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This recommendation is related to MSC07-A. Detect and remove dead code.

Non-Compliant Code Example (

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Assignment)

In this example, the comparison of a to b has no effect.

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This is likely a case of the programmer mistakenly using the equals operator == instead of the assignment operator =.

Compliant Solution (

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Assignment)

The assignment of b to a is now properly performed.

int a;
int b;
/* ... */
a = b;

Non-Compliant Code Example (

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Dereference)

In this example, p is incremented and then dereferenced. However, *p has no effect.

int *p;
/* ... */
*p++;

Compliant Solution (

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Dereference)

Correcting this example depends on the intent of the programmer. For instance, if dereferencing p was a mistake, then p should not be dereferenced.

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If the intent was to increment the value referred to by p, then parentheses can be used to ensure p is dereferenced and then incremented (see EXP00-A. Use parentheses for precedence of operation).

int *p;
/* ... */
(*p)++

Compliant Solution (

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Memory Mapped Devices)

Another possibility is that p is being using used to reference a memory-mapped device. In this case, the variable p should be declared as volatile.

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\[[Coverity 07|AA. C References#Coverity 07]\] Coverity Prevent User's Manual (3.3.0) (2007).
\[[ISO/IEC PDTR 24772|AA. C References#ISO/IEC PDTR 24772]\] "BRS Leveraging human experience," "BVQ Unspecified Functionality," "KOA Likely incorrect expressions," and "XYQ Dead and Deactivated Code"
\[[MISRA 04|AA. C References#MISRA 04]\] Rule 14.1 and Rule 14.2

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