toolchain/cmake-3.27.9-linux-x86_64/doc/cmake/html/module/CMakeFindDependencyMacro.html

<!DOCTYPE html>

<html lang="en">
  <head>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" /><meta name="generator" content="Docutils 0.19: https://docutils.sourceforge.io/" />

  <title>CMakeFindDependencyMacro &mdash; CMake 3.27.9 Documentation</title>

    <link rel="stylesheet" type="text/css" href="../_static/pygments.css" />
    <link rel="stylesheet" type="text/css" href="../_static/cmake.css" />
    
    <script data-url_root="../" id="documentation_options" src="../_static/documentation_options.js"></script>
    <script src="../_static/jquery.js"></script>
    <script src="../_static/underscore.js"></script>
    <script src="../_static/_sphinx_javascript_frameworks_compat.js"></script>
    <script src="../_static/doctools.js"></script>
    <script src="../_static/sphinx_highlight.js"></script>
    
    <link rel="shortcut icon" href="../_static/cmake-favicon.ico"/>
    <link rel="index" title="Index" href="../genindex.html" />
    <link rel="search" title="Search" href="../search.html" />
    <link rel="next" title="CMakeFindFrameworks" href="CMakeFindFrameworks.html" />
    <link rel="prev" title="CMakeDependentOption" href="CMakeDependentOption.html" />
 

  </head><body>

    <div class="related" role="navigation" aria-label="related navigation">
      <h3>Navigation</h3>
      <ul>
        <li class="right" style="margin-right: 10px">
          <a href="../genindex.html" title="General Index"
             accesskey="I">index</a></li>
        <li class="right" >
          <a href="CMakeFindFrameworks.html" title="CMakeFindFrameworks"
             accesskey="N">next</a> |</li>
        <li class="right" >
          <a href="CMakeDependentOption.html" title="CMakeDependentOption"
             accesskey="P">previous</a> |</li>
  <li>
    <img src="../_static/cmake-logo-16.png" alt=""
         style="vertical-align: middle; margin-top: -2px" />
  </li>
  <li>
    <a href="https://cmake.org/">CMake</a> &#187;
  </li>
  <li>
    <a href="../index.html">3.27.9 Documentation</a> &#187;
  </li>

          <li class="nav-item nav-item-1"><a href="../manual/cmake-modules.7.html" accesskey="U">cmake-modules(7)</a> &#187;</li>
        <li class="nav-item nav-item-this"><a href="">CMakeFindDependencyMacro</a></li> 
      </ul>
    </div>  

    <div class="document">
      <div class="documentwrapper">
        <div class="bodywrapper">
          <div class="body" role="main">
            
  <section id="cmakefinddependencymacro">
<span id="module:CMakeFindDependencyMacro"></span><h1>CMakeFindDependencyMacro<a class="headerlink" href="#cmakefinddependencymacro" title="Permalink to this heading">¶</a></h1>
<dl class="cmake command">
<dt class="sig sig-object cmake" id="command:find_dependency">
<span class="sig-name descname"><span class="pre">find_dependency</span></span><a class="headerlink" href="#command:find_dependency" title="Permalink to this definition">¶</a></dt>
<dd><p>The <code class="docutils literal notranslate"><span class="pre">find_dependency()</span></code> macro wraps a <span class="target" id="index-0-command:find_package"></span><a class="reference internal" href="../command/find_package.html#command:find_package" title="find_package"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">find_package()</span></code></a> call for
a package dependency:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>find_dependency(&lt;dep&gt; [...])
</pre></div>
</div>
<p>It is designed to be used in a
<a class="reference internal" href="../manual/cmake-packages.7.html#config-file-packages"><span class="std std-ref">Package Configuration File</span></a>
(<code class="docutils literal notranslate"><span class="pre">&lt;PackageName&gt;Config.cmake</span></code>).  <code class="docutils literal notranslate"><span class="pre">find_dependency</span></code> forwards the correct
parameters for <code class="docutils literal notranslate"><span class="pre">QUIET</span></code> and <code class="docutils literal notranslate"><span class="pre">REQUIRED</span></code> which were passed to
the original <span class="target" id="index-1-command:find_package"></span><a class="reference internal" href="../command/find_package.html#command:find_package" title="find_package"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">find_package()</span></code></a> call.  Any additional arguments
specified are forwarded to <span class="target" id="index-2-command:find_package"></span><a class="reference internal" href="../command/find_package.html#command:find_package" title="find_package"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">find_package()</span></code></a>.</p>
<p>If the dependency could not be found it sets an informative diagnostic
message and calls <span class="target" id="index-0-command:return"></span><a class="reference internal" href="../command/return.html#command:return" title="return"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">return()</span></code></a> to end processing of the calling
package configuration file and return to the <span class="target" id="index-3-command:find_package"></span><a class="reference internal" href="../command/find_package.html#command:find_package" title="find_package"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">find_package()</span></code></a>
command that loaded it.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>The call to <span class="target" id="index-1-command:return"></span><a class="reference internal" href="../command/return.html#command:return" title="return"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">return()</span></code></a> makes this macro unsuitable to call
from <a class="reference internal" href="../manual/cmake-developer.7.html#find-modules"><span class="std std-ref">Find Modules</span></a>.</p>
</div>
</dd></dl>

