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diff --git a/doc/html/bbv2/tutorial/properties.html b/doc/html/bbv2/tutorial/properties.html new file mode 100644 index 0000000000..560c51adc5 --- /dev/null +++ b/doc/html/bbv2/tutorial/properties.html @@ -0,0 +1,173 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>Properties</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="../tutorial.html" title="Chapter 23. Tutorial"> +<link rel="prev" href="../tutorial.html" title="Chapter 23. Tutorial"> +<link rel="next" href="hierarchy.html" title="Project Hierarchies"> +</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="../tutorial.html"><img src="../../images/prev.png" alt="Prev"></a><a accesskey="u" href="../tutorial.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="hierarchy.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.tutorial.properties"></a>Properties</h2></div></div></div> +<div class="toc"><dl> +<dt><span class="section"><a href="properties.html#bbv2.tutorial.properties.requirements">Build Requests and Target Requirements</a></span></dt> +<dt><span class="section"><a href="properties.html#bbv2.tutorial.properties.project_attributes">Project Attributes</a></span></dt> +</dl></div> +<p> + To portably represent aspects of target configuration such as + debug and release variants, or single- and multi-threaded + builds, Boost.Build uses <em class="firstterm">features</em> with + associated <em class="firstterm">values</em>. For + example, the <code class="computeroutput">debug-symbols</code> feature can have a value of <code class="computeroutput">on</code> or + <code class="computeroutput">off</code>. A <em class="firstterm">property</em> is just a (feature, + value) pair. When a user initiates a build, Boost.Build + automatically translates the requested properties into appropriate + command-line flags for invoking toolset components like compilers + and linkers.</p> +<p>There are many built-in features that can be combined to + produce arbitrary build configurations. The following command + builds the project's <code class="computeroutput">release</code> variant with inlining + disabled and debug symbols enabled: + +</p> +<pre class="screen"> +bjam release inlining=off debug-symbols=on +</pre> +<p>Properties on the command-line are specified with the syntax: + +</p> +<pre class="screen"><em class="replaceable"><code>feature-name</code></em>=<em class="replaceable"><code>feature-value</code></em></pre> +<p>The <code class="option">release</code> and <code class="option">debug</code> that we've seen + in <span><strong class="command">bjam</strong></span> invocations are just a shorthand way to + specify values of the <code class="varname">variant</code> feature. For example, the command + above could also have been written this way: + + </p> +<pre class="screen"> +bjam variant=release inlining=off debug-symbols=on + </pre> +<p><code class="varname">variant</code> is so commonly-used that it has + been given special status as an <em class="firstterm">implicit</em> + feature—Boost.Build will deduce the its identity just + from the name of one of its values. + </p> +<p> + A complete description of features can be found in <a href="../reference/definitions.html#bbv2.reference.features" title="Features and properties">the section called “Features and properties”</a>. + </p> +<div class="section" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="bbv2.tutorial.properties.requirements"></a>Build Requests and Target Requirements</h3></div></div></div> +<p> + The set of properties specified on the command line constitute + a <em class="firstterm">build request</em>—a description of + the desired properties for building the requested targets (or, + if no targets were explicitly requested, the project in the + current directory). The <span class="emphasis"><em>actual</em></span> + properties used for building targets are typically a + combination of the build request and properties derived from + the project's <code class="filename">Jamroot</code> (and its other + Jamfiles, as described in <a href="hierarchy.html" title="Project Hierarchies">the section called “Project Hierarchies”</a>). For example, the + locations of <code class="computeroutput">#include</code>d header files are normally + not specified on the command-line, but described in + Jamfiles as <em class="firstterm">target + requirements</em> and automatically combined with the + build request for those targets. Multithread-enabled + compilation is another example of a typical target + requirement. The Jamfile fragment below + illustrates how these requirements might be specified. + </p> +<pre class="programlisting"> +exe hello + : hello.cpp + : <include>boost <threading>multi + ; +</pre> +<p> + When <code class="filename">hello</code> is built, the two + requirements specified above will always be present. + If the build request given on the <span><strong class="command">bjam</strong></span> + command-line explictly contradicts a target's requirements, + the target requirements usually override (or, in the case of + “free” features like + <code class="varname"><include></code>, + <sup>[<a name="id1701753" href="#ftn.id1701753">4</a>]</sup> + augments) the build request. + + </p> +<div class="tip" style="margin-left: 0.5in; margin-right: 0.5in;"> +<h3 class="title">Tip</h3> +<p>The value of the <code class="varname"><include></code> feature is + relative to the location of <code class="filename">Jamroot</code> where it's + used. + </p> +</div> +</div> +<div class="section" lang="en"> +<div class="titlepage"><div><div><h3 class="title"> +<a name="bbv2.tutorial.properties.project_attributes"></a>Project Attributes</h3></div></div></div> +<p> + If we want the same requirements for our other + target, <code class="filename">hello2</code>, we could simply duplicate + them. However, as projects grow, that approach leads to a great + deal of repeated boilerplate in Jamfiles. + + Fortunately, there's a better way. Each project can specify a + set of <em class="firstterm">attributes</em>, including + requirements: + +</p> +<pre class="programlisting"> +project + : requirements <include>/home/ghost/Work/boost <threading>multi + ; + +exe hello : hello.cpp ; +exe hello2 : hello.cpp ; +</pre> +<p> + + The effect would be as if we specified the same requirement for + both <code class="filename">hello</code> and <code class="filename">hello2</code>. + </p> +</div> +<div class="footnotes"> +<br><hr width="100" align="left"> +<div class="footnote"><p><sup>[<a name="ftn.id1701753" href="#id1701753">4</a>] </sup> +See <a href="../reference/definitions.html#bbv2.reference.features.attributes" title="Feature Attributes">the section called “Feature Attributes”</a></p></div> +</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="../tutorial.html"><img src="../../images/prev.png" alt="Prev"></a><a accesskey="u" href="../tutorial.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="hierarchy.html"><img src="../../images/next.png" alt="Next"></a> +</div> +</body> +</html> |