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  <section id="cmake-language">
<span id="command:cmake_language"></span><h1>cmake_language<a class="headerlink" href="#cmake-language" title="Permalink to this heading">¶</a></h1>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.18.</span></p>
</div>
<p>Call meta-operations on CMake commands.</p>
<section id="synopsis">
<h2>Synopsis<a class="headerlink" href="#synopsis" title="Permalink to this heading">¶</a></h2>
<pre class="literal-block">cmake_language(<a class="reference internal" href="#call">CALL</a> &lt;command&gt; [&lt;arg&gt;...])
cmake_language(<a class="reference internal" href="#eval">EVAL</a> CODE &lt;code&gt;...)
cmake_language(<a class="reference internal" href="#defer">DEFER</a> &lt;options&gt;... CALL &lt;command&gt; [&lt;arg&gt;...])
cmake_language(<a class="reference internal" href="#set-dependency-provider">SET_DEPENDENCY_PROVIDER</a> &lt;command&gt; SUPPORTED_METHODS &lt;methods&gt;...)
cmake_language(<a class="reference internal" href="#get-message-log-level">GET_MESSAGE_LOG_LEVEL</a> &lt;out-var&gt;)</pre>
</section>
<section id="introduction">
<h2>Introduction<a class="headerlink" href="#introduction" title="Permalink to this heading">¶</a></h2>
<p>This command will call meta-operations on built-in CMake commands or
those created via the <span class="target" id="index-0-command:macro"></span><a class="reference internal" href="macro.html#command:macro" title="macro"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">macro()</span></code></a> or <span class="target" id="index-0-command:function"></span><a class="reference internal" href="function.html#command:function" title="function"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">function()</span></code></a> commands.</p>
<p><code class="docutils literal notranslate"><span class="pre">cmake_language</span></code> does not introduce a new variable or policy scope.</p>
</section>
<section id="calling-commands">
<h2>Calling Commands<a class="headerlink" href="#calling-commands" title="Permalink to this heading">¶</a></h2>
<div class="highlight-cmake notranslate" id="call"><div class="highlight"><pre><span></span><span class="nf">cmake_language(</span><span class="no">CALL</span><span class="w"> </span><span class="nv">&lt;command&gt;</span><span class="w"> </span><span class="p">[</span><span class="nv">&lt;arg&gt;...</span><span class="p">]</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<p>Calls the named <code class="docutils literal notranslate"><span class="pre">&lt;command&gt;</span></code> with the given arguments (if any).
For example, the code:</p>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">set(</span><span class="nb">message_command</span><span class="w"> </span><span class="s">&quot;message&quot;</span><span class="nf">)</span><span class="w"></span>
<span class="nf">cmake_language(</span><span class="no">CALL</span><span class="w"> </span><span class="o">${</span><span class="nt">message_command</span><span class="o">}</span><span class="w"> </span><span class="no">STATUS</span><span class="w"> </span><span class="s">&quot;Hello World!&quot;</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<p>is equivalent to</p>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">message(</span><span class="no">STATUS</span><span class="w"> </span><span class="s">&quot;Hello World!&quot;</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>To ensure consistency of the code, the following commands are not allowed:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">if</span></code> / <code class="docutils literal notranslate"><span class="pre">elseif</span></code> / <code class="docutils literal notranslate"><span class="pre">else</span></code> / <code class="docutils literal notranslate"><span class="pre">endif</span></code></p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">block</span></code> / <code class="docutils literal notranslate"><span class="pre">endblock</span></code></p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">while</span></code> / <code class="docutils literal notranslate"><span class="pre">endwhile</span></code></p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">foreach</span></code> / <code class="docutils literal notranslate"><span class="pre">endforeach</span></code></p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">function</span></code> / <code class="docutils literal notranslate"><span class="pre">endfunction</span></code></p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">macro</span></code> / <code class="docutils literal notranslate"><span class="pre">endmacro</span></code></p></li>
</ul>
</div>
</section>
<section id="evaluating-code">
<h2>Evaluating Code<a class="headerlink" href="#evaluating-code" title="Permalink to this heading">¶</a></h2>
<div class="highlight-cmake notranslate" id="eval"><div class="highlight"><pre><span></span><span class="nf">cmake_language(</span><span class="no">EVAL</span><span class="w"> </span><span class="no">CODE</span><span class="w"> </span><span class="nv">&lt;code&gt;...</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<p>Evaluates the <code class="docutils literal notranslate"><span class="pre">&lt;code&gt;...</span></code> as CMake code.</p>
<p>For example, the code:</p>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">set(</span><span class="no">A</span><span class="w"> </span><span class="no">TRUE</span><span class="nf">)</span><span class="w"></span>
<span class="nf">set(</span><span class="no">B</span><span class="w"> </span><span class="no">TRUE</span><span class="nf">)</span><span class="w"></span>
<span class="nf">set(</span><span class="no">C</span><span class="w"> </span><span class="no">TRUE</span><span class="nf">)</span><span class="w"></span>
<span class="nf">set(</span><span class="nb">condition</span><span class="w"> </span><span class="s">&quot;(A AND B) OR C&quot;</span><span class="nf">)</span><span class="w"></span>

<span class="nf">cmake_language(</span><span class="no">EVAL</span><span class="w"> </span><span class="no">CODE</span><span class="w"> </span><span class="s">&quot;</span>
<span class="s">  if (${condition})</span>
<span class="s">    message(STATUS TRUE)</span>
<span class="s">  else()</span>
<span class="s">    message(STATUS FALSE)</span>
<span class="s">  endif()&quot;</span><span class="w"></span>
<span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<p>is equivalent to</p>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">set(</span><span class="no">A</span><span class="w"> </span><span class="no">TRUE</span><span class="nf">)</span><span class="w"></span>
<span class="nf">set(</span><span class="no">B</span><span class="w"> </span><span class="no">TRUE</span><span class="nf">)</span><span class="w"></span>
<span class="nf">set(</span><span class="no">C</span><span class="w"> </span><span class="no">TRUE</span><span class="nf">)</span><span class="w"></span>
<span class="nf">set(</span><span class="nb">condition</span><span class="w"> </span><span class="s">&quot;(A AND B) OR C&quot;</span><span class="nf">)</span><span class="w"></span>

