无法使用Xcode版本4.3.2在Mac OS X Lion 10.7.5上运行Matlab Mex文件

Question

When I am trying to run c++ codes on matlab, I use the following commands:

mex '-setup' (Then I select the following two options which are: 1: /Applications/MATLAB_R2011a_Student.app/bin/gccopts.sh : Template Options file for building gcc MEX-files

and 2: /Applications/MATLAB_R2011a_Student.app/bin/mexopts.sh : Template Options file for building MEX-files via the system ANSI compiler

When I select either one and select a mex file by writing the following:mex mextest1p0.cpp, I get these error messages:

/Applications/MATLAB_R2011a_Student.app/bin/mex: line 1041: g++-4.2: command not found

How can I fix this. Note: I have seen a couple post about this problem and I've tried various solutions, but nothing is working

Answer 1

You need to install a compiler -- namely G++ (the GNU C++ compiler). On OS X, the easiest way to do is this is by installing the XCode Command Line Developer Tools -- open up XCode, go to preferences, choose downloads, and then install the command line tools. If Matlab still can't find G++, you've got a path problem (and tell us about it) -- the solution is then probably in your gccopts script.

Answer 2

You don't actually need to install all of Xcode if you don't want to, I believe. It takes up a lot of hard drive space. You will need (1) an Apple Developer account (free for students). You can then (2) go to the downloads page at developer.apple.com and get just the Command Line Tools download for your version of OS X (the last to these for 10.7 was in March 2013 – it's on the third page of downloads currently). Run the installer for this.

Then you'll need to (3) edit your mexopts.sh file. You'll need to do this if you have Xcode or not. Type the following in your Matlab command window:

edit([matlabroot '/bin/mexopts.sh'])

Make a copy of the file that opens in case you screw up. You'll need to edit the file based on your system and the complier included with the Command Line Tools (you can try getting the versions by running cc -v and c++ -v or similar in Terminal.app). Look for the section related to OS X. You'll need to set the following items (these are from Matlab R2012b and have changed slightly since, but I'm guessing you're using an older version):

CC='llvm-gcc-4.2'

or maybe just

CC='gcc-4.2'

and

SDKROOT='/'
MACOSX_DEPLOYMENT_TARGET='10.7'

If you're using Xcode, the SDKROOT should probably be '/Developer/SDKs/MacOSX10.7.sdk' . For the C++ section just below you'll probably need

CXX='llvm-g++-4.2'

or

CXX='g++-4.2'

(4) Finally, save your edited mexopts.sh file and run the following in the Matlab command window:

mex -setup

Choose your file (press 1 probably) and choose yes ([y]). You should now be able to compile using the mex function.