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<html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=ANSI_X3.4-1968" /><title>snd_BUG_ON()</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /><link rel="home" href="index.html" title="Writing an ALSA Driver" /><link rel="up" href="ch16.html" title="Chapter 16. Useful Functions" /><link rel="prev" href="ch16s02.html" title="snd_BUG()" /><link rel="next" href="ch17.html" title="Chapter 17. Acknowledgments" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center"><code class="function">snd_BUG_ON()</code></th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ch16s02.html">Prev</a> </td><th width="60%" align="center">Chapter 16. Useful Functions</th><td width="20%" align="right"> <a accesskey="n" href="ch17.html">Next</a></td></tr></table><hr /></div><div class="section" title="snd_BUG_ON()"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="useful-functions-snd-bug-on"></a><code class="function">snd_BUG_ON()</code></h2></div></div></div><p>
<code class="function">snd_BUG_ON()</code> macro is similar with
<code class="function">WARN_ON()</code> macro. For example,
</p><div class="informalexample"><pre class="programlisting">
snd_BUG_ON(!pointer);
</pre></div><p>
or it can be used as the condition,
</p><div class="informalexample"><pre class="programlisting">
if (snd_BUG_ON(non_zero_is_bug))
return -EINVAL;
</pre></div><p>
</p><p>
The macro takes an conditional expression to evaluate.
When <code class="constant">CONFIG_SND_DEBUG</code>, is set, the
expression is actually evaluated. If it's non-zero, it shows
the warning message such as
<code class="computeroutput">BUG? (xxx)</code>
normally followed by stack trace. It returns the evaluated
value.
When no <code class="constant">CONFIG_SND_DEBUG</code> is set, this
macro always returns zero.
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