Re: Cygwin linking rules

On 09/29/2018 01:03 PM, Andrew Dunstan wrote:
>
>
> On 09/29/2018 12:09 PM, Andrew Dunstan wrote:
>>
>>
>> On 09/29/2018 11:35 AM, Tom Lane wrote:
>>> Most of the buildfarm is now happy with the changes I made to have
>>> libpq + ecpg get src/port and src/common files via libraries ...
>>> but lorikeet isn't.  It gets through the core regression tests fine
>>> (so libpq, per se, works), but contrib/dblink fails:
>>>
>>> ! ERROR:  could not establish connection
>>> ! DETAIL:  libpq is incorrectly linked to backend functions
>>>
>>> What this means is that libpq is calling the backend version of
>>> src/common/link-canary.c rather than the frontend version.
>>> Why would it do the right thing normally and the wrong thing in dblink?
>>>
>>> I can think of a few theories but I lack the ability to investigate:
>>>
>>> 1. Maybe the dblink.dll build is pulling in libpq.a rather than
>>> establishing a reference to libpq.dll.  If so, the wrong things would
>>> happen because libpq.a won't contain the src/common/ files that
>>> libpq needs.  (It seems like libpq.a is an active hazard given
>>> this.  Why are we building it at all?)
>>>
>>> 2. Maybe we need a --version-script option or something equivalent
>>> to get libpq.dll's references to be preferentially resolved internally
>>> rather than to the backend.  But this doesn't really explain why it
>>> worked properly before.
>>>
>>>
>>
>>
>>
>> I will see if I can determine if 1) is the cause. I don't know
>> enough, or in fact anything, about 2), so don;t know that I can help
>> there without advice.
>>
>>
>
>
>
> It certainly looks like it's not linked to libpq.dll:
>
>    Microsoft (R) COFF/PE Dumper Version 14.15.26726.0
>    Copyright (C) Microsoft Corporation.  All rights reserved.
>
>
>    Dump of file
> \cygwin64\home\andrew\\bf64\root\HEAD\inst\lib\postgresql\dblink.dll
>
>    File Type: DLL
>
>       Image has the following dependencies:
>
>         postgres.exe
>         cygcrypto-1.0.0.dll
>         cygwin1.dll
>         cygssl-1.0.0.dll
>         KERNEL32.dll
>
>
> I'll build an earlier version to do a comparison just to make sure
> we're seeing the right thing.
>
>
>

Hmm. Getting the same result from REL_10_STABLE.

Not sure where to go from here.

cheers

andrew

--
Andrew Dunstan https://www.2ndQuadrant.com
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