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wrap ty field of CoroutineSavedTy in EarlyBinder #163152

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1833d91
wrap ty field of CoroutineSavedTy in EarlyBinder
levyry Sep 21, 2026
d608a49
create wrapper around `CoroutineLayout`
levyry Sep 30, 2026
cd12320
make coroutine_layout query return layout wrapper
levyry Sep 30, 2026
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2 changes: 1 addition & 1 deletion compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/cpp_like.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -764,7 +764,7 @@ fn build_union_fields_for_direct_tag_coroutine<'ll, 'tcx>(
common_upvar_names,
);

let span = coroutine_layout.variant_source_info[variant_index].span;
let span = coroutine_layout.variant_source_info()[variant_index].span;
let source_info = if !span.is_dummy() {
let loc = cx.lookup_debug_loc(span.lo());
Some((file_metadata(cx, &loc.file), loc.line as c_uint))
Expand Down
8 changes: 4 additions & 4 deletions compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@ use rustc_codegen_ssa::debuginfo::{tag_base_type, wants_c_like_enum_debuginfo};
use rustc_codegen_ssa::traits::MiscCodegenMethods;
use rustc_hir::def::CtorKind;
use rustc_index::IndexSlice;
use rustc_middle::mir::CoroutineLayout;
use rustc_middle::mir::QueriedCoroutineLayout;
use rustc_middle::ty::layout::{LayoutOf, TyAndLayout};
use rustc_middle::ty::{self, AdtDef, CoroutineArgs, CoroutineArgsExt, Ty, VariantDef};
use rustc_span::{Span, Symbol, bug};
Expand Down Expand Up @@ -292,7 +292,7 @@ fn build_coroutine_variant_struct_type_di_node<'ll, 'tcx>(
variant_index: VariantIdx,
coroutine_type_and_layout: TyAndLayout<'tcx>,
coroutine_type_di_node: &'ll DIType,
coroutine_layout: &CoroutineLayout<'tcx>,
coroutine_layout: QueriedCoroutineLayout<'tcx>,
common_upvar_names: &IndexSlice<FieldIdx, Symbol>,
) -> &'ll DIType {
let variant_name = CoroutineArgs::variant_name(variant_index);
Expand Down Expand Up @@ -325,10 +325,10 @@ fn build_coroutine_variant_struct_type_di_node<'ll, 'tcx>(
// Fields that just belong to this variant/state
let state_specific_fields: SmallVec<_> = (0..variant_layout.fields.count())
.map(|field_index| {
let coroutine_saved_local = coroutine_layout.variant_fields[variant_index]
let coroutine_saved_local = coroutine_layout.variant_fields()[variant_index]
[FieldIdx::from_usize(field_index)];
let field_name_maybe =
coroutine_layout.field_tys[coroutine_saved_local].debuginfo_name;
coroutine_layout.field_tys()[coroutine_saved_local].debuginfo_name;
let field_name = field_name_maybe
.as_ref()
.map(|s| Cow::from(s.as_str()))
Expand Down
2 changes: 1 addition & 1 deletion compiler/rustc_codegen_llvm/src/debuginfo/metadata/enums/native.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -198,7 +198,7 @@ pub(super) fn build_coroutine_di_node<'ll, 'tcx>(
// with enums?
let variant_name = format!("{}", variant_index.as_usize()).into();