<span class="nf">file(</span><span class="no">WRITE</span><span class="w"> </span><span class="o">${</span><span class="nt">CMAKE_CURRENT_BINARY_DIR</span><span class="o">}</span><span class="na">/eval.cmake</span><span class="w"> </span><span class="s">&quot;</span>
<span class="s">  if (${condition})</span>
<span class="s">    message(STATUS TRUE)</span>
<span class="s">  else()</span>
<span class="s">    message(STATUS FALSE)</span>
<span class="s">  endif()&quot;</span><span class="w"></span>
<span class="nf">)</span><span class="w"></span>

<span class="nf">include(</span><span class="o">${</span><span class="nt">CMAKE_CURRENT_BINARY_DIR</span><span class="o">}</span><span class="na">/eval.cmake</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
</section>
<section id="deferring-calls">
<h2>Deferring Calls<a class="headerlink" href="#deferring-calls" title="Permalink to this heading">¶</a></h2>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.19.</span></p>
</div>
<div class="highlight-cmake notranslate" id="defer"><div class="highlight"><pre><span></span><span class="nf">cmake_language(</span><span class="no">DEFER</span><span class="w"> </span><span class="nv">&lt;options&gt;...</span><span class="w"> </span><span class="no">CALL</span><span class="w"> </span><span class="nv">&lt;command&gt;</span><span class="w"> </span><span class="p">[</span><span class="nv">&lt;arg&gt;...</span><span class="p">]</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<p>Schedules a call to the named <code class="docutils literal notranslate"><span class="pre">&lt;command&gt;</span></code> with the given arguments (if any)
to occur at a later time.  By default, deferred calls are executed as if
written at the end of the current directory's <code class="docutils literal notranslate"><span class="pre">CMakeLists.txt</span></code> file,
except that they run even after a <span class="target" id="index-0-command:return"></span><a class="reference internal" href="return.html#command:return" title="return"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">return()</span></code></a> call.  Variable
references in arguments are evaluated at the time the deferred call is
executed.</p>
<p>The options are:</p>
<dl>
<dt><code class="docutils literal notranslate"><span class="pre">DIRECTORY</span> <span class="pre">&lt;dir&gt;</span></code></dt><dd><p>Schedule the call for the end of the given directory instead of the
current directory.  The <code class="docutils literal notranslate"><span class="pre">&lt;dir&gt;</span></code> may reference either a source
directory or its corresponding binary directory.  Relative paths are
treated as relative to the current source directory.</p>
<p>The given directory must be known to CMake, being either the top-level
directory or one added by <span class="target" id="index-0-command:add_subdirectory"></span><a class="reference internal" href="add_subdirectory.html#command:add_subdirectory" title="add_subdirectory"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">add_subdirectory()</span></code></a>.  Furthermore,
the given directory must not yet be finished processing.  This means
it can be the current directory or one of its ancestors.</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">ID</span> <span class="pre">&lt;id&gt;</span></code></dt><dd><p>Specify an identification for the deferred call.
The <code class="docutils literal notranslate"><span class="pre">&lt;id&gt;</span></code> may not be empty and may not begin with a capital letter <code class="docutils literal notranslate"><span class="pre">A-Z</span></code>.
The <code class="docutils literal notranslate"><span class="pre">&lt;id&gt;</span></code> may begin with an underscore (<code class="docutils literal notranslate"><span class="pre">_</span></code>) only if it was generated
automatically by an earlier call that used <code class="docutils literal notranslate"><span class="pre">ID_VAR</span></code> to get the id.</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">ID_VAR</span> <span class="pre">&lt;var&gt;</span></code></dt><dd><p>Specify a variable in which to store the identification for the
deferred call.  If <code class="docutils literal notranslate"><span class="pre">ID</span> <span class="pre">&lt;id&gt;</span></code> is not given, a new identification
will be generated and the generated id will start with an underscore (<code class="docutils literal notranslate"><span class="pre">_</span></code>).</p>
</dd>
</dl>
<p>The currently scheduled list of deferred calls may be retrieved:</p>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">cmake_language(</span><span class="no">DEFER</span><span class="w"> </span><span class="p">[</span><span class="no">DIRECTORY</span><span class="w"> </span><span class="nv">&lt;dir&gt;</span><span class="p">]</span><span class="w"> </span><span class="no">GET_CALL_IDS</span><span class="w"> </span><span class="nv">&lt;var&gt;</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<p>This will store in <code class="docutils literal notranslate"><span class="pre">&lt;var&gt;</span></code> a <a class="reference internal" href="../manual/cmake-language.7.html#cmake-language-lists"><span class="std std-ref">semicolon-separated list</span></a> of deferred call ids.  The ids are for the directory scope in which
the calls have been deferred to (i.e. where they will be executed), which can
be different to the scope in which they were created.  The <code class="docutils literal notranslate"><span class="pre">DIRECTORY</span></code>
option can be used to specify the scope for which to retrieve the call ids.
If that option is not given, the call ids for the current directory scope will
be returned.</p>
<p>Details of a specific call may be retrieved from its id:</p>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">cmake_language(</span><span class="no">DEFER</span><span class="w"> </span><span class="p">[</span><span class="no">DIRECTORY</span><span class="w"> </span><span class="nv">&lt;dir&gt;</span><span class="p">]</span><span class="w"> </span><span class="no">GET_CALL</span><span class="w"> </span><span class="nv">&lt;id&gt;</span><span class="w"> </span><span class="nv">&lt;var&gt;</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<p>This will store in <code class="docutils literal notranslate"><span class="pre">&lt;var&gt;</span></code> a <a class="reference internal" href="../manual/cmake-language.7.html#cmake-language-lists"><span class="std std-ref">semicolon-separated list</span></a> in which the first element is the name of the command to be
called, and the remaining elements are its unevaluated arguments (any
contained <code class="docutils literal notranslate"><span class="pre">;</span></code> characters are included literally and cannot be distinguished
from multiple arguments).  If multiple calls are scheduled with the same id,
this retrieves the first one.  If no call is scheduled with the given id in
the specified <code class="docutils literal notranslate"><span class="pre">DIRECTORY</span></code> scope (or the current directory scope if no
<code class="docutils literal notranslate"><span class="pre">DIRECTORY</span></code> option is given), this stores an empty string in the variable.</p>
<p>Deferred calls may be canceled by their id:</p>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">cmake_language(</span><span class="no">DEFER</span><span class="w"> </span><span class="p">[</span><span class="no">DIRECTORY</span><span class="w"> </span><span class="nv">&lt;dir&gt;</span><span class="p">]</span><span class="w"> </span><span class="no">CANCEL_CALL</span><span class="w"> </span><span class="nv">&lt;id&gt;...</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<p>This cancels all deferred calls matching any of the given ids in the specified
<code class="docutils literal notranslate"><span class="pre">DIRECTORY</span></code> scope (or the current directory scope if no <code class="docutils literal notranslate"><span class="pre">DIRECTORY</span></code> option
is given).  Unknown ids are silently ignored.</p>
<section id="deferred-call-examples">
<h3>Deferred Call Examples<a class="headerlink" href="#deferred-call-examples" title="Permalink to this heading">¶</a></h3>
<p>For example, the code:</p>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">cmake_language(</span><span class="no">DEFER</span><span class="w"> </span><span class="no">CALL</span><span class="w"> </span><span class="nb">message</span><span class="w"> </span><span class="s">&quot;${deferred_message}&quot;</span><span class="nf">)</span><span class="w"></span>
<span class="nf">cmake_language(</span><span class="no">DEFER</span><span class="w"> </span><span class="no">ID_VAR</span><span class="w"> </span><span class="nb">id</span><span class="w"> </span><span class="no">CALL</span><span class="w"> </span><span class="nb">message</span><span class="w"> </span><span class="s">&quot;Canceled Message&quot;</span><span class="nf">)</span><span class="w"></span>
<span class="nf">cmake_language(</span><span class="no">DEFER</span><span class="w"> </span><span class="no">CANCEL_CALL</span><span class="w"> </span><span class="o">${</span><span class="nt">id</span><span class="o">}</span><span class="nf">)</span><span class="w"></span>
<span class="nf">message(</span><span class="s">&quot;Immediate Message&quot;</span><span class="nf">)</span><span class="w"></span>
<span class="nf">set(</span><span class="nb">deferred_message</span><span class="w"> </span><span class="s">&quot;Deferred Message&quot;</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<p>prints:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>Immediate Message
Deferred Message
</pre></div>
