Synopsis

A comparison using ==, <, <=, >, or >= is always false.

Enabled by default

No

Severity/Certainty

Low/Medium

Full description

A comparison using ==, <, <=, >, or >= is always false, based on the values of the arguments of the comparison operator. This often occurs because literal values or macros have been used on one or both sides of the operator. Double-check that the operands and the code logic are correct. This check is identical to MISRAC2004-13.7_b.

Coding standards

Code examples

The following code example fails the check and will give a warning:

int example(void) {
  int x = 10;

  if (x < 10) {  //never true
    return 1;
  }

  return 0;
}

The following code example passes the check and will not give a warning about this issue:

int example(int x) {

  if (x < 10) {  //OK - may be true
    return 1;
  }

  return 0;
}