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                4.1
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              <p class="caption"><span class="caption-text">Contents:</span></p>
<ul class="current">
<li class="toctree-l1"><a class="reference internal" href="installation.html">Installation</a></li>
<li class="toctree-l1 current"><a class="current reference internal" href="#">Gcovr User Guide</a><ul>
<li class="toctree-l2"><a class="reference internal" href="#getting-started">Getting Started</a><ul>
<li class="toctree-l3"><a class="reference internal" href="#tabular-output-of-code-coverage">Tabular Output of Code Coverage</a></li>
<li class="toctree-l3"><a class="reference internal" href="#tabular-output-of-branch-coverage">Tabular Output of Branch Coverage</a></li>
<li class="toctree-l3"><a class="reference internal" href="#xml-output">XML Output</a></li>
<li class="toctree-l3"><a class="reference internal" href="#html-output">HTML Output</a></li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="#the-gcovr-command">The gcovr Command</a><ul>
<li class="toctree-l3"><a class="reference internal" href="#gcovr">gcovr</a><ul>
<li class="toctree-l4"><a class="reference internal" href="#options">Options</a></li>
<li class="toctree-l4"><a class="reference internal" href="#output-options">Output Options</a></li>
<li class="toctree-l4"><a class="reference internal" href="#filter-options">Filter Options</a></li>
<li class="toctree-l4"><a class="reference internal" href="#gcov-options">GCOV Options</a></li>
</ul>
</li>
</ul>
</li>
<li class="toctree-l2"><a class="reference internal" href="#using-filters">Using Filters</a><ul>
<li class="toctree-l3"><a class="reference internal" href="#speeding-up-coverage-data-search">Speeding up coverage data search</a></li>
<li class="toctree-l3"><a class="reference internal" href="#filters-for-symlinks">Filters for symlinks</a></li>
</ul>
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<li class="toctree-l2"><a class="reference internal" href="#acknowledgements">Acknowledgements</a></li>
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<li class="toctree-l1"><a class="reference internal" href="cookbook.html">Gcovr Cookbook</a></li>
<li class="toctree-l1"><a class="reference internal" href="faq.html">Frequently Asked Questions</a></li>
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  <div class="section" id="gcovr-user-guide">
<h1>Gcovr User Guide<a class="headerlink" href="#gcovr-user-guide" title="Permalink to this headline">¶</a></h1>
<p>Gcovr provides a utility for managing the use of the GNU <a class="reference external" href="http://gcc.gnu.org/onlinedocs/gcc/Gcov.html">gcov</a> utility
and generating summarized code coverage results. This command is
inspired by the Python <a class="reference external" href="http://nedbatchelder.com/code/coverage/">coverage.py</a> package, which provides a similar
utility for Python.</p>
<p>The <code class="docutils literal notranslate"><span class="pre">gcovr</span></code> command can produce different kinds of coverage reports:</p>
<ul class="simple">
<li>default: compact human-readable summaries</li>
<li><code class="docutils literal notranslate"><span class="pre">--xml</span></code>: machine readable XML reports in <a class="reference external" href="http://cobertura.sourceforge.net/">Cobertura</a> format</li>
<li><code class="docutils literal notranslate"><span class="pre">--html</span></code>: HTML summaries</li>
<li><code class="docutils literal notranslate"><span class="pre">--html-details</span></code>: HTML report with annotated source files</li>
</ul>
<p>Thus, gcovr can be viewed
as a command-line alternative to the <a class="reference external" href="http://ltp.sourceforge.net/coverage/lcov.php">lcov</a> utility, which runs gcov
and generates an HTML-formatted report.
The development of gcovr was motivated by the need for
text summaries and XML reports.</p>
<p>The <a class="reference external" href="http://gcovr.com">Gcovr Home Page</a> is
<a class="reference external" href="http://gcovr.com">http://gcovr.com</a>.
Automated test results are available through
<a class="reference external" href="https://travis-ci.org/gcovr/gcovr">Travis CI</a> and
<a class="reference external" href="https://ci.appveyor.com/project/latk/gcovr-0p8sb/branch/master">Appveyor</a>.
Gcovr is available under the
<a class="reference external" href="http://www.gnu.org/licenses/bsd.html">BSD</a> license.</p>
<p>This documentation describes Gcovr 4.1.</p>
<p>This User Guide provides the following sections:</p>
<div class="contents local topic" id="contents">
<ul class="simple">
<li><a class="reference internal" href="#getting-started" id="id1">Getting Started</a><ul>
<li><a class="reference internal" href="#tabular-output-of-code-coverage" id="id2">Tabular Output of Code Coverage</a></li>
<li><a class="reference internal" href="#tabular-output-of-branch-coverage" id="id3">Tabular Output of Branch Coverage</a></li>
<li><a class="reference internal" href="#xml-output" id="id4">XML Output</a></li>
<li><a class="reference internal" href="#html-output" id="id5">HTML Output</a></li>
</ul>
</li>
<li><a class="reference internal" href="#the-gcovr-command" id="id6">The gcovr Command</a><ul>
<li><a class="reference internal" href="#gcovr" id="id7">gcovr</a></li>
</ul>
</li>
<li><a class="reference internal" href="#using-filters" id="id8">Using Filters</a><ul>
<li><a class="reference internal" href="#speeding-up-coverage-data-search" id="id9">Speeding up coverage data search</a></li>
<li><a class="reference internal" href="#filters-for-symlinks" id="id10">Filters for symlinks</a></li>
</ul>
</li>
<li><a class="reference internal" href="#acknowledgements" id="id11">Acknowledgements</a></li>
</ul>
</div>
<p>Related documents:</p>
<ul class="simple">
<li><a class="reference internal" href="installation.html"><span class="doc">Installation</span></a></li>
<li><a class="reference internal" href="contributing.html"><span class="doc">Contributing</span></a> (includes instructions for bug reports)</li>
<li><a class="reference internal" href="cookbook.html"><span class="doc">Gcovr Cookbook</span></a></li>
<li><a class="reference internal" href="faq.html"><span class="doc">Frequently Asked Questions</span></a></li>
<li><a class="reference internal" href="changelog.html"><span class="doc">Change Log</span></a></li>
<li><a class="reference internal" href="license.html"><span class="doc">License</span></a></li>
</ul>
<div class="section" id="getting-started">
<h2><a class="toc-backref" href="#id1">Getting Started</a><a class="headerlink" href="#getting-started" title="Permalink to this headline">¶</a></h2>
<p>The <code class="docutils literal notranslate"><span class="pre">gcovr</span></code> command provides a summary of the lines that have been
