doc: add doc building/publishing instructions

Add a new document describing how doc building and publishing
works and how to setup a doc working directory and build tools to make
it so.

Signed-off-by: David B. Kinder <david.b.kinder@intel.com>

doc/Makefile

@@ -33,7 +33,7 @@ doxy: pullsource
 	$(Q)(cat acrn.doxyfile) | doxygen -  2>&1
 
 html: doxy
-	$(Q)$(SPHINXBUILD) -b html -d $(BUILDDIR)/doctrees $(SOURCEDIR) $(BUILDDIR)/html $(SPHINXOPTS) $(O) > doc.log 2>&1
+	-$(Q)$(SPHINXBUILD) -b html -d $(BUILDDIR)/doctrees $(SOURCEDIR) $(BUILDDIR)/html $(SPHINXOPTS) $(O) > doc.log 2>&1
 	$(Q)./scripts/filter-doc-log.sh doc.log
 
 

doc/docbuild.rst

@@ -0,0 +1,219 @@
+.. _acrn_doc:
+
+ACRN documentation generation
+#############################
+
+These instructions will walk you through generating the Project ACRN's
+documentation and publishing it to https://projectacrn.github.io.
+You can also use these instructions to generate the ARCN documentation
+on your local system.
+
+Documentation overview
+**********************
+
+Project ACRN content is written using the reStructuredText markup
+language (.rst file extension) with Sphinx extensions, and processed
+using Sphinx to create a formatted stand-alone website. Developers can
+view this content either in its raw form as .rst markup files, or you
+can generate the HTML content and view it with a web browser directly on
+your workstation.
+
+You can read details about `reStructuredText`_, and `Sphinx`_ from
+their respective websites.
+
+The project's documentation contains the following items:
+
+* ReStructuredText source files used to generate documentation found at the
+  http://projectacrn.github.io website. All of the reStructuredText sources
+  are found in this acrn-documentation repo.
+
+* Doxygen-generated material used to create all API-specific documents
+  found at http://projectacrn.github.io/api/.  Clones of the
+  acrn-hypervisor and acrn-devicemodel repos are also used to access the
+  header files for the the public APIs, but more about that later.
+
+The reStructuredText files are processed by the Sphinx documentation system,
+and make use of the breathe extension for including the doxygen-generated API
+material.
+
+
+Set up the documentation working folders
+****************************************
+
+You'll need git installed to get the working folders set up:
+
+* For an Ubuntu development system use:
+
+  .. code-block:: bash
+
+     sudo apt-get install git
+
+* For a Fedora development system use
+
+  .. code-block:: bash
+
+     sudo dnf install git
+
+Because we need up-to-date header files to generate API docs, doc
+generation assumes the three repos are cloned as sibling folders.
+Here's the recommended folder setup for documentation contributions and
+generation:
+
+.. code-block: none
+
+   projectacrn/
+      acrn-documentation/
+      acrn-hypervisor/
+      acrn-devicemodel/
+
+It's best if these folders are ssh clones of your personal forks of the
+upstream project ACRN repos (though https clones work too):
+
+#. Use your browser to visit https://github.com/projectacrn.  One at a
+   time, visit the **acrn-documentation**, **acrn-hypervisor**, and
+   **acrn-devicemodel** repos and do a fork to your personal GitHub account.
+
+   .. image:: images/acrn-doc-fork.png
+      :align: center
+
+#. At a command prompt, create the working folder and clone the three
+   repositories to your local computer:
+
+   .. code-block:: bash
+
+      cd ~
+      mkdir projectacrn && cd projectacrn
+      git clone  git@github.com:<github-username>/acrn-documentation.git
+      git clone  git@github.com:<github-username>/acrn-hypervisor.git
+      git clone  git@github.com:<github-username>/acrn-devicemodel.git
+
+#. For each of the cloned local repos, tell git about the upstream repos:
+
+   .. code-block:: bash
+
+      cd acrn-documentation
+      git remote add upstream git@github.com:projectacrn/acrn-documentation.git
+      cd ../acrn-hypervisor
+      git remote add upstream git@github.com:projectacrn/acrn-hypervisor.git
+      cd ../acrn-devicemodel
+      git remote add upstream git@github.com:projectacrn/acrn-devicemodel.git
+      cd ..
+
+#. If you haven't do so already, be sure to configure git with your name