</div>
<p>The <code class="docutils literal notranslate"><span class="pre">Cancelled</span> <span class="pre">Message</span></code> is never printed because its command is
canceled.  The <code class="docutils literal notranslate"><span class="pre">deferred_message</span></code> variable reference is not evaluated
until the call site, so it can be set after the deferred call is scheduled.</p>
<p>In order to evaluate variable references immediately when scheduling a
deferred call, wrap it using <code class="docutils literal notranslate"><span class="pre">cmake_language(EVAL)</span></code>.  However, note that
arguments will be re-evaluated in the deferred call, though that can be
avoided by using bracket arguments.  For example:</p>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">set(</span><span class="nb">deferred_message</span><span class="w"> </span><span class="s">&quot;Deferred Message 1&quot;</span><span class="nf">)</span><span class="w"></span>
<span class="nf">set(</span><span class="nb">re_evaluated</span><span class="w"> </span><span class="p">[[</span><span class="o">${</span><span class="nt">deferred_message</span><span class="o">}</span><span class="p">]]</span><span class="nf">)</span><span class="w"></span>
<span class="nf">cmake_language(</span><span class="no">EVAL</span><span class="w"> </span><span class="no">CODE</span><span class="w"> </span><span class="s">&quot;</span>
<span class="s">  cmake_language(DEFER CALL message [[${deferred_message}]])</span>
<span class="s">  cmake_language(DEFER CALL message \&quot;${re_evaluated}\&quot;)</span>
<span class="s">&quot;</span><span class="nf">)</span><span class="w"></span>
<span class="nf">message(</span><span class="s">&quot;Immediate Message&quot;</span><span class="nf">)</span><span class="w"></span>
<span class="nf">set(</span><span class="nb">deferred_message</span><span class="w"> </span><span class="s">&quot;Deferred Message 2&quot;</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<p>also prints:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>Immediate Message
Deferred Message 1
Deferred Message 2
</pre></div>
</div>
</section>
</section>
<section id="dependency-providers">
<span id="set-dependency-provider"></span><span id="id1"></span><h2>Dependency Providers<a class="headerlink" href="#dependency-providers" title="Permalink to this heading">¶</a></h2>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.24.</span></p>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>A high-level introduction to this feature can be found in the
<a class="reference internal" href="../guide/using-dependencies/index.html#dependency-providers-overview"><span class="std std-ref">Using Dependencies Guide</span></a>.</p>
</div>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">cmake_language(</span><span class="no">SET_DEPENDENCY_PROVIDER</span><span class="w"> </span><span class="nv">&lt;command&gt;</span><span class="w"></span>
<span class="w">               </span><span class="no">SUPPORTED_METHODS</span><span class="w"> </span><span class="nv">&lt;methods&gt;...</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<p>When a call is made to <span class="target" id="index-0-command:find_package"></span><a class="reference internal" href="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> or
<span class="target" id="index-0-command:fetchcontent_makeavailable"></span><a class="reference internal" href="../module/FetchContent.html#command:fetchcontent_makeavailable" title="fetchcontent_makeavailable"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">FetchContent_MakeAvailable()</span></code></a>, the call may be forwarded to a
dependency provider which then has the opportunity to fulfill the request.
If the request is for one of the <code class="docutils literal notranslate"><span class="pre">&lt;methods&gt;</span></code> specified when the provider
was set, CMake calls the provider's <code class="docutils literal notranslate"><span class="pre">&lt;command&gt;</span></code> with a set of
method-specific arguments.  If the provider does not fulfill the request,
or if the provider doesn't support the request's method, or no provider
is set, the built-in <span class="target" id="index-1-command:find_package"></span><a class="reference internal" href="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> or
<span class="target" id="index-1-command:fetchcontent_makeavailable"></span><a class="reference internal" href="../module/FetchContent.html#command:fetchcontent_makeavailable" title="fetchcontent_makeavailable"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">FetchContent_MakeAvailable()</span></code></a> implementation is used to fulfill
the request in the usual way.</p>
<p>One or more of the following values can be specified for the <code class="docutils literal notranslate"><span class="pre">&lt;methods&gt;</span></code>
when setting the provider:</p>
<dl class="simple">
<dt><code class="docutils literal notranslate"><span class="pre">FIND_PACKAGE</span></code></dt><dd><p>The provider command accepts <span class="target" id="index-2-command:find_package"></span><a class="reference internal" href="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> requests.</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">FETCHCONTENT_MAKEAVAILABLE_SERIAL</span></code></dt><dd><p>The provider command accepts <span class="target" id="index-2-command:fetchcontent_makeavailable"></span><a class="reference internal" href="../module/FetchContent.html#command:fetchcontent_makeavailable" title="fetchcontent_makeavailable"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">FetchContent_MakeAvailable()</span></code></a>
requests.  It expects each dependency to be fed to the provider command
one at a time, not the whole list in one go.</p>
</dd>
</dl>
<p>Only one provider can be set at any point in time.  If a provider is already
set when <code class="docutils literal notranslate"><span class="pre">cmake_language(SET_DEPENDENCY_PROVIDER)</span></code> is called, the new
provider replaces the previously set one.  The specified <code class="docutils literal notranslate"><span class="pre">&lt;command&gt;</span></code> must
already exist when <code class="docutils literal notranslate"><span class="pre">cmake_language(SET_DEPENDENCY_PROVIDER)</span></code> is called.
As a special case, providing an empty string for the <code class="docutils literal notranslate"><span class="pre">&lt;command&gt;</span></code> and no
<code class="docutils literal notranslate"><span class="pre">&lt;methods&gt;</span></code> will discard any previously set provider.</p>
<p>The dependency provider can only be set while processing one of the files
specified by the <span class="target" id="index-0-variable:CMAKE_PROJECT_TOP_LEVEL_INCLUDES"></span><a class="reference internal" href="../variable/CMAKE_PROJECT_TOP_LEVEL_INCLUDES.html#variable:CMAKE_PROJECT_TOP_LEVEL_INCLUDES" title="CMAKE_PROJECT_TOP_LEVEL_INCLUDES"><code class="xref cmake cmake-variable docutils literal notranslate"><span class="pre">CMAKE_PROJECT_TOP_LEVEL_INCLUDES</span></code></a> variable.
Thus, dependency providers can only be set as part of the first call to
<span class="target" id="index-0-command:project"></span><a class="reference internal" href="project.html#command:project" title="project"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">project()</span></code></a>.  Calling <code class="docutils literal notranslate"><span class="pre">cmake_language(SET_DEPENDENCY_PROVIDER)</span></code>
outside of that context will result in an error.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>The choice of dependency provider should always be under the user's control.
As a convenience, a project may choose to provide a file that users can
list in their <span class="target" id="index-1-variable:CMAKE_PROJECT_TOP_LEVEL_INCLUDES"></span><a class="reference internal" href="../variable/CMAKE_PROJECT_TOP_LEVEL_INCLUDES.html#variable:CMAKE_PROJECT_TOP_LEVEL_INCLUDES" title="CMAKE_PROJECT_TOP_LEVEL_INCLUDES"><code class="xref cmake cmake-variable docutils literal notranslate"><span class="pre">CMAKE_PROJECT_TOP_LEVEL_INCLUDES</span></code></a> variable, but
the use of such a file should always be the user's choice.</p>
</div>
<section id="provider-commands">
<h3>Provider commands<a class="headerlink" href="#provider-commands" title="Permalink to this heading">¶</a></h3>
<p>Providers define a single <code class="docutils literal notranslate"><span class="pre">&lt;command&gt;</span></code> to accept requests.  The name of
the command should be specific to that provider, not something overly
generic that another provider might also use.  This enables users to compose
different providers in their own custom provider.  The recommended form is
<code class="docutils literal notranslate"><span class="pre">xxx_provide_dependency()</span></code>, where <code class="docutils literal notranslate"><span class="pre">xxx</span></code> is the provider-specific part
(e.g. <code class="docutils literal notranslate"><span class="pre">vcpkg_provide_dependency()</span></code>, <code class="docutils literal notranslate"><span class="pre">conan_provide_dependency()</span></code>,
<code class="docutils literal notranslate"><span class="pre">ourcompany_provide_dependency()</span></code>, and so on).</p>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">xxx_provide_dependency(</span><span class="nv">&lt;method&gt;</span><span class="w"> </span><span class="p">[</span><span class="nv">&lt;method-specific-args&gt;...</span><span class="p">]</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<p>Because some methods expect certain variables to be set in the calling scope,