executed in a program.  Code coverage statistics help you discover
untested parts of a program, which is particularly important when
assessing code quality.  Well-tested code is a characteristic of
high quality code, and software developers often assess code coverage
statistics when deciding if software is ready for a release.</p>
<p>The <code class="docutils literal notranslate"><span class="pre">gcovr</span></code> command can be used to analyze programs compiled with
GCC.   The following sections illustrate the application of <code class="docutils literal notranslate"><span class="pre">gcovr</span></code>
to test coverage of the following program:</p>
<pre class="code cpp literal-block">
<span class="ln"> 1 </span><span class="comment single">// example.cpp
</span><span class="ln"> 2 </span><span class="comment single"></span>
<span class="ln"> 3 </span><span class="keyword type">int</span> <span class="name function">foo</span><span class="punctuation">(</span><span class="keyword type">int</span> <span class="name">param</span><span class="punctuation">)</span>
<span class="ln"> 4 </span><span class="punctuation">{</span>
<span class="ln"> 5 </span>    <span class="keyword">if</span> <span class="punctuation">(</span><span class="name">param</span><span class="punctuation">)</span>
<span class="ln"> 6 </span>    <span class="punctuation">{</span>
<span class="ln"> 7 </span>        <span class="keyword">return</span> <span class="literal number integer">1</span><span class="punctuation">;</span>
<span class="ln"> 8 </span>    <span class="punctuation">}</span>
<span class="ln"> 9 </span>    <span class="keyword">else</span>
<span class="ln">10 </span>    <span class="punctuation">{</span>
<span class="ln">11 </span>        <span class="keyword">return</span> <span class="literal number integer">0</span><span class="punctuation">;</span>
<span class="ln">12 </span>    <span class="punctuation">}</span>
<span class="ln">13 </span><span class="punctuation">}</span>
<span class="ln">14 </span>
<span class="ln">15 </span><span class="keyword type">int</span> <span class="name function">main</span><span class="punctuation">(</span><span class="keyword type">int</span> <span class="name">argc</span><span class="punctuation">,</span> <span class="keyword type">char</span><span class="operator">*</span> <span class="name">argv</span><span class="punctuation">[])</span>
<span class="ln">16 </span><span class="punctuation">{</span>
<span class="ln">17 </span>    <span class="name">foo</span><span class="punctuation">(</span><span class="literal number integer">0</span><span class="punctuation">);</span>
<span class="ln">18 </span>
<span class="ln">19 </span>    <span class="keyword">return</span> <span class="literal number integer">0</span><span class="punctuation">;</span>
<span class="ln">20 </span><span class="punctuation">}</span>
</pre>
<p>This code executes several subroutines in this program,
but some lines in the program are not executed.</p>
<div class="section" id="tabular-output-of-code-coverage">
<h3><a class="toc-backref" href="#id2">Tabular Output of Code Coverage</a><a class="headerlink" href="#tabular-output-of-code-coverage" title="Permalink to this headline">¶</a></h3>
<p>We compile <code class="docutils literal notranslate"><span class="pre">example1.cpp</span></code> with the GCC compiler as follows:</p>
<pre class="code bash literal-block">
g++ -fprofile-arcs -ftest-coverage -fPIC -O0 example.cpp -o program
</pre>
<p>Note that we compile this program without optimization, because
optimization may combine lines of code and otherwise change the
flow of execution in the program.  Additionally, we compile with
the <code class="docutils literal notranslate"><span class="pre">-fprofile-arcs</span> <span class="pre">-ftest-coverage</span> <span class="pre">-fPIC</span></code> compiler options, which
add logic to generate output files that can be processed by the
<code class="docutils literal notranslate"><span class="pre">gcov</span></code> command.</p>
<p>The compiler generates the <code class="docutils literal notranslate"><span class="pre">program</span></code> executable.  When we execute this command:</p>
<pre class="code bash literal-block">
./program
</pre>
<p>the files <code class="docutils literal notranslate"><span class="pre">example1.gcno</span></code> and <code class="docutils literal notranslate"><span class="pre">example1.gcda</span></code> are generated.  These
files are processed with by <code class="docutils literal notranslate"><span class="pre">gcov</span></code> to generate code coverage
statistics.  The <code class="docutils literal notranslate"><span class="pre">gcovr</span></code> command calls <code class="docutils literal notranslate"><span class="pre">gcov</span></code> and summarizes these
code coverage statistics in various formats.  For example:</p>
<pre class="code bash literal-block">
gcovr -r .
</pre>
<p>generates a text summary of the lines executed:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="o">------------------------------------------------------------------------------</span>
                           <span class="n">GCC</span> <span class="n">Code</span> <span class="n">Coverage</span> <span class="n">Report</span>
<span class="n">Directory</span><span class="p">:</span> <span class="o">.</span>
<span class="o">------------------------------------------------------------------------------</span>
<span class="n">File</span>                                       <span class="n">Lines</span>    <span class="n">Exec</span>  <span class="n">Cover</span>   <span class="n">Missing</span>
<span class="o">------------------------------------------------------------------------------</span>
<span class="n">example</span><span class="o">.</span><span class="n">cpp</span>                                    <span class="mi">7</span>       <span class="mi">6</span>    <span class="mi">85</span><span class="o">%</span>   <span class="mi">7</span>
<span class="o">------------------------------------------------------------------------------</span>
<span class="n">TOTAL</span>                                          <span class="mi">7</span>       <span class="mi">6</span>    <span class="mi">85</span><span class="o">%</span>
<span class="o">------------------------------------------------------------------------------</span>
</pre></div>
</div>
<p>Each line of this output includes a summary for a given source file,
including the number of lines instrumented, the number of lines
executed, the percentage of lines executed, and a summary of the
line numbers that were not executed.  To improve clarity, gcovr
uses an aggressive approach to grouping uncovered lines and will
combine uncovered lines separated by “non-code” lines (blank,
freestanding braces, and single-line comments) into a single region.
