Skip chained OpaqueCast when building captures.

This commit is contained in:
Camille GILLOT 2022-10-09 16:15:16 +00:00
parent 8796e7a9cf
commit e828ce53b9
3 changed files with 25 additions and 8 deletions

View File

@ -17,6 +17,7 @@ use rustc_target::abi::VariantIdx;
use rustc_index::vec::Idx;
use std::assert_matches::assert_matches;
use std::iter;
/// The "outermost" place that holds this value.
@ -232,22 +233,20 @@ fn strip_prefix<'tcx>(
projections: Vec<PlaceElem<'tcx>>,
prefix_projections: &[HirProjection<'tcx>],
) -> impl Iterator<Item = PlaceElem<'tcx>> {
let mut iter = projections.into_iter();
let mut next = || match iter.next()? {
let mut iter = projections
.into_iter()
// Filter out opaque casts, they are unnecessary in the prefix.
ProjectionElem::OpaqueCast(..) => iter.next(),
other => Some(other),
};
.filter(|elem| !matches!(elem, ProjectionElem::OpaqueCast(..)));
for projection in prefix_projections {
match projection.kind {
HirProjectionKind::Deref => {
assert!(matches!(next(), Some(ProjectionElem::Deref)));
assert_matches!(iter.next(), Some(ProjectionElem::Deref));
}
HirProjectionKind::Field(..) => {
if base_ty.is_enum() {
assert!(matches!(next(), Some(ProjectionElem::Downcast(..))));
assert_matches!(iter.next(), Some(ProjectionElem::Downcast(..)));
}
assert!(matches!(next(), Some(ProjectionElem::Field(..))));
assert_matches!(iter.next(), Some(ProjectionElem::Field(..)));
}
HirProjectionKind::Index | HirProjectionKind::Subslice => {
bug!("unexpected projection kind: {:?}", projection);

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@ -2,6 +2,7 @@
//!
//! This crate also contains the match exhaustiveness and usefulness checking.
#![allow(rustc::potential_query_instability)]
#![feature(assert_matches)]
#![feature(box_patterns)]
#![feature(control_flow_enum)]
#![feature(if_let_guard)]

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@ -0,0 +1,17 @@
// edition:2021
// check-pass
pub struct Example<'a, T> {
a: T,
b: &'a T,
}
impl<'a, T> Example<'a, T> {
pub fn error_trying_to_destructure_self_in_closure(self) {
let closure = || {
let Self { a, b } = self;
};
}
}
fn main() {}