-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathcookbook.html
274 lines (149 loc) · 8.4 KB
/
cookbook.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
<!DOCTYPE html>
<!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
<!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Gcovr Cookbook — gcovr 4.1 documentation</title>
<link rel="stylesheet" href="_static/css/theme.css" type="text/css" />
<link rel="stylesheet" href="_static/pygments.css" type="text/css" />
<link rel="index" title="Index" href="genindex.html" />
<link rel="search" title="Search" href="search.html" />
<link rel="next" title="Frequently Asked Questions" href="faq.html" />
<link rel="prev" title="Gcovr User Guide" href="guide.html" />
<script src="_static/js/modernizr.min.js"></script>
</head>
<body class="wy-body-for-nav">
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
<div class="wy-side-scroll">
<div class="wy-side-nav-search">
<a href="index.html" class="icon icon-home"> gcovr
</a>
<div class="version">
4.1
</div>
<div role="search">
<form id="rtd-search-form" class="wy-form" action="search.html" method="get">
<input type="text" name="q" placeholder="Search docs" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
</div>
<div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
<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"><a class="reference internal" href="guide.html">Gcovr User Guide</a></li>
<li class="toctree-l1 current"><a class="current reference internal" href="#">Gcovr Cookbook</a><ul>
<li class="toctree-l2"><a class="reference internal" href="#how-to-collect-coverage-for-c-extensions-in-python">How to collect coverage for C extensions in Python</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="faq.html">Frequently Asked Questions</a></li>
<li class="toctree-l1"><a class="reference internal" href="contributing.html">Contributing</a></li>
<li class="toctree-l1"><a class="reference internal" href="changelog.html">Change Log</a></li>
<li class="toctree-l1"><a class="reference internal" href="license.html">License</a></li>
</ul>
</div>
</div>
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
<nav class="wy-nav-top" aria-label="top navigation">
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="index.html">gcovr</a>
</nav>
<div class="wy-nav-content">
<div class="rst-content">
<div role="navigation" aria-label="breadcrumbs navigation">
<ul class="wy-breadcrumbs">
<li><a href="index.html">Docs</a> »</li>
<li>Gcovr Cookbook</li>
<li class="wy-breadcrumbs-aside">
<a href="_sources/cookbook.rst.txt" rel="nofollow"> View page source</a>
</li>
</ul>
<hr/>
</div>
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
<div itemprop="articleBody">
<div class="section" id="gcovr-cookbook">
<h1>Gcovr Cookbook<a class="headerlink" href="#gcovr-cookbook" title="Permalink to this headline">¶</a></h1>
<div class="section" id="how-to-collect-coverage-for-c-extensions-in-python">
<h2>How to collect coverage for C extensions in Python<a class="headerlink" href="#how-to-collect-coverage-for-c-extensions-in-python" title="Permalink to this headline">¶</a></h2>
<p>Collecting code coverage data on the C code that makes up a Python
extension module is not quite as straightforward as with a regular C
program.</p>
<p>As with a normal C project,
we have to compile our code with coverage instrumentation.
Here, we <code class="docutils literal notranslate"><span class="pre">export</span> <span class="pre">CFLAGS="--coverage"</span></code>
and then run <code class="docutils literal notranslate"><span class="pre">python3</span> <span class="pre">setup.py</span> <span class="pre">build_ext</span></code>.</p>
<p>Unfortunately, <code class="docutils literal notranslate"><span class="pre">build_ext</span></code> can rebuild a source file
even if the current object file is up to date.
If multiple extension modules share the same source code file,
gcov will get confused by the different timestamps
and report inaccurate coverage.
It is nontrivial to adapt the <code class="docutils literal notranslate"><span class="pre">build_ext</span></code> process to avoid this.</p>
<p>Instead, we can use the <code class="docutils literal notranslate"><span class="pre">ccache</span></code> utility to make the compilation lazy
(works best on Unix systems).
Before we invoke the <code class="docutils literal notranslate"><span class="pre">build_ext</span></code> step, we first <code class="docutils literal notranslate"><span class="pre">export</span> <span class="pre">CC="ccache</span> <span class="pre">gcc"</span></code>.
Ccache works well but isn’t absolutely perfect,
see the <a class="reference external" href="https://ccache.samba.org/manual/latest.html#_caveats">ccache manual</a> for caveats.</p>
<p>A shell session might look like this:</p>
<div class="highlight-sh notranslate"><div class="highlight"><pre><span></span><span class="c1"># Set required env vars</span>
<span class="nb">export</span> <span class="nv">CFLAGS</span><span class="o">=</span><span class="s2">"--coverage"</span>
<span class="nb">export</span> <span class="nv">CC</span><span class="o">=</span><span class="s2">"ccache gcc"</span>
<span class="c1"># clear out build files so we get a fresh compile</span>
rm -rf build/temp.* <span class="c1"># contains old .gcda, .gcno files</span>
rm -rf build/lib.*
<span class="c1"># rebuild extensions</span>
python3 setup.py build_ext --inplace <span class="c1"># possibly --force</span>
<span class="c1"># run test command i.e. pytest</span>
<span class="c1"># run gcovr</span>
rm -rf coverage<span class="p">;</span> mkdir coverage
gcovr --filter src/ --print-summary --html-details -o coverage/index.html
</pre></div>
</div>
</div>
</div>
</div>
</div>
<footer>
<div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
<a href="faq.html" class="btn btn-neutral float-right" title="Frequently Asked Questions" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right"></span></a>
<a href="guide.html" class="btn btn-neutral" title="Gcovr User Guide" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left"></span> Previous</a>
</div>
<hr/>
<div role="contentinfo">
<p>
© Copyright 2018, the gcovr authors.
</p>
</div>
Built with <a href="http://sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/rtfd/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
</footer>
</div>
</div>
</section>
</div>
<script type="text/javascript">
var DOCUMENTATION_OPTIONS = {
URL_ROOT:'./',
VERSION:'4.1',
LANGUAGE:'None',
COLLAPSE_INDEX:false,
FILE_SUFFIX:'.html',
HAS_SOURCE: true,
SOURCELINK_SUFFIX: '.txt'
};
</script>
<script type="text/javascript" src="_static/jquery.js"></script>
<script type="text/javascript" src="_static/underscore.js"></script>
<script type="text/javascript" src="_static/doctools.js"></script>
<script type="text/javascript" src="_static/js/theme.js"></script>
<script type="text/javascript">
jQuery(function () {
SphinxRtdTheme.Navigation.enable(true);
});
</script>
</body>
</html>