V2022. Implicit type conversion from integer type to enum type.

The diagnostic rule has been added at users' request.

It helps identify implicit type conversions from integer types to enum types. The rule can assist in code refactoring and facilitate bug detection.

The diagnostic rule applies only to the C language.

Below are the examples of constructs for which the analyzer issues warnings.

Example N1:

typedef enum
{
  Horizontal = 0x1,
  Vertical = 0x2
} Orientation;

void foo1()
{
  int pos = 1;
  Orientation orientation = pos;   // V2022
}

In this example, the 'pos' integer value is implicitly converted to a variable of the 'Orientation' type.

Example N2:

Orientation GetOrientation (int pos)
{
  return pos;   // V2022
}

The 'GetOrientation' function returns a value of the 'Orientation' type and implicitly casts the 'pos' value to this type.

Example N3.

Orientation GetOrientation (bool b)
{
  int posOne = 1;
  int posTwo = 2;
  return b ? posOne : posTwo;    // V2022
}

In this example, the function uses the conditional operator (?:) to select between the two integer variables, 'posOne' and 'posTwo', which also results in the implicit type conversion.

Example N4:

void foo2(Orientation o){}

void foo3()
{
  foo2(Horizontal);                 //ok
  foo2(Horizontal | Vertical);      // V2022
}

The 'Horizontal | Vertical' operation results in an integer representing the bitwise result. Passing this value to the 'foo2' function, which takes an argument of the 'Orientation' type, results in the implicit type conversion and may lead to an invalid value being passed.