As a result, the number of lines listed in the “Missing” list may
be greater than the difference of the “Lines” and “Exec” columns.</p>
<p>The <code class="docutils literal notranslate"><span class="pre">-r</span></code> option specifies the root directory for the files that are
being analyzed.  This allows <code class="docutils literal notranslate"><span class="pre">gcovr</span></code> to generate a simpler report
(without absolute path names), and it allows system header files
to be excluded from the analysis.</p>
<p>Note that <code class="docutils literal notranslate"><span class="pre">gcov</span></code> accumulates statistics by line.  Consequently, it
works best with a programming style that places only one statement
on each line.</p>
</div>
<div class="section" id="tabular-output-of-branch-coverage">
<h3><a class="toc-backref" href="#id3">Tabular Output of Branch Coverage</a><a class="headerlink" href="#tabular-output-of-branch-coverage" title="Permalink to this headline">¶</a></h3>
<p>The <code class="docutils literal notranslate"><span class="pre">gcovr</span></code> command can also summarize branch coverage using the <code class="docutils literal notranslate"><span class="pre">--branches</span></code> option:</p>
<pre class="code bash literal-block">
gcovr -r . --branches
</pre>
<p>This generates a tabular output that summarizes the number of branches, the number of
branches taken and the branches that were not completely covered:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="o">------------------------------------------------------------------------------</span>
                           <span class="n">GCC</span> <span class="n">Code</span> <span class="n">Coverage</span> <span class="n">Report</span>
<span class="n">Directory</span><span class="p">:</span> <span class="o">.</span>
<span class="o">------------------------------------------------------------------------------</span>
<span class="n">File</span>                                    <span class="n">Branches</span>   <span class="n">Taken</span>  <span class="n">Cover</span>   <span class="n">Missing</span>
<span class="o">------------------------------------------------------------------------------</span>
<span class="n">example</span><span class="o">.</span><span class="n">cpp</span>                                    <span class="mi">2</span>       <span class="mi">1</span>    <span class="mi">50</span><span class="o">%</span>   <span class="mi">5</span>
<span class="o">------------------------------------------------------------------------------</span>
<span class="n">TOTAL</span>                                          <span class="mi">2</span>       <span class="mi">1</span>    <span class="mi">50</span><span class="o">%</span>
<span class="o">------------------------------------------------------------------------------</span>
</pre></div>
</div>
</div>
<div class="section" id="xml-output">
<h3><a class="toc-backref" href="#id4">XML Output</a><a class="headerlink" href="#xml-output" title="Permalink to this headline">¶</a></h3>
<p>The default output format for <code class="docutils literal notranslate"><span class="pre">gcovr</span></code> is to generate a tabular
summary in plain text.  The <code class="docutils literal notranslate"><span class="pre">gcovr</span></code> command can also generate an
XML output using the <code class="docutils literal notranslate"><span class="pre">--xml</span></code> and <code class="docutils literal notranslate"><span class="pre">--xml-pretty</span></code> options:</p>
<pre class="code bash literal-block">
gcovr -r . --xml-pretty
</pre>
<p>This generates an XML summary of the lines executed:</p>
<pre class="code xml literal-block">
<span class="comment preproc">&lt;?xml version=&quot;1.0&quot; ?&gt;</span>
<span class="comment preproc">&lt;!DOCTYPE coverage
  SYSTEM 'http://cobertura.sourceforge.net/xml/coverage-04.dtd'&gt;</span>
<span class="name tag">&lt;coverage</span> <span class="name attribute">branch-rate=</span><span class="literal string">&quot;0.5&quot;</span> <span class="name attribute">branches-covered=</span><span class="literal string">&quot;1&quot;</span> <span class="name attribute">branches-valid=</span><span class="literal string">&quot;2&quot;</span>
 <span class="name attribute">complexity=</span><span class="literal string">&quot;0.0&quot;</span> <span class="name attribute">line-rate=</span><span class="literal string">&quot;0.8571428571428571&quot;</span> <span class="name attribute">lines-covered=</span><span class="literal string">&quot;6&quot;</span>
 <span class="name attribute">lines-valid=</span><span class="literal string">&quot;7&quot;</span> <span class="name attribute">timestamp=</span><span class="literal string">&quot;1530565116&quot;</span> <span class="name attribute">version=</span><span class="literal string">&quot;gcovr 4.1&quot;</span><span class="name tag">&gt;</span>
 <span class="name tag">&lt;sources&gt;</span>
  <span class="name tag">&lt;source&gt;</span>.<span class="name tag">&lt;/source&gt;</span>
 <span class="name tag">&lt;/sources&gt;</span>
 <span class="name tag">&lt;packages&gt;</span>
  <span class="name tag">&lt;package</span> <span class="name attribute">branch-rate=</span><span class="literal string">&quot;0.5&quot;</span> <span class="name attribute">complexity=</span><span class="literal string">&quot;0.0&quot;</span> <span class="name attribute">line-rate=</span><span class="literal string">&quot;0.8571428571428571&quot;</span>
   <span class="name attribute">name=</span><span class="literal string">&quot;&quot;</span><span class="name tag">&gt;</span>
   <span class="name tag">&lt;classes&gt;</span>
    <span class="name tag">&lt;class</span> <span class="name attribute">branch-rate=</span><span class="literal string">&quot;0.5&quot;</span> <span class="name attribute">complexity=</span><span class="literal string">&quot;0.0&quot;</span> <span class="name attribute">filename=</span><span class="literal string">&quot;example.cpp&quot;</span>
     <span class="name attribute">line-rate=</span><span class="literal string">&quot;0.8571428571428571&quot;</span> <span class="name attribute">name=</span><span class="literal string">&quot;example_cpp&quot;</span><span class="name tag">&gt;</span>
     <span class="name tag">&lt;methods/&gt;</span>
     <span class="name tag">&lt;lines&gt;</span>
      <span class="name tag">&lt;line</span> <span class="name attribute">branch=</span><span class="literal string">&quot;false&quot;</span> <span class="name attribute">hits=</span><span class="literal string">&quot;1&quot;</span> <span class="name attribute">number=</span><span class="literal string">&quot;3&quot;</span><span class="name tag">/&gt;</span>
      <span class="name tag">&lt;line</span> <span class="name attribute">branch=</span><span class="literal string">&quot;true&quot;</span> <span class="name attribute">condition-coverage=</span><span class="literal string">&quot;50% (1/2)&quot;</span> <span class="name attribute">hits=</span><span class="literal string">&quot;1&quot;</span> <span class="name attribute">number=</span><span class="literal string">&quot;5&quot;</span><span class="name tag">&gt;</span>
       <span class="name tag">&lt;conditions&gt;</span>
        <span class="name tag">&lt;condition</span> <span class="name attribute">coverage=</span><span class="literal string">&quot;50%&quot;</span> <span class="name attribute">number=</span><span class="literal string">&quot;0&quot;</span> <span class="name attribute">type=</span><span class="literal string">&quot;jump&quot;</span><span class="name tag">/&gt;</span>
