Experimental Physics and
Industrial Control System

Freddie Akeroyd - UKRI STFC <[email protected]> · Wed, 16 May 2018 22:36:24 +0000

Hi Lewis,

We are using ffmpegServer on windows, I had to make a few changes to get it all to work which I apologise for not feeding back to the community yet.  Our code is in https://github.com/ISISComputingGroup/EPICS-areaDetector if that helps. If I recall correctly you do not need to build nullhttp as a separate module, the source files are included directly by the Makefile for ffmpegServer. 

Regards,

Freddie   

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of J. Lewis Muir
Sent: 16 May 2018 23:22
To: EPICS Tech-Talk
Subject: Re: Error LNK2005 building Diamond's nullhttpd module on Windows

On 05/16, J. Lewis Muir wrote:
> It was noted in a private email that the <nullhttpd>/src/nullhttpd.h 
> header contains the following lines in a WIN32 ifdef which appear to 
> add a library-search record to the object file and define _MT to 1:
> 
> ===
> #pragma comment(lib, "libcmt.lib")
> #pragma comment(lib, "wsock32.lib")
> #define _MT 1
> ===
> 
> I tried reverting the "/NODEFAULTLIB:LIBCMT.lib" change and commenting 
> out the "libcmt.lib" pragma line and the _MT define line, but still no 
> dice; it's the same error I got after making the 
> "/NODEFAULTLIB:LIBCMT.lib" change (full output at the end of this
> email):
> 
> ===
> link -nologo -subsystem:windows -dll -LTCG -incremental:no -opt:ref -release       -implib:nullhttpd.lib -out:nullhttpd.dll         cgi.obj files.obj http.obj win32.obj config.obj format.obj server.obj main.obj
> server.obj : error LNK2001: unresolved external symbol 
> __imp__MessageBoxA@16 ===

After more web searching, I tried adding the following to the WIN32 ifdef in <nullhttpd>src/nullhttpd.h:

===
#pragma comment(lib, "user32.lib")
===

And now it compiles successfully!

But this is just a bunch of hacking; I don't know enough about Windows to know what's the right thing to do.  I'll report back once I have things narrowed down a bit.

Lewis

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System