Consolidate obligation cause codes for where clauses

22 files changed, 97 insertions, 134 deletions

diff --git a/compiler/rustc_borrowck/src/region_infer/mod.rs b/compiler/rustc_borrowck/src/region_infer/mod.rs
index e58723c2ec9..167ca7ba045 100644
--- a/compiler/rustc_borrowck/src/region_infer/mod.rs
+++ b/compiler/rustc_borrowck/src/region_infer/mod.rs
@@ -2059,10 +2059,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
                     // We currently do not store the `DefId` in the `ConstraintCategory`
                     // for performances reasons. The error reporting code used by NLL only
                     // uses the span, so this doesn't cause any problems at the moment.
-                    Some(ObligationCauseCode::SpannedWhereClause(
-                        CRATE_DEF_ID.to_def_id(),
-                        predicate_span,
-                    ))
+                    Some(ObligationCauseCode::WhereClause(CRATE_DEF_ID.to_def_id(), predicate_span))
                 } else {
                     None
                 }
diff --git a/compiler/rustc_const_eval/src/transform/check_consts/check.rs b/compiler/rustc_const_eval/src/transform/check_consts/check.rs
index d43dc467c0f..46cc9f69373 100644
--- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs
+++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs
@@ -11,7 +11,7 @@ use rustc_middle::mir::*;
 use rustc_middle::ty::{self, adjustment::PointerCoercion, Ty, TyCtxt};
 use rustc_middle::ty::{Instance, InstanceDef, TypeVisitableExt};
 use rustc_mir_dataflow::Analysis;
-use rustc_span::{sym, Span, Symbol};
+use rustc_span::{sym, Span, Symbol, DUMMY_SP};
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _;
 use rustc_trait_selection::traits::{self, ObligationCauseCode, ObligationCtxt};
 use rustc_type_ir::visit::{TypeSuperVisitable, TypeVisitor};
@@ -738,7 +738,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                 let cause = ObligationCause::new(
                     terminator.source_info.span,
                     self.body.source.def_id().expect_local(),
-                    ObligationCauseCode::WhereClause(callee),
+                    ObligationCauseCode::WhereClause(callee, DUMMY_SP),
                 );
                 let normalized_predicates = ocx.normalize(&cause, param_env, predicates);
                 ocx.register_obligations(traits::predicates_for_generics(
diff --git a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
index b2b82670d8b..db223f9d80f 100644
--- a/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
+++ b/compiler/rustc_hir_analysis/src/check/compare_impl_item.rs
@@ -819,7 +819,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for ImplTraitInTraitCollector<'_, 'tcx> {
                     ObligationCause::new(
                         self.span,
                         self.body_id,
-                        ObligationCauseCode::SpannedWhereClause(proj.def_id, pred_span),
+                        ObligationCauseCode::WhereClause(proj.def_id, pred_span),
                     ),
                     self.param_env,
                     pred,
@@ -2011,11 +2011,7 @@ pub(super) fn check_type_bounds<'tcx>(
         },
     );
     let mk_cause = |span: Span| {
-        let code = if span.is_dummy() {
-            ObligationCauseCode::WhereClause(trait_ty.def_id)
-        } else {
-            ObligationCauseCode::SpannedWhereClause(trait_ty.def_id, span)
-        };
+        let code = ObligationCauseCode::WhereClause(trait_ty.def_id, span);
         ObligationCause::new(impl_ty_span, impl_ty_def_id, code)
     };
 
@@ -2251,8 +2247,7 @@ fn try_report_async_mismatch<'tcx>(
     };
 
