bjoernager/rust
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Remove opaque type obligation and just register opaque types as they are encountered.

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This also registers obligations for the hidden type immediately.
This commit is contained in:
Oli Scherer 2022-02-17 13:28:06 +00:00
parent 86e1860495
commit 1163aa7e72
60 changed files with 290 additions and 311 deletions
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23
compiler/rustc_infer/src/infer/canonical/query_response.rs
View file

@ -22,6 +22,7 @@ use rustc_data_structures::captures::Captures;
use rustc_index::vec::Idx;
use rustc_index::vec::IndexVec;
use rustc_middle::arena::ArenaAllocatable;
use rustc_middle::ty::error::TypeError;
use rustc_middle::ty::fold::TypeFoldable;
use rustc_middle::ty::relate::TypeRelation;
use rustc_middle::ty::subst::{GenericArg, GenericArgKind};
@ -499,7 +500,7 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
for &(a, b) in &query_response.value.opaque_types {
let a = substitute_value(self.tcx, &result_subst, a);
let b = substitute_value(self.tcx, &result_subst, b);
obligations.extend(self.handle_opaque_type(a, b, cause, param_env)?.obligations);
obligations.extend(self.handle_opaque_type(a, b, true, cause, param_env)?.obligations);
}
Ok(InferOk { value: result_subst, obligations })
@ -718,13 +719,17 @@ impl<'tcx> TypeRelatingDelegate<'tcx> for QueryTypeRelatingDelegate<'_, 'tcx> {
true
}
fn register_opaque_type(&mut self, a: Ty<'tcx>, b: Ty<'tcx>, a_is_expected: bool) {
self.obligations.push(self.infcx.opaque_ty_obligation(
a,
b,
a_is_expected,
self.param_env,
self.cause.clone(),
));
fn register_opaque_type(
&mut self,
a: Ty<'tcx>,
b: Ty<'tcx>,
a_is_expected: bool,
) -> Result<(), TypeError<'tcx>> {
self.obligations.extend(
self.infcx
.handle_opaque_type(a, b, a_is_expected, &self.cause, self.param_env)?
.obligations,
);
Ok(())
}
}

18
compiler/rustc_infer/src/infer/equate.rs
View file

@ -98,13 +98,17 @@ impl<'tcx> TypeRelation<'tcx> for Equate<'_, '_, 'tcx> {
(&ty::Opaque(did, ..), _) | (_, &ty::Opaque(did, ..))
if self.fields.define_opaque_types && did.is_local() =>
{
self.fields.obligations.push(infcx.opaque_ty_obligation(
a,
b,
self.a_is_expected(),
self.param_env(),
self.fields.trace.cause.clone(),
));
self.fields.obligations.extend(
infcx
.handle_opaque_type(
a,
b,
self.a_is_expected(),
&self.fields.trace.cause,
self.param_env(),
)?
.obligations,
);
}
_ => {

12
compiler/rustc_infer/src/infer/lattice.rs
View file

@ -111,13 +111,11 @@ where
(&ty::Opaque(did, ..), _) | (_, &ty::Opaque(did, ..))
if this.define_opaque_types() && did.is_local() =>
{
this.add_obligations(vec![infcx.opaque_ty_obligation(
a,
b,
this.a_is_expected(),
this.param_env(),
this.cause().clone(),
)]);
this.add_obligations(
infcx
.handle_opaque_type(a, b, this.a_is_expected(), this.cause(), this.param_env())?
.obligations,
);
Ok(a)
}

