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Auto merge of #73503 - lcnr:forall-predicate-what-and-why-2, r=nikomatsakis

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convert higher ranked `Predicate`s to `PredicateKind::ForAll`

implements step 2 of https://github.com/rust-lang/compiler-team/issues/285
r? @nikomatsakis
This commit is contained in:
bors 2020-07-27 20:16:36 +00:00
commit 76e83339bb
61 changed files with 1274 additions and 1156 deletions
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45
src/librustc_infer/infer/canonical/query_response.rs
View file

@ -525,28 +525,25 @@ impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
result_subst: &'a CanonicalVarValues<'tcx>,
) -> impl Iterator<Item = PredicateObligation<'tcx>> + 'a + Captures<'tcx> {
unsubstituted_region_constraints.iter().map(move |constraint| {
let constraint = substitute_value(self.tcx, result_subst, constraint);
let ty::OutlivesPredicate(k1, r2) = constraint.skip_binder(); // restored below
let ty::OutlivesPredicate(k1, r2) =
substitute_value(self.tcx, result_subst, constraint).skip_binder();
Obligation::new(
cause.clone(),
param_env,
match k1.unpack() {
GenericArgKind::Lifetime(r1) => ty::PredicateKind::RegionOutlives(
ty::Binder::bind(ty::OutlivesPredicate(r1, r2)),
)
.to_predicate(self.tcx),
GenericArgKind::Type(t1) => ty::PredicateKind::TypeOutlives(ty::Binder::bind(
ty::OutlivesPredicate(t1, r2),
))
.to_predicate(self.tcx),
GenericArgKind::Const(..) => {
// Consts cannot outlive one another, so we don't expect to
// ecounter this branch.
span_bug!(cause.span, "unexpected const outlives {:?}", constraint);
}
},
)
let predicate = match k1.unpack() {
GenericArgKind::Lifetime(r1) => {
ty::PredicateAtom::RegionOutlives(ty::OutlivesPredicate(r1, r2))
}
GenericArgKind::Type(t1) => {
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(t1, r2))
}
GenericArgKind::Const(..) => {
// Consts cannot outlive one another, so we don't expect to
// encounter this branch.
span_bug!(cause.span, "unexpected const outlives {:?}", constraint);
}
}
.potentially_quantified(self.tcx, ty::PredicateKind::ForAll);
Obligation::new(cause.clone(), param_env, predicate)
})
}
@ -666,10 +663,8 @@ impl<'tcx> TypeRelatingDelegate<'tcx> for QueryTypeRelatingDelegate<'_, 'tcx> {
self.obligations.push(Obligation {
cause: self.cause.clone(),
param_env: self.param_env,
predicate: ty::PredicateKind::RegionOutlives(ty::Binder::dummy(ty::OutlivesPredicate(
sup, sub,
)))
.to_predicate(self.infcx.tcx),
predicate: ty::PredicateAtom::RegionOutlives(ty::OutlivesPredicate(sup, sub))
.to_predicate(self.infcx.tcx),
recursion_depth: 0,
});
}

6
src/librustc_infer/infer/combine.rs
View file

@ -308,7 +308,7 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
self.obligations.push(Obligation::new(
self.trace.cause.clone(),
self.param_env,
ty::PredicateKind::WellFormed(b_ty.into()).to_predicate(self.infcx.tcx),
ty::PredicateAtom::WellFormed(b_ty.into()).to_predicate(self.infcx.tcx),
));
}
@ -400,9 +400,9 @@ impl<'infcx, 'tcx> CombineFields<'infcx, 'tcx> {
b: &'tcx ty::Const<'tcx>,
) {
let predicate = if a_is_expected {
ty::PredicateKind::ConstEquate(a, b)
ty::PredicateAtom::ConstEquate(a, b)
} else {
ty::PredicateKind::ConstEquate(b, a)
ty::PredicateAtom::ConstEquate(b, a)
};
self.obligations.push(Obligation::new(
self.trace.cause.clone(),

34
src/librustc_infer/infer/outlives/mod.rs
View file

@ -6,23 +6,29 @@ pub mod verify;
use rustc_middle::traits::query::OutlivesBound;
use rustc_middle::ty;
use rustc_middle::ty::fold::TypeFoldable;
pub fn explicit_outlives_bounds<'tcx>(
param_env: ty::ParamEnv<'tcx>,
) -> impl Iterator<Item = OutlivesBound<'tcx>> + 'tcx {
debug!("explicit_outlives_bounds()");
param_env.caller_bounds().into_iter().filter_map(move |predicate| match predicate.kind() {
ty::PredicateKind::Projection(..)
| ty::PredicateKind::Trait(..)
| ty::PredicateKind::Subtype(..)
| ty::PredicateKind::WellFormed(..)
| ty::PredicateKind::ObjectSafe(..)
| ty::PredicateKind::ClosureKind(..)
| ty::PredicateKind::TypeOutlives(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => None,
ty::PredicateKind::RegionOutlives(ref data) => data
.no_bound_vars()
.map(|ty::OutlivesPredicate(r_a, r_b)| OutlivesBound::RegionSubRegion(r_b, r_a)),
})
param_env
.caller_bounds()
.into_iter()
.map(ty::Predicate::skip_binders)
.filter(|atom| !atom.has_escaping_bound_vars())
.filter_map(move |atom| match atom {
ty::PredicateAtom::Projection(..)
| ty::PredicateAtom::Trait(..)
| ty::PredicateAtom::Subtype(..)
| ty::PredicateAtom::WellFormed(..)
| ty::PredicateAtom::ObjectSafe(..)
| ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::TypeOutlives(..)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => None,
ty::PredicateAtom::RegionOutlives(ty::OutlivesPredicate(r_a, r_b)) => {
Some(OutlivesBound::RegionSubRegion(r_b, r_a))
}
})
}

4
src/librustc_infer/infer/sub.rs
View file

@ -100,11 +100,11 @@ impl TypeRelation<'tcx> for Sub<'combine, 'infcx, 'tcx> {
self.fields.obligations.push(Obligation::new(
self.fields.trace.cause.clone(),
self.fields.param_env,
ty::PredicateKind::Subtype(ty::Binder::dummy(ty::SubtypePredicate {
ty::PredicateAtom::Subtype(ty::SubtypePredicate {
a_is_expected: self.a_is_expected,
a,
b,
}))
})
.to_predicate(self.tcx()),
));

88
src/librustc_infer/traits/util.rs
View file

@ -3,51 +3,20 @@ use smallvec::smallvec;
use crate::traits::{Obligation, ObligationCause, PredicateObligation};
use rustc_data_structures::fx::FxHashSet;
use rustc_middle::ty::outlives::Component;
use rustc_middle::ty::{self, ToPolyTraitRef, ToPredicate, TyCtxt, WithConstness};
use rustc_middle::ty::{self, ToPredicate, TyCtxt, WithConstness};
use rustc_span::Span;
pub fn anonymize_predicate<'tcx>(
tcx: TyCtxt<'tcx>,
pred: ty::Predicate<'tcx>,
) -> ty::Predicate<'tcx> {
let kind = pred.kind();
let new = match kind {
&ty::PredicateKind::Trait(ref data, constness) => {
ty::PredicateKind::Trait(tcx.anonymize_late_bound_regions(data), constness)
match pred.kind() {
ty::PredicateKind::ForAll(binder) => {
let new = ty::PredicateKind::ForAll(tcx.anonymize_late_bound_regions(binder));
tcx.reuse_or_mk_predicate(pred, new)
}
ty::PredicateKind::RegionOutlives(data) => {
ty::PredicateKind::RegionOutlives(tcx.anonymize_late_bound_regions(data))
}
ty::PredicateKind::TypeOutlives(data) => {
ty::PredicateKind::TypeOutlives(tcx.anonymize_late_bound_regions(data))
}
ty::PredicateKind::Projection(data) => {
ty::PredicateKind::Projection(tcx.anonymize_late_bound_regions(data))
}
&ty::PredicateKind::WellFormed(data) => ty::PredicateKind::WellFormed(data),
&ty::PredicateKind::ObjectSafe(data) => ty::PredicateKind::ObjectSafe(data),
&ty::PredicateKind::ClosureKind(closure_def_id, closure_substs, kind) => {
ty::PredicateKind::ClosureKind(closure_def_id, closure_substs, kind)
}
ty::PredicateKind::Subtype(data) => {
ty::PredicateKind::Subtype(tcx.anonymize_late_bound_regions(data))
}
&ty::PredicateKind::ConstEvaluatable(def_id, substs) => {
ty::PredicateKind::ConstEvaluatable(def_id, substs)
}
ty::PredicateKind::ConstEquate(c1, c2) => ty::PredicateKind::ConstEquate(c1, c2),
};
if new != *kind { new.to_predicate(tcx) } else { pred }
ty::PredicateKind::Atom(_) => pred,
}
}
struct PredicateSet<'tcx> {
@ -158,15 +127,16 @@ impl Elaborator<'tcx> {
fn elaborate(&mut self, obligation: &PredicateObligation<'tcx>) {
let tcx = self.visited.tcx;
match obligation.predicate.kind() {
ty::PredicateKind::Trait(ref data, _) => {
match obligation.predicate.skip_binders() {
ty::PredicateAtom::Trait(data, _) => {
// Get predicates declared on the trait.
let predicates = tcx.super_predicates_of(data.def_id());
let obligations = predicates.predicates.iter().map(|(pred, span)| {
let obligations = predicates.predicates.iter().map(|&(pred, span)| {
predicate_obligation(
pred.subst_supertrait(tcx, &data.to_poly_trait_ref()),
Some(*span),
pred.subst_supertrait(tcx, &ty::Binder::bind(data.trait_ref)),
Some(span),
)
});
debug!("super_predicates: data={:?}", data);
@ -180,36 +150,36 @@ impl Elaborator<'tcx> {
self.stack.extend(obligations);
}
ty::PredicateKind::WellFormed(..) => {
ty::PredicateAtom::WellFormed(..) => {
// Currently, we do not elaborate WF predicates,
// although we easily could.
}
ty::PredicateKind::ObjectSafe(..) => {
ty::PredicateAtom::ObjectSafe(..) => {
// Currently, we do not elaborate object-safe
// predicates.
}
ty::PredicateKind::Subtype(..) => {
ty::PredicateAtom::Subtype(..) => {
// Currently, we do not "elaborate" predicates like `X <: Y`,
// though conceivably we might.
}
ty::PredicateKind::Projection(..) => {
ty::PredicateAtom::Projection(..) => {
// Nothing to elaborate in a projection predicate.
}
ty::PredicateKind::ClosureKind(..) => {
ty::PredicateAtom::ClosureKind(..) => {
// Nothing to elaborate when waiting for a closure's kind to be inferred.
}
ty::PredicateKind::ConstEvaluatable(..) => {
ty::PredicateAtom::ConstEvaluatable(..) => {
// Currently, we do not elaborate const-evaluatable
// predicates.
}
ty::PredicateKind::ConstEquate(..) => {
ty::PredicateAtom::ConstEquate(..) => {
// Currently, we do not elaborate const-equate
// predicates.
}
ty::PredicateKind::RegionOutlives(..) => {
ty::PredicateAtom::RegionOutlives(..) => {
// Nothing to elaborate from `'a: 'b`.
}
ty::PredicateKind::TypeOutlives(ref data) => {
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(ty_max, r_min)) => {
// We know that `T: 'a` for some type `T`. We can
// often elaborate this. For example, if we know that
// `[U]: 'a`, that implies that `U: 'a`. Similarly, if
@ -224,8 +194,6 @@ impl Elaborator<'tcx> {
// consider this as evidence that `T: 'static`, but
// I'm a bit wary of such constructions and so for now
// I want to be conservative. --nmatsakis
let ty_max = data.skip_binder().0;
let r_min = data.skip_binder().1;
if r_min.is_late_bound() {
return;
}
@ -241,16 +209,16 @@ impl Elaborator<'tcx> {
if r.is_late_bound() {
None
} else {
Some(ty::PredicateKind::RegionOutlives(ty::Binder::dummy(
ty::OutlivesPredicate(r, r_min),
Some(ty::PredicateAtom::RegionOutlives(ty::OutlivesPredicate(
r, r_min,
)))
}
}
Component::Param(p) => {
let ty = tcx.mk_ty_param(p.index, p.name);
Some(ty::PredicateKind::TypeOutlives(ty::Binder::dummy(
ty::OutlivesPredicate(ty, r_min),
Some(ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(
ty, r_min,
)))
}
@ -331,8 +299,8 @@ impl<'tcx, I: Iterator<Item = PredicateObligation<'tcx>>> Iterator for FilterToT
fn next(&mut self) -> Option<ty::PolyTraitRef<'tcx>> {
while let Some(obligation) = self.base_iterator.next() {
if let ty::PredicateKind::Trait(data, _) = obligation.predicate.kind() {
return Some(data.to_poly_trait_ref());
if let Some(data) = obligation.predicate.to_opt_poly_trait_ref() {
return Some(data);
}
}
None

24
src/librustc_lint/builtin.rs
View file

@ -1202,13 +1202,13 @@ declare_lint_pass!(
impl<'tcx> LateLintPass<'tcx> for TrivialConstraints {
fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx hir::Item<'tcx>) {
use rustc_middle::ty::fold::TypeFoldable;
use rustc_middle::ty::PredicateKind::*;
use rustc_middle::ty::PredicateAtom::*;
if cx.tcx.features().trivial_bounds {
let def_id = cx.tcx.hir().local_def_id(item.hir_id);
let predicates = cx.tcx.predicates_of(def_id);
for &(predicate, span) in predicates.predicates {
let predicate_kind_name = match predicate.kind() {
let predicate_kind_name = match predicate.skip_binders() {
Trait(..) => "Trait",
TypeOutlives(..) |
RegionOutlives(..) => "Lifetime",
@ -1497,14 +1497,11 @@ impl ExplicitOutlivesRequirements {
) -> Vec<ty::Region<'tcx>> {
inferred_outlives
.iter()
.filter_map(|(pred, _)| match pred.kind() {
ty::PredicateKind::RegionOutlives(outlives) => {
let outlives = outlives.skip_binder();
match outlives.0 {
ty::ReEarlyBound(ebr) if ebr.index == index => Some(outlives.1),
_ => None,
}
}
.filter_map(|(pred, _)| match pred.skip_binders() {
ty::PredicateAtom::RegionOutlives(ty::OutlivesPredicate(a, b)) => match a {
ty::ReEarlyBound(ebr) if ebr.index == index => Some(b),
_ => None,
},
_ => None,
})
.collect()
@ -1516,10 +1513,9 @@ impl ExplicitOutlivesRequirements {
) -> Vec<ty::Region<'tcx>> {
inferred_outlives
.iter()
.filter_map(|(pred, _)| match pred.kind() {
ty::PredicateKind::TypeOutlives(outlives) => {
let outlives = outlives.skip_binder();
outlives.0.is_param(index).then_some(outlives.1)
.filter_map(|(pred, _)| match pred.skip_binders() {
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(a, b)) => {
a.is_param(index).then_some(b)
}
_ => None,
})

8
src/librustc_lint/unused.rs
View file

@ -146,11 +146,11 @@ impl<'tcx> LateLintPass<'tcx> for UnusedResults {
ty::Opaque(def, _) => {
let mut has_emitted = false;
for (predicate, _) in cx.tcx.predicates_of(def).predicates {
if let ty::PredicateKind::Trait(ref poly_trait_predicate, _) =
predicate.kind()
// We only look at the `DefId`, so it is safe to skip the binder here.
if let ty::PredicateAtom::Trait(ref poly_trait_predicate, _) =
predicate.skip_binders()
{
let trait_ref = poly_trait_predicate.skip_binder().trait_ref;
let def_id = trait_ref.def_id;
let def_id = poly_trait_predicate.trait_ref.def_id;
let descr_pre =
&format!("{}implementer{} of ", descr_pre, plural_suffix,);
if check_must_use_def(cx, def_id, span, descr_pre, descr_post) {

14
src/librustc_middle/ty/context.rs
View file

@ -102,7 +102,6 @@ impl<'tcx> CtxtInterners<'tcx> {
projs: Default::default(),
place_elems: Default::default(),
const_: Default::default(),
chalk_environment_clause_list: Default::default(),
}
}
@ -2128,16 +2127,25 @@ impl<'tcx> TyCtxt<'tcx> {
#[allow(rustc::usage_of_ty_tykind)]
#[inline]
pub fn mk_ty(&self, st: TyKind<'tcx>) -> Ty<'tcx> {
pub fn mk_ty(self, st: TyKind<'tcx>) -> Ty<'tcx> {
self.interners.intern_ty(st)
}
#[inline]
pub fn mk_predicate(&self, kind: PredicateKind<'tcx>) -> Predicate<'tcx> {
pub fn mk_predicate(self, kind: PredicateKind<'tcx>) -> Predicate<'tcx> {
let inner = self.interners.intern_predicate(kind);
Predicate { inner }
}
#[inline]
pub fn reuse_or_mk_predicate(
self,
pred: Predicate<'tcx>,
kind: PredicateKind<'tcx>,
) -> Predicate<'tcx> {
if *pred.kind() != kind { self.mk_predicate(kind) } else { pred }
}
pub fn mk_mach_int(self, tm: ast::IntTy) -> Ty<'tcx> {
match tm {
ast::IntTy::Isize => self.types.isize,

64
src/librustc_middle/ty/flags.rs
View file

@ -203,55 +203,49 @@ impl FlagComputation {
fn add_predicate_kind(&mut self, kind: &ty::PredicateKind<'_>) {
match kind {
ty::PredicateKind::Trait(trait_pred, _constness) => {
ty::PredicateKind::ForAll(binder) => {
let mut computation = FlagComputation::new();
computation.add_substs(trait_pred.skip_binder().trait_ref.substs);
computation.add_predicate_atom(binder.skip_binder());
self.add_bound_computation(computation);
}
ty::PredicateKind::RegionOutlives(poly_outlives) => {
let mut computation = FlagComputation::new();
let ty::OutlivesPredicate(a, b) = poly_outlives.skip_binder();
computation.add_region(a);
computation.add_region(b);
&ty::PredicateKind::Atom(atom) => self.add_predicate_atom(atom),
}
}
self.add_bound_computation(computation);
fn add_predicate_atom(&mut self, atom: ty::PredicateAtom<'_>) {
match atom {
ty::PredicateAtom::Trait(trait_pred, _constness) => {
self.add_substs(trait_pred.trait_ref.substs);
}
ty::PredicateKind::TypeOutlives(poly_outlives) => {
let mut computation = FlagComputation::new();
let ty::OutlivesPredicate(ty, region) = poly_outlives.skip_binder();
computation.add_ty(ty);
computation.add_region(region);
self.add_bound_computation(computation);
ty::PredicateAtom::RegionOutlives(ty::OutlivesPredicate(a, b)) => {
self.add_region(a);
self.add_region(b);
}
ty::PredicateKind::Subtype(poly_subtype) => {
let mut computation = FlagComputation::new();
let ty::SubtypePredicate { a_is_expected: _, a, b } = poly_subtype.skip_binder();
computation.add_ty(a);
computation.add_ty(b);
self.add_bound_computation(computation);
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(ty, region)) => {
self.add_ty(ty);
self.add_region(region);
}
&ty::PredicateKind::Projection(projection) => {
let mut computation = FlagComputation::new();
let ty::ProjectionPredicate { projection_ty, ty } = projection.skip_binder();
computation.add_projection_ty(projection_ty);
computation.add_ty(ty);
self.add_bound_computation(computation);
ty::PredicateAtom::Subtype(ty::SubtypePredicate { a_is_expected: _, a, b }) => {
self.add_ty(a);
self.add_ty(b);
}
ty::PredicateKind::WellFormed(arg) => {
self.add_substs(slice::from_ref(arg));
ty::PredicateAtom::Projection(ty::ProjectionPredicate { projection_ty, ty }) => {
self.add_projection_ty(projection_ty);
self.add_ty(ty);
}
ty::PredicateKind::ObjectSafe(_def_id) => {}
ty::PredicateKind::ClosureKind(_def_id, substs, _kind) => {
ty::PredicateAtom::WellFormed(arg) => {
self.add_substs(slice::from_ref(&arg));
}
ty::PredicateAtom::ObjectSafe(_def_id) => {}
ty::PredicateAtom::ClosureKind(_def_id, substs, _kind) => {
self.add_substs(substs);
}
ty::PredicateKind::ConstEvaluatable(_def_id, substs) => {
ty::PredicateAtom::ConstEvaluatable(_def_id, substs) => {
self.add_substs(substs);
}
ty::PredicateKind::ConstEquate(expected, found) => {
ty::PredicateAtom::ConstEquate(expected, found) => {
self.add_const(expected);
self.add_const(found);
}