       <span class="name tag">&lt;/conditions&gt;</span>
      <span class="name tag">&lt;/line&gt;</span>
      <span class="name tag">&lt;line</span> <span class="name attribute">branch=</span><span class="literal string">&quot;false&quot;</span> <span class="name attribute">hits=</span><span class="literal string">&quot;0&quot;</span> <span class="name attribute">number=</span><span class="literal string">&quot;7&quot;</span><span class="name tag">/&gt;</span>
      <span class="name tag">&lt;line</span> <span class="name attribute">branch=</span><span class="literal string">&quot;false&quot;</span> <span class="name attribute">hits=</span><span class="literal string">&quot;1&quot;</span> <span class="name attribute">number=</span><span class="literal string">&quot;11&quot;</span><span class="name tag">/&gt;</span>
      <span class="name tag">&lt;line</span> <span class="name attribute">branch=</span><span class="literal string">&quot;false&quot;</span> <span class="name attribute">hits=</span><span class="literal string">&quot;1&quot;</span> <span class="name attribute">number=</span><span class="literal string">&quot;15&quot;</span><span class="name tag">/&gt;</span>
      <span class="name tag">&lt;line</span> <span class="name attribute">branch=</span><span class="literal string">&quot;false&quot;</span> <span class="name attribute">hits=</span><span class="literal string">&quot;1&quot;</span> <span class="name attribute">number=</span><span class="literal string">&quot;17&quot;</span><span class="name tag">/&gt;</span>
      <span class="name tag">&lt;line</span> <span class="name attribute">branch=</span><span class="literal string">&quot;false&quot;</span> <span class="name attribute">hits=</span><span class="literal string">&quot;1&quot;</span> <span class="name attribute">number=</span><span class="literal string">&quot;19&quot;</span><span class="name tag">/&gt;</span>
     <span class="name tag">&lt;/lines&gt;</span>
    <span class="name tag">&lt;/class&gt;</span>
   <span class="name tag">&lt;/classes&gt;</span>
  <span class="name tag">&lt;/package&gt;</span>
 <span class="name tag">&lt;/packages&gt;</span>
<span class="name tag">&lt;/coverage&gt;</span>
</pre>
<p>This XML format is in the
<a class="reference external" href="http://cobertura.sourceforge.net/xml/coverage-04.dtd">Cobertura XML</a>
format suitable for import and display within the
<a class="reference external" href="http://www.jenkins-ci.org/">Jenkins</a> and <a class="reference external" href="http://www.hudson-ci.org/">Hudson</a>
continuous integration servers using the
<a class="reference external" href="https://wiki.jenkins-ci.org/display/JENKINS/Cobertura+Plugin">Cobertura Plugin</a>.</p>
<p>The <code class="docutils literal notranslate"><span class="pre">--xml</span></code> option generates a denser XML output, and the <code class="docutils literal notranslate"><span class="pre">--xml-pretty</span></code>
option generates an indented XML output that is easier to read.
Note that the XML output contains more information than the tabular
summary.  The tabular summary shows the percentage of covered lines,
while the XML output includes branch statistics and the number of
times that each line was covered.  Consequently, XML output can be
used to support performance optimization in the same manner that
<code class="docutils literal notranslate"><span class="pre">gcov</span></code> does.</p>
</div>
<div class="section" id="html-output">
<h3><a class="toc-backref" href="#id5">HTML Output</a><a class="headerlink" href="#html-output" title="Permalink to this headline">¶</a></h3>
<p>The <code class="docutils literal notranslate"><span class="pre">gcovr</span></code> command can also generate a simple
HTML output using the <code class="docutils literal notranslate"><span class="pre">--html</span></code> option:</p>
<pre class="code bash literal-block">
gcovr -r . --html -o example-html.html
</pre>
<p>This generates a HTML summary of the lines executed.  In this
example, the file <code class="docutils literal notranslate"><span class="pre">example1.html</span></code> is generated, which has the
following output:</p>
<img alt="_images/screenshot-html.png" class="align-center" src="_images/screenshot-html.png" />
<p>The default behavior of the <code class="docutils literal notranslate"><span class="pre">--html</span></code> option is to generate HTML for
a single webpage that summarizes the coverage for all files.  The
HTML is printed to standard output, but the <code class="docutils literal notranslate"><span class="pre">-o</span></code> (<code class="docutils literal notranslate"><span class="pre">--output</span></code>) option
is used to specify a file that stores the HTML output.</p>
<p>The <code class="docutils literal notranslate"><span class="pre">--html-details</span></code> option is used to create a separate web page
for each file.  Each of these web pages includes the contents of
file with annotations that summarize code coverage.  Consider the following
command:</p>
<pre class="code bash literal-block">
gcovr -r . --html --html-details -o example-html-details.html
</pre>
<p>This generates the following HTML page for the file <code class="docutils literal notranslate"><span class="pre">example1.cpp</span></code>:</p>
<img alt="_images/screenshot-html-details.example.cpp.png" class="align-center" src="_images/screenshot-html-details.example.cpp.png" />
<p>Note that the <code class="docutils literal notranslate"><span class="pre">--html-details</span></code> option can only be used with the
<code class="docutils literal notranslate"><span class="pre">-o</span></code> (<code class="docutils literal notranslate"><span class="pre">--output</span></code>) option.  For example, if the <code class="docutils literal notranslate"><span class="pre">--output</span></code> option
specifies the output file <code class="docutils literal notranslate"><span class="pre">coverage.html</span></code>, then the web pages
generated for each file will have names of the form
<code class="docutils literal notranslate"><span class="pre">coverage.&lt;filename&gt;.html</span></code>.</p>
</div>
</div>
<div class="section" id="the-gcovr-command">
<h2><a class="toc-backref" href="#id6">The gcovr Command</a><a class="headerlink" href="#the-gcovr-command" title="Permalink to this headline">¶</a></h2>
<p>The <code class="docutils literal notranslate"><span class="pre">gcovr</span></code> command recursively searches a directory tree to find
<code class="docutils literal notranslate"><span class="pre">gcov</span></code> coverage files, and generates a text summary of the code
coverage.  The <code class="docutils literal notranslate"><span class="pre">--help</span></code> option generates the following summary of
the <code class="docutils literal notranslate"><span class="pre">gcovr</span></code> command line options:</p>
<div class="section" id="gcovr">
<h3><a class="toc-backref" href="#id7">gcovr</a><a class="headerlink" href="#gcovr" title="Permalink to this headline">¶</a></h3>
<p>A utility to run gcov and summarize the coverage in simple reports.</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="go">usage: gcovr [options] [search_paths...]</span>
</pre></div>
</div>
<p>See &lt;<a class="reference external" href="http://gcovr.com/">http://gcovr.com/</a>&gt; for the full manual.</p>
<div class="section" id="options">
<h4>Options<a class="headerlink" href="#options" title="Permalink to this headline">¶</a></h4>
<dl class="option">
