Making mex work with R2012b and MacOS 10.9.2

I can not compile some matlab functions in simulink model. I modify the mexopts.sh file

        CC='llvm-gcc'
        CXX='llvm-g++'
        SDKROOT='/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/'

        MACOSX_DEPLOYMENT_TARGET='10.9'
        ARCHS='x86_64'

Here's the error comment:

/Applications/MATLAB_R2012b.app/bin/mex -c -O -DMATLAB_MEX_FILE -I/Applications/MATLAB_R2012b.app/toolbox/stateflow/stateflow/../../../simulink/include -I/Applications/MATLAB_R2012b.app/toolbox/stateflow/stateflow/../../../extern/include -I/Applications/MATLAB_R2012b.app/stateflow/c/mex/include -I/Applications/MATLAB_R2012b.app/stateflow/c/debugger/include simulation_sfun.c In file included from simulation_sfun.c:3: In file included from ./simulation_sfun.h:6: In file included from /Applications/MATLAB_R2012b.app/stateflow/c/mex/include/sfc_sf.h:33: In file included from /Applications/MATLAB_R2012b.app/toolbox/stateflow/stateflow/../../../simulink/include/mwmathutil.h:23: /Applications/MATLAB_R2012b.app/toolbox/stateflow/stateflow/../../../extern/include/tmwtypes.h:819:9: error: unknown type name 'char16_t' typedef char16_t CHAR16_T; ^ 1 error generated.

    mex: compile of ' "simulation_sfun.c"' failed.

gmake: * [simulation_sfun.o] Error 1

Is it possible to make mex work with R2012b and MacOS 10.9.2 and Xcode 5.1.1 ? Thanks.