ALL EXCEPT constraint not working as intended

[TheActualOtterOne]

Hello,
I found a bug, where using the ALL EXCEPT constraint, is being handled, but inreverse as it should be.
This ASN.1 schema schould work:

Prototype DEFINITIONS AUTOMATIC TAGS ::= BEGIN
    Name ::= VisibleString (ALL EXCEPT ("Cat"))
    firstName Name ::= "Notcat"
END

When I try to comile this, it raises "pycrate_asn1c.err.ASN1ObjErr: Prototype.firstName: internal object 0, value outside of the constraint" this errormessage.
When I change the schema to:

Prototype DEFINITIONS AUTOMATIC TAGS ::= BEGIN
    Name ::= VisibleString (ALL EXCEPT ("Cat"))
    firstName Name ::= "Cat"
END

It compiles and even serilizes the data. Should't the ALL EXCEPT allow everything else but "Cat" in this case?
If you need more information on this, I'll gladly try to help.

[mitshell]

Thanks for reporting. This looks like a bug in the compiler. Such an exclusive constraint is not transposed to the compiled Python module, as this is not a visible constraint (it has no impact on the encoding). I will check where exactly things should be fixed in the compiler, starting here:

pycrate/pycrate_asn1c/asnobj.py

Line 4000 in 8acbc8b

def _parse_const_val(self, const):

, to have at least proper support there.

Having such a constraint available in the compiled Python code and supported in the runtime may need some more work.

[mitshell]

A fix has been introduced in the ASN.1 compiler, to verify values provided in ASN.1 schema: see b71bfee
But the support in the ASN.1 runtime for exclusive values is still missing. A corresponding issue has been opened here: #28