[Rcpp-devel] fatal error: 'omp.h' file not found

Greetings and Salutations,



OS X does not currently support OpenMP under the default compiler (clang).
Hence, you are receiving an error as it relates to the header file not
being found. For more details, see:



https://cran.r-project.org/doc/manuals/r-release/R-exts.html#OpenMP-support



Support for OpenMP with clang should be arriving sometime in June after
WWDC as the intel funded clang-OpenMP feature has been merged into the main
clang branch. ( http://openmp.llvm.org/ , https://clang-omp.github.io/ )

If this is just for personal use, you may wish to set the ~/.R/Makevar
information for R via:

https://cran.r-project.org/doc/manuals/r-release/R-admin.html#OS-X-packages


VER=-4.8

CC=gcc$(VER)

CXX= g++$(VER)

CFLAGS=-mtune=native -g -O2 -Wall -pedantic -Wconversion

CXXFLAGS=-mtune=native -g -O2 -Wall -pedantic -Wconversion

FLIBS=-lgfortran



Sincerely,



JJB



*From:* rcpp-devel-bounces at lists.r-forge.r-project.org [mailto:
rcpp-devel-bounces at lists.r-forge.r-project.org] *On Behalf Of *
aakremena at aol.com
*Sent:* Monday, March 14, 2016 10:01 AM
*To:* rcpp-devel at lists.r-forge.r-project.org
*Subject:* [Rcpp-devel] fatal error: 'omp.h' file not found



Dear Rcpp development list members,

I am trying to use OpenMP with Rcpp.  The code (placed in
omp_experiment.cpp file) is pretty basic:

#include <RcppArmadillo.h>
#include <omp.h>

//[[Rcpp::plugins(openmp)]]
//[[Rcpp::depends(RcppArmadillo)]]
using namespace Rcpp;

// [[Rcpp::export]]
int timesTwo(int x) {
   return x * 2;
}



Once I try to compile the file I get the error output

clang: warning: argument unused during compilation: '-fopenmp'
omp_experiment.cpp:2:10: fatal error: 'omp.h' file not found
#include <omp.h>
         ^
1 error generated.
make: *** [omp_experiment.o] Error 1
clang++ -I/Library/Frameworks/R.framework/Resources/include -DNDEBUG
-I/usr/local/include -I/usr/local/include/freetype2 -I/opt/X11/include
-I"/Library/Frameworks/R.framework/Versions/3.2/Resources/library/Rcpp/include"
-I"/Library/Frameworks/R.framework/Versions/3.2/Resources/library/RcppArmadillo/include"
-I"/Users/anguelgrigorov/Documents/Business/MISO/R/Functions/Trading/Experiments"
-fopenmp  -fPIC  -Wall -mtune=core2 -g -O2  -c omp_experiment.cpp -o
omp_experiment.o
Error in
Rcpp::sourceCpp("Documents/Business/MISO/R/Functions/Trading/Experiments/omp_experiment.cpp")
:
  Error 1 occurred building shared library.

*My QUESTION: How to configure OpenMP to work with Rcpp on my system?*

I am working with RStudio, version 0.98.945 on Mac OS X Mavericks.

Every insight into this will be highly appreciated.

Thank you very much in advance.

Anguel


P.S. I've done some reading on the Internet that advised me to check
whether omp.h is even available on my laptop (MacBook Pro).  I have used OS
X
        locate "omp.h" command that proved that omp.h is indeed available
in 4 locations:


/usr/local/Cellar/gcc/5.3.0/lib/gcc/5/gcc/x86_64-apple-darwin13.2.0/5.3.0/include/omp.h

/usr/local/Cellar/gcc6/6-20160124/lib/gcc/6/gcc/x86_64-apple-darwin13.2.0/6.0.0/include/omp.h
/usr/local/lib/gcc/x86_64-apple-darwin13.0.0/4.8.2/include/omp.h
/usr/local/lib/gcc/x86_64-apple-darwin13.1.0/4.9.0/include/omp.h