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Exhaustively match CoroutineKind in fn_sig_for_fn_abi
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@bjorn3
bjorn3 committed Nov 23, 2023
1 parent b7bc8d5 commit 3e5b0f5
Showing 1 changed file with 70 additions and 60 deletions.
130 changes: 70 additions & 60 deletions compiler/rustc_ty_utils/src/abi.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -98,6 +98,7 @@ fn fn_sig_for_fn_abi<'tcx>(
)
}
ty::Coroutine(did, args, _) => {
let coroutine_kind = tcx.coroutine_kind(did);
let sig = args.as_coroutine().poly_sig();

let bound_vars = tcx.mk_bound_variable_kinds_from_iter(
Expand All @@ -112,74 +113,83 @@ fn fn_sig_for_fn_abi<'tcx>(
let pin_did = tcx.require_lang_item(LangItem::Pin, None);
let pin_adt_ref = tcx.adt_def(pin_did);
let pin_args = tcx.mk_args(&[env_ty.into()]);
let env_ty = if tcx.coroutine_is_gen(did) {
// Iterator::next doesn't accept a pinned argument,
// unlike for all other coroutine kinds.
env_ty
} else {
Ty::new_adt(tcx, pin_adt_ref, pin_args)
let env_ty = match coroutine_kind {
hir::CoroutineKind::Gen(_) => {
// Iterator::next doesn't accept a pinned argument,
// unlike for all other coroutine kinds.
env_ty
}
hir::CoroutineKind::Async | hir::CoroutineKind::Coroutine => {
Ty::new_adt(tcx, pin_adt_ref, pin_args)
}
};

let sig = sig.skip_binder();
// The `FnSig` and the `ret_ty` here is for a coroutines main
// `Coroutine::resume(...) -> CoroutineState` function in case we
// have an ordinary coroutine, or the `Future::poll(...) -> Poll`
// function in case this is a special coroutine backing an async construct.
let (resume_ty, ret_ty) = if tcx.coroutine_is_async(did) {
// The signature should be `Future::poll(_, &mut Context<'_>) -> Poll<Output>`
assert_eq!(sig.yield_ty, tcx.types.unit);

let poll_did = tcx.require_lang_item(LangItem::Poll, None);
let poll_adt_ref = tcx.adt_def(poll_did);
let poll_args = tcx.mk_args(&[sig.return_ty.into()]);
let ret_ty = Ty::new_adt(tcx, poll_adt_ref, poll_args);

// We have to replace the `ResumeTy` that is used for type and borrow checking
// with `&mut Context<'_>` which is used in codegen.
#[cfg(debug_assertions)]
{
if let ty::Adt(resume_ty_adt, _) = sig.resume_ty.kind() {
let expected_adt =
tcx.adt_def(tcx.require_lang_item(LangItem::ResumeTy, None));
assert_eq!(*resume_ty_adt, expected_adt);
} else {
panic!("expected `ResumeTy`, found `{:?}`", sig.resume_ty);
};
}
let context_mut_ref = Ty::new_task_context(tcx);

(Some(context_mut_ref), ret_ty)
} else if tcx.coroutine_is_gen(did) {
// The signature should be `Iterator::next(_) -> Option<Yield>`
let option_did = tcx.require_lang_item(LangItem::Option, None);
let option_adt_ref = tcx.adt_def(option_did);
let option_args = tcx.mk_args(&[sig.yield_ty.into()]);
let ret_ty = Ty::new_adt(tcx, option_adt_ref, option_args);

assert_eq!(sig.return_ty, tcx.types.unit);
// have an ordinary coroutine, the `Future::poll(...) -> Poll`
// function in case this is a special coroutine backing an async construct
// or the `Iterator::next(...) -> Option` function in case this is a
// special coroutine backing a gen construct.
let (resume_ty, ret_ty) = match coroutine_kind {
hir::CoroutineKind::Async(_) => {
// The signature should be `Future::poll(_, &mut Context<'_>) -> Poll<Output>`
assert_eq!(sig.yield_ty, tcx.types.unit);

let poll_did = tcx.require_lang_item(LangItem::Poll, None);
let poll_adt_ref = tcx.adt_def(poll_did);
let poll_args = tcx.mk_args(&[sig.return_ty.into()]);
let ret_ty = Ty::new_adt(tcx, poll_adt_ref, poll_args);

// We have to replace the `ResumeTy` that is used for type and borrow checking
// with `&mut Context<'_>` which is used in codegen.
#[cfg(debug_assertions)]
{
if let ty::Adt(resume_ty_adt, _) = sig.resume_ty.kind() {
let expected_adt =
tcx.adt_def(tcx.require_lang_item(LangItem::ResumeTy, None));
assert_eq!(*resume_ty_adt, expected_adt);
} else {
panic!("expected `ResumeTy`, found `{:?}`", sig.resume_ty);
};
}
let context_mut_ref = Ty::new_task_context(tcx);

// We have to replace the `ResumeTy` that is used for type and borrow checking
// with `()` which is used in codegen.
#[cfg(debug_assertions)]
{
if let ty::Adt(resume_ty_adt, _) = sig.resume_ty.kind() {
let expected_adt =
tcx.adt_def(tcx.require_lang_item(LangItem::ResumeTy, None));
assert_eq!(*resume_ty_adt, expected_adt);
} else {
panic!("expected `ResumeTy`, found `{:?}`", sig.resume_ty);
};
(Some(context_mut_ref), ret_ty)
}
hir::CoroutineKind::Gen(_) => {
// The signature should be `Iterator::next(_) -> Option<Yield>`
let option_did = tcx.require_lang_item(LangItem::Option, None);
let option_adt_ref = tcx.adt_def(option_did);
let option_args = tcx.mk_args(&[sig.yield_ty.into()]);
let ret_ty = Ty::new_adt(tcx, option_adt_ref, option_args);

assert_eq!(sig.return_ty, tcx.types.unit);

// We have to replace the `ResumeTy` that is used for type and borrow checking
// with `()` which is used in codegen.
#[cfg(debug_assertions)]
{
if let ty::Adt(resume_ty_adt, _) = sig.resume_ty.kind() {
let expected_adt =
tcx.adt_def(tcx.require_lang_item(LangItem::ResumeTy, None));
assert_eq!(*resume_ty_adt, expected_adt);
} else {
panic!("expected `ResumeTy`, found `{:?}`", sig.resume_ty);
};
}

(None, ret_ty)
} else {
// The signature should be `Coroutine::resume(_, Resume) -> CoroutineState<Yield, Return>`
let state_did = tcx.require_lang_item(LangItem::CoroutineState, None);
let state_adt_ref = tcx.adt_def(state_did);
let state_args = tcx.mk_args(&[sig.yield_ty.into(), sig.return_ty.into()]);
let ret_ty = Ty::new_adt(tcx, state_adt_ref, state_args);

(Some(sig.resume_ty), ret_ty)
(None, ret_ty)
}
hir::CoroutineKind::Coroutine => {
// The signature should be `Coroutine::resume(_, Resume) -> CoroutineState<Yield, Return>`
let state_did = tcx.require_lang_item(LangItem::CoroutineState, None);
let state_adt_ref = tcx.adt_def(state_did);
let state_args = tcx.mk_args(&[sig.yield_ty.into(), sig.return_ty.into()]);
let ret_ty = Ty::new_adt(tcx, state_adt_ref, state_args);

(Some(sig.resume_ty), ret_ty)
}
};

let fn_sig = if let Some(resume_ty) = resume_ty {
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