bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Rudimentary heuristic to insert parentheses when needed for RPIT overcaptures lint

Browse source
This commit is contained in:
Michael Goulet 2024-12-10 20:41:24 +00:00
parent 33c245b9e9
commit e134c74904
4 changed files with 58 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

35
compiler/rustc_trait_selection/src/errors.rs
View file

@ -10,7 +10,7 @@ use rustc_hir as hir;
use rustc_hir::def::DefKind;
use rustc_hir::def_id::{DefId, LocalDefId};
use rustc_hir::intravisit::{Visitor, walk_ty};
use rustc_hir::{FnRetTy, GenericParamKind};
use rustc_hir::{FnRetTy, GenericParamKind, Node};
use rustc_macros::{Diagnostic, Subdiagnostic};
use rustc_middle::ty::print::{PrintTraitRefExt as _, TraitRefPrintOnlyTraitPath};
use rustc_middle::ty::{self, Binder, ClosureKind, FnSig, PolyTraitRef, Region, Ty, TyCtxt};
@ -1888,10 +1888,35 @@ pub fn impl_trait_overcapture_suggestion<'tcx>(
.collect::<Vec<_>>()
.join(", ");
suggs.push((
tcx.def_span(opaque_def_id).shrink_to_hi(),
format!(" + use<{concatenated_bounds}>"),
));
let opaque_hir_id = tcx.local_def_id_to_hir_id(opaque_def_id);
// FIXME: This is a bit too conservative, since it ignores parens already written in AST.
let (lparen, rparen) = match tcx
.hir()
.parent_iter(opaque_hir_id)
.nth(1)
.expect("expected ty to have a parent always")
.1
{
Node::PathSegment(segment)
if segment.args().paren_sugar_output().is_some_and(|ty| ty.hir_id == opaque_hir_id) =>
{
("(", ")")
}
Node::Ty(ty) => match ty.kind {
rustc_hir::TyKind::Ptr(_) | rustc_hir::TyKind::Ref(..) => ("(", ")"),
// FIXME: RPITs are not allowed to be nested in `impl Fn() -> ...`,
// but we eventually could support that, and that would necessitate
// making this more sophisticated.
_ => ("", ""),
},
_ => ("", ""),
};
let rpit_span = tcx.def_span(opaque_def_id);
if !lparen.is_empty() {
suggs.push((rpit_span.shrink_to_lo(), lparen.to_string()));
}
suggs.push((rpit_span.shrink_to_hi(), format!(" + use<{concatenated_bounds}>{rparen}")));
Some(AddPreciseCapturingForOvercapture { suggs, apit_spans })
}