bjoernager/rust
bjoernager/rust
1
Fork 0
Code Issues Pull requests Activity

Rollup merge of #138442 - dianne:deref-pat-euv-fix, r=compiler-errors

Browse source 
EUV: fix place of deref pattern's interior's scrutinee

The place previously used here was that of the temporary holding the reference returned by `Deref::deref` or `DerefMut::deref_mut`. However, since the inner pattern of `deref!(inner)` expects the deref-target type itself, this would ICE when that type was inspected (e.g. by the EUV case for slice patterns). This adds a deref projection to fix that.

Since current in-tree consumers of EUV (upvar inference and clippy) don't care about Rvalues, the place could be simplified to `self.cat_rvalue(pat.hir_id, self.pat_ty_adjusted(subpat)?)` to save some cycles. I personally find EUV to be a bit fragile, so I've opted for pedantic correctness. Maybe a `HACK` comment would suffice though?

Fixes #125059

r? `@compiler-errors`
This commit is contained in:
Jacob Pratt 2025-03-14 01:37:35 -04:00 • committed by GitHub
commit f5055722b6
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
3 changed files with 17 additions and 13 deletions
Download patch file Download diff file Expand all files Collapse all files

3
compiler/rustc_hir_typeck/src/expr_use_visitor.rs
View file

@ -1840,7 +1840,8 @@ impl<'tcx, Cx: TypeInformationCtxt<'tcx>, D: Delegate<'tcx>> ExprUseVisitor<'tcx
let ty = self.pat_ty_adjusted(subpat)?;
let ty = Ty::new_ref(self.cx.tcx(), re_erased, ty, mutability);
// A deref pattern generates a temporary.
let place = self.cat_rvalue(pat.hir_id, ty);
let base = self.cat_rvalue(pat.hir_id, ty);
let place = self.cat_deref(pat.hir_id, base)?;
self.cat_pattern(place, subpat, op)?;
}