     for error in errors {
-        if let ObligationCauseCode::SpannedWhereClause(def_id, _) =
-            *error.root_obligation.cause.code()
+        if let ObligationCauseCode::WhereClause(def_id, _) = *error.root_obligation.cause.code()
             && def_id == async_future_def_id
             && let Some(proj) = error.root_obligation.predicate.to_opt_poly_projection_pred()
             && let Some(proj) = proj.no_bound_vars()
diff --git a/compiler/rustc_hir_analysis/src/check/wfcheck.rs b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
index 0578317f914..e50af9605fd 100644
--- a/compiler/rustc_hir_analysis/src/check/wfcheck.rs
+++ b/compiler/rustc_hir_analysis/src/check/wfcheck.rs
@@ -1550,7 +1550,7 @@ fn check_where_clauses<'tcx>(wfcx: &WfCheckingCtxt<'_, 'tcx>, span: Span, def_id
             let cause = traits::ObligationCause::new(
                 sp,
                 wfcx.body_def_id,
-                ObligationCauseCode::WhereClause(def_id.to_def_id()),
+                ObligationCauseCode::WhereClause(def_id.to_def_id(), DUMMY_SP),
             );
             traits::Obligation::new(tcx, cause, wfcx.param_env, pred)
         });
diff --git a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
index de697b04ebf..6dd59a62a7a 100644
--- a/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
+++ b/compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs
@@ -212,7 +212,7 @@ fn get_impl_args(
             traits::ObligationCause::new(
                 impl1_span,
                 impl1_def_id,
-                traits::ObligationCauseCode::SpannedWhereClause(impl2_node.def_id(), span),
+                traits::ObligationCauseCode::WhereClause(impl2_node.def_id(), span),
             )
         },
     );
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
index 881f726e1da..b32cab6d3f7 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/_impl.rs
@@ -1409,11 +1409,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         hir_id: HirId,
     ) {
         self.add_required_obligations_with_code(span, def_id, args, |idx, span| {
-            if span.is_dummy() {
-                ObligationCauseCode::WhereClauseInExpr(def_id, hir_id, idx)
-            } else {
-                ObligationCauseCode::SpannedWhereClauseInExpr(def_id, span, hir_id, idx)
-            }
+            ObligationCauseCode::WhereClauseInExpr(def_id, span, hir_id, idx)
         })
     }
 
