MISRA.STMT.COND.NOT_BOOLEAN.2012

The controlling expression of an if statement and the controlling expression of an iteration-statement shall have essentially Boolean type.

MISRA C 2012 Rule 14.4: The controlling expression of an if statement and the controlling expression of an iteration-statement shall have essentially Boolean type

Category: Required

Analysis: Decidable, Single Translation Unit

Applies to: C90, C99

Amplification

The controlling expression of a for statement is optional. The rule does not require the expression to be present but does require it to have essentially Boolean type if it is present.

Rationale

Strong typing requires the controlling expression of an if statement or iteration-statement to have essentially Boolean type.

Example

int32_t *p, *q;

while ( p )                /* Non-compliant - p is a pointer */ 
{ 
}  

while ( q != NULL )       /* Compliant                        */
{
}

while ( true )            /* Compliant                        */ 
{
}

extern bool_t flag;

while ( flag )             /* Compliant                       */ 
{
}

int32_t i;

if ( i )                   /* Non-compliant                   */ 
{
}

if ( i != 0 )              /* Compliant                       */ 
{ 
}

See also

Rule 14.2, Rule 20.8