WIP: funny hack that fixes up spans later

Author: oli-obk

compiler/rustc_errors/src/diagnostic.rs

@@ -1264,6 +1264,14 @@ impl<'a, G: EmissionGuarantee> Diag<'a, G> {
         self
     } }
 
+    with_fn! { with_replace_span,
+    /// Replace all occurrences of the first span with the second one
+    #[rustc_lint_diagnostics]
+    pub fn replace_span(&mut self, before: Span, after: Span) -> &mut Self {
+        self.span.replace(before, after);
+        self
+    } }
+
     #[rustc_lint_diagnostics]
     pub fn is_lint(&mut self, name: String, has_future_breakage: bool) -> &mut Self {
         self.is_lint = Some(IsLint { name, has_future_breakage });

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -1051,27 +1051,21 @@ pub(crate) fn check_type_defn<'tcx>(
                 variant.fields.raw[..variant.fields.len() - unsized_len].iter().enumerate()
             {
                 let last = idx == variant.fields.len() - 1;
-                let field_id = field.did.expect_local();
-                let hir::FieldDef { ty: hir_ty, .. } =
-                    tcx.hir_node_by_def_id(field_id).expect_field();
-                let ty = wfcx.normalize(
-                    hir_ty.span,
-                    None,
-                    tcx.type_of(field.did).instantiate_identity(),
-                );
+                let span = tcx.def_span(field.did);
+                let ty = wfcx.normalize(span, None, tcx.type_of(field.did).instantiate_identity());
                 wfcx.register_bound(
                     traits::ObligationCause::new(
-                        hir_ty.span,
+                        span,
                         wfcx.body_def_id,
                         ObligationCauseCode::FieldSized {
                             adt_kind: adt_def.adt_kind(),
-                            span: hir_ty.span,
+                            field: field.did,
                             last,
                         },
                     ),
                     wfcx.param_env,
                     ty,
-                    tcx.require_lang_item(LangItem::Sized, hir_ty.span),
+                    tcx.require_lang_item(LangItem::Sized, span),
                 );
             }
 

compiler/rustc_hir_typeck/src/expr.rs

@@ -3910,7 +3910,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         expr.span,
                         ObligationCauseCode::FieldSized {
                             adt_kind: AdtKind::Enum,
-                            span: self.tcx.def_span(field.did),
+                            field: field.did,
                             last: false,
                         },
                     );

compiler/rustc_middle/src/traits/mod.rs

@@ -261,7 +261,7 @@ pub enum ObligationCauseCode<'tcx> {
     /// Types of fields (other than the last, except for packed structs) in a struct must be sized.
     FieldSized {
         adt_kind: AdtKind,
-        span: Span,
+        field: DefId,
         last: bool,
     },
 

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

@@ -3121,7 +3121,13 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
             ObligationCauseCode::StructInitializerSized => {
                 err.note("structs must have a statically known size to be initialized");
             }
-            ObligationCauseCode::FieldSized { adt_kind: ref item, last, span } => {
+            ObligationCauseCode::FieldSized { adt_kind: ref item, last, field } => {
+                let def_span = tcx.def_span(field);
+                let span = field
+                    .as_local()
+                    .map(|field| tcx.hir_node_by_def_id(field).expect_field().ty.span)
+                    .unwrap_or(def_span);
+                err.replace_span(def_span, span);
                 match *item {
                     AdtKind::Struct => {
                         if last {