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs
index 26996397659..c3525f175da 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/adjust_fulfillment_errors.rs
@@ -14,8 +14,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         error: &mut traits::FulfillmentError<'tcx>,
     ) -> bool {
-        let (ObligationCauseCode::WhereClauseInExpr(def_id, hir_id, idx)
-        | ObligationCauseCode::SpannedWhereClauseInExpr(def_id, _, hir_id, idx)) =
+        let ObligationCauseCode::WhereClauseInExpr(def_id, _, hir_id, idx) =
             *error.obligation.cause.code().peel_derives()
         else {
             return false;
@@ -512,7 +511,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         expr: &'tcx hir::Expr<'tcx>,
     ) -> Result<&'tcx hir::Expr<'tcx>, &'tcx hir::Expr<'tcx>> {
         match obligation_cause_code {
-            traits::ObligationCauseCode::SpannedWhereClauseInExpr(_, _, _, _) => {
+            traits::ObligationCauseCode::WhereClauseInExpr(_, _, _, _) => {
                 // This is the "root"; we assume that the `expr` is already pointing here.
                 // Therefore, we return `Ok` so that this `expr` can be refined further.
                 Ok(expr)
diff --git a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
index 4bf82355b62..5fa715dc761 100644
--- a/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
+++ b/compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs
@@ -2013,8 +2013,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         for (span, code) in errors_causecode {
             self.dcx().try_steal_modify_and_emit_err(span, StashKey::MaybeForgetReturn, |err| {
                 if let Some(fn_sig) = self.body_fn_sig()
-                    && let ObligationCauseCode::SpannedWhereClauseInExpr(_, _, binding_hir_id, ..) =
-                        code
+                    && let ObligationCauseCode::WhereClauseInExpr(_, _, binding_hir_id, ..) = code
                     && !fn_sig.output().is_unit()
                 {
                     let mut block_num = 0;
@@ -2103,7 +2102,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         //
         // This is because due to normalization, we often register duplicate
         // obligations with misc obligations that are basically impossible to
-        // line back up with a useful SpannedWhereClauseInExpr.
+        // line back up with a useful WhereClauseInExpr.
         for error in not_adjusted {
             for (span, predicate, cause) in &remap_cause {
                 if *predicate == error.obligation.predicate
diff --git a/compiler/rustc_hir_typeck/src/method/confirm.rs b/compiler/rustc_hir_typeck/src/method/confirm.rs
index 56c296fc1c0..007ec7ff378 100644
--- a/compiler/rustc_hir_typeck/src/method/confirm.rs
+++ b/compiler/rustc_hir_typeck/src/method/confirm.rs
@@ -564,16 +564,12 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
         // `self.add_required_obligations(self.span, def_id, &all_args);`
         for obligation in traits::predicates_for_generics(
             |idx, span| {
-                let code = if span.is_dummy() {
-                    ObligationCauseCode::WhereClauseInExpr(def_id, self.call_expr.hir_id, idx)
-                } else {
-                    ObligationCauseCode::SpannedWhereClauseInExpr(
-                        def_id,
-                        span,
-                        self.call_expr.hir_id,
-                        idx,
-                    )
-                };
+                let code = ObligationCauseCode::WhereClauseInExpr(
+                    def_id,
+                    span,
+                    self.call_expr.hir_id,
+                    idx,
+                );
                 traits::ObligationCause::new(self.span, self.body_id, code)
             },
             self.param_env,
diff --git a/compiler/rustc_hir_typeck/src/method/probe.rs b/compiler/rustc_hir_typeck/src/method/probe.rs
index 434bd957498..e9446b862fa 100644
--- a/compiler/rustc_hir_typeck/src/method/probe.rs
+++ b/compiler/rustc_hir_typeck/src/method/probe.rs
@@ -1401,20 +1401,12 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
                     // Convert the bounds into obligations.
                     ocx.register_obligations(traits::predicates_for_generics(
                         |idx, span| {
-                            let code = if span.is_dummy() {
-                                ObligationCauseCode::WhereClauseInExpr(
-                                    impl_def_id,
-                                    self.scope_expr_id,
-                                    idx,
-                                )
-                            } else {
-                                ObligationCauseCode::SpannedWhereClauseInExpr(
-                                    impl_def_id,
-                                    span,
-                                    self.scope_expr_id,
-                                    idx,
-                                )
-                            };
+                            let code = ObligationCauseCode::WhereClauseInExpr(
+                                impl_def_id,
+                                span,
+                                self.scope_expr_id,
+                                idx,
+                            );
                             ObligationCause::new(self.span, self.body_id, code)
                         },
                         self.param_env,
diff --git a/compiler/rustc_hir_typeck/src/method/suggest.rs b/compiler/rustc_hir_typeck/src/method/suggest.rs
index d1891a032e1..0483bd03576 100644
--- a/compiler/rustc_hir_typeck/src/method/suggest.rs
+++ b/compiler/rustc_hir_typeck/src/method/suggest.rs
@@ -832,9 +832,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         (data.impl_or_alias_def_id, data.span)
                     }
                     Some(
-                        ObligationCauseCode::SpannedWhereClauseInExpr(def_id, span, _, _)
-                        | ObligationCauseCode::SpannedWhereClause(def_id, span),
-                    ) => (*def_id, *span),
+                        ObligationCauseCode::WhereClauseInExpr(def_id, span, _, _)
+                        | ObligationCauseCode::WhereClause(def_id, span),
+                    ) if !span.is_dummy() => (*def_id, *span),
                     _ => continue,
                 };
 
diff --git a/compiler/rustc_infer/src/infer/error_reporting/mod.rs b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
index 46310941113..3488517a4ef 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/mod.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/mod.rs
@@ -883,9 +883,10 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                 err.help("...or use `match` instead of `let...else`");
             }
             _ => {
-                if let ObligationCauseCode::SpannedWhereClause(_, span)
-                | ObligationCauseCode::SpannedWhereClauseInExpr(_, span, ..) =
+                if let ObligationCauseCode::WhereClause(_, span)
+                | ObligationCauseCode::WhereClauseInExpr(_, span, ..) =
                     cause.code().peel_derives()
+                    && !span.is_dummy()
                     && let TypeError::RegionsPlaceholderMismatch = terr
                 {
                     err.span_note(*span, "the lifetime requirement is introduced here");
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/mismatched_static_lifetime.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/mismatched_static_lifetime.rs
index b6c38739e9a..fdfce7f8f73 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/mismatched_static_lifetime.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/mismatched_static_lifetime.rs
@@ -38,11 +38,14 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
         let ObligationCauseCode::MatchImpl(parent, impl_def_id) = code else {
             return None;
         };
-        let (ObligationCauseCode::SpannedWhereClause(_, binding_span)
-        | ObligationCauseCode::SpannedWhereClauseInExpr(_, binding_span, ..)) = *parent.code()
+        let (ObligationCauseCode::WhereClause(_, binding_span)
+        | ObligationCauseCode::WhereClauseInExpr(_, binding_span, ..)) = *parent.code()
         else {
             return None;
         };
+        if binding_span.is_dummy() {
+            return None;
+        }
 