208
src/librustc_middle/ty/mod.rs
View file

@ -1018,7 +1018,7 @@ crate struct PredicateInner<'tcx> {
}
#[cfg(target_arch = "x86_64")]
static_assert_size!(PredicateInner<'_>, 40);
static_assert_size!(PredicateInner<'_>, 48);
#[derive(Clone, Copy, Lift)]
pub struct Predicate<'tcx> {
@ -1048,6 +1048,44 @@ impl<'tcx> Predicate<'tcx> {
pub fn kind(self) -> &'tcx PredicateKind<'tcx> {
&self.inner.kind
}
/// Returns the inner `PredicateAtom`.
///
/// The returned atom may contain unbound variables bound to binders skipped in this method.
/// It is safe to reapply binders to the given atom.
///
/// Note that this method panics in case this predicate has unbound variables.
pub fn skip_binders(self) -> PredicateAtom<'tcx> {
match self.kind() {
&PredicateKind::ForAll(binder) => binder.skip_binder(),
&PredicateKind::Atom(atom) => {
debug_assert!(!atom.has_escaping_bound_vars());
atom
}
}
}
/// Returns the inner `PredicateAtom`.
///
/// Note that this method does not check if the predicate has unbound variables.
///
/// Rebinding the returned atom can causes the previously bound variables
/// to end up at the wrong binding level.
pub fn skip_binders_unchecked(self) -> PredicateAtom<'tcx> {
match self.kind() {
&PredicateKind::ForAll(binder) => binder.skip_binder(),
&PredicateKind::Atom(atom) => atom,
}
}
/// Allows using a `Binder<PredicateAtom<'tcx>>` even if the given predicate previously
/// contained unbound variables by shifting these variables outwards.
pub fn bound_atom(self, tcx: TyCtxt<'tcx>) -> Binder<PredicateAtom<'tcx>> {
match self.kind() {
&PredicateKind::ForAll(binder) => binder,
&PredicateKind::Atom(atom) => Binder::wrap_nonbinding(tcx, atom),
}
}
}
impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for Predicate<'tcx> {
@ -1068,6 +1106,14 @@ impl<'a, 'tcx> HashStable<StableHashingContext<'a>> for Predicate<'tcx> {
#[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
#[derive(HashStable, TypeFoldable)]
pub enum PredicateKind<'tcx> {
/// `for<'a>: ...`
ForAll(Binder<PredicateAtom<'tcx>>),
Atom(PredicateAtom<'tcx>),
}
#[derive(Clone, Copy, PartialEq, Eq, Hash, RustcEncodable, RustcDecodable)]
#[derive(HashStable, TypeFoldable)]
pub enum PredicateAtom<'tcx> {
/// Corresponds to `where Foo: Bar<A, B, C>`. `Foo` here would be
/// the `Self` type of the trait reference and `A`, `B`, and `C`
/// would be the type parameters.
@ -1075,17 +1121,17 @@ pub enum PredicateKind<'tcx> {
/// A trait predicate will have `Constness::Const` if it originates
/// from a bound on a `const fn` without the `?const` opt-out (e.g.,
/// `const fn foobar<Foo: Bar>() {}`).
Trait(PolyTraitPredicate<'tcx>, Constness),
Trait(TraitPredicate<'tcx>, Constness),
/// `where 'a: 'b`
RegionOutlives(PolyRegionOutlivesPredicate<'tcx>),
RegionOutlives(RegionOutlivesPredicate<'tcx>),
/// `where T: 'a`
TypeOutlives(PolyTypeOutlivesPredicate<'tcx>),
TypeOutlives(TypeOutlivesPredicate<'tcx>),
/// `where <T as TraitRef>::Name == X`, approximately.
/// See the `ProjectionPredicate` struct for details.
Projection(PolyProjectionPredicate<'tcx>),
Projection(ProjectionPredicate<'tcx>),
/// No syntax: `T` well-formed.
WellFormed(GenericArg<'tcx>),
@ -1099,7 +1145,7 @@ pub enum PredicateKind<'tcx> {
ClosureKind(DefId, SubstsRef<'tcx>, ClosureKind),
/// `T1 <: T2`
Subtype(PolySubtypePredicate<'tcx>),
Subtype(SubtypePredicate<'tcx>),
/// Constant initializer must evaluate successfully.
ConstEvaluatable(ty::WithOptConstParam<DefId>, SubstsRef<'tcx>),
@ -1108,6 +1154,22 @@ pub enum PredicateKind<'tcx> {
ConstEquate(&'tcx Const<'tcx>, &'tcx Const<'tcx>),
}
impl<'tcx> PredicateAtom<'tcx> {
/// Wraps `self` with the given qualifier if this predicate has any unbound variables.
pub fn potentially_quantified(
self,
tcx: TyCtxt<'tcx>,
qualifier: impl FnOnce(Binder<PredicateAtom<'tcx>>) -> PredicateKind<'tcx>,
) -> Predicate<'tcx> {
if self.has_escaping_bound_vars() {
qualifier(Binder::bind(self))
} else {
PredicateKind::Atom(self)
}
.to_predicate(tcx)
}
}
/// The crate outlives map is computed during typeck and contains the
/// outlives of every item in the local crate. You should not use it
/// directly, because to do so will make your pass dependent on the
@ -1119,7 +1181,7 @@ pub struct CratePredicatesMap<'tcx> {
/// For each struct with outlive bounds, maps to a vector of the
/// predicate of its outlive bounds. If an item has no outlives
/// bounds, it will have no entry.
pub predicates: FxHashMap<DefId, &'tcx [(ty::Predicate<'tcx>, Span)]>,
pub predicates: FxHashMap<DefId, &'tcx [(Predicate<'tcx>, Span)]>,
}
impl<'tcx> Predicate<'tcx> {
@ -1132,7 +1194,7 @@ impl<'tcx> Predicate<'tcx> {
self,
tcx: TyCtxt<'tcx>,
trait_ref: &ty::PolyTraitRef<'tcx>,
) -> ty::Predicate<'tcx> {
) -> Predicate<'tcx> {
// The interaction between HRTB and supertraits is not entirely
// obvious. Let me walk you (and myself) through an example.
//
@ -1192,39 +1254,10 @@ impl<'tcx> Predicate<'tcx> {
// substitution code expects equal binding levels in the values
// from the substitution and the value being substituted into, and
// this trick achieves that).
let substs = &trait_ref.skip_binder().substs;
let kind = self.kind();
let new = match kind {
&PredicateKind::Trait(ref binder, constness) => {
PredicateKind::Trait(binder.map_bound(|data| data.subst(tcx, substs)), constness)
}
PredicateKind::Subtype(binder) => {
PredicateKind::Subtype(binder.map_bound(|data| data.subst(tcx, substs)))
}
PredicateKind::RegionOutlives(binder) => {
PredicateKind::RegionOutlives(binder.map_bound(|data| data.subst(tcx, substs)))
}
PredicateKind::TypeOutlives(binder) => {
PredicateKind::TypeOutlives(binder.map_bound(|data| data.subst(tcx, substs)))
}
PredicateKind::Projection(binder) => {
PredicateKind::Projection(binder.map_bound(|data| data.subst(tcx, substs)))
}
&PredicateKind::WellFormed(data) => PredicateKind::WellFormed(data.subst(tcx, substs)),
&PredicateKind::ObjectSafe(trait_def_id) => PredicateKind::ObjectSafe(trait_def_id),
&PredicateKind::ClosureKind(closure_def_id, closure_substs, kind) => {
PredicateKind::ClosureKind(closure_def_id, closure_substs.subst(tcx, substs), kind)
}
&PredicateKind::ConstEvaluatable(def_id, const_substs) => {
PredicateKind::ConstEvaluatable(def_id, const_substs.subst(tcx, substs))
}
PredicateKind::ConstEquate(c1, c2) => {
PredicateKind::ConstEquate(c1.subst(tcx, substs), c2.subst(tcx, substs))
}
};
if new != *kind { new.to_predicate(tcx) } else { self }
let substs = trait_ref.skip_binder().substs;
let pred = self.skip_binders();
let new = pred.subst(tcx, substs);
if new != pred { new.potentially_quantified(tcx, PredicateKind::ForAll) } else { self }
}
}
@ -1349,86 +1382,87 @@ impl ToPredicate<'tcx> for PredicateKind<'tcx> {
}
}
impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<TraitRef<'tcx>> {
impl ToPredicate<'tcx> for PredicateAtom<'tcx> {
#[inline(always)]
fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
ty::PredicateKind::Trait(
ty::Binder::dummy(ty::TraitPredicate { trait_ref: self.value }),
self.constness,
)
.to_predicate(tcx)
debug_assert!(!self.has_escaping_bound_vars(), "escaping bound vars for {:?}", self);
tcx.mk_predicate(PredicateKind::Atom(self))
}
}
impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<&TraitRef<'tcx>> {
impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<TraitRef<'tcx>> {
fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
ty::PredicateKind::Trait(
ty::Binder::dummy(ty::TraitPredicate { trait_ref: *self.value }),
self.constness,
)
.to_predicate(tcx)
PredicateAtom::Trait(ty::TraitPredicate { trait_ref: self.value }, self.constness)
.to_predicate(tcx)
}
}
impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<PolyTraitRef<'tcx>> {
fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
ty::PredicateKind::Trait(self.value.to_poly_trait_predicate(), self.constness)
.to_predicate(tcx)
ConstnessAnd {
value: self.value.map_bound(|trait_ref| ty::TraitPredicate { trait_ref }),
constness: self.constness,
}
.to_predicate(tcx)
}
}
impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<&PolyTraitRef<'tcx>> {
impl<'tcx> ToPredicate<'tcx> for ConstnessAnd<PolyTraitPredicate<'tcx>> {
fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
ty::PredicateKind::Trait(self.value.to_poly_trait_predicate(), self.constness)
.to_predicate(tcx)
PredicateAtom::Trait(self.value.skip_binder(), self.constness)
.potentially_quantified(tcx, PredicateKind::ForAll)
}
}
impl<'tcx> ToPredicate<'tcx> for PolyRegionOutlivesPredicate<'tcx> {
fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
PredicateKind::RegionOutlives(self).to_predicate(tcx)
PredicateAtom::RegionOutlives(self.skip_binder())
.potentially_quantified(tcx, PredicateKind::ForAll)
}
}
impl<'tcx> ToPredicate<'tcx> for PolyTypeOutlivesPredicate<'tcx> {
fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
PredicateKind::TypeOutlives(self).to_predicate(tcx)
PredicateAtom::TypeOutlives(self.skip_binder())
.potentially_quantified(tcx, PredicateKind::ForAll)
}
}
impl<'tcx> ToPredicate<'tcx> for PolyProjectionPredicate<'tcx> {
fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
PredicateKind::Projection(self).to_predicate(tcx)
PredicateAtom::Projection(self.skip_binder())
.potentially_quantified(tcx, PredicateKind::ForAll)
}
}
impl<'tcx> Predicate<'tcx> {
pub fn to_opt_poly_trait_ref(self) -> Option<PolyTraitRef<'tcx>> {
match self.kind() {
&PredicateKind::Trait(ref t, _) => Some(t.to_poly_trait_ref()),
PredicateKind::Projection(..)
| PredicateKind::Subtype(..)
| PredicateKind::RegionOutlives(..)
| PredicateKind::WellFormed(..)
| PredicateKind::ObjectSafe(..)
| PredicateKind::ClosureKind(..)
| PredicateKind::TypeOutlives(..)
| PredicateKind::ConstEvaluatable(..)
| PredicateKind::ConstEquate(..) => None,
match self.skip_binders() {
PredicateAtom::Trait(t, _) => Some(ty::Binder::bind(t.trait_ref)),
PredicateAtom::Projection(..)
| PredicateAtom::Subtype(..)
| PredicateAtom::RegionOutlives(..)
| PredicateAtom::WellFormed(..)
| PredicateAtom::ObjectSafe(..)
| PredicateAtom::ClosureKind(..)
| PredicateAtom::TypeOutlives(..)
| PredicateAtom::ConstEvaluatable(..)
| PredicateAtom::ConstEquate(..) => None,
}
}
pub fn to_opt_type_outlives(self) -> Option<PolyTypeOutlivesPredicate<'tcx>> {
match self.kind() {
&PredicateKind::TypeOutlives(data) => Some(data),
PredicateKind::Trait(..)
| PredicateKind::Projection(..)
| PredicateKind::Subtype(..)
| PredicateKind::RegionOutlives(..)
| PredicateKind::WellFormed(..)
| PredicateKind::ObjectSafe(..)
| PredicateKind::ClosureKind(..)
| PredicateKind::ConstEvaluatable(..)
| PredicateKind::ConstEquate(..) => None,
match self.skip_binders() {
PredicateAtom::TypeOutlives(data) => Some(ty::Binder::bind(data)),
PredicateAtom::Trait(..)
| PredicateAtom::Projection(..)
| PredicateAtom::Subtype(..)
| PredicateAtom::RegionOutlives(..)
| PredicateAtom::WellFormed(..)
| PredicateAtom::ObjectSafe(..)
| PredicateAtom::ClosureKind(..)
| PredicateAtom::ConstEvaluatable(..)
| PredicateAtom::ConstEquate(..) => None,
}
}
}
@ -1692,7 +1726,7 @@ pub struct ParamEnv<'tcx> {
// Specifically, the low bit represents Reveal, with 0 meaning `UserFacing`
// and 1 meaning `All`. The rest is the pointer.
//
// This relies on the List<ty::Predicate<'tcx>> type having at least 2-byte
// This relies on the List<Predicate<'tcx>> type having at least 2-byte
// alignment. Lists start with a usize and are repr(C) so this should be
// fine; there is a debug_assert in the constructor as well.
//
@ -1706,7 +1740,7 @@ pub struct ParamEnv<'tcx> {
///
/// Note: This is packed into the `packed_data` usize above, use the
/// `caller_bounds()` method to access it.
caller_bounds: PhantomData<&'tcx List<ty::Predicate<'tcx>>>,
caller_bounds: PhantomData<&'tcx List<Predicate<'tcx>>>,
/// Typically, this is `Reveal::UserFacing`, but during codegen we
/// want `Reveal::All`.
@ -1784,7 +1818,7 @@ impl<'tcx> ParamEnv<'tcx> {
}
#[inline]
pub fn caller_bounds(self) -> &'tcx List<ty::Predicate<'tcx>> {
pub fn caller_bounds(self) -> &'tcx List<Predicate<'tcx>> {
// mask out bottom bit
unsafe { &*((self.packed_data & (!1)) as *const _) }
}
@ -1809,7 +1843,7 @@ impl<'tcx> ParamEnv<'tcx> {
/// Construct a trait environment with the given set of predicates.
#[inline]
pub fn new(
caller_bounds: &'tcx List<ty::Predicate<'tcx>>,
caller_bounds: &'tcx List<Predicate<'tcx>>,
reveal: Reveal,
def_id: Option<DefId>,
) -> Self {

56
src/librustc_middle/ty/print/pretty.rs
View file

@ -572,7 +572,14 @@ pub trait PrettyPrinter<'tcx>:
let mut is_sized = false;
p!(write("impl"));
for predicate in bounds.predicates {
if let Some(trait_ref) = predicate.to_opt_poly_trait_ref() {
// Note: We can't use `to_opt_poly_trait_ref` here as `predicate`
// may contain unbound variables. We therefore do this manually.
//
// FIXME(lcnr): Find out why exactly this is the case :)
if let ty::PredicateAtom::Trait(pred, _) =
predicate.bound_atom(self.tcx()).skip_binder()
{
let trait_ref = ty::Binder::bind(pred.trait_ref);
// Don't print +Sized, but rather +?Sized if absent.
if Some(trait_ref.def_id()) == self.tcx().lang_items().sized_trait() {
is_sized = true;
@ -2006,38 +2013,45 @@ define_print_and_forward_display! {
ty::Predicate<'tcx> {
match self.kind() {
&ty::PredicateKind::Trait(ref data, constness) => {
&ty::PredicateKind::Atom(atom) => p!(print(atom)),
ty::PredicateKind::ForAll(binder) => p!(print(binder)),
}
}
ty::PredicateAtom<'tcx> {
match *self {
ty::PredicateAtom::Trait(ref data, constness) => {
if let hir::Constness::Const = constness {
p!(write("const "));
}
p!(print(data))
}
ty::PredicateKind::Subtype(predicate) => p!(print(predicate)),
ty::PredicateKind::RegionOutlives(predicate) => p!(print(predicate)),
ty::PredicateKind::TypeOutlives(predicate) => p!(print(predicate)),
ty::PredicateKind::Projection(predicate) => p!(print(predicate)),
ty::PredicateKind::WellFormed(arg) => p!(print(arg), write(" well-formed")),
&ty::PredicateKind::ObjectSafe(trait_def_id) => {
ty::PredicateAtom::Subtype(predicate) => p!(print(predicate)),
ty::PredicateAtom::RegionOutlives(predicate) => p!(print(predicate)),
ty::PredicateAtom::TypeOutlives(predicate) => p!(print(predicate)),
ty::PredicateAtom::Projection(predicate) => p!(print(predicate)),
ty::PredicateAtom::WellFormed(arg) => p!(print(arg), write(" well-formed")),
ty::PredicateAtom::ObjectSafe(trait_def_id) => {
p!(write("the trait `"),
print_def_path(trait_def_id, &[]),
write("` is object-safe"))
print_def_path(trait_def_id, &[]),
write("` is object-safe"))
}
&ty::PredicateKind::ClosureKind(closure_def_id, _closure_substs, kind) => {
ty::PredicateAtom::ClosureKind(closure_def_id, _closure_substs, kind) => {
p!(write("the closure `"),
print_value_path(closure_def_id, &[]),
write("` implements the trait `{}`", kind))
print_value_path(closure_def_id, &[]),
write("` implements the trait `{}`", kind))
}
&ty::PredicateKind::ConstEvaluatable(def, substs) => {
ty::PredicateAtom::ConstEvaluatable(def, substs) => {
p!(write("the constant `"),
print_value_path(def.did, substs),
write("` can be evaluated"))
print_value_path(def.did, substs),
write("` can be evaluated"))
}
ty::PredicateKind::ConstEquate(c1, c2) => {
ty::PredicateAtom::ConstEquate(c1, c2) => {
p!(write("the constant `"),
print(c1),
write("` equals `"),
print(c2),
write("`"))
print(c1),
write("` equals `"),
print(c2),
write("`"))
}
}
}

79
src/librustc_middle/ty/structural_impls.rs
View file

@ -226,27 +226,36 @@ impl fmt::Debug for ty::Predicate<'tcx> {
impl fmt::Debug for ty::PredicateKind<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
ty::PredicateKind::Trait(ref a, constness) => {
ty::PredicateKind::ForAll(binder) => write!(f, "ForAll({:?})", binder),
ty::PredicateKind::Atom(atom) => write!(f, "{:?}", atom),
}
}
}
impl fmt::Debug for ty::PredicateAtom<'tcx> {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match *self {
ty::PredicateAtom::Trait(ref a, constness) => {
if let hir::Constness::Const = constness {
write!(f, "const ")?;
}
a.fmt(f)
}
ty::PredicateKind::Subtype(ref pair) => pair.fmt(f),
ty::PredicateKind::RegionOutlives(ref pair) => pair.fmt(f),
ty::PredicateKind::TypeOutlives(ref pair) => pair.fmt(f),
ty::PredicateKind::Projection(ref pair) => pair.fmt(f),
ty::PredicateKind::WellFormed(data) => write!(f, "WellFormed({:?})", data),
ty::PredicateKind::ObjectSafe(trait_def_id) => {
ty::PredicateAtom::Subtype(ref pair) => pair.fmt(f),
ty::PredicateAtom::RegionOutlives(ref pair) => pair.fmt(f),
ty::PredicateAtom::TypeOutlives(ref pair) => pair.fmt(f),
ty::PredicateAtom::Projection(ref pair) => pair.fmt(f),
ty::PredicateAtom::WellFormed(data) => write!(f, "WellFormed({:?})", data),
ty::PredicateAtom::ObjectSafe(trait_def_id) => {
write!(f, "ObjectSafe({:?})", trait_def_id)
}
ty::PredicateKind::ClosureKind(closure_def_id, closure_substs, kind) => {
ty::PredicateAtom::ClosureKind(closure_def_id, closure_substs, kind) => {
write!(f, "ClosureKind({:?}, {:?}, {:?})", closure_def_id, closure_substs, kind)
}
ty::PredicateKind::ConstEvaluatable(def_id, substs) => {
ty::PredicateAtom::ConstEvaluatable(def_id, substs) => {
write!(f, "ConstEvaluatable({:?}, {:?})", def_id, substs)
}
ty::PredicateKind::ConstEquate(c1, c2) => write!(f, "ConstEquate({:?}, {:?})", c1, c2),
ty::PredicateAtom::ConstEquate(c1, c2) => write!(f, "ConstEquate({:?}, {:?})", c1, c2),
}
}
}
@ -476,37 +485,45 @@ impl<'a, 'tcx> Lift<'tcx> for ty::ExistentialProjection<'a> {
impl<'a, 'tcx> Lift<'tcx> for ty::PredicateKind<'a> {
type Lifted = ty::PredicateKind<'tcx>;
fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
match self {
ty::PredicateKind::ForAll(binder) => tcx.lift(binder).map(ty::PredicateKind::ForAll),
ty::PredicateKind::Atom(atom) => tcx.lift(atom).map(ty::PredicateKind::Atom),
}
}
}
impl<'a, 'tcx> Lift<'tcx> for ty::PredicateAtom<'a> {
type Lifted = ty::PredicateAtom<'tcx>;
fn lift_to_tcx(&self, tcx: TyCtxt<'tcx>) -> Option<Self::Lifted> {
match *self {
ty::PredicateKind::Trait(ref binder, constness) => {
tcx.lift(binder).map(|binder| ty::PredicateKind::Trait(binder, constness))
ty::PredicateAtom::Trait(ref data, constness) => {
tcx.lift(data).map(|data| ty::PredicateAtom::Trait(data, constness))
}
ty::PredicateKind::Subtype(ref binder) => {
tcx.lift(binder).map(ty::PredicateKind::Subtype)
ty::PredicateAtom::Subtype(ref data) => tcx.lift(data).map(ty::PredicateAtom::Subtype),
ty::PredicateAtom::RegionOutlives(ref data) => {
tcx.lift(data).map(ty::PredicateAtom::RegionOutlives)
}
ty::PredicateKind::RegionOutlives(ref binder) => {
tcx.lift(binder).map(ty::PredicateKind::RegionOutlives)
ty::PredicateAtom::TypeOutlives(ref data) => {
tcx.lift(data).map(ty::PredicateAtom::TypeOutlives)
}
ty::PredicateKind::TypeOutlives(ref binder) => {
tcx.lift(binder).map(ty::PredicateKind::TypeOutlives)
ty::PredicateAtom::Projection(ref data) => {
tcx.lift(data).map(ty::PredicateAtom::Projection)
}
ty::PredicateKind::Projection(ref binder) => {
tcx.lift(binder).map(ty::PredicateKind::Projection)
}
ty::PredicateKind::WellFormed(ty) => tcx.lift(&ty).map(ty::PredicateKind::WellFormed),
ty::PredicateKind::ClosureKind(closure_def_id, closure_substs, kind) => {
ty::PredicateAtom::WellFormed(ty) => tcx.lift(&ty).map(ty::PredicateAtom::WellFormed),
ty::PredicateAtom::ClosureKind(closure_def_id, closure_substs, kind) => {
tcx.lift(&closure_substs).map(|closure_substs| {
ty::PredicateKind::ClosureKind(closure_def_id, closure_substs, kind)
ty::PredicateAtom::ClosureKind(closure_def_id, closure_substs, kind)
})
}
ty::PredicateKind::ObjectSafe(trait_def_id) => {
Some(ty::PredicateKind::ObjectSafe(trait_def_id))
ty::PredicateAtom::ObjectSafe(trait_def_id) => {
Some(ty::PredicateAtom::ObjectSafe(trait_def_id))
}
ty::PredicateKind::ConstEvaluatable(def_id, substs) => {
tcx.lift(&substs).map(|substs| ty::PredicateKind::ConstEvaluatable(def_id, substs))
ty::PredicateAtom::ConstEvaluatable(def_id, substs) => {
tcx.lift(&substs).map(|substs| ty::PredicateAtom::ConstEvaluatable(def_id, substs))
}
ty::PredicateKind::ConstEquate(c1, c2) => {
tcx.lift(&(c1, c2)).map(|(c1, c2)| ty::PredicateKind::ConstEquate(c1, c2))
ty::PredicateAtom::ConstEquate(c1, c2) => {
tcx.lift(&(c1, c2)).map(|(c1, c2)| ty::PredicateAtom::ConstEquate(c1, c2))
}
}
}
@ -998,7 +1015,7 @@ impl<'tcx> TypeFoldable<'tcx> for ty::Region<'tcx> {
impl<'tcx> TypeFoldable<'tcx> for ty::Predicate<'tcx> {
fn super_fold_with<F: TypeFolder<'tcx>>(&self, folder: &mut F) -> Self {
let new = ty::PredicateKind::super_fold_with(&self.inner.kind, folder);
if new != self.inner.kind { folder.tcx().mk_predicate(new) } else { *self }
folder.tcx().reuse_or_mk_predicate(*self, new)
}
fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {

28
src/librustc_middle/ty/sty.rs
View file

@ -652,8 +652,7 @@ impl<'tcx> Binder<ExistentialPredicate<'tcx>> {
Binder(tr).with_self_ty(tcx, self_ty).without_const().to_predicate(tcx)
}
ExistentialPredicate::Projection(p) => {
ty::PredicateKind::Projection(Binder(p.with_self_ty(tcx, self_ty)))
.to_predicate(tcx)
Binder(p.with_self_ty(tcx, self_ty)).to_predicate(tcx)
}
ExistentialPredicate::AutoTrait(did) => {
let trait_ref =
@ -896,6 +895,22 @@ impl<T> Binder<T> {
Binder(value)
}
/// Wraps `value` in a binder without actually binding any currently
/// unbound variables.
///
/// Note that this will shift all debrujin indices of escaping bound variables
/// by 1 to avoid accidential captures.
pub fn wrap_nonbinding(tcx: TyCtxt<'tcx>, value: T) -> Binder<T>
where
T: TypeFoldable<'tcx>,
{
if value.has_escaping_bound_vars() {
Binder::bind(super::fold::shift_vars(tcx, &value, 1))
} else {
Binder::dummy(value)
}
}
/// Skips the binder and returns the "bound" value. This is a
/// risky thing to do because it's easy to get confused about
/// De Bruijn indices and the like. It is usually better to
@ -980,6 +995,15 @@ impl<T> Binder<T> {
}
}
impl<T> Binder<Option<T>> {
pub fn transpose(self) -> Option<Binder<T>> {
match self.0 {
Some(v) => Some(Binder(v)),
None => None,
}
}
}
/// Represents the projection of an associated type. In explicit UFCS
/// form this would be written `<T as Trait<..>>::N`.
#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, RustcEncodable, RustcDecodable)]

8
src/librustc_mir/borrow_check/diagnostics/region_errors.rs
View file

@ -589,10 +589,10 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
let mut found = false;
for predicate in bounds.predicates {
if let ty::PredicateKind::TypeOutlives(binder) = predicate.kind() {
if let ty::OutlivesPredicate(_, ty::RegionKind::ReStatic) =
binder.skip_binder()
{
if let ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(_, r)) =
predicate.skip_binders()
{
if let ty::RegionKind::ReStatic = r {
found = true;
break;
} else {

34
src/librustc_mir/borrow_check/type_check/mod.rs
View file

@ -27,8 +27,8 @@ use rustc_middle::ty::cast::CastTy;
use rustc_middle::ty::fold::TypeFoldable;
use rustc_middle::ty::subst::{GenericArgKind, Subst, SubstsRef, UserSubsts};
use rustc_middle::ty::{
self, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, RegionVid, ToPolyTraitRef,
ToPredicate, Ty, TyCtxt, UserType, UserTypeAnnotationIndex,
self, CanonicalUserTypeAnnotation, CanonicalUserTypeAnnotations, RegionVid, ToPredicate, Ty,
TyCtxt, UserType, UserTypeAnnotationIndex, WithConstness,
};
use rustc_span::{Span, DUMMY_SP};
use rustc_target::abi::VariantIdx;
@ -1021,7 +1021,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
}
self.prove_predicate(
ty::PredicateKind::WellFormed(inferred_ty.into()).to_predicate(self.tcx()),
ty::PredicateAtom::WellFormed(inferred_ty.into()).to_predicate(self.tcx()),
Locations::All(span),
ConstraintCategory::TypeAnnotation,
);
@ -1273,7 +1273,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
obligations.obligations.push(traits::Obligation::new(
ObligationCause::dummy(),
param_env,
ty::PredicateKind::WellFormed(revealed_ty.into()).to_predicate(infcx.tcx),
ty::PredicateAtom::WellFormed(revealed_ty.into()).to_predicate(infcx.tcx),
));
obligations.add(
infcx
@ -1617,7 +1617,7 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
self.check_call_dest(body, term, &sig, destination, term_location);
self.prove_predicates(
sig.inputs_and_output.iter().map(|ty| ty::PredicateKind::WellFormed(ty.into())),
sig.inputs_and_output.iter().map(|ty| ty::PredicateAtom::WellFormed(ty.into())),
term_location.to_locations(),
ConstraintCategory::Boring,
);
@ -2022,18 +2022,14 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
traits::ObligationCauseCode::RepeatVec(should_suggest),
),
self.param_env,
ty::PredicateKind::Trait(
ty::Binder::bind(ty::TraitPredicate {
trait_ref: ty::TraitRef::new(
self.tcx().require_lang_item(
CopyTraitLangItem,
Some(self.last_span),
),
tcx.mk_substs_trait(ty, &[]),
),
}),
hir::Constness::NotConst,
)
ty::Binder::bind(ty::TraitRef::new(
self.tcx().require_lang_item(
CopyTraitLangItem,
Some(self.last_span),
),
tcx.mk_substs_trait(ty, &[]),
))
.without_const()
.to_predicate(self.tcx()),
),
&traits::SelectionError::Unimplemented,
@ -2706,8 +2702,8 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> {
category: ConstraintCategory,
) {
self.prove_predicates(
Some(ty::PredicateKind::Trait(
trait_ref.to_poly_trait_ref().to_poly_trait_predicate(),
Some(ty::PredicateAtom::Trait(
ty::TraitPredicate { trait_ref },
hir::Constness::NotConst,
)),
locations,

15
src/librustc_mir/monomorphize/polymorphize.rs
View file

@ -131,9 +131,9 @@ fn mark_used_by_predicates<'tcx>(
let predicates = tcx.explicit_predicates_of(def_id);
debug!("mark_parameters_used_in_predicates: predicates_of={:?}", predicates);
for (predicate, _) in predicates.predicates {
match predicate.kind() {
ty::PredicateKind::Trait(predicate, ..) => {
let trait_ref = predicate.skip_binder().trait_ref;
match predicate.skip_binders() {
ty::PredicateAtom::Trait(predicate, ..) => {
let trait_ref = predicate.trait_ref;
if is_self_ty_used(unused_parameters, trait_ref.self_ty()) {
for ty in trait_ref.substs.types() {
debug!("unused_generic_params: (trait) ty={:?}", ty);
@ -141,12 +141,11 @@ fn mark_used_by_predicates<'tcx>(
}
}
}
ty::PredicateKind::Projection(predicate, ..) => {
let self_ty = predicate.skip_binder().projection_ty.self_ty();
ty::PredicateAtom::Projection(proj, ..) => {
let self_ty = proj.projection_ty.self_ty();
if is_self_ty_used(unused_parameters, self_ty) {
let ty = predicate.ty();
debug!("unused_generic_params: (projection) ty={:?}", ty);
mark_ty(unused_parameters, ty.skip_binder());
debug!("unused_generic_params: (projection ty={:?}", proj.ty);
mark_ty(unused_parameters, proj.ty);
}
}
_ => (),

24
src/librustc_mir/transform/qualify_min_const_fn.rs
View file

@ -24,27 +24,27 @@ pub fn is_min_const_fn(tcx: TyCtxt<'tcx>, def_id: DefId, body: &'a Body<'tcx>) -
loop {
let predicates = tcx.predicates_of(current);
for (predicate, _) in predicates.predicates {
match predicate.kind() {
ty::PredicateKind::RegionOutlives(_)
| ty::PredicateKind::TypeOutlives(_)
| ty::PredicateKind::WellFormed(_)
| ty::PredicateKind::Projection(_)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => continue,
ty::PredicateKind::ObjectSafe(_) => {
match predicate.skip_binders() {
ty::PredicateAtom::RegionOutlives(_)
| ty::PredicateAtom::TypeOutlives(_)
| ty::PredicateAtom::WellFormed(_)
| ty::PredicateAtom::Projection(_)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => continue,
ty::PredicateAtom::ObjectSafe(_) => {
bug!("object safe predicate on function: {:#?}", predicate)
}
ty::PredicateKind::ClosureKind(..) => {
ty::PredicateAtom::ClosureKind(..) => {
bug!("closure kind predicate on function: {:#?}", predicate)
}
ty::PredicateKind::Subtype(_) => {
ty::PredicateAtom::Subtype(_) => {
bug!("subtype predicate on function: {:#?}", predicate)
}
&ty::PredicateKind::Trait(pred, constness) => {
ty::PredicateAtom::Trait(pred, constness) => {
if Some(pred.def_id()) == tcx.lang_items().sized_trait() {
continue;
}
match pred.skip_binder().self_ty().kind {
match pred.self_ty().kind {
ty::Param(ref p) => {
// Allow `T: ?const Trait`
if constness == hir::Constness::NotConst

51
src/librustc_privacy/lib.rs
View file

@ -68,10 +68,7 @@ trait DefIdVisitor<'tcx> {
}
}
struct DefIdVisitorSkeleton<'v, 'tcx, V>
where
V: DefIdVisitor<'tcx> + ?Sized,
{
struct DefIdVisitorSkeleton<'v, 'tcx, V: ?Sized> {
def_id_visitor: &'v mut V,
visited_opaque_tys: FxHashSet<DefId>,
dummy: PhantomData<TyCtxt<'tcx>>,
@ -87,34 +84,28 @@ where
|| (!self.def_id_visitor.shallow() && substs.visit_with(self))
}
fn visit_predicate(&mut self, predicate: ty::Predicate<'tcx>) -> bool {
match predicate.skip_binders() {
ty::PredicateAtom::Trait(ty::TraitPredicate { trait_ref }, _) => {
self.visit_trait(trait_ref)
}
ty::PredicateAtom::Projection(ty::ProjectionPredicate { projection_ty, ty }) => {
ty.visit_with(self)
|| self.visit_trait(projection_ty.trait_ref(self.def_id_visitor.tcx()))
}
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(ty, _region)) => {
ty.visit_with(self)
}
ty::PredicateAtom::RegionOutlives(..) => false,
_ => bug!("unexpected predicate: {:?}", predicate),
}
}
fn visit_predicates(&mut self, predicates: ty::GenericPredicates<'tcx>) -> bool {
let ty::GenericPredicates { parent: _, predicates } = predicates;
for (predicate, _span) in predicates {
match predicate.kind() {
ty::PredicateKind::Trait(poly_predicate, _) => {
let ty::TraitPredicate { trait_ref } = poly_predicate.skip_binder();
if self.visit_trait(trait_ref) {
return true;
}
}
ty::PredicateKind::Projection(poly_predicate) => {
let ty::ProjectionPredicate { projection_ty, ty } =
poly_predicate.skip_binder();
if ty.visit_with(self) {
return true;
}
if self.visit_trait(projection_ty.trait_ref(self.def_id_visitor.tcx())) {
return true;
}
}
ty::PredicateKind::TypeOutlives(poly_predicate) => {
let ty::OutlivesPredicate(ty, _region) = poly_predicate.skip_binder();
if ty.visit_with(self) {
return true;
}
}
ty::PredicateKind::RegionOutlives(..) => {}
_ => bug!("unexpected predicate: {:?}", predicate),
for &(predicate, _span) in predicates {
if self.visit_predicate(predicate) {
return true;
}
}
false

27
src/librustc_trait_selection/opaque_types.rs
View file

@ -1154,8 +1154,8 @@ impl<'a, 'tcx> Instantiator<'a, 'tcx> {
debug!("instantiate_opaque_types: ty_var={:?}", ty_var);
for predicate in &bounds.predicates {
if let ty::PredicateKind::Projection(projection) = predicate.kind() {
if projection.skip_binder().ty.references_error() {
if let ty::PredicateAtom::Projection(projection) = predicate.skip_binders() {
if projection.ty.references_error() {
// No point on adding these obligations since there's a type error involved.
return ty_var;
}
@ -1252,17 +1252,17 @@ crate fn required_region_bounds(
traits::elaborate_predicates(tcx, predicates)
.filter_map(|obligation| {
debug!("required_region_bounds(obligation={:?})", obligation);
match obligation.predicate.kind() {
ty::PredicateKind::Projection(..)
| ty::PredicateKind::Trait(..)
| ty::PredicateKind::Subtype(..)
| ty::PredicateKind::WellFormed(..)
| ty::PredicateKind::ObjectSafe(..)
| ty::PredicateKind::ClosureKind(..)
| ty::PredicateKind::RegionOutlives(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => None,
ty::PredicateKind::TypeOutlives(predicate) => {
match obligation.predicate.skip_binders() {
ty::PredicateAtom::Projection(..)
| ty::PredicateAtom::Trait(..)
| ty::PredicateAtom::Subtype(..)
| ty::PredicateAtom::WellFormed(..)
| ty::PredicateAtom::ObjectSafe(..)
| ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::RegionOutlives(..)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => None,
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(ref t, ref r)) => {
// Search for a bound of the form `erased_self_ty
// : 'a`, but be wary of something like `for<'a>
// erased_self_ty : 'a` (we interpret a
@ -1272,7 +1272,6 @@ crate fn required_region_bounds(
// it's kind of a moot point since you could never
// construct such an object, but this seems
// correct even if that code changes).
let ty::OutlivesPredicate(ref t, ref r) = predicate.skip_binder();
if t == &erased_self_ty && !r.has_escaping_bound_vars() {
Some(*r)
} else {

46
src/librustc_trait_selection/traits/auto_trait.rs
View file

@ -344,8 +344,7 @@ impl AutoTraitFinder<'tcx> {
already_visited.remove(&pred);
self.add_user_pred(
&mut user_computed_preds,
ty::PredicateKind::Trait(pred, hir::Constness::NotConst)
.to_predicate(self.tcx),
pred.without_const().to_predicate(self.tcx),
);
predicates.push_back(pred);
} else {
@ -408,21 +407,21 @@ impl AutoTraitFinder<'tcx> {
/// under which a type implements an auto trait. A trait predicate involving
/// a HRTB means that the type needs to work with any choice of lifetime,
/// not just one specific lifetime (e.g., `'static`).
fn add_user_pred<'c>(
fn add_user_pred(
&self,
user_computed_preds: &mut FxHashSet<ty::Predicate<'c>>,
new_pred: ty::Predicate<'c>,
user_computed_preds: &mut FxHashSet<ty::Predicate<'tcx>>,
new_pred: ty::Predicate<'tcx>,
) {
let mut should_add_new = true;
user_computed_preds.retain(|&old_pred| {
if let (
ty::PredicateKind::Trait(new_trait, _),
ty::PredicateKind::Trait(old_trait, _),
) = (new_pred.kind(), old_pred.kind())
ty::PredicateAtom::Trait(new_trait, _),
ty::PredicateAtom::Trait(old_trait, _),
) = (new_pred.skip_binders(), old_pred.skip_binders())
{
if new_trait.def_id() == old_trait.def_id() {
let new_substs = new_trait.skip_binder().trait_ref.substs;
let old_substs = old_trait.skip_binder().trait_ref.substs;
let new_substs = new_trait.trait_ref.substs;
let old_substs = old_trait.trait_ref.substs;
if !new_substs.types().eq(old_substs.types()) {
// We can't compare lifetimes if the types are different,
@ -618,11 +617,12 @@ impl AutoTraitFinder<'tcx> {
) -> bool {
let dummy_cause = ObligationCause::dummy();
for (obligation, mut predicate) in nested.map(|o| (o.clone(), o.predicate)) {
let is_new_pred = fresh_preds.insert(self.clean_pred(select.infcx(), predicate));
for obligation in nested {
let is_new_pred =
fresh_preds.insert(self.clean_pred(select.infcx(), obligation.predicate));
// Resolve any inference variables that we can, to help selection succeed
predicate = select.infcx().resolve_vars_if_possible(&predicate);
let predicate = select.infcx().resolve_vars_if_possible(&obligation.predicate);
// We only add a predicate as a user-displayable bound if
// it involves a generic parameter, and doesn't contain
@ -636,17 +636,19 @@ impl AutoTraitFinder<'tcx> {
//
// We check this by calling is_of_param on the relevant types
// from the various possible predicates
match predicate.kind() {
&ty::PredicateKind::Trait(p, _) => {
if self.is_param_no_infer(p.skip_binder().trait_ref.substs)
match predicate.skip_binders() {
ty::PredicateAtom::Trait(p, _) => {
if self.is_param_no_infer(p.trait_ref.substs)
&& !only_projections
&& is_new_pred
{
self.add_user_pred(computed_preds, predicate);
}
predicates.push_back(p);
predicates.push_back(ty::Binder::bind(p));
}
&ty::PredicateKind::Projection(p) => {
ty::PredicateAtom::Projection(p) => {
let p = ty::Binder::bind(p);
debug!(
"evaluate_nested_obligations: examining projection predicate {:?}",
predicate
@ -758,7 +760,7 @@ impl AutoTraitFinder<'tcx> {
}
}
Ok(None) => {
// It's ok not to make progress when hvave no inference variables -
// It's ok not to make progress when have no inference variables -
// in that case, we were only performing unifcation to check if an
// error occurred (which would indicate that it's impossible for our
// type to implement the auto trait).
@ -771,12 +773,14 @@ impl AutoTraitFinder<'tcx> {
}
}
}
&ty::PredicateKind::RegionOutlives(binder) => {
ty::PredicateAtom::RegionOutlives(binder) => {
let binder = ty::Binder::bind(binder);
if select.infcx().region_outlives_predicate(&dummy_cause, binder).is_err() {
return false;
}
}
&ty::PredicateKind::TypeOutlives(binder) => {
ty::PredicateAtom::TypeOutlives(binder) => {
let binder = ty::Binder::bind(binder);
match (
binder.no_bound_vars(),
binder.map_bound_ref(|pred| pred.0).no_bound_vars(),

