Up until Matlab 2013b, one could modify the C/C++ mex compilation flags by editing the mexopts.sh file, usually found in ~/.matlab/mexopts.sh. A common example nowadays is adding the -std=c++11 option to compile C++ code from the C++11 standard (which has some awesome features). To do that in Matlab 2013 and below, you would simply add the flag to the CXXFLAGS variable.
In Matlab 2014, however, things got a little bit more complicated than that. Googling a little I found that now the options were stored in XML files called something like mex_C_glnxa64.xml or mex_C++_glnxa64.xml, but these were nowhere to be found in my system, until I finally realized you have to call mex setup before to create them.
The final steps are as follow:
- Run
mex -setup C++ormex -setup C, depending on which language you are gonna compile. This will create the corresponding XML file. - Open the file
~/.matlab/mex_C++_glnxa64.xmlor~/.matlab/mex_C_glnxa64.xml. In some versions of Matlab it’s in~/.matlab/R2014a/mex_C++_glnxa64.xml. - Edit the CXXFLAGS line to something like:
CXXFLAGS="-ansi -fexceptions -fPIC -fno-omit-frame-pointer -pthread -std=c++11"
And you’re good to go!
You might also need to change the compiler used to a non-default one. You can do so by calling mex with mex GCC='/path/to/bin/g++' you_file.cpp.