Use more detailed spans in dyn compat errors within bodies

3 files changed, 13 insertions, 6 deletions

diff --git a/compiler/rustc_hir_analysis/src/collect.rs b/compiler/rustc_hir_analysis/src/collect.rs
index f5206d9a015..8a2edd843f2 100644
--- a/compiler/rustc_hir_analysis/src/collect.rs
+++ b/compiler/rustc_hir_analysis/src/collect.rs
@@ -31,7 +31,7 @@ use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::intravisit::{self, InferKind, Visitor, VisitorExt, walk_generics};
 use rustc_hir::{self as hir, GenericParamKind, HirId, Node, PreciseCapturingArgKind};
 use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
-use rustc_infer::traits::ObligationCause;
+use rustc_infer::traits::{DynCompatibilityViolation, ObligationCause};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::util::{Discr, IntTypeExt};
@@ -40,7 +40,7 @@ use rustc_middle::{bug, span_bug};
 use rustc_span::{DUMMY_SP, Ident, Span, Symbol, kw, sym};
 use rustc_trait_selection::error_reporting::traits::suggestions::NextTypeParamName;
 use rustc_trait_selection::infer::InferCtxtExt;
-use rustc_trait_selection::traits::ObligationCtxt;
+use rustc_trait_selection::traits::{ObligationCtxt, hir_ty_lowering_dyn_compatibility_violations};
 use tracing::{debug, instrument};
 
 use crate::errors;
@@ -625,6 +625,10 @@ impl<'tcx> HirTyLowerer<'tcx> for ItemCtxt<'tcx> {
 
         (input_tys, output_ty)
     }
+
+    fn dyn_compatibility_violations(&self, trait_def_id: DefId) -> Vec<DynCompatibilityViolation> {
+        hir_ty_lowering_dyn_compatibility_violations(self.tcx, trait_def_id)
+    }
 }
 
 /// Synthesize a new lifetime name that doesn't clash with any of the lifetimes already present.
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/dyn_compatibility.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/dyn_compatibility.rs
index 9e44b645aca..fb65c9a8929 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/dyn_compatibility.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/dyn_compatibility.rs
@@ -11,7 +11,7 @@ use rustc_middle::ty::{
 };
 use rustc_span::{ErrorGuaranteed, Span};
 use rustc_trait_selection::error_reporting::traits::report_dyn_incompatibility;
-use rustc_trait_selection::traits::{self, hir_ty_lowering_dyn_compatibility_violations};
+use rustc_trait_selection::traits;
 use smallvec::{SmallVec, smallvec};
 use tracing::{debug, instrument};
 
@@ -97,8 +97,7 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
         // to avoid ICEs.
         for (clause, span) in user_written_bounds {
             if let Some(trait_pred) = clause.as_trait_clause() {
-                let violations =
-                    hir_ty_lowering_dyn_compatibility_violations(tcx, trait_pred.def_id());
+                let violations = self.dyn_compatibility_violations(trait_pred.def_id());
                 if !violations.is_empty() {
                     let reported = report_dyn_incompatibility(
                         tcx,
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
index 6b21bbbfcd8..a5dd17b4d63 100644
--- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
+++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
@@ -33,7 +33,7 @@ use rustc_hir::def::{CtorKind, CtorOf, DefKind, Res};
 use rustc_hir::def_id::{DefId, LocalDefId};
 use rustc_hir::{self as hir, AnonConst, GenericArg, GenericArgs, HirId};
 use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
-use rustc_infer::traits::ObligationCause;
+use rustc_infer::traits::{DynCompatibilityViolation, ObligationCause};
 use rustc_middle::middle::stability::AllowUnstable;
 use rustc_middle::mir::interpret::LitToConstInput;
 use rustc_middle::ty::print::PrintPolyTraitRefExt as _;
@@ -200,6 +200,10 @@ pub trait HirTyLowerer<'tcx> {
     {
         self
     }
+
+    /// Performs minimalistic dyn compat checks outside of bodies, but full within bodies.
+    /// Outside of bodies we could end up in cycles, so we delay most checks to later phases.
+    fn dyn_compatibility_violations(&self, trait_def_id: DefId) -> Vec<DynCompatibilityViolation>;
 }
 
 /// The "qualified self" of an associated item path.