UnmanagedCodeCheck.qhelp

<!DOCTYPE qhelp PUBLIC
  "-//Semmle//qhelp//EN"
  "qhelp.dtd">
<qhelp>
<overview>
<p>Microsoft defines two broad categories for source code. Managed code compiles into bytecode and is then executed by a virtual 
machine. Unmanaged code is compiled directly into machine code. All C# code is managed but it is possible to call external unmanaged 
code. This rule finds <code>extern</code> methods that are implemented by unmanaged code. Managed code has many advantages over 
unmanaged code such as built in memory management performed by the virtual machine and the ability to run compiled programs 
on a wider variety of architectures.</p>

</overview>
<recommendation>
<p>Consider whether the unmanaged <code>extern</code> methods could be implemented in C# instead.</p>

</recommendation>
<example>
<p>This example shows a function that displays a message box when clicked. The unmanaged code is shown first and then the 
same function being performed by managed code is shown after.</p>
<sample src="UnmanagedCodeCheck.cs" />

</example>
<references>

  <li>MSDN, C# Reference <a href="http://msdn.microsoft.com/en-us/library/e59b22c5(v=vs.80).aspx">extern</a>.</li>
  <li>Wikipedia, <a href="http://en.wikipedia.org/wiki/Managed_code">Managed code</a>.</li>

</references>
</qhelp>