qp2/INSTALL.rst

============
Installation
============

The |qp| can be downloaded on GitHub as an `archive
<https://github.com/LCPQ/quantum_package/releases/latest>`_ or as a `git
repository <https://github.com/LCPQ/quantum_package>`_.

.. code:: bash

  git clone https://github.com/LCPQ/quantum_package


Before anything, go into your :file:`quantum_package` directory and run

.. code:: bash

   ./configure


This script will create the :file:`quantum_package.rc` bash script, which
sets all the environment variables required for the normal operation of the
*Quantum Package*.

Running this script will also tell you which external dependencies are missing
and need to be installed.

When all dependencies have been installed, ( the :command:`configure` will tell you) 
source the :file:`quantum_package.rc` in order to load all environment variables and compile the |QP|. 


Requirements
============

- Linux OS
- Fortran compiler : GNU Fortran, Intel Fortran or IBM XL Fortran
- `GNU make`_
- `Autoconf`_
- `Python`_ > 2.6
- |IRPF90| : Fortran code generator
- |EZFIO| : Easy Fortran Input/Output library generator
- |BLAS| and |LAPACK|
- `Zlib`_
- `GNU Patch`_
- |ZeroMQ| : networking library
- |OCaml| compiler with |OPAM| package manager 
- |Ninja| : a parallel build system


When all the dependencies have been installed, go into the :file:`config`
directory, and copy the configuration file that corresponds to your
architecture. Modify it if needed, and run :command:`configure` with
:option:`configure -c`.

.. code:: bash

   cp ./config/gfortran.example config/gfortran.cfg
   ./configure -c config/gfortran.cfg


.. note::

   The ``popcnt`` instruction accelerates *a lot* the programs, so the
   SSE4.2, AVX or AVX2 instruction sets should be enabled in the
   configuration file if possible.


Help for installing external dependencies
=========================================

Using the :command:`configure` executable
-----------------------------------------

The :command:`configure` executable can help you in installing the minimal dependencies you will need to compile the |QP|. 
The command is to be used as follows: 

.. code:: bash

   ./configure --install <package>

The following packages are supported by the :command:`configure` installer: 

* ninja 
* irpf90 
* zeromq 
* f77zmq
* ocaml  ( :math:`\approx` 10 minutes)
* ezfio 
* docopt 
* resultsFile 
* bats

Example: 

.. code:: bash

   ./configure -i ezfio

.. note::

   When installing the ocaml package, you will be asked the location of where it should be installed.
   A safe option is to enter the path proposed by the |QP|:

   QP>> Please install it here: /your_quantum_package_directory/bin

   So just enter the proposition of the |QP| and press enter.


If the :command:`configure` executable fails to install a specific dependency
-----------------------------------------------------------------------------

If the :command:`configure` executable does not succeed to install a specific dependency, 
there are some proposition of how to download and install the minimal dependencies to compile and use the |QP|


Before doing anything below, try to install the packages with your package manager
(:command:`apt`, :command:`yum`, etc)


Ninja
-----

*Ninja* is a build system (like GNU make), with a focus on speed.

* Download the latest binary version of Ninja
  here : `<https://github.com/ninja-build/ninja/releases/latest>`_

* Unzip the ninja-linux.zip file, and move the ninja binary into
  the :file:`${QP_ROOT}/bin` directory.



IRPF90
------

*IRPF90* is a Fortran code generator for programming using the Implicit Reference
to Parameters (IRP) method. 

* Download the latest version of IRPF90
  here : `<https://github.com/scemama/irpf90/releases/latest>`_ and move
  the downloaded archive in the :file:`${QP_ROOT}/external` directory

* Extract the archive and go into the :file:`irpf90-*` directory to run
  :command:`make`

.. note::

    The :envvar:`IRPF90_PATH` variable may need to be updated in the configuration
    file :file:`${QP_ROOT}/etc/irpf90.rc`.



ZeroMQ and its Fortran binding
------------------------------

*ZeroMQ* is a high-performance asynchronous messaging library.

* Download the latest stable version of ZeroMQ
  here : `<https://github.com/zeromq/libzmq/releases/latest>`_ and move the
  downloaded archive in the :file:`${QP_ROOT}/external` directory

* Extract the archive, go into the :file:`zeromq-*` directory and run
  the following commands

.. code:: bash

   ./configure --prefix="${QP_ROOT}" --without-libsodium
   make
   make install


* Download the Fortran binding
  here : `<https://github.com/zeromq/f77_zmq/releases/latest>`_ and move
  the downloaded archive in the :file:`${QP_ROOT}/external` directory

* Extract the archive, go into the :file:`f77_zmq-*` directory and run
  the following commands

.. code:: bash

   export ZMQ_H=${QP_ROOT}/include/zmq.h
   make
   cp libf77zmq.a ${QP_ROOT}/lib
   cp libf77zmq.so ${QP_ROOT}/lib


* Copy the :file:`f77_zmq_free.h` file in the ``ZMQ`` module as follows:

.. code:: bash

   cp f77_zmq_free.h ${QP_ROOT}/src/ZMQ/f77_zmq.h


Zlib
----

*Zlib* is the compression library used by *gzip*.

* Download the latest version of Zlib here:
  `<https://www.zlib.net/zlib-1.2.11.tar.gz>`_
  and move it in the :file:`${QP_ROOT}/external` directory

* Extract the archive, go into the :file:`zlib-*` directory and run
  the following commands


.. code:: bash

   ./configure --prefix=${QP_ROOT}
   make
   make install



OCaml
-----

*OCaml* is a general purpose programming language with an emphasis on expressiveness and safety.

* Download the installer of the OPAM package manager here :
  `<https://raw.githubusercontent.com/ocaml/opam/master/shell/install.sh>`_
  and move it in the :file:`${QP_ROOT}/external` directory

* If you use OCaml only with the |qp|, you can install the OPAM directory 
  containing the compiler and all the installed libraries in the
  :file:`${QP_ROOT}/external` directory as

  .. code:: bash
       
     export OPAMROOT=${QP_ROOT}/external/opam


* Run the installer

  .. code:: bash
       
     echo ${QP_ROOT}/bin
     ${QP_ROOT}/external/opam_installer.sh --no-backup --fresh

  You the :command:`opam` command can be installed in the :file:`${QP_ROOT}/bin`
  directory. To do this, take the output of ``echo ${QP_ROOT}/bin`` and
  use it as an answer to where :command:`opam` should be installed.
  

* Install the OCaml compiler

  .. code:: bash

      opam init --disable-sandboxing --comp=4.07.0
      eval `${QP_ROOT}/bin/opam env`

* Install the required external OCaml libraries

  .. code:: bash

      opam install ocamlbuild cryptokit zmq core sexplib ppx_sexp_conv ppx_deriving getopt


EZFIO
-----

*EZFIO* is the Easy Fortran Input/Output library generator.

* Download EZFIO here : `<https://gitlab.com/scemama/EZFIO/-/archive/master/EZFIO-master.tar.gz>`_ and move
  the downloaded archive in the :file:`${QP_ROOT}/external` directory

* Extract the archive, and rename it as :file:`${QP_ROOT}/external/ezfio`


Docopt
------

*Docopt* is a Python package defining a command-line interface description language.

If you have *pip* for Python2, you can do 

.. code:: bash

   pip2 install --user docopt

Otherwise,

* Download the archive here : `<https://github.com/docopt/docopt/releases/tag/0.6.2>`_

* Extract the archive

* Copy :file:`docopt-0.6.2/docopt.py` in the :file:`${QP_ROOT}/scripts` directory