the provider command should typically be implemented as a macro rather than a
function.  This ensures it does not introduce a new variable scope.</p>
<p>The arguments CMake passes to the dependency provider depend on the type of
request.  The first argument is always the method, and it will only ever
be one of the <code class="docutils literal notranslate"><span class="pre">&lt;methods&gt;</span></code> that was specified when setting the provider.</p>
<dl>
<dt><code class="docutils literal notranslate"><span class="pre">FIND_PACKAGE</span></code></dt><dd><p>The <code class="docutils literal notranslate"><span class="pre">&lt;method-specific-args&gt;</span></code> will be everything passed to the
<span class="target" id="index-3-command:find_package"></span><a class="reference internal" href="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 that requested the dependency.  The first of
these <code class="docutils literal notranslate"><span class="pre">&lt;method-specific-args&gt;</span></code> will therefore always be the name of the
dependency.  Dependency names are case-sensitive for this method because
<span class="target" id="index-4-command:find_package"></span><a class="reference internal" href="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> treats them case-sensitively too.</p>
<p>If the provider command fulfills the request, it must set the same variable
that <span class="target" id="index-5-command:find_package"></span><a class="reference internal" href="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> expects to be set.  For a dependency named
<code class="docutils literal notranslate"><span class="pre">depName</span></code>, the provider must set <code class="docutils literal notranslate"><span class="pre">depName_FOUND</span></code> to true if it fulfilled
the request.  If the provider returns without setting this variable, CMake
will assume the request was not fulfilled and will fall back to the
built-in implementation.</p>
<p>If the provider needs to call the built-in <span class="target" id="index-6-command:find_package"></span><a class="reference internal" href="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>
implementation as part of its processing, it can do so by including the
<code class="docutils literal notranslate"><span class="pre">BYPASS_PROVIDER</span></code> keyword as one of the arguments.</p>
</dd>
<dt><code class="docutils literal notranslate"><span class="pre">FETCHCONTENT_MAKEAVAILABE_SERIAL</span></code></dt><dd><p>The <code class="docutils literal notranslate"><span class="pre">&lt;method-specific-args&gt;</span></code> will be everything passed to the
<span class="target" id="index-0-command:fetchcontent_declare"></span><a class="reference internal" href="../module/FetchContent.html#command:fetchcontent_declare" title="fetchcontent_declare"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">FetchContent_Declare()</span></code></a> call that corresponds to the requested
dependency, with the following exceptions:</p>
<ul class="simple">
<li><p>If <code class="docutils literal notranslate"><span class="pre">SOURCE_DIR</span></code> or <code class="docutils literal notranslate"><span class="pre">BINARY_DIR</span></code> were not part of the original
declared arguments, they will be added with their default values.</p></li>
<li><p>If <span class="target" id="index-0-variable:FETCHCONTENT_TRY_FIND_PACKAGE_MODE"></span><a class="reference internal" href="../module/FetchContent.html#variable:FETCHCONTENT_TRY_FIND_PACKAGE_MODE" title="FETCHCONTENT_TRY_FIND_PACKAGE_MODE"><code class="xref cmake cmake-variable docutils literal notranslate"><span class="pre">FETCHCONTENT_TRY_FIND_PACKAGE_MODE</span></code></a> is set to <code class="docutils literal notranslate"><span class="pre">NEVER</span></code>,
any <code class="docutils literal notranslate"><span class="pre">FIND_PACKAGE_ARGS</span></code> will be omitted.</p></li>
<li><p>The <code class="docutils literal notranslate"><span class="pre">OVERRIDE_FIND_PACKAGE</span></code> keyword is always omitted.</p></li>
</ul>
<p>The first of the <code class="docutils literal notranslate"><span class="pre">&lt;method-specific-args&gt;</span></code> will always be the name of the
dependency.  Dependency names are case-insensitive for this method because
<span class="target" id="index-0-module:FetchContent"></span><a class="reference internal" href="../module/FetchContent.html#module:FetchContent" title="FetchContent"><code class="xref cmake cmake-module docutils literal notranslate"><span class="pre">FetchContent</span></code></a> also treats them case-insensitively.</p>
<p>If the provider fulfills the request, it should call
<span class="target" id="index-0-command:fetchcontent_setpopulated"></span><a class="reference internal" href="../module/FetchContent.html#command:fetchcontent_setpopulated" title="fetchcontent_setpopulated"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">FetchContent_SetPopulated()</span></code></a>, passing the name of the dependency as
the first argument.  The <code class="docutils literal notranslate"><span class="pre">SOURCE_DIR</span></code> and <code class="docutils literal notranslate"><span class="pre">BINARY_DIR</span></code> arguments to that
command should only be given if the provider makes the dependency's source
and build directories available in exactly the same way as the built-in
<span class="target" id="index-3-command:fetchcontent_makeavailable"></span><a class="reference internal" href="../module/FetchContent.html#command:fetchcontent_makeavailable" title="fetchcontent_makeavailable"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">FetchContent_MakeAvailable()</span></code></a> command.</p>
<p>If the provider returns without calling <span class="target" id="index-1-command:fetchcontent_setpopulated"></span><a class="reference internal" href="../module/FetchContent.html#command:fetchcontent_setpopulated" title="fetchcontent_setpopulated"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">FetchContent_SetPopulated()</span></code></a>
for the named dependency, CMake will assume the request was not fulfilled
and will fall back to the built-in implementation.</p>
<p>Note that empty arguments may be significant for this method (e.g. an empty
string following a <code class="docutils literal notranslate"><span class="pre">GIT_SUBMODULES</span></code> keyword).  Therefore, if forwarding
these arguments on to another command, extra care must be taken to avoid such
arguments being silently dropped.</p>
<p>If <code class="docutils literal notranslate"><span class="pre">FETCHCONTENT_SOURCE_DIR_&lt;uppercaseDepName&gt;</span></code> is set, then the
dependency provider will never see requests for the <code class="docutils literal notranslate"><span class="pre">&lt;depName&gt;</span></code> dependency
for this method. When the user sets such a variable, they are explicitly
overriding where to get that dependency from and are taking on the
responsibility that their overriding version meets any requirements for that
dependency and is compatible with whatever else in the project uses it.
Depending on the value of <span class="target" id="index-1-variable:FETCHCONTENT_TRY_FIND_PACKAGE_MODE"></span><a class="reference internal" href="../module/FetchContent.html#variable:FETCHCONTENT_TRY_FIND_PACKAGE_MODE" title="FETCHCONTENT_TRY_FIND_PACKAGE_MODE"><code class="xref cmake cmake-variable docutils literal notranslate"><span class="pre">FETCHCONTENT_TRY_FIND_PACKAGE_MODE</span></code></a>
and whether the <code class="docutils literal notranslate"><span class="pre">OVERRIDE_FIND_PACKAGE</span></code> option was given to
<span class="target" id="index-1-command:fetchcontent_declare"></span><a class="reference internal" href="../module/FetchContent.html#command:fetchcontent_declare" title="fetchcontent_declare"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">FetchContent_Declare()</span></code></a>, having
<code class="docutils literal notranslate"><span class="pre">FETCHCONTENT_SOURCE_DIR_&lt;uppercaseDepName&gt;</span></code> set may also prevent the
dependency provider from seeing requests for a <code class="docutils literal notranslate"><span class="pre">find_package(depName)</span></code>
call too.</p>
</dd>
</dl>
</section>
<section id="provider-examples">
<h3>Provider Examples<a class="headerlink" href="#provider-examples" title="Permalink to this heading">¶</a></h3>
<p>This first example only intercepts <span class="target" id="index-7-command:find_package"></span><a class="reference internal" href="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> calls.  The
provider command runs an external tool which copies the relevant artifacts
into a provider-specific directory, if that tool knows about the dependency.
It then relies on the built-in implementation to then find those artifacts.
<span class="target" id="index-4-command:fetchcontent_makeavailable"></span><a class="reference internal" href="../module/FetchContent.html#command:fetchcontent_makeavailable" title="fetchcontent_makeavailable"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">FetchContent_MakeAvailable()</span></code></a> calls would not go through the provider.</p>
<div class="literal-block-wrapper docutils container" id="id2">
<div class="code-block-caption"><span class="caption-text">mycomp_provider.cmake</span><a class="headerlink" href="#id2" title="Permalink to this code">¶</a></div>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="c"># Always ensure we have the policy settings this provider expects</span>
<span class="nf">cmake_minimum_required(</span><span class="no">VERSION</span><span class="w"> </span><span class="m">3.24</span><span class="nf">)</span><span class="w"></span>

