Move scrutinee `HirId` into `MatchSource::TryDesugar`

15 files changed, 26 insertions, 35 deletions

diff --git a/compiler/rustc_ast_lowering/src/expr.rs b/compiler/rustc_ast_lowering/src/expr.rs
index b23cee14f75..7408b4fb0af 100644
--- a/compiler/rustc_ast_lowering/src/expr.rs
+++ b/compiler/rustc_ast_lowering/src/expr.rs
@@ -1648,7 +1648,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
         hir::ExprKind::Match(
             scrutinee,
             arena_vec![self; break_arm, continue_arm],
-            hir::MatchSource::TryDesugar,
+            hir::MatchSource::TryDesugar(scrutinee.hir_id),
         )
     }
 
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
index 6340f1dcca1..0bfd62d68b2 100644
--- a/compiler/rustc_hir/src/hir.rs
+++ b/compiler/rustc_hir/src/hir.rs
@@ -2148,7 +2148,7 @@ pub enum MatchSource {
     /// A desugared `for _ in _ { .. }` loop.
     ForLoopDesugar,
     /// A desugared `?` operator.
-    TryDesugar,
+    TryDesugar(HirId),
     /// A desugared `<expr>.await`.
     AwaitDesugar,
     /// A desugared `format_args!()`.
@@ -2162,7 +2162,7 @@ impl MatchSource {
         match self {
             Normal => "match",
             ForLoopDesugar => "for",
-            TryDesugar => "?",
+            TryDesugar(_) => "?",
             AwaitDesugar => ".await",
             FormatArgs => "format_args!()",
         }
diff --git a/compiler/rustc_hir_typeck/src/_match.rs b/compiler/rustc_hir_typeck/src/_match.rs
index e565dbfe8d2..5d710239ff3 100644
--- a/compiler/rustc_hir_typeck/src/_match.rs
+++ b/compiler/rustc_hir_typeck/src/_match.rs
@@ -107,14 +107,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
             let (span, code) = match prior_arm {
                 // The reason for the first arm to fail is not that the match arms diverge,
                 // but rather that there's a prior obligation that doesn't hold.
-                None => (
-                    arm_span,
-                    ObligationCauseCode::BlockTailExpression(
-                        arm.body.hir_id,
-                        scrut.hir_id,
-                        match_src,
-                    ),
-                ),
+                None => {
+                    (arm_span, ObligationCauseCode::BlockTailExpression(arm.body.hir_id, match_src))
+                }
                 Some((prior_arm_block_id, prior_arm_ty, prior_arm_span)) => (
                     expr.span,
                     ObligationCauseCode::MatchExpressionArm(Box::new(MatchExpressionArmCause {
@@ -127,7 +122,6 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         scrut_span: scrut.span,
                         source: match_src,
                         prior_arms: other_arms.clone(),
-                        scrut_hir_id: scrut.hir_id,
                         opt_suggest_box_span,
                     })),
                 ),
diff --git a/compiler/rustc_hir_typeck/src/coercion.rs b/compiler/rustc_hir_typeck/src/coercion.rs
index ca616fd1518..f618699fa2b 100644
--- a/compiler/rustc_hir_typeck/src/coercion.rs
+++ b/compiler/rustc_hir_typeck/src/coercion.rs
@@ -1751,7 +1751,7 @@ impl<'tcx, 'exprs, E: AsCoercionSite> CoerceMany<'tcx, 'exprs, E> {
                 ) && !in_external_macro(fcx.tcx.sess, cond_expr.span)
                     && !matches!(
                         cond_expr.kind,
-                        hir::ExprKind::Match(.., hir::MatchSource::TryDesugar)
+                        hir::ExprKind::Match(.., hir::MatchSource::TryDesugar(_))
                     )
             {
                 err.span_label(cond_expr.span, "expected this to be `()`");
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index 5254f0796d8..817115012a4 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -1582,11 +1582,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                 let span = self.get_expr_coercion_span(tail_expr);
                 let cause = self.cause(
                     span,
-                    ObligationCauseCode::BlockTailExpression(
-                        blk.hir_id,
-                        blk.hir_id,
-                        hir::MatchSource::Normal,
-                    ),
+                    ObligationCauseCode::BlockTailExpression(blk.hir_id, hir::MatchSource::Normal),
