Re: Patch: Remove gcc dependency in definition of inline functions

On Wed, Dec 16, 2009 at 9:30 AM, Marko Kreen <markokr(at)gmail(dot)com> wrote:
> On 12/16/09, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> On Tue, Dec 15, 2009 at 10:34 PM, Kurt Harriman <harriman(at)acm(dot)org> wrote:
>>  >> Your worry ii) can be ignored, managing to compile on such
>>  >> compilers is already overachievement.
>>  >
>>  > I think so too.  With your opinion added to mine, do we constitute a
>>  > consensus of the pg community?  Someone might object that a sample of
>>  > two individuals is insufficiently representative of the whole, but
>>  > away with the pedants: let us not quibble over trifles.
>>
>>
>> I haven't completely followed this thread, but I think there has been
>>  some discussion of making changes to inline that would cause
>>  regressions for people using old, crappy compilers, and I think we
>>  should avoid doing that unless there is some compelling benefit.  I'm
>>  not sure what that benefit would be - I don't think "cleaner code" is
>>  enough.
>
> Seems you have not followed the thread...
>
> Hypothetical old, crappy compilers would still work, only AC_C_INLINE
> would turn "static inline" into plain "static", so hypothetically
> they would get some warnings about unused functions.
>
> As this is all hypothetical, I don't see why that should stop us
> cleaning our code?

I don't think that hypothetical is the right word. There is no
question that such compilers exist. What seems to me to be relevant
is whether anyone is still using them. Maybe with sufficient research
you could demonstrate that there are no platforms we support where
these are still in common use - e.g. the oldest version of AIX
compiler that has this problem is version X, but PostgreSQL is only
supported on versions Y and higher, where Y>X. But I don't see that
any attempt has been made to do that research, or at least I haven't
seen any attempt to go through our supported platforms and discuss the
situation for each one.

I'm not really sure there's enough benefit in this project to warrant
that effort, but that's up to you to decide. However, I am pretty
confident that there is going to be opposition to degrading
performance or causing lots of compiler warnings on older platforms
that are still supported. In fact, such opposition has already been
registered on this thread and you can find it here:

http://archives.postgresql.org/pgsql-hackers/2009-12/msg00239.php

Our standard for accepting patches is that (1) they have a
demonstrated benefit and (2) they don't break anything. Leaving aside
the question of whether this patch makes anything worse, it would
really improve the case for this patch if someone could enumerate the
supported platforms and compilers where it makes things better.

...Robert