Rollup merge of #106897 - estebank:issue-99430, r=davidtwco

Tweak E0597

CC #99430

4 files changed, 38 insertions, 5 deletions

diff --git a/compiler/rustc_borrowck/src/borrowck_errors.rs b/compiler/rustc_borrowck/src/borrowck_errors.rs
index a4943d11204..2bbb9618dbf 100644
--- a/compiler/rustc_borrowck/src/borrowck_errors.rs
+++ b/compiler/rustc_borrowck/src/borrowck_errors.rs
@@ -37,7 +37,7 @@ impl<'cx, 'tcx> crate::MirBorrowckCtxt<'cx, 'tcx> {
             desc,
         );
 
-        err.span_label(borrow_span, format!("borrow of {} occurs here", borrow_desc));
+        err.span_label(borrow_span, format!("{} is borrowed here", borrow_desc));
         err.span_label(span, format!("use of borrowed {}", borrow_desc));
         err
     }
@@ -250,8 +250,8 @@ impl<'cx, 'tcx> crate::MirBorrowckCtxt<'cx, 'tcx> {
             desc,
         );
 
-        err.span_label(borrow_span, format!("borrow of {} occurs here", desc));
-        err.span_label(span, format!("assignment to borrowed {} occurs here", desc));
+        err.span_label(borrow_span, format!("{} is borrowed here", desc));
+        err.span_label(span, format!("{} is assigned to here but it was already borrowed", desc));
         err
     }
 
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 720bfe2c77a..a1eb2960d7b 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -1736,7 +1736,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 &self.local_names,
                 &mut err,
                 "",
-                None,
+                Some(borrow_span),
                 None,
             );
         }
diff --git a/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs b/compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs
index 2095747097b..19855075ced 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 {
diff --git a/compiler/rustc_borrowck/src/diagnostics/move_errors.rs b/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
index 6db3c858ae7..ea58ad5ae3e 100644
--- a/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/move_errors.rs
@@ -448,7 +448,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
                 };
                 self.note_type_does_not_implement_copy(err, &place_desc, place_ty, Some(span), "");
 
-                use_spans.args_span_label(err, format!("move out of {place_desc} occurs here"));
+                use_spans.args_span_label(err, format!("{place_desc} is moved here"));
             }
         }
     }