Split ObligationCauseCode::BinOp for unops to UnOp

Author: estebank

compiler/rustc_hir_typeck/src/op.rs

@@ -962,13 +962,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         let (opt_rhs_expr, opt_rhs_ty) = opt_rhs.unzip();
         let cause = self.cause(
             span,
-            ObligationCauseCode::BinOp {
-                lhs_hir_id: lhs_expr.hir_id,
-                rhs_hir_id: opt_rhs_expr.map(|expr| expr.hir_id),
-                rhs_span: opt_rhs_expr.map(|expr| expr.span),
-                rhs_is_lit: opt_rhs_expr
-                    .is_some_and(|expr| matches!(expr.kind, hir::ExprKind::Lit(_))),
-                output_ty: expected.only_has_type(self),
+            match opt_rhs_expr {
+                Some(rhs) => ObligationCauseCode::BinOp {
+                    lhs_hir_id: lhs_expr.hir_id,
+                    rhs_hir_id: rhs.hir_id,
+                    rhs_span: rhs.span,
+                    rhs_is_lit: matches!(rhs.kind, hir::ExprKind::Lit(_)),
+                    output_ty: expected.only_has_type(self),
+                },
+                None => ObligationCauseCode::UnOp { hir_id: lhs_expr.hir_id },
             },
         );
 

compiler/rustc_middle/src/traits/mod.rs

@@ -389,10 +389,14 @@ pub enum ObligationCauseCode<'tcx> {
     /// against.
     MatchImpl(ObligationCause<'tcx>, DefId),
 
+    UnOp {
+        hir_id: HirId,
+    },
+
     BinOp {
         lhs_hir_id: HirId,
-        rhs_hir_id: Option<HirId>,
-        rhs_span: Option<Span>,
+        rhs_hir_id: HirId,
+        rhs_span: Span,
         rhs_is_lit: bool,
         output_ty: Option<Ty<'tcx>>,
     },

compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs

@@ -963,8 +963,8 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         trait_pred: ty::PolyTraitPredicate<'tcx>,
         err: &mut Diag<'_>,
     ) -> bool {
-        if let ObligationCauseCode::BinOp { lhs_hir_id, .. } = obligation.cause.code()
-            && let hir::Node::Expr(expr) = self.tcx.hir_node(*lhs_hir_id)
+        if let ObligationCauseCode::UnOp { hir_id, .. } = obligation.cause.code()
+            && let hir::Node::Expr(expr) = self.tcx.hir_node(*hir_id)
             && let hir::ExprKind::Unary(hir::UnOp::Neg, inner) = expr.kind
             && let hir::ExprKind::Lit(lit) = inner.kind
             && let LitKind::Int(_, LitIntType::Unsuffixed) = lit.node
@@ -2769,9 +2769,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         suggested: bool,
     ) {
         let body_def_id = obligation.cause.body_id;
-        let span = if let ObligationCauseCode::BinOp { rhs_span: Some(rhs_span), .. } =
-            obligation.cause.code()
-        {
+        let span = if let ObligationCauseCode::BinOp { rhs_span, .. } = obligation.cause.code() {
             *rhs_span
         } else {
             span

compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs

@@ -554,7 +554,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                 return true;
             }
         } else if let (
-            ObligationCauseCode::BinOp { lhs_hir_id, rhs_hir_id: Some(rhs_hir_id), .. },
+            ObligationCauseCode::BinOp { lhs_hir_id, rhs_hir_id, .. },
             predicate,
         ) = code.peel_derives_with_predicate()
             && let Some(typeck_results) = &self.typeck_results
@@ -2801,6 +2801,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
             | ObligationCauseCode::QuestionMark
             | ObligationCauseCode::CheckAssociatedTypeBounds { .. }
             | ObligationCauseCode::LetElse
+            | ObligationCauseCode::UnOp { .. }
             | ObligationCauseCode::BinOp { .. }
             | ObligationCauseCode::AscribeUserTypeProvePredicate(..)
             | ObligationCauseCode::AlwaysApplicableImpl
@@ -3839,9 +3840,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         trait_pred: ty::PolyTraitPredicate<'tcx>,
     ) {
         let rhs_span = match obligation.cause.code() {
-            ObligationCauseCode::BinOp { rhs_span: Some(span), rhs_is_lit, .. } if *rhs_is_lit => {
-                span
-            }
+            ObligationCauseCode::BinOp { rhs_span, rhs_is_lit, .. } if *rhs_is_lit => rhs_span,
             _ => return,
         };
         if let ty::Float(_) = trait_pred.skip_binder().self_ty().kind()
@@ -5108,16 +5107,12 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         let tcx = self.tcx;
         let predicate = predicate.upcast(tcx);
         match *cause_code {
-            ObligationCauseCode::BinOp {
-                lhs_hir_id,
-                rhs_hir_id: Some(rhs_hir_id),
-                rhs_span: Some(rhs_span),
-                ..
-            } if let Some(typeck_results) = &self.typeck_results
-                && let hir::Node::Expr(lhs) = tcx.hir_node(lhs_hir_id)
-                && let hir::Node::Expr(rhs) = tcx.hir_node(rhs_hir_id)
-                && let Some(lhs_ty) = typeck_results.expr_ty_opt(lhs)
-                && let Some(rhs_ty) = typeck_results.expr_ty_opt(rhs) =>
+            ObligationCauseCode::BinOp { lhs_hir_id, rhs_hir_id, rhs_span, .. }
+                if let Some(typeck_results) = &self.typeck_results
+                    && let hir::Node::Expr(lhs) = tcx.hir_node(lhs_hir_id)
+                    && let hir::Node::Expr(rhs) = tcx.hir_node(rhs_hir_id)
+                    && let Some(lhs_ty) = typeck_results.expr_ty_opt(lhs)
+                    && let Some(rhs_ty) = typeck_results.expr_ty_opt(rhs) =>
             {
                 if let Some(pred) = predicate.as_trait_clause()
                     && tcx.is_lang_item(pred.def_id(), LangItem::PartialEq)