Reduce span of let else irrefutable_let_patterns warning

compiler/rustc_mir_build/src/thir/pattern/check_match.rs

@@ -79,7 +79,10 @@ impl<'tcx> Visitor<'tcx> for MatchVisitor<'_, '_, 'tcx> {
  intravisit::walk_local(self, loc);
  let els = loc.els;
  if let Some(init) = loc.init && els.is_some() {
- self.check_let(&loc.pat, init, loc.span);
+ // Build a span without the else { ... } as we don't want to underline
+ // the entire else block in the IDE setting.
+ let span = loc.span.with_hi(init.span.hi());
+ self.check_let(&loc.pat, init, span);
  }
 
  let (msg, sp) = match loc.source {
@@ -630,11 +633,6 @@ fn irrefutable_let_patterns(
  count: usize,
  span: Span,
 ) {
- let span = match source {
- LetSource::LetElse(span) => span,
- _ => span,
- };
-
  macro_rules! emit_diag {
  (
  $lint:expr,
@@ -680,7 +678,7 @@ fn irrefutable_let_patterns(
  "removing the guard and adding a `let` inside the match arm"
  );
  }
- LetSource::LetElse(..) => {
+ LetSource::LetElse => {
  emit_diag!(
  lint,
  "`let...else`",
@@ -1127,7 +1125,7 @@ pub enum LetSource {
  GenericLet,
  IfLet,
  IfLetGuard,
- LetElse(Span),
+ LetElse,
  WhileLet,
 }
 
@@ -1156,8 +1154,8 @@ fn let_source_parent(tcx: TyCtxt<'_>, parent: HirId, pat_id: Option<HirId>) -> L
  let parent_parent = hir.get_parent_node(parent);
  let parent_parent_node = hir.get(parent_parent);
  match parent_parent_node {
- hir::Node::Stmt(hir::Stmt { kind: hir::StmtKind::Local(_), span, .. }) => {
- return LetSource::LetElse(*span);
+ hir::Node::Stmt(hir::Stmt { kind: hir::StmtKind::Local(_), .. }) => {
+ return LetSource::LetElse;
  }
  hir::Node::Arm(hir::Arm { guard: Some(hir::Guard::If(_)), .. }) => {
  return LetSource::IfLetGuard;

src/test/ui/let-else/let-else-irrefutable.rs

@@ -1,7 +1,11 @@
 // check-pass
 
-
-
 fn main() {
  let x = 1 else { return }; //~ WARN irrefutable `let...else` pattern
+
+ // Multiline else blocks should not get printed
+ let x = 1 else { //~ WARN irrefutable `let...else` pattern
+ eprintln!("problem case encountered");
+ return
+ };
 }

src/test/ui/let-else/let-else-irrefutable.stderr

@@ -1,12 +1,21 @@
 warning: irrefutable `let...else` pattern
- --> $DIR/let-else-irrefutable.rs:6:5
+ --> $DIR/let-else-irrefutable.rs:4:5
  |
 LL | let x = 1 else { return };
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+ | ^^^^^^^^^
  |
  = note: this pattern will always match, so the `else` clause is useless
  = help: consider removing the `else` clause
  = note: `#[warn(irrefutable_let_patterns)]` on by default
 
-warning: 1 warning emitted
+warning: irrefutable `let...else` pattern
+ --> $DIR/let-else-irrefutable.rs:7:5
+ |
+LL | let x = 1 else {
+ | ^^^^^^^^^
+ |
+ = note: this pattern will always match, so the `else` clause is useless
+ = help: consider removing the `else` clause
+
+warning: 2 warnings emitted