Unexpected cursor kind `CXCursor_VisibilityAttr`

[dschrempf]

While playing around with delayed parse messages, I managed to hit a BUG trace:

[Bug    ] [HsBindgen] [select-parse] 'struct hidden' at "./test.h 1:23"
  Could not select declaration:
    Unexpected cursor kind CXCursor_VisibilityAttr
    Please report this as a bug at https://github.com/well-typed/hs-bindgen/issues/

Relevant C code:

struct __attribute__((visibility("hidden"))) Dependency {
  int x;
};

struct Selected {
  struct Dependency dep;
};

Not sure if this is an issue, or if we should simply close this ticket, but I didn't want to let it slide.

Probably related #876.

[jorisdral]

IIRC we only really handle attributes on function declarations, not anywhere else. Still, attributes are valid on variables, types, and statements as well. It's probably that the parser is not taking into account that attributes might occur there, hence the panic (?). Maybe we should skip over them in such cases? And maybe we should issue messages if we ignore attributes?

[dschrempf]

Exactly, that's also what I thought, but wanted to confirm.

[edsko]

@dschrempf Perhaps this is a good use of the new "bug" level: ignore the attribute, but emit a bug asking people to report it.

For the specific attribute that you list in this ticket, I'm not actually sure if we should do anything with visibility on datatype declarations, seems odd.

[dschrempf]

(I think the visibility argument is applied to the type, but I am by no means an expert here).