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Only generate OpaqueCast for opaque types

This commit is contained in:
Oli Scherer 2022-07-27 11:58:34 +00:00
parent 40e2de8c41
commit dab1074b91
6 changed files with 47 additions and 23 deletions

View file

@ -293,6 +293,10 @@ impl<'tcx> PlaceBuilder<'tcx> {
self.base
}
pub(crate) fn projection(&self) -> &[PlaceElem<'tcx>] {
&self.projection
}
pub(crate) fn field(self, f: Field, ty: Ty<'tcx>) -> Self {
self.project(PlaceElem::Field(f, ty))
}

View file

@ -244,7 +244,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
.map(|arm| {
let arm = &self.thir[arm];
let arm_has_guard = arm.guard.is_some();
let arm_candidate = Candidate::new(scrutinee.clone(), &arm.pattern, arm_has_guard);
let arm_candidate =
Candidate::new(scrutinee.clone(), &arm.pattern, arm_has_guard, self);
(arm, arm_candidate)
})
.collect()
@ -578,7 +579,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
initializer: PlaceBuilder<'tcx>,
set_match_place: bool,
) -> BlockAnd<()> {
let mut candidate = Candidate::new(initializer.clone(), &irrefutable_pat, false);
let mut candidate = Candidate::new(initializer.clone(), &irrefutable_pat, false, self);
let fake_borrow_temps = self.lower_match_tree(
block,
irrefutable_pat.span,
@ -859,11 +860,16 @@ struct Candidate<'pat, 'tcx> {
}
impl<'tcx, 'pat> Candidate<'pat, 'tcx> {
fn new(place: PlaceBuilder<'tcx>, pattern: &'pat Pat<'tcx>, has_guard: bool) -> Self {
fn new(
place: PlaceBuilder<'tcx>,
pattern: &'pat Pat<'tcx>,
has_guard: bool,
cx: &Builder<'_, 'tcx>,
) -> Self {
Candidate {
span: pattern.span,
has_guard,
match_pairs: smallvec![MatchPair::new(place, pattern)],
match_pairs: smallvec![MatchPair::new(place, pattern, cx)],
bindings: Vec::new(),
ascriptions: Vec::new(),
subcandidates: Vec::new(),
@ -1383,7 +1389,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
debug!("candidate={:#?}\npats={:#?}", candidate, pats);
let mut or_candidates: Vec<_> = pats
.iter()
.map(|pat| Candidate::new(place.clone(), pat, candidate.has_guard))
.map(|pat| Candidate::new(place.clone(), pat, candidate.has_guard, self))
.collect();
let mut or_candidate_refs: Vec<_> = or_candidates.iter_mut().collect();
let otherwise = if candidate.otherwise_block.is_some() {
@ -1779,8 +1785,9 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
let expr_span = expr.span;
let expr_place_builder = unpack!(block = self.lower_scrutinee(block, expr, expr_span));
let wildcard = Pat::wildcard_from_ty(pat.ty);
let mut guard_candidate = Candidate::new(expr_place_builder.clone(), &pat, false);
let mut otherwise_candidate = Candidate::new(expr_place_builder.clone(), &wildcard, false);
let mut guard_candidate = Candidate::new(expr_place_builder.clone(), &pat, false, self);
let mut otherwise_candidate =
Candidate::new(expr_place_builder.clone(), &wildcard, false, self);
let fake_borrow_temps = self.lower_match_tree(
block,
pat.span,
@ -2276,8 +2283,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
let (matching, failure) = self.in_if_then_scope(*let_else_scope, |this| {
let scrutinee = unpack!(block = this.lower_scrutinee(block, init, initializer_span));
let pat = Pat { ty: init.ty, span: else_block_span, kind: PatKind::Wild };
let mut wildcard = Candidate::new(scrutinee.clone(), &pat, false);
let mut candidate = Candidate::new(scrutinee.clone(), pattern, false);
let mut wildcard = Candidate::new(scrutinee.clone(), &pat, false, this);
let mut candidate = Candidate::new(scrutinee.clone(), pattern, false, this);
let fake_borrow_temps = this.lower_match_tree(
block,
initializer_span,

