Synopsis

An unsigned value is compared to see whether it is negative.

Enabled by default

Yes

Severity/Certainty

Low/High

Full description

A comparison is performed on an unsigned value, to see whether it is negative. This comparison always returns false, and is redundant.

Coding standards

Code examples

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

int foo(unsigned int x)
{
  if (x < 0)  //checking an unsigned for negativity
    return 1;
  else
    return 0;
}

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

int foo(unsigned int x)
{
  if (x < 1)  //OK - x might be 0
    return 1;
  else
    return 0;
}