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<title>Using the GNU Compiler Collection (GCC): Statement Attributes</title>

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<a name="Statement-Attributes"></a>
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<a name="Statement-Attributes-1"></a>
<h3 class="section">6.36 Statement Attributes</h3>
<a name="index-Statement-Attributes"></a>

<p>GCC allows attributes to be set on null statements.  See <a href="Attribute-Syntax.html#Attribute-Syntax">Attribute Syntax</a>,
for details of the exact syntax for using attributes.  Other attributes are
available for functions (see <a href="Function-Attributes.html#Function-Attributes">Function Attributes</a>), variables
(see <a href="Variable-Attributes.html#Variable-Attributes">Variable Attributes</a>), labels (see <a href="Label-Attributes.html#Label-Attributes">Label Attributes</a>), enumerators
(see <a href="Enumerator-Attributes.html#Enumerator-Attributes">Enumerator Attributes</a>), and for types (see <a href="Type-Attributes.html#Type-Attributes">Type Attributes</a>).
</p>
<p>This example uses the <code>fallthrough</code> statement attribute to indicate that
the <samp>-Wimplicit-fallthrough</samp> warning should not be emitted:
</p>
<div class="smallexample">
<pre class="smallexample">switch (cond)
  {
  case 1:
    bar (1);
    __attribute__((fallthrough));
  case 2:
    &hellip;
  }
</pre></div>

<dl compact="compact">
<dt><code>fallthrough</code></dt>
<dd><a name="index-fallthrough-statement-attribute"></a>
<p>The <code>fallthrough</code> attribute with a null statement serves as a
fallthrough statement.  It hints to the compiler that a statement
that falls through to another case label, or user-defined label
in a switch statement is intentional and thus the
<samp>-Wimplicit-fallthrough</samp> warning must not trigger.  The
fallthrough attribute may appear at most once in each attribute
list, and may not be mixed with other attributes.  It can only
be used in a switch statement (the compiler will issue an error
otherwise), after a preceding statement and before a logically
succeeding case label, or user-defined label.
</p>
</dd>
</dl>


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