bjoernager/rust
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removed conditional check on bindings_after_at and resulting dead code

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This commit is contained in:
marcusdunn 2021-05-14 18:23:18 -07:00
parent a32d2b43a2
commit 21dee3cbf8
1 changed files with 1 additions and 48 deletions
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49
compiler/rustc_mir_build/src/thir/pattern/check_match.rs
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@ -16,9 +16,8 @@ use rustc_middle::thir::PatKind;
use rustc_middle::ty::{self, Ty, TyCtxt};
use rustc_session::lint::builtin::BINDINGS_WITH_VARIANT_NAME;
use rustc_session::lint::builtin::{IRREFUTABLE_LET_PATTERNS, UNREACHABLE_PATTERNS};
use rustc_session::parse::feature_err;
use rustc_session::Session;
use rustc_span::{sym, Span};
use rustc_span::{Span};
use std::slice;
crate fn check_match(tcx: TyCtxt<'_>, def_id: DefId) {
@ -123,9 +122,6 @@ impl PatCtxt<'_, '_> {
impl<'tcx> MatchVisitor<'_, 'tcx> {
fn check_patterns(&mut self, pat: &Pat<'_>) {
pat.walk_always(|pat| check_borrow_conflicts_in_at_patterns(self, pat));
if !self.tcx.features().bindings_after_at {
check_legality_of_bindings_in_at_patterns(self, pat);
}
check_for_bindings_named_same_as_variants(self, pat);
}
@ -740,46 +736,3 @@ fn check_borrow_conflicts_in_at_patterns(cx: &MatchVisitor<'_, '_>, pat: &Pat<'_
err.emit();
}
}
/// Forbids bindings in `@` patterns. This used to be is necessary for memory safety,
/// because of the way rvalues were handled in the borrow check. (See issue #14587.)
fn check_legality_of_bindings_in_at_patterns(cx: &MatchVisitor<'_, '_>, pat: &Pat<'_>) {
AtBindingPatternVisitor { cx, bindings_allowed: true }.visit_pat(pat);
struct AtBindingPatternVisitor<'a, 'b, 'tcx> {
cx: &'a MatchVisitor<'b, 'tcx>,
bindings_allowed: bool,
}
impl<'v> Visitor<'v> for AtBindingPatternVisitor<'_, '_, '_> {
type Map = intravisit::ErasedMap<'v>;
fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
NestedVisitorMap::None
}
fn visit_pat(&mut self, pat: &Pat<'_>) {
match pat.kind {
hir::PatKind::Binding(.., ref subpat) => {
if !self.bindings_allowed {
feature_err(
&self.cx.tcx.sess.parse_sess,
sym::bindings_after_at,
pat.span,
"pattern bindings after an `@` are unstable",
)
.emit();
}
if subpat.is_some() {
let bindings_were_allowed = self.bindings_allowed;
self.bindings_allowed = false;
intravisit::walk_pat(self, pat);
self.bindings_allowed = bindings_were_allowed;
}
}
_ => intravisit::walk_pat(self, pat),
}
}
}
}