let span = coroutine_layout.variant_source_info[variant_index].span;
let span = coroutine_layout.variant_source_info()[variant_index].span;
let source_info = if !span.is_dummy() {
let loc = cx.lookup_debug_loc(span.lo());
Some((file_metadata(cx, &loc.file), loc.line))
Expand Down
3 changes: 2 additions & 1 deletion compiler/rustc_hir_analysis/src/check/check.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -2300,7 +2300,8 @@ fn opaque_type_cycle_error(tcx: TyCtxt<'_>, opaque_def_id: LocalDefId) -> ErrorG
&& let Some(coroutine_layout) = tcx.mir_coroutine_witnesses(closure_def_id)
{
for interior_ty in &coroutine_layout.field_tys {
label_match(interior_ty.ty, interior_ty.source_info.span);
let ty = interior_ty.ty.instantiate_identity().skip_norm_wip();
label_match(ty, interior_ty.source_info.span);
}
}
}
Expand Down
1 change: 1 addition & 0 deletions compiler/rustc_middle/src/mir/pretty.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -577,6 +577,7 @@ fn write_coroutine_layout<'tcx>(
field_tys.iter_enumerated()
{
let ignore_for_traits = if *ignore_for_traits { " (ignored for traits)" } else { "" };
let ty = ty.instantiate_identity().skip_norm_wip();
let indented_body = format!("{INDENT}{INDENT}field {field:?}: {ty}{ignore_for_traits};",);
if options.include_extra_comments {
writeln!(w, "{0:ALIGN$} // in {1}", indented_body, comment(tcx, *source_info))?;
Expand Down
60 changes: 58 additions & 2 deletions compiler/rustc_middle/src/mir/query.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@ use rustc_macros::{StableHash, TyDecodable, TyEncodable, TypeFoldable, TypeVisit
use rustc_span::{Span, Symbol};

use super::{ConstValue, SourceInfo};
use crate::ty::{self, CoroutineArgsExt, Ty};
use crate::ty::{self, CoroutineArgsExt, EarlyBinder, GenericArgsRef, Ty, TyCtxt, Unnormalized};

rustc_index::newtype_index! {
#[stable_hash]
Expand All @@ -22,7 +22,9 @@ rustc_index::newtype_index! {
#[derive(Clone, Debug, PartialEq, Eq)]
#[derive(TyEncodable, TyDecodable, StableHash, TypeFoldable, TypeVisitable)]
pub struct CoroutineSavedTy<'tcx> {
pub ty: Ty<'tcx>,
#[type_foldable(identity)]
#[type_visitable(ignore)]
Comment on lines +25 to +26

@lcnr lcnr Sep 22, 2026 •
edited by rustbot
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oh, why is this TypeFoldable?

ignoring this field is wrong. We should not type fold CoroutineSavedTy. What breaks if you remove the derive there?

View changes since the review

@levyry levyry Sep 22, 2026

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if I just remove the derive I get an error about how CoroutineLayout can't implement TypeFoldable because its fields don't implement it.

