Why can't MEX find a supported compiler in MATLAB R2016a linux?

Does anybody know why I get the error,

Error using mex
No supported compiler or SDK was found. For options, visit
http://www.mathworks.com/support/compilers/R2016a/glnxa64.html.

I'm using matlab R2016a on ubuntu linux with gcc 4.7, which should be supported. Also tried earlier with gcc 4.8, same error.

>>!gcc -v

Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.7.3-12ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs --enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.7 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-gnu-unique-object --disable-libmudflap --enable-plugin --with-system-zlib --enable-objc-gc --with-cloog --enable-cloog-backend=ppl --disable-cloog-version-check --disable-ppl-version-check --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-12ubuntu1) 

>>mex -setup

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. In the near future
   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

thanks!

-Mike

[Geoff Hayes]

Mike - what is written to the console when you enable verbosity?

 >> mex setup -v

Answer 1

[Mike Wehr]

Figured it out. I was trying to compile a .cpp file, so I needed to install the g++-4.7 compiler, not gcc.

The solution is to run the commands:

sudo apt-get install g++-4.7

sudo ln -s /usr/bin/g++-4.7 /usr/bin/g++

Answer 2

[Amin Ullah Khan]

mex -setup -v
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/5/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/5/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:
   https://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