80
src/librustc_trait_selection/traits/error_reporting/mod.rs
View file

@ -255,9 +255,11 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
.emit();
return;
}
match obligation.predicate.kind() {
ty::PredicateKind::Trait(ref trait_predicate, _) => {
let trait_predicate = self.resolve_vars_if_possible(trait_predicate);
match obligation.predicate.skip_binders() {
ty::PredicateAtom::Trait(trait_predicate, _) => {
let trait_predicate = ty::Binder::bind(trait_predicate);
let trait_predicate = self.resolve_vars_if_possible(&trait_predicate);
if self.tcx.sess.has_errors() && trait_predicate.references_error() {
return;
@ -503,14 +505,8 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
);
trait_pred
});
let unit_obligation = Obligation {
predicate: ty::PredicateKind::Trait(
predicate,
hir::Constness::NotConst,
)
.to_predicate(self.tcx),
..obligation.clone()
};
let unit_obligation =
obligation.with(predicate.without_const().to_predicate(tcx));
if self.predicate_may_hold(&unit_obligation) {
err.note(
"the trait is implemented for `()`. \
@ -526,15 +522,16 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
err
}
ty::PredicateKind::Subtype(ref predicate) => {
ty::PredicateAtom::Subtype(predicate) => {
// Errors for Subtype predicates show up as
// `FulfillmentErrorCode::CodeSubtypeError`,
// not selection error.
span_bug!(span, "subtype requirement gave wrong error: `{:?}`", predicate)
}
ty::PredicateKind::RegionOutlives(ref predicate) => {
let predicate = self.resolve_vars_if_possible(predicate);
ty::PredicateAtom::RegionOutlives(predicate) => {
let predicate = ty::Binder::bind(predicate);
let predicate = self.resolve_vars_if_possible(&predicate);
let err = self
.region_outlives_predicate(&obligation.cause, predicate)
.err()
@ -549,7 +546,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
)
}
ty::PredicateKind::Projection(..) | ty::PredicateKind::TypeOutlives(..) => {
ty::PredicateAtom::Projection(..) | ty::PredicateAtom::TypeOutlives(..) => {
let predicate = self.resolve_vars_if_possible(&obligation.predicate);
struct_span_err!(
self.tcx.sess,
@ -560,12 +557,12 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
)
}
&ty::PredicateKind::ObjectSafe(trait_def_id) => {
ty::PredicateAtom::ObjectSafe(trait_def_id) => {
let violations = self.tcx.object_safety_violations(trait_def_id);
report_object_safety_error(self.tcx, span, trait_def_id, violations)
}
&ty::PredicateKind::ClosureKind(closure_def_id, closure_substs, kind) => {
ty::PredicateAtom::ClosureKind(closure_def_id, closure_substs, kind) => {
let found_kind = self.closure_kind(closure_substs).unwrap();
let closure_span =
self.tcx.sess.source_map().guess_head_span(
@ -624,7 +621,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
return;
}
ty::PredicateKind::WellFormed(ty) => {
ty::PredicateAtom::WellFormed(ty) => {
if !self.tcx.sess.opts.debugging_opts.chalk {
// WF predicates cannot themselves make
// errors. They can only block due to
@ -642,7 +639,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
}
}
ty::PredicateKind::ConstEvaluatable(..) => {
ty::PredicateAtom::ConstEvaluatable(..) => {
// Errors for `ConstEvaluatable` predicates show up as
// `SelectionError::ConstEvalFailure`,
// not `Unimplemented`.
@ -653,7 +650,7 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
)
}
ty::PredicateKind::ConstEquate(..) => {
ty::PredicateAtom::ConstEquate(..) => {
// Errors for `ConstEquate` predicates show up as
// `SelectionError::ConstEvalFailure`,
// not `Unimplemented`.
@ -1089,8 +1086,11 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
return true;
}
let (cond, error) = match (cond.kind(), error.kind()) {
(ty::PredicateKind::Trait(..), ty::PredicateKind::Trait(error, _)) => (cond, error),
// FIXME: It should be possible to deal with `ForAll` in a cleaner way.
let (cond, error) = match (cond.skip_binders(), error.skip_binders()) {
(ty::PredicateAtom::Trait(..), ty::PredicateAtom::Trait(error, _)) => {
(cond, ty::Binder::bind(error))
}
_ => {
// FIXME: make this work in other cases too.
return false;
@ -1098,9 +1098,9 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
};
for obligation in super::elaborate_predicates(self.tcx, std::iter::once(cond)) {
if let ty::PredicateKind::Trait(implication, _) = obligation.predicate.kind() {
if let ty::PredicateAtom::Trait(implication, _) = obligation.predicate.skip_binders() {
let error = error.to_poly_trait_ref();
let implication = implication.to_poly_trait_ref();
let implication = ty::Binder::bind(implication.trait_ref);
// FIXME: I'm just not taking associated types at all here.
// Eventually I'll need to implement param-env-aware
// `Γ₁ ⊦ φ₁ => Γ₂ ⊦ φ₂` logic.
@ -1178,12 +1178,12 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
//
// this can fail if the problem was higher-ranked, in which
// cause I have no idea for a good error message.
if let ty::PredicateKind::Projection(ref data) = predicate.kind() {
if let ty::PredicateAtom::Projection(data) = predicate.skip_binders() {
let mut selcx = SelectionContext::new(self);
let (data, _) = self.replace_bound_vars_with_fresh_vars(
obligation.cause.span,
infer::LateBoundRegionConversionTime::HigherRankedType,
data,
&ty::Binder::bind(data),
);
let mut obligations = vec![];
let normalized_ty = super::normalize_projection_type(
@ -1470,9 +1470,9 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
return;
}
let mut err = match predicate.kind() {
ty::PredicateKind::Trait(ref data, _) => {
let trait_ref = data.to_poly_trait_ref();
let mut err = match predicate.skip_binders() {
ty::PredicateAtom::Trait(data, _) => {
let trait_ref = ty::Binder::bind(data.trait_ref);
let self_ty = trait_ref.skip_binder().self_ty();
debug!("self_ty {:?} {:?} trait_ref {:?}", self_ty, self_ty.kind, trait_ref);
@ -1570,7 +1570,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
err
}
ty::PredicateKind::WellFormed(arg) => {
ty::PredicateAtom::WellFormed(arg) => {
// Same hacky approach as above to avoid deluging user
// with error messages.
if arg.references_error() || self.tcx.sess.has_errors() {
@ -1590,20 +1590,20 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
}
}
ty::PredicateKind::Subtype(ref data) => {
ty::PredicateAtom::Subtype(data) => {
if data.references_error() || self.tcx.sess.has_errors() {
// no need to overload user in such cases
return;
}
let SubtypePredicate { a_is_expected: _, a, b } = data.skip_binder();
let SubtypePredicate { a_is_expected: _, a, b } = data;
// both must be type variables, or the other would've been instantiated
assert!(a.is_ty_var() && b.is_ty_var());
self.need_type_info_err(body_id, span, a, ErrorCode::E0282)
}
ty::PredicateKind::Projection(ref data) => {
let trait_ref = data.to_poly_trait_ref(self.tcx);
ty::PredicateAtom::Projection(data) => {
let trait_ref = ty::Binder::bind(data).to_poly_trait_ref(self.tcx);
let self_ty = trait_ref.skip_binder().self_ty();
let ty = data.skip_binder().ty;
let ty = data.ty;
if predicate.references_error() {
return;
}
@ -1724,16 +1724,16 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
obligation: &PredicateObligation<'tcx>,
) {
let (pred, item_def_id, span) =
match (obligation.predicate.kind(), &obligation.cause.code.peel_derives()) {
match (obligation.predicate.skip_binders(), obligation.cause.code.peel_derives()) {
(
ty::PredicateKind::Trait(pred, _),
ObligationCauseCode::BindingObligation(item_def_id, span),
ty::PredicateAtom::Trait(pred, _),
&ObligationCauseCode::BindingObligation(item_def_id, span),
) => (pred, item_def_id, span),
_ => return,
};
let node = match (
self.tcx.hir().get_if_local(*item_def_id),
self.tcx.hir().get_if_local(item_def_id),
Some(pred.def_id()) == self.tcx.lang_items().sized_trait(),
) {
(Some(node), true) => node,
@ -1744,7 +1744,7 @@ impl<'a, 'tcx> InferCtxtPrivExt<'tcx> for InferCtxt<'a, 'tcx> {
None => return,
};
for param in generics.params {
if param.span != *span
if param.span != span
|| param.bounds.iter().any(|bound| {
bound.trait_ref().and_then(|trait_ref| trait_ref.trait_def_id())
== self.tcx.lang_items().sized_trait()

6
src/librustc_trait_selection/traits/error_reporting/suggestions.rs
View file

@ -1300,10 +1300,8 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> {
// the type. The last generator (`outer_generator` below) has information about where the
// bound was introduced. At least one generator should be present for this diagnostic to be
// modified.
let (mut trait_ref, mut target_ty) = match obligation.predicate.kind() {
ty::PredicateKind::Trait(p, _) => {
(Some(p.skip_binder().trait_ref), Some(p.skip_binder().self_ty()))
}
let (mut trait_ref, mut target_ty) = match obligation.predicate.skip_binders() {
ty::PredicateAtom::Trait(p, _) => (Some(p.trait_ref), Some(p.self_ty())),
_ => (None, None),
};
let mut generator = None;

514
src/librustc_trait_selection/traits/fulfill.rs
View file

@ -3,10 +3,11 @@ use rustc_data_structures::obligation_forest::ProcessResult;
use rustc_data_structures::obligation_forest::{DoCompleted, Error, ForestObligation};
use rustc_data_structures::obligation_forest::{ObligationForest, ObligationProcessor};
use rustc_errors::ErrorReported;
use rustc_infer::traits::{TraitEngine, TraitEngineExt as _};
use rustc_infer::traits::{TraitEngine, TraitEngineExt as _, TraitObligation};
use rustc_middle::mir::interpret::ErrorHandled;
use rustc_middle::ty::error::ExpectedFound;
use rustc_middle::ty::{self, Const, ToPolyTraitRef, Ty, TypeFoldable};
use rustc_middle::ty::ToPredicate;
use rustc_middle::ty::{self, Binder, Const, Ty, TypeFoldable};
use std::marker::PhantomData;
use super::project;
@ -20,6 +21,7 @@ use super::{FulfillmentError, FulfillmentErrorCode};
use super::{ObligationCause, PredicateObligation};
use crate::traits::error_reporting::InferCtxtExt as _;
use crate::traits::project::PolyProjectionObligation;
use crate::traits::query::evaluate_obligation::InferCtxtExt as _;
impl<'tcx> ForestObligation for PendingPredicateObligation<'tcx> {
@ -318,267 +320,222 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> {
let infcx = self.selcx.infcx();
match obligation.predicate.kind() {
ty::PredicateKind::Trait(ref data, _) => {
let trait_obligation = obligation.with(*data);
ty::PredicateKind::ForAll(binder) => match binder.skip_binder() {
// Evaluation will discard candidates using the leak check.
// This means we need to pass it the bound version of our
// predicate.
ty::PredicateAtom::Trait(trait_ref, _constness) => {
let trait_obligation = obligation.with(Binder::bind(trait_ref));
if obligation.predicate.is_global() {
// no type variables present, can use evaluation for better caching.
// FIXME: consider caching errors too.
if infcx.predicate_must_hold_considering_regions(&obligation) {
debug!(
"selecting trait `{:?}` at depth {} evaluated to holds",
data, obligation.recursion_depth
);
return ProcessResult::Changed(vec![]);
self.process_trait_obligation(
obligation,
trait_obligation,
&mut pending_obligation.stalled_on,
)
}
ty::PredicateAtom::Projection(data) => {
let project_obligation = obligation.with(Binder::bind(data));
self.process_projection_obligation(
project_obligation,
&mut pending_obligation.stalled_on,
)
}
ty::PredicateAtom::RegionOutlives(_)
| ty::PredicateAtom::TypeOutlives(_)
| ty::PredicateAtom::WellFormed(_)
| ty::PredicateAtom::ObjectSafe(_)
| ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::Subtype(_)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => {
let (pred, _) = infcx.replace_bound_vars_with_placeholders(binder);
ProcessResult::Changed(mk_pending(vec![
obligation.with(pred.to_predicate(self.selcx.tcx())),
]))
}
},
&ty::PredicateKind::Atom(atom) => match atom {
ty::PredicateAtom::Trait(ref data, _) => {
let trait_obligation = obligation.with(Binder::dummy(*data));
self.process_trait_obligation(
obligation,
trait_obligation,
&mut pending_obligation.stalled_on,
)
}
ty::PredicateAtom::RegionOutlives(data) => {
match infcx.region_outlives_predicate(&obligation.cause, Binder::dummy(data)) {
Ok(()) => ProcessResult::Changed(vec![]),
Err(_) => ProcessResult::Error(CodeSelectionError(Unimplemented)),
}
}
match self.selcx.select(&trait_obligation) {
Ok(Some(impl_source)) => {
debug!(
"selecting trait `{:?}` at depth {} yielded Ok(Some)",
data, obligation.recursion_depth
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(t_a, r_b)) => {
if self.register_region_obligations {
self.selcx.infcx().register_region_obligation_with_cause(
t_a,
r_b,
&obligation.cause,
);
ProcessResult::Changed(mk_pending(impl_source.nested_obligations()))
}
Ok(None) => {
debug!(
"selecting trait `{:?}` at depth {} yielded Ok(None)",
data, obligation.recursion_depth
);
// This is a bit subtle: for the most part, the
// only reason we can fail to make progress on
// trait selection is because we don't have enough
// information about the types in the trait.
pending_obligation.stalled_on =
trait_ref_infer_vars(self.selcx, data.to_poly_trait_ref());
debug!(
"process_predicate: pending obligation {:?} now stalled on {:?}",
infcx.resolve_vars_if_possible(obligation),
pending_obligation.stalled_on
);
ProcessResult::Unchanged
}
Err(selection_err) => {
info!(
"selecting trait `{:?}` at depth {} yielded Err",
data, obligation.recursion_depth
);
ProcessResult::Error(CodeSelectionError(selection_err))
}
ProcessResult::Changed(vec![])
}
}
&ty::PredicateKind::RegionOutlives(binder) => {
match infcx.region_outlives_predicate(&obligation.cause, binder) {
Ok(()) => ProcessResult::Changed(vec![]),
Err(_) => ProcessResult::Error(CodeSelectionError(Unimplemented)),
ty::PredicateAtom::Projection(ref data) => {
let project_obligation = obligation.with(Binder::dummy(*data));
self.process_projection_obligation(
project_obligation,
&mut pending_obligation.stalled_on,
)
}
}
ty::PredicateKind::TypeOutlives(ref binder) => {
// Check if there are higher-ranked vars.
match binder.no_bound_vars() {
// If there are, inspect the underlying type further.
None => {
// Convert from `Binder<OutlivesPredicate<Ty, Region>>` to `Binder<Ty>`.
let binder = binder.map_bound_ref(|pred| pred.0);
// Check if the type has any bound vars.
match binder.no_bound_vars() {
// If so, this obligation is an error (for now). Eventually we should be
// able to support additional cases here, like `for<'a> &'a str: 'a`.
// NOTE: this is duplicate-implemented between here and fulfillment.
None => ProcessResult::Error(CodeSelectionError(Unimplemented)),
// Otherwise, we have something of the form
// `for<'a> T: 'a where 'a not in T`, which we can treat as
// `T: 'static`.
Some(t_a) => {
let r_static = self.selcx.tcx().lifetimes.re_static;
if self.register_region_obligations {
self.selcx.infcx().register_region_obligation_with_cause(
t_a,
r_static,
&obligation.cause,
);
}
ProcessResult::Changed(vec![])
}
}
}
// If there aren't, register the obligation.
Some(ty::OutlivesPredicate(t_a, r_b)) => {
if self.register_region_obligations {
self.selcx.infcx().register_region_obligation_with_cause(
t_a,
r_b,
&obligation.cause,
);
}
ty::PredicateAtom::ObjectSafe(trait_def_id) => {
if !self.selcx.tcx().is_object_safe(trait_def_id) {
ProcessResult::Error(CodeSelectionError(Unimplemented))
} else {
ProcessResult::Changed(vec![])
}
}
}
ty::PredicateKind::Projection(ref data) => {
let project_obligation = obligation.with(*data);
match project::poly_project_and_unify_type(self.selcx, &project_obligation) {
Ok(None) => {
let tcx = self.selcx.tcx();
pending_obligation.stalled_on =
trait_ref_infer_vars(self.selcx, data.to_poly_trait_ref(tcx));
ProcessResult::Unchanged
ty::PredicateAtom::ClosureKind(_, closure_substs, kind) => {
match self.selcx.infcx().closure_kind(closure_substs) {
Some(closure_kind) => {
if closure_kind.extends(kind) {
ProcessResult::Changed(vec![])
} else {
ProcessResult::Error(CodeSelectionError(Unimplemented))
}
}
None => ProcessResult::Unchanged,
}
Ok(Some(os)) => ProcessResult::Changed(mk_pending(os)),
Err(e) => ProcessResult::Error(CodeProjectionError(e)),
}
}
&ty::PredicateKind::ObjectSafe(trait_def_id) => {
if !self.selcx.tcx().is_object_safe(trait_def_id) {
ProcessResult::Error(CodeSelectionError(Unimplemented))
} else {
ProcessResult::Changed(vec![])
ty::PredicateAtom::WellFormed(arg) => {
match wf::obligations(
self.selcx.infcx(),
obligation.param_env,
obligation.cause.body_id,
arg,
obligation.cause.span,
) {
None => {
pending_obligation.stalled_on =
vec![TyOrConstInferVar::maybe_from_generic_arg(arg).unwrap()];
ProcessResult::Unchanged
}
Some(os) => ProcessResult::Changed(mk_pending(os)),
}
}
}
&ty::PredicateKind::ClosureKind(_, closure_substs, kind) => {
match self.selcx.infcx().closure_kind(closure_substs) {
Some(closure_kind) => {
if closure_kind.extends(kind) {
ProcessResult::Changed(vec![])
ty::PredicateAtom::Subtype(subtype) => {
match self.selcx.infcx().subtype_predicate(
&obligation.cause,
obligation.param_env,
Binder::dummy(subtype),
) {
None => {
// None means that both are unresolved.
pending_obligation.stalled_on = vec![
TyOrConstInferVar::maybe_from_ty(subtype.a).unwrap(),
TyOrConstInferVar::maybe_from_ty(subtype.b).unwrap(),
];
ProcessResult::Unchanged
}
Some(Ok(ok)) => ProcessResult::Changed(mk_pending(ok.obligations)),
Some(Err(err)) => {
let expected_found =
ExpectedFound::new(subtype.a_is_expected, subtype.a, subtype.b);
ProcessResult::Error(FulfillmentErrorCode::CodeSubtypeError(
expected_found,
err,
))
}
}
}
ty::PredicateAtom::ConstEvaluatable(def_id, substs) => {
match self.selcx.infcx().const_eval_resolve(
obligation.param_env,
def_id,
substs,
None,
Some(obligation.cause.span),
) {
Ok(_) => ProcessResult::Changed(vec![]),
Err(err) => ProcessResult::Error(CodeSelectionError(ConstEvalFailure(err))),
}
}
ty::PredicateAtom::ConstEquate(c1, c2) => {
debug!("equating consts: c1={:?} c2={:?}", c1, c2);
let stalled_on = &mut pending_obligation.stalled_on;
let mut evaluate = |c: &'tcx Const<'tcx>| {
if let ty::ConstKind::Unevaluated(def, substs, promoted) = c.val {
match self.selcx.infcx().const_eval_resolve(
obligation.param_env,
def,
substs,
promoted,
Some(obligation.cause.span),
) {
Ok(val) => Ok(Const::from_value(self.selcx.tcx(), val, c.ty)),
Err(ErrorHandled::TooGeneric) => {
stalled_on.append(
&mut substs
.types()
.filter_map(|ty| TyOrConstInferVar::maybe_from_ty(ty))
.collect(),
);
Err(ErrorHandled::TooGeneric)
}
Err(err) => Err(err),
}
} else {
ProcessResult::Error(CodeSelectionError(Unimplemented))
Ok(c)
}
}
None => ProcessResult::Unchanged,
}
}
};
&ty::PredicateKind::WellFormed(arg) => {
match wf::obligations(
self.selcx.infcx(),
obligation.param_env,
obligation.cause.body_id,
arg,
obligation.cause.span,
) {
None => {
pending_obligation.stalled_on =
vec![TyOrConstInferVar::maybe_from_generic_arg(arg).unwrap()];
ProcessResult::Unchanged
}
Some(os) => ProcessResult::Changed(mk_pending(os)),
}
}
&ty::PredicateKind::Subtype(subtype) => {
match self.selcx.infcx().subtype_predicate(
&obligation.cause,
obligation.param_env,
subtype,
) {
None => {
// None means that both are unresolved.
pending_obligation.stalled_on = vec![
TyOrConstInferVar::maybe_from_ty(subtype.skip_binder().a).unwrap(),
TyOrConstInferVar::maybe_from_ty(subtype.skip_binder().b).unwrap(),
];
ProcessResult::Unchanged
}
Some(Ok(ok)) => ProcessResult::Changed(mk_pending(ok.obligations)),
Some(Err(err)) => {
let expected_found = ExpectedFound::new(
subtype.skip_binder().a_is_expected,
subtype.skip_binder().a,
subtype.skip_binder().b,
);
ProcessResult::Error(FulfillmentErrorCode::CodeSubtypeError(
expected_found,
err,
))
}
}
}
&ty::PredicateKind::ConstEvaluatable(def_id, substs) => {
match self.selcx.infcx().const_eval_resolve(
obligation.param_env,
def_id,
substs,
None,
Some(obligation.cause.span),
) {
Ok(_) => ProcessResult::Changed(vec![]),
Err(err) => ProcessResult::Error(CodeSelectionError(ConstEvalFailure(err))),
}
}
ty::PredicateKind::ConstEquate(c1, c2) => {
debug!("equating consts: c1={:?} c2={:?}", c1, c2);
let stalled_on = &mut pending_obligation.stalled_on;
let mut evaluate = |c: &'tcx Const<'tcx>| {
if let ty::ConstKind::Unevaluated(def, substs, promoted) = c.val {
match self.selcx.infcx().const_eval_resolve(
obligation.param_env,
def,
substs,
promoted,
Some(obligation.cause.span),
) {
Ok(val) => Ok(Const::from_value(self.selcx.tcx(), val, c.ty)),
Err(ErrorHandled::TooGeneric) => {
stalled_on.append(
&mut substs
.types()
.filter_map(|ty| TyOrConstInferVar::maybe_from_ty(ty))
.collect(),
);
Err(ErrorHandled::TooGeneric)
}
Err(err) => Err(err),
}
} else {
Ok(c)
}
};
match (evaluate(c1), evaluate(c2)) {
(Ok(c1), Ok(c2)) => {
match self
.selcx
.infcx()
.at(&obligation.cause, obligation.param_env)
.eq(c1, c2)
{
Ok(_) => ProcessResult::Changed(vec![]),
Err(err) => {
ProcessResult::Error(FulfillmentErrorCode::CodeConstEquateError(
ExpectedFound::new(true, c1, c2),
err,
))
match (evaluate(c1), evaluate(c2)) {
(Ok(c1), Ok(c2)) => {
match self
.selcx
.infcx()
.at(&obligation.cause, obligation.param_env)
.eq(c1, c2)
{
Ok(_) => ProcessResult::Changed(vec![]),
Err(err) => ProcessResult::Error(
FulfillmentErrorCode::CodeConstEquateError(
ExpectedFound::new(true, c1, c2),
err,
),
),
}
}
}
(Err(ErrorHandled::Reported(ErrorReported)), _)
| (_, Err(ErrorHandled::Reported(ErrorReported))) => ProcessResult::Error(
CodeSelectionError(ConstEvalFailure(ErrorHandled::Reported(ErrorReported))),
),
(Err(ErrorHandled::Linted), _) | (_, Err(ErrorHandled::Linted)) => span_bug!(
obligation.cause.span(self.selcx.tcx()),
"ConstEquate: const_eval_resolve returned an unexpected error"
),
(Err(ErrorHandled::TooGeneric), _) | (_, Err(ErrorHandled::TooGeneric)) => {
ProcessResult::Unchanged
(Err(ErrorHandled::Reported(ErrorReported)), _)
| (_, Err(ErrorHandled::Reported(ErrorReported))) => {
ProcessResult::Error(CodeSelectionError(ConstEvalFailure(
ErrorHandled::Reported(ErrorReported),
)))
}
(Err(ErrorHandled::Linted), _) | (_, Err(ErrorHandled::Linted)) => {
span_bug!(
obligation.cause.span(self.selcx.tcx()),
"ConstEquate: const_eval_resolve returned an unexpected error"
)
}
(Err(ErrorHandled::TooGeneric), _) | (_, Err(ErrorHandled::TooGeneric)) => {
ProcessResult::Unchanged
}
}
}
}
},
}
}
@ -598,6 +555,87 @@ impl<'a, 'b, 'tcx> ObligationProcessor for FulfillProcessor<'a, 'b, 'tcx> {
}
}
impl<'a, 'b, 'tcx> FulfillProcessor<'a, 'b, 'tcx> {
fn process_trait_obligation(
&mut self,
obligation: &PredicateObligation<'tcx>,
trait_obligation: TraitObligation<'tcx>,
stalled_on: &mut Vec<TyOrConstInferVar<'tcx>>,
) -> ProcessResult<PendingPredicateObligation<'tcx>, FulfillmentErrorCode<'tcx>> {
let infcx = self.selcx.infcx();
if obligation.predicate.is_global() {
// no type variables present, can use evaluation for better caching.
// FIXME: consider caching errors too.
if infcx.predicate_must_hold_considering_regions(obligation) {
debug!(
"selecting trait `{:?}` at depth {} evaluated to holds",
obligation.predicate, obligation.recursion_depth
);
return ProcessResult::Changed(vec![]);
}
}
match self.selcx.select(&trait_obligation) {
Ok(Some(impl_source)) => {
debug!(
"selecting trait `{:?}` at depth {} yielded Ok(Some)",
trait_obligation.predicate, obligation.recursion_depth
);
ProcessResult::Changed(mk_pending(impl_source.nested_obligations()))
}
Ok(None) => {
debug!(
"selecting trait `{:?}` at depth {} yielded Ok(None)",
trait_obligation.predicate, obligation.recursion_depth
);
// This is a bit subtle: for the most part, the
// only reason we can fail to make progress on
// trait selection is because we don't have enough
// information about the types in the trait.
*stalled_on = trait_ref_infer_vars(
self.selcx,
trait_obligation.predicate.map_bound(|pred| pred.trait_ref),
);
debug!(
"process_predicate: pending obligation {:?} now stalled on {:?}",
infcx.resolve_vars_if_possible(obligation),
stalled_on
);
ProcessResult::Unchanged
}
Err(selection_err) => {
info!(
"selecting trait `{:?}` at depth {} yielded Err",
trait_obligation.predicate, obligation.recursion_depth
);
ProcessResult::Error(CodeSelectionError(selection_err))
}
}
}
fn process_projection_obligation(
&mut self,
project_obligation: PolyProjectionObligation<'tcx>,
stalled_on: &mut Vec<TyOrConstInferVar<'tcx>>,
) -> ProcessResult<PendingPredicateObligation<'tcx>, FulfillmentErrorCode<'tcx>> {
match project::poly_project_and_unify_type(self.selcx, &project_obligation) {
Ok(None) => {
*stalled_on = trait_ref_infer_vars(
self.selcx,
project_obligation.predicate.to_poly_trait_ref(self.selcx.tcx()),
);
ProcessResult::Unchanged
}
Ok(Some(os)) => ProcessResult::Changed(mk_pending(os)),
Err(e) => ProcessResult::Error(CodeProjectionError(e)),
}
}
}
/// Returns the set of inference variables contained in a trait ref.
fn trait_ref_infer_vars<'a, 'tcx>(
selcx: &mut SelectionContext<'a, 'tcx>,
@ -606,7 +644,7 @@ fn trait_ref_infer_vars<'a, 'tcx>(
selcx
.infcx()
.resolve_vars_if_possible(&trait_ref)
.skip_binder() // ok b/c this check doesn't care about regions
.skip_binder()
.substs
.iter()
// FIXME(eddyb) try using `skip_current_subtree` to skip everything that