         // FIXME: we should point at the lifetime
         let multi_span: MultiSpan = vec![binding_span].into();
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/placeholder_error.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/placeholder_error.rs
index dbd165c093a..31d45133eb0 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/placeholder_error.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/placeholder_error.rs
@@ -10,7 +10,7 @@ use crate::traits::{ObligationCause, ObligationCauseCode};
 use rustc_data_structures::intern::Interned;
 use rustc_errors::{Diag, IntoDiagArg};
 use rustc_hir::def::Namespace;
-use rustc_hir::def_id::DefId;
+use rustc_hir::def_id::{DefId, CRATE_DEF_ID};
 use rustc_middle::ty::error::ExpectedFound;
 use rustc_middle::ty::print::{FmtPrinter, Print, PrintTraitRefExt as _, RegionHighlightMode};
 use rustc_middle::ty::GenericArgsRef;
@@ -240,8 +240,9 @@ impl<'tcx> NiceRegionError<'_, 'tcx> {
         let span = cause.span();
 
         let (leading_ellipsis, satisfy_span, where_span, dup_span, def_id) =
-            if let ObligationCauseCode::WhereClause(def_id)
-            | ObligationCauseCode::WhereClauseInExpr(def_id, ..) = *cause.code()
+            if let ObligationCauseCode::WhereClause(def_id, span)
+            | ObligationCauseCode::WhereClauseInExpr(def_id, span, ..) = *cause.code()
+                && def_id != CRATE_DEF_ID.to_def_id()
             {
                 (
                     true,
diff --git a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
index e5950a7c935..8a1e3a7ac71 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/nice_region_error/static_impl_trait.rs
@@ -214,7 +214,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
                 _ => cause.code(),
             }
             && let (
-                &ObligationCauseCode::WhereClause(item_def_id)
+                &ObligationCauseCode::WhereClause(item_def_id, _)
                 | &ObligationCauseCode::WhereClauseInExpr(item_def_id, ..),
                 None,
             ) = (code, override_error_code)
diff --git a/compiler/rustc_infer/src/infer/error_reporting/note.rs b/compiler/rustc_infer/src/infer/error_reporting/note.rs
index ecbe65fe926..00dd20a2cc2 100644
--- a/compiler/rustc_infer/src/infer/error_reporting/note.rs
+++ b/compiler/rustc_infer/src/infer/error_reporting/note.rs
@@ -357,21 +357,22 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             infer::Subtype(box ref trace)
                 if matches!(
                     &trace.cause.code().peel_derives(),
-                    ObligationCauseCode::SpannedWhereClause(..)
-                        | ObligationCauseCode::SpannedWhereClauseInExpr(..)
+                    ObligationCauseCode::WhereClause(..)
+                        | ObligationCauseCode::WhereClauseInExpr(..)
                 ) =>
             {
                 // Hack to get around the borrow checker because trace.cause has an `Rc`.
-                if let ObligationCauseCode::SpannedWhereClause(_, span)
-                | ObligationCauseCode::SpannedWhereClauseInExpr(_, span, ..) =
+                if let ObligationCauseCode::WhereClause(_, span)
+                | ObligationCauseCode::WhereClauseInExpr(_, span, ..) =
                     &trace.cause.code().peel_derives()
+                    && !span.is_dummy()
                 {
                     let span = *span;
                     self.report_concrete_failure(placeholder_origin, sub, sup)
                         .with_span_note(span, "the lifetime requirement is introduced here")
                 } else {
                     unreachable!(
-                        "control flow ensures we have a `BindingObligation` or `SpannedWhereClauseInExpr` here..."
+                        "control flow ensures we have a `BindingObligation` or `WhereClauseInExpr` here..."
                     )
                 }
             }
diff --git a/compiler/rustc_infer/src/infer/outlives/obligations.rs b/compiler/rustc_infer/src/infer/outlives/obligations.rs
index 94f8a2664f9..e0d23d7629f 100644
--- a/compiler/rustc_infer/src/infer/outlives/obligations.rs
+++ b/compiler/rustc_infer/src/infer/outlives/obligations.rs
@@ -103,8 +103,12 @@ impl<'tcx> InferCtxt<'tcx> {
                 cause.span,
                 sup_type,
                 match cause.code().peel_derives() {
-                    ObligationCauseCode::SpannedWhereClause(_, span)
-                    | ObligationCauseCode::SpannedWhereClauseInExpr(_, span, ..) => Some(*span),
+                    ObligationCauseCode::WhereClause(_, span)
+                    | ObligationCauseCode::WhereClauseInExpr(_, span, ..)
+                        if !span.is_dummy() =>
+                    {
+                        Some(*span)
+                    }
                     _ => None,
                 },
             )
diff --git a/compiler/rustc_middle/src/traits/mod.rs b/compiler/rustc_middle/src/traits/mod.rs
index 6c33a29ea81..fb796bf87a1 100644
--- a/compiler/rustc_middle/src/traits/mod.rs
+++ b/compiler/rustc_middle/src/traits/mod.rs
@@ -247,22 +247,15 @@ pub enum ObligationCauseCode<'tcx> {
     /// A tuple is WF only if its middle elements are `Sized`.
     TupleElem,
 