<dt id="cmdoption-gcovr-arg-search-paths">
<code class="descname">search_paths</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-arg-search-paths" title="Permalink to this definition">¶</a></dt>
<dd><p>Search these directories for coverage files. Defaults to --root and --object-directory.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-h">
<code class="descname">-h</code><code class="descclassname"></code><code class="descclassname">, </code><code class="descname">--help</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-h" title="Permalink to this definition">¶</a></dt>
<dd><p>Show this help message, then exit.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-version">
<code class="descname">--version</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-version" title="Permalink to this definition">¶</a></dt>
<dd><p>Print the version number, then exit.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-v">
<code class="descname">-v</code><code class="descclassname"></code><code class="descclassname">, </code><code class="descname">--verbose</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-v" title="Permalink to this definition">¶</a></dt>
<dd><p>Print progress messages. Please include this output in bug reports.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-r">
<code class="descname">-r</code><code class="descclassname"> &lt;root&gt;</code><code class="descclassname">, </code><code class="descname">--root</code><code class="descclassname"> &lt;root&gt;</code><a class="headerlink" href="#cmdoption-gcovr-r" title="Permalink to this definition">¶</a></dt>
<dd><p>The root directory of your source files. Defaults to ‘.’, the current directory. File names are reported relative to this root. The --root is the default --filter.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-fail-under-line">
<code class="descname">--fail-under-line</code><code class="descclassname"> &lt;min&gt;</code><a class="headerlink" href="#cmdoption-gcovr-fail-under-line" title="Permalink to this definition">¶</a></dt>
<dd><p>Exit with a status of 2 if the total line coverage is less than MIN. Can be ORed with exit status of ‘--fail-under-branch’ option.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-fail-under-branch">
<code class="descname">--fail-under-branch</code><code class="descclassname"> &lt;min&gt;</code><a class="headerlink" href="#cmdoption-gcovr-fail-under-branch" title="Permalink to this definition">¶</a></dt>
<dd><p>Exit with a status of 4 if the total branch coverage is less than MIN. Can be ORed with exit status of ‘--fail-under-line’ option.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-source-encoding">
<code class="descname">--source-encoding</code><code class="descclassname"> &lt;source_encoding&gt;</code><a class="headerlink" href="#cmdoption-gcovr-source-encoding" title="Permalink to this definition">¶</a></dt>
<dd><p>Select the source file encoding. Defaults to the system default encoding (UTF-8).</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-html-medium-threshold">
<code class="descname">--html-medium-threshold</code><code class="descclassname"> &lt;medium&gt;</code><a class="headerlink" href="#cmdoption-gcovr-html-medium-threshold" title="Permalink to this definition">¶</a></dt>
<dd><p>If the coverage is below MEDIUM, the value is marked as low coverage in the HTML report. MEDIUM has to be lower than or equal to value of --html-high-threshold. If MEDIUM is equal to value of --html-high-threshold the report has only high and low coverage. Default is 75.0.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-html-high-threshold">
<code class="descname">--html-high-threshold</code><code class="descclassname"> &lt;high&gt;</code><a class="headerlink" href="#cmdoption-gcovr-html-high-threshold" title="Permalink to this definition">¶</a></dt>
<dd><p>If the coverage is below HIGH, the value is marked as medium coverage in the HTML report. HIGH has to be greater than or equal to value of --html-medium-threshold. If HIGH is equal to value of --html-medium-threshold the report has only high and low coverage. Default is 90.0.</p>
</dd></dl>

</div>
<div class="section" id="output-options">
<h4>Output Options<a class="headerlink" href="#output-options" title="Permalink to this headline">¶</a></h4>
<p>Gcovr prints a text report by default, but can switch to XML or HTML.</p>
<dl class="option">
<dt id="cmdoption-gcovr-o">
<code class="descname">-o</code><code class="descclassname"> &lt;output&gt;</code><code class="descclassname">, </code><code class="descname">--output</code><code class="descclassname"> &lt;output&gt;</code><a class="headerlink" href="#cmdoption-gcovr-o" title="Permalink to this definition">¶</a></dt>
<dd><p>Print output to this filename. Defaults to stdout. Required for --html-details.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-b">
<code class="descname">-b</code><code class="descclassname"></code><code class="descclassname">, </code><code class="descname">--branches</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-b" title="Permalink to this definition">¶</a></dt>
<dd><p>Report the branch coverage instead of the line coverage. For text report only.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-u">
<code class="descname">-u</code><code class="descclassname"></code><code class="descclassname">, </code><code class="descname">--sort-uncovered</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-u" title="Permalink to this definition">¶</a></dt>
<dd><p>Sort entries by increasing number of uncovered lines. For text and HTML report.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-p">
<code class="descname">-p</code><code class="descclassname"></code><code class="descclassname">, </code><code class="descname">--sort-percentage</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-p" title="Permalink to this definition">¶</a></dt>
<dd><p>Sort entries by increasing percentage of uncovered lines. For text and HTML report.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-x">
<code class="descname">-x</code><code class="descclassname"></code><code class="descclassname">, </code><code class="descname">--xml</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-x" title="Permalink to this definition">¶</a></dt>
<dd><p>Generate a Cobertura XML report.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-xml-pretty">
<code class="descname">--xml-pretty</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-xml-pretty" title="Permalink to this definition">¶</a></dt>
<dd><p>Pretty-print the XML report. Implies --xml. Default: False.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-html">
<code class="descname">--html</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-html" title="Permalink to this definition">¶</a></dt>
<dd><p>Generate a HTML report.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-html-details">
<code class="descname">--html-details</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-html-details" title="Permalink to this definition">¶</a></dt>
<dd><p>Add annotated source code reports to the HTML report. Requires --output as a basename for the reports. Implies --html.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-html-title">
<code class="descname">--html-title</code><code class="descclassname"> &lt;title&gt;</code><a class="headerlink" href="#cmdoption-gcovr-html-title" title="Permalink to this definition">¶</a></dt>
<dd><p>Use TITLE as title for the HTML report. Default is Head.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-html-absolute-paths">
