[R-sig-dyn-mod] Problem with loading compiled code into R

[Tim Keitt]

On Fri, Apr 7, 2017 at 10:08 PM, Tim Keitt <tkeitt at utexas.edu> wrote:

> If you google that error message, you will find the answer. (clang v. gcc)
>

Let me clarify as I was alerted that that sounded harsh. (Not my intention.)

This error is often reported when linking code C++ compiled with gcc to
code compiled with clang. Those don't work well together. If your R was
compiled with gcc (clang), then you cannot use clang (gcc) to compile code
to link with R (even the g++-alike that comes with llvm).

The trick is to use "R CMD config" to find the compiler used to compile R.

In R (for the C++ compiler):

> Sys.setenv(CXX = system2("R", "CMD config CXX", stdout = TRUE))
> Sys.which(Sys.getenv("CXX"))  # should return compiler path

After that, "R CMD SHLIB --clean" should use the correct compiler and link
properly.

You can also try declaring your call point "extern C" to use the C linkage
ABI.

If you're using C rather than C++, then I'm not sure why it does not work
as the C linkage ABI is supposed to be standardized. You can try the above
with CC in place of CXX. Maybe that will fix it.

THK

http://www.keittlab.org/

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