4
src/librustc_trait_selection/traits/mod.rs
View file

@ -328,8 +328,8 @@ pub fn normalize_param_env_or_error<'tcx>(
// This works fairly well because trait matching does not actually care about param-env
// TypeOutlives predicates - these are normally used by regionck.
let outlives_predicates: Vec<_> = predicates
.drain_filter(|predicate| match predicate.kind() {
ty::PredicateKind::TypeOutlives(..) => true,
.drain_filter(|predicate| match predicate.skip_binders() {
ty::PredicateAtom::TypeOutlives(..) => true,
_ => false,
})
.collect();

58
src/librustc_trait_selection/traits/object_safety.rs
View file

@ -245,16 +245,12 @@ fn predicates_reference_self(
.iter()
.map(|(predicate, sp)| (predicate.subst_supertrait(tcx, &trait_ref), sp))
.filter_map(|(predicate, &sp)| {
match predicate.kind() {
ty::PredicateKind::Trait(ref data, _) => {
match predicate.skip_binders() {
ty::PredicateAtom::Trait(ref data, _) => {
// In the case of a trait predicate, we can skip the "self" type.
if data.skip_binder().trait_ref.substs[1..].iter().any(has_self_ty) {
Some(sp)
} else {
None
}
if data.trait_ref.substs[1..].iter().any(has_self_ty) { Some(sp) } else { None }
}
ty::PredicateKind::Projection(ref data) => {
ty::PredicateAtom::Projection(ref data) => {
// And similarly for projections. This should be redundant with
// the previous check because any projection should have a
// matching `Trait` predicate with the same inputs, but we do
@ -267,23 +263,20 @@ fn predicates_reference_self(
//
// This is ALT2 in issue #56288, see that for discussion of the
// possible alternatives.
if data.skip_binder().projection_ty.trait_ref(tcx).substs[1..]
.iter()
.any(has_self_ty)
{
if data.projection_ty.trait_ref(tcx).substs[1..].iter().any(has_self_ty) {
Some(sp)
} else {
None
}
}
ty::PredicateKind::WellFormed(..)
| ty::PredicateKind::ObjectSafe(..)
| ty::PredicateKind::TypeOutlives(..)
| ty::PredicateKind::RegionOutlives(..)
| ty::PredicateKind::ClosureKind(..)
| ty::PredicateKind::Subtype(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => None,
ty::PredicateAtom::WellFormed(..)
| ty::PredicateAtom::ObjectSafe(..)
| ty::PredicateAtom::TypeOutlives(..)
| ty::PredicateAtom::RegionOutlives(..)
| ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::Subtype(..)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => None,
}
})
.collect()
@ -305,20 +298,19 @@ fn generics_require_sized_self(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
let predicates = tcx.predicates_of(def_id);
let predicates = predicates.instantiate_identity(tcx).predicates;
elaborate_predicates(tcx, predicates.into_iter()).any(|obligation| {
match obligation.predicate.kind() {
ty::PredicateKind::Trait(ref trait_pred, _) => {
trait_pred.def_id() == sized_def_id
&& trait_pred.skip_binder().self_ty().is_param(0)
match obligation.predicate.skip_binders() {
ty::PredicateAtom::Trait(ref trait_pred, _) => {
trait_pred.def_id() == sized_def_id && trait_pred.self_ty().is_param(0)
}
ty::PredicateKind::Projection(..)
| ty::PredicateKind::Subtype(..)
| ty::PredicateKind::RegionOutlives(..)
| ty::PredicateKind::WellFormed(..)
| ty::PredicateKind::ObjectSafe(..)
| ty::PredicateKind::ClosureKind(..)
| ty::PredicateKind::TypeOutlives(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => false,
ty::PredicateAtom::Projection(..)
| ty::PredicateAtom::Subtype(..)
| ty::PredicateAtom::RegionOutlives(..)
| ty::PredicateAtom::WellFormed(..)
| ty::PredicateAtom::ObjectSafe(..)
| ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::TypeOutlives(..)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => false,
}
})
}

46
src/librustc_trait_selection/traits/project.rs
View file

@ -664,23 +664,25 @@ fn prune_cache_value_obligations<'a, 'tcx>(
let mut obligations: Vec<_> = result
.obligations
.iter()
.filter(|obligation| match obligation.predicate.kind() {
// We found a `T: Foo<X = U>` predicate, let's check
// if `U` references any unresolved type
// variables. In principle, we only care if this
// projection can help resolve any of the type
// variables found in `result.value` -- but we just
// check for any type variables here, for fear of
// indirect obligations (e.g., we project to `?0`,
// but we have `T: Foo<X = ?1>` and `?1: Bar<X =
// ?0>`).
ty::PredicateKind::Projection(ref data) => {
infcx.unresolved_type_vars(&data.ty()).is_some()
}
.filter(|obligation| {
match obligation.predicate.skip_binders() {
// We found a `T: Foo<X = U>` predicate, let's check
// if `U` references any unresolved type
// variables. In principle, we only care if this
// projection can help resolve any of the type
// variables found in `result.value` -- but we just
// check for any type variables here, for fear of
// indirect obligations (e.g., we project to `?0`,
// but we have `T: Foo<X = ?1>` and `?1: Bar<X =
// ?0>`).
ty::PredicateAtom::Projection(data) => {
infcx.unresolved_type_vars(&ty::Binder::bind(data.ty)).is_some()
}
// We are only interested in `T: Foo<X = U>` predicates, whre
// `U` references one of `unresolved_type_vars`. =)
_ => false,
// We are only interested in `T: Foo<X = U>` predicates, whre
// `U` references one of `unresolved_type_vars`. =)
_ => false,
}
})
.cloned()
.collect();
@ -931,7 +933,8 @@ fn assemble_candidates_from_predicates<'cx, 'tcx>(
let infcx = selcx.infcx();
for predicate in env_predicates {
debug!("assemble_candidates_from_predicates: predicate={:?}", predicate);
if let &ty::PredicateKind::Projection(data) = predicate.kind() {
if let ty::PredicateAtom::Projection(data) = predicate.skip_binders() {
let data = ty::Binder::bind(data);
let same_def_id = data.projection_def_id() == obligation.predicate.item_def_id;
let is_match = same_def_id
@ -1221,11 +1224,12 @@ fn confirm_object_candidate<'cx, 'tcx>(
// select only those projections that are actually projecting an
// item with the correct name
let env_predicates = env_predicates.filter_map(|o| match o.predicate.kind() {
&ty::PredicateKind::Projection(data)
if data.projection_def_id() == obligation.predicate.item_def_id =>
let env_predicates = env_predicates.filter_map(|o| match o.predicate.skip_binders() {
ty::PredicateAtom::Projection(data)
if data.projection_ty.item_def_id == obligation.predicate.item_def_id =>
{
Some(data)
Some(ty::Binder::bind(data))
}
_ => None,
});

4
src/librustc_trait_selection/traits/query/type_op/prove_predicate.rs
View file

@ -15,10 +15,10 @@ impl<'tcx> super::QueryTypeOp<'tcx> for ProvePredicate<'tcx> {
// `&T`, accounts for about 60% percentage of the predicates
// we have to prove. No need to canonicalize and all that for
// such cases.
if let ty::PredicateKind::Trait(trait_ref, _) = key.value.predicate.kind() {
if let ty::PredicateAtom::Trait(trait_ref, _) = key.value.predicate.skip_binders() {
if let Some(sized_def_id) = tcx.lang_items().sized_trait() {
if trait_ref.def_id() == sized_def_id {
if trait_ref.skip_binder().self_ty().is_trivially_sized(tcx) {
if trait_ref.self_ty().is_trivially_sized(tcx) {
return Some(());
}
}

2
src/librustc_trait_selection/traits/select/confirmation.rs
View file

@ -532,7 +532,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
obligations.push(Obligation::new(
obligation.cause.clone(),
obligation.param_env,
ty::PredicateKind::ClosureKind(closure_def_id, substs, kind)
ty::PredicateAtom::ClosureKind(closure_def_id, substs, kind)
.to_predicate(self.tcx()),
));
}

41
src/librustc_trait_selection/traits/select/mod.rs
View file

@ -35,7 +35,9 @@ use rustc_middle::mir::interpret::ErrorHandled;
use rustc_middle::ty::fast_reject;
use rustc_middle::ty::relate::TypeRelation;
use rustc_middle::ty::subst::{GenericArgKind, Subst, SubstsRef};
use rustc_middle::ty::{self, ToPolyTraitRef, ToPredicate, Ty, TyCtxt, TypeFoldable};
use rustc_middle::ty::{
self, ToPolyTraitRef, ToPredicate, Ty, TyCtxt, TypeFoldable, WithConstness,
};
use rustc_span::symbol::sym;
use std::cell::{Cell, RefCell};
@ -406,14 +408,16 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
None => self.check_recursion_limit(&obligation, &obligation)?,
}
match obligation.predicate.kind() {
&ty::PredicateKind::Trait(t, _) => {
match obligation.predicate.skip_binders() {
ty::PredicateAtom::Trait(t, _) => {
let t = ty::Binder::bind(t);
debug_assert!(!t.has_escaping_bound_vars());
let obligation = obligation.with(t);
self.evaluate_trait_predicate_recursively(previous_stack, obligation)
}
&ty::PredicateKind::Subtype(p) => {
ty::PredicateAtom::Subtype(p) => {
let p = ty::Binder::bind(p);
// Does this code ever run?
match self.infcx.subtype_predicate(&obligation.cause, obligation.param_env, p) {
Some(Ok(InferOk { mut obligations, .. })) => {
@ -428,7 +432,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
}
&ty::PredicateKind::WellFormed(arg) => match wf::obligations(
ty::PredicateAtom::WellFormed(arg) => match wf::obligations(
self.infcx,
obligation.param_env,
obligation.cause.body_id,
@ -442,12 +446,12 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
None => Ok(EvaluatedToAmbig),
},
ty::PredicateKind::TypeOutlives(..) | ty::PredicateKind::RegionOutlives(..) => {
ty::PredicateAtom::TypeOutlives(..) | ty::PredicateAtom::RegionOutlives(..) => {
// We do not consider region relationships when evaluating trait matches.
Ok(EvaluatedToOkModuloRegions)
}
&ty::PredicateKind::ObjectSafe(trait_def_id) => {
ty::PredicateAtom::ObjectSafe(trait_def_id) => {
if self.tcx().is_object_safe(trait_def_id) {
Ok(EvaluatedToOk)
} else {
@ -455,7 +459,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
}
&ty::PredicateKind::Projection(data) => {
ty::PredicateAtom::Projection(data) => {
let data = ty::Binder::bind(data);
let project_obligation = obligation.with(data);
match project::poly_project_and_unify_type(self, &project_obligation) {
Ok(Some(mut subobligations)) => {
@ -476,7 +481,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
}
&ty::PredicateKind::ClosureKind(_, closure_substs, kind) => {
ty::PredicateAtom::ClosureKind(_, closure_substs, kind) => {
match self.infcx.closure_kind(closure_substs) {
Some(closure_kind) => {
if closure_kind.extends(kind) {
@ -489,7 +494,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
}
&ty::PredicateKind::ConstEvaluatable(def_id, substs) => {
ty::PredicateAtom::ConstEvaluatable(def_id, substs) => {
match self.tcx().const_eval_resolve(
obligation.param_env,
def_id,
@ -503,7 +508,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
}
ty::PredicateKind::ConstEquate(c1, c2) => {
ty::PredicateAtom::ConstEquate(c1, c2) => {
debug!("evaluate_predicate_recursively: equating consts c1={:?} c2={:?}", c1, c2);
let evaluate = |c: &'tcx ty::Const<'tcx>| {
@ -669,10 +674,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
// if the regions match exactly.
let cycle = stack.iter().skip(1).take_while(|s| s.depth >= cycle_depth);
let tcx = self.tcx();
let cycle = cycle.map(|stack| {
ty::PredicateKind::Trait(stack.obligation.predicate, hir::Constness::NotConst)
.to_predicate(tcx)
});
let cycle =
cycle.map(|stack| stack.obligation.predicate.without_const().to_predicate(tcx));
if self.coinductive_match(cycle) {
debug!("evaluate_stack({:?}) --> recursive, coinductive", stack.fresh_trait_ref);
Some(EvaluatedToOk)
@ -786,8 +789,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
}
fn coinductive_predicate(&self, predicate: ty::Predicate<'tcx>) -> bool {
let result = match predicate.kind() {
ty::PredicateKind::Trait(ref data, _) => self.tcx().trait_is_auto(data.def_id()),
let result = match predicate.skip_binders() {
ty::PredicateAtom::Trait(ref data, _) => self.tcx().trait_is_auto(data.def_id()),
_ => false,
};
debug!("coinductive_predicate({:?}) = {:?}", predicate, result);
@ -1295,8 +1298,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
};
let matching_bound = predicates.iter().find_map(|bound| {
if let ty::PredicateKind::Trait(bound, _) = bound.kind() {
let bound = bound.to_poly_trait_ref();
if let ty::PredicateAtom::Trait(pred, _) = bound.skip_binders() {
let bound = ty::Binder::bind(pred.trait_ref);
if self.infcx.probe(|_| {
self.match_projection(obligation, bound, placeholder_trait_predicate.trait_ref)
}) {

6
src/librustc_trait_selection/traits/util.rs
View file

@ -59,8 +59,8 @@ impl<'tcx> TraitAliasExpansionInfo<'tcx> {
);
}
pub fn trait_ref(&self) -> &ty::PolyTraitRef<'tcx> {
&self.top().0
pub fn trait_ref(&self) -> ty::PolyTraitRef<'tcx> {
self.top().0
}
pub fn top(&self) -> &(ty::PolyTraitRef<'tcx>, Span) {
@ -109,7 +109,7 @@ impl<'tcx> TraitAliasExpander<'tcx> {
// Don't recurse if this trait alias is already on the stack for the DFS search.
let anon_pred = anonymize_predicate(tcx, pred);
if item.path.iter().rev().skip(1).any(|(tr, _)| {
if item.path.iter().rev().skip(1).any(|&(tr, _)| {
anonymize_predicate(tcx, tr.without_const().to_predicate(tcx)) == anon_pred
}) {
return false;

68
src/librustc_trait_selection/traits/wf.rs
View file

@ -93,30 +93,29 @@ pub fn predicate_obligations<'a, 'tcx>(
) -> Vec<traits::PredicateObligation<'tcx>> {
let mut wf = WfPredicates { infcx, param_env, body_id, span, out: vec![], item: None };
// (*) ok to skip binders, because wf code is prepared for it
match predicate.kind() {
ty::PredicateKind::Trait(t, _) => {
wf.compute_trait_ref(&t.skip_binder().trait_ref, Elaborate::None); // (*)
// It's ok to skip the binder here because wf code is prepared for it
match predicate.skip_binders() {
ty::PredicateAtom::Trait(t, _) => {
wf.compute_trait_ref(&t.trait_ref, Elaborate::None);
}
ty::PredicateKind::RegionOutlives(..) => {}
ty::PredicateKind::TypeOutlives(t) => {
wf.compute(t.skip_binder().0.into());
ty::PredicateAtom::RegionOutlives(..) => {}
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(ty, _reg)) => {
wf.compute(ty.into());
}
ty::PredicateKind::Projection(t) => {
let t = t.skip_binder(); // (*)
ty::PredicateAtom::Projection(t) => {
wf.compute_projection(t.projection_ty);
wf.compute(t.ty.into());
}
&ty::PredicateKind::WellFormed(arg) => {
ty::PredicateAtom::WellFormed(arg) => {
wf.compute(arg);
}
ty::PredicateKind::ObjectSafe(_) => {}
ty::PredicateKind::ClosureKind(..) => {}
ty::PredicateKind::Subtype(data) => {
wf.compute(data.skip_binder().a.into()); // (*)
wf.compute(data.skip_binder().b.into()); // (*)
ty::PredicateAtom::ObjectSafe(_) => {}
ty::PredicateAtom::ClosureKind(..) => {}
ty::PredicateAtom::Subtype(ty::SubtypePredicate { a, b, a_is_expected: _ }) => {
wf.compute(a.into());
wf.compute(b.into());
}
&ty::PredicateKind::ConstEvaluatable(def, substs) => {
ty::PredicateAtom::ConstEvaluatable(def, substs) => {
let obligations = wf.nominal_obligations(def.did, substs);
wf.out.extend(obligations);
@ -124,7 +123,7 @@ pub fn predicate_obligations<'a, 'tcx>(
wf.compute(arg);
}
}
&ty::PredicateKind::ConstEquate(c1, c2) => {
ty::PredicateAtom::ConstEquate(c1, c2) => {
wf.compute(c1.into());
wf.compute(c2.into());
}
@ -176,7 +175,7 @@ fn extend_cause_with_original_assoc_item_obligation<'tcx>(
trait_ref: &ty::TraitRef<'tcx>,
item: Option<&hir::Item<'tcx>>,
cause: &mut traits::ObligationCause<'tcx>,
pred: &ty::Predicate<'_>,
pred: &ty::Predicate<'tcx>,
mut trait_assoc_items: impl Iterator<Item = &'tcx ty::AssocItem>,
) {
debug!(
@ -192,15 +191,16 @@ fn extend_cause_with_original_assoc_item_obligation<'tcx>(
hir::ImplItemKind::Const(ty, _) | hir::ImplItemKind::TyAlias(ty) => ty.span,
_ => impl_item_ref.span,
};
match pred.kind() {
ty::PredicateKind::Projection(proj) => {
// It is fine to skip the binder as we don't care about regions here.
match pred.skip_binders() {
ty::PredicateAtom::Projection(proj) => {
// The obligation comes not from the current `impl` nor the `trait` being implemented,
// but rather from a "second order" obligation, where an associated type has a
// projection coming from another associated type. See
// `src/test/ui/associated-types/point-at-type-on-obligation-failure.rs` and
// `traits-assoc-type-in-supertrait-bad.rs`.
let kind = &proj.ty().skip_binder().kind;
if let ty::Projection(projection_ty) = kind {
if let ty::Projection(projection_ty) = proj.ty.kind {
let trait_assoc_item = tcx.associated_item(projection_ty.item_def_id);
if let Some(impl_item_span) =
items.iter().find(|item| item.ident == trait_assoc_item.ident).map(fix_span)
@ -209,15 +209,13 @@ fn extend_cause_with_original_assoc_item_obligation<'tcx>(
}
}
}
ty::PredicateKind::Trait(pred, _) => {
ty::PredicateAtom::Trait(pred, _) => {
// An associated item obligation born out of the `trait` failed to be met. An example
// can be seen in `ui/associated-types/point-at-type-on-obligation-failure-2.rs`.
debug!("extended_cause_with_original_assoc_item_obligation trait proj {:?}", pred);
if let ty::Projection(ty::ProjectionTy { item_def_id, .. }) =
&pred.skip_binder().self_ty().kind
{
if let ty::Projection(ty::ProjectionTy { item_def_id, .. }) = pred.self_ty().kind {
if let Some(impl_item_span) = trait_assoc_items
.find(|i| i.def_id == *item_def_id)
.find(|i| i.def_id == item_def_id)
.and_then(|trait_assoc_item| {
items.iter().find(|i| i.ident == trait_assoc_item.ident).map(fix_span)
})
@ -316,7 +314,7 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
traits::Obligation::new(
new_cause,
param_env,
ty::PredicateKind::WellFormed(arg).to_predicate(tcx),
ty::PredicateAtom::WellFormed(arg).to_predicate(tcx),
)
}),
);
@ -373,7 +371,7 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
let obligations = self.nominal_obligations(def.did, substs);
self.out.extend(obligations);
let predicate = ty::PredicateKind::ConstEvaluatable(def, substs)
let predicate = ty::PredicateAtom::ConstEvaluatable(def, substs)
.to_predicate(self.tcx());
let cause = self.cause(traits::MiscObligation);
self.out.push(traits::Obligation::new(
@ -395,7 +393,7 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
self.out.push(traits::Obligation::new(
cause,
self.param_env,
ty::PredicateKind::WellFormed(resolved_constant.into())
ty::PredicateAtom::WellFormed(resolved_constant.into())
.to_predicate(self.tcx()),
));
}
@ -481,10 +479,8 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
self.out.push(traits::Obligation::new(
cause,
param_env,
ty::PredicateKind::TypeOutlives(ty::Binder::dummy(
ty::OutlivesPredicate(rty, r),
))
.to_predicate(self.tcx()),
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(rty, r))
.to_predicate(self.tcx()),
));
}
}
@ -574,7 +570,7 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
traits::Obligation::new(
cause.clone(),
param_env,
ty::PredicateKind::ObjectSafe(did).to_predicate(tcx),
ty::PredicateAtom::ObjectSafe(did).to_predicate(tcx),
)
}));
}
@ -600,7 +596,7 @@ impl<'a, 'tcx> WfPredicates<'a, 'tcx> {
self.out.push(traits::Obligation::new(
cause,
param_env,
ty::PredicateKind::WellFormed(ty.into()).to_predicate(self.tcx()),
ty::PredicateAtom::WellFormed(ty.into()).to_predicate(self.tcx()),
));
} else {
// Yes, resolved, proceed with the result.

