Debugging C++ mex files in Xcode 7 on El Capitan

5 views (last 30 days)
I have just migrated to MAC OS, and am trying to debug a mex file for the first time. I'm using MATLAB R2015b and Xcode 7.0.1 on OS X 10.11 (El Capitan). I've followed the instructions here:
When I hit Command-R I see "Running StartMATLAB : debug" in the status bar at the top of the Xcode window. However, shortly afterwards that changes to "Finished StartMATLAB : debug", and MATLAB never actually appears.
Another thing I've tried is attaching Xcode to the MATLAB process. If I have the JVM running, it continuously hits breakpoints in assemble code, even before I call my code. If I run with the -nojvm option and attach the debugger, it doesn't stop on my breakpoints.
I should add that I'm compiling the mex file from within MATLAB. Perhaps Xcode is not watching the mex library that gets built, unlike if I do the same thing in Visual Studio.
Incidentally, I use the fix described here to use Xcode 7 and El Capitan.
Any help much appreciated.

Answers (2)

Oliver Woodford
Oliver Woodford on 23 Oct 2015
Edited: Oliver Woodford on 15 Nov 2016
I have been able to hit a breakpoint in my mex code, within the Xcode IDE, by doing the following steps:
  1. Building the mex file from within Xcode
  2. Starting MATLAB in a terminal window by calling "matlab -nojvm"
  3. Attaching Xcode to the MATLAB process
  4. Putting a breakpoint in my mex function
  5. Calling my mex function from MATLAB
This isn't ideal because I had to compile the mex library/application from within Xcode, rather than the normal way I do it, which is just on the MATLAB command line with my own special script. I think there must be a command line option for the compiler which I'm not using in my script, but the Xcode project is. I use only the -g option. The Xcode project uses:
-x c++ -arch x86_64 -fmessage-length=0 -fdiagnostics-show-note-include-stack
-fmacro-backtrace-limit=0 -std=gnu++11 -stdlib=libc++ -fmodules -gmodules
-fmodules-prune-interval=86400 -fmodules-prune-after=345600
-fmodules-validate-once-per-build-session -Wnon-modular-include-in-framework-module
-Werror=non-modular-include-in-framework-module -Wno-trigraphs
-fpascal-strings -O0 -fno-common -Wno-missing-field-initializers
-Wno-missing-prototypes -Werror=return-type -Wunreachable-code
-Werror=deprecated-objc-isa-usage -Werror=objc-root-class
-Wno-non-virtual-dtor -Wno-overloaded-virtual -Wno-exit-time-destructors
-Wno-missing-braces -Wparentheses -Wswitch -Wunused-function -Wno-unused-label
-Wno-unused-parameter -Wunused-variable -Wunused-value -Wempty-body
-Wconditional-uninitialized -Wno-unknown-pragmas -Wno-shadow -Wno-four-char-constants
-Wno-conversion -Wconstant-conversion -Wint-conversion -Wbool-conversion
-Wenum-conversion -Wshorten-64-to-32 -Wno-newline-eof -Wno-c++11-extensions -DMATLAB_MEX_FILE -D_MATLAB_=806
-isysroot /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk
-fasm-blocks -fstrict-aliasing -Wdeprecated-declarations -Winvalid-offsetof
-mmacosx-version-min=10.11 -g -fvisibility-inlines-hidden -Wno-sign-conversion

Oliver Woodford
Oliver Woodford on 15 Nov 2016
I build the mex file as a command line project in Xcode, using the following custom build settings:
I then copy the mex file to where it should be with a build phase copy:

Categories

Find more on MATLAB Compiler in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!