[previous] MISRA-C:2004  Rule  12.6:  (Advisory) [next] The operands of logical operators (&&, || and !) should be effectively Boolean. Expressions that are effectively Boolean should not be used as operands to operators other than (&&, ||, !, =, ==, != and ?:).
The logical operators &&, || and ! can be easily confused with the bitwise operators &, | and ~. See 'Boolean expressions' in the glossary.

Example Code: 



/* PRQA S 2982 ++ */

#include "misra.h"
#include "m2cmex.h"

extern S16 test_1206( void )
{
   s16r = ( s16a < s16b ) &  ( s16c > s16d );                /* MISRA Violation */
   s16r = ( s16a < s16b ) |  ( s16c > s16d );                /* MISRA Violation */
   s16r = ( s16c > s16d) * (s16a < s16b);                    /* MISRA Violation */
   s16r = ( s16c > s16d) + s16b;                             /* MISRA Violation */
   s16r = s16r + (s16c > s16d);                              /* MISRA Violation */
   bla  = ( s16a + s16b ) && ( s16c + s16d );                /* MISRA Violation */
   bla  = ( s16a + s16b ) || ( s16c + s16d );                /* MISRA Violation */
   bla  = ( s16a + s16b ) && ( s16c > s16d );                /* MISRA Violation */
   bla  = ( s16a > s16b ) && ( s16c + s16d );                /* MISRA Violation */
   bla  = ! ( s16a + s16b );                                 /* MISRA Violation */
   bla  = (s16a + s16b) > (s16c > s16d);                     /* MISRA Violation */
   bla  = (s16a > s16b) > (s16c + s16d);                     /* MISRA Violation */
   bla  = (s16a > s16b) > (s16c > s16d);                     /* MISRA Violation */
   s16r = ~(s16a > s16b);                                    /* MISRA Violation */
   bla  = s16a && ( s16c < s16d );                           /* MISRA Violation */
   bla  = !s16a;                                             /* MISRA Violation */

   return s16r;
}

QAC messages that encompass this guideline:

3322 Operand of a logical ! operator is a constant expression which is not a 'Boolean' value.
3377 Operand of a logical && or || operator is a constant expression which is not a 'Boolean' value.
4101 Both operands of & operator are 'Boolean' expressions.
4102 Both operands of | operator are 'Boolean' expressions.
4103 Both operands of arithmetic or bitwise operator are 'Boolean' expressions.
4104 Left hand operand of arithmetic or bitwise operator is a 'Boolean' expression.
4105 Right hand operand of arithmetic or bitwise operator is a 'Boolean' expression.
4106 Both operands of && operator are arithmetic or bitwise expressions.
4107 Both operands of || operator are arithmetic or bitwise expressions.
4108 Left hand operand of logical operator is an arithmetic or bitwise expression.
4109 Right hand operand of logical operator is an arithmetic or bitwise expression.
4110 Operand of ! operator is an arithmetic or bitwise expression.
4111 Right hand operand of relational operator is a 'Boolean' expression.
4112 Left hand operand of relational operator is a 'Boolean' expression.
4113 Both operands of relational operator are 'Boolean' expressions.
4114 Operand of ~ operator is a 'Boolean' expression.
4115 Operand of logical && or || operator is not an 'essentially Boolean' expression.
4116 Operand of logical ! operator is not an 'essentially Boolean' expression.


(c) The Motor Industry Research Association, 2004
QA C Source Code Analyser 8.1.2
MISRA-C:2004 Compliance Module 3.2
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