Reusing MXE Octave to build Octave for Mac OS X

It is interesting to see that MXE Octave has become more capable than the original MXE. It can not only be used to cross-compile Octave, but is now capable of natively compiling Octave (mingw and msvc) as well. Since I have used MXE Octave to complete the first half of the project to cross-compile Octave to Windows, it is wise to re-use the same to natively compile Octave under Mac OS X. The builds, as far as I can say are supported on a range of platforms. This wouldn’t have been possible if I were to build an app bundle.

On the Mac I am using for my work, config.guess returns x86_64-apple-darwin12.2.1. Also the command gcc -dumpmachine returns i686-apple-darwin11. Hence the target I am using to compile Octave is i686-apple-darwin11. Using x86_64-apple-darwin12.2.1 as the target results in many errors like "Undefined symbols for architecture x86_64: "

I am writing some of the things I did to build a very basic version of Octave (lacks support for many libraries) for Mac OS X using my repo mxe-octave-anirudha.

• Since GCC doesn’t work for native builds yet, so I used the system GCC provided by XCode. The variable USE_SYSTEM_GCC is automatically set to yes if we pass the --enable-native-build option to configure.
• Till now I have compiled everything using the cross compile configurations making changes wherever required. On my system, the configure was unable to find the Fortran compiler. I had to manually add the path MXE_F77 := /opt/local/bin/gfortran-mp-4.7 in the Makefile as well as add set(CMAKE_Fortran_COMPILER /opt/local/bin/gfortran-mp-4.7) in usr/x86_64-apple-darwin12.2.1/share/cmake/mxe-conf.cmake. This was necessary for packages like BLAS, Lapack, and Octave. I will later commit a patch to detect the Fortran compiler path automatically.
• The compilation is likely to stop when dbus is built. This is because dbus needs root privileges during build, else it will throw “Permission denied” error. Running sudo make dbus works fine.
• Since we are building for a 64-bit target, we must use ./Configure darwin64-x86_64-cc instead of ./config to build package openssl.
• Compiling Qt succeeds but MXE_PKG_CONFIG is unable to extract the QT_LDFLAGS and QT_LIBS. It is perhaps the reason why the build of Octave fails when GUI is enabled. The variable (PKG)_CONFIGURE_ENV must be set correctly for Mac OS X. To get past Qt build I used the MSVC configurations. The command pkg-config --libs-only-L ./usr/x86_64-apple-darwin12.2.1/lib/pkgconfig/QtCore.pc returns nothing, which might be the reason why Octave doesn’t build with GUI.
• I had to disable Readline support by adding --disable-readline in src/octave.mk. Since my repo uses Octave 3.7.5 I had to add the patch to make ctrl-c abort the actual octave command in linux (bug #37672). In Octave 3.7.6, the patch has been merged, so it must be removed from the src folder.

After the build completed, Octave was configured for “x86_64-apple-darwin12.2.1”. I will be pushing the changesets to my repo soon. Octave can be launched by doing  ./usr/x86_64-apple-darwin12.2.1/bin/octave. It will launch the CLI version of Octave since GUI was disabled during build. Here is a screenshot.