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Fixed incorrect reporting of errors when checking borrows in drops.

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David Wood 2018-01-31 23:46:05 +00:00
parent 673d97e3ca
commit 6493ab6f2a
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GPG key ID: 01760B4F9F53F154
1 changed files with 40 additions and 10 deletions
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50
src/librustc_mir/borrow_check/mod.rs
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@ -2073,7 +2073,7 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
/// currently in, when such distinction matters.
fn each_borrow_involving_path<F>(
&mut self,
_context: Context,
context: Context,
access_place: (ShallowOrDeep, &Place<'tcx>),
flow_state: &Flows<'cx, 'gcx, 'tcx>,
mut op: F,
@ -2085,20 +2085,50 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
// FIXME: analogous code in check_loans first maps `place` to
// its base_path.
// When this function is called as a result of an `access_terminator` call attempting
// to drop a struct, if that struct does not have a destructor, then we need to check
// each of the fields in the struct. See #47703.
let (access, places) = if let ContextKind::Drop = context.kind {
let ty = place.ty(self.mir, self.tcx).to_ty(self.tcx);
match ty.sty {
ty::TyAdt(def, substs) if def.is_struct() && !def.has_dtor(self.tcx) => {
let mut places = Vec::new();
for (index, field) in def.all_fields().enumerate() {
let proj = Projection {
base: place.clone(),
elem: ProjectionElem::Field(Field::new(index),
field.ty(self.tcx, substs)),
};
places.push(Place::Projection(Box::new(proj)));
}
(ShallowOrDeep::Shallow(None), places)
},
_ => (access, vec![ place.clone() ]),
}
} else {
(access, vec![ place.clone() ])
};
let data = flow_state.borrows.operator().borrows();
// check for loan restricting path P being used. Accounts for
// borrows of P, P.a.b, etc.
let mut elems_incoming = flow_state.borrows.elems_incoming();
while let Some(i) = elems_incoming.next() {
let borrowed = &data[i.borrow_index()];
for place in places {
let mut elems_incoming = flow_state.borrows.elems_incoming();
while let Some(i) = elems_incoming.next() {
let borrowed = &data[i.borrow_index()];
if self.places_conflict(&borrowed.borrowed_place, place, access) {
debug!("each_borrow_involving_path: {:?} @ {:?} vs. {:?}/{:?}",
i, borrowed, place, access);
let ctrl = op(self, i, borrowed);
if ctrl == Control::Break {
return;
if self.places_conflict(&borrowed.borrowed_place, &place, access) {
debug!("each_borrow_involving_path: {:?} @ {:?} vs. {:?}/{:?}",
i, borrowed, place, access);
let ctrl = op(self, i, borrowed);
if ctrl == Control::Break {
return;
}
}
}
}