Building OpenFOAM 2.2.2 on OS X with clang

NB! Updated version of the guide can be found in the post Building OpenFOAM on OS X

There are several instructions for building OpenFOAM on OS X (1, 2). They assume that you are using Macports which was not a case with me. So I've decided to build OpenFOAM with clang as it comes with developer tools. My patches are based upon ones by Bernhard Gschaider, basically I've applied his patches, removed Macports stuff and added clang stuff. Patches and build process was tested on OS X 10.9 with clang --version:

Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)
Target: x86_64-apple-darwin13.0.0
Thread model: posix

So, to build OpenFOAM you need:

1. Download OpenFOAM and Third-Party source packs here.
2. Create a disk image with Disk Utility. One needs this image to create case sensitive file system (see 1 or 2 for instructions with pictures).
3. Download patches for OpenFOAM and Third-Party source packs. They assume you are building 64-bit version of the code as there're no wmake rules for 32-bit compilation.
4. Mount created disk image to $HOME/OpenFOAM
5. Unpack source packs to $HOME/OpenFOAM
6. Copy patch files to source folders (OpenFOAM-2.2.2-1387556919.patch to OpenFOAM-2.2.2, ThirdParty-2.2.2-1387556964.patch to ThirdParty-2.2.2).
7. Apply patches with git apply [patch file name] command. In addition to changing contents of the files git sets modes so you won't need to do chmod 0755 [file] on executable files created by the patches.
8. Edit $HOME/OpenFOAM/OpenFOAM-2.2.2/ets/bashrc file to correspond to your system. I've tested build with OPENMPI (1.6.3, in ThirdParty source pack), and with SYSTEMOPENMPI (1.7.3, installed with Homebrew, I guess if you're using Macports you'll need to modify wmake rules).
9. Source bashrc with source etc/bashrc
10. Now you can execute Allwmake script to build OpenFOAM.

To mount disk image and source OpenFOAM's bashrc file automatically each time you launch Terminal one can add following lines to $HOME/.profile file:

# OpenFOAM
if [ -f $HOME/.OpenFOAM ]; then
    OF_VER=$(cat $HOME/.OpenFOAM)
    if [ ! -f $HOME/OpenFOAM/OpenFOAM-$OF_VER/etc/bashrc ]; then
        hdiutil attach -quiet -mountpoint $HOME/OpenFOAM OpenFOAM-$OF_VER.dmg &&
            . $HOME/OpenFOAM/OpenFOAM-$OF_VER/etc/bashrc
    else
        . $HOME/OpenFOAM/OpenFOAM-$OF_VER/etc/bashrc
    fi
fi

And create $HOME/.OpenFOAM file with OpenFOAM version in it with:

echo '2.2.2' > $HOME/.OpenFOAM

Now you can test installation with standard icoFoam run:

$ mkdir -p $FOAM_RUN
$ run
$ cp -r $FOAM_TUTOTALS/incompressible/icoFoam/cavity .
$ cd cavity
$ blockMesh
$ icoFoam

Also maybe it's worth to move $FOAM_RUN folder somewhere outside of disk image and create symlink.

That's it.