<span class="nf">set(</span><span class="no">MYCOMP_PROVIDER_INSTALL_DIR</span><span class="w"> </span><span class="o">${</span><span class="nt">CMAKE_BINARY_DIR</span><span class="o">}</span><span class="na">/mycomp_packages</span><span class="w"></span>
<span class="w">  </span><span class="no">CACHE</span><span class="w"> </span><span class="no">PATH</span><span class="w"> </span><span class="s">&quot;The directory this provider installs packages to&quot;</span><span class="w"></span>
<span class="nf">)</span><span class="w"></span>
<span class="c"># Tell the built-in implementation to look in our area first, unless</span>
<span class="c"># the find_package() call uses NO_..._PATH options to exclude it</span>
<span class="nf">list(</span><span class="no">APPEND</span><span class="w"> </span><span class="no">CMAKE_MODULE_PATH</span><span class="w"> </span><span class="o">${</span><span class="nt">MYCOMP_PROVIDER_INSTALL_DIR</span><span class="o">}</span><span class="na">/cmake</span><span class="nf">)</span><span class="w"></span>
<span class="nf">list(</span><span class="no">APPEND</span><span class="w"> </span><span class="no">CMAKE_PREFIX_PATH</span><span class="w"> </span><span class="o">${</span><span class="nt">MYCOMP_PROVIDER_INSTALL_DIR</span><span class="o">}</span><span class="nf">)</span><span class="w"></span>

