Can I build a C++ MEX file using Xcode 5 on Mac OS X 10.9?

I would like to be able to build MEX files using the Xcode 5 IDE on OS X 10.9 (Mavericks) with Matlab 2013b.

I saw this related question involving what was presumably Xcode 4 on an earlier version of OS X and Matlab, but some of the steps seem different or not applicable.

I initially attempted to build the built-in mexcpp.cpp file using Xcode (on my computer, mexcpp.cpp is /Applications/MATLAB_R2013b.app/extern/examples/mex/mexcpp.cpp). Here's what I did:

• Create a new Xcode project (OS X -> Application -> Command Line Tool)
• Call it "mex xcode test", type C++
• Rename main.cpp to mexcpp.cpp
• Copy contents of matlab's mexcpp.cpp to my mexcpp.cpp
• Under Target -> Build Settings, add the following User Header Search Paths:

1. /Applications/MATLAB_R2013b.app/extern/include (non-recursive)

• Under Target -> Build Settings, add the following Library Search Paths:

1. /Applications/MATLAB_R2013b.app/sys/os/maci64 (non-recursive)
2. /Applications/MATLAB_R2013b.app/bin/maci64 (recursive)

• Under Target -> Build Settings, set "Always Search User Paths" to Yes
• Build via Product -> Build

Ignoring the "missing main.cpp" warning, I get the following linker errors:

Undefined symbols for architecture x86_64:
  "_main", referenced from:
     implicit entry/start for main executable
  "_mexErrMsgIdAndTxt", referenced from:
      _mexFunction in mexcpp.o
  "_mxGetPr", referenced from:
      _mexFunction in mexcpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I added some more steps from the instructions at http://www.mathworks.com/help/matlab/matlab_external/custom-building-mex-files.html#f24496

• Under Target -> Build Settings, add preprocessor macro MATLAB_MEX_FILE to both Debug and Release phases

This made no difference.

I thought of trying a few things from the answer to this related question from 2011

• Under Target -> Build Phases -> Link Binary with Libraries, I added several explicit libraries (but shouldn't these be found automatically based on my library search path?):

1. /Applications/MATLAB_R2013b.app/bin/maci64/libeng.dylib
2. /Applications/MATLAB_R2013b.app/bin/maci64/libmx.dylib

This solved my linker problem to mxGetPr, so my linker error message is now shorter:

Undefined symbols for architecture x86_64:
  "_main", referenced from:
     implicit entry/start for main executable
  "_mexErrMsgIdAndTxt", referenced from:
      _mexFunction in mexcpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

Is the solution then to somehow figure out which explicit library files I need for every C++ function that I write? This seems unsustainable, since there are over 500 library files in the /Applications/MATLAB_R2013b.app/bin/maci64 folder. Or am I missing a step in telling Xcode where to find the library files?

And will adding the right library files solve my error involving the _main symbol? Or do I need to somehow tell Xcode to build a library instead of an executable?

What steps am I missing?

Thank you!

[David]

Hi, did you ever solve this problem? I am having the same issues right now. Also, in Xcode 5.1 you can't type in the explicit path to libraries like you did above.

Answer 1

[Bernard]

Hi

I could make it work by setting Mach-O Type to Bundle (in Linking). Also, I used "-lmx -lmex -lmat" in Other Linker Flags to specify the libraries.

[Mike Damianakis]

This worked for me, thank you.