diff options
Diffstat (limited to 'compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs')
| -rw-r--r-- | compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs index 209574709..19855075c 100644 --- a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs +++ b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs @@ -1,6 +1,8 @@ //! Print diagnostics to explain why values are borrowed. use rustc_errors::{Applicability, Diagnostic}; +use rustc_hir as hir; +use rustc_hir::intravisit::Visitor; use rustc_index::vec::IndexVec; use rustc_infer::infer::NllRegionVariableOrigin; use rustc_middle::mir::{ @@ -11,6 +13,7 @@ use rustc_middle::ty::adjustment::PointerCast; use rustc_middle::ty::{self, RegionVid, TyCtxt}; use rustc_span::symbol::{kw, Symbol}; use rustc_span::{sym, DesugaringKind, Span}; +use rustc_trait_selection::traits::error_reporting::FindExprBySpan; use crate::region_infer::{BlameConstraint, ExtraConstraintInfo}; use crate::{ @@ -63,6 +66,36 @@ impl<'tcx> BorrowExplanation<'tcx> { borrow_span: Option<Span>, multiple_borrow_span: Option<(Span, Span)>, ) { + if let Some(span) = borrow_span { + let def_id = body.source.def_id(); + if let Some(node) = tcx.hir().get_if_local(def_id) + && let Some(body_id) = node.body_id() + { + let body = tcx.hir().body(body_id); + let mut expr_finder = FindExprBySpan::new(span); + expr_finder.visit_expr(body.value); + if let Some(mut expr) = expr_finder.result { + while let hir::ExprKind::AddrOf(_, _, inner) + | hir::ExprKind::Unary(hir::UnOp::Deref, inner) + | hir::ExprKind::Field(inner, _) + | hir::ExprKind::MethodCall(_, inner, _, _) + | hir::ExprKind::Index(inner, _) = &expr.kind + { + expr = inner; + } + if let hir::ExprKind::Path(hir::QPath::Resolved(None, p)) = expr.kind + && let [hir::PathSegment { ident, args: None, .. }] = p.segments + && let hir::def::Res::Local(hir_id) = p.res + && let Some(hir::Node::Pat(pat)) = tcx.hir().find(hir_id) + { + err.span_label( + pat.span, + &format!("binding `{ident}` declared here"), + ); + } + } + } + } match *self { BorrowExplanation::UsedLater(later_use_kind, var_or_use_span, path_span) => { let message = match later_use_kind { |