-    /// Must satisfy all of the where-clause predicates of the
-    /// given item.
-    WhereClause(DefId),
-
-    /// Like `WhereClause`, but carries the span of the
-    /// predicate when it can be identified.
-    SpannedWhereClause(DefId, Span),
-
-    /// Like `WhereClause`, but carries the `HirId` of the
-    /// expression that caused the obligation, and the `usize`
-    /// indicates exactly which predicate it is in the list of
-    /// instantiated predicates.
-    WhereClauseInExpr(DefId, HirId, usize),
-
-    /// Combines `SpannedWhereClause` and `WhereClauseInExpr`.
-    SpannedWhereClauseInExpr(DefId, Span, HirId, usize),
+    /// Represents a clause that comes from a specific item.
+    /// The span corresponds to the clause.
+    WhereClause(DefId, Span),
+
+    /// Like `WhereClause`, but also identifies the expression
+    /// which requires the `where` clause to be proven, and also
+    /// identifies the index of the predicate in the `predicates_of`
+    /// list of the item.
+    WhereClauseInExpr(DefId, Span, HirId, usize),
 
     /// A type like `&'a T` is WF only if `T: 'a`.
     ReferenceOutlivesReferent(Ty<'tcx>),
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index 597effcbbf0..51a4e910d62 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -1205,8 +1205,13 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
 
         let code = match obligation.cause.code() {
             ObligationCauseCode::FunctionArg { parent_code, .. } => parent_code,
-            c @ ObligationCauseCode::WhereClause(_)
-            | c @ ObligationCauseCode::WhereClauseInExpr(..) => c,
+            // FIXME(compiler-errors): This is kind of a mess, but required for obligations
+            // that come from a path expr to affect the *call* expr.
+            c @ ObligationCauseCode::WhereClauseInExpr(_, _, hir_id, _)
+                if self.tcx.hir().span(*hir_id).lo() == span.lo() =>
+            {
+                c
+            }
             c if matches!(
                 span.ctxt().outer_expn_data().kind,
                 ExpnKind::Desugaring(DesugaringKind::ForLoop)
@@ -1262,8 +1267,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             let mut_ref_self_ty_satisfies_pred = mk_result(trait_pred_and_mut_ref);
 
             let (ref_inner_ty_satisfies_pred, ref_inner_ty_mut) =
-                if let ObligationCauseCode::WhereClause(_)
-                | ObligationCauseCode::WhereClauseInExpr(..) = obligation.cause.code()
+                if let ObligationCauseCode::WhereClauseInExpr(..) = obligation.cause.code()
                     && let ty::Ref(_, ty, mutability) = old_pred.self_ty().skip_binder().kind()
                 {
                     (
@@ -1403,10 +1407,8 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
 
