.. _qibuild-managing-deps:

Managing dependencies between projects
======================================

In this tutorial, you will learn how to manage dependencies between projects.

Requirements
------------

We will assume you have a properly configured qiBuild
worktree, and that you have managed to compile a basic project.

Please make sure you have follow the :ref:`getting started tutorial <qibuild-getting-started>`

Overview
--------

We are going to create two separate projects: ``hello`` and ``world,`` where ``hello``
depends on the compiled library found in ``world.``

The ``world`` project contains sources to build a dynamic library (``libworld.so`` or
``world.dll``)

The ``hello`` project contains source to build an executable named ``hello`` which
depends on the ``world`` library.

It also contains a small test that simply tries to launch ``hello.``

.. FIXME!
   The sources of this example can be found ...

Extract the archive in your qiBuild worktree, you should end up with something
looking like::

  .qi
  |__ build.cfg
  world
  |__ CMakeLists.txt
  |__ qibuild.cmake
  |__ qibuild.manifest
  |__ world
      |__ world.h
      |__ world.cpp
  hello
  |__ CMakeLists.txt
  |__ qibuild.cmake
  |__ qibuild.manifest
  |__ main.cpp



qiBuild in action
------------------

Configuring and building the hello project is as easy as

.. code-block:: console

  $ qibuild configure hello
  $ qibuild make hello
  $ qibuild test hello


For this to work, you only have to write two ``qibuild.manifest`` files

The first one in ``QI_WORK_TREE/world/qibild.manifest`` simply tells
qibuild that there is a project named ``world`` in
``QI_WORK_TREE/world``

.. code-block:: ini

   [project world]


The second one in ``QI_WORK_TREE/hello`` tells ``qibuild``
there is a project name ``hello`` in ``QI_WORK_TREE/hello``,
and that it depends on the ``world`` project:

.. code-block:: ini

   [project hello]
   depends = world

You can see that configuring ``hello`` caused the ``world`` project to be configured
too, and that building ``hello`` also built the ``world`` project.

On Windows, the ``world`` DLL was copied right next to ``hello.exe,`` so running
``qibuild test hello`` just worked.

If you are using Visual Studio, you can open ``hello.sln`` in
QI_WORK_TREE/hello/build-.../hello.sln, select "hello" as startup project, and
start debugging hello_d.exe right away.

.. warning:: If you try to compile hello in release, you’ll get an
  error because "world" has not been compiled in release, so world.lib could
  not found.

Simply run

.. code-block:: console

  $ qibuild configure --release world
  $ qibuild make --release world

And try again.