Symbolic link to compile code using 32-bit libraries on 64-bit Ubuntu 12.10

I am trying to get mex C code using Matlab 32 bit 2012a on Ubuntu 12.10 64 bit

I have downloaded all possible libraries (gcc 4.7, build-essential, libs-32, etc.) however I am getting the following error

/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.7/libstdc++.so when searching for -lstdc++
/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.7/libstdc++.a when searching for -lstdc++
/usr/bin/ld: cannot find -lstdc++
/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.7/libgomp.so when searching for -lgomp
/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.7/libgomp.a when searching for -lgomp
/usr/bin/ld: cannot find -lgomp
/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.7/libgcc_s.so when searching for -lgcc_s
/usr/bin/ld: cannot find -lgcc_s
collect2: error: ld returned 1 exit status

      

        
        
        
      

    

I found that this problem can be solved by setting a symbolic link from 64-bit libraries to 32-bit ones. I tried to create different links but couldn't finish compiling.

Thanks in advance.

UPDATE 1

gcc-multilib is missing, so after

sudo apt-get install gcc-multilib 

      

        
        
        
      

    

I am getting the following errors:

Warning: You are using gcc version "4.7.2-2ubuntu1)".  The version
     currently supported with MEX is "4.4.6".
     For a list of currently supported compilers see: 
     http://www.mathworks.com/support/compilers/current_release/

/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.7/libstdc++.so when searching for -lstdc++
/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.7/libstdc++.a when searching for -lstdc++
/usr/bin/ld: cannot find -lstdc++
collect2: error: ld returned 1 exit status

      

        
        
        
      

    

My mexopts.sh looks like

CC='gcc'
CFLAGS='-ansi -D_GNU_SOURCE'
CFLAGS="$CFLAGS -fPIC -pthread -m32"
CFLAGS="$CFLAGS  -fexceptions"
CFLAGS="$CFLAGS -D_FILE_OFFSET_BITS=64" 
CLIBS="$RPATH $MLIBS -lm"
COPTIMFLAGS='-O -DNDEBUG'
CDEBUGFLAGS='-g'
CLIBS="$CLIBS -lstdc++"

      

        
        
        
      

    

there is -m32, however I am not sure if it should be written that way. Can anyone please elaborate on how to edit mexopts.sh to make Matlab look at 32 bit libraries?

UPDATE 2

after looking at Binding using g ++ can't find -lstdc ++

I tried to install g ++ - multilib

sudo apt-get install g++-multilib 

      

        
        
        
      

    

Now the errors look like:

/usr/bin/ld: i386:x86-64 architecture of input file `bin/fv_cache.o' is incompatible with i386 output
/usr/bin/ld: i386:x86-64 architecture of input file `bin/obj_func.o' is incompatible    with i386 output
...