<span class="nf">macro(</span><span class="nb">mycomp_provide_dependency</span><span class="w"> </span><span class="nb">method</span><span class="w"> </span><span class="nb">package_name</span><span class="nf">)</span><span class="w"></span>
<span class="w">  </span><span class="nf">execute_process(</span><span class="w"></span>
<span class="w">    </span><span class="no">COMMAND</span><span class="w"> </span><span class="nb">some_tool</span><span class="w"> </span><span class="o">${</span><span class="nt">package_name</span><span class="o">}</span><span class="w"> </span><span class="p">--</span><span class="nb">installdir</span><span class="w"> </span><span class="o">${</span><span class="nt">MYCOMP_PROVIDER_INSTALL_DIR</span><span class="o">}</span><span class="w"></span>
<span class="w">    </span><span class="no">COMMAND_ERROR_IS_FATAL</span><span class="w"> </span><span class="no">ANY</span><span class="w"></span>
<span class="w">  </span><span class="nf">)</span><span class="w"></span>
<span class="nf">endmacro()</span><span class="w"></span>

<span class="nf">cmake_language(</span><span class="w"></span>
<span class="w">  </span><span class="no">SET_DEPENDENCY_PROVIDER</span><span class="w"> </span><span class="nb">mycomp_provide_dependency</span><span class="w"></span>
<span class="w">  </span><span class="no">SUPPORTED_METHODS</span><span class="w"> </span><span class="no">FIND_PACKAGE</span><span class="w"></span>
<span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
</div>
<p>The user would then typically use the above file like so:</p>
<div class="highlight-none notranslate"><div class="highlight"><pre><span></span>cmake -DCMAKE_PROJECT_TOP_LEVEL_INCLUDES=/path/to/mycomp_provider.cmake ...
</pre></div>
</div>
<p>The next example demonstrates a provider that accepts both methods, but
only handles one specific dependency.  It enforces providing Google Test
using <span class="target" id="index-1-module:FetchContent"></span><a class="reference internal" href="../module/FetchContent.html#module:FetchContent" title="FetchContent"><code class="xref cmake cmake-module docutils literal notranslate"><span class="pre">FetchContent</span></code></a>, but leaves all other dependencies to be
fulfilled by CMake's built-in implementation.  It accepts a few different
names, which demonstrates one way of working around projects that hard-code
an unusual or undesirable way of adding this particular dependency to the
build.  The example also demonstrates how to use the <span class="target" id="index-0-command:list"></span><a class="reference internal" href="list.html#command:list" title="list"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">list()</span></code></a> command
to preserve variables that may be overwritten by a call to
<span class="target" id="index-5-command:fetchcontent_makeavailable"></span><a class="reference internal" href="../module/FetchContent.html#command:fetchcontent_makeavailable" title="fetchcontent_makeavailable"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">FetchContent_MakeAvailable()</span></code></a>.</p>
<div class="literal-block-wrapper docutils container" id="id3">
<div class="code-block-caption"><span class="caption-text">mycomp_provider.cmake</span><a class="headerlink" href="#id3" title="Permalink to this code">¶</a></div>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">cmake_minimum_required(</span><span class="no">VERSION</span><span class="w"> </span><span class="m">3.24</span><span class="nf">)</span><span class="w"></span>

<span class="c"># Because we declare this very early, it will take precedence over any</span>
<span class="c"># details the project might declare later for the same thing</span>
<span class="nf">include(</span><span class="nb">FetchContent</span><span class="nf">)</span><span class="w"></span>
<span class="nf">FetchContent_Declare(</span><span class="w"></span>
<span class="w">  </span><span class="nb">googletest</span><span class="w"></span>
<span class="w">  </span><span class="no">GIT_REPOSITORY</span><span class="w"> </span><span class="na">https://github.com/google/googletest.git</span><span class="w"></span>
<span class="w">  </span><span class="no">GIT_TAG</span><span class="w">        </span><span class="nb">e2239ee6043f73722e7aa812a459f54a28552929</span><span class="w"> </span><span class="c"># release-1.11.0</span>
<span class="nf">)</span><span class="w"></span>

<span class="c"># Both FIND_PACKAGE and FETCHCONTENT_MAKEAVAILABLE_SERIAL methods provide</span>
<span class="c"># the package or dependency name as the first method-specific argument.</span>
<span class="nf">macro(</span><span class="nb">mycomp_provide_dependency</span><span class="w"> </span><span class="nb">method</span><span class="w"> </span><span class="nb">dep_name</span><span class="nf">)</span><span class="w"></span>
<span class="w">  </span><span class="nf">if(</span><span class="s">&quot;${dep_name}&quot;</span><span class="w"> </span><span class="no">MATCHES</span><span class="w"> </span><span class="s">&quot;^(gtest|googletest)$&quot;</span><span class="nf">)</span><span class="w"></span>
<span class="w">    </span><span class="c"># Save our current command arguments in case we are called recursively</span>
<span class="w">    </span><span class="nf">list(</span><span class="no">APPEND</span><span class="w"> </span><span class="nb">mycomp_provider_args</span><span class="w"> </span><span class="o">${</span><span class="nt">method</span><span class="o">}</span><span class="w"> </span><span class="o">${</span><span class="nt">dep_name</span><span class="o">}</span><span class="nf">)</span><span class="w"></span>

<span class="w">    </span><span class="c"># This will forward to the built-in FetchContent implementation,</span>
<span class="w">    </span><span class="c"># which detects a recursive call for the same thing and avoids calling</span>
<span class="w">    </span><span class="c"># the provider again if dep_name is the same as the current call.</span>
<span class="w">    </span><span class="nf">FetchContent_MakeAvailable(</span><span class="nb">googletest</span><span class="nf">)</span><span class="w"></span>

<span class="w">    </span><span class="c"># Restore our command arguments</span>
<span class="w">    </span><span class="nf">list(</span><span class="no">POP_BACK</span><span class="w"> </span><span class="nb">mycomp_provider_args</span><span class="w"> </span><span class="nb">dep_name</span><span class="w"> </span><span class="nb">method</span><span class="nf">)</span><span class="w"></span>

<span class="w">    </span><span class="c"># Tell the caller we fulfilled the request</span>
<span class="w">    </span><span class="nf">if(</span><span class="s">&quot;${method}&quot;</span><span class="w"> </span><span class="no">STREQUAL</span><span class="w"> </span><span class="s">&quot;FIND_PACKAGE&quot;</span><span class="nf">)</span><span class="w"></span>
<span class="w">      </span><span class="c"># We need to set this if we got here from a find_package() call</span>
<span class="w">      </span><span class="c"># since we used a different method to fulfill the request.</span>
<span class="w">      </span><span class="c"># This example assumes projects only use the gtest targets,</span>
<span class="w">      </span><span class="c"># not any of the variables the FindGTest module may define.</span>
<span class="w">      </span><span class="nf">set(</span><span class="o">${</span><span class="nt">dep_name</span><span class="o">}</span><span class="nb">_FOUND</span><span class="w"> </span><span class="no">TRUE</span><span class="nf">)</span><span class="w"></span>
<span class="w">    </span><span class="nf">elseif(</span><span class="no">NOT</span><span class="w"> </span><span class="s">&quot;${dep_name}&quot;</span><span class="w"> </span><span class="no">STREQUAL</span><span class="w"> </span><span class="s">&quot;googletest&quot;</span><span class="nf">)</span><span class="w"></span>
<span class="w">      </span><span class="c"># We used the same method, but were given a different name to the</span>
<span class="w">      </span><span class="c"># one we populated with. Tell the caller about the name it used.</span>
<span class="w">      </span><span class="nf">FetchContent_SetPopulated(</span><span class="o">${</span><span class="nt">dep_name</span><span class="o">}</span><span class="w"></span>
<span class="w">        </span><span class="no">SOURCE_DIR</span><span class="w"> </span><span class="s">&quot;${googletest_SOURCE_DIR}&quot;</span><span class="w"></span>
<span class="w">        </span><span class="no">BINARY_DIR</span><span class="w"> </span><span class="s">&quot;${googletest_BINARY_DIR}&quot;</span><span class="w"></span>
<span class="w">      </span><span class="nf">)</span><span class="w"></span>
<span class="w">    </span><span class="nf">endif()</span><span class="w"></span>
<span class="w">  </span><span class="nf">endif()</span><span class="w"></span>
<span class="nf">endmacro()</span><span class="w"></span>

<span class="nf">cmake_language(</span><span class="w"></span>
<span class="w">  </span><span class="no">SET_DEPENDENCY_PROVIDER</span><span class="w"> </span><span class="nb">mycomp_provide_dependency</span><span class="w"></span>
<span class="w">  </span><span class="no">SUPPORTED_METHODS</span><span class="w"></span>
<span class="w">    </span><span class="no">FIND_PACKAGE</span><span class="w"></span>
<span class="w">    </span><span class="no">FETCHCONTENT_MAKEAVAILABLE_SERIAL</span><span class="w"></span>
<span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
</div>
<p>The final example demonstrates how to modify arguments to a
<span class="target" id="index-8-command:find_package"></span><a class="reference internal" href="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.  It forces all such calls to have the
<code class="docutils literal notranslate"><span class="pre">QUIET</span></code> keyword.  It uses the <code class="docutils literal notranslate"><span class="pre">BYPASS_PROVIDER</span></code> keyword to prevent
calling the provider command recursively for the same dependency.</p>
<div class="literal-block-wrapper docutils container" id="id4">
<div class="code-block-caption"><span class="caption-text">mycomp_provider.cmake</span><a class="headerlink" href="#id4" title="Permalink to this code">¶</a></div>
<div class="highlight-cmake notranslate"><div class="highlight"><pre><span></span><span class="nf">cmake_minimum_required(</span><span class="no">VERSION</span><span class="w"> </span><span class="m">3.24</span><span class="nf">)</span><span class="w"></span>

<span class="nf">macro(</span><span class="nb">mycomp_provide_dependency</span><span class="w"> </span><span class="nb">method</span><span class="nf">)</span><span class="w"></span>
<span class="w">  </span><span class="nf">find_package(</span><span class="o">${</span><span class="nt">ARGN</span><span class="o">}</span><span class="w"> </span><span class="no">BYPASS_PROVIDER</span><span class="w"> </span><span class="no">QUIET</span><span class="nf">)</span><span class="w"></span>
<span class="nf">endmacro()</span><span class="w"></span>

<span class="nf">cmake_language(</span><span class="w"></span>
<span class="w">  </span><span class="no">SET_DEPENDENCY_PROVIDER</span><span class="w"> </span><span class="nb">mycomp_provide_dependency</span><span class="w"></span>
<span class="w">  </span><span class="no">SUPPORTED_METHODS</span><span class="w"> </span><span class="no">FIND_PACKAGE</span><span class="w"></span>
<span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
</div>
</section>
</section>
<section id="getting-current-message-log-level">
<h2>Getting current message log level<a class="headerlink" href="#getting-current-message-log-level" title="Permalink to this heading">¶</a></h2>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.25.</span></p>
</div>
<div class="highlight-cmake notranslate" id="query-message-log-level"><span id="get-message-log-level"></span><div class="highlight"><pre><span></span><span class="nf">cmake_language(</span><span class="no">GET_MESSAGE_LOG_LEVEL</span><span class="w"> </span><span class="nv">&lt;output_variable&gt;</span><span class="nf">)</span><span class="w"></span>
</pre></div>
</div>
<p>Writes the current <span class="target" id="index-0-command:message"></span><a class="reference internal" href="message.html#command:message" title="message"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">message()</span></code></a> logging level
into the given <code class="docutils literal notranslate"><span class="pre">&lt;output_variable&gt;</span></code>.</p>
<p>See <span class="target" id="index-1-command:message"></span><a class="reference internal" href="message.html#command:message" title="message"><code class="xref cmake cmake-command docutils literal notranslate"><span class="pre">message()</span></code></a> for the possible logging levels.</p>
<p>The current message logging level can be set either using the
<a class="reference internal" href="../manual/cmake.1.html#cmdoption-cmake-log-level"><code class="xref std std-option docutils literal notranslate"><span class="pre">--log-level</span></code></a>
command line option of the <span class="target" id="index-0-manual:cmake(1)"></span><a class="reference internal" href="../manual/cmake.1.html#manual:cmake(1)" title="cmake(1)"><code class="xref cmake cmake-manual docutils literal notranslate"><span class="pre">cmake(1)</span></code></a> program or using
the <span class="target" id="index-0-variable:CMAKE_MESSAGE_LOG_LEVEL"></span><a class="reference internal" href="../variable/CMAKE_MESSAGE_LOG_LEVEL.html#variable:CMAKE_MESSAGE_LOG_LEVEL" title="CMAKE_MESSAGE_LOG_LEVEL"><code class="xref cmake cmake-variable docutils literal notranslate"><span class="pre">CMAKE_MESSAGE_LOG_LEVEL</span></code></a> variable.</p>
<p>If both the command line option and the variable are set, the command line
option takes precedence. If neither are set, the default logging level
is returned.</p>
</section>
</section>


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    <ul>
<li><a class="reference internal" href="#">cmake_language</a><ul>
<li><a class="reference internal" href="#synopsis">Synopsis</a></li>
<li><a class="reference internal" href="#introduction">Introduction</a></li>
<li><a class="reference internal" href="#calling-commands">Calling Commands</a></li>
<li><a class="reference internal" href="#evaluating-code">Evaluating Code</a></li>
<li><a class="reference internal" href="#deferring-calls">Deferring Calls</a><ul>
<li><a class="reference internal" href="#deferred-call-examples">Deferred Call Examples</a></li>
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<li><a class="reference internal" href="#dependency-providers">Dependency Providers</a><ul>
<li><a class="reference internal" href="#provider-commands">Provider commands</a></li>
<li><a class="reference internal" href="#provider-examples">Provider Examples</a></li>
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<li><a class="reference internal" href="#getting-current-message-log-level">Getting current message log level</a></li>
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