Error in generated c++ source code when passing sinks to functions

[0xxon]

# file: foo.spicy

module foo;

function fun(s: sink): bool {
    s.close();
    return True;
}

type Y = unit {
    sink s;
    x: X(self.s);
};


type X = unit (s: sink){
    data: uint8;
    var a: bool;

    on data {
      self.a = fun(s);
    }
};

Causes the following error:

$ spicyc -j ./foo.spicy
/private/var/folders/xg/y2l9jptj6bq6gm7rz1mm2lc80000gn/T/foo_93d27a28ebfe11ba-92d90ada2067c1b3.cc:354:5: error: 'this' argument to member function 'close' has type 'const spicy::rt::Sink', but function is not marked const
    (*s).close();
    ^~~~
/Users/johanna/zeek/install/include/spicy/rt/sink.h:170:10: note: 'close' declared here
    void close() { _close(true); }
         ^
1 error generated.
[error] spicyc: JIT compilation failed

It can be resolved by either calling s.close() in on data, or by changing the function signature to use inout for the sink. However, this still seems like a bug/inconsistency since one does not need inout when passing sinks to other units.

[bbannier]

The issue here is that we generate a C++ function which passes the sink parameter as a const, i.e., a pure in parameter. One way to work around this until a fix is available would be to declare the parameter as inout,

...
function fun(inout s: sink): bool {
...