9
compiler/rustc_infer/src/infer/nll_relate/mod.rs
View file

@ -91,7 +91,12 @@ pub trait TypeRelatingDelegate<'tcx> {
);
fn const_equate(&mut self, a: ty::Const<'tcx>, b: ty::Const<'tcx>);
fn register_opaque_type(&mut self, a: Ty<'tcx>, b: Ty<'tcx>, a_is_expected: bool);
fn register_opaque_type(
&mut self,
a: Ty<'tcx>,
b: Ty<'tcx>,
a_is_expected: bool,
) -> Result<(), TypeError<'tcx>>;
/// Creates a new universe index. Used when instantiating placeholders.
fn create_next_universe(&mut self) -> ty::UniverseIndex;
@ -590,7 +595,7 @@ where
(_, &ty::Opaque(..)) => (generalize(a, true)?, b),
_ => unreachable!(),
};
self.delegate.register_opaque_type(a, b, true);
self.delegate.register_opaque_type(a, b, true)?;
trace!(a = ?a.kind(), b = ?b.kind(), "opaque type instantiated");
Ok(a)
}

112
compiler/rustc_infer/src/infer/opaque_types.rs
View file

@ -1,5 +1,5 @@
use crate::infer::{InferCtxt, InferOk};
use crate::traits::{self, PredicateObligation};
use crate::traits;
use hir::def_id::{DefId, LocalDefId};
use hir::OpaqueTyOrigin;
use rustc_data_structures::sync::Lrc;
@ -42,25 +42,25 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
&self,
a: Ty<'tcx>,
b: Ty<'tcx>,
a_is_expected: bool,
cause: &ObligationCause<'tcx>,
param_env: ty::ParamEnv<'tcx>,
) -> InferResult<'tcx, ()> {
if a.references_error() || b.references_error() {
return Ok(InferOk { value: (), obligations: vec![] });
}
if self.defining_use_anchor.is_some() {
let process = |a: Ty<'tcx>, b: Ty<'tcx>| match *a.kind() {
ty::Opaque(def_id, substs) => {
if let ty::Opaque(did2, _) = *b.kind() {
// We could accept this, but there are various ways to handle this situation, and we don't
// want to make a decision on it right now. Likely this case is so super rare anyway, that
// no one encounters it in practice.
// It does occur however in `fn fut() -> impl Future<Output = i32> { async { 42 } }`,
// where it is of no concern, so we only check for TAITs.
if let Some(OpaqueTyOrigin::TyAlias) =
self.opaque_type_origin(did2, cause.span)
{
self.tcx
let (a, b) = if a_is_expected { (a, b) } else { (b, a) };
let process = |a: Ty<'tcx>, b: Ty<'tcx>| match *a.kind() {
ty::Opaque(def_id, substs) => {
if let ty::Opaque(did2, _) = *b.kind() {
// We could accept this, but there are various ways to handle this situation, and we don't
// want to make a decision on it right now. Likely this case is so super rare anyway, that
// no one encounters it in practice.
// It does occur however in `fn fut() -> impl Future<Output = i32> { async { 42 } }`,
// where it is of no concern, so we only check for TAITs.
if let Some(OpaqueTyOrigin::TyAlias) = self.opaque_type_origin(did2, cause.span)
{
self.tcx
.sess
.struct_span_err(
cause.span,
@ -76,13 +76,14 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
"opaque type being used as hidden type",
)
.emit();
}
}
Some(self.register_hidden_type(
OpaqueTypeKey { def_id, substs },
cause.clone(),
param_env,
b,
}
Some(self.register_hidden_type(
OpaqueTypeKey { def_id, substs },
cause.clone(),
param_env,
b,
if self.defining_use_anchor.is_some() {
// Check that this is `impl Trait` type is
// declared by `parent_def_id` -- i.e., one whose
// value we are inferring. At present, this is
@ -117,47 +118,28 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
// let x = || foo(); // returns the Opaque assoc with `foo`
// }
// ```
self.opaque_type_origin(def_id, cause.span)?,
))
}
_ => None,
};
if let Some(res) = process(a, b) {
res
} else if let Some(res) = process(b, a) {
res
} else {
// Rerun equality check, but this time error out due to
// different types.
match self.at(cause, param_env).define_opaque_types(false).eq(a, b) {
Ok(_) => span_bug!(
cause.span,
"opaque types are never equal to anything but themselves: {:#?}",
(a.kind(), b.kind())
),
Err(e) => Err(e),
}
self.opaque_type_origin(def_id, cause.span)?
} else {
self.opaque_ty_origin_unchecked(def_id, cause.span)
},
))
}
_ => None,
};
if let Some(res) = process(a, b) {
res
} else if let Some(res) = process(b, a) {
res
} else {
let (opaque_type, hidden_ty) = match (a.kind(), b.kind()) {
(ty::Opaque(..), _) => (a, b),
(_, ty::Opaque(..)) => (b, a),
types => span_bug!(
// Rerun equality check, but this time error out due to
// different types.
match self.at(cause, param_env).define_opaque_types(false).eq(a, b) {
Ok(_) => span_bug!(
cause.span,
"opaque type obligations only work for opaque types: {:#?}",
types
"opaque types are never equal to anything but themselves: {:#?}",
(a.kind(), b.kind())
),
};
let key = opaque_type.expect_opaque_type();
let origin = self.opaque_ty_origin_unchecked(key.def_id, cause.span);
let prev = self.inner.borrow_mut().opaque_types().register(
key,
OpaqueHiddenType { ty: hidden_ty, span: cause.span },
origin,
);
match prev {
Some(prev) => self.at(cause, param_env).eq(prev, hidden_ty),
None => Ok(InferOk { value: (), obligations: vec![] }),
Err(e) => Err(e),
}
}
}
@ -363,22 +345,6 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
});
}
pub fn opaque_ty_obligation(
&self,
a: Ty<'tcx>,
b: Ty<'tcx>,
a_is_expected: bool,
param_env: ty::ParamEnv<'tcx>,
cause: ObligationCause<'tcx>,
) -> PredicateObligation<'tcx> {
let (a, b) = if a_is_expected { (a, b) } else { (b, a) };
PredicateObligation::new(
cause,
param_env,
self.tcx.mk_predicate(ty::Binder::dummy(ty::PredicateKind::OpaqueType(a, b))),
)
}
#[instrument(skip(self), level = "trace")]
pub fn opaque_type_origin(&self, opaque_def_id: DefId, span: Span) -> Option<OpaqueTyOrigin> {
let def_id = opaque_def_id.as_local()?;

