Rollup merge of rust-lang#117858 - compiler-errors:span, r=lcnr

Compute layout with spans for better cycle errors in coroutines Split out from rust-lang#117703, this PR at least gives us a nicer span to point at when we hit a cycle error in coroutine layout cycles.

Author: TaKO8Ki

compiler/rustc_ast_lowering/src/expr.rs

@@ -792,8 +792,11 @@ impl<'hir> LoweringContext<'_, 'hir> {
  // debuggers and debugger extensions expect it to be called `__awaitee`. They use
  // this name to identify what is being awaited by a suspended async functions.
  let awaitee_ident = Ident::with_dummy_span(sym::__awaitee);
- let (awaitee_pat, awaitee_pat_hid) =
- self.pat_ident_binding_mode(span, awaitee_ident, hir::BindingAnnotation::MUT);
+ let (awaitee_pat, awaitee_pat_hid) = self.pat_ident_binding_mode(
+ gen_future_span,
+ awaitee_ident,
+ hir::BindingAnnotation::MUT,
+ );
 
  let task_context_ident = Ident::with_dummy_span(sym::_task_context);
 

compiler/rustc_ty_utils/src/layout.rs

@@ -740,11 +740,11 @@ fn coroutine_layout<'tcx>(
  };
  let tag_layout = cx.tcx.mk_layout(LayoutS::scalar(cx, tag));
 
- let promoted_layouts = ineligible_locals
- .iter()
- .map(|local| subst_field(info.field_tys[local].ty))
- .map(|ty| Ty::new_maybe_uninit(tcx, ty))
-  .map(|ty| Ok(cx.layout_of(ty)?.layout));
+ let promoted_layouts = ineligible_locals.iter().map(|local| {
+ let field_ty = subst_field(info.field_tys[local].ty);
+ let uninit_ty = Ty::new_maybe_uninit(tcx, field_ty);
+ Ok(cx.spanned_layout_of(uninit_ty, info.field_tys[local].source_info.span)?.layout)
+ });
  let prefix_layouts = args
  .as_coroutine()
  .prefix_tys()

tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir

@@ -14,7 +14,7 @@
  Static,
  ),
  source_info: SourceInfo {
- span: $DIR/async_await.rs:16:9: 16:14 (#8),
+ span: $DIR/async_await.rs:16:5: 16:14 (#9),
  scope: scope[0],
  },
  ignore_for_traits: false,
@@ -32,7 +32,7 @@
  Static,
  ),
  source_info: SourceInfo {
- span: $DIR/async_await.rs:17:9: 17:14 (#10),
+ span: $DIR/async_await.rs:17:5: 17:14 (#11),
  scope: scope[0],
  },
  ignore_for_traits: false,

tests/ui/type-alias-impl-trait/indirect-recursion-issue-112047.rs

@@ -1,6 +1,5 @@
 // edition: 2021
 // build-fail
-//~^^ ERROR cycle detected when computing layout of
 
 #![feature(impl_trait_in_assoc_type)]
 
@@ -21,6 +20,7 @@ impl Recur for () {
 
  fn recur(self) -> Self::Recur {
  async move { recur(self).await; }
+ //~^ ERROR cycle detected when computing layout of
  }
 }
 

tests/ui/type-alias-impl-trait/indirect-recursion-issue-112047.stderr

@@ -1,14 +1,22 @@
-error[E0391]: cycle detected when computing layout of `{async block@$DIR/indirect-recursion-issue-112047.rs:23:9: 23:42}`
+error[E0391]: cycle detected when computing layout of `{async block@$DIR/indirect-recursion-issue-112047.rs:22:9: 22:42}`
+ --> $DIR/indirect-recursion-issue-112047.rs:22:22
  |
- = note: ...which requires computing layout of `core::mem::maybe_uninit::MaybeUninit<{async fn body@$DIR/indirect-recursion-issue-112047.rs:15:31: 17:2}>`...
- = note: ...which requires computing layout of `core::mem::manually_drop::ManuallyDrop<{async fn body@$DIR/indirect-recursion-issue-112047.rs:15:31: 17:2}>`...
- = note: ...which requires computing layout of `{async fn body@$DIR/indirect-recursion-issue-112047.rs:15:31: 17:2}`...
+LL | async move { recur(self).await; }
+ | ^^^^^^^^^^^^^^^^^
+ |
+ = note: ...which requires computing layout of `core::mem::maybe_uninit::MaybeUninit<{async fn body@$DIR/indirect-recursion-issue-112047.rs:14:31: 16:2}>`...
+ = note: ...which requires computing layout of `core::mem::manually_drop::ManuallyDrop<{async fn body@$DIR/indirect-recursion-issue-112047.rs:14:31: 16:2}>`...
+note: ...which requires computing layout of `{async fn body@$DIR/indirect-recursion-issue-112047.rs:14:31: 16:2}`...
+ --> $DIR/indirect-recursion-issue-112047.rs:15:5
+ |
+LL | t.recur().await;
+ | ^^^^^^^^^^^^^^^
  = note: ...which requires computing layout of `core::mem::maybe_uninit::MaybeUninit<<() as Recur>::Recur>`...
- = note: ...which requires computing layout of `core::mem::maybe_uninit::MaybeUninit<{async block@$DIR/indirect-recursion-issue-112047.rs:23:9: 23:42}>`...
- = note: ...which requires computing layout of `core::mem::manually_drop::ManuallyDrop<{async block@$DIR/indirect-recursion-issue-112047.rs:23:9: 23:42}>`...
- = note: ...which again requires computing layout of `{async block@$DIR/indirect-recursion-issue-112047.rs:23:9: 23:42}`, completing the cycle
-note: cycle used when elaborating drops for `<impl at $DIR/indirect-recursion-issue-112047.rs:19:1: 19:18>::recur`
- --> $DIR/indirect-recursion-issue-112047.rs:22:5
+ = note: ...which requires computing layout of `core::mem::maybe_uninit::MaybeUninit<{async block@$DIR/indirect-recursion-issue-112047.rs:22:9: 22:42}>`...
+ = note: ...which requires computing layout of `core::mem::manually_drop::ManuallyDrop<{async block@$DIR/indirect-recursion-issue-112047.rs:22:9: 22:42}>`...
+ = note: ...which again requires computing layout of `{async block@$DIR/indirect-recursion-issue-112047.rs:22:9: 22:42}`, completing the cycle
+note: cycle used when elaborating drops for `<impl at $DIR/indirect-recursion-issue-112047.rs:18:1: 18:18>::recur`
+ --> $DIR/indirect-recursion-issue-112047.rs:21:5
  |
 LL | fn recur(self) -> Self::Recur {
  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^