R devel - Nov 2007 - problem in linking to libR.so with R 2.5.0

Dear All,

I tried to write a C++ program that uses R internals and I encounter
"undefined reference" error when linking to libR.so. Here is an small
example of the program test.cpp:

extern "C" {
#include <config.h>
#include <IOStuff.h>

int main(int argc, char** argv)
{
  R_IoBufferInit(&R_ConsoleIob);
  return 0;
}
}

I built it using:
g++ -o test -I/dir/to/R-2.5.0/src/include -L/dir/to/R-2.5.0/lib/R/lib -lR
test.cpp

and I got the error message:

/tmp/cc4zxrqh.o(.text+0x20): In function `main':
test.cpp: undefined reference to `R_ConsoleIob'
/tmp/cc4zxrqh.o(.text+0x25):test.cpp: undefined reference to
`R_IoBufferInit'
collect2: ld returned 1 exit status

I installed R 2.5.0 on Fedora Core 4 with gcc 4.0.2 and configured with
--prefix=/dir/to/R-2.5.0 --enable-R-shlib

I did that with R 2.2.1 and can build without problem. Any suggestion on
how to link to libR.so in later R versions? Your help is very appreciated.

Best regards,
Jiangtian

IOStuff.h is not a public header, and neither are the entry points within 
it.  See 'Writing R Extensions'.  One is in the category:

   Entry points that are where possible (Windows and some modern Unix
   compilers/loaders when using @R{} as a shared library) not exported.


On Wed, 7 Nov 2007, Jiangtian Li wrote:
> Dear All,
>
> I tried to write a C++ program that uses R internals and I encounter
> "undefined reference" error when linking to libR.so. Here is an
small
> example of the program test.cpp:
>
> extern "C" {
> #include <config.h>
> #include <IOStuff.h>
>
> int main(int argc, char** argv)
> {
>  R_IoBufferInit(&R_ConsoleIob);
>  return 0;
> }
> }
>
> I built it using:
> g++ -o test -I/dir/to/R-2.5.0/src/include -L/dir/to/R-2.5.0/lib/R/lib -lR
> test.cpp
You need -I/dir/to/R-2.5.0/include to get the public headers.
> and I got the error message:
>
> /tmp/cc4zxrqh.o(.text+0x20): In function `main':
> test.cpp: undefined reference to `R_ConsoleIob'
> /tmp/cc4zxrqh.o(.text+0x25):test.cpp: undefined reference to
`R_IoBufferInit'
> collect2: ld returned 1 exit status
>
> I installed R 2.5.0 on Fedora Core 4 with gcc 4.0.2 and configured with
> --prefix=/dir/to/R-2.5.0 --enable-R-shlib
>
> I did that with R 2.2.1 and can build without problem. Any suggestion on
> how to link to libR.so in later R versions? Your help is very appreciated.
>
> Best regards,
> Jiangtian
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.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)
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