Find something wrong in this description?  Help us fix it! 
Suede Black Tan On SuedeDark Wine Puppies Slip LeatherChino Chardon Hush SuedeStorm I7vqRW Suede Black Tan On SuedeDark Wine Puppies Slip LeatherChino Chardon Hush SuedeStorm I7vqRW Suede Black Tan On SuedeDark Wine Puppies Slip LeatherChino Chardon Hush SuedeStorm I7vqRW Suede Black Tan On SuedeDark Wine Puppies Slip LeatherChino Chardon Hush SuedeStorm I7vqRW Suede Black Tan On SuedeDark Wine Puppies Slip LeatherChino Chardon Hush SuedeStorm I7vqRW Suede Black Tan On SuedeDark Wine Puppies Slip LeatherChino Chardon Hush SuedeStorm I7vqRW

Why does PolySpace 5.1.1 (R2008a) show a red non-terminating loop (NTL) check in my code?

Suede Black Tan On SuedeDark Wine Puppies Slip LeatherChino Chardon Hush SuedeStorm I7vqRW

Asked by MathWorks Support Team
on 27 Jun 2009

My C code looks as follows. When I run a PolySpace verification, the "for" keyword that is mentioned in the comments is marked red with a message that the loop never terminates. Also, I get another red check for a underflow error. I am using the option "-detect-unsigned-overflows".

int main () {
    int intC;
    unsigned int uintA, uintB, i = 0;
    uintA = 20;
    uintB = 30;
    intC = 10;
    // The following keyword "for" is marked with
    // a red NTL check.
    for(i; i < 10; i++) {
      // Subtraction marked with a red UNFL check
      // for a possible underflow.
      if ((uintA - uintB) < uintC) { // UNFL: 20 - 30
        //...
      }
    }
}

Tags

No tags entered yet.

Wine Hush SuedeStorm Slip Suede Chardon Puppies SuedeDark Black Tan On LeatherChino
Pa'i Black Java OluKai Tan BlackDark Hi'ona TanPaprika q5qwRxE

1 Answer

Answer by MathWorks Support Team Puppies Hush Slip Tan On Suede SuedeDark Wine LeatherChino Chardon SuedeStorm Black on 27 Jun 2009
  Accepted Answer

The red NTL check is caused by the red underflow check (UNFL) within the loop. Correcting the code that causes the UNFL check or removing the option "-detect-unsigned-overflows" will cause the NTL check to disappear.

  0 Comments

Sign in to comment.