[Rcpp-devel] Compilation without libR.so ?

[Martin Jakt]

Dear Rcpp developers,

I'm rather new to Rcpp but am very excited by it's abilities; especially with 
the lower degree of effort required to combine R and C++. Thanks!

However, I'm still left a bit mystified by how the source is compiled and 
packages built. I have tried to read the guidelines for extending R, but it is 
rather long and it seems to assume knowledge of many things I don't really 
understand.

My situation is this. I've written some C++ code for reading bigWig files (a 
binary genomic data file type) and used Rcpp to provide an R interface to 
this. I can build the package using:

R CMD check / build / INSTALL

and that works. However, I would prefer to be able to compile and link the C++ 
part of this using just make and a suitable Makefile. This almost works, but 
the linker complains about missing references (from libRcpp). This is not very 
surprising as I'd expect that these should be present in libR.so. And I can't 
find libR.so anywhere on the system I'm using. (I don't think it is present, 
and I don't have root access, so..).

Which implies that R CMD is somehow able to link to libR without libR.so?
Is that possible, and if so, how is that achieved?

I suspect the answer is quite simple, but it's not one that I've been able to 
find by googling.

I also have one other question regarding documentation. Is there a reference 
for the set of C++ classes and their interfaces that are defined by libRcpp 
somewhere? I did try to work something out by looking at the Rcpp header 
files, but that's not that straightforward. 

It also doesn't tell me very much about the implementation details. So far I'm 
mostly using information from examples here and there, and making guesses as 
to behaviour. Not really an ideal situation. For example, looking at the 
GenericVector class, I was surprised to find push_front suggesting that it 
doesn't quite mimic the STL vector class, which I believe guarantees that the 
memory is allocated in a contiguous block (possible to combine with push_front 
and push_back, but with some difficulty).

(It looks like 'the book', may have something like this, and I'm planning to 
buy a copy over the weekend, but..).

in any case I'd like to say thanks for the tools; I'm looking forward to 
having a better understanding of them (perhaps even using R in C++, it seems 
somehow so unholy..).

cheers,

Martin