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<a name="Skipping-Over-Functions-and-Files"></a>
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<hr>
<a name="Skipping-Over-Functions-and-Files-1"></a>
<h3 class="section">5.3 Skipping Over Functions and Files</h3>
<a name="index-skipping-over-functions-and-files"></a>

<p>The program you are debugging may contain some functions which are
uninteresting to debug.  The <code>skip</code> command lets you tell <small>GDB</small> to
skip a function, all functions in a file or a particular function in
a particular file when stepping.
</p>
<p>For example, consider the following C function:
</p>
<div class="smallexample">
<pre class="smallexample">101     int func()
102     {
103         foo(boring());
104         bar(boring());
105     }
</pre></div>

<p>Suppose you wish to step into the functions <code>foo</code> and <code>bar</code>, but you
are not interested in stepping through <code>boring</code>.  If you run <code>step</code>
at line 103, you&rsquo;ll enter <code>boring()</code>, but if you run <code>next</code>, you&rsquo;ll
step over both <code>foo</code> and <code>boring</code>!
</p>
<p>One solution is to <code>step</code> into <code>boring</code> and use the <code>finish</code>
command to immediately exit it.  But this can become tedious if <code>boring</code>
is called from many places.
</p>
<p>A more flexible solution is to execute <kbd>skip boring</kbd>.  This instructs
<small>GDB</small> never to step into <code>boring</code>.  Now when you execute
<code>step</code> at line 103, you&rsquo;ll step over <code>boring</code> and directly into
<code>foo</code>.
</p>
<p>Functions may be skipped by providing either a function name, linespec
(see <a href="Specify-Location.html#Specify-Location">Specify Location</a>), regular expression that matches the function&rsquo;s
name, file name or a <code>glob</code>-style pattern that matches the file name.
</p>
<p>On Posix systems the form of the regular expression is
&ldquo;Extended Regular Expressions&rdquo;.  See for example &lsquo;<samp>man 7 regex</samp>&rsquo;
on <small>GNU</small>/Linux systems.  On non-Posix systems the form of the regular
expression is whatever is provided by the <code>regcomp</code> function of
the underlying system.
See for example &lsquo;<samp>man 7 glob</samp>&rsquo; on <small>GNU</small>/Linux systems for a
description of <code>glob</code>-style patterns.
</p>
<dl compact="compact">
<dd><a name="index-skip"></a>
</dd>
<dt><code>skip <span class="roman">[</span><var>options</var><span class="roman">]</span></code></dt>
<dd><p>The basic form of the <code>skip</code> command takes zero or more options
that specify what to skip.
The <var>options</var> argument is any useful combination of the following:
</p>
<dl compact="compact">
<dt><code>-file <var>file</var></code></dt>
<dt><code>-fi <var>file</var></code></dt>
<dd><p>Functions in <var>file</var> will be skipped over when stepping.
</p>
</dd>
<dt><code>-gfile <var>file-glob-pattern</var></code></dt>
<dt><code>-gfi <var>file-glob-pattern</var></code></dt>
<dd><a name="index-skipping-over-files-via-glob_002dstyle-patterns"></a>
<p>Functions in files matching <var>file-glob-pattern</var> will be skipped
over when stepping.
</p>
<div class="smallexample">
<pre class="smallexample">(gdb) skip -gfi utils/*.c
</pre></div>

</dd>
<dt><code>-function <var>linespec</var></code></dt>
<dt><code>-fu <var>linespec</var></code></dt>
<dd><p>Functions named by <var>linespec</var> or the function containing the line
named by <var>linespec</var> will be skipped over when stepping.
See <a href="Specify-Location.html#Specify-Location">Specify Location</a>.
</p>
</dd>
<dt><code>-rfunction <var>regexp</var></code></dt>
<dt><code>-rfu <var>regexp</var></code></dt>
<dd><a name="index-skipping-over-functions-via-regular-expressions"></a>
<p>Functions whose name matches <var>regexp</var> will be skipped over when stepping.
</p>
<p>This form is useful for complex function names.
For example, there is generally no need to step into C<tt>++</tt> <code>std::string</code>
constructors or destructors.  Plus with C<tt>++</tt> templates it can be hard to
write out the full name of the function, and often it doesn&rsquo;t matter what
the template arguments are.  Specifying the function to be skipped as a
regular expression makes this easier.
</p>
<div class="smallexample">
<pre class="smallexample">(gdb) skip -rfu ^std::(allocator|basic_string)&lt;.*&gt;::~?\1 *\(
</pre></div>