<code class="descname">--html-absolute-paths</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-html-absolute-paths" title="Permalink to this definition">¶</a></dt>
<dd><p>Use absolute paths to link the --html-details reports. Defaults to relative links.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-html-encoding">
<code class="descname">--html-encoding</code><code class="descclassname"> &lt;html_encoding&gt;</code><a class="headerlink" href="#cmdoption-gcovr-html-encoding" title="Permalink to this definition">¶</a></dt>
<dd><p>Override the declared HTML report encoding. Defaults to UTF-8. See also --source-encoding.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-s">
<code class="descname">-s</code><code class="descclassname"></code><code class="descclassname">, </code><code class="descname">--print-summary</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-s" title="Permalink to this definition">¶</a></dt>
<dd><p>Print a small report to stdout with line &amp; branch percentage coverage. This is in addition to other reports. Default: False.</p>
</dd></dl>

</div>
<div class="section" id="filter-options">
<h4>Filter Options<a class="headerlink" href="#filter-options" title="Permalink to this headline">¶</a></h4>
<p>Filters decide which files are included in the report. Any filter must match, and no exclude filter must match. A filter is a regular expression that matches a path. Filter paths use forward slashes, even on Windows.</p>
<dl class="option">
<dt id="cmdoption-gcovr-f">
<code class="descname">-f</code><code class="descclassname"> &lt;filter&gt;</code><code class="descclassname">, </code><code class="descname">--filter</code><code class="descclassname"> &lt;filter&gt;</code><a class="headerlink" href="#cmdoption-gcovr-f" title="Permalink to this definition">¶</a></dt>
<dd><p>Keep only source files that match this filter. Can be specified multiple times. If no filters are provided, defaults to --root.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-e">
<code class="descname">-e</code><code class="descclassname"> &lt;exclude&gt;</code><code class="descclassname">, </code><code class="descname">--exclude</code><code class="descclassname"> &lt;exclude&gt;</code><a class="headerlink" href="#cmdoption-gcovr-e" title="Permalink to this definition">¶</a></dt>
<dd><p>Exclude source files that match this filter. Can be specified multiple times.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-gcov-filter">
<code class="descname">--gcov-filter</code><code class="descclassname"> &lt;gcov_filter&gt;</code><a class="headerlink" href="#cmdoption-gcovr-gcov-filter" title="Permalink to this definition">¶</a></dt>
<dd><p>Keep only gcov data files that match this filter. Can be specified multiple times.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-gcov-exclude">
<code class="descname">--gcov-exclude</code><code class="descclassname"> &lt;gcov_exclude&gt;</code><a class="headerlink" href="#cmdoption-gcovr-gcov-exclude" title="Permalink to this definition">¶</a></dt>
<dd><p>Exclude gcov data files that match this filter. Can be specified multiple times.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-exclude-directories">
<code class="descname">--exclude-directories</code><code class="descclassname"> &lt;exclude_dirs&gt;</code><a class="headerlink" href="#cmdoption-gcovr-exclude-directories" title="Permalink to this definition">¶</a></dt>
<dd><p>Exclude directories that match this regex while searching raw coverage files. Can be specified multiple times.</p>
</dd></dl>

</div>
<div class="section" id="gcov-options">
<h4>GCOV Options<a class="headerlink" href="#gcov-options" title="Permalink to this headline">¶</a></h4>
<p>The ‘gcov’ tool turns raw coverage files (.gcda and .gcno) into .gcov files that are then processed by gcovr. The gcno files are generated by the compiler. The gcda files are generated when the instrumented program is executed.</p>
<dl class="option">
<dt id="cmdoption-gcovr-gcov-executable">
<code class="descname">--gcov-executable</code><code class="descclassname"> &lt;gcov_cmd&gt;</code><a class="headerlink" href="#cmdoption-gcovr-gcov-executable" title="Permalink to this definition">¶</a></dt>
<dd><p>Use a particular gcov executable. Must match the compiler you are using, e.g. ‘llvm-cov gcov’ for Clang. Can include additional arguments. Defaults to the GCOV environment variable, or ‘gcov’: ‘gcov’.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-exclude-unreachable-branches">
<code class="descname">--exclude-unreachable-branches</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-exclude-unreachable-branches" title="Permalink to this definition">¶</a></dt>
<dd><p>Exclude branch coverage with LCOV/GCOV exclude markers. Additionally, exclude branch coverage from lines without useful source code (often, compiler-generated “dead” code). Default: False.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-g">
<code class="descname">-g</code><code class="descclassname"></code><code class="descclassname">, </code><code class="descname">--use-gcov-files</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-g" title="Permalink to this definition">¶</a></dt>
<dd><p>Use existing gcov files for analysis. Default: False.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-gcov-ignore-parse-errors">
<code class="descname">--gcov-ignore-parse-errors</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-gcov-ignore-parse-errors" title="Permalink to this definition">¶</a></dt>
<dd><p>Skip lines with parse errors in GCOV files instead of exiting with an error. A report will be shown on stderr. Default: False.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-object-directory">
<code class="descname">--object-directory</code><code class="descclassname"> &lt;objdir&gt;</code><a class="headerlink" href="#cmdoption-gcovr-object-directory" title="Permalink to this definition">¶</a></dt>
<dd><p>Override normal working directory detection. Gcovr needs to identify the path between gcda files and the directory where the compiler was originally run. Normally, gcovr can guess correctly. This option specifies either the path from gcc to the gcda file (i.e. gcc’s ‘-o’ option), or the path from the gcda file to gcc’s working directory.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-k">
<code class="descname">-k</code><code class="descclassname"></code><code class="descclassname">, </code><code class="descname">--keep</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-k" title="Permalink to this definition">¶</a></dt>
<dd><p>Keep gcov files after processing. This applies both to files that were generated by gcovr, or were supplied via the --use-gcov-files option. Default: False.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-d">
<code class="descname">-d</code><code class="descclassname"></code><code class="descclassname">, </code><code class="descname">--delete</code><code class="descclassname"></code><a class="headerlink" href="#cmdoption-gcovr-d" title="Permalink to this definition">¶</a></dt>
<dd><p>Delete gcda files after processing. Default: False.</p>
</dd></dl>

<dl class="option">
<dt id="cmdoption-gcovr-j">
<code class="descname">-j</code><code class="descclassname"> &lt;gcov_parallel&gt;</code><a class="headerlink" href="#cmdoption-gcovr-j" title="Permalink to this definition">¶</a></dt>
<dd><p>Set the number of threads to use in parallel.</p>
</dd></dl>

</div>
</div>
<p>The above <a class="reference internal" href="#getting-started">Getting Started</a> guide
illustrates the use of some command line options.