+   and email address for the signed-off-by line in your commit messages:
+
+   .. code-block:: bash
+
+      git config --global user.name "David Developer"
+      git config --global user.email "david.developer@company.com"
+
+Installing the documentation tools
+**********************************
+
+Our documentation processing has been tested to run with:
+
+* Python 3.6.3
+* Doxygen version 1.8.13
+* Sphinx version 1.6.7
+* Breathe version 4.7.3
+* docutils version 0.14
+* sphinx_rtd_theme version 0.2.4
+
+Depending on your Linux version, install the needed tools:
+
+* For Ubuntu use:
+
+  .. code-block:: bash
+
+     sudo apt-get install doxygen python3-pip python3-wheel make
+
+* For Fedora use:
+
+  .. code-block:: bash
+
+     sudo dnf install doxygen python3-pip python3-wheel make
+
+And for either Linux environment, install the remaining python-based
+tools:
+
+  .. code-block:: bash
+
+     cd ~/projectacrn/acrn-documentation
+     pip3 install --user -r scripts/requirements.txt
+
+And with that you're ready to generate the documentation.
+
+Documentation presentation theme
+********************************
+
+Sphinx supports easy customization of the generated documentation
+appearance through the use of themes.  Replace the theme files and do
+another ``make htmldocs`` and the output layout and style is changed.
+The ``read-the-docs`` theme is installed as part of the
+``requirements.txt`` list above.
+
+Running the documentation processors
+************************************
+
+The acrn-documentation directory has all the .rst source files, extra tools, and Makefile for
+generating a local copy of the ACRN technical documentation.
+
+.. code-block:: bash
+
+   cd ~/projectacrn/acrn-documentation
+   make html
+
+Depending on your development system, it will take about 15 seconds to
+collect and generate the HTML content.  When done, you can view the HTML
+output with your browser started at ``~/projectacrn/acrn-documentation/_build/html/index.html``
+
+Publishing content
+******************
+
+If you have push rights to the projectacrn repo called
+projectacrn.github.io, you can update the public project documentation
+found at https://projectacrn.github.io.
+
+You'll need to do a one-time clone the upstream repo:
+
+.. code-block:: bash
+
+   git clone git@github.com:projectacrn/projectacrn.github.io.git
+
+Then, after you've verified the generated HTML from ``make html`` looks
+good, you can push directly to the publishing site with:
+
+.. code-block:: bash
+
+   make publish
+
+This will delete everything in the publishing repo (in case the new version has
+deleted files) and push a copy of the newly-generated HTML content
+directly to the GitHub pages publishing repo.  The public site at
+https://projectacrn.github.io will be updated (nearly) immediately
+so it's best to verify the locally generated html before publishing.
+
+Filtering expected warnings
+***************************
+
+Alas, there are some known issues with the doxygen/Sphinx/Breathe
+processing that generates warnings for some constructs, in particular
+around unnamed structures in nested unions or structs.
+While these issues are being considered for fixing in
+Sphinx/Breathe, we've added a post-processing filter on the output of
+the documentation build process to check for "expected" messages from the
+generation process output.
+
+The output from the Sphinx build is processed by the python script
+``scripts/filter-known-issues.py`` together with a set of filter
+configuration files in the ``.known-issues/doc`` folder.  (This
+filtering is done as part of the ``Makefile``.)
+
+If you're contributing components included in the ACRN API
+documentation and run across these warnings, you can include filtering
+them out as "expected" warnings by adding a conf file to the
+``.known-issues/doc`` folder, following the example of other conf files
+found there.
+
+.. _reStructuredText: http://sphinx-doc.org/rest.html
+.. _Sphinx: http://sphinx-doc.org/

doc/index.rst

@@ -31,6 +31,7 @@ Sections
    release_notes.rst
    contribute.rst
    api/index.rst
+   docbuild.rst
 
 Indices and Tables
 ******************

doc/scripts/requirements.txt

@@ -1,4 +1,4 @@
 breathe==4.7.3
-sphinx==1.6.5
+sphinx==1.6.7
 docutils==0.14
 sphinx_rtd_theme