<p>If you want to skip every templated C<tt>++</tt> constructor and destructor
in the <code>std</code> namespace you can do:
</p>
<div class="smallexample">
<pre class="smallexample">(gdb) skip -rfu ^std::([a-zA-z0-9_]+)&lt;.*&gt;::~?\1 *\(
</pre></div>
</dd>
</dl>

<p>If no options are specified, the function you&rsquo;re currently debugging
will be skipped.
</p>
<a name="index-skip-function"></a>
</dd>
<dt><code>skip function <span class="roman">[</span><var>linespec</var><span class="roman">]</span></code></dt>
<dd><p>After running this command, the function named by <var>linespec</var> or the
function containing the line named by <var>linespec</var> will be skipped over when
stepping.  See <a href="Specify-Location.html#Specify-Location">Specify Location</a>.
</p>
<p>If you do not specify <var>linespec</var>, the function you&rsquo;re currently debugging
will be skipped.
</p>
<p>(If you have a function called <code>file</code> that you want to skip, use
<kbd>skip function file</kbd>.)
</p>
<a name="index-skip-file"></a>
</dd>
<dt><code>skip file <span class="roman">[</span><var>filename</var><span class="roman">]</span></code></dt>
<dd><p>After running this command, any function whose source lives in <var>filename</var>
will be skipped over when stepping.
</p>
<div class="smallexample">
<pre class="smallexample">(gdb) skip file boring.c
File boring.c will be skipped when stepping.
</pre></div>

<p>If you do not specify <var>filename</var>, functions whose source lives in the file
you&rsquo;re currently debugging will be skipped.
</p></dd>
</dl>

<p>Skips can be listed, deleted, disabled, and enabled, much like breakpoints.
These are the commands for managing your list of skips:
</p>
<dl compact="compact">
<dd><a name="index-info-skip"></a>
</dd>
<dt><code>info skip <span class="roman">[</span><var>range</var><span class="roman">]</span></code></dt>
<dd><p>Print details about the specified skip(s).  If <var>range</var> is not specified,
print a table with details about all functions and files marked for skipping.
<code>info skip</code> prints the following information about each skip:
</p>
<dl compact="compact">
<dt><em>Identifier</em></dt>
<dd><p>A number identifying this skip.
</p></dd>
<dt><em>Enabled or Disabled</em></dt>
<dd><p>Enabled skips are marked with &lsquo;<samp>y</samp>&rsquo;.
Disabled skips are marked with &lsquo;<samp>n</samp>&rsquo;.
</p></dd>
<dt><em>Glob</em></dt>
<dd><p>If the file name is a &lsquo;<samp>glob</samp>&rsquo; pattern this is &lsquo;<samp>y</samp>&rsquo;.
Otherwise it is &lsquo;<samp>n</samp>&rsquo;.
</p></dd>
<dt><em>File</em></dt>
<dd><p>The name or &lsquo;<samp>glob</samp>&rsquo; pattern of the file to be skipped.
If no file is specified this is &lsquo;<samp>&lt;none&gt;</samp>&rsquo;.
</p></dd>
<dt><em>RE</em></dt>
<dd><p>If the function name is a &lsquo;<samp>regular expression</samp>&rsquo; this is &lsquo;<samp>y</samp>&rsquo;.
Otherwise it is &lsquo;<samp>n</samp>&rsquo;.
</p></dd>
<dt><em>Function</em></dt>
<dd><p>The name or regular expression of the function to skip.
If no function is specified this is &lsquo;<samp>&lt;none&gt;</samp>&rsquo;.
</p></dd>
</dl>

<a name="index-skip-delete"></a>
</dd>
<dt><code>skip delete <span class="roman">[</span><var>range</var><span class="roman">]</span></code></dt>
<dd><p>Delete the specified skip(s).  If <var>range</var> is not specified, delete all
skips.
</p>
<a name="index-skip-enable"></a>
</dd>
<dt><code>skip enable <span class="roman">[</span><var>range</var><span class="roman">]</span></code></dt>
<dd><p>Enable the specified skip(s).  If <var>range</var> is not specified, enable all
skips.
</p>
<a name="index-skip-disable"></a>
</dd>
<dt><code>skip disable <span class="roman">[</span><var>range</var><span class="roman">]</span></code></dt>
<dd><p>Disable the specified skip(s).  If <var>range</var> is not specified, disable all
skips.
</p>
<a name="index-set-debug-skip"></a>
</dd>
<dt><code>set debug skip <span class="roman">[</span>on|off<span class="roman">]</span></code></dt>
<dd><p>Set whether to print the debug output about skipping files and functions.
</p>
<a name="index-show-debug-skip"></a>
</dd>
<dt><code>show debug skip</code></dt>
<dd><p>Show whether the debug output about skipping files and functions is printed.
</p>
</dd>
</dl>

<hr>
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