<a class="reference internal" href="#using-filters">Using Filters</a> is discussed below.</p>
</div>
<div class="section" id="using-filters">
<h2><a class="toc-backref" href="#id8">Using Filters</a><a class="headerlink" href="#using-filters" title="Permalink to this headline">¶</a></h2>
<p>Gcovr tries to only report coverage for files within your project,
not for your libraries. This is influenced by the following options:</p>
<ul class="simple">
<li><a class="reference internal" href="#cmdoption-gcovr-r"><code class="xref std std-option docutils literal notranslate"><span class="pre">-r</span></code></a>, <a class="reference internal" href="#cmdoption-gcovr-r"><code class="xref std std-option docutils literal notranslate"><span class="pre">--root</span></code></a></li>
<li><a class="reference internal" href="#cmdoption-gcovr-f"><code class="xref std std-option docutils literal notranslate"><span class="pre">-f</span></code></a>, <a class="reference internal" href="#cmdoption-gcovr-f"><code class="xref std std-option docutils literal notranslate"><span class="pre">--filter</span></code></a></li>
<li><a class="reference internal" href="#cmdoption-gcovr-e"><code class="xref std std-option docutils literal notranslate"><span class="pre">-e</span></code></a>, <a class="reference internal" href="#cmdoption-gcovr-e"><code class="xref std std-option docutils literal notranslate"><span class="pre">--exclude</span></code></a></li>
<li><a class="reference internal" href="#cmdoption-gcovr-gcov-filter"><code class="xref std std-option docutils literal notranslate"><span class="pre">--gcov-filter</span></code></a></li>
<li><a class="reference internal" href="#cmdoption-gcovr-gcov-exclude"><code class="xref std std-option docutils literal notranslate"><span class="pre">--gcov-exclude</span></code></a></li>
<li><a class="reference internal" href="#cmdoption-gcovr-exclude-directories"><code class="xref std std-option docutils literal notranslate"><span class="pre">--exclude-directories</span></code></a></li>
<li>(the current working directory where gcovr is invoked)</li>
</ul>
<p>These options take filters.
A filter is a regular expression that matches a file path.
Because filters are regexes,
you will have to escape “special” characters with a backslash <code class="docutils literal notranslate"><span class="pre">\</span></code>.</p>
<p>Always use forward slashes <code class="docutils literal notranslate"><span class="pre">/</span></code> as path separators, even on Windows:</p>
<ul class="simple">
<li>wrong:   <code class="docutils literal notranslate"><span class="pre">--filter</span> <span class="pre">C:\project\src\</span></code></li>
<li>correct: <code class="docutils literal notranslate"><span class="pre">--filter</span> <span class="pre">C:/project/src/</span></code></li>
</ul>
<p>If the filter looks like an absolute path,
it is matched against an absolute path.
Otherwise, the filter is matched against a relative path,
where that path is relative to the current directory.
Examples of relative filters:</p>
<ul class="simple">
<li><code class="docutils literal notranslate"><span class="pre">--filter</span> <span class="pre">subdir/</span></code> matches only that subdirectory</li>
<li><code class="docutils literal notranslate"><span class="pre">--filter</span> <span class="pre">'\.\./src/'</span></code> matches a sibling directory <code class="docutils literal notranslate"><span class="pre">../src</span></code>.
But because a dot <code class="docutils literal notranslate"><span class="pre">.</span></code> matches any character in a regex,
we have to escape it.
You have to use additional shell escaping.
This example uses single quotes for Bash or POSIX shell.</li>
<li><code class="docutils literal notranslate"><span class="pre">--filter</span> <span class="pre">'(.+/)?foo\.c$'</span></code> matches only files called <code class="docutils literal notranslate"><span class="pre">foo.c</span></code>.
The regex must match from the start of the relative path,
so we ignore any leading directory parts with <code class="docutils literal notranslate"><span class="pre">(.+/)?</span></code>.
The <code class="docutils literal notranslate"><span class="pre">$</span></code> at the end ensures that the path ends here.</li>
</ul>
<p>If no <a class="reference internal" href="#cmdoption-gcovr-f"><code class="xref std std-option docutils literal notranslate"><span class="pre">--filter</span></code></a> is provided,
the <a class="reference internal" href="#cmdoption-gcovr-r"><code class="xref std std-option docutils literal notranslate"><span class="pre">--root</span></code></a> is turned into a default filter.
Therefore, files outside of the <a class="reference internal" href="#cmdoption-gcovr-r"><code class="xref std std-option docutils literal notranslate"><span class="pre">--root</span></code></a> directory are excluded.</p>
<p>To be included in a report, the source file must match any <a class="reference internal" href="#cmdoption-gcovr-f"><code class="xref std std-option docutils literal notranslate"><span class="pre">--filter</span></code></a>,
and must not match any <a class="reference internal" href="#cmdoption-gcovr-e"><code class="xref std std-option docutils literal notranslate"><span class="pre">--exclude</span></code></a> filter.</p>
<p>The <a class="reference internal" href="#cmdoption-gcovr-gcov-filter"><code class="xref std std-option docutils literal notranslate"><span class="pre">--gcov-filter</span></code></a> and <a class="reference internal" href="#cmdoption-gcovr-gcov-exclude"><code class="xref std std-option docutils literal notranslate"><span class="pre">--gcov-exclude</span></code></a> filters apply to the <code class="docutils literal notranslate"><span class="pre">.gcov</span></code> files created by <code class="docutils literal notranslate"><span class="pre">gcov</span></code>.
This is useful mostly when running gcov yourself,
and then invoking gcovr with <a class="reference internal" href="#cmdoption-gcovr-g"><code class="xref std std-option docutils literal notranslate"><span class="pre">-g</span></code></a>/<a class="reference internal" href="#cmdoption-gcovr-g"><code class="xref std std-option docutils literal notranslate"><span class="pre">--use-gcov-files</span></code></a>.
But these filters also apply when gcov is launched by gcovr.</p>
<div class="section" id="speeding-up-coverage-data-search">
<h3><a class="toc-backref" href="#id9">Speeding up coverage data search</a><a class="headerlink" href="#speeding-up-coverage-data-search" title="Permalink to this headline">¶</a></h3>
<p>The <a class="reference internal" href="#cmdoption-gcovr-exclude-directories"><code class="xref std std-option docutils literal notranslate"><span class="pre">--exclude-directories</span></code></a> filter is used
while searching for raw coverage data
(or for existing <code class="docutils literal notranslate"><span class="pre">.gcov</span></code> files when <a class="reference internal" href="#cmdoption-gcovr-g"><code class="xref std std-option docutils literal notranslate"><span class="pre">--use-gcov-files</span></code></a> is active).