<section id="package-dependency-search-optimizations">
<h2>Package Dependency Search Optimizations<a class="headerlink" href="#package-dependency-search-optimizations" title="Permalink to this heading">¶</a></h2>
<p>If <code class="docutils literal notranslate"><span class="pre">find_dependency</span></code> is called with arguments identical to a previous
call in the same directory, perhaps due to diamond-shaped package
dependencies, the underlying call to <span class="target" id="index-4-command:find_package"></span><a class="reference internal" href="../command/find_package.html#command:find_package" title="find_package"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">find_package()</span></code></a> is optimized
out.  This optimization is important to support large package dependency
graphs while avoiding a combinatorial explosion of repeated searches.
However, the heuristic cannot account for ambient variables that
affect package behavior, such as <code class="docutils literal notranslate"><span class="pre">&lt;PackageName&gt;_USE_STATIC_LIBS</span></code>,
offered by some packages.  Therefore package configuration files should
avoid setting such variables before their calls to <code class="docutils literal notranslate"><span class="pre">find_dependency</span></code>.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.15: </span>Previously, the underlying call to <span class="target" id="index-5-command:find_package"></span><a class="reference internal" href="../command/find_package.html#command:find_package" title="find_package"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">find_package()</span></code></a> was always
optimized out if the package had already been found.  CMake 3.15
removed the optimization to support cases in which <code class="docutils literal notranslate"><span class="pre">find_dependency</span></code>
call arguments request different components.</p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.26: </span>The pre-3.15 optimization was restored, but with the above-described
heuristic to account for varying <code class="docutils literal notranslate"><span class="pre">find_dependency</span></code> call arguments.</p>
</div>
</section>
</section>


            <div class="clearer"></div>
          </div>
        </div>
      </div>
      <div class="sphinxsidebar" role="navigation" aria-label="main navigation">
        <div class="sphinxsidebarwrapper">
  <div>
    <h3><a href="../index.html">Table of Contents</a></h3>
    <ul>
<li><a class="reference internal" href="#">CMakeFindDependencyMacro</a><ul>
<li><a class="reference internal" href="#package-dependency-search-optimizations">Package Dependency Search Optimizations</a></li>
</ul>
</li>
</ul>

  </div>
  <div>
    <h4>Previous topic</h4>
    <p class="topless"><a href="CMakeDependentOption.html"
                          title="previous chapter">CMakeDependentOption</a></p>
  </div>
  <div>
    <h4>Next topic</h4>
    <p class="topless"><a href="CMakeFindFrameworks.html"
                          title="next chapter">CMakeFindFrameworks</a></p>
  </div>
  <div role="note" aria-label="source link">
    <h3>This Page</h3>
    <ul class="this-page-menu">
      <li><a href="../_sources/module/CMakeFindDependencyMacro.rst.txt"
            rel="nofollow">Show Source</a></li>
    </ul>
   </div>
<div id="searchbox" style="display: none" role="search">
  <h3 id="searchlabel">Quick search</h3>
    <div class="searchformwrapper">
    <form class="search" action="../search.html" method="get">
      <input type="text" name="q" aria-labelledby="searchlabel" autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false"/>
      <input type="submit" value="Go" />
    </form>
    </div>
</div>
<script>document.getElementById('searchbox').style.display = "block"</script>
        </div>
      </div>
      <div class="clearer"></div>
    </div>
    <div class="related" role="navigation" aria-label="related navigation">
      <h3>Navigation</h3>
      <ul>
        <li class="right" style="margin-right: 10px">
          <a href="../genindex.html" title="General Index"
             >index</a></li>
        <li class="right" >
          <a href="CMakeFindFrameworks.html" title="CMakeFindFrameworks"
             >next</a> |</li>
        <li class="right" >
          <a href="CMakeDependentOption.html" title="CMakeDependentOption"
             >previous</a> |</li>
  <li>
    <img src="../_static/cmake-logo-16.png" alt=""
         style="vertical-align: middle; margin-top: -2px" />
  </li>
  <li>
    <a href="https://cmake.org/">CMake</a> &#187;
  </li>
  <li>
    <a href="../index.html">3.27.9 Documentation</a> &#187;
  </li>

          <li class="nav-item nav-item-1"><a href="../manual/cmake-modules.7.html" >cmake-modules(7)</a> &#187;</li>
        <li class="nav-item nav-item-this"><a href="">CMakeFindDependencyMacro</a></li> 
      </ul>
    </div>

    <div class="footer" role="contentinfo">
        &#169; Copyright 2000-2023 Kitware, Inc. and Contributors.
      Created using <a href="https://www.sphinx-doc.org/">Sphinx</a> 5.3.0.
    </div>
  </body>
</html>