[Rd] linking to R.dll on Win32 - issues with recent MinGW?

[Prof Brian Ripley]

I was told that direct linking against foo.dll is not supported. One
problem is that the link priority order gets broken, and R.dll gets used
for things it should not be used for (malloc springs to mind).

You should be able to use libR.a, though.  It does not need to export 
R_Home, as you should know what that is when you call R_SetParams.
I would make sure that you are really using the mallocs you think you are.
(One day soon we will try to find a better solution for that, but that 
probably depends on me having a working Windows laptop again, as well as 
time to program on it.)

In a few places (Rlapack.dll as I recall) we have had to force in entry 
points to get things resolved in the right place: pedump will tell you 
where they are resolved, and at least this is done at link time and not 
run time so is fairly easy to track down.

Brian

On Thu, 23 Oct 2003, Simon Urbanek wrote:

> I encountered several strange issues when linking to R.dll on Windows 
> and I wonder if anyone of the Windows savvy-folks here had seen some of 
> the issues before and have some explanation.
> 
> My Rserve links to R dynamic library. That works perfectly on unix 
> boxes and worked fairly well with older MinGW and older R (<=1.7.1). 
> What I do in fact is that I specify
> -L$(R_HOME)/bin -lR
> when linking. This produced valid exe which was linked to R.dll. In 
> fact you could compile everything with the regular binary distribution 
> of R, even without R sources (MinGW got all it needs directly from 
> R.dll).
> 
> Now with R-1.8.0 (which is presumably compiled with more recent MinGW) 
> and MinGW 3.1 this doesn't work anymore on certain Win32 platforms, 
> e.g. I got reports that on W2k Rserve bails out with "Can't load 
> R.dll". Further investigation reveals that the .exe tries to load "R" 
> file and not "R.dll". But if you copy R.dll to R then both R and R.dll 
> get loaded, since R loads Rblas.dll which loads (correctly) R.dll. Then 
> everything crashes (presumably the two dlls fight each other). XP seems 
> to have a fix for that (i.e. a request for "R" will in fact load 
> "R.dll"), but not W2k.
> 
> Did anyone see this or does anyone have an idea how to prevent this 
> (except for downgrading MinGW)?
> 
> Now, I thought I'll use libR.a from the R sources instead of using the 
> final R.dll, because that's what libR.a is for, right? The first 
> obstacle was that libR.a doesn't export R_Home which I need to set in 
> my init routine, but fortunately there is "exported-vars" for that 
> case. But after finally compiling everything, Rserve crashes. It 
> doesn't even get as far as main. What I get is this:
> Warning: Invalid Address specified to RtlSizeHeap( 003F0000, 0146008 )
> and later a crash somewhere deep in libwsock32 (the trace is rather 
> weird) ... I guess the problem is the heap, not wsock itself. Any idea 
> what that could be?
> 
> All the above was tested with MinGW-3.1.
> Any ideas? Is that a MinGW bug or something I did? ;)
> 
> Thanks.
> Simon
> 
> ---
> Simon Urbanek
> Department of computer oriented statistics and data analysis
> University of Augsburg
> Universitätsstr. 14
> 86135 Augsburg
> Germany
> 
> Tel: +49-821-598-2236
> Fax: +49-821-598-2200
> 
> Simon.Urbanek at Math.Uni-Augsburg.de
> http://simon.urbanek.info
> 
> ______________________________________________
> R-devel at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-devel
> 
> 

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595