specific mex compiler matlab linux 64 bit

HI everybody, I am trying to set up a specific compiler for my mexfiles in matlab under debian 64bit. First of all I have tried to run

mex -setup -v

but it does not provide any option as I expected

Verbose mode is on.
... Looking for compiler 'gcc' ...
... Executing command 'which gcc' ...Yes ('/usr/bin/gcc').
... Executing command 'gcc -print-file-name=libstdc++.so' ...Yes ('/usr/lib/gcc/x86_64-linux-gnu/6/libstdc++.so').
Found installed compiler 'gcc'.
... Looking for compiler 'gcc' ...
... Executing command 'which gcc' ...Yes ('/usr/bin/gcc').
... Executing command 'gcc -print-file-name=libstdc++.so' ...Yes ('/usr/lib/gcc/x86_64-linux-gnu/6/libstdc++.so').
Found installed compiler 'gcc'.
MEX configured to use 'gcc' for C language compilation.
Warning: The MATLAB C and Fortran API has changed to support MATLAB
   variables with more than 2^32-1 elements. You will be required
   to update your code to utilize the new API.
   You can find more information about this at:
   http://www.mathworks.com/help/matlab/matlab_external/upgrading-mex-files-to-use-64-bit-api.html.

To choose a different language, select one from the following:
 mex -setup C++ 
 mex -setup FORTRAN

Then I tried to copy /usr/local/MATLAB/R2017a/bin/mexopts.sh in ~/.matlab/R2017a/mexopts.sh and modify the configurations as in

              CC='/usr/bin/gcc-4.9'

and analogously for g++. However the following output shows that this didn't work, either

>> cc = mex.getCompilerConfigurations('C','Selected')

cc = 

    CompilerConfiguration with properties:

               Name: 'gcc'
       Manufacturer: 'GNU'
           Language: 'C'
            Version: ''
           Location: '/usr/bin/gcc'
          ShortName: 'gcc'
           Priority: 'A'
            Details: [1×1 mex.CompilerConfigurationDetails]
         LinkerName: ''
      LinkerVersion: ''
             MexOpt: '/home/anicastro/.matlab/R2017a/mex_C_glnxa64.xml'

and /usr/bin/gcc points to gcc 6.3. I tried also by changing the file in /usr/local/MATLAB/R2017a/bin/mexopts.sh but the result is the same.

I have little experience with mex files, how can I solve this?

Cheers

Andrea

Answer 1

[Sangeetha Jayaprakash]

It looks like you are trying to use gcc version 4.9 compiler with the "mex" function.

1. To view all the MATLAB compatible compilers for compiling C code, execute the following:

>> mex -setup C

2. If you are unable to view the GCC-4.9 compiler in the list of available compilers, use the GCC option along with the mex command to point at a supported compiler version. Also, make use of the verbose option (-v flag) in order to view the current settings of GCC, and confirm the changes made as shown below:

>> mex -v GCC='path/to/gcc/bin/gcc-4.9' path/to/somefile.c

I hope this works for you.

[Andrea Nicastro]

Hi, thank you for the answer.

1. As I was saying in my original post, your suggested solution is the first one I tried, but it does not work.

2. I already tried this solution, but it is highly unpractical for large toolboxes that provide a compilation mechanism.

I'll try to see if there is another way to proceed