add test for fields of references

[aneksteind]

No description provided.

[kkysen]

remove_outer_deref(*p, self.tcx()) is already computed above on line 238:

                    && place_ty(&remove_outer_deref(*p, self.tcx())).is_region_ptr() =>

Could you de-duplicate this?

[kkysen]

Maybe a try_remove_outer_deref would be useful here:

/// Try to strip the initital [`Deref`](ProjectionElem::Deref)
/// from a [`projection`](PlaceRef::projection) sequence.
pub fn try_remove_outer_deref<'tcx>(p: Place<'tcx>, tcx: TyCtxt<'tcx>) -> Option<Place<'tcx>> {
    // Remove outer deref if present
    match p.as_ref() {
        PlaceRef {
            local,
            projection: &[ref base @ .., ProjectionElem::Deref],
        } => Some(Place {
            local,
            projection: tcx.intern_place_elems(base),
        }),
        _ => None,
    }
}

/// Strip the initital [`Deref`](ProjectionElem::Deref)
/// from a [`projection`](PlaceRef::projection) sequence
/// if there is one.
pub fn remove_outer_deref<'tcx>(p: Place<'tcx>, tcx: TyCtxt<'tcx>) -> Place<'tcx> {
    try_remove_outer_deref(p, tcx).unwrap_or(p)
}

[kkysen]

Could do

            Rvalue::AddressOf(_, p)
                if let Some(source) = try_remove_outer_deref(*p, self.tcx())
                && place_ty(source).is_region_ptr() =>
            {
                // Instrument which local's address is taken
                self.loc(location.successor_within_block(), copy_fn)
                    .arg_var(dest)
                    .source(source)
                    .dest(&dest)
                    .debug_mir(location)
                    .add_to(self);
            }

but that requires #![feature(if_let_guard, let_chains)]. It might be too clunky without those, I think.

[kkysen]

How about the changes in #573?

[kkysen]

I think #573 is probably too big for the scope of this PR, but keep it in my mind for after merging this PR.

[kkysen]

See my improvement PRs.

[fw-immunant]

Approved conditional on fixing the calloc(0, ...) in the test case.