115
src/librustc_traits/chalk/lowering.rs
View file

@ -78,10 +78,12 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::InEnvironment<chalk_ir::Goal<RustInterner<'
) -> chalk_ir::InEnvironment<chalk_ir::Goal<RustInterner<'tcx>>> {
let clauses = self.environment.into_iter().filter_map(|clause| match clause {
ChalkEnvironmentClause::Predicate(predicate) => {
match predicate.kind() {
ty::PredicateKind::Trait(predicate, _) => {
// FIXME(chalk): forall
match predicate.bound_atom(interner.tcx).skip_binder() {
ty::PredicateAtom::Trait(predicate, _) => {
let predicate = ty::Binder::bind(predicate);
let (predicate, binders, _named_regions) =
collect_bound_vars(interner, interner.tcx, predicate);
collect_bound_vars(interner, interner.tcx, &predicate);
Some(
chalk_ir::ProgramClauseData(chalk_ir::Binders::new(
@ -99,9 +101,10 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::InEnvironment<chalk_ir::Goal<RustInterner<'
.intern(interner),
)
}
ty::PredicateKind::RegionOutlives(predicate) => {
ty::PredicateAtom::RegionOutlives(predicate) => {
let predicate = ty::Binder::bind(predicate);
let (predicate, binders, _named_regions) =
collect_bound_vars(interner, interner.tcx, predicate);
collect_bound_vars(interner, interner.tcx, &predicate);
Some(
chalk_ir::ProgramClauseData(chalk_ir::Binders::new(
@ -123,10 +126,11 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::InEnvironment<chalk_ir::Goal<RustInterner<'
)
}
// FIXME(chalk): need to add TypeOutlives
ty::PredicateKind::TypeOutlives(_) => None,
ty::PredicateKind::Projection(predicate) => {
ty::PredicateAtom::TypeOutlives(_) => None,
ty::PredicateAtom::Projection(predicate) => {
let predicate = ty::Binder::bind(predicate);
let (predicate, binders, _named_regions) =
collect_bound_vars(interner, interner.tcx, predicate);
collect_bound_vars(interner, interner.tcx, &predicate);
Some(
chalk_ir::ProgramClauseData(chalk_ir::Binders::new(
@ -144,12 +148,12 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::InEnvironment<chalk_ir::Goal<RustInterner<'
.intern(interner),
)
}
ty::PredicateKind::WellFormed(..)
| ty::PredicateKind::ObjectSafe(..)
| ty::PredicateKind::ClosureKind(..)
| ty::PredicateKind::Subtype(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => {
ty::PredicateAtom::WellFormed(..)
| ty::PredicateAtom::ObjectSafe(..)
| ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::Subtype(..)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => {
bug!("unexpected predicate {}", predicate)
}
}
@ -181,11 +185,15 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::InEnvironment<chalk_ir::Goal<RustInterner<'
impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData<RustInterner<'tcx>>> for ty::Predicate<'tcx> {
fn lower_into(self, interner: &RustInterner<'tcx>) -> chalk_ir::GoalData<RustInterner<'tcx>> {
match self.kind() {
ty::PredicateKind::Trait(predicate, _) => predicate.lower_into(interner),
ty::PredicateKind::RegionOutlives(predicate) => {
// FIXME(chalk): forall
match self.bound_atom(interner.tcx).skip_binder() {
ty::PredicateAtom::Trait(predicate, _) => {
ty::Binder::bind(predicate).lower_into(interner)
}
ty::PredicateAtom::RegionOutlives(predicate) => {
let predicate = ty::Binder::bind(predicate);
let (predicate, binders, _named_regions) =
collect_bound_vars(interner, interner.tcx, predicate);
collect_bound_vars(interner, interner.tcx, &predicate);
chalk_ir::GoalData::Quantified(
chalk_ir::QuantifierKind::ForAll,
@ -202,20 +210,34 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData<RustInterner<'tcx>>> for ty::Predi
)
}
// FIXME(chalk): TypeOutlives
ty::PredicateKind::TypeOutlives(_predicate) => {
ty::PredicateAtom::TypeOutlives(_predicate) => {
chalk_ir::GoalData::All(chalk_ir::Goals::new(interner))
}
ty::PredicateKind::Projection(predicate) => predicate.lower_into(interner),
ty::PredicateKind::WellFormed(arg) => match arg.unpack() {
ty::PredicateAtom::Projection(predicate) => {
ty::Binder::bind(predicate).lower_into(interner)
}
ty::PredicateAtom::WellFormed(arg) => match arg.unpack() {
GenericArgKind::Type(ty) => match ty.kind {
// FIXME(chalk): In Chalk, a placeholder is WellFormed if it
// `FromEnv`. However, when we "lower" Params, we don't update
// the environment.
ty::Placeholder(..) => chalk_ir::GoalData::All(chalk_ir::Goals::new(interner)),
_ => chalk_ir::GoalData::DomainGoal(chalk_ir::DomainGoal::WellFormed(
chalk_ir::WellFormed::Ty(ty.lower_into(interner)),
)),
_ => {
let (ty, binders, _named_regions) =
collect_bound_vars(interner, interner.tcx, &ty::Binder::bind(ty));
chalk_ir::GoalData::Quantified(
chalk_ir::QuantifierKind::ForAll,
chalk_ir::Binders::new(
binders,
chalk_ir::GoalData::DomainGoal(chalk_ir::DomainGoal::WellFormed(
chalk_ir::WellFormed::Ty(ty.lower_into(interner)),
))
.intern(interner),
),
)
}
},
// FIXME(chalk): handle well formed consts
GenericArgKind::Const(..) => {
@ -224,18 +246,18 @@ impl<'tcx> LowerInto<'tcx, chalk_ir::GoalData<RustInterner<'tcx>>> for ty::Predi
GenericArgKind::Lifetime(lt) => bug!("unexpect well formed predicate: {:?}", lt),
},
ty::PredicateKind::ObjectSafe(t) => chalk_ir::GoalData::DomainGoal(
chalk_ir::DomainGoal::ObjectSafe(chalk_ir::TraitId(*t)),
ty::PredicateAtom::ObjectSafe(t) => chalk_ir::GoalData::DomainGoal(
chalk_ir::DomainGoal::ObjectSafe(chalk_ir::TraitId(t)),
),
// FIXME(chalk): other predicates
//
// We can defer this, but ultimately we'll want to express
// some of these in terms of chalk operations.
ty::PredicateKind::ClosureKind(..)
| ty::PredicateKind::Subtype(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => {
ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::Subtype(..)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => {
chalk_ir::GoalData::All(chalk_ir::Goals::new(interner))
}
}
@ -532,19 +554,22 @@ impl<'tcx> LowerInto<'tcx, Option<chalk_ir::QuantifiedWhereClause<RustInterner<'
self,
interner: &RustInterner<'tcx>,
) -> Option<chalk_ir::QuantifiedWhereClause<RustInterner<'tcx>>> {
match &self.kind() {
ty::PredicateKind::Trait(predicate, _) => {
// FIXME(chalk): forall
match self.bound_atom(interner.tcx).skip_binder() {
ty::PredicateAtom::Trait(predicate, _) => {
let predicate = ty::Binder::bind(predicate);
let (predicate, binders, _named_regions) =
collect_bound_vars(interner, interner.tcx, predicate);
collect_bound_vars(interner, interner.tcx, &predicate);
Some(chalk_ir::Binders::new(
binders,
chalk_ir::WhereClause::Implemented(predicate.trait_ref.lower_into(interner)),
))
}
ty::PredicateKind::RegionOutlives(predicate) => {
ty::PredicateAtom::RegionOutlives(predicate) => {
let predicate = ty::Binder::bind(predicate);
let (predicate, binders, _named_regions) =
collect_bound_vars(interner, interner.tcx, predicate);
collect_bound_vars(interner, interner.tcx, &predicate);
Some(chalk_ir::Binders::new(
binders,
@ -554,15 +579,15 @@ impl<'tcx> LowerInto<'tcx, Option<chalk_ir::QuantifiedWhereClause<RustInterner<'
}),
))
}
ty::PredicateKind::TypeOutlives(_predicate) => None,
ty::PredicateKind::Projection(_predicate) => None,
ty::PredicateKind::WellFormed(_ty) => None,
ty::PredicateAtom::TypeOutlives(_predicate) => None,
ty::PredicateAtom::Projection(_predicate) => None,
ty::PredicateAtom::WellFormed(_ty) => None,
ty::PredicateKind::ObjectSafe(..)
| ty::PredicateKind::ClosureKind(..)
| ty::PredicateKind::Subtype(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => bug!("unexpected predicate {}", &self),
ty::PredicateAtom::ObjectSafe(..)
| ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::Subtype(..)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => bug!("unexpected predicate {}", &self),
}
}
}
@ -632,7 +657,9 @@ crate fn collect_bound_vars<'a, 'tcx, T: TypeFoldable<'tcx>>(
}
(0..parameters.len()).for_each(|i| {
parameters.get(&(i as u32)).expect(&format!("Skipped bound var index `{:?}`.", i));
parameters
.get(&(i as u32))
.or_else(|| bug!("Skipped bound var index: ty={:?}, parameters={:?}", ty, parameters));
});
let binders = chalk_ir::VariableKinds::from(interner, parameters.into_iter().map(|(_, v)| v));

34
src/librustc_traits/implied_outlives_bounds.rs
View file

@ -95,29 +95,25 @@ fn compute_implied_outlives_bounds<'tcx>(
implied_bounds.extend(obligations.into_iter().flat_map(|obligation| {
assert!(!obligation.has_escaping_bound_vars());
match obligation.predicate.kind() {
ty::PredicateKind::Trait(..)
| ty::PredicateKind::Subtype(..)
| ty::PredicateKind::Projection(..)
| ty::PredicateKind::ClosureKind(..)
| ty::PredicateKind::ObjectSafe(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => vec![],
&ty::PredicateKind::ForAll(..) => vec![],
&ty::PredicateKind::Atom(atom) => match atom {
ty::PredicateAtom::Trait(..)
| ty::PredicateAtom::Subtype(..)
| ty::PredicateAtom::Projection(..)
| ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::ObjectSafe(..)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => vec![],
ty::PredicateAtom::WellFormed(arg) => {
wf_args.push(arg);
vec![]
}
&ty::PredicateKind::WellFormed(arg) => {
wf_args.push(arg);
vec![]
}
ty::PredicateKind::RegionOutlives(ref data) => match data.no_bound_vars() {
None => vec![],
Some(ty::OutlivesPredicate(r_a, r_b)) => {
ty::PredicateAtom::RegionOutlives(ty::OutlivesPredicate(r_a, r_b)) => {
vec![OutlivesBound::RegionSubRegion(r_b, r_a)]
}
},
ty::PredicateKind::TypeOutlives(ref data) => match data.no_bound_vars() {
None => vec![],
Some(ty::OutlivesPredicate(ty_a, r_b)) => {
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(ty_a, r_b)) => {
let ty_a = infcx.resolve_vars_if_possible(&ty_a);
let mut components = smallvec![];
tcx.push_outlives_components(ty_a, &mut components);

22
src/librustc_traits/normalize_erasing_regions.rs
View file

@ -39,16 +39,16 @@ fn normalize_generic_arg_after_erasing_regions<'tcx>(
})
}
fn not_outlives_predicate(p: &ty::Predicate<'_>) -> bool {
match p.kind() {
ty::PredicateKind::RegionOutlives(..) | ty::PredicateKind::TypeOutlives(..) => false,
ty::PredicateKind::Trait(..)
| ty::PredicateKind::Projection(..)
| ty::PredicateKind::WellFormed(..)
| ty::PredicateKind::ObjectSafe(..)
| ty::PredicateKind::ClosureKind(..)
| ty::PredicateKind::Subtype(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => true,
fn not_outlives_predicate(p: &ty::Predicate<'tcx>) -> bool {
match p.skip_binders() {
ty::PredicateAtom::RegionOutlives(..) | ty::PredicateAtom::TypeOutlives(..) => false,
ty::PredicateAtom::Trait(..)
| ty::PredicateAtom::Projection(..)
| ty::PredicateAtom::WellFormed(..)
| ty::PredicateAtom::ObjectSafe(..)
| ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::Subtype(..)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => true,
}
}

4
src/librustc_traits/type_op.rs
View file

@ -140,7 +140,7 @@ impl AscribeUserTypeCx<'me, 'tcx> {
self.relate(self_ty, Variance::Invariant, impl_self_ty)?;
self.prove_predicate(
ty::PredicateKind::WellFormed(impl_self_ty.into()).to_predicate(self.tcx()),
ty::PredicateAtom::WellFormed(impl_self_ty.into()).to_predicate(self.tcx()),
);
}
@ -155,7 +155,7 @@ impl AscribeUserTypeCx<'me, 'tcx> {
// them? This would only be relevant if some input
// type were ill-formed but did not appear in `ty`,
// which...could happen with normalization...
self.prove_predicate(ty::PredicateKind::WellFormed(ty.into()).to_predicate(self.tcx()));
self.prove_predicate(ty::PredicateAtom::WellFormed(ty.into()).to_predicate(self.tcx()));
Ok(())
}
}

31
src/librustc_ty/ty.rs
View file

@ -392,23 +392,23 @@ fn associated_type_projection_predicates(
let predicates = item_predicates.filter_map(|obligation| {
let pred = obligation.predicate;
match pred.kind() {
ty::PredicateKind::Trait(tr, _) => {
if let ty::Projection(p) = tr.skip_binder().self_ty().kind {
match pred.skip_binders() {
ty::PredicateAtom::Trait(tr, _) => {
if let ty::Projection(p) = tr.self_ty().kind {
if p == assoc_item_ty {
return Some(pred);
}
}
}
ty::PredicateKind::Projection(proj) => {
if let ty::Projection(p) = proj.skip_binder().projection_ty.self_ty().kind {
ty::PredicateAtom::Projection(proj) => {
if let ty::Projection(p) = proj.projection_ty.self_ty().kind {
if p == assoc_item_ty {
return Some(pred);
}
}
}
ty::PredicateKind::TypeOutlives(outlives) => {
if let ty::Projection(p) = outlives.skip_binder().0.kind {
ty::PredicateAtom::TypeOutlives(outlives) => {
if let ty::Projection(p) = outlives.0.kind {
if p == assoc_item_ty {
return Some(pred);
}
@ -443,25 +443,24 @@ fn opaque_type_projection_predicates(
let filtered_predicates = predicates.filter_map(|obligation| {
let pred = obligation.predicate;
match pred.kind() {
ty::PredicateKind::Trait(tr, _) => {
if let ty::Opaque(opaque_def_id, opaque_substs) = tr.skip_binder().self_ty().kind {
match pred.skip_binders() {
ty::PredicateAtom::Trait(tr, _) => {
if let ty::Opaque(opaque_def_id, opaque_substs) = tr.self_ty().kind {
if opaque_def_id == def_id && opaque_substs == substs {
return Some(pred);
}
}
}
ty::PredicateKind::Projection(proj) => {
if let ty::Opaque(opaque_def_id, opaque_substs) =
proj.skip_binder().projection_ty.self_ty().kind
ty::PredicateAtom::Projection(proj) => {
if let ty::Opaque(opaque_def_id, opaque_substs) = proj.projection_ty.self_ty().kind
{
if opaque_def_id == def_id && opaque_substs == substs {
return Some(pred);
}
}
}
ty::PredicateKind::TypeOutlives(outlives) => {
if let ty::Opaque(opaque_def_id, opaque_substs) = outlives.skip_binder().0.kind {
ty::PredicateAtom::TypeOutlives(outlives) => {
if let ty::Opaque(opaque_def_id, opaque_substs) = outlives.0.kind {
if opaque_def_id == def_id && opaque_substs == substs {
return Some(pred);
}
@ -471,7 +470,7 @@ fn opaque_type_projection_predicates(
}
}
// These can come from elaborating other predicates
ty::PredicateKind::RegionOutlives(_) => return None,
ty::PredicateAtom::RegionOutlives(_) => return None,
_ => {}
}
tcx.sess.delay_span_bug(

9
src/librustc_typeck/astconv.rs
View file

@ -1705,8 +1705,10 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
"conv_object_ty_poly_trait_ref: observing object predicate `{:?}`",
obligation.predicate
);
match obligation.predicate.kind() {
ty::PredicateKind::Trait(pred, _) => {
match obligation.predicate.skip_binders() {
ty::PredicateAtom::Trait(pred, _) => {
let pred = ty::Binder::bind(pred);
associated_types.entry(span).or_default().extend(
tcx.associated_items(pred.def_id())
.in_definition_order()
@ -1714,7 +1716,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
.map(|item| item.def_id),
);
}
&ty::PredicateKind::Projection(pred) => {
ty::PredicateAtom::Projection(pred) => {
let pred = ty::Binder::bind(pred);
// A `Self` within the original bound will be substituted with a
// `trait_object_dummy_self`, so check for that.
let references_self =

17
src/librustc_typeck/check/closure.rs
View file

@ -206,11 +206,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
obligation.predicate
);
if let &ty::PredicateKind::Projection(proj_predicate) = obligation.predicate.kind()
if let ty::PredicateAtom::Projection(proj_predicate) =
obligation.predicate.skip_binders()
{
// Given a Projection predicate, we can potentially infer
// the complete signature.
self.deduce_sig_from_projection(Some(obligation.cause.span), proj_predicate)
self.deduce_sig_from_projection(
Some(obligation.cause.span),
ty::Binder::bind(proj_predicate),
)
} else {
None
}
@ -627,8 +631,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
// where R is the return type we are expecting. This type `T`
// will be our output.
let output_ty = self.obligations_for_self_ty(ret_vid).find_map(|(_, obligation)| {
if let &ty::PredicateKind::Projection(proj_predicate) = obligation.predicate.kind() {
self.deduce_future_output_from_projection(obligation.cause.span, proj_predicate)
if let ty::PredicateAtom::Projection(proj_predicate) =
obligation.predicate.skip_binders()
{
self.deduce_future_output_from_projection(
obligation.cause.span,
ty::Binder::bind(proj_predicate),
)
} else {
None
}

8
src/librustc_typeck/check/coercion.rs
View file

@ -582,18 +582,18 @@ impl<'f, 'tcx> Coerce<'f, 'tcx> {
while !queue.is_empty() {
let obligation = queue.remove(0);
debug!("coerce_unsized resolve step: {:?}", obligation);
let trait_pred = match obligation.predicate.kind() {
&ty::PredicateKind::Trait(trait_pred, _)
let trait_pred = match obligation.predicate.skip_binders() {
ty::PredicateAtom::Trait(trait_pred, _)
if traits.contains(&trait_pred.def_id()) =>
{
if unsize_did == trait_pred.def_id() {
let unsize_ty = trait_pred.skip_binder().trait_ref.substs[1].expect_ty();
let unsize_ty = trait_pred.trait_ref.substs[1].expect_ty();
if let ty::Tuple(..) = unsize_ty.kind {
debug!("coerce_unsized: found unsized tuple coercion");
has_unsized_tuple_coercion = true;
}
}
trait_pred
ty::Binder::bind(trait_pred)
}
_ => {
coercion.obligations.push(obligation);

