Synopsis

(Required) The underlying bit representations of floating-point values shall not be used. To reinterpret bit patterns deliberately, use an explicit cast.

Enabled by default

Yes

Severity/Certainty

Medium/High

Full description

Found a read access to a field of a union following a write access to a different field, which effectively re-interprets the bit pattern with a different type. This check is identical to UNION-type-punning.

Coding standards

Code examples

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

union name {
	int int_field;
	float float_field;
};

void example(void) {
	union name u;
	u.int_field = 10;
	float f = u.float_field;
}

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

union name {
	int int_field;
	float float_field;
};

void example(void) {
	union name u;
	u.int_field = 10;
	float f = u.int_field;
}