Ineffective comparison of unsigned value in a macro is always true

The CWARN.NOEFFECT.UCMP.GE.MACRO checker flags code in macros, in which there is a comparison of an unsigned value to zero that is always true.

Vulnerability and risk

If 'a' is an unsigned value, the comparisons a >= 0 and 0 <= a are always true. These comparisons have no effect, so it's probable that design intent isn't being accomplished.

Vulnerable code example

  #define POSITIVE_LOOP(x) while (x >= 0) x--;
  int foo(unsigned int a) {
    return 0;

Klocwork flags line 4, in which the macro POSITIVE_LOOP contains a condition that is always true.