Rollup merge of #108764 - cjgillot:dpm-adapt, r=compiler-errors

Tweaks to -Zdrop-tracking-mir

Split from #107421

3 commits: 1 diagnostic improvement and 2 ICEs.

Author: matthiaskrgr

compiler/rustc_hir_analysis/src/check/check.rs

@@ -1510,6 +1510,14 @@ fn opaque_type_cycle_error(
                     {
                         label_match(interior_ty.ty, interior_ty.span);
                     }
+                    if tcx.sess.opts.unstable_opts.drop_tracking_mir
+                        && let DefKind::Generator = tcx.def_kind(closure_def_id)
+                    {
+                        let generator_layout = tcx.mir_generator_witnesses(closure_def_id);
+                        for interior_ty in &generator_layout.field_tys {
+                            label_match(interior_ty.ty, interior_ty.source_info.span);
+                        }
+                    }
                 }
             }
         }

compiler/rustc_mir_transform/src/generator.rs

@@ -1872,12 +1872,14 @@ fn check_must_not_suspend_def(
     data: SuspendCheckData<'_>,
 ) -> bool {
     if let Some(attr) = tcx.get_attr(def_id, sym::must_not_suspend) {
-        let msg = format!(
-            "{}`{}`{} held across a suspend point, but should not be",
-            data.descr_pre,
-            tcx.def_path_str(def_id),
-            data.descr_post,
-        );
+        let msg = rustc_errors::DelayDm(|| {
+            format!(
+                "{}`{}`{} held across a suspend point, but should not be",
+                data.descr_pre,
+                tcx.def_path_str(def_id),
+                data.descr_post,
+            )
+        });
         tcx.struct_span_lint_hir(
             rustc_session::lint::builtin::MUST_NOT_SUSPEND,
             hir_id,

compiler/rustc_trait_selection/src/solve/fulfill.rs

@@ -149,6 +149,6 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> {
         &mut self,
         _: &InferCtxt<'tcx>,
     ) -> Vec<PredicateObligation<'tcx>> {
-        unimplemented!()
+        std::mem::take(&mut self.obligations)
     }
 }

tests/ui/impl-trait/recursive-impl-trait-type-indirect.drop_tracking_mir.stderr

@@ -114,6 +114,9 @@ error[E0720]: cannot resolve opaque type
    |
 LL | fn generator_hold() -> impl Sized {
    |                        ^^^^^^^^^^ recursive opaque type
+...
+LL |         let x = generator_hold();
+   |             - generator captures itself here
 
 error[E0720]: cannot resolve opaque type
   --> $DIR/recursive-impl-trait-type-indirect.rs:90:26