Restrict diagnostic context lifetime of FnCtxt to InferCtxt instead of TyCtxt

compiler/rustc_hir_typeck/src/fn_ctxt/mod.rs

@@ -144,7 +144,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         }
     }
 
-    pub(crate) fn dcx(&self) -> DiagCtxtHandle<'tcx> {
+    pub(crate) fn dcx(&self) -> DiagCtxtHandle<'a> {
         self.infcx.dcx()
     }
 

compiler/rustc_hir_typeck/src/pat.rs

@@ -1881,7 +1881,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         &self,
         pat: &Pat<'_>,
         fields: &'tcx [hir::PatField<'tcx>],
-    ) -> Diag<'tcx> {
+    ) -> Diag<'a> {
         let mut err = self
             .dcx()
             .struct_span_err(pat.span, "pattern requires `..` due to inaccessible fields");
@@ -1973,7 +1973,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         unmentioned_fields: &[(&ty::FieldDef, Ident)],
         have_inaccessible_fields: bool,
         fields: &'tcx [hir::PatField<'tcx>],
-    ) -> Diag<'tcx> {
+    ) -> Diag<'a> {
         let inaccessible = if have_inaccessible_fields { " and inaccessible fields" } else { "" };
         let field_names = if let [(_, field)] = unmentioned_fields {
             format!("field `{field}`{inaccessible}")

compiler/rustc_infer/src/infer/mod.rs

@@ -1607,7 +1607,7 @@ impl<'tcx> InferCtxt<'tcx> {
     }
 }
 
-impl<'tcx> TypeErrCtxt<'_, 'tcx> {
+impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
     // [Note-Type-error-reporting]
     // An invariant is that anytime the expected or actual type is Error (the special
     // error type, meaning that an error occurred when typechecking this expression),
@@ -1623,9 +1623,9 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
         sp: Span,
         mk_diag: M,
         actual_ty: Ty<'tcx>,
-    ) -> Diag<'tcx>
+    ) -> Diag<'a>
     where
-        M: FnOnce(String) -> Diag<'tcx>,
+        M: FnOnce(String) -> Diag<'a>,
     {
         let actual_ty = self.resolve_vars_if_possible(actual_ty);
         debug!("type_error_struct_with_diag({:?}, {:?})", sp, actual_ty);