full error 
error[E0277]: the trait bound `mir::query::CoroutineSavedTy<'_>: rustc_type_ir::TypeFoldable<context::TyCtxt<'_>>` is not satisfied
  --> compiler/rustc_middle/src/mir/query.rs:39:5
   |
37 |   #[derive(TyEncodable, TyDecodable, StableHash, TypeFoldable, TypeVisitable)]
   |                                                  ------------
   |                                                  |
   |                                                  required by a bound introduced by this call
   |                                                  in this derive macro expansion
38 |   pub struct CoroutineLayout<'tcx> {
39 |       /// The type of every local stored inside the coroutine.
   |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unsatisfied trait bound
   |
  ::: /home/levy/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/synstructure-0.13.2/src/macros.rs:95:9
   |
95 | /         pub fn $derives(
96 | |             i: $crate::macros::TokenStream
97 | |         ) -> $crate::macros::TokenStream {
   | |________________________________________- in this expansion of `#[derive(TypeFoldable)]`
   |
help: the trait `rustc_type_ir::TypeFoldable<context::TyCtxt<'_>>` is not implemented for `mir::query::CoroutineSavedTy<'_>`
  --> compiler/rustc_middle/src/mir/query.rs:24:1
   |
24 | pub struct CoroutineSavedTy<'tcx> {
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   = help: the following other types implement trait `rustc_type_ir::TypeFoldable<I>`:
             `&'tcx list::RawList<(), (rustc_type_ir::OpaqueTypeKey<context::TyCtxt<'tcx>>, ty::Ty<'tcx>)>` implements `rustc_type_ir::TypeFoldable<context::TyCtxt<'tcx>>`
             `&'tcx list::RawList<(), generic_args::GenericArg<'tcx>>` implements `rustc_type_ir::TypeFoldable<context::TyCtxt<'tcx>>`
             `&'tcx list::RawList<(), rustc_span::def_id::LocalDefId>` implements `rustc_type_ir::TypeFoldable<context::TyCtxt<'tcx>>`
             `&RawList<(), Binder<TyCtxt<'tcx>, ExistentialPredicate<TyCtxt<'tcx>>>>` implements `rustc_type_ir::TypeFoldable<context::TyCtxt<'tcx>>`
             `&RawList<(), OutlivesClause<TyCtxt<'tcx>, GenericArg<'tcx>>>` implements `rustc_type_ir::TypeFoldable<context::TyCtxt<'tcx>>`
             `&'tcx list::RawList<(), syntax::ProjectionElem<mir::Local, ty::Ty<'tcx>>>` implements `rustc_type_ir::TypeFoldable<context::TyCtxt<'tcx>>`
             `&'tcx list::RawList<(), ty::Ty<'tcx>>` implements `rustc_type_ir::TypeFoldable<context::TyCtxt<'tcx>>`
             `&'tcx list::RawList<(), ty::consts::Const<'tcx>>` implements `rustc_type_ir::TypeFoldable<context::TyCtxt<'tcx>>`
           and 262 others
   = note: required for `rustc_index::IndexVec<mir::query::CoroutineSavedLocal, mir::query::CoroutineSavedTy<'_>>` to implement `rustc_type_ir::TypeFoldable<context::TyCtxt<'_>>`
   = note: the full name for the type has been written to '/home/levy/src/rust-lang/rust/build-rust-analyzer/x86_64-unknown-linux-gnu/stage1-rustc/x86_64-unknown-linux-gnu/release/build/rustc_middle/374f18fe06c7bef2/out/rustc_middle-374f18fe06c7bef2.long-type-8635111359931186326.txt'
   = note: consider using `--verbose` to print the full type name to the console

If I add a #[type_foldable(identity)] for the field_tys field which stores the CoroutineSavedTys then x check and x test tests/ui both succeed

@lcnr lcnr Sep 24, 2026

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why does CoroutineLAyout implement TypeFoldable :>

@levyry levyry Sep 24, 2026

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the chain goes like this:

CoroutineSavedTy -> CoroutineLayout -> CoroutineInfo -> Body

and if I remove it from Body I get an error at rustc_public_bridge/src/builder.rs about how Body needs to be TypeFoldable because EarlyBinder::bind requires that as a trait bound

@lcnr lcnr Sep 30, 2026

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hmm, that's kind of scuffed. Body shouldn't be TypeFoldable ideally as some of the fields of MIR bodies don't make sense after it. Fixing that is annoying and non-trivial and ignoring the EArlyBinder here is fine. Coolio

pub ty: EarlyBinder<'tcx, Ty<'tcx>>,
/// Source info corresponding to the local in the original MIR body.
pub source_info: SourceInfo,
/// Whether the local should be ignored for trait bound computations.
Expand Down Expand Up @@ -81,6 +83,60 @@ impl Debug for CoroutineLayout<'_> {
}
}

/// The result of the `coroutine_layout` function.
///
/// Wraps a regular `CoroutineLayout` with its arguments, providing accessors
/// that instantiate the stored `Ty` if necessary.
#[derive(Debug, Copy, Clone)]
pub struct QueriedCoroutineLayout<'tcx> {
layout: &'tcx CoroutineLayout<'tcx>,
args: Option<GenericArgsRef<'tcx>>,

@levyry levyry Oct 1, 2026 •
edited
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I made this an Option like you wrote previously, I assume this is so that when this is None we know to use fn instantiate_identity, but during my refactorings I didn't really see any places that would warrant instantiating this field with None. Could you let me know if I misinterpreted your comment or if I didn't instantiate this field correctly somewhere?

