watchrobot/modules/waf/docs/slides/presentation/slides.tex

% © Jérôme Carretero 2010 (Zougloub)
% See license at end of file

\documentclass[xetex]{beamer}
\RequirePackage{fontspec}
\RequirePackage{xunicode} %Unicode extras!
\RequirePackage{xltxtra}  %Fixes
\RequirePackage{verbatim}
\RequirePackage{listings}
\RequirePackage{multicol}
\RequirePackage{moreverb}

\usetheme[hideothersubsections, width=.15\textwidth]{waf}
\usecolortheme{orchid}
\setbeamertemplate{navigation symbols}{} % hides navigation symbols

\usepackage{fancybox}
\usepackage{multimedia}

\usepackage{eso-pic}

\title[Build Tools]{
	Build Automation Tools
}

\subtitle{
	Comparison of make and waf for non-technical users
}
 
\author[]{Jérôme Carretero}
 
\institute[] {}

\date{2010-11-05}

\lstdefinelanguage{waf}
  {morekeywords={def, ctx, bld, opt, configure, options, build, features, source, target, load, use},
	  sensitive=true,
	  morecomment=[l]{\#},
	  %morecomment=[s]{/*}{*/},
	  morestring=[b]",
}
\begin{document}

\lstset{
 language=make,
 basicstyle=\tiny,%\footnotesize,
 %numbers=left,% -> where to put the line-numbers
 %numberstyle=\footnotesize,% -> size of the fonts used for the line-numbers
 %stepnumber=5,% -> the step between two line-numbers.
 %numbersep=5pt,% -> how far the line-numbers are from the code
 %backgroundcolor=\color{white},% -> sets background color (needs package)
 showspaces=false,% -> show spaces adding particular underscores
 showstringspaces=false,% -> underline spaces within strings
 showtabs=false,% -> show tabs within strings through particular underscores
 frame=single,% -> adds a frame around the code
 tabsize=4,% -> sets default tab-size to 2 spaces
 captionpos=b,% -> sets the caption-position to bottom
 breaklines=true,% -> sets automatic line breaking
 breakatwhitespace=false,% -> automatic breaks happen at whitespace
 %morecomment=[l]{//},
}

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    	\begin{picture}(320, 270)
		\put(300, 250){\includegraphics[width=.05\textwidth]{gfx/waflogo.png}}
	\end{picture}
}


\frame{
    	\begin{picture}(0,0)
		%\put(0,-5){\includegraphics[width=.2\textwidth]{RT09_Logo.jpg}}
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	\vspace{1cm}
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\frame{
\frametitle{Outline}
	\tableofcontents[subsectionstyle=hide/show/hide]
}

\section{Introduction}

\begin{frame}{Definition and Context}
	\begin{itemize}
		\item Build automation is the act of scripting or automating a wide variety of tasks that software developers do in their day-to-day activities \cite{wp_build_automation}.
		\item I have seen a lot of code and used many build automation tools
		\item For technical reasons, I consider waf to be the best tool out there
	\end{itemize}
\end{frame}

\section{Make}


\frame{
\frametitle{Make: outline}
	\tableofcontents[sectionstyle=hide/hide,subsectionstyle=hide/show/hide]
}

\begin{frame}[fragile]
	\scriptsize
	\frametitle{Simplest Makefile}
	\lstinputlisting{snippets/make-1/Makefile}
	\lstinputlisting{snippets/make-1/output}
\end{frame}

\subsection{Structure of a Makefile}

\begin{frame}[fragile]{Makefile properties}
	Makefiles are like basic kitchen recipes:
	\begin{itemize}
		\item basic syntax:\\
		\begin{lstlisting}
			variable = value
		
			target: dependencies
			    commands to run
		\end{lstlisting}
		\item plus include ability and a few commands
	\end{itemize}

	Features:
	\begin{itemize}
		\item the return codes of the commands are checked for errors
		\item the variables are expanded into commands, dependencies, or command strings
		\item pretty simple, but relatively efficient
		\item nothing beats make for tiny jobs
	\end{itemize}
\end{frame}



\subsection{Limitations}

\begin{frame}{It can become complicated}
	The following is a little caricature of what becomes necessary with big projects.\\
	It only works with gcc-style compilers on UNIX:
	\lstinputlisting{snippets/make-2/Makefile}
	\lstinputlisting{snippets/make-2/output}
\end{frame}

\subsection{Conclusion}

\begin{frame}{So what}
	\begin{itemize}
		\item make was born in 1973\\
		It's mature, but not very high-tech
		\item very efficient for small 80's projects
		\item since then, other tools have appeared
		\item domain-specific language
		\item string-based, command-line based (based on the usage of shell scripts)
	\end{itemize}
\end{frame}

\section{Waf Intro}

\frame{
\frametitle{Waf: outline}
	\tableofcontents[sectionstyle=hide/hide,subsectionstyle=hide/show/hide]
}

\subsection{Waf is to Make as C++ is to assembly}


\begin{frame}{Intro}
	\begin{itemize}
		\item waf is a newest-generation build tool\\
		History: sh $\to$ make $\to$ scons $\to$ waf
		\item built on the Python language, not a custom, restricted special-purpose one\\
		$\neq$ CMake, ant, maven\\
		a waf script can do \textbf{anything}
		\item task-based, not file-based\\
		can build abstract stuff
		\item includes build configuration
		\item custom commands can be added
		\item tool abstraction, more portability, cross-compilation friendly
	\end{itemize}
\end{frame}


\begin{frame}[fragile]{Simplest waf script}
	\scriptsize
	\lstinputlisting[language=waf]{snippets/waf-1/wscript}
	\lstinputlisting{snippets/waf-1/output}
\end{frame}

\subsection{New Concepts}

\begin{frame}{New Concepts}
	\begin{itemize}
		\item \texttt{configure()} configures the build machine to enable proper compilation (library detection, config.h writing, etc.).\\
		Similar to autoconf.\\
		Useful to provide better portability of code.
		