         if let ObligationCauseCode::ImplDerived(cause) = &*code {
             try_borrowing(cause.derived.parent_trait_pred, &[])
-        } else if let ObligationCauseCode::SpannedWhereClause(_, _)
-        | ObligationCauseCode::WhereClause(_)
-        | ObligationCauseCode::WhereClauseInExpr(..)
-        | ObligationCauseCode::SpannedWhereClauseInExpr(..) = code
+        } else if let ObligationCauseCode::WhereClause(..)
+        | ObligationCauseCode::WhereClauseInExpr(..) = code
         {
             try_borrowing(poly_trait_pred, &never_suggest_borrow)
         } else {
@@ -2102,10 +2104,10 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
         cause: &ObligationCauseCode<'tcx>,
         err: &mut Diag<'tcx>,
     ) {
-        // First, look for an `SpannedWhereClauseInExpr`, which means we can get
+        // First, look for an `WhereClauseInExpr`, which means we can get
         // the uninstantiated predicate list of the called function. And check
         // that the predicate that we failed to satisfy is a `Fn`-like trait.
-        if let ObligationCauseCode::SpannedWhereClauseInExpr(def_id, _, _, idx) = cause
+        if let ObligationCauseCode::WhereClauseInExpr(def_id, _, _, idx) = cause
             && let predicates = self.tcx.predicates_of(def_id).instantiate_identity(self.tcx)
             && let Some(pred) = predicates.predicates.get(*idx)
             && let ty::ClauseKind::Trait(trait_pred) = pred.kind().skip_binder()
@@ -2746,12 +2748,10 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             ObligationCauseCode::TupleElem => {
                 err.note("only the last element of a tuple may have a dynamically sized type");
             }
-            ObligationCauseCode::WhereClause(_) | ObligationCauseCode::WhereClauseInExpr(..) => {
-                // We hold the `DefId` of the item introducing the obligation, but displaying it
-                // doesn't add user usable information. It always point at an associated item.
-            }
-            ObligationCauseCode::SpannedWhereClause(item_def_id, span)
-            | ObligationCauseCode::SpannedWhereClauseInExpr(item_def_id, span, ..) => {
+            ObligationCauseCode::WhereClause(item_def_id, span)
+            | ObligationCauseCode::WhereClauseInExpr(item_def_id, span, ..)
+                if !span.is_dummy() =>
+            {
                 let item_name = tcx.def_path_str(item_def_id);
                 let short_item_name = with_forced_trimmed_paths!(tcx.def_path_str(item_def_id));
                 let mut multispan = MultiSpan::from(span);
@@ -2882,6 +2882,10 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                     err.help(help);
                 }
             }
+            ObligationCauseCode::WhereClause(..) | ObligationCauseCode::WhereClauseInExpr(..) => {
+                // We hold the `DefId` of the item introducing the obligation, but displaying it
+                // doesn't add user usable information. It always point at an associated item.
+            }
             ObligationCauseCode::Coercion { source, target } => {
                 let source =
                     tcx.short_ty_string(self.resolve_vars_if_possible(source), &mut long_ty_file);
@@ -3802,7 +3806,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             // to an associated type (as seen from `trait_pred`) in the predicate. Like in
             // trait_pred `S: Sum<<Self as Iterator>::Item>` and predicate `i32: Sum<&()>`
             let mut type_diffs = vec![];
-            if let ObligationCauseCode::SpannedWhereClauseInExpr(def_id, _, _, idx) = parent_code
+            if let ObligationCauseCode::WhereClauseInExpr(def_id, _, _, idx) = parent_code
                 && let Some(node_args) = typeck_results.node_args_opt(call_hir_id)
                 && let where_clauses =
                     self.tcx.predicates_of(def_id).instantiate(self.tcx, node_args)
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs
index cdde12af8ea..92fe50883d0 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/type_err_ctxt_ext.rs
@@ -1535,9 +1535,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                     *err,
                 );
                 let code = error.obligation.cause.code().peel_derives().peel_match_impls();
-                if let ObligationCauseCode::SpannedWhereClause(..)
-                | ObligationCauseCode::WhereClause(..)
-                | ObligationCauseCode::SpannedWhereClauseInExpr(..)
+                if let ObligationCauseCode::WhereClause(..)
                 | ObligationCauseCode::WhereClauseInExpr(..) = code
                 {
                     self.note_obligation_cause_code(
@@ -1612,11 +1610,9 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
 
                 let is_normalized_term_expected = !matches!(
                     obligation.cause.code().peel_derives(),
-                    ObligationCauseCode::WhereClause(_)
-                        | ObligationCauseCode::SpannedWhereClause(_, _)
-                        | ObligationCauseCode::WhereClauseInExpr(..)
-                        | ObligationCauseCode::SpannedWhereClauseInExpr(..)
-                        | ObligationCauseCode::Coercion { .. }
+                    |ObligationCauseCode::WhereClause(..)| ObligationCauseCode::WhereClauseInExpr(
+                        ..
+                    ) | ObligationCauseCode::Coercion { .. }
                 );
 
                 let (expected, actual) = if is_normalized_term_expected {
@@ -2447,7 +2443,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
                     }
                 }
 