View changes since the review

}

impl<'tcx> QueriedCoroutineLayout<'tcx> {
pub fn new(layout: &'tcx CoroutineLayout<'tcx>, args: Option<GenericArgsRef<'tcx>>) -> Self {
Self { layout, args }
}

pub fn get_ty(
&self,
tcx: TyCtxt<'tcx>,
field: CoroutineSavedLocal,
) -> Unnormalized<'tcx, Ty<'tcx>> {
if let Some(args) = self.args {
self.layout.field_tys[field].ty.instantiate(tcx, args)
} else {
self.layout.field_tys[field].ty.instantiate_identity()
}
}

pub fn get_identity_ty(&self, field: CoroutineSavedLocal) -> Unnormalized<'tcx, Ty<'tcx>> {
self.layout.field_tys[field].ty.instantiate_identity()
}

pub fn field_tys(&self) -> &'tcx IndexVec<CoroutineSavedLocal, CoroutineSavedTy<'tcx>> {
&self.layout.field_tys
}

pub fn variant_fields(
&self,
) -> &'tcx IndexVec<VariantIdx, IndexVec<FieldIdx, CoroutineSavedLocal>> {
&self.layout.variant_fields
}

pub fn variant_source_info(&self) -> &'tcx IndexVec<VariantIdx, SourceInfo> {
&self.layout.variant_source_info
}

pub fn storage_conflicts(&self) -> &'tcx BitMatrix<CoroutineSavedLocal, CoroutineSavedLocal> {
&self.layout.storage_conflicts
}

pub fn raw_layout(self) -> &'tcx CoroutineLayout<'tcx> {
self.layout
}
}

/// The result of the `mir_const_qualif` query.
///
/// Each field (except `tainted_by_errors`) corresponds to an implementer of the `Qualif` trait in
Expand Down
21 changes: 15 additions & 6 deletions compiler/rustc_middle/src/ty/mod.rs
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Expand Up @@ -109,7 +109,9 @@ pub use self::typeck_results::{
UserTypeKind,
};
use crate::diagnostics::{OpaqueHiddenTypeMismatch, TypeMismatchReason};
use crate::mir::{Body, CoroutineLayout, CoroutineSavedLocal, MirPhase, SourceInfo};
use crate::mir::{
Body, CoroutineLayout, CoroutineSavedLocal, MirPhase, QueriedCoroutineLayout, SourceInfo,
};
use crate::query::{IntoQueryKey, Providers};
use crate::ty;
use crate::ty::codec::{TyDecoder, TyEncoder};
Expand Down Expand Up @@ -1942,13 +1944,15 @@ impl<'tcx> TyCtxt<'tcx> {
self,
def_id: DefId,
args: GenericArgsRef<'tcx>,
) -> Result<&'tcx CoroutineLayout<'tcx>, &'tcx LayoutError<'tcx>> {
) -> Result<QueriedCoroutineLayout<'tcx>, &'tcx LayoutError<'tcx>> {
let coroutine_kind_ty = args.as_coroutine().kind_ty();
let mir = self.optimized_mir(def_id);
let ty = || Ty::new_coroutine(self, def_id, args);
// Regular coroutine
if coroutine_kind_ty.is_unit() {
mir.coroutine_layout_raw().ok_or_else(|| self.layout_error(LayoutError::Unknown(ty())))
mir.coroutine_layout_raw()
.map(|layout| QueriedCoroutineLayout::new(layout, Some(args)))
.ok_or_else(|| self.layout_error(LayoutError::Unknown(ty())))
} else {
// If we have a `Coroutine` that comes from an coroutine-closure,
// then it may be a by-move or by-ref body.
Expand All @@ -1962,6 +1966,7 @@ impl<'tcx> TyCtxt<'tcx> {
// a by-ref coroutine.
if identity_kind_ty == coroutine_kind_ty {
mir.coroutine_layout_raw()
.map(|layout| QueriedCoroutineLayout::new(layout, Some(args)))
.ok_or_else(|| self.layout_error(LayoutError::Unknown(ty())))
} else {
assert_matches!(coroutine_kind_ty.to_opt_closure_kind(), Some(ClosureKind::FnOnce));
Expand All @@ -1971,6 +1976,7 @@ impl<'tcx> TyCtxt<'tcx> {
);
self.optimized_mir(self.coroutine_by_move_body_def_id(def_id))
.coroutine_layout_raw()
.map(|layout| QueriedCoroutineLayout::new(layout, Some(args)))
.ok_or_else(|| self.layout_error(LayoutError::Unknown(ty())))
}
}
Expand All @@ -1983,14 +1989,15 @@ impl<'tcx> TyCtxt<'tcx> {
self,
def_id: DefId,
args: GenericArgsRef<'tcx>,
) -> Result<&'tcx CoroutineLayout<'tcx>, &'tcx LayoutError<'tcx>> {
) -> Result<QueriedCoroutineLayout<'tcx>, &'tcx LayoutError<'tcx>> {
let ty = || Ty::new_coroutine(self, def_id, args);
if args[0].has_placeholders() || args[0].has_non_region_param() {
return Err(self.layout_error(LayoutError::TooGeneric(ty())));
}
let instance = ShimKind::AsyncDropGlue(def_id, Ty::new_coroutine(self, def_id, args));
self.mir_shims(instance)
.coroutine_layout_raw()
.map(|layout| QueriedCoroutineLayout::new(layout, Some(args)))
.ok_or_else(|| self.layout_error(LayoutError::Unknown(ty())))
}

