How can i compile a stateflow file in MATLAB 8.1 R2013a?

Hello everybody!

I have some problems to compile a stateflow project, it gives me the following errors:

Making simulation target "Switch_ON_OFF_sfun", ...

/Applications/MATLAB_R2013a.app/bin/mex -c -O  -DMATLAB_MEX_FILE    -I/Applications/MATLAB_R2013a.app/stateflow/c/mex/include -I/Applications/MATLAB_R2013a.app/stateflow/c/debugger/include   Switch_ON_OFF_sfun.c
xcodebuild: error: SDK "macosx10.7" cannot be located.
xcrun: error: unable to find utility "clang", not a developer tool or in PATH

    mex: compile of ' "Switch_ON_OFF_sfun.c"' failed.
gmake: *** [Switch_ON_OFF_sfun.o] Error 1

I have tryed to follow this instructions:

http://www.mathworks.com/matlabcentral/answers/103904

but with no effect. Unfortunatly i upgraded my xcode to version 5 before you know that would give all these problems, so how can i resolve this problem?