Neither `|` nor `|=` is listed as allowed operator.
Does this mean the following code a violation of Rule 4-5-1?
Code:
bool b1 = false;
void f(int x)
{
b1 |= (x == 0);
}
grunwald Wrote:Neither `|` nor `|=` is listed as allowed operator.
Does this mean the following code a violation of Rule 4-5-1?
Code:
bool b1 = false;
void f(int x)
{
b1 |= (x == 0);
}
x |= y is just short for x = x | y and bitwise operators are forbidden by the rationale in this rule.
Code:
FlexeLint for C/C++ (Unix) Vers. 9.00L, Copyright Gimpel Software 1985-2014
--- Module: diy.cpp (C++)
1 //lint -indirect(au-misra-cpp-alt.lnt) -e514 -e1786 -e9141 -e970 -e952
2 bool b1 = false;
3
4 void f(int x)
5 {
_
6 b1 |= (x == 0);
diy.cpp 6 Note 9111: boolean expression used with non-permitted operator ''|'' [MISRA C++ Rule 4-5-1]
diy.cpp 6 Note 9111: boolean expression used with non-permitted operator ''|'' [MISRA C++ Rule 4-5-1]
Remember that any non-zero value will be considered as 'true' within a logical context, which can lead to surprises:
Code:
a = 0x01u; // This is logically 'true'
b = 0x10u; // This is logically 'true'
if ( a & b ) // Result of bit-wise 'and' is 'false'
if ( a && b ) // Result of logical 'and' is true
Rule 4-5-1 helps to enforce a consistent use of boolean types, helping to allowing defects to be detected.
Yes, b1 |= b2 is prohibited
As pointed out by dg1980, |= is a bitwise operator and the rationale of the rule prohibits the use of bitwise operators