QA·C Help - 2811

	2811	Definite: Dereference of NULL pointer.

NULL pointers

A definite anomaly has been detected. Examination of the context indicates that this expression will always result in the dereferencing of a null pointer. The result of any attempt to dereference a null pointer value is undefined.

In the example below, p is NULL throughout the code contained in the "if" block and the result of the dereferencing operation will always be undefined.


/*PRQA S 504,2017,2983,2986,3199,3203,3227,3408,3412,3673,4600 ++*/
#define NULL (void *)0

void foo(int *p)
{
    int r;

    if (p == NULL)
    {
        r = *p;             /* 2811 */
    }
}

MISRA C:2012 Rules applicable to message 2811:

Dir-4.1 (Required)

Run-time failures shall be minimized

See also:

2810 Constant: Dereference of NULL pointer.
2812 Apparent: Dereference of NULL pointer.
2813 Suspicious: Dereference of NULL pointer.
2814 Possible: Dereference of NULL pointer.
2820 Constant: Arithmetic operation on NULL pointer.
2821 Definite: Arithmetic operation on NULL pointer.
2822 Apparent: Arithmetic operation on NULL pointer.
2823 Suspicious: Arithmetic operation on NULL pointer.
2824 Possible: Arithmetic operation on NULL pointer.

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MISRA C:2012 Compliance Module 1.0
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