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Consolidate logic around resolving built-in coroutine trait impls

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This commit is contained in:
Michael Goulet 2024-01-19 21:28:37 +00:00
parent 32ec40c685
commit f2ef88ba06
5 changed files with 56 additions and 58 deletions
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59
compiler/rustc_ty_utils/src/instance.rs
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@ -245,63 +245,6 @@ fn resolve_associated_item<'tcx>(
span: tcx.def_span(trait_item_id),
})
}
} else if Some(trait_ref.def_id) == lang_items.future_trait() {
let ty::Coroutine(coroutine_def_id, args) = *rcvr_args.type_at(0).kind() else {
bug!()
};
if Some(trait_item_id) == tcx.lang_items().future_poll_fn() {
// `Future::poll` is generated by the compiler.
Some(Instance { def: ty::InstanceDef::Item(coroutine_def_id), args: args })
} else {
// All other methods are default methods of the `Future` trait.
// (this assumes that `ImplSource::Builtin` is only used for methods on `Future`)
debug_assert!(tcx.defaultness(trait_item_id).has_value());
Some(Instance::new(trait_item_id, rcvr_args))
}
} else if Some(trait_ref.def_id) == lang_items.iterator_trait() {
let ty::Coroutine(coroutine_def_id, args) = *rcvr_args.type_at(0).kind() else {
bug!()
};
if Some(trait_item_id) == tcx.lang_items().next_fn() {
// `Iterator::next` is generated by the compiler.
Some(Instance { def: ty::InstanceDef::Item(coroutine_def_id), args })
} else {
// All other methods are default methods of the `Iterator` trait.
// (this assumes that `ImplSource::Builtin` is only used for methods on `Iterator`)
debug_assert!(tcx.defaultness(trait_item_id).has_value());
Some(Instance::new(trait_item_id, rcvr_args))
}
} else if Some(trait_ref.def_id) == lang_items.async_iterator_trait() {
let ty::Coroutine(coroutine_def_id, args) = *rcvr_args.type_at(0).kind() else {
bug!()
};
if cfg!(debug_assertions) && tcx.item_name(trait_item_id) != sym::poll_next {
span_bug!(
tcx.def_span(coroutine_def_id),
"no definition for `{trait_ref}::{}` for built-in coroutine type",
tcx.item_name(trait_item_id)
)
}
// `AsyncIterator::poll_next` is generated by the compiler.
Some(Instance { def: ty::InstanceDef::Item(coroutine_def_id), args })
} else if Some(trait_ref.def_id) == lang_items.coroutine_trait() {
let ty::Coroutine(coroutine_def_id, args) = *rcvr_args.type_at(0).kind() else {
bug!()
};
if cfg!(debug_assertions) && tcx.item_name(trait_item_id) != sym::resume {
// For compiler developers who'd like to add new items to `Coroutine`,
// you either need to generate a shim body, or perhaps return
// `InstanceDef::Item` pointing to a trait default method body if
// it is given a default implementation by the trait.
span_bug!(
tcx.def_span(coroutine_def_id),
"no definition for `{trait_ref}::{}` for built-in coroutine type",
tcx.item_name(trait_item_id)
)
}
Some(Instance { def: ty::InstanceDef::Item(coroutine_def_id), args })
} else if tcx.fn_trait_kind_from_def_id(trait_ref.def_id).is_some() {
// FIXME: This doesn't check for malformed libcore that defines, e.g.,
// `trait Fn { fn call_once(&self) { .. } }`. This is mostly for extension
@ -334,7 +277,7 @@ fn resolve_associated_item<'tcx>(
),
}
} else {
None
Instance::try_resolve_item_for_coroutine(tcx, trait_item_id, trait_id, rcvr_args)
}
}
traits::ImplSource::Param(..)