10
src/librustc_typeck/check/dropck.rs
View file

@ -226,12 +226,12 @@ fn ensure_drop_predicates_are_implied_by_item_defn<'tcx>(
// could be extended easily also to the other `Predicate`.
let predicate_matches_closure = |p: Predicate<'tcx>| {
let mut relator: SimpleEqRelation<'tcx> = SimpleEqRelation::new(tcx, self_param_env);
match (predicate.kind(), p.kind()) {
(&ty::PredicateKind::Trait(a, _), &ty::PredicateKind::Trait(b, _)) => {
relator.relate(a, b).is_ok()
match (predicate.skip_binders(), p.skip_binders()) {
(ty::PredicateAtom::Trait(a, _), ty::PredicateAtom::Trait(b, _)) => {
relator.relate(ty::Binder::bind(a), ty::Binder::bind(b)).is_ok()
}
(&ty::PredicateKind::Projection(a), &ty::PredicateKind::Projection(b)) => {
relator.relate(a, b).is_ok()
(ty::PredicateAtom::Projection(a), ty::PredicateAtom::Projection(b)) => {
relator.relate(ty::Binder::bind(a), ty::Binder::bind(b)).is_ok()
}
_ => predicate == p,
}

11
src/librustc_typeck/check/method/confirm.rs
View file

@ -447,21 +447,24 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
};
traits::elaborate_predicates(self.tcx, predicates.predicates.iter().copied())
.filter_map(|obligation| match obligation.predicate.kind() {
ty::PredicateKind::Trait(trait_pred, _) if trait_pred.def_id() == sized_def_id => {
// We don't care about regions here.
.filter_map(|obligation| match obligation.predicate.skip_binders() {
ty::PredicateAtom::Trait(trait_pred, _) if trait_pred.def_id() == sized_def_id => {
let span = predicates
.predicates
.iter()
.zip(predicates.spans.iter())
.find_map(
|(p, span)| if *p == obligation.predicate { Some(*span) } else { None },
|(p, span)| {
if *p == obligation.predicate { Some(*span) } else { None }
},
)
.unwrap_or(rustc_span::DUMMY_SP);
Some((trait_pred, span))
}
_ => None,
})
.find_map(|(trait_pred, span)| match trait_pred.skip_binder().self_ty().kind {
.find_map(|(trait_pred, span)| match trait_pred.self_ty().kind {
ty::Dynamic(..) => Some(span),
_ => None,
})

2
src/librustc_typeck/check/method/mod.rs
View file

@ -399,7 +399,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
obligations.push(traits::Obligation::new(
cause,
self.param_env,
ty::PredicateKind::WellFormed(method_ty.into()).to_predicate(tcx),
ty::PredicateAtom::WellFormed(method_ty.into()).to_predicate(tcx),
));
let callee = MethodCallee { def_id, substs: trait_ref.substs, sig: fn_sig };

41
src/librustc_typeck/check/method/probe.rs
View file

@ -798,25 +798,28 @@ impl<'a, 'tcx> ProbeContext<'a, 'tcx> {
// FIXME: do we want to commit to this behavior for param bounds?
debug!("assemble_inherent_candidates_from_param(param_ty={:?})", param_ty);
let bounds = self.param_env.caller_bounds().iter().filter_map(|predicate| match predicate
.kind()
{
ty::PredicateKind::Trait(ref trait_predicate, _) => {
match trait_predicate.skip_binder().trait_ref.self_ty().kind {
ty::Param(ref p) if *p == param_ty => Some(trait_predicate.to_poly_trait_ref()),
_ => None,
}
}
ty::PredicateKind::Subtype(..)
| ty::PredicateKind::Projection(..)
| ty::PredicateKind::RegionOutlives(..)
| ty::PredicateKind::WellFormed(..)
| ty::PredicateKind::ObjectSafe(..)
| ty::PredicateKind::ClosureKind(..)
| ty::PredicateKind::TypeOutlives(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => None,
});
let bounds =
self.param_env.caller_bounds().iter().map(ty::Predicate::skip_binders).filter_map(
|predicate| match predicate {
ty::PredicateAtom::Trait(trait_predicate, _) => {
match trait_predicate.trait_ref.self_ty().kind {
ty::Param(ref p) if *p == param_ty => {
Some(ty::Binder::bind(trait_predicate.trait_ref))
}
_ => None,
}
}
ty::PredicateAtom::Subtype(..)
| ty::PredicateAtom::Projection(..)
| ty::PredicateAtom::RegionOutlives(..)
| ty::PredicateAtom::WellFormed(..)
| ty::PredicateAtom::ObjectSafe(..)
| ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::TypeOutlives(..)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => None,
},
);
self.elaborate_bounds(bounds, |this, poly_trait_ref, item| {
let trait_ref = this.erase_late_bound_regions(&poly_trait_ref);

34
src/librustc_typeck/check/method/suggest.rs
View file

@ -570,12 +570,14 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
};
let mut type_params = FxHashMap::default();
let mut bound_spans = vec![];
let mut collect_type_param_suggestions =
|self_ty: Ty<'_>, parent_pred: &ty::Predicate<'_>, obligation: &str| {
if let (ty::Param(_), ty::PredicateKind::Trait(p, _)) =
(&self_ty.kind, parent_pred.kind())
|self_ty: Ty<'tcx>, parent_pred: &ty::Predicate<'tcx>, obligation: &str| {
// We don't care about regions here, so it's fine to skip the binder here.
if let (ty::Param(_), ty::PredicateAtom::Trait(p, _)) =
(&self_ty.kind, parent_pred.skip_binders())
{
if let ty::Adt(def, _) = p.skip_binder().trait_ref.self_ty().kind {
if let ty::Adt(def, _) = p.trait_ref.self_ty().kind {
let node = def.did.as_local().map(|def_id| {
self.tcx.hir().get(self.tcx.hir().as_local_hir_id(def_id))
});
@ -625,8 +627,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
}
};
let mut format_pred = |pred: ty::Predicate<'tcx>| {
match pred.kind() {
ty::PredicateKind::Projection(pred) => {
match pred.skip_binders() {
ty::PredicateAtom::Projection(pred) => {
let pred = ty::Binder::bind(pred);
// `<Foo as Iterator>::Item = String`.
let trait_ref =
pred.skip_binder().projection_ty.trait_ref(self.tcx);
@ -644,7 +647,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
bound_span_label(trait_ref.self_ty(), &obligation, &quiet);
Some((obligation, trait_ref.self_ty()))
}
ty::PredicateKind::Trait(poly_trait_ref, _) => {
ty::PredicateAtom::Trait(poly_trait_ref, _) => {
let poly_trait_ref = ty::Binder::bind(poly_trait_ref);
let p = poly_trait_ref.skip_binder().trait_ref;
let self_ty = p.self_ty();
let path = p.print_only_trait_path();
@ -950,12 +954,16 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
// this isn't perfect (that is, there are cases when
// implementing a trait would be legal but is rejected
// here).
unsatisfied_predicates.iter().all(|(p, _)| match p.kind() {
// Hide traits if they are present in predicates as they can be fixed without
// having to implement them.
ty::PredicateKind::Trait(t, _) => t.def_id() == info.def_id,
ty::PredicateKind::Projection(p) => p.item_def_id() == info.def_id,
_ => false,
unsatisfied_predicates.iter().all(|(p, _)| {
match p.skip_binders() {
// Hide traits if they are present in predicates as they can be fixed without
// having to implement them.
ty::PredicateAtom::Trait(t, _) => t.def_id() == info.def_id,
ty::PredicateAtom::Projection(p) => {
p.projection_ty.item_def_id == info.def_id
}
_ => false,
}
}) && (type_is_local || info.def_id.is_local())
&& self
.associated_item(info.def_id, item_name, Namespace::ValueNS)

111
src/librustc_typeck/check/mod.rs
View file

@ -2392,26 +2392,26 @@ fn missing_items_err(
}
/// Resugar `ty::GenericPredicates` in a way suitable to be used in structured suggestions.
fn bounds_from_generic_predicates(
tcx: TyCtxt<'_>,
predicates: ty::GenericPredicates<'_>,
fn bounds_from_generic_predicates<'tcx>(
tcx: TyCtxt<'tcx>,
predicates: ty::GenericPredicates<'tcx>,
) -> (String, String) {
let mut types: FxHashMap<Ty<'_>, Vec<DefId>> = FxHashMap::default();
let mut types: FxHashMap<Ty<'tcx>, Vec<DefId>> = FxHashMap::default();
let mut projections = vec![];
for (predicate, _) in predicates.predicates {
debug!("predicate {:?}", predicate);
match predicate.kind() {
ty::PredicateKind::Trait(trait_predicate, _) => {
let entry = types.entry(trait_predicate.skip_binder().self_ty()).or_default();
let def_id = trait_predicate.skip_binder().def_id();
match predicate.skip_binders() {
ty::PredicateAtom::Trait(trait_predicate, _) => {
let entry = types.entry(trait_predicate.self_ty()).or_default();
let def_id = trait_predicate.def_id();
if Some(def_id) != tcx.lang_items().sized_trait() {
// Type params are `Sized` by default, do not add that restriction to the list
// if it is a positive requirement.
entry.push(trait_predicate.skip_binder().def_id());
entry.push(trait_predicate.def_id());
}
}
ty::PredicateKind::Projection(projection_pred) => {
projections.push(projection_pred);
ty::PredicateAtom::Projection(projection_pred) => {
projections.push(ty::Binder::bind(projection_pred));
}
_ => {}
}
@ -2456,11 +2456,11 @@ fn bounds_from_generic_predicates(
}
/// Return placeholder code for the given function.
fn fn_sig_suggestion(
tcx: TyCtxt<'_>,
sig: ty::FnSig<'_>,
fn fn_sig_suggestion<'tcx>(
tcx: TyCtxt<'tcx>,
sig: ty::FnSig<'tcx>,
ident: Ident,
predicates: ty::GenericPredicates<'_>,
predicates: ty::GenericPredicates<'tcx>,
assoc: &ty::AssocItem,
) -> String {
let args = sig
@ -2938,10 +2938,8 @@ impl<'a, 'tcx> AstConv<'tcx> for FnCtxt<'a, 'tcx> {
parent: None,
predicates: tcx.arena.alloc_from_iter(
self.param_env.caller_bounds().iter().filter_map(|predicate| {
match predicate.kind() {
ty::PredicateKind::Trait(ref data, _)
if data.skip_binder().self_ty().is_param(index) =>
{
match predicate.skip_binders() {
ty::PredicateAtom::Trait(data, _) if data.self_ty().is_param(index) => {
// HACK(eddyb) should get the original `Span`.
let span = tcx.def_span(def_id);
Some((predicate, span))
@ -3612,7 +3610,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
self.register_predicate(traits::Obligation::new(
cause,
self.param_env,
ty::PredicateKind::WellFormed(arg).to_predicate(self.tcx),
ty::PredicateAtom::WellFormed(arg).to_predicate(self.tcx),
));
}
@ -3893,29 +3891,31 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
.borrow()
.pending_obligations()
.into_iter()
.filter_map(move |obligation| match obligation.predicate.kind() {
ty::PredicateKind::Projection(ref data) => {
Some((data.to_poly_trait_ref(self.tcx), obligation))
.filter_map(move |obligation| {
match obligation.predicate.skip_binders() {
ty::PredicateAtom::Projection(data) => {
Some((ty::Binder::bind(data).to_poly_trait_ref(self.tcx), obligation))
}
ty::PredicateAtom::Trait(data, _) => {
Some((ty::Binder::bind(data).to_poly_trait_ref(), obligation))
}
ty::PredicateAtom::Subtype(..) => None,
ty::PredicateAtom::RegionOutlives(..) => None,
ty::PredicateAtom::TypeOutlives(..) => None,
ty::PredicateAtom::WellFormed(..) => None,
ty::PredicateAtom::ObjectSafe(..) => None,
ty::PredicateAtom::ConstEvaluatable(..) => None,
ty::PredicateAtom::ConstEquate(..) => None,
// N.B., this predicate is created by breaking down a
// `ClosureType: FnFoo()` predicate, where
// `ClosureType` represents some `Closure`. It can't
// possibly be referring to the current closure,
// because we haven't produced the `Closure` for
// this closure yet; this is exactly why the other
// code is looking for a self type of a unresolved
// inference variable.
ty::PredicateAtom::ClosureKind(..) => None,
}
ty::PredicateKind::Trait(ref data, _) => {
Some((data.to_poly_trait_ref(), obligation))
}
ty::PredicateKind::Subtype(..) => None,
ty::PredicateKind::RegionOutlives(..) => None,
ty::PredicateKind::TypeOutlives(..) => None,
ty::PredicateKind::WellFormed(..) => None,
ty::PredicateKind::ObjectSafe(..) => None,
ty::PredicateKind::ConstEvaluatable(..) => None,
ty::PredicateKind::ConstEquate(..) => None,
// N.B., this predicate is created by breaking down a
// `ClosureType: FnFoo()` predicate, where
// `ClosureType` represents some `Closure`. It can't
// possibly be referring to the current closure,
// because we haven't produced the `Closure` for
// this closure yet; this is exactly why the other
// code is looking for a self type of a unresolved
// inference variable.
ty::PredicateKind::ClosureKind(..) => None,
})
.filter(move |(tr, _)| self.self_type_matches_expected_vid(*tr, ty_var_root))
}
@ -4225,7 +4225,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
/// the corresponding argument's expression span instead of the `fn` call path span.
fn point_at_arg_instead_of_call_if_possible(
&self,
errors: &mut Vec<traits::FulfillmentError<'_>>,
errors: &mut Vec<traits::FulfillmentError<'tcx>>,
final_arg_types: &[(usize, Ty<'tcx>, Ty<'tcx>)],
call_sp: Span,
args: &'tcx [hir::Expr<'tcx>],
@ -4244,7 +4244,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
continue;
}
if let ty::PredicateKind::Trait(predicate, _) = error.obligation.predicate.kind() {
if let ty::PredicateAtom::Trait(predicate, _) =
error.obligation.predicate.skip_binders()
{
// Collect the argument position for all arguments that could have caused this
// `FulfillmentError`.
let mut referenced_in = final_arg_types
@ -4255,7 +4257,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
let ty = self.resolve_vars_if_possible(&ty);
// We walk the argument type because the argument's type could have
// been `Option<T>`, but the `FulfillmentError` references `T`.
if ty.walk().any(|arg| arg == predicate.skip_binder().self_ty().into()) {
if ty.walk().any(|arg| arg == predicate.self_ty().into()) {
Some(i)
} else {
None
@ -4284,15 +4286,15 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
/// instead of the `fn` call path span.
fn point_at_type_arg_instead_of_call_if_possible(
&self,
errors: &mut Vec<traits::FulfillmentError<'_>>,
errors: &mut Vec<traits::FulfillmentError<'tcx>>,
call_expr: &'tcx hir::Expr<'tcx>,
) {
if let hir::ExprKind::Call(path, _) = &call_expr.kind {
if let hir::ExprKind::Path(qpath) = &path.kind {
if let hir::QPath::Resolved(_, path) = &qpath {
for error in errors {
if let ty::PredicateKind::Trait(predicate, _) =
error.obligation.predicate.kind()
if let ty::PredicateAtom::Trait(predicate, _) =
error.obligation.predicate.skip_binders()
{
// If any of the type arguments in this path segment caused the
// `FullfillmentError`, point at its span (#61860).
@ -4313,7 +4315,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
} else {
let ty = AstConv::ast_ty_to_ty(self, hir_ty);
let ty = self.resolve_vars_if_possible(&ty);
if ty == predicate.skip_binder().self_ty() {
if ty == predicate.self_ty() {
error.obligation.cause.make_mut().span = hir_ty.span;
}
}
@ -5365,12 +5367,11 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
item_def_id,
};
let predicate =
ty::PredicateKind::Projection(ty::Binder::bind(ty::ProjectionPredicate {
projection_ty,
ty: expected,
}))
.to_predicate(self.tcx);
let predicate = ty::PredicateAtom::Projection(ty::ProjectionPredicate {
projection_ty,
ty: expected,
})
.potentially_quantified(self.tcx, ty::PredicateKind::ForAll);
let obligation = traits::Obligation::new(self.misc(sp), self.param_env, predicate);
debug!("suggest_missing_await: trying obligation {:?}", obligation);

2
src/librustc_typeck/check/wfcheck.rs
View file

@ -429,7 +429,7 @@ fn check_type_defn<'tcx, F>(
fcx.register_predicate(traits::Obligation::new(
cause,
fcx.param_env,
ty::PredicateKind::ConstEvaluatable(
ty::PredicateAtom::ConstEvaluatable(
ty::WithOptConstParam::unknown(discr_def_id.to_def_id()),
discr_substs,
)

25
src/librustc_typeck/collect.rs
View file

@ -552,10 +552,8 @@ fn type_param_predicates(
let extra_predicates = extend.into_iter().chain(
icx.type_parameter_bounds_in_generics(ast_generics, param_id, ty, OnlySelfBounds(true))
.into_iter()
.filter(|(predicate, _)| match predicate.kind() {
ty::PredicateKind::Trait(ref data, _) => {
data.skip_binder().self_ty().is_param(index)
}
.filter(|(predicate, _)| match predicate.skip_binders() {
ty::PredicateAtom::Trait(data, _) => data.self_ty().is_param(index),
_ => false,
}),
);
@ -1006,7 +1004,7 @@ fn super_predicates_of(tcx: TyCtxt<'_>, trait_def_id: DefId) -> ty::GenericPredi
// which will, in turn, reach indirect supertraits.
for &(pred, span) in superbounds {
debug!("superbound: {:?}", pred);
if let ty::PredicateKind::Trait(bound, _) = pred.kind() {
if let ty::PredicateAtom::Trait(bound, _) = pred.skip_binders() {
tcx.at(span).super_predicates_of(bound.def_id());
}
}
@ -1932,8 +1930,8 @@ fn explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicat
let re_root_empty = tcx.lifetimes.re_root_empty;
let predicate = ty::OutlivesPredicate(ty, re_root_empty);
predicates.push((
ty::PredicateKind::TypeOutlives(ty::Binder::bind(predicate))
.to_predicate(tcx),
ty::PredicateAtom::TypeOutlives(predicate)
.potentially_quantified(tcx, ty::PredicateKind::ForAll),
span,
));
}
@ -1961,9 +1959,9 @@ fn explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicat
&hir::GenericBound::Outlives(ref lifetime) => {
let region = AstConv::ast_region_to_region(&icx, lifetime, None);
let pred = ty::Binder::bind(ty::OutlivesPredicate(ty, region));
predicates.push((
ty::PredicateKind::TypeOutlives(pred).to_predicate(tcx),
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(ty, region))
.potentially_quantified(tcx, ty::PredicateKind::ForAll),
lifetime.span,
))
}
@ -1980,9 +1978,9 @@ fn explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericPredicat
}
_ => bug!(),
};
let pred = ty::Binder::bind(ty::OutlivesPredicate(r1, r2));
let pred = ty::PredicateAtom::RegionOutlives(ty::OutlivesPredicate(r1, r2));
(ty::PredicateKind::RegionOutlives(pred).to_predicate(icx.tcx), span)
(pred.potentially_quantified(icx.tcx, ty::PredicateKind::ForAll), span)
}))
}
@ -2110,8 +2108,9 @@ fn predicates_from_bound<'tcx>(
}
hir::GenericBound::Outlives(ref lifetime) => {
let region = astconv.ast_region_to_region(lifetime, None);
let pred = ty::Binder::bind(ty::OutlivesPredicate(param_ty, region));
vec![(ty::PredicateKind::TypeOutlives(pred).to_predicate(astconv.tcx()), lifetime.span)]
let pred = ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(param_ty, region))
.potentially_quantified(astconv.tcx(), ty::PredicateKind::ForAll);
vec![(pred, lifetime.span)]
}
}
}

8
src/librustc_typeck/constrained_generic_params.rs
View file

@ -180,11 +180,9 @@ pub fn setup_constraining_predicates<'tcx>(
changed = false;
for j in i..predicates.len() {
if let ty::PredicateKind::Projection(ref poly_projection) = predicates[j].0.kind() {
// Note that we can skip binder here because the impl
// trait ref never contains any late-bound regions.
let projection = poly_projection.skip_binder();
// Note that we don't have to care about binders here,
// as the impl trait ref never contains any late-bound regions.
if let ty::PredicateAtom::Projection(projection) = predicates[j].0.skip_binders() {
// Special case: watch out for some kind of sneaky attempt
// to project out an associated type defined by this very
// trait.

