GCC C/C++ MEX Matlab R2015 Mac OS X (with OpenMP) doesn't work

Question

I\'m trying to compile a very simple MEX file in Matlab using GCC/G++... First I checked that this is already installed in matlab by: !which gcc

output: /usr/bin/gcc

Answer 1

Finally, I found a proper way to solve it... First, the file mexopts.sh doesn't appear in the folder by default, is necessary to open a terminal and look for it and create it (then Matlab will redirect to it automatically when compiling with MEX):

find ~/ -name 'mexopts.sh' 

and will appear:

/Users/FOO//.Trash/MATLAB_R2014a.app/bin/mexopts.sh

Then, copy it as:

cp /Users/FOO//.Trash/MATLAB_R2014a.app/bin/mexopts.sh ~/.matlab/R2014a

then go to the folder cd ~/.matlab/R2014a and change permissions for your user as:

chmod u+rwx mexopts.sh

then, open it with your default text editor (Sublime text recommended) as:

open mexopts.sh

and edit the following: Change where appears macosx10.7 to your current version, in my case macos10.10 then, modify the following lines as describen in (http://www.mathworks.com/matlabcentral/newsreader/view_thread/334250):

# CC='xcrun -sdk macosx10.7 clang' #OLD
CC='xcrun /usr/local/bin/gcc' #NEW



# CXX='xcrun -sdk macosx10.7 clang++' #OLD
 CXX='xcrun /usr/local/bin/g++' #NEW



# CLIBS="$CLIBS -lstdc++" #OLD
CLIBS="$CLIBS -lstdc++ -I/usr/local/lib -lgomp" #directory <-I/usr/local/lib> #NEW
#CXXLIBS="$MLIBS -lstdc++" #OLD
CXXLIBS="$MLIBS -lstdc++ -I/usr/local/lib -lgomp" #NEW

IMPORTANT NOTE: Make sure that your current G++/G++4.9 is able to compile with OpenMP, trying to include in a hello world file doing in the command line:

g++-4.9 -o test hello.cpp -fopenmp

or

g++ -o test hello.cpp -fopenmp

is also possible that a file is corrupted and is necessary to do Can not compile fortran because dyld: Library not loaded :

brew rm cloog

brew install cloog

(But check first)...

Is also possible that if you're not able to compile with OMP is necessary to do first a couple of things as described here (Compile OpenMP programs with gcc compiler on OS X Yosemite): 1. Got a new gcc complier from http://hpc.sourceforge.net/ 2. Place a new executable folder by $ sudo tar -xvf gcc-4.9-bin.tar -C / 3. Switched to it by export PATH=/usr/local/bin:$PATH

Finally, try to compile your MEX file with:

mex hello.cpp COMPFLAGS="/openmp $COMPFLAGS"

That's it ... .