1 files changed, 40 insertions, 21 deletions

diff --git a/compiler/rustc_passes/src/layout_test.rs b/compiler/rustc_passes/src/layout_test.rs
index f3c12e0746d..6dacac150d3 100644
--- a/compiler/rustc_passes/src/layout_test.rs
+++ b/compiler/rustc_passes/src/layout_test.rs
@@ -2,11 +2,13 @@ use rustc_ast::Attribute;
 use rustc_hir::def::DefKind;
 use rustc_hir::def_id::LocalDefId;
 use rustc_middle::ty::layout::{HasParamEnv, HasTyCtxt, LayoutError, LayoutOfHelpers, TyAndLayout};
-use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
+use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt};
 use rustc_span::source_map::Spanned;
 use rustc_span::symbol::sym;
 use rustc_span::Span;
 use rustc_target::abi::{HasDataLayout, TargetDataLayout};
+use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt;
+use rustc_trait_selection::{infer::TyCtxtInferExt, traits};
 
 use crate::errors::{
     LayoutAbi, LayoutAlign, LayoutHomogeneousAggregate, LayoutInvalidAttribute, LayoutOf,
@@ -40,9 +42,39 @@ pub fn test_layout(tcx: TyCtxt<'_>) {
     }
 }
 
+pub fn ensure_wf<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    param_env: ParamEnv<'tcx>,
+    ty: Ty<'tcx>,
+    span: Span,
+) -> bool {
+    let pred = ty::ClauseKind::WellFormed(ty.into());
+    let obligation = traits::Obligation::new(
+        tcx,
+        traits::ObligationCause::dummy_with_span(span),
+        param_env,
+        pred,
+    );
+    let infcx = tcx.infer_ctxt().build();
+    let ocx = traits::ObligationCtxt::new(&infcx);
+    ocx.register_obligation(obligation);
+    let errors = ocx.select_all_or_error();
+    if !errors.is_empty() {
+        infcx.err_ctxt().report_fulfillment_errors(&errors);
+        false
+    } else {
+        // looks WF!
+        true
+    }
+}
+
 fn dump_layout_of(tcx: TyCtxt<'_>, item_def_id: LocalDefId, attr: &Attribute) {
     let param_env = tcx.param_env(item_def_id);
     let ty = tcx.type_of(item_def_id).instantiate_identity();
+    let span = tcx.def_span(item_def_id.to_def_id());
+    if !ensure_wf(tcx, param_env, ty, span) {
+        return;
+    }
     match tcx.layout_of(param_env.and(ty)) {
         Ok(ty_layout) => {
             // Check out the `#[rustc_layout(..)]` attribute to tell what to dump.
@@ -51,29 +83,24 @@ fn dump_layout_of(tcx: TyCtxt<'_>, item_def_id: LocalDefId, attr: &Attribute) {
             for meta_item in meta_items {
                 match meta_item.name_or_empty() {
                     sym::abi => {
-                        tcx.sess.emit_err(LayoutAbi {
-                            span: tcx.def_span(item_def_id.to_def_id()),
-                            abi: format!("{:?}", ty_layout.abi),
-                        });
+                        tcx.sess.emit_err(LayoutAbi { span, abi: format!("{:?}", ty_layout.abi) });
                     }
 
                     sym::align => {
                         tcx.sess.emit_err(LayoutAlign {
-                            span: tcx.def_span(item_def_id.to_def_id()),
+                            span,
                             align: format!("{:?}", ty_layout.align),
                         });
                     }
 
                     sym::size => {
-                        tcx.sess.emit_err(LayoutSize {
-                            span: tcx.def_span(item_def_id.to_def_id()),
-                            size: format!("{:?}", ty_layout.size),
-                        });
+                        tcx.sess
+                            .emit_err(LayoutSize { span, size: format!("{:?}", ty_layout.size) });
                     }
 
                     sym::homogeneous_aggregate => {
                         tcx.sess.emit_err(LayoutHomogeneousAggregate {
-                            span: tcx.def_span(item_def_id.to_def_id()),
+                            span,
                             homogeneous_aggregate: format!(
                                 "{:?}",
                                 ty_layout.homogeneous_aggregate(&UnwrapLayoutCx { tcx, param_env })
@@ -90,11 +117,7 @@ fn dump_layout_of(tcx: TyCtxt<'_>, item_def_id: LocalDefId, attr: &Attribute) {
                             )
                         );
                         let ty_layout = format!("{:#?}", *ty_layout);
-                        tcx.sess.emit_err(LayoutOf {
-                            span: tcx.def_span(item_def_id.to_def_id()),
-                            normalized_ty,
-                            ty_layout,
-                        });
+                        tcx.sess.emit_err(LayoutOf { span, normalized_ty, ty_layout });
                     }
 
                     name => {
@@ -105,11 +128,7 @@ fn dump_layout_of(tcx: TyCtxt<'_>, item_def_id: LocalDefId, attr: &Attribute) {
         }
 
         Err(layout_error) => {
-            tcx.sess.emit_fatal(Spanned {
-                node: layout_error.into_diagnostic(),
-
-                span: tcx.def_span(item_def_id.to_def_id()),
-            });
+            tcx.sess.emit_fatal(Spanned { node: layout_error.into_diagnostic(), span });
         }
     }
 }