Expand All @@ -2000,7 +2007,7 @@ impl<'tcx> TyCtxt<'tcx> {
self,
def_id: DefId,
args: GenericArgsRef<'tcx>,
) -> Result<&'tcx CoroutineLayout<'tcx>, &'tcx LayoutError<'tcx>> {
) -> Result<QueriedCoroutineLayout<'tcx>, &'tcx LayoutError<'tcx>> {
if self.is_async_drop_in_place_coroutine(def_id) {
// layout of `async_drop_in_place<T>::{closure}` in case,
// when T is a coroutine, contains this internal coroutine's ptr in upvars
Expand All @@ -2021,7 +2028,9 @@ impl<'tcx> TyCtxt<'tcx> {
variant_source_info,
storage_conflicts: BitMatrix::new(0, 0),
};
return Ok(self.arena.alloc(proxy_layout));
let layout = self.arena.alloc(proxy_layout);
let queried_layout = QueriedCoroutineLayout::new(layout, Some(args));
return Ok(queried_layout);
} else {
self.async_drop_coroutine_layout(def_id, args)
}
Expand Down
12 changes: 6 additions & 6 deletions compiler/rustc_middle/src/ty/sty.rs
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Expand Up @@ -101,7 +101,8 @@ impl<'tcx> ty::CoroutineArgs<TyCtxt<'tcx>> {
#[inline]
fn variant_range(&self, def_id: DefId, tcx: TyCtxt<'tcx>) -> Range<VariantIdx> {
// FIXME requires optimized MIR
FIRST_VARIANT..tcx.coroutine_layout(def_id, self.args).unwrap().variant_fields.next_index()
FIRST_VARIANT
..tcx.coroutine_layout(def_id, self.args).unwrap().variant_fields().next_index()
}

/// The discriminant for the given variant. Panics if the `variant_index` is
Expand Down Expand Up @@ -162,14 +163,13 @@ impl<'tcx> ty::CoroutineArgs<TyCtxt<'tcx>> {
tcx: TyCtxt<'tcx>,
) -> impl Iterator<Item: Iterator<Item = Ty<'tcx>>> {
let layout = tcx.coroutine_layout(def_id, self.args).unwrap();
layout.variant_fields.iter().map(move |variant| {
layout.variant_fields().iter().map(move |variant| {
variant.iter().map(move |field| {
if tcx.is_async_drop_in_place_coroutine(def_id) {
layout.field_tys[*field].ty
// FIXME(async_drop): this needs a comment for why its correct
layout.get_identity_ty(*field).skip_norm_wip()

