use var_debug_info for arg_name

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -16,6 +16,7 @@ use rustc_hir::{CoroutineKind, CoroutineSource, LangItem};
 use rustc_middle::bug;
 use rustc_middle::hir::nested_filter::OnlyBodies;
 use rustc_middle::mir::tcx::PlaceTy;
+use rustc_middle::mir::VarDebugInfoContents;
 use rustc_middle::mir::{
  self, AggregateKind, BindingForm, BorrowKind, CallSource, ClearCrossCrate, ConstraintCategory,
  FakeBorrowKind, FakeReadCause, LocalDecl, LocalInfo, LocalKind, Location, MutBorrowKind,
@@ -495,7 +496,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
  }
  }
 
- self.suggest_ref_for_dbg_args(expr, span, move_span, err);
+ self.suggest_ref_for_dbg_args(expr, place, move_span, err);
 
  // it's useless to suggest inserting `ref` when the span don't comes from local code
  if let Some(pat) = finder.pat
@@ -522,22 +523,23 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
  fn suggest_ref_for_dbg_args(
  &self,
  body: &hir::Expr<'_>,
- span: Option<Span>,
+ place: &Place<'tcx>,
  move_span: Span,
- err: &mut Diag<'tcx>,
+ err: &mut Diag<'infcx>,
  ) {
- let sm = self.infcx.tcx.sess.source_map();
- let arg_code = if let Some(span) = span
- && let Ok(code) = sm.span_to_snippet(span)
- {
- code
+ let var_info = self.body.var_debug_info.iter().find(|info| match info.value {
+ VarDebugInfoContents::Place(ref p) => p == place,
+ _ => false,
+ });
+ let arg_name = if let Some(var_info) = var_info {
+ var_info.name.to_string()
  } else {
  return;
  };
  struct MatchArgFinder {
  expr_span: Span,
  match_arg_span: Option<Span>,
- arg_code: String,
+ arg_name: String,
  }
  impl Visitor<'_> for MatchArgFinder {
  fn visit_expr(&mut self, e: &hir::Expr<'_>) {
@@ -547,7 +549,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
  _,
  path @ Path { segments: [seg], .. },
  )) = &expr.kind
- && seg.ident.name.as_str() == &self.arg_code
+ && seg.ident.name.as_str() == &self.arg_name
  && self.expr_span.source_callsite().contains(expr.span)
  {
  self.match_arg_span = Some(path.span);
@@ -556,7 +558,7 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, '_, 'infcx, 'tcx> {
  }
  }
 
- let mut finder = MatchArgFinder { expr_span: move_span, match_arg_span: None, arg_code };
+ let mut finder = MatchArgFinder { expr_span: move_span, match_arg_span: None, arg_name };
  finder.visit_expr(body);
  if let Some(macro_arg_span) = finder.match_arg_span {
  err.span_suggestion_verbose(