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diff --git a/libs/predef/doc/html/predef/check_utilities.html b/libs/predef/doc/html/predef/check_utilities.html new file mode 100644 index 000000000..1664b197d --- /dev/null +++ b/libs/predef/doc/html/predef/check_utilities.html @@ -0,0 +1,148 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Check Utilities</title> +<link rel="stylesheet" href="../boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> +<link rel="home" href="../index.html" title="Predef 1.2"> +<link rel="up" href="../index.html" title="Predef 1.2"> +<link rel="prev" href="reference/version_definition_macros.html" title="Version definition macros"> +<link rel="next" href="history.html" title="History"> +</head> +<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> +<div class="spirit-nav"> +<a accesskey="p" href="reference/version_definition_macros.html"><img src="../images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.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="history.html"><img src="../images/next.png" alt="Next"></a> +</div> +<div class="section"> +<div class="titlepage"><div><div><h2 class="title" style="clear: both"> +<a name="predef.check_utilities"></a><a class="link" href="check_utilities.html" title="Check Utilities">Check Utilities</a> +</h2></div></div></div> +<p> + The <code class="computeroutput"><span class="identifier">predef_check</span></code> utility provides + a facility for building a program that will check a given set of expressions + against the definitions it detected when it was built. + </p> +<h4> +<a name="predef.check_utilities.h0"></a> + <span class="phrase"><a name="predef.check_utilities.predef_check_programs"></a></span><a class="link" href="check_utilities.html#predef.check_utilities.predef_check_programs"><code class="literal">predef_check</code> + programs</a> + </h4> +<p> + Even though there is only one <code class="computeroutput"><span class="identifier">predef_check</span></code> + program, there are variations for each of the languages that are detected by + Predef to match the convention for sources files. For all of them one invokes + with a list of expression arguments. The expressions are evaluated within the + context of the particular <code class="literal">predef_check</code> program and if they + all are true zero (0) is returned. Otherwise the index of the first false expression + is returned. + </p> +<p> + The expression syntax is simple: + </p> +<pre class="programlisting">predef-definition [ relational-operator version-value ] +</pre> +<p> + <em class="replaceable"><code>predef-definition</code></em> can be any of the Predef definitions. + For example <code class="computeroutput"><span class="identifier">BOOST_COMP_GCC</span></code>. + </p> +<p> + <em class="replaceable"><code>relational-operator</code></em> can be any of: <code class="literal">></code>, + <code class="literal"><</code>, <code class="literal">>=</code>, <code class="literal"><=</code>, + <code class="literal">==</code> and <code class="literal">!=</code>. + </p> +<p> + <em class="replaceable"><code>version-number</code></em> can be a full or partial version + triplet value. If it's a partial version triple it is completed with zeros. + That is <code class="literal">x.y</code> is equivalent to <code class="literal">x.y.0</code> and + <code class="literal">x</code> is equivalent to <code class="literal">x.0.0</code>. + </p> +<p> + The <em class="replaceable"><code>relations-operator</code></em> and <em class="replaceable"><code>version-number</code></em> + can be ommited. In which case it is equivalent to: + </p> +<pre class="programlisting">predef-definition > 0.0.0 +</pre> +<h4> +<a name="predef.check_utilities.h1"></a> + <span class="phrase"><a name="predef.check_utilities.using_with_boost_build"></a></span><a class="link" href="check_utilities.html#predef.check_utilities.using_with_boost_build">Using + with Boost.Build</a> + </h4> +<p> + You can use the <code class="literal">predef_check</code> programs directly from Boost + Build to configure target requirements. This is useful for controlling what + gets built as part of your project based on the detailed version information + available in Predef. The basic use is simple: + </p> +<pre class="programlisting">import path-to-predef-src/check/predef + : check require + : predef-check predef-require ; + +exe my_windows_program : windows_source.cpp + : [ predef-require "BOOST_OS_WINDOWS" ] ; +</pre> +<p> + That simple use case will skip building the <code class="literal">my_windows_program</code> + unless one is building for Windows. Like the direct <code class="literal">predef_check</code> + you can pass mutiple expressions using relational comparisons. For example: + </p> +<pre class="programlisting">import path-to-predef-src/check/predef + : check require + : predef-check predef-require ; + +lib my_special_lib : source.cpp + : [ predef-require "BOOST_OS_WINDOWS != 0" "BOOST_OS_VMS != 0"] ; +</pre> +<p> + And in that case the <code class="literal">my_special_lib</code> is built only when the + OS is not Windows or VMS. The <code class="literal">requires</code> rule is a special + case of the <code class="literal">check</code> rule. And is defined in terms of it: + </p> +<pre class="programlisting">rule require ( expressions + : language ? ) +{ + return [ check $(expressions) : $(language) : : <build>no ] ; +} +</pre> +<p> + You can use the <code class="literal">check</code> rule for more control and to implement + something other than control of what gets built. The definition for the <code class="literal">check</code> + rule is: + </p> +<pre class="programlisting">rule check ( expressions + : language ? : true-properties * : false-properties * ) +</pre> +<p> + When invoked as a reuirement of a Boost Build target this rule will add the + <code class="literal">true-properties</code> to the target if all the <code class="literal">expressions</code> + evaluate to true. Otherwise the <code class="literal">false-properties</code> get added + as requirements. For example you could use it to enable or disable features + in your programs: + </p> +<pre class="programlisting">import path-to-predef-src/check/predef + : check require + : predef-check predef-require ; + +exe my_special_exe : source.cpp + : [ predef-check "BOOST_OS_WINDOWS == 0" + : <define>ENABLE_WMF=0 + : <define>ENABLE_WMF=1 ] ; +</pre> +<p> + For both <code class="literal">check</code> and <code class="literal">require</code> the <code class="literal">language</code> + argument controls which variant of the <code class="literal">predef_check</code> program + is used to check the expressions. It defaults to "c++", but can be + any of: "c", "cpp", "objc", and "objcpp". + </p> +</div> +<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> +<td align="left"></td> +<td align="right"><div class="copyright-footer">Copyright © 2005, 2008-2014 Rene Rivera<p> + Distributed under the Boost Software License, Version 1.0. (See accompanying + file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) + </p> +</div></td> +</tr></table> +<hr> +<div class="spirit-nav"> +<a accesskey="p" href="reference/version_definition_macros.html"><img src="../images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.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="history.html"><img src="../images/next.png" alt="Next"></a> +</div> +</body> +</html> |