No underflow checks in Polyspace Numerical Defects

In following link https://www.mathworks.com/help/bugfinder/numerical-checks.html, different overflow checks are listed, but no underflow checks.

That is why, for example, following will not be detected:

signed char foo = CHAR_MIN;
printf("foo: %d\n", foo);  // foo: -128
foo--;
printf("foo: %d", foo);  // foo: 127

Any idea on why that check is not available?

Answer 1

[Meet]

Hi Ismet,

In C/C++, integer overflow and underflow on 2’s-complement signed types is undefined behavior, hence tools like Bug Finder can detect when a value goes beyond the representable range, limited by compile-time analysis or bounded checks.

Bug Finder does include a checker for CWE‑191 (Integer Underflow / Wraparound), aimed at constant expressions or arithmetic that is statically analyzable.

For more information on this check, refer to the following MathWorks documentation: https://www.mathworks.com/help/bugfinder/ref/cwe191.html

I hope this helps!