building

Linux, Unix-like systems
Packaging systems
- spack
- easybuild
Darwin (Mac-OS)
- Known issues
Windows (cross-compiled)
Tuning

Linux, Unix-like systems

Version	Build
v2112	Build
v2106	Build
v2012	Build
v2006	Build
v1912	Build
v1906	Build
older	obsolete

Packaging systems

System	Links	Status	Notes
spack	package openfoam	Actively maintained by OpenCFD	notes
EasyBuild	package OpenFOAM	Maintained independently, with input from OpenCFD
debian, RPM	See precompiled	Actively maintained by OpenCFD

spack

The installation of OpenFOAM with spack will generally require the latest (development version) of spack. If this is available, you can install OpenFOAM in various configurations and dependencies, but typically can simply install directly:

$ spack install openfoam

easybuild

The installation of OpenFOAM with easybuild will generally require the latest (development version) of easybuild.

Darwin (Mac-OS)

The support for Darwin is complete, but less well tested than Linux.

Compilation uses the system clang compiler.
The Darwin build (and operation) requires a case-sensitive file system.
(For older systems, this can be created as a disk image and mounted)

Known issues

CGAL

ThirdParty CGAL will normally need to be compiled without mpfr/gmp. This should be done manually prior to building OpenFOAM or other ThirdParty. For example,
```
cd $WM_THIRD_PARTY_DIR
./makeCGAL gmp-none mpfr-none
```
The wmake/rules/darwin64Clang/cgal file avoids references to gmp/mpfr libraries.

Windows (cross-compiled)

Windows 64bit binaries can be generated on 64bit Linux by cross-compilation.

Tuning

Different configurations

Sometimes it is useful to switch between entire sets of configuration preferences without re-editing the files each time. This is the purpose of the FOAM_CONFIG_ETC variable. It specifies an absolute path, or a path relative to the project directory where various configuration files can be found. These are selected in preference to the normal shipped configuration files.

This allows swapping in a set of different preferences without modifying the regular settings. See cross-compilation for an example of its use.

Different compiler versions

By default, OpenFOAM handles newer/older non-system compilers as ThirdParty installations and uses the combination of WM_COMPILER and WM_COMPILER_TYPE to select them. In some cases, however, it is more convenient to install prebuilt compiler binaries as system compilers (e.g., using deb or rpm packages). These compilers are typically distinguished by an additional version suffix (eg, gcc-11, clang-13, clang-13.0 etc).

The WM_COMPILE_CONTROL environment can be used to add the additional resolution necessary. For example,

export WM_COMPILER=Gcc
export WM_COMPILE_CONTROL="version=11"

This will add the suffix -11 to the regular compiler names. Note, that is normally good practice to add some compiler version information into the build name as well. For example,

export WM_COMPILER=Clang130
export WM_COMPILE_CONTROL="version=13.0"

Be certain to verify that the rules have actually been set as expected:

wmake -show-cxx
wmake -show-path-cxx

If this change represents your standard default compiler definition, then place the information into the etc/prefs.sh file (see the etc/bashrc file for some details) and re-source your OpenFOAM environment. If you would like to selectively enable this compiler definition, a common means is to place the same definition information into a user configuration file (for example, ~/.OpenFOAM/clang130) and then specify that configuration when sourcing your OpenFOAM environment. For example,

source /path/to/OpenFOAM-version/etc/bashrc  clang130

The bashrc will locate and use the configuration file, after which the compiler will be properly selected. Again, to verify everything has actually been set properly:

wmake -show-cxx
wmake -show-path-cxx

Processor-specific handling

Processor-specific builds are typically handled by creating a new compilation option. For example, to create Broadwell-specific options:

    $ cd wmake/rules/linux64Gcc
    $ cp c++Opt c++OptBdw

edit this file and then use WM_COMPILE_OPTION=OptBdw in the prefs.sh before re-sourcing the OpenFOAM environment.

Since OpenFOAM is purely C++ code, there is no need to apply special processor-specific optimizations for C code (the regular -O2 optimization is fine) since these components only appear as part of the wmake build toolchain itself.