Re: narwhal and PGDLLIMPORT

On 02/10/2014 01:59 PM, Amit Kapila wrote:
> On Mon, Feb 10, 2014 at 8:51 AM, Craig Ringer <craig@2ndquadrant.com> wrote:
>> On 02/05/2014 01:52 PM, Tom Lane wrote:
>>> Craig Ringer <craig@2ndquadrant.com> writes:
>>>> On 02/05/2014 06:29 AM, Tom Lane wrote:
>>>>> I had been okay with the manual PGDLLIMPORT-sprinkling approach
>>>>> (not happy with it, of course, but prepared to tolerate it) as long
>>>>> as I believed the buildfarm would reliably tell us of the need for
>>>>> it.  That assumption has now been conclusively disproven, though.
>>>
>>>> I'm kind of horrified that the dynamic linker doesn't throw its toys
>>>> when it sees this.
>>>
>>> Indeed :-(.
>>>
>>> The truly strange part of this is that it seems that the one Windows
>>> buildfarm member that's telling the truth (or most nearly so, anyway)
>>> is narwhal, which appears to have the oldest and cruftiest toolchain
>>> of the lot.  I'd really like to come out the other end of this
>>> investigation with a clear understanding of why the newer toolchains
>>> are failing to report a link problem, and yet not building working
>>> executables.
>>
>> For MSVC, here's a patch that makes gendef.pl emit DATA annotations for
>> global var exports.
> 
> Is this change intended to avoid the usage of __declspec (dllimport) for
> global variables?
> 
> Won't it increase the build time for Windows as it seems to me you
> are traversing each symbol file to find the global vars?

gendefs.pl does that anyway. This change just annotates emitted entries
with "DATA" if they're exported vars.

It takes a couple of seconds to run gendefs.pl, so I don't think it's
really a big concern.

-- Craig Ringer                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services