@levyry levyry Oct 1, 2026 •
edited by rustbot
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This function is only used once here, and I am not sure if it's really needed or not, as ideally get_ty would handle the identity initialization as well, but for this first version of QueriedCoroutineLayout I wanted to include a more personalized API, which I can revise later ^^

View changes since the review

} else {
ty::EarlyBinder::bind(tcx, layout.field_tys[*field].ty)
.instantiate(tcx, self.args)
.skip_norm_wip()
layout.get_ty(tcx, *field).skip_norm_wip()
}
})
})
Expand Down
25 changes: 17 additions & 8 deletions compiler/rustc_mir_transform/src/coroutine/layout.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -35,7 +35,9 @@ use rustc_infer::traits::TraitErrors;
use rustc_lint_defs::builtin::MUST_NOT_SUSPEND;
use rustc_middle::mir::*;
use rustc_middle::ty::consts::ConstExt;
use rustc_middle::ty::{self, CoroutineArgs, CoroutineArgsExt, Ty, TyCtxt, TypingMode};
use rustc_middle::ty::{
self, CoroutineArgs, CoroutineArgsExt, EarlyBinder, Ty, TyCtxt, TypingMode,
};
use rustc_mir_dataflow::impls::{
MaybeBorrowedLocals, MaybeLiveLocals, MaybeRequiresStorage, MaybeStorageLive,
always_storage_live_locals,
Expand Down Expand Up @@ -341,8 +343,9 @@ impl StorageConflictVisitor<'_> {
}
}

#[tracing::instrument(level = "trace", skip(liveness, body))]
#[tracing::instrument(level = "trace", skip(tcx, liveness, body))]
pub(super) fn compute_layout<'tcx>(
tcx: TyCtxt<'tcx>,
liveness: LivenessInfo,
body: &Body<'tcx>,
) -> (
Expand Down Expand Up @@ -383,7 +386,7 @@ pub(super) fn compute_layout<'tcx>(
};

CoroutineSavedTy {
ty: decl.ty,
ty: EarlyBinder::bind(tcx, decl.ty),
source_info: decl.source_info,
ignore_for_traits,
// Will be set later when walking debuginfo.
Expand Down Expand Up @@ -426,7 +429,11 @@ pub(super) fn compute_layout<'tcx>(
// just use the first one here. That's fine; fields do not move
// around inside coroutines, so it doesn't matter which variant
// index we access them by.
remap[reverse_local_map[saved_local]] = Some((tys[saved_local].ty, variant_index, idx));
remap[reverse_local_map[saved_local]] = Some((
tys[saved_local].ty.instantiate_identity().skip_norm_wip(),
variant_index,
idx,
));
}
variant_source_info.push(source_info_at_suspension_point);
}
Expand Down Expand Up @@ -479,7 +486,7 @@ pub(crate) fn mir_coroutine_witnesses<'tcx>(
// Extract locals which are live across suspension point into `layout`
// `remap` gives a mapping from local indices onto coroutine struct indices
// `storage_liveness` tells us which locals have live storage at suspension points
let (_, coroutine_layout, _) = compute_layout(liveness_info, body);
let (_, coroutine_layout, _) = compute_layout(tcx, liveness_info, body);

check_suspend_tys(tcx, &coroutine_layout, body);
check_field_tys_sized(tcx, &coroutine_layout, def_id);
Expand Down Expand Up @@ -514,7 +521,7 @@ fn check_field_tys_sized<'tcx>(
ObligationCauseCode::SizedCoroutineInterior(def_id),
),
param_env,
field_ty.ty,
field_ty.ty.instantiate_identity().skip_norm_wip(),
tcx.require_lang_item(LangItem::Sized, field_ty.source_info.span),
);
}
Expand All @@ -537,14 +544,16 @@ fn check_suspend_tys<'tcx>(tcx: TyCtxt<'tcx>, layout: &CoroutineLayout<'tcx>, bo
let decl = &layout.field_tys[local];
debug!(?decl);

