<!DOCTYPE qhelp PUBLIC

"-//Semmle//qhelp//EN"

"qhelp.dtd">

<qhelp>

<overview>

<p>A function is called without a prior function declaration or definition.

When this happens, the compiler generates an implicit declaration of the function,

specifying an integer return type and no parameters.</p>

</p>

<p>This may indicate a misspelled function name, or that the required header containing

the function declaration has not been included.</p>

</overview>

<recommendation>

<p>Ensure that the called function has been declared previously in the file or an included header file.</p>

</recommendation>

<example><sample src="ImplicitFunctionDeclaration.c" />

</example>

<references>

<li>SEI CERT C Coding Standard: <a href="https://wiki.sei.cmu.edu/confluence/display/c/DCL31-C.+Declare+identifiers+before+using+them"> DCL20-C. Explicitly specify void when a function accepts no arguments </a></li>

</references>

</qhelp>