                 );
                 let ty_for_diagnostic = coerce.merged_ty();
                 // We use coerce_inner here because we want to augment the error
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index 717103ed0b4..0b676850dc7 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -745,8 +745,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             }
             ObligationCauseCode::BlockTailExpression(
                 _,
-                scrut_hir_id,
-                hir::MatchSource::TryDesugar,
+                hir::MatchSource::TryDesugar(scrut_hir_id),
             ) => {
                 if let Some(ty::error::ExpectedFound { expected, .. }) = exp_found {
                     let scrut_expr = self.tcx.hir().expect_expr(scrut_hir_id);
@@ -782,12 +781,11 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                 prior_arm_ty,
                 source,
                 ref prior_arms,
-                scrut_hir_id,
                 opt_suggest_box_span,
                 scrut_span,
                 ..
             }) => match source {
-                hir::MatchSource::TryDesugar => {
+                hir::MatchSource::TryDesugar(scrut_hir_id) => {
                     if let Some(ty::error::ExpectedFound { expected, .. }) = exp_found {
                         let scrut_expr = self.tcx.hir().expect_expr(scrut_hir_id);
                         let scrut_ty = if let hir::ExprKind::Call(_, args) = &scrut_expr.kind {
@@ -2077,7 +2075,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
         if let &(MatchExpressionArm(box MatchExpressionArmCause { source, .. })
             | BlockTailExpression(.., source)
         ) = code
-            && let hir::MatchSource::TryDesugar = source
+            && let hir::MatchSource::TryDesugar(_) = source
             && let Some((expected_ty, found_ty, _, _)) = self.values_str(trace.values)
         {
             suggestions.push(TypeErrorAdditionalDiags::TryCannotConvert {
@@ -2954,11 +2952,11 @@ impl<'tcx> ObligationCauseExt<'tcx> for ObligationCause<'tcx> {
             CompareImplItemObligation { kind: ty::AssocKind::Const, .. } => {
                 ObligationCauseFailureCode::ConstCompat { span, subdiags }
             }
-            BlockTailExpression(.., hir::MatchSource::TryDesugar) => {
+            BlockTailExpression(.., hir::MatchSource::TryDesugar(_)) => {
                 ObligationCauseFailureCode::TryCompat { span, subdiags }
             }
             MatchExpressionArm(box MatchExpressionArmCause { source, .. }) => match source {
-                hir::MatchSource::TryDesugar => {
+                hir::MatchSource::TryDesugar(_) => {
                     ObligationCauseFailureCode::TryCompat { span, subdiags }
                 }
                 _ => ObligationCauseFailureCode::MatchCompat { span, subdiags },
diff --git a/compiler/rustc_middle/src/thir.rs b/compiler/rustc_middle/src/thir.rs
index 8e2e71fd879..ebc1c11902b 100644
--- a/compiler/rustc_middle/src/thir.rs
+++ b/compiler/rustc_middle/src/thir.rs
@@ -346,6 +346,7 @@ pub enum ExprKind<'tcx> {
     /// A `match` expression.
     Match {
         scrutinee: ExprId,
+        scrutinee_hir_id: hir::HirId,
         arms: Box<[ArmId]>,
     },
     /// A block.
diff --git a/compiler/rustc_middle/src/thir/visit.rs b/compiler/rustc_middle/src/thir/visit.rs
index 55ec17423ec..681400dbb94 100644
--- a/compiler/rustc_middle/src/thir/visit.rs
+++ b/compiler/rustc_middle/src/thir/visit.rs
@@ -70,7 +70,7 @@ pub fn walk_expr<'a, 'tcx: 'a, V: Visitor<'a, 'tcx>>(visitor: &mut V, expr: &Exp
             visitor.visit_expr(&visitor.thir()[expr]);
         }
         Loop { body } => visitor.visit_expr(&visitor.thir()[body]),
-        Match { scrutinee, ref arms } => {
+        Match { scrutinee, ref arms, .. } => {
             visitor.visit_expr(&visitor.thir()[scrutinee]);
             for &arm in &**arms {
                 visitor.visit_arm(&visitor.thir()[arm]);
diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs
index 1845d42bf7f..3465759b913 100644
--- a/compiler/rustc_middle/src/traits/mod.rs
+++ b/compiler/rustc_middle/src/traits/mod.rs
@@ -402,7 +402,7 @@ pub enum ObligationCauseCode<'tcx> {
     OpaqueReturnType(Option<(Ty<'tcx>, Span)>),
 