1
compiler/rustc_infer/src/infer/outlives/mod.rs
View file

@ -28,7 +28,6 @@ pub fn explicit_outlives_bounds<'tcx>(
| ty::PredicateKind::TypeOutlives(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..)
| ty::PredicateKind::OpaqueType(..)
| ty::PredicateKind::TypeWellFormedFromEnv(..) => None,
ty::PredicateKind::RegionOutlives(ty::OutlivesPredicate(r_a, r_b)) => {
Some(OutlivesBound::RegionSubRegion(r_b, r_a))

12
compiler/rustc_infer/src/infer/sub.rs
View file

@ -146,13 +146,11 @@ impl<'tcx> TypeRelation<'tcx> for Sub<'_, '_, 'tcx> {
(_, &ty::Opaque(..)) => (generalize(a, false)?, b),
_ => unreachable!(),
};
self.fields.obligations.push(infcx.opaque_ty_obligation(
a,
b,
true,
self.param_env(),
self.fields.trace.cause.clone(),
));
self.fields.obligations.extend(
infcx
.handle_opaque_type(a, b, true, &self.fields.trace.cause, self.param_env())?
.obligations,
);
Ok(a)
}

3
compiler/rustc_infer/src/traits/util.rs
View file

@ -167,9 +167,6 @@ impl<'tcx> Elaborator<'tcx> {
// Currently, we do not elaborate WF predicates,
// although we easily could.
}
ty::PredicateKind::OpaqueType(..) => {
todo!("{:#?}", obligation)
}
ty::PredicateKind::ObjectSafe(..) => {
// Currently, we do not elaborate object-safe
// predicates.