View file

@ -132,7 +132,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
) -> Vec<Candidate<'pat, 'tcx>> {
pats.iter()
.map(|box pat| {
let mut candidate = Candidate::new(place.clone(), pat, candidate.has_guard);
let mut candidate = Candidate::new(place.clone(), pat, candidate.has_guard, self);
self.simplify_candidate(&mut candidate);
candidate
})
@ -164,7 +164,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
});
}
candidate.match_pairs.push(MatchPair::new(match_pair.place, subpattern));
candidate.match_pairs.push(MatchPair::new(match_pair.place, subpattern, self));
Ok(())
}
@ -194,7 +194,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
if let Some(subpattern) = subpattern.as_ref() {
// this is the `x @ P` case; have to keep matching against `P` now
candidate.match_pairs.push(MatchPair::new(match_pair.place, subpattern));
candidate.match_pairs.push(MatchPair::new(match_pair.place, subpattern, self));
}
Ok(())
@ -305,7 +305,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
PatKind::Deref { ref subpattern } => {
let place_builder = match_pair.place.deref();
candidate.match_pairs.push(MatchPair::new(place_builder, subpattern));
candidate.match_pairs.push(MatchPair::new(place_builder, subpattern, self));
Ok(())
}

View file

@ -729,7 +729,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
// e.g., `(x as Variant).0`
let place = downcast_place.clone().field(subpattern.field, subpattern.pattern.ty);
// e.g., `(x as Variant).0 @ P1`
MatchPair::new(place, &subpattern.pattern)
MatchPair::new(place, &subpattern.pattern, self)
});
candidate.match_pairs.extend(consequent_match_pairs);

View file

@ -1,9 +1,11 @@
use crate::build::expr::as_place::PlaceBase;
use crate::build::expr::as_place::PlaceBuilder;
use crate::build::matches::MatchPair;
use crate::build::Builder;
use rustc_middle::mir::*;
use rustc_middle::thir::*;
use rustc_middle::ty;
use rustc_middle::ty::TypeVisitable;
use smallvec::SmallVec;
use std::convert::TryInto;
@ -17,7 +19,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
.iter()
.map(|fieldpat| {
let place = place.clone().field(fieldpat.field, fieldpat.pattern.ty);
MatchPair::new(place, &fieldpat.pattern)
MatchPair::new(place, &fieldpat.pattern, self)
})
.collect()
}
@ -45,7 +47,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
let elem =
ProjectionElem::ConstantIndex { offset: idx as u64, min_length, from_end: false };
let place = place.clone().project(elem);
MatchPair::new(place, subpattern)
MatchPair::new(place, subpattern, self)
}));
if let Some(subslice_pat) = opt_slice {
@ -55,7 +57,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
to: if exact_size { min_length - suffix_len } else { suffix_len },
from_end: !exact_size,
});
match_pairs.push(MatchPair::new(subslice, subslice_pat));
match_pairs.push(MatchPair::new(subslice, subslice_pat, self));
}
match_pairs.extend(suffix.iter().rev().enumerate().map(|(idx, subpattern)| {
@ -66,7 +68,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
from_end: !exact_size,
};
let place = place.clone().project(elem);
MatchPair::new(place, subpattern)
MatchPair::new(place, subpattern, self)
}));
}
@ -95,14 +97,25 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
impl<'pat, 'tcx> MatchPair<'pat, 'tcx> {
pub(in crate::build) fn new(
mut place: PlaceBuilder<'tcx>,
place: PlaceBuilder<'tcx>,
pattern: &'pat Pat<'tcx>,
cx: &Builder<'_, 'tcx>,
) -> MatchPair<'pat, 'tcx> {
// Force the place type to the pattern's type.
// FIXME(oli-obk): can we use this to simplify slice/array pattern hacks?
// FIXME(oli-obk): only add this projection if `place` actually had an opaque
// type before the projection.
place = place.project(ProjectionElem::OpaqueCast(pattern.ty));
let mut place = match place.try_upvars_resolved(cx) {
Ok(val) | Err(val) => val,
};
let may_need_cast = match place.base() {
PlaceBase::Local(local) => {
let ty = Place::ty_from(local, place.projection(), &cx.local_decls, cx.tcx).ty;
ty != pattern.ty && ty.has_opaque_types()
}
_ => true,
};
if may_need_cast {
place = place.project(ProjectionElem::OpaqueCast(pattern.ty));
}
MatchPair { place, pattern }
}
}

View file

@ -893,7 +893,7 @@ where
}
ty::Slice(ety) => self.open_drop_for_array(*ety, None),
_ => bug!("open drop from non-ADT `{:?}`", ty),
_ => span_bug!(self.source_info.span, "open drop from non-ADT `{:?}`", ty),
}
}