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use crate::borrow_set::{BorrowData, BorrowSet, TwoPhaseActivation};
use crate::places_conflict;
use crate::AccessDepth;
use crate::BorrowIndex;
use crate::Upvar;
use rustc_data_structures::graph::dominators::Dominators;
use rustc_middle::mir::BorrowKind;
use rustc_middle::mir::{BasicBlock, Body, Field, Location, Place, PlaceRef, ProjectionElem};
use rustc_middle::ty::TyCtxt;
pub(super) fn allow_two_phase_borrow(kind: BorrowKind) -> bool {
kind.allows_two_phase_borrow()
}
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub(super) enum Control {
Continue,
Break,
}
pub(super) fn each_borrow_involving_path<'tcx, F, I, S>(
s: &mut S,
tcx: TyCtxt<'tcx>,
body: &Body<'tcx>,
_location: Location,
access_place: (AccessDepth, Place<'tcx>),
borrow_set: &BorrowSet<'tcx>,
candidates: I,
mut op: F,
) where
F: FnMut(&mut S, BorrowIndex, &BorrowData<'tcx>) -> Control,
I: Iterator<Item = BorrowIndex>,
{
let (access, place) = access_place;
for i in candidates {
let borrowed = &borrow_set[i];
if places_conflict::borrow_conflicts_with_place(
tcx,
body,
borrowed.borrowed_place,
borrowed.kind,
place.as_ref(),
access,
places_conflict::PlaceConflictBias::Overlap,
) {
debug!(
"each_borrow_involving_path: {:?} @ {:?} vs. {:?}/{:?}",
i, borrowed, place, access
);
let ctrl = op(s, i, borrowed);
if ctrl == Control::Break {
return;
}
}
}
}
pub(super) fn is_active<'tcx>(
dominators: &Dominators<BasicBlock>,
borrow_data: &BorrowData<'tcx>,
location: Location,
) -> bool {
debug!("is_active(borrow_data={:?}, location={:?})", borrow_data, location);
let activation_location = match borrow_data.activation_location {
TwoPhaseActivation::NotTwoPhase => return true,
TwoPhaseActivation::NotActivated => return false,
TwoPhaseActivation::ActivatedAt(loc) => loc,
};
if activation_location.dominates(location, dominators) {
return true;
}
let reserve_location = borrow_data.reserve_location.successor_within_block();
if reserve_location.dominates(location, dominators) {
false
} else {
true
}
}
pub(super) fn borrow_of_local_data(place: Place<'_>) -> bool {
!place.is_indirect()
}
pub(crate) fn is_upvar_field_projection<'tcx>(
tcx: TyCtxt<'tcx>,
upvars: &[Upvar<'tcx>],
place_ref: PlaceRef<'tcx>,
body: &Body<'tcx>,
) -> Option<Field> {
let mut place_ref = place_ref;
let mut by_ref = false;
if let Some((place_base, ProjectionElem::Deref)) = place_ref.last_projection() {
place_ref = place_base;
by_ref = true;
}
match place_ref.last_projection() {
Some((place_base, ProjectionElem::Field(field, _ty))) => {
let base_ty = place_base.ty(body, tcx).ty;
if (base_ty.is_closure() || base_ty.is_generator())
&& (!by_ref || upvars[field.index()].by_ref)
{
Some(field)
} else {
None
}
}
_ => None,
}
}