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diff --git a/doc/html/bbv2/extending/targets.html b/doc/html/bbv2/extending/targets.html new file mode 100644 index 0000000000..18a6b06736 --- /dev/null +++ b/doc/html/bbv2/extending/targets.html @@ -0,0 +1,148 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>Target types</title> +<link rel="stylesheet" href="../../boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.68.1"> +<style type="text/css"> +body { background-image: url('http://docbook.sourceforge.net/release/images/draft.png'); + background-repeat: no-repeat; + background-position: top left; + /* The following properties make the watermark "fixed" on the page. */ + /* I think that's just a bit too distracting for the reader... */ + /* background-attachment: fixed; */ + /* background-position: center center; */ + }</style> +<link rel="start" href="../../index.html" title="The Boost C++ Libraries"> +<link rel="up" href="../extender.html" title="Chapter 25. Extender Manual"> +<link rel="prev" href="../extender.html" title="Chapter 25. Extender Manual"> +<link rel="next" href="tools.html" title="Tools and generators"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<table cellpadding="2" width="100%"> +<td valign="top"><img alt="boost.png (6897 bytes)" width="277" height="86" src="../../../../boost.png"></td> +<td align="center"><a href="../../../../index.htm">Home</a></td> +<td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td> +<td align="center"><a href="../../../../people/people.htm">People</a></td> +<td align="center"><a href="../../../../more/faq.htm">FAQ</a></td> +<td align="center"><a href="../../../../more/index.htm">More</a></td> +</table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../extender.html"><img src="../../images/prev.png" alt="Prev"></a><a accesskey="u" href="../extender.html"><img src="../../images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../images/home.png" alt="Home"></a><a accesskey="n" href="tools.html"><img src="../../images/next.png" alt="Next"></a> +</div> +<div class="section" lang="en"> +<div class="titlepage"><div><div><h2 class="title" style="clear: both"> +<a name="bbv2.extending.targets"></a>Target types</h2></div></div></div> +<div class="toc"><dl><dt><span class="section"><a href="targets.html#bbv2.extending.scanners">Scanners</a></span></dt></dl></div> +<p>The first thing we did in the <a href="../extender.html#bbv2.extender.intro" title="Introduction">intruduction</a> was declaring a + new target type: +</p> +<pre class="programlisting"> +import type ; +type.register VERBATIM : verbatim ; +</pre> +<p> + The type is the most important property of a target. Boost.Build can + automatically generate necessary build actions only because you + specify the desired type (using the different main target rules), and + because Boost.Build can guess the type of sources from their + extensions. + </p> +<p>The first two parameters for the <code class="computeroutput">type.register</code> rule + are the name of new type and the list of extensions associated with + it. A file with an extension from the list will have the given target + type. In the case where a target of the declared type is generated + from other sources, the first specified extension will be used. + </p> +<p>Sometimes you want to change the suffix used for generated targets + depending on build properties, such as toolset. For example, some compiler + uses extension <code class="literal">elf</code> for executable files. You can use the + <code class="computeroutput">type.set-generated-target-suffix</code> rule: +</p> +<pre class="programlisting"> +type.set-generated-target-suffix EXE : <toolset>elf : elf ; +</pre> +<p>A new target type can be inherited from an existing one. +</p> +<pre class="programlisting"> +type.register PLUGIN : : SHARED_LIB ; +</pre> +<p> + The above code defines a new type derived from + <code class="computeroutput">SHARED_LIB</code>. Initially, the new type inherits all the + properties of the base type - in particular generators and suffix. + Typically, you'll change the new type in some way. For example, using + <code class="computeroutput">type.set-generated-target-suffix</code> you can set the suffix for + the new type. Or you can write special generator for the new type. For + example, it can generate additional metainformation for plugin. + In either way, the <code class="computeroutput">PLUGIN</code> type can be used whenever + <code class="computeroutput">SHARED_LIB</code> can. For example, you can directly link plugins + to an application. + </p> +<p>A type can be defined as "main", in which case Boost.Build will + automatically declare a main target rule for building targets of that + type. More details can be found <a href="rules.html#bbv2.extending.rules.main-type">later</a>. + </p> +<div class="section" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="bbv2.extending.scanners"></a>Scanners</h3></div></div></div> +<p> + Sometimes, a file can refer to other files via some include + mechanism. To make Boost.Build track dependencies to the included + files, you need to provide a scanner. The primary limitation is that + only one scanner can be assigned to a target type. + </p> +<p>First, we need to declare a new class for the scanner: +</p> +<pre class="programlisting"> +class verbatim-scanner : common-scanner +{ + rule pattern ( ) + { + return "//###include[ ]*\"([^\"]*)\"" ; + } +} +</pre> +<p> + All the complex logic is in the <code class="computeroutput">common-scanner</code> + class, and you only need to override the method that returns + the regular expression to be used for scanning. The + paranthethis in the regular expression indicate which part + of the string is the name of the included file. Only the + first parenthesized group in the regular expression will be + recognized; if you can't express everything you want that + way, you can return multiple regular expressions, each of + which contains a parenthesized group to be matched. + </p> +<p>After that, we need to register our scanner class: +</p> +<pre class="programlisting"> +scanner.register verbatim-scanner : include ; +</pre> +<p> + The value of the second parameter, in this case + <code class="computeroutput">include</code>, specifies the properties that contain the list + of paths that should be searched for the included files. + </p> +<p>Finally, we assign the new scaner to the <code class="computeroutput">VERBATIM</code> + target type: +</p> +<pre class="programlisting"> +type.set-scanner VERBATIM : verbatim-scanner ; +</pre> +<p> + That's enough for scanning include dependencies. + </p> +</div> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><small></small></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="../extender.html"><img src="../../images/prev.png" alt="Prev"></a><a accesskey="u" href="../extender.html"><img src="../../images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../images/home.png" alt="Home"></a><a accesskey="n" href="tools.html"><img src="../../images/next.png" alt="Next"></a> +</div> +</body> +</html> |