Synopsis

Prevent or detect domain and range errors in math functions.

Enabled by default

Yes

Severity/Certainty

Medium/Medium

Full description

Range errors usually cannot be prevented because they are dependent on the implementation of floating-point numbers as well as on the function being applied. Instead of preventing range errors, programmers should attempt to detect them and take alternative action if a range error occurs.

Coding standards

Code examples

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

#include <math.h>

void example(double x) {
  double result;
  result = sinh(x);
}

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

#include <math.h>
#include <fenv.h>
#include <errno.h>

void example(double x) {
    double result;
    {
        if (math_errhandling & MATH_ERREXCEPT) {
            feclearexcept(FE_ALL_EXCEPT);
        }
        errno = 0;

        result = sinh(x);

        if ((math_errhandling & MATH_ERRNO) && errno != 0) {
            return;
        } else if ((math_errhandling & MATH_ERREXCEPT) &&
                fetestexcept(FE_INVALID | FE_DIVBYZERO |
                    FE_OVERFLOW | FE_UNDERFLOW) != 0) {
            return;
        }
    }
}