34
src/librustc_typeck/impl_wf_check/min_specialization.rs
View file

@ -198,9 +198,9 @@ fn unconstrained_parent_impl_substs<'tcx>(
// the functions in `cgp` add the constrained parameters to a list of
// unconstrained parameters.
for (predicate, _) in impl_generic_predicates.predicates.iter() {
if let ty::PredicateKind::Projection(proj) = predicate.kind() {
let projection_ty = proj.skip_binder().projection_ty;
let projected_ty = proj.skip_binder().ty;
if let ty::PredicateAtom::Projection(proj) = predicate.skip_binders() {
let projection_ty = proj.projection_ty;
let projected_ty = proj.ty;
let unbound_trait_ref = projection_ty.trait_ref(tcx);
if Some(unbound_trait_ref) == impl_trait_ref {
@ -359,13 +359,13 @@ fn check_predicates<'tcx>(
fn check_specialization_on<'tcx>(tcx: TyCtxt<'tcx>, predicate: ty::Predicate<'tcx>, span: Span) {
debug!("can_specialize_on(predicate = {:?})", predicate);
match predicate.kind() {
match predicate.skip_binders() {
// Global predicates are either always true or always false, so we
// are fine to specialize on.
_ if predicate.is_global() => (),
// We allow specializing on explicitly marked traits with no associated
// items.
ty::PredicateKind::Trait(pred, hir::Constness::NotConst) => {
ty::PredicateAtom::Trait(pred, hir::Constness::NotConst) => {
if !matches!(
trait_predicate_kind(tcx, predicate),
Some(TraitSpecializationKind::Marker)
@ -392,19 +392,19 @@ fn trait_predicate_kind<'tcx>(
tcx: TyCtxt<'tcx>,
predicate: ty::Predicate<'tcx>,
) -> Option<TraitSpecializationKind> {
match predicate.kind() {
ty::PredicateKind::Trait(pred, hir::Constness::NotConst) => {
match predicate.skip_binders() {
ty::PredicateAtom::Trait(pred, hir::Constness::NotConst) => {
Some(tcx.trait_def(pred.def_id()).specialization_kind)
}
ty::PredicateKind::Trait(_, hir::Constness::Const)
| ty::PredicateKind::RegionOutlives(_)
| ty::PredicateKind::TypeOutlives(_)
| ty::PredicateKind::Projection(_)
| ty::PredicateKind::WellFormed(_)
| ty::PredicateKind::Subtype(_)
| ty::PredicateKind::ObjectSafe(_)
| ty::PredicateKind::ClosureKind(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => None,
ty::PredicateAtom::Trait(_, hir::Constness::Const)
| ty::PredicateAtom::RegionOutlives(_)
| ty::PredicateAtom::TypeOutlives(_)
| ty::PredicateAtom::Projection(_)
| ty::PredicateAtom::WellFormed(_)
| ty::PredicateAtom::Subtype(_)
| ty::PredicateAtom::ObjectSafe(_)
| ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => None,
}
}

24
src/librustc_typeck/outlives/explicit.rs
View file

@ -29,9 +29,8 @@ impl<'tcx> ExplicitPredicatesMap<'tcx> {
// process predicates and convert to `RequiredPredicates` entry, see below
for &(predicate, span) in predicates.predicates {
match predicate.kind() {
ty::PredicateKind::TypeOutlives(predicate) => {
let OutlivesPredicate(ref ty, ref reg) = predicate.skip_binder();
match predicate.skip_binders() {
ty::PredicateAtom::TypeOutlives(OutlivesPredicate(ref ty, ref reg)) => {
insert_outlives_predicate(
tcx,
(*ty).into(),
@ -41,8 +40,7 @@ impl<'tcx> ExplicitPredicatesMap<'tcx> {
)
}
ty::PredicateKind::RegionOutlives(predicate) => {
let OutlivesPredicate(ref reg1, ref reg2) = predicate.skip_binder();
ty::PredicateAtom::RegionOutlives(OutlivesPredicate(ref reg1, ref reg2)) => {
insert_outlives_predicate(
tcx,
(*reg1).into(),
@ -52,14 +50,14 @@ impl<'tcx> ExplicitPredicatesMap<'tcx> {
)
}
ty::PredicateKind::Trait(..)
| ty::PredicateKind::Projection(..)
| ty::PredicateKind::WellFormed(..)
| ty::PredicateKind::ObjectSafe(..)
| ty::PredicateKind::ClosureKind(..)
| ty::PredicateKind::Subtype(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => (),
ty::PredicateAtom::Trait(..)
| ty::PredicateAtom::Projection(..)
| ty::PredicateAtom::WellFormed(..)
| ty::PredicateAtom::ObjectSafe(..)
| ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::Subtype(..)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => (),
}
}

22
src/librustc_typeck/outlives/mod.rs
View file

@ -3,7 +3,7 @@ use rustc_hir as hir;
use rustc_hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
use rustc_middle::ty::query::Providers;
use rustc_middle::ty::subst::GenericArgKind;
use rustc_middle::ty::{self, CratePredicatesMap, ToPredicate, TyCtxt};
use rustc_middle::ty::{self, CratePredicatesMap, TyCtxt};
use rustc_span::symbol::sym;
use rustc_span::Span;
@ -31,8 +31,12 @@ fn inferred_outlives_of(tcx: TyCtxt<'_>, item_def_id: DefId) -> &[(ty::Predicate
let mut pred: Vec<String> = predicates
.iter()
.map(|(out_pred, _)| match out_pred.kind() {
ty::PredicateKind::RegionOutlives(p) => p.to_string(),
ty::PredicateKind::TypeOutlives(p) => p.to_string(),
ty::PredicateKind::Atom(ty::PredicateAtom::RegionOutlives(p)) => {
p.to_string()
}
ty::PredicateKind::Atom(ty::PredicateAtom::TypeOutlives(p)) => {
p.to_string()
}
err => bug!("unexpected predicate {:?}", err),
})
.collect();
@ -85,17 +89,15 @@ fn inferred_outlives_crate(tcx: TyCtxt<'_>, crate_num: CrateNum) -> CratePredica
|(ty::OutlivesPredicate(kind1, region2), &span)| {
match kind1.unpack() {
GenericArgKind::Type(ty1) => Some((
ty::PredicateKind::TypeOutlives(ty::Binder::bind(
ty::OutlivesPredicate(ty1, region2),
))
.to_predicate(tcx),
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(ty1, region2))
.potentially_quantified(tcx, ty::PredicateKind::ForAll),
span,
)),
GenericArgKind::Lifetime(region1) => Some((
ty::PredicateKind::RegionOutlives(ty::Binder::bind(
ty::OutlivesPredicate(region1, region2),
ty::PredicateAtom::RegionOutlives(ty::OutlivesPredicate(
region1, region2,
))
.to_predicate(tcx),
.potentially_quantified(tcx, ty::PredicateKind::ForAll),
span,
)),
GenericArgKind::Const(_) => {

14
src/librustdoc/clean/auto_trait.rs
View file

@ -315,12 +315,12 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
tcx: TyCtxt<'tcx>,
pred: ty::Predicate<'tcx>,
) -> FxHashSet<GenericParamDef> {
let regions = match pred.kind() {
ty::PredicateKind::Trait(poly_trait_pred, _) => {
tcx.collect_referenced_late_bound_regions(&poly_trait_pred)
let regions = match pred.skip_binders() {
ty::PredicateAtom::Trait(poly_trait_pred, _) => {
tcx.collect_referenced_late_bound_regions(&ty::Binder::bind(poly_trait_pred))
}
ty::PredicateKind::Projection(poly_proj_pred) => {
tcx.collect_referenced_late_bound_regions(&poly_proj_pred)
ty::PredicateAtom::Projection(poly_proj_pred) => {
tcx.collect_referenced_late_bound_regions(&ty::Binder::bind(poly_proj_pred))
}
_ => return FxHashSet::default(),
};
@ -465,8 +465,8 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
.iter()
.filter(|p| {
!orig_bounds.contains(p)
|| match p.kind() {
ty::PredicateKind::Trait(pred, _) => pred.def_id() == sized_trait,
|| match p.skip_binders() {
ty::PredicateAtom::Trait(pred, _) => pred.def_id() == sized_trait,
_ => false,
}
})

94
src/librustdoc/clean/mod.rs
View file

@ -480,18 +480,18 @@ impl Clean<WherePredicate> for hir::WherePredicate<'_> {
impl<'a> Clean<Option<WherePredicate>> for ty::Predicate<'a> {
fn clean(&self, cx: &DocContext<'_>) -> Option<WherePredicate> {
match self.kind() {
ty::PredicateKind::Trait(ref pred, _) => Some(pred.clean(cx)),
ty::PredicateKind::Subtype(ref pred) => Some(pred.clean(cx)),
ty::PredicateKind::RegionOutlives(ref pred) => pred.clean(cx),
ty::PredicateKind::TypeOutlives(ref pred) => pred.clean(cx),
ty::PredicateKind::Projection(ref pred) => Some(pred.clean(cx)),
match self.skip_binders() {
ty::PredicateAtom::Trait(pred, _) => Some(ty::Binder::bind(pred).clean(cx)),
ty::PredicateAtom::RegionOutlives(pred) => pred.clean(cx),
ty::PredicateAtom::TypeOutlives(pred) => pred.clean(cx),
ty::PredicateAtom::Projection(pred) => Some(pred.clean(cx)),
ty::PredicateKind::WellFormed(..)
| ty::PredicateKind::ObjectSafe(..)
| ty::PredicateKind::ClosureKind(..)
| ty::PredicateKind::ConstEvaluatable(..)
| ty::PredicateKind::ConstEquate(..) => panic!("not user writable"),
ty::PredicateAtom::Subtype(..)
| ty::PredicateAtom::WellFormed(..)
| ty::PredicateAtom::ObjectSafe(..)
| ty::PredicateAtom::ClosureKind(..)
| ty::PredicateAtom::ConstEvaluatable(..)
| ty::PredicateAtom::ConstEquate(..) => panic!("not user writable"),
}
}
}
@ -506,20 +506,11 @@ impl<'a> Clean<WherePredicate> for ty::PolyTraitPredicate<'a> {
}
}
impl<'tcx> Clean<WherePredicate> for ty::PolySubtypePredicate<'tcx> {
fn clean(&self, _cx: &DocContext<'_>) -> WherePredicate {
panic!(
"subtype predicates are an internal rustc artifact \
and should not be seen by rustdoc"
)
}
}
impl<'tcx> Clean<Option<WherePredicate>>
for ty::PolyOutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>
for ty::OutlivesPredicate<ty::Region<'tcx>, ty::Region<'tcx>>
{
fn clean(&self, cx: &DocContext<'_>) -> Option<WherePredicate> {
let ty::OutlivesPredicate(a, b) = self.skip_binder();
let ty::OutlivesPredicate(a, b) = self;
if let (ty::ReEmpty(_), ty::ReEmpty(_)) = (a, b) {
return None;
@ -532,9 +523,9 @@ impl<'tcx> Clean<Option<WherePredicate>>
}
}
impl<'tcx> Clean<Option<WherePredicate>> for ty::PolyOutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>> {
impl<'tcx> Clean<Option<WherePredicate>> for ty::OutlivesPredicate<Ty<'tcx>, ty::Region<'tcx>> {
fn clean(&self, cx: &DocContext<'_>) -> Option<WherePredicate> {
let ty::OutlivesPredicate(ty, lt) = self.skip_binder();
let ty::OutlivesPredicate(ty, lt) = self;
if let ty::ReEmpty(_) = lt {
return None;
@ -547,9 +538,9 @@ impl<'tcx> Clean<Option<WherePredicate>> for ty::PolyOutlivesPredicate<Ty<'tcx>,
}
}
impl<'tcx> Clean<WherePredicate> for ty::PolyProjectionPredicate<'tcx> {
impl<'tcx> Clean<WherePredicate> for ty::ProjectionPredicate<'tcx> {
fn clean(&self, cx: &DocContext<'_>) -> WherePredicate {
let ty::ProjectionPredicate { projection_ty, ty } = self.skip_binder();
let ty::ProjectionPredicate { projection_ty, ty } = self;
WherePredicate::EqPredicate { lhs: projection_ty.clean(cx), rhs: ty.clean(cx) }
}
}
@ -754,19 +745,24 @@ impl<'a, 'tcx> Clean<Generics> for (&'a ty::Generics, ty::GenericPredicates<'tcx
.flat_map(|(p, _)| {
let mut projection = None;
let param_idx = (|| {
if let Some(trait_ref) = p.to_opt_poly_trait_ref() {
if let ty::Param(param) = trait_ref.skip_binder().self_ty().kind {
return Some(param.index);
match p.skip_binders() {
ty::PredicateAtom::Trait(pred, _constness) => {
if let ty::Param(param) = pred.self_ty().kind {
return Some(param.index);
}
}
} else if let Some(outlives) = p.to_opt_type_outlives() {
if let ty::Param(param) = outlives.skip_binder().0.kind {
return Some(param.index);
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(ty, _reg)) => {
if let ty::Param(param) = ty.kind {
return Some(param.index);
}
}
} else if let ty::PredicateKind::Projection(p) = p.kind() {
if let ty::Param(param) = p.skip_binder().projection_ty.self_ty().kind {
projection = Some(p);
return Some(param.index);
ty::PredicateAtom::Projection(p) => {
if let ty::Param(param) = p.projection_ty.self_ty().kind {
projection = Some(ty::Binder::bind(p));
return Some(param.index);
}
}
_ => (),
}
None
@ -1655,16 +1651,19 @@ impl<'tcx> Clean<Type> for Ty<'tcx> {
.predicates
.iter()
.filter_map(|predicate| {
let trait_ref = if let Some(tr) = predicate.to_opt_poly_trait_ref() {
tr
} else if let ty::PredicateKind::TypeOutlives(pred) = predicate.kind() {
// these should turn up at the end
if let Some(r) = pred.skip_binder().1.clean(cx) {
regions.push(GenericBound::Outlives(r));
// Note: The substs of opaque types can contain unbound variables,
// meaning that we have to use `ignore_quantifiers_with_unbound_vars` here.
let trait_ref = match predicate.bound_atom(cx.tcx).skip_binder() {
ty::PredicateAtom::Trait(tr, _constness) => {
ty::Binder::bind(tr.trait_ref)
}
return None;
} else {
return None;
ty::PredicateAtom::TypeOutlives(ty::OutlivesPredicate(_ty, reg)) => {
if let Some(r) = reg.clean(cx) {
regions.push(GenericBound::Outlives(r));
}
return None;
}
_ => return None,
};
if let Some(sized) = cx.tcx.lang_items().sized_trait() {
@ -1678,8 +1677,9 @@ impl<'tcx> Clean<Type> for Ty<'tcx> {
.predicates
.iter()
.filter_map(|pred| {
if let ty::PredicateKind::Projection(proj) = pred.kind() {
let proj = proj.skip_binder();
if let ty::PredicateAtom::Projection(proj) =
pred.bound_atom(cx.tcx).skip_binder()
{
if proj.projection_ty.trait_ref(cx.tcx)
== trait_ref.skip_binder()
{

8
src/librustdoc/clean/simplify.rs
View file

@ -141,12 +141,8 @@ fn trait_is_same_or_supertrait(cx: &DocContext<'_>, child: DefId, trait_: DefId)
.predicates
.iter()
.filter_map(|(pred, _)| {
if let ty::PredicateKind::Trait(ref pred, _) = pred.kind() {
if pred.skip_binder().trait_ref.self_ty() == self_ty {
Some(pred.def_id())
} else {
None
}
if let ty::PredicateAtom::Trait(pred, _) = pred.skip_binders() {
if pred.trait_ref.self_ty() == self_ty { Some(pred.def_id()) } else { None }
} else {
None
}

2
src/test/ui/issues/issue-26217.stderr
View file

@ -4,7 +4,7 @@ error[E0477]: the type `&'a i32` does not fulfill the required lifetime
LL | foo::<&'a i32>();
| ^^^^^^^^^^^^^^
|
= note: type must satisfy the static lifetime
= note: type must outlive any other region
error: aborting due to previous error

2
src/test/ui/specialization/min_specialization/repeated_projection_type.stderr
View file

@ -1,4 +1,4 @@
error: cannot specialize on `Binder(ProjectionPredicate(ProjectionTy { substs: [V], item_def_id: DefId(0:6 ~ repeated_projection_type[317d]::Id[0]::This[0]) }, (I,)))`
error: cannot specialize on `ProjectionPredicate(ProjectionTy { substs: [V], item_def_id: DefId(0:6 ~ repeated_projection_type[317d]::Id[0]::This[0]) }, (I,))`
--> $DIR/repeated_projection_type.rs:19:1
|
LL | / impl<I, V: Id<This = (I,)>> X for V {

11
src/tools/clippy/clippy_lints/src/future_not_send.rs
View file

@ -3,7 +3,7 @@ use rustc_hir::intravisit::FnKind;
use rustc_hir::{Body, FnDecl, HirId};
use rustc_infer::infer::TyCtxtInferExt;
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::ty::{Opaque, PredicateKind::Trait, ToPolyTraitRef};
use rustc_middle::ty::{Opaque, PredicateAtom::Trait};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::{sym, Span};
use rustc_trait_selection::traits::error_reporting::suggestions::InferCtxtExt;
@ -91,12 +91,11 @@ impl<'tcx> LateLintPass<'tcx> for FutureNotSend {
cx.tcx.infer_ctxt().enter(|infcx| {
for FulfillmentError { obligation, .. } in send_errors {
infcx.maybe_note_obligation_cause_for_async_await(db, &obligation);
if let Trait(trait_pred, _) = obligation.predicate.kind() {
let trait_ref = trait_pred.to_poly_trait_ref();
db.note(&*format!(
if let Trait(trait_pred, _) = obligation.predicate.skip_binders() {
db.note(&format!(
"`{}` doesn't implement `{}`",
trait_ref.skip_binder().self_ty(),
trait_ref.print_only_trait_path(),
trait_pred.self_ty(),
trait_pred.trait_ref.print_only_trait_path(),
));
}
}

9
src/tools/clippy/clippy_lints/src/methods/mod.rs
View file

@ -1558,13 +1558,10 @@ impl<'tcx> LateLintPass<'tcx> for Methods {
// if return type is impl trait, check the associated types
if let ty::Opaque(def_id, _) = ret_ty.kind {
// one of the associated types must be Self
for predicate in cx.tcx.predicates_of(def_id).predicates {
if let ty::PredicateKind::Projection(poly_projection_predicate) = predicate.0.kind() {
let binder = poly_projection_predicate.ty();
let associated_type = binder.skip_binder();
for &(predicate, _span) in cx.tcx.predicates_of(def_id).predicates {
if let ty::PredicateAtom::Projection(projection_predicate) = predicate.skip_binders() {
// walk the associated type and check for Self
if contains_self_ty(associated_type) {
if contains_self_ty(projection_predicate.ty) {
return;
}
}

20
src/tools/clippy/clippy_lints/src/needless_pass_by_value.rs
View file

@ -114,12 +114,12 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
let preds = traits::elaborate_predicates(cx.tcx, cx.param_env.caller_bounds().iter())
.filter(|p| !p.is_global())
.filter_map(|obligation| {
if let ty::PredicateKind::Trait(poly_trait_ref, _) = obligation.predicate.kind() {
if poly_trait_ref.def_id() == sized_trait || poly_trait_ref.skip_binder().has_escaping_bound_vars()
{
// Note that we do not want to deal with qualified predicates here.
if let ty::PredicateKind::Atom(ty::PredicateAtom::Trait(pred, _)) = obligation.predicate.kind() {
if pred.def_id() == sized_trait {
return None;
}
Some(poly_trait_ref)
Some(pred)
} else {
None
}
@ -159,14 +159,13 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
}
}
//
// * Exclude a type that is specifically bounded by `Borrow`.
// * Exclude a type whose reference also fulfills its bound. (e.g., `std::convert::AsRef`,
// `serde::Serialize`)
let (implements_borrow_trait, all_borrowable_trait) = {
let preds = preds
.iter()
.filter(|t| t.skip_binder().self_ty() == ty)
.filter(|t| t.self_ty() == ty)
.collect::<Vec<_>>();
(
@ -174,8 +173,13 @@ impl<'tcx> LateLintPass<'tcx> for NeedlessPassByValue {
!preds.is_empty() && {
let ty_empty_region = cx.tcx.mk_imm_ref(cx.tcx.lifetimes.re_root_empty, ty);
preds.iter().all(|t| {
let ty_params = &t.skip_binder().trait_ref.substs.iter().skip(1).collect::<Vec<_>>();
implements_trait(cx, ty_empty_region, t.def_id(), ty_params)
let ty_params = t
.trait_ref
.substs
.iter()
.skip(1)
.collect::<Vec<_>>();
implements_trait(cx, ty_empty_region, t.def_id(), &ty_params)
})
},
)

10
src/tools/clippy/clippy_lints/src/unit_return_expecting_ord.rs
View file

@ -4,7 +4,7 @@ use rustc_hir::def_id::DefId;
use rustc_hir::{Expr, ExprKind, StmtKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::ty;
use rustc_middle::ty::{GenericPredicates, PredicateKind, ProjectionPredicate, TraitPredicate};
use rustc_middle::ty::{GenericPredicates, PredicateAtom, ProjectionPredicate, TraitPredicate};
use rustc_session::{declare_lint_pass, declare_tool_lint};
use rustc_span::{BytePos, Span};
@ -42,8 +42,8 @@ fn get_trait_predicates_for_trait_id<'tcx>(
let mut preds = Vec::new();
for (pred, _) in generics.predicates {
if_chain! {
if let PredicateKind::Trait(poly_trait_pred, _) = pred.kind();
let trait_pred = cx.tcx.erase_late_bound_regions(&poly_trait_pred);
if let PredicateAtom::Trait(poly_trait_pred, _) = pred.skip_binders();
let trait_pred = cx.tcx.erase_late_bound_regions(&ty::Binder::bind(poly_trait_pred));
if let Some(trait_def_id) = trait_id;
if trait_def_id == trait_pred.trait_ref.def_id;
then {
@ -60,8 +60,8 @@ fn get_projection_pred<'tcx>(
pred: TraitPredicate<'tcx>,
) -> Option<ProjectionPredicate<'tcx>> {
generics.predicates.iter().find_map(|(proj_pred, _)| {
if let PredicateKind::Projection(proj_pred) = proj_pred.kind() {
let projection_pred = cx.tcx.erase_late_bound_regions(proj_pred);
if let ty::PredicateAtom::Projection(proj_pred) = proj_pred.skip_binders() {
let projection_pred = cx.tcx.erase_late_bound_regions(&ty::Binder::bind(proj_pred));
if projection_pred.projection_ty.substs == pred.trait_ref.substs {
return Some(projection_pred);
}

4
src/tools/clippy/clippy_lints/src/utils/mod.rs
View file

@ -1263,8 +1263,8 @@ pub fn is_must_use_ty<'tcx>(cx: &LateContext<'tcx>, ty: Ty<'tcx>) -> bool {
ty::Tuple(ref substs) => substs.types().any(|ty| is_must_use_ty(cx, ty)),
ty::Opaque(ref def_id, _) => {
for (predicate, _) in cx.tcx.predicates_of(*def_id).predicates {
if let ty::PredicateKind::Trait(ref poly_trait_predicate, _) = predicate.kind() {
if must_use_attr(&cx.tcx.get_attrs(poly_trait_predicate.skip_binder().trait_ref.def_id)).is_some() {
if let ty::PredicateAtom::Trait(trait_predicate, _) = predicate.skip_binders() {
if must_use_attr(&cx.tcx.get_attrs(trait_predicate.trait_ref.def_id)).is_some() {
return true;
}
}