[R-pkg-devel] [Learning] the secret of Win[dows C-backed packages]

[Dirk Eddelbuettel]

I don't think there is a good "generally applicable" solution.  We have a
bunch of hacks. Below are three quickly picked examples from packages of mine:

RQuantLib relies on environment variables and a 'library that needs to just
be there' on the build host:

   ## The environment variable QUANTLIB_ROOT has to point to an existing build of QuantLib
   ## With R 2.12.0 and later, we also support 32 and 64 bit builds and need to differentiate
   PKG_CPPFLAGS=-I$(QUANTLIB_ROOT) -I../inst/include -I. -I$(BOOSTLIB) 
   PKG_CXXFLAGS=$(SHLIB_OPENMP_CFLAGS) -fpermissive 
   PKG_LIBS=-L$(QUANTLIB_ROOT)/lib${R_ARCH} -lQuantLib $(SHLIB_OPENMP_CFLAGS) 

RcppGSL does the same

   ## This assumes that the LIB_GSL variable points to working GSL libraries
   PKG_CPPFLAGS=-I$(LIB_GSL)/include -I../inst/include
   PKG_LIBS=-L$(LIB_GSL)/lib -lgsl -lgslcblas 

Rblpapi copies a library (for which we have 'free' binaries but no source) in
from GitHub:

   ## target to ensure tar.gz files get unpacked
   ## the opening '@' ensures operations are executed 'quietly'
   ## in order to see commands as they happens add a 'v' to the tar and cp commands
   ## curl has '-k' flag to suppress certificate warnings
   blpLibrary:
   		@if [ ! -d ../inst ]; then mkdir -p ../inst; fi
		@if [ ! -d ../blp/win/${FLV} ]; then mkdir -p ../blp/win/${FLV}; fi
		@if [ ! -f ../blp/win/${FLV}/blpHeaders.tar.gz ]; then curl -s -k -L -O https://github.com/Rblp/blp/raw/master/headers/windows/blpHeaders.tar.gz; mv blpHeaders.tar.gz ../blp/win/${FLV}; tar xfz ../blp/win/${FLV}/blpHeaders.tar.gz -C ../inst; fi
		@if [ ! -f ../blp/win/${FLV}/blpLibrary.tar.gz ]; then curl -s -k -L -O https://github.com/Rblp/blp/raw/master/win${WIN}/blpLibrary.tar.gz; mv blpLibrary.tar.gz ../blp/win/${FLV}; tar xfz ../blp/win/${FLV}/blpLibrary.tar.gz; fi
		@if [ ! -d ${FLV} ]; then mkdir -p ${FLV}; fi
		@cp blpapi3_${WIN}.dll ${FLV}
		@if [ ! -d ../inst/libs/${FLV} ]; then mkdir -p ../inst/libs/${FLV}; fi
		@cp blpapi3_${WIN}.dll ../inst/libs/${FLV}


None of that really generalizes well.  The last bit, much like the so-called
anticonf pattern, is more or less a non-standard practice exposing a security
risk by copying in code from a semi-random location which could be hijacked
or man-in-the-middle'd.

Really all this is just pretending that Windows is an envrionment on which
you can deploy proper build systems -- similar to what we are used from the
likes of dpkg/apt/yum or brew.  But in all honesty you just can't.

So I would not try to aim for something overly general.  It is Windows after all.

Dirk

-- 
http://dirk.eddelbuettel.com | @eddelbuettel | edd at debian.org