Dealing with decorated external binaries when building a package with Rcpp - c++

Question

I am using a Window 32-bit machine to compile an R package developed using Rcpp and compiled with Rtools 3.4 in RStudio 1.0.28. I keep getting an error about the # signs within the 32-bit external dll (NYCgeo.dll):
thefile.o:thefile.cpp:(.text+0x913): undefined reference to `_imp__NYCgeo#8'
collect2.exe: error: ld returned 1 exit status
Sure enough, when I opened the 32-bit NYCgeo.dll in a text editor, I found #8 suffix. This is weird because when I developed the 64-bit version, the 64-bit NYCgeo.dll did not contain #8 suffix and I did not have any errors. Anyway, I read about the --kill-at command and was wondering where I would include it. I tried RStudio's Configure Build Tools settings as well as my makevars.win.in file but had no luck.
Response to #Dirk
Updated title as requested.
I am compiling the package from within RStudio using Rtools so I assumed it might have something to do with RStudio's Project Options.
I have spent the past week checking existing documentation. This post, this post, and this post describe the issue I am having. My issue is that I do not know where to specify either "--kill-at" or "--add-stdcall-alias"
The whole point of my package is to leverage NYC Dept of City Planning's geocoding software. I did not "just throw" the binary NYCgeo.dll "into the mix." In fact, my 64-bit version of the package works fine. My issue is with developing the 32-bit version... specifically, the presence of an #8 suffix in the NYCgeo.dll binary which is causing an error.
NYCgeo.dll is a C binary. I am not using Visual Studio.
The previous question you mentioned dealt with creating Makevars files for the 64-bit version of my package (thanks again, #Coatless for providing useful information). The 64-bit NYCgeo.dll binary did not contain an #8 suffix.
UPDATE:
I tried to create a better title for this question. The question pertains to creating an R package which utilizes functionality from another piece of software... in my case, geocoding software. Specifically, the issue I experienced is that the 32-bit version of the geocoding software has a decorated dll files while the 64-bit version does not. A decorated binary contains # symbols which trigger an error during compiling. My task was to devise a way to demangle (not sure if that is a real word) the 32-bit dll but leave the 64-bit dll alone.
Many thanks.
Gretchen

Answer 1

The rJava package was incredibly helpful in understanding how to deal with decorated binaries.
I created a def file named NYCgeo.def and saved it in my src directory:
LIBRARY NYCGEO.DLL
EXPORTS
NYCgeo#8
I then updated my Makevars.win.in file which is also in my src directory:
GBAT_PATH = #GBAT_PATH#
GBAT_DLL = #GBAT_DLL#
PKG_LIBS = -L"$(GBAT_PATH)/Bin" -l$(GBAT_DLL)
PKG_CPPFLAGS = -I"$(GBAT_PATH)/Include"
ifeq "${R_ARCH}" "/i386"
$(SHLIB): $(OBJECTS) NYCGEO.a
NYCGEO.a: NYCGEO.def
$(DLLTOOL) -k -d NYCGEO.def -l NYCGEO.a -D "$(GBAT_PATH)/Bin/$(GBAT_DLL)" $(DT_ARCH)
endif
I am now able to compile the package on both 32-bit and 64-bit machines running Windows.