		\item \texttt{build()} is where you define your build tasks

		\item \texttt{options()} allows to provide compilation options to the build\\
		Mostly unused in simple cases
	\end{itemize}
\end{frame}

\begin{frame}[fragile]{Dependencies Graph}
	If you wanted to export modules A and/or B:
	\lstinputlisting[language=waf]{snippets/waf-2/wscript}
\end{frame}


\begin{frame}{Dependencies Specifications}
	\begin{center}
		\includegraphics[height=.3\textheight]{gfx/slides-executable_deps.png}
	\end{center}
	\begin{itemize}
		\item You don't need to specify the whole dependency tree of your target\\
		just the closest nodes ! $\neq$ make
		\item every \textit{task generator} defines what it does and what it uses
		\item[+] less redundancy
		\item[+] build scripts quickly become much smaller and powerful than equivalent makefiles
	\end{itemize}
\end{frame}


\begin{frame}{Tools}
	\begin{itemize}
		\item You can use waf just like make (specify everything) but there are \textit{tools}
		\item ex: compiler\_c, compiler\_cxx, java, cs, winres, d, bison, qt4, ...
		\item[+] The tools avoid you to type and build scripts are more readable
		\item[+] compiler\_c automatically detects MSVC, GCC, ICC, SUNCC, ...
		\item[+] Less lines of code, less maintenance
	\end{itemize}
\end{frame}

\begin{frame}{Waf “Recursivity”}
	\begin{itemize}
		\item Variables do not get shared with recursive make
		\item They do with recursive waf scripts
	\end{itemize}

	You define a component in a module, and use it in another module “as is”.
	\\
	Ex: NGPF build scripts, the targets are shared between folders

\end{frame}


\begin{frame}{Dependencies Scanning}
	\begin{itemize}
		\item waf tools automatically scan include dependencies (C, C++, LaTeX, Java, C\#), ...
		\item waf keeps a cache of the task yields checksums
		\item[$\to$] waf will only rebuild modified files
		\item[$\to$] faster online compilation (a lot less \texttt{make clean} performed)
	\end{itemize}
\end{frame}


\begin{frame}{More}
	\begin{itemize}
		\item built-in support for build folders\\
		\textbf{very important}
		\item built-in support for unit testing
		\item built-in support for build machines (auto-build)
		\item built-in support for build variants and cross-compilation
	\end{itemize}
\end{frame}

\subsection{Myth Busting}

\begin{frame}{“waf is a big pile of dark crap”}
	Wrong:
	\begin{itemize}
		\item waf is very small!\\
		core files are <6500 lines of Python code including comments (25\%)\\
		GNU make: 32000 (C)
		\item logical and extensible architecture
		\begin{itemize}
			\scriptsize
			\item Core: Context, Build, Node, Configure, Task, TaskGen, Runner, misc %(Errors, Utils, ConfigSet)
			\item Plugins: Tools/
		\end{itemize}
		\item lots and lots of documentation and examples, great support
		\item used by lots of high-tech people:
		\begin{itemize}
			\scriptsize
			\item big enterprise projects (Cisco® IOS, ...)
			\item big OpenSource projects (Samba \cite{samba_waf}, XMMS2, Ardour \cite{ardour_waf}, Jack, ...)
			\item big research projects (NS-3, ...)
		\end{itemize}
	\end{itemize}
\end{frame}


\begin{frame}{“waf is too complex for me”}
	waf scripts are easy to read and write.
	A wscript is typically composed of:
	\begin{itemize}
		\item \texttt{configure()}
		\begin{itemize}
			\scriptsize
			\item external libraries definitions for multiple build platforms (eg. Linux 32+64, QNX, Win32 cross, Win32 native)
			\item targets configuration
			\item environment checks
			\item config.h writing
		\end{itemize}
		\item \texttt{build()}: build rules (the most touched and simplest part)
		\item misc (optional): multi-variant build functions, command-line options parsing, etc.
	\end{itemize}
	
	It's easy to create a simple wscript (lots of examples, very simple syntax).
	\\
	~\\
	Contributing to a big wscript is easier than contributing to a big Makefile.
	\\
	The only important part when contributing is the definition of the build task generators.
\end{frame}


\begin{frame}{Summary}
	\begin{itemize}
		\item a recent tool (2005)\\
		still, a lot of examples, and support for complex usages are available
		\item a little more complex than make for tiny projects\\
		but it's worth it for everyday development
		\item more performant
		\item a lot more powerful and flexible
		\item me likes it
	\end{itemize}
\end{frame}

\section{Conclusion}

\begin{frame}{Conclusion}
	\begin{itemize}
		\item I am convinced that waf brings long-term advantages\\
		I definitely recommend it for complex builds
		\item very appropriate for modular project integration
		\item I would not maintain huge unreadable makefiles
	\end{itemize}
\end{frame}

\begin{frame}{Links}

\begin{thebibliography}{9}

\bibitem{samba_waf} Samba team waf page\\
\url{http://wiki.samba.org/index.php/Waf}

\bibitem{wp_build_automation} Wikipedia article on Build Automation\\
\url{http://en.wikipedia.org/wiki/Build_automation}

\bibitem{ardour_waf} Ardour build page\\
\url{http://www.ardour.org/building_ardour3}

\bibitem{xmms2_waf} XMMS2 installation instructions\\
\url{http://xmms2.org/wiki/Install_instructions}

\end{thebibliography}

\end{frame}

\end{document}

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