RE: Unable to mind .lib files after successfully compiling EPICS using mingw64

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

Hi,

 

The default DLL search order includes the directory of the main executable and PATH, so ca.dll / com.dll in the same directory as  mca.mexw64 may not be enough unless that directory also gets added by matlab automatically. Try moving Com.dll and ca.dll to either a directory in your PATH or the same directory as  matlab.exe

 

Regards,

 

Freddie  

 

From: Tech-talk <tech-talk-bounces at aps.anl.gov> On Behalf Of Wang, Andrew via Tech-talk
Sent: 29 April 2025 03:08
To: Mark Rivers <rivers at cars.uchicago.edu>; EPICS tech-talk <tech-talk at aps.anl.gov>
Subject: RE: Unable to mind .lib files after successfully compiling EPICS using mingw64

 

Hi Mark,

 

Thanks for the clarification. Not sure if you can help me with this, but I was able to get mca compiled using mex on MATLAB with this command (I removed parts of the path for just this email for reasons):

 

mex -R2017b mca.cpp MCAError.cpp Channel.cpp ...

            <TOP>\epics-base\lib\windows-x64-mingw\libCom.dll.a ...

            <TOP>\epics-base\lib\windows-x64-mingw\libca.dll.a ...

           -D_MINGW ...

           -IC:\Users\wang126\epics-base\include ...

           -IC:\Users\wang126\epics-base\include\os\WIN32 ...

           -IC:\Users\wang126\epics-base\include\compiler\gcc ...

           -v

 

On MATLAB 2024b, mex completed successfully. However when I went to run mca.mexw64, it states that:

 

Invalid MEX-file <TOP>\matlab_ca\mca.mexw64': The specified module could not be found.

 

Reading through the MATLAB forums, I used the dependency tool that came with MSVC to find what its dependencies are. They are listed below.

 

Dump of file mca.mexw64

 

File Type: DLL

 

  Image has the following dependencies:

 

    libmex.dll

    libmx.dll

    KERNEL32.dll

    msvcrt.dll

    ca.dll

    Com.dll

 

I have ca.dll and Com.dll in the same directory as mca.mexw64. The others are found in PATH. I feel like I am missing something important, but not sure what it is.

From: Mark Rivers <rivers at cars.uchicago.edu>
Sent: Monday, April 28, 2025 6:18 PM
To: EPICS tech-talk <tech-talk at aps.anl.gov>; Wang, Andrew <wang126 at llnl.gov>
Subject: Re: Unable to mind .lib files after successfully compiling EPICS using mingw64

 

When you build dynamically on Windows with VS there are 2 files:

• .lib contains the symbols

• .dll contains the code

 

When you link, as in the Matlab Makefile, you only link with the .lib files.  It finds the .dll files at run-time.

 

When you build statically on Windows with VS there is only a .lib file, which contains both the symbols and the code.  It does not need to find .dll files at run-time.

 

I am sure pretty sure that Matlab is linking to the dynamic DLLs for ca and Com.

 

Mark

 

 

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From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Wang, Andrew via Tech-talk <tech-talk at aps.anl.gov>
Sent: Monday, April 28, 2025 8:01 PM
To: EPICS tech-talk <tech-talk at aps.anl.gov>
Subject: Unable to mind .lib files after successfully compiling EPICS using mingw64

 

Hi all,

 

I have been tasked with building EPICS on Windows. I was able to get it compiling using mingw64. I basically followed the instructions here (https://docs.epics-controls.org/en/latest/getting-started/installation-windows-msys2.html), albeit I did not use the tar.gz file. I instead cloned the epics-base repository.

 

I have been able to run an IOC and all of that. However, now I am trying to get mca to work, which requires com.lib and ca.lib. However, I do not see these in my lib directory. I only find com.dll.a and ca.dll.a, which to my understanding is not a static library.

 

The examples compilations in mca all use .lib. (https://github.com/epics-extensions/matlab_ca/blob/master/alt_compile/mcacompile_win64_mscc.m)

 

Please advise?

 

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