if !decl.ignore_for_traits && linted_tys.insert(decl.ty) {
let ty = decl.ty.instantiate_identity().skip_norm_wip();

if !decl.ignore_for_traits && linted_tys.insert(ty) {
let Some(hir_id) = decl.source_info.scope.lint_root(&body.source_scopes) else {
continue;
};

check_must_not_suspend_ty(
tcx,
decl.ty,
ty,
hir_id,
SuspendCheckData {
source_span: decl.source_info.span,
Expand Down
2 changes: 1 addition & 1 deletion compiler/rustc_mir_transform/src/coroutine/mod.rs
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Expand Up @@ -1119,7 +1119,7 @@ impl<'tcx> crate::MirPass<'tcx> for StateTransform {
// Extract locals which are live across suspension point into `layout`
// `remap` gives a mapping from local indices onto coroutine struct indices
// `storage_liveness` tells us which locals have live storage at suspension points
let (remap, layout, storage_liveness) = compute_layout(liveness_info, body);
let (remap, layout, storage_liveness) = compute_layout(tcx, liveness_info, body);

let can_return = can_return(tcx, body, body.typing_env(tcx));

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18 changes: 11 additions & 7 deletions compiler/rustc_mir_transform/src/validate.rs
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Expand Up @@ -766,9 +766,12 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
// since we may be in the process of computing this MIR in the
// first place.
let layout = if def_id == self.caller_body.source.def_id() {
self.caller_body
.coroutine_layout_raw()
.or_else(|| self.tcx.coroutine_layout(def_id, args).ok())
self.caller_body.coroutine_layout_raw().or_else(|| {
self.tcx
.coroutine_layout(def_id, args)
.ok()
.map(|queried| queried.raw_layout())

@levyry levyry Oct 1, 2026 •
edited by rustbot
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raw_layout is only used here in validate.rs. I could remove this fn rewrite this branch to use QueriedCoroutineLayout if you'd like, but it seemed messier to me

View changes since the review

@levyry levyry Oct 1, 2026

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To clarify the messiness: in this branch we have a &'a CoroutineLayout instead of a &'tcx CoroutineLayout, so it seems to me the only way to work with QueriedCoroutineLayout directly here is to do:

pub struct QueriedCoroutineLayout<'a, 'tcx> {
    layout: &'a CoroutineLayout<'tcx>,
    args: Option<GenericArgsRef<'tcx>>,
}

which seemed undesirable to me.

})
} else if self.tcx.needs_coroutine_by_move_body_def_id(def_id)
&& let ty::ClosureKind::FnOnce =
args.as_coroutine().kind_ty().to_opt_closure_kind().unwrap()
Expand All @@ -778,7 +781,10 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
// Same if this is the by-move body of a coroutine-closure.
self.caller_body.coroutine_layout_raw()
} else {
self.tcx.coroutine_layout(def_id, args).ok()
self.tcx
.coroutine_layout(def_id, args)
.ok()
.map(|queried| queried.raw_layout())
};

let Some(layout) = layout else {
Expand All @@ -802,9 +808,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> {
return;
};

ty::EarlyBinder::bind(self.tcx, f_ty.ty)
.instantiate(self.tcx, args)
.skip_norm_wip()
f_ty.ty.instantiate(self.tcx, args).skip_norm_wip()
} else if let Some(&f_ty) = args.as_coroutine().upvar_tys().get(f.index()) {
f_ty
} else {
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3 changes: 2 additions & 1 deletion compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
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Expand Up @@ -3494,7 +3494,8 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
for &local in variant {
let decl = &coroutine_info.field_tys[local];
debug!(?decl);
if ty_matches(ty::Binder::dummy(decl.ty)) && !decl.ignore_for_traits {
let ty = decl.ty.instantiate_identity().skip_norm_wip();
if ty_matches(ty::Binder::dummy(ty)) && !decl.ignore_for_traits {
interior_or_upvar_span = Some(CoroutineInteriorOrUpvar::Interior(
decl.source_info.span,
Some((source_info.span, from_awaited_ty)),
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