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core/com.nokia.carbide.cpp.compiler.doc.user/html/errors/err_suspicious_assgn.htm
author fturovic <frank.turovich@nokia.com>
Mon, 19 Jul 2010 16:13:24 -0500
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN"><html>
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<head>
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<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1" />
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<meta http-equiv="Content-Style-Type" content="text/css" />
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<meta name="LASTUPDATED" content="06/17/05 11:09:43" />
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<title>Suspicious Assignments and Incorrect Function Returns</title>
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<link rel="StyleSheet" href="../../book.css" type="text/css"/>
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</head>
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<body bgcolor="#FFFFFF">
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<h3>Suspicious Assignments and Incorrect Function Returns</h3>
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<p>  If you enable the Extended Error Checking setting, the C compiler generates a warning if it encounters one of the following potential problems:</p>
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<ul>
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  <li>A non-void function that does not contain a return statement. For example, the source code in Listing 1 generates a warning.</li>
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</ul>
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<blockquote>
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  <div class="listing">
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    <p>Listing 1. Non-void Function with no return Statement</p>
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    <p>main() /* assumed to return int */<br />
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      {<br />
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      printf (&quot;hello world\n&quot;);<br />
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      } /* WARNING: no return statement */<br />
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      Listing 6.8 does not generate a warning.<br />
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      Listing 6.8 Explicitly Specifying a Function&rsquo;s void Return Type<br />
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      void main() /* function declared to return void */<br />
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      {<br />
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      printf (&quot;hello world\n&quot;);<br />
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      }<br />
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    </p>
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  </div>
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</blockquote>
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<ul>
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  <li>An integer or floating-point value assigned to an enum type. Listing 2 shows an example.
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  </li>
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</ul>
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<blockquote>
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  <div class="listing">
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    <h5>Listing 2. Assigning to an Enumerated Type</h5>
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    <p>enum Day { Sunday, Monday, Tuesday, Wednesday, <br />
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      Thursday, Friday, Saturday } d;</p>
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    <p>d = 5; /* WARNING */<br />
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      d = Monday; /* OK */<br />
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      d = (Day)3 ; /* OK */<br />
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&bull; An empty return statement in a function that is not declared void. For example, the following code results in a warning:<br />
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      int MyInit(void)<br />
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      {<br />
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      int err = GetMyResources();<br />
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      if (err!=0) return; /* ERROR: Empty return statement */</p>
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    <p> /* ... */<br />
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      This is OK:<br />
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      int MyInit(void)<br />
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      {<br />
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      int err = GetMyResources();<br />
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      if (err!=0) return -1; /* OK */</p>
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    <p> /* ... */</p>
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  </div>
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</blockquote>
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<p> The Extended Error Checking setting corresponds to the pragma <span class="code">extended_errorcheck</span>, described at <a href="../pragmas/p_extended_errorcheck.htm">extended_errorcheck</a>. To check this setting, use <span class="code">__option (extended_errorcheck)</span>.</p>
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<p> See <a href="../symbols/sym_settings.htm">Checking Option Settings</a> for information on how to use this directive.<br />
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</p>
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<div id="footer">Copyright &copy; 2010 Nokia Corporation and/or its subsidiary(-ies). All rights reserved. <br>License: <a href="http://www.eclipse.org/legal/epl-v10.html">http://www.eclipse.org/legal/epl-v10.html</a></div>
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FCL/sftools/dev/ide/carbidecpp