10
> bugfixing right now (aka "stage 4" of the release cycle).  So this
> patch won't be suitable to commit to master until stage 1 of the
> release cycle for gcc 11 (in April, hopefully).
>
> But yes, it's probably a good idea to get feedback on the patch given
> the breadth of platforms we support.
>
> The patch will need an update to the docs; search for
> "Tools/packages necessary for building GCC" in gcc/doc/install.texi,
> which currently has some paragraphs labelled:
>    @item ISO C++98 compiler
> that will need changing.
>
> I think Richi mentioned that the minimum gcc version should be 4.8.2 as
> he recalled issues with .1, so maybe the error message and docs should
> reflect that?
>    https://gcc.gnu.org/ml/gcc/2019-10/msg00180.html
>
>
> This may be opening a can of worms that should wait until we're done
> with the GCC 10 release, but there's probably an eventual wider
> discussion about what parts of C++11 we should use; pragmatically we're
> also limited by gengtype, the tool that scrapes the source code looking
> for garbage-collector markup, as that imposes a subset of C++ on us.
>
> I'd love to be able to rely on move semantics and thus use e.g.
> std::unique_ptr to capture more of our memory-management in the type
> system (we currently have a limited C++98-compatible implementation in
> the tree in the form of gnu::unique_ptr).
>
> How much of the stdlib do we see ourselves using?  I think we've
> avoided std::string and the <<-style stream APIs; is there a case for
> using some of the other data structures?
>
> For reference, see
>    https://gcc.gnu.org/codingconventions.html#Cxx_Conventions
> (looks like that page would need an update also for the version bump;
> it's in the website git repo IIRC)
>
> Hope this is constructive.
> Dave
Dave,

I recall originally bringing up the move. From memory I recall that 
these were the
features we wanted or the people in the discussion wanted from C++11:
1. Better Rounding and Stricter Integer and other number type rules
2. Template Aliasing
3. Auto and for each style loops
4. Move and R Value Semantics

There was a little discussion about lambas and anonymous functions but I 
don't
recall that being clear in terms of one of the above areas for sure.

Maybe that helps,
Nick