Re: BUG #7588: pgsql 9.1 incompatible with zlib 1.27

On 10/7/2012 22:26, Tom Lane wrote:
> John Marino<draco@marino.st>  writes:
>> Are you 100% sure that offsetof is evaluated at compile time?  Is this
>> not part of section 6.6 that I quoted earlier?
>
> My copy of C99 sayeth (in section 7.17)
>
>                 offsetof(type, member-designator)
>
>         which expands to an integer  constant  expression  that  has
>         type  size_t,  the value of which is the offset in bytes, to
>         the structure member (designated by member-designator), from
>         the  beginning  of  its structure (designated by type).
>
> If your version of gcc isn't treating it as an integer constant
> expression, you either have a bug in the compiler or a bug in your
> version of<stddef.h>.  And I will say once more that we have not
> encountered any other report of gcc having a problem with this code.
>
>             regards, tom lane

Thanks Tom.
It is possible the culprit is the offsetof expansion.  I'm examining the
FreeBSD version and there's a slight difference from that.  I will
investigate this further and pass on what I find out.  I don't suspect
the compiler though -- I've seen this on multiple compilers in the last
few months, namely a stock gcc 4.6 as well.  It also choked on offsetof.

Regards,
John