     /// Block implicit return
-    BlockTailExpression(hir::HirId, hir::HirId, hir::MatchSource),
+    BlockTailExpression(hir::HirId, hir::MatchSource),
 
     /// #[feature(trivial_bounds)] is not enabled
     TrivialBound,
@@ -543,7 +543,6 @@ pub struct MatchExpressionArmCause<'tcx> {
     pub scrut_span: Span,
     pub source: hir::MatchSource,
     pub prior_arms: Vec<Span>,
-    pub scrut_hir_id: hir::HirId,
     pub opt_suggest_box_span: Option<Span>,
 }
 
diff --git a/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs b/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs
index 295cddb1e15..fe5190900e9 100644
--- a/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs
+++ b/compiler/rustc_mir_build/src/build/custom/parse/instruction.rs
@@ -65,7 +65,7 @@ impl<'tcx, 'body> ParseCtxt<'tcx, 'body> {
                 let target = self.parse_block(args[1])?;
                 self.parse_call(args[2], destination, target)
             },
-            ExprKind::Match { scrutinee, arms } => {
+            ExprKind::Match { scrutinee, arms, .. } => {
                 let discr = self.parse_operand(*scrutinee)?;
                 self.parse_match(arms, expr.span).map(|t| TerminatorKind::SwitchInt { discr, targets: t })
             },
diff --git a/compiler/rustc_mir_build/src/build/expr/into.rs b/compiler/rustc_mir_build/src/build/expr/into.rs
index c750727903f..a5c86e31a29 100644
--- a/compiler/rustc_mir_build/src/build/expr/into.rs
+++ b/compiler/rustc_mir_build/src/build/expr/into.rs
@@ -47,7 +47,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
             ExprKind::Block { block: ast_block } => {
                 this.ast_block(destination, block, ast_block, source_info)
             }
-            ExprKind::Match { scrutinee, ref arms } => {
+            ExprKind::Match { scrutinee, ref arms, .. } => {
                 this.match_expr(destination, expr_span, block, &this.thir[scrutinee], arms)
             }
             ExprKind::If { cond, then, else_opt, if_then_scope } => {
diff --git a/compiler/rustc_mir_build/src/thir/cx/expr.rs b/compiler/rustc_mir_build/src/thir/cx/expr.rs
index 994ac8a3286..a07ea7f2e1d 100644
--- a/compiler/rustc_mir_build/src/thir/cx/expr.rs
+++ b/compiler/rustc_mir_build/src/thir/cx/expr.rs
@@ -733,6 +733,7 @@ impl<'tcx> Cx<'tcx> {
             },
             hir::ExprKind::Match(ref discr, ref arms, _) => ExprKind::Match {
                 scrutinee: self.mirror_expr(discr),
+                scrutinee_hir_id: discr.hir_id,
                 arms: arms.iter().map(|a| self.convert_arm(a)).collect(),
             },
             hir::ExprKind::Loop(ref body, ..) => {
diff --git a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
index a786e659664..383e80851f0 100644
--- a/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
+++ b/compiler/rustc_mir_build/src/thir/pattern/check_match.rs
@@ -135,10 +135,12 @@ impl<'a, 'tcx> Visitor<'a, 'tcx> for MatchVisitor<'a, '_, 'tcx> {
                 });
                 return;
             }
-            ExprKind::Match { scrutinee, box ref arms } => {
+            ExprKind::Match { scrutinee, scrutinee_hir_id, box ref arms } => {
                 let source = match ex.span.desugaring_kind() {
                     Some(DesugaringKind::ForLoop) => hir::MatchSource::ForLoopDesugar,
-                    Some(DesugaringKind::QuestionMark) => hir::MatchSource::TryDesugar,
+                    Some(DesugaringKind::QuestionMark) => {
+                        hir::MatchSource::TryDesugar(scrutinee_hir_id)
+                    }
                     Some(DesugaringKind::Await) => hir::MatchSource::AwaitDesugar,
                     _ => hir::MatchSource::Normal,
                 };
@@ -277,7 +279,7 @@ impl<'p, 'tcx> MatchVisitor<'_, 'p, 'tcx> {
             | hir::MatchSource::FormatArgs => report_arm_reachability(&cx, &report),
             // Unreachable patterns in try and await expressions occur when one of
             // the arms are an uninhabited type. Which is OK.
-            hir::MatchSource::AwaitDesugar | hir::MatchSource::TryDesugar => {}
+            hir::MatchSource::AwaitDesugar | hir::MatchSource::TryDesugar(_) => {}
         }
 
         // Check if the match is exhaustive.
diff --git a/compiler/rustc_mir_build/src/thir/print.rs b/compiler/rustc_mir_build/src/thir/print.rs
index 903dbeeadfa..3b6276cfeb0 100644
--- a/compiler/rustc_mir_build/src/thir/print.rs
+++ b/compiler/rustc_mir_build/src/thir/print.rs
@@ -321,7 +321,7 @@ impl<'a, 'tcx> ThirPrinter<'a, 'tcx> {
                 print_indented!(self, format!("pat: {:?}", pat), depth_lvl + 1);
                 print_indented!(self, "}", depth_lvl);
             }
-            Match { scrutinee, arms } => {
+            Match { scrutinee, arms, .. } => {
                 print_indented!(self, "Match {", depth_lvl);
                 print_indented!(self, "scrutinee:", depth_lvl + 1);
                 self.print_expr(*scrutinee, depth_lvl + 2);
diff --git a/compiler/rustc_passes/src/check_const.rs b/compiler/rustc_passes/src/check_const.rs
index e70817d7b7c..a39f7e7ffcc 100644
--- a/compiler/rustc_passes/src/check_const.rs
+++ b/compiler/rustc_passes/src/check_const.rs
@@ -45,7 +45,7 @@ impl NonConstExpr {
 
             Self::Loop(ForLoop) | Self::Match(ForLoopDesugar) => &[sym::const_for],
 
-            Self::Match(TryDesugar) => &[sym::const_try],
+            Self::Match(TryDesugar(_)) => &[sym::const_try],
 
             // All other expressions are allowed.
             Self::Loop(Loop | While) | Self::Match(Normal | FormatArgs) => &[],