-                if let ObligationCauseCode::WhereClause(def_id)
+                if let ObligationCauseCode::WhereClause(def_id, _)
                 | ObligationCauseCode::WhereClauseInExpr(def_id, ..) = *obligation.cause.code()
                 {
                     self.suggest_fully_qualified_path(&mut err, def_id, span, trait_ref.def_id());
@@ -2883,12 +2879,15 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
         else {
             return;
         };
-        let (ObligationCauseCode::SpannedWhereClause(item_def_id, span)
-        | ObligationCauseCode::SpannedWhereClauseInExpr(item_def_id, span, ..)) =
+        let (ObligationCauseCode::WhereClause(item_def_id, span)
+        | ObligationCauseCode::WhereClauseInExpr(item_def_id, span, ..)) =
             *obligation.cause.code().peel_derives()
         else {
             return;
         };
+        if span.is_dummy() {
+            return;
+        }
         debug!(?pred, ?item_def_id, ?span);
 
         let (Some(node), true) = (
@@ -3181,10 +3180,7 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             ObligationCauseCode::RustCall => {
                 err.primary_message("functions with the \"rust-call\" ABI must take a single non-self tuple argument");
             }
-            ObligationCauseCode::SpannedWhereClause(def_id, _)
-            | ObligationCauseCode::WhereClause(def_id)
-                if self.tcx.is_fn_trait(*def_id) =>
-            {
+            ObligationCauseCode::WhereClause(def_id, _) if self.tcx.is_fn_trait(*def_id) => {
                 err.code(E0059);
                 err.primary_message(format!(
                     "type parameter to bare `{}` trait must be a tuple",
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index 1e78484f305..f092f42dacf 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -573,11 +573,7 @@ pub fn normalize_inherent_projection<'a, 'b, 'tcx>(
             // cause code, inherent projections will be printed with identity instantiation in
             // diagnostics which is not ideal.
             // Consider creating separate cause codes for this specific situation.
-            if span.is_dummy() {
-                ObligationCauseCode::WhereClause(alias_ty.def_id)
-            } else {
-                ObligationCauseCode::SpannedWhereClause(alias_ty.def_id, span)
-            },
+            ObligationCauseCode::WhereClause(alias_ty.def_id, span),
         );
 
         obligations.push(Obligation::with_depth(
@@ -2130,17 +2126,11 @@ fn assoc_ty_own_obligations<'cx, 'tcx>(
                 | ObligationCauseCode::AscribeUserTypeProvePredicate(..)
         ) {
             obligation.cause.clone()
-        } else if span.is_dummy() {
-            ObligationCause::new(
-                obligation.cause.span,
-                obligation.cause.body_id,
-                ObligationCauseCode::WhereClause(obligation.predicate.def_id),
-            )
         } else {
             ObligationCause::new(
                 obligation.cause.span,
                 obligation.cause.body_id,
-                ObligationCauseCode::SpannedWhereClause(obligation.predicate.def_id, span),
+                ObligationCauseCode::WhereClause(obligation.predicate.def_id, span),
             )
         };
         nested.push(Obligation::with_depth(
diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs
index 2c2b84d4a87..562a82cc73d 100644
--- a/compiler/rustc_trait_selection/src/traits/wf.rs
+++ b/compiler/rustc_trait_selection/src/traits/wf.rs
@@ -568,11 +568,7 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
 
         iter::zip(predicates, origins.into_iter().rev())
             .map(|((pred, span), origin_def_id)| {
-                let code = if span.is_dummy() {
-                    ObligationCauseCode::WhereClause(origin_def_id)
-                } else {
-                    ObligationCauseCode::SpannedWhereClause(origin_def_id, span)
-                };
+                let code = ObligationCauseCode::WhereClause(origin_def_id, span);
                 let cause = self.cause(code);
                 traits::Obligation::with_depth(
                     self.tcx(),