This filter is matched against directory paths, not file paths.
If a directory matches,
all its contents (files and subdirectories) will be excluded from the search.
For example, consider this build directory:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>build/
├─ main.o
├─ main.gcda
├─ main.gcno
├─ a/
│  ├─ awesome_code.o
│  ├─ awesome_code.gcda
│  └─ awesome_code.gcno
└─ b/
   ├─ better_code.o
   ├─ better_code.gcda
   └─ better_code.gcno
</pre></div>
</div>
<p>If we run <code class="docutils literal notranslate"><span class="pre">gcovr</span> <span class="pre">--exclude-directories</span> <span class="pre">'build/a$'</span></code>,
this will exclude anything in the <code class="docutils literal notranslate"><span class="pre">build/a</span></code> directory
but will use the coverage data for <code class="docutils literal notranslate"><span class="pre">better_code.o</span></code> and <code class="docutils literal notranslate"><span class="pre">main.o</span></code>.</p>
<p>This can speed up gcovr when you have a complicated build directory structure.
Consider also using the <a class="reference internal" href="#cmdoption-gcovr-arg-search-paths"><code class="xref std std-option docutils literal notranslate"><span class="pre">search_paths</span></code></a>
or <a class="reference internal" href="#cmdoption-gcovr-object-directory"><code class="xref std std-option docutils literal notranslate"><span class="pre">--object-directory</span></code></a> arguments
to specify where gcovr starts searching.
If you are unsure which directories are being searched,
run gcovr in <a class="reference internal" href="#cmdoption-gcovr-v"><code class="xref std std-option docutils literal notranslate"><span class="pre">--verbose</span></code></a> mode.</p>
<p>For each found coverage data file gcovr will invoke the <code class="docutils literal notranslate"><span class="pre">gcov</span></code> tool.
This is typically the slowest part,
and other filters can only be applied <em>after</em> this step.
In some cases, parallel execution with the <a class="reference internal" href="#cmdoption-gcovr-j"><code class="xref std std-option docutils literal notranslate"><span class="pre">-j</span></code></a> option
might be helpful to speed up processing.</p>
</div>
<div class="section" id="filters-for-symlinks">
<h3><a class="toc-backref" href="#id10">Filters for symlinks</a><a class="headerlink" href="#filters-for-symlinks" title="Permalink to this headline">¶</a></h3>
<p>Gcovr matches filters against <em>real paths</em>
that have all their symlinks resolved.
E.g. consider this project layout:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span>/home/you/
├─ project/  (pwd)
│  ├─ src/
│  ├─ relevant-library/ -&gt; ../external-library/
│  └─ ignore-this/
└─ external-library/
   └─ src/
</pre></div>
</div>
<p>Here, the <code class="docutils literal notranslate"><span class="pre">relevant-library</span></code>
has the real path <code class="docutils literal notranslate"><span class="pre">/home/you/external-library</span></code>.</p>
<p>To write a filter that includes both <code class="docutils literal notranslate"><span class="pre">src/</span></code> and <code class="docutils literal notranslate"><span class="pre">relevant-library/src/</span></code>,
we cannot use <code class="docutils literal notranslate"><span class="pre">--filter</span> <span class="pre">relevant-library/src/</span></code>
because that contains a symlink.
Instead, we have to use an absolute path to the real name:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">gcovr</span> <span class="o">--</span><span class="nb">filter</span> <span class="n">src</span><span class="o">/</span> <span class="o">--</span><span class="nb">filter</span> <span class="o">/</span><span class="n">home</span><span class="o">/</span><span class="n">you</span><span class="o">/</span><span class="n">external</span><span class="o">-</span><span class="n">library</span><span class="o">/</span><span class="n">src</span><span class="o">/</span>
</pre></div>
</div>
<p>or a relative path to the real path:</p>
<div class="highlight-default notranslate"><div class="highlight"><pre><span></span><span class="n">gcovr</span> <span class="o">--</span><span class="nb">filter</span> <span class="n">src</span><span class="o">/</span> <span class="o">--</span><span class="nb">filter</span> <span class="s1">&#39;\.\./external-library/src/&#39;</span>
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">This section discusses symlinks on Unix systems.
The behavior under Windows is unclear.
If you have more insight,
please update this section by submitting a pull request
(see our <a class="reference internal" href="contributing.html"><span class="doc">contributing guide</span></a>).</p>
</div>
</div>
</div>
<div class="section" id="acknowledgements">
<h2><a class="toc-backref" href="#id11">Acknowledgements</a><a class="headerlink" href="#acknowledgements" title="Permalink to this headline">¶</a></h2>
<p>Gcovr is maintained by:</p>
<blockquote>
<div>William Hart,
John Siirola,
and Lukas Atkinson.</div></blockquote>
<p>The following developers contributed to gcovr (ordered alphabetically):</p>
<blockquote>
<div>Andrew Stone,
Arvin Schnell,
Attie Grande,
Bernhard Breinbauer,
Carlos Jenkins,
Christian Taedcke,
Dave George,
Dom Postorivo,
goriy,
ja11sop,
James Reynolds,
Jessica Levine,
Joel Klinghed,
John Siirola,
Jörg Kreuzberger,
Kai Blaschke,
Kevin Cai,
libPhipp,
Lukas Atkinson,
Luke Woydziak,
Marek Kurdej,
Martin Mraz,
Matsumoto Taichi,
Matthew Stadelman,
Matthias Schmieder,
Matthieu Darbois,
Michał Pszona,
Michael Förderer,
Mikael Salson,
Mikk Leini,
Nikolaj Schumacher,
Piotr Dziwinski,
Reto Schneider,
Robert Rosengren,
Songmin Li,
Steven Myint,
Sylvestre Ledru,
trapzero,
William Hart,
and possibly others.</div></blockquote>
<p>The development of Gcovr has been partially supported
by Sandia National Laboratories.  Sandia National Laboratories is
a multi-program laboratory managed and operated by Sandia Corporation,
a wholly owned subsidiary of Lockheed Martin Corporation, for the
U.S.  Department of Energy’s National Nuclear Security Administration
under contract DE-AC04-94AL85000.</p>
</div>
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