RE: Warning when building ADLightField for windows-x64 with VS2022

[Freddie Akeroyd - STFC UKRI via Tech-talk <tech-talk at aps.anl.gov>]

Hi Mark,

 

I see LightField is compiled with /clr and I think this may be leading to the warning. An  

epicsThreadId is defined as a pointer to a “struct epicsThreadOSD”

https://github.com/epics-base/epics-base/blob/60fa2d31da2deaaa89636b4a1f5b852efe0b2699/modules/libcom/src/osi/epicsThread.h#L108

and this is returned by  epicsThreadCreate() which is used in the lightfield code. The epicsThreadOSD structure is not defined in a public header on windows, which doesn’t normally matter as the native pointer is not meant to be dereferenced in public code, but as per https://learn.microsoft.com/en-us/cpp/error-messages/tool-errors/linker-tools-warning-lnk4248?view=msvc-170 I think the linker is unsure whether it could be a CLR type or a native type hence the warning message you see. If you changed the typedef in epicsThread.h to be:

 

    typedef void *epicsThreadId;

 

I think that may remove the warning as it has broken the link to the undefined epicsThreadOSD type

 

Regards,

 

Freddie

 

From: Tech-talk <tech-talk-bounces at aps.anl.gov> On Behalf Of Mark Rivers via Tech-talk
Sent: 30 September 2023 22:05
To: tech-talk at aps.anl.gov
Subject: Re: Warning when building ADLightField for windows-x64 with VS2022

 

• LightField.obj : warning LNK4248: unresolved typeref token (01000038) for 'epicsThreadOSD'; image may not run
• Does anyone know what causes this warning, and if it is serious?

It does not appear to be serious, because the application seems to run fine.  But I am still interested to know what might be causing that warning.

 

Thanks,

Mark

 

 

---

From: Mark Rivers
Sent: Wednesday, September 27, 2023 12:37 PM
To: tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
Subject: Warning when building ADLightField for windows-x64 with VS2022

 

Folks,

 

I am getting a warning for an unresolved typeref in epicsThreadOSD when building ADLightField for windows-x64 with Visual Studio 2022 Community Edition.

 

link -nologo -subsystem:windows -dll -LTCG -incremental:no -opt:ref -release  -MACHINE:X64      -out:LightField.dll -implib:LightField.lib     LightField.obj        J:/epics/support/areaDetector-3-12-1/ADCore/lib/windows-x64/ADBase.lib  J:/epics/support/asyn-4-44-2/lib/windows-x64/asyn.lib  J:/epics/support/areaDetector-3-12-1/ADCore/lib/windows-x64/ntndArrayConverter.lib  H:/epics/base-7.0.7/lib/windows-x64/nt.lib  H:/epics/base-7.0.7/lib/windows-x64/pvDatabase.lib  H:/epics/base-7.0.7/lib/windows-x64/pvAccess.lib  H:/epics/base-7.0.7/lib/windows-x64/pvData.lib  J:/epics/support/areaDetector-3-12-1/ADSupport/lib/windows-x64/netCDF.lib  J:/epics/support/areaDetector-3-12-1/ADSupport/lib/windows-x64/tiff.lib  J:/epics/support/areaDetector-3-12-1/ADSupport/lib/windows-x64/xml2.lib  J:/epics/support/areaDetector-3-12-1/ADSupport/lib/windows-x64/NeXus.lib  J:/epics/support/areaDetector-3-12-1/ADSupport/lib/windows-x64/hdf5.lib  J:/epics/support/areaDetector-3-12-1/ADSupport/lib/windows-x64/hdf5_hl.lib  J:/epics/support/areaDetector-3-12-1/ADSupport/lib/windows-x64/bitshuffle.lib  J:/epics/support/areaDetector-3-12-1/ADSupport/lib/windows-x64/blosc.lib  J:/epics/support/areaDetector-3-12-1/ADSupport/lib/windows-x64/szip.lib  J:/epics/support/areaDetector-3-12-1/ADSupport/lib/windows-x64/zlib.lib  J:/epics/support/areaDetector-3-12-1/ADSupport/lib/windows-x64/jpeg.lib  H:/epics/base-7.0.7/lib/windows-x64/dbRecStd.lib  H:/epics/base-7.0.7/lib/windows-x64/dbCore.lib  H:/epics/base-7.0.7/lib/windows-x64/ca.lib  H:/epics/base-7.0.7/lib/windows-x64/Com.lib gdi32.lib oleaut32.lib

   Creating library LightField.lib and object LightField.exp

LightField.obj : warning LNK4248: unresolved typeref token (01000038) for 'epicsThreadOSD'; image may not run

 

Does anyone know what causes this warning, and if it is serious?

 

Thanks,

Mark