Matlab Mex code not compiling - c++

Question

I am rewriting some of my matlab code using mex and C++ to make it read large files in faster. I am trying to compile the code and get this error. I am new to mex and would appreciate some help in discovering why the code won't compile. Thanks in advance.
>> mex -v read_svm.cpp
**************************************************************************
Warning: Neither -compatibleArrayDims nor -largeArrayDims is selected.
Using -compatibleArrayDims. In the future, MATLAB will require
the use of -largeArrayDims and remove the -compatibleArrayDims
option. For more information, see:
http://www.mathworks.com/help/matlab/matlab_external/upgrading-mex-files-to-use-64-bit-api.html
**************************************************************************
-> mexopts.sh sourced from directory (DIR = $PREF_DIR)
FILE = /Users/anb/.matlab/R2013a/mexopts.sh
----------------------------------------------------------------
-> MATLAB = /Applications/MATLAB_R2013a.app
-> CC = xcrun -sdk macosx10.7 clang
-> CC flags:
CFLAGS = -fno-common -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7 .sdk -mmacosx-version-min=10.7 -fexceptions
CDEBUGFLAGS = -g
COPTIMFLAGS = -O2 -DNDEBUG
CLIBS = -L/Applications/MATLAB_R2013a.app/bin/maci64 -lmx -lmex -lmat -lstdc++
arguments = -DMX_COMPAT_32
-> CXX = xcrun -sdk macosx10.7 clang++
-> CXX flags:
CXXFLAGS = -fno-common -fexceptions -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk -mmacosx-version-min=10.7
CXXDEBUGFLAGS = -g
CXXOPTIMFLAGS = -O2 -DNDEBUG
CXXLIBS = -L/Applications/MATLAB_R2013a.app/bin/maci64 -lmx -lmex -lmat -lstdc++
arguments = -DMX_COMPAT_32
-> FC = gfortran
-> FC flags:
FFLAGS = -fexceptions -m64 -fbackslash
FDEBUGFLAGS = -g
FOPTIMFLAGS = -O
FLIBS = -L/Applications/MATLAB_R2013a.app/bin/maci64 -lmx -lmex -lmat -L -lgfortran -L -lgfortranbegin
arguments = -DMX_COMPAT_32
-> LD = xcrun -sdk macosx10.7 clang
-> Link flags:
LDFLAGS = -arch x86_64 -Wl,-syslibroot,/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk -mmacosx-version-min=10.7 -bundle -Wl,-exported_symbols_list,/Applications/MATLAB_R2013a.app/extern/lib/maci64/mexFunction.map
LDDEBUGFLAGS = -g
LDOPTIMFLAGS = -O
LDEXTENSION = .mexmaci64
arguments =
-> LDCXX =
-> Link flags:
LDCXXFLAGS =
LDCXXDEBUGFLAGS =
LDCXXOPTIMFLAGS =
LDCXXEXTENSION =
arguments =
----------------------------------------------------------------
-> xcrun -sdk macosx10.7 clang++ -c -I/Applications/MATLAB_R2013a.app/extern/include -I/Applications/MATLAB_R2013a.app/simulink/include -DMATLAB_MEX_FILE -fno-common -fexceptions -arch x86_64 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk -mmacosx-version-min=10.7 -DMX_COMPAT_32 -O2 -DNDEBUG "read_svm.cpp"
-> xcrun -sdk macosx10.7 clang -O -arch x86_64 -Wl,-syslibroot,/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.7.sdk -mmacosx-version-min=10.7 -bundle -Wl,-exported_symbols_list,/Applications/MATLAB_R2013a.app/extern/lib/maci64/mexFunction.map -o "read_svm.mexmaci64" read_svm.o -L/Applications/MATLAB_R2013a.app/bin/maci64 -lmx -lmex -lmat -lstdc++
Undefined symbols for architecture x86_64:
"_mexFunction", referenced from:
-exported_symbol[s_list] command line option
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
mex: link of ' "read_svm.mexmaci64"' failed.
Error using mex (line 206)
Unable to complete successfully.

Answer 1

Do you have a void mexFunction(int nout, mxArray* pout[], int nin, const mxArray* pin[]))
defined in read_svm.cpp file?
Matlab expects your mex file to have a function with that signiture in your code. This is the function it then calls when you execute the mex file.