Alien

All Alien world into one git repository. This repository aims at easing development by compiling together Alien's core, its high level dependencies and its plugins.

How to use ?

Simply clone this repository.

git clone https://github.com/arcaneframework/alien.git
cd alien

After, you can run CMake (at least version 3.18).

mkdir build && cd build
cmake ..

Useful CMake options:

• ALIEN_FRAMEWORK_EXTERNAL, compile each subproject separately, OFF by default
• ALIEN_PLUGIN_GINKGO, whether Ginkgo plugin is compiled, OFF by default
• ALIEN_PLUGIN_HYPRE, whether hypre plugin is compiled, OFF by default
• ALIEN_PLUGIN_TRILINOS, whether Trilinos plugin is compiled, OFF by default
• ALIEN_USE_HDF5, whether HDF5 support is enabled, OFF by default.

We can mention also other generic CMake options :

• CMAKE_EXE_LINKER_FLAGS="-Wl,--no-as-needed", useful on debian based linux distribution (like ubuntu), as without linker drops libraries that are not explicitly referenced, breaking our plugin interface.
• CMAKE_VERBOSE_MAKEFILE=ON

Requirements

Alien requires a recent build environment:

• recent CMake (>= 3.18)
• C++ compiler that supports C++-17 (gcc, llvm/clang, intel)
• MPI
• boost, at least with timer and program options components enabled
• glib2
• BLAS
• Arccon
• Arccore
• Google Tests, for unit tests

On Ubuntu-20.04, installing these packages is sufficient for running hypre solvers:

apt-get install build-essential cmake gcc g++ gdb \
       libhypre-dev \
       libboost-dev libboost-program-options-dev libgtest-dev libglib2.0-dev

For GoogleTest, one must finish installation by running:

cd $(mktemp -d) && cmake /usr/src/googletest && cmake --build . --target install

How it works ?

This repository contains the following subdirectories:

• src, the main repository for linear algebra,
• plugins, with different plugins for Alien, to call Ginkgo, hypre, PETSc, or Trilinos external libraries.

For git developers, Arccore and Arccon dependencies can be built on the fly by setting ALIENDEV_EMBEDDED to ON.

Documentation generation

Documentation is available on documentation, but can be locally built.

You need a python version 3 with sphinx and breathe modules.

You can easily create a conda environment as following:

cd $ALIEN_ROOT/tools/python
conda env create -f alien-env.yml
conda activate alien-env

Then the CMake flag for documentation has to be activated in the Alien configuration step

cmake -S `pwd`/alien \
      -B `pwd`/build-alien \
      -DALIEN_GENERATE_DOCUMENTATION=ON \
       ....
       
make -C `pwd`/build-alien install
make -C `pwd`/build-alien doc_alien

The documentation is generated